crypto.c

   1 #include "quakedef.h"
   2 #include "crypto.h"
   3 #include "common.h"
   4 #include "thread.h"
   5
   6 #include "hmac.h"
   7 #include "libcurl.h"
   8
   9 cvar_t crypto_developer = {CVAR_SAVE, "crypto_developer", "0", "print extra info about crypto handshake"};
  10 cvar_t crypto_aeslevel = {CVAR_SAVE, "crypto_aeslevel", "1", "whether to support AES encryption in authenticated connections (0 = no, 1 = supported, 2 = requested, 3 = required)"};
  11
  12 cvar_t crypto_servercpupercent = {CVAR_SAVE, "crypto_servercpupercent", "10", "allowed crypto CPU load in percent for server operation (0 = no limit, faster)"};
  13 cvar_t crypto_servercpumaxtime = {CVAR_SAVE, "crypto_servercpumaxtime", "0.01", "maximum allowed crypto CPU time per frame (0 = no limit)"};
  14 cvar_t crypto_servercpudebug = {CVAR_SAVE, "crypto_servercpudebug", "0", "print statistics about time usage by crypto"};
  15 static double crypto_servercpu_accumulator = 0;
  16 static double crypto_servercpu_lastrealtime = 0;
  17
  18 extern cvar_t net_sourceaddresscheck;
  19
  20 int crypto_keyfp_recommended_length;
  21 static const char *crypto_idstring = NULL;
  22 static char crypto_idstring_buf[512];
  23
  24
  25 #define PROTOCOL_D0_BLIND_ID FOURCC_D0PK
  26 #define PROTOCOL_VLEN (('v' << 0) | ('l' << 8) | ('e' << 16) | ('n' << 24))
  27
  28 // BEGIN stuff shared with crypto-keygen-standalone
  29 #define FOURCC_D0PK (('d' << 0) | ('0' << 8) | ('p' << 16) | ('k' << 24))
  30 #define FOURCC_D0SK (('d' << 0) | ('0' << 8) | ('s' << 16) | ('k' << 24))
  31 #define FOURCC_D0PI (('d' << 0) | ('0' << 8) | ('p' << 16) | ('i' << 24))
  32 #define FOURCC_D0SI (('d' << 0) | ('0' << 8) | ('s' << 16) | ('i' << 24))
  33 #define FOURCC_D0IQ (('d' << 0) | ('0' << 8) | ('i' << 16) | ('q' << 24))
  34 #define FOURCC_D0IR (('d' << 0) | ('0' << 8) | ('i' << 16) | ('r' << 24))
  35 #define FOURCC_D0ER (('d' << 0) | ('0' << 8) | ('e' << 16) | ('r' << 24))
  36 #define FOURCC_D0IC (('d' << 0) | ('0' << 8) | ('i' << 16) | ('c' << 24))
  37
  38 static unsigned long Crypto_LittleLong(const char *data)
  39 {
  40         return
  41                 ((unsigned char) data[0]) |
  42                 (((unsigned char) data[1]) << 8) |
  43                 (((unsigned char) data[2]) << 16) |
  44                 (((unsigned char) data[3]) << 24);
  45 }
  46
  47 static void Crypto_UnLittleLong(char *data, unsigned long l)
  48 {
  49         data[0] = l & 0xFF;
  50         data[1] = (l >> 8) & 0xFF;
  51         data[2] = (l >> 16) & 0xFF;
  52         data[3] = (l >> 24) & 0xFF;
  53 }
  54
  55 static size_t Crypto_ParsePack(const char *buf, size_t len, unsigned long header, const char **lumps, size_t *lumpsize, size_t nlumps)
  56 {
  57         size_t i;
  58         size_t pos;
  59         pos = 0;
  60         if(header)
  61         {
  62                 if(len < 4)
  63                         return 0;
  64                 if(Crypto_LittleLong(buf) != header)
  65                         return 0;
  66                 pos += 4;
  67         }
  68         for(i = 0; i < nlumps; ++i)
  69         {
  70                 if(pos + 4 > len)
  71                         return 0;
  72                 lumpsize[i] = Crypto_LittleLong(&buf[pos]);
  73                 pos += 4;
  74                 if(pos + lumpsize[i] > len)
  75                         return 0;
  76                 lumps[i] = &buf[pos];
  77                 pos += lumpsize[i];
  78         }
  79         return pos;
  80 }
  81
  82 static size_t Crypto_UnParsePack(char *buf, size_t len, unsigned long header, const char *const *lumps, const size_t *lumpsize, size_t nlumps)
  83 {
  84         size_t i;
  85         size_t pos;
  86         pos = 0;
  87         if(header)
  88         {
  89                 if(len < 4)
  90                         return 0;
  91                 Crypto_UnLittleLong(buf, header);
  92                 pos += 4;
  93         }
  94         for(i = 0; i < nlumps; ++i)
  95         {
  96                 if(pos + 4 + lumpsize[i] > len)
  97                         return 0;
  98                 Crypto_UnLittleLong(&buf[pos], (unsigned long)lumpsize[i]);
  99                 pos += 4;
 100                 memcpy(&buf[pos], lumps[i], lumpsize[i]);
 101                 pos += lumpsize[i];
 102         }
 103         return pos;
 104 }
 105 // END stuff shared with xonotic-keygen
 106
 107 #define USE_AES
 108
 109 #ifdef LINK_TO_CRYPTO
 110
 111 #include <d0_blind_id/d0_blind_id.h>
 112
 113 #define d0_blind_id_dll 1
 114 #define Crypto_OpenLibrary() true
 115 #define Crypto_CloseLibrary()
 116
 117 #define qd0_blind_id_new d0_blind_id_new
 118 #define qd0_blind_id_free d0_blind_id_free
 119 //#define qd0_blind_id_clear d0_blind_id_clear
 120 #define qd0_blind_id_copy d0_blind_id_copy
 121 //#define qd0_blind_id_generate_private_key d0_blind_id_generate_private_key
 122 //#define qd0_blind_id_generate_private_key_fastreject d0_blind_id_generate_private_key_fastreject
 123 //#define qd0_blind_id_read_private_key d0_blind_id_read_private_key
 124 #define qd0_blind_id_read_public_key d0_blind_id_read_public_key
 125 //#define qd0_blind_id_write_private_key d0_blind_id_write_private_key
 126 //#define qd0_blind_id_write_public_key d0_blind_id_write_public_key
 127 #define qd0_blind_id_fingerprint64_public_key d0_blind_id_fingerprint64_public_key
 128 //#define qd0_blind_id_generate_private_id_modulus d0_blind_id_generate_private_id_modulus
 129 #define qd0_blind_id_read_private_id_modulus d0_blind_id_read_private_id_modulus
 130 //#define qd0_blind_id_write_private_id_modulus d0_blind_id_write_private_id_modulus
 131 #define qd0_blind_id_generate_private_id_start d0_blind_id_generate_private_id_start
 132 #define qd0_blind_id_generate_private_id_request d0_blind_id_generate_private_id_request
 133 //#define qd0_blind_id_answer_private_id_request d0_blind_id_answer_private_id_request
 134 #define qd0_blind_id_finish_private_id_request d0_blind_id_finish_private_id_request
 135 //#define qd0_blind_id_read_private_id_request_camouflage d0_blind_id_read_private_id_request_camouflage
 136 //#define qd0_blind_id_write_private_id_request_camouflage d0_blind_id_write_private_id_request_camouflage
 137 #define qd0_blind_id_read_private_id d0_blind_id_read_private_id
 138 //#define qd0_blind_id_read_public_id d0_blind_id_read_public_id
 139 #define qd0_blind_id_write_private_id d0_blind_id_write_private_id
 140 //#define qd0_blind_id_write_public_id d0_blind_id_write_public_id
 141 #define qd0_blind_id_authenticate_with_private_id_start d0_blind_id_authenticate_with_private_id_start
 142 #define qd0_blind_id_authenticate_with_private_id_challenge d0_blind_id_authenticate_with_private_id_challenge
 143 #define qd0_blind_id_authenticate_with_private_id_response d0_blind_id_authenticate_with_private_id_response
 144 #define qd0_blind_id_authenticate_with_private_id_verify d0_blind_id_authenticate_with_private_id_verify
 145 #define qd0_blind_id_fingerprint64_public_id d0_blind_id_fingerprint64_public_id
 146 #define qd0_blind_id_sessionkey_public_id d0_blind_id_sessionkey_public_id
 147 #define qd0_blind_id_INITIALIZE d0_blind_id_INITIALIZE
 148 #define qd0_blind_id_SHUTDOWN d0_blind_id_SHUTDOWN
 149 #define qd0_blind_id_util_sha256 d0_blind_id_util_sha256
 150 #define qd0_blind_id_sign_with_private_id_sign d0_blind_id_sign_with_private_id_sign
 151 #define qd0_blind_id_sign_with_private_id_sign_detached d0_blind_id_sign_with_private_id_sign_detached
 152 #define qd0_blind_id_setmallocfuncs d0_blind_id_setmallocfuncs
 153 #define qd0_blind_id_setmutexfuncs d0_blind_id_setmutexfuncs
 154 #define qd0_blind_id_verify_public_id d0_blind_id_verify_public_id
 155 #define qd0_blind_id_verify_private_id d0_blind_id_verify_private_id
 156
 157 #else
 158
 159 // d0_blind_id interface
 160 #define D0_EXPORT
 161 #ifdef __GNUC__
 162 #define D0_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 163 #else
 164 #define D0_WARN_UNUSED_RESULT
 165 #endif
 166 #define D0_BOOL int
 167
 168 typedef void *(d0_malloc_t)(size_t len);
 169 typedef void (d0_free_t)(void *p);
 170 typedef void *(d0_createmutex_t)(void);
 171 typedef void (d0_destroymutex_t)(void *);
 172 typedef int (d0_lockmutex_t)(void *); // zero on success
 173 typedef int (d0_unlockmutex_t)(void *); // zero on success
 174
 175 typedef struct d0_blind_id_s d0_blind_id_t;
 176 typedef D0_BOOL (*d0_fastreject_function) (const d0_blind_id_t *ctx, void *pass);
 177 static D0_EXPORT D0_WARN_UNUSED_RESULT d0_blind_id_t *(*qd0_blind_id_new) (void);
 178 static D0_EXPORT void (*qd0_blind_id_free) (d0_blind_id_t *a);
 179 //static D0_EXPORT void (*qd0_blind_id_clear) (d0_blind_id_t *ctx);
 180 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_copy) (d0_blind_id_t *ctx, const d0_blind_id_t *src);
 181 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key) (d0_blind_id_t *ctx, int k);
 182 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key_fastreject) (d0_blind_id_t *ctx, int k, d0_fastreject_function reject, void *pass);
 183 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_key) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 184 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_public_key) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 185 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 186 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_public_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 187 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_fingerprint64_public_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 188 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_modulus) (d0_blind_id_t *ctx);
 189 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id_modulus) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 190 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id_modulus) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 191 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_start) (d0_blind_id_t *ctx);
 192 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_request) (d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 193 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_answer_private_id_request) (const d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
 194 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_finish_private_id_request) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 195 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id_request_camouflage) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 196 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id_request_camouflage) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 197 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 198 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_public_id) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 199 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 200 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 201 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_start) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 202 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_challenge) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen, D0_BOOL *status);
 203 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_response) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
 204 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_verify) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status);
 205 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_fingerprint64_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 206 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sessionkey_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen); // can only be done after successful key exchange, this performs a modpow; key length is limited by SHA_DIGESTSIZE for now; also ONLY valid after successful d0_blind_id_authenticate_with_private_id_verify/d0_blind_id_fingerprint64_public_id
 207 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_INITIALIZE) (void);
 208 static D0_EXPORT void (*qd0_blind_id_SHUTDOWN) (void);
 209 static D0_EXPORT void (*qd0_blind_id_util_sha256) (char *out, const char *in, size_t n);
 210 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sign_with_private_id_sign) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 211 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sign_with_private_id_sign_detached) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 212 static D0_EXPORT void (*qd0_blind_id_setmallocfuncs)(d0_malloc_t *m, d0_free_t *f);
 213 static D0_EXPORT void (*qd0_blind_id_setmutexfuncs)(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u);
 214 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_public_id)(const d0_blind_id_t *ctx, D0_BOOL *status);
 215 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_private_id)(const d0_blind_id_t *ctx);
 216 static dllfunction_t d0_blind_id_funcs[] =
 217 {
 218         {"d0_blind_id_new", (void **) &qd0_blind_id_new},
 219         {"d0_blind_id_free", (void **) &qd0_blind_id_free},
 220         //{"d0_blind_id_clear", (void **) &qd0_blind_id_clear},
 221         {"d0_blind_id_copy", (void **) &qd0_blind_id_copy},
 222         //{"d0_blind_id_generate_private_key", (void **) &qd0_blind_id_generate_private_key},
 223         //{"d0_blind_id_generate_private_key_fastreject", (void **) &qd0_blind_id_generate_private_key_fastreject},
 224         //{"d0_blind_id_read_private_key", (void **) &qd0_blind_id_read_private_key},
 225         {"d0_blind_id_read_public_key", (void **) &qd0_blind_id_read_public_key},
 226         //{"d0_blind_id_write_private_key", (void **) &qd0_blind_id_write_private_key},
 227         //{"d0_blind_id_write_public_key", (void **) &qd0_blind_id_write_public_key},
 228         {"d0_blind_id_fingerprint64_public_key", (void **) &qd0_blind_id_fingerprint64_public_key},
 229         //{"d0_blind_id_generate_private_id_modulus", (void **) &qd0_blind_id_generate_private_id_modulus},
 230         {"d0_blind_id_read_private_id_modulus", (void **) &qd0_blind_id_read_private_id_modulus},
 231         //{"d0_blind_id_write_private_id_modulus", (void **) &qd0_blind_id_write_private_id_modulus},
 232         {"d0_blind_id_generate_private_id_start", (void **) &qd0_blind_id_generate_private_id_start},
 233         {"d0_blind_id_generate_private_id_request", (void **) &qd0_blind_id_generate_private_id_request},
 234         //{"d0_blind_id_answer_private_id_request", (void **) &qd0_blind_id_answer_private_id_request},
 235         {"d0_blind_id_finish_private_id_request", (void **) &qd0_blind_id_finish_private_id_request},
 236         //{"d0_blind_id_read_private_id_request_camouflage", (void **) &qd0_blind_id_read_private_id_request_camouflage},
 237         //{"d0_blind_id_write_private_id_request_camouflage", (void **) &qd0_blind_id_write_private_id_request_camouflage},
 238         {"d0_blind_id_read_private_id", (void **) &qd0_blind_id_read_private_id},
 239         //{"d0_blind_id_read_public_id", (void **) &qd0_blind_id_read_public_id},
 240         {"d0_blind_id_write_private_id", (void **) &qd0_blind_id_write_private_id},
 241         //{"d0_blind_id_write_public_id", (void **) &qd0_blind_id_write_public_id},
 242         {"d0_blind_id_authenticate_with_private_id_start", (void **) &qd0_blind_id_authenticate_with_private_id_start},
 243         {"d0_blind_id_authenticate_with_private_id_challenge", (void **) &qd0_blind_id_authenticate_with_private_id_challenge},
 244         {"d0_blind_id_authenticate_with_private_id_response", (void **) &qd0_blind_id_authenticate_with_private_id_response},
 245         {"d0_blind_id_authenticate_with_private_id_verify", (void **) &qd0_blind_id_authenticate_with_private_id_verify},
 246         {"d0_blind_id_fingerprint64_public_id", (void **) &qd0_blind_id_fingerprint64_public_id},
 247         {"d0_blind_id_sessionkey_public_id", (void **) &qd0_blind_id_sessionkey_public_id},
 248         {"d0_blind_id_INITIALIZE", (void **) &qd0_blind_id_INITIALIZE},
 249         {"d0_blind_id_SHUTDOWN", (void **) &qd0_blind_id_SHUTDOWN},
 250         {"d0_blind_id_util_sha256", (void **) &qd0_blind_id_util_sha256},
 251         {"d0_blind_id_sign_with_private_id_sign", (void **) &qd0_blind_id_sign_with_private_id_sign},
 252         {"d0_blind_id_sign_with_private_id_sign_detached", (void **) &qd0_blind_id_sign_with_private_id_sign_detached},
 253         {"d0_blind_id_setmallocfuncs", (void **) &qd0_blind_id_setmallocfuncs},
 254         {"d0_blind_id_setmutexfuncs", (void **) &qd0_blind_id_setmutexfuncs},
 255         {"d0_blind_id_verify_public_id", (void **) &qd0_blind_id_verify_public_id},
 256         {"d0_blind_id_verify_private_id", (void **) &qd0_blind_id_verify_private_id},
 257         {NULL, NULL}
 258 };
 259 // end of d0_blind_id interface
 260
 261 static dllhandle_t d0_blind_id_dll = NULL;
 262 static qboolean Crypto_OpenLibrary (void)
 263 {
 264         const char* dllnames [] =
 265         {
 266 #if defined(WIN32)
 267                 "libd0_blind_id-0.dll",
 268 #elif defined(MACOSX)
 269                 "libd0_blind_id.0.dylib",
 270 #else
 271                 "libd0_blind_id.so.0",
 272                 "libd0_blind_id.so", // FreeBSD
 273 #endif
 274                 NULL
 275         };
 276
 277         // Already loaded?
 278         if (d0_blind_id_dll)
 279                 return true;
 280
 281         // Load the DLL
 282         return Sys_LoadLibrary (dllnames, &d0_blind_id_dll, d0_blind_id_funcs);
 283 }
 284
 285 static void Crypto_CloseLibrary (void)
 286 {
 287         Sys_UnloadLibrary (&d0_blind_id_dll);
 288 }
 289
 290 #endif
 291
 292 #ifdef LINK_TO_CRYPTO_RIJNDAEL
 293
 294 #include <d0_blind_id/d0_rijndael.h>
 295
 296 #define d0_rijndael_dll 1
 297 #define Crypto_Rijndael_OpenLibrary() true
 298 #define Crypto_Rijndael_CloseLibrary()
 299
 300 #define qd0_rijndael_setup_encrypt d0_rijndael_setup_encrypt
 301 #define qd0_rijndael_setup_decrypt d0_rijndael_setup_decrypt
 302 #define qd0_rijndael_encrypt d0_rijndael_encrypt
 303 #define qd0_rijndael_decrypt d0_rijndael_decrypt
 304
 305 #else
 306
 307 // no need to do the #define dance here, as the upper part declares out macros either way
 308
 309 D0_EXPORT int (*qd0_rijndael_setup_encrypt) (unsigned long *rk, const unsigned char *key,
 310   int keybits);
 311 D0_EXPORT int (*qd0_rijndael_setup_decrypt) (unsigned long *rk, const unsigned char *key,
 312   int keybits);
 313 D0_EXPORT void (*qd0_rijndael_encrypt) (const unsigned long *rk, int nrounds,
 314   const unsigned char plaintext[16], unsigned char ciphertext[16]);
 315 D0_EXPORT void (*qd0_rijndael_decrypt) (const unsigned long *rk, int nrounds,
 316   const unsigned char ciphertext[16], unsigned char plaintext[16]);
 317 #define D0_RIJNDAEL_KEYLENGTH(keybits) ((keybits)/8)
 318 #define D0_RIJNDAEL_RKLENGTH(keybits)  ((keybits)/8+28)
 319 #define D0_RIJNDAEL_NROUNDS(keybits)   ((keybits)/32+6)
 320 static dllfunction_t d0_rijndael_funcs[] =
 321 {
 322         {"d0_rijndael_setup_decrypt", (void **) &qd0_rijndael_setup_decrypt},
 323         {"d0_rijndael_setup_encrypt", (void **) &qd0_rijndael_setup_encrypt},
 324         {"d0_rijndael_decrypt", (void **) &qd0_rijndael_decrypt},
 325         {"d0_rijndael_encrypt", (void **) &qd0_rijndael_encrypt},
 326         {NULL, NULL}
 327 };
 328 // end of d0_blind_id interface
 329
 330 static dllhandle_t d0_rijndael_dll = NULL;
 331 static qboolean Crypto_Rijndael_OpenLibrary (void)
 332 {
 333         const char* dllnames [] =
 334         {
 335 #if defined(WIN32)
 336                 "libd0_rijndael-0.dll",
 337 #elif defined(MACOSX)
 338                 "libd0_rijndael.0.dylib",
 339 #else
 340                 "libd0_rijndael.so.0",
 341                 "libd0_rijndael.so", // FreeBSD
 342 #endif
 343                 NULL
 344         };
 345
 346         // Already loaded?
 347         if (d0_rijndael_dll)
 348                 return true;
 349
 350         // Load the DLL
 351         return Sys_LoadLibrary (dllnames, &d0_rijndael_dll, d0_rijndael_funcs);
 352 }
 353
 354 static void Crypto_Rijndael_CloseLibrary (void)
 355 {
 356         Sys_UnloadLibrary (&d0_rijndael_dll);
 357 }
 358
 359 #endif
 360
 361 // various helpers
 362 void sha256(unsigned char *out, const unsigned char *in, int n)
 363 {
 364         qd0_blind_id_util_sha256((char *) out, (const char *) in, n);
 365 }
 366
 367 static size_t Crypto_LoadFile(const char *path, char *buf, size_t nmax, qboolean inuserdir)
 368 {
 369         char vabuf[1024];
 370         qfile_t *f = NULL;
 371         fs_offset_t n;
 372         if(inuserdir)
 373                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", *fs_userdir ? fs_userdir : fs_basedir, path), "rb", false);
 374         else
 375                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", fs_basedir, path), "rb", false);
 376         if(!f)
 377                 return 0;
 378         n = FS_Read(f, buf, nmax);
 379         if(n < 0)
 380                 n = 0;
 381         FS_Close(f);
 382         return (size_t) n;
 383 }
 384
 385 static qboolean PutWithNul(char **data, size_t *len, const char *str)
 386 {
 387         // invariant: data points to insertion point
 388         size_t l = strlen(str);
 389         if(l >= *len)
 390                 return false;
 391         memcpy(*data, str, l+1);
 392         *data += l+1;
 393         *len -= l+1;
 394         return true;
 395 }
 396
 397 static const char *GetUntilNul(const char **data, size_t *len)
 398 {
 399         // invariant: data points to next character to take
 400         const char *data_save = *data;
 401         size_t n;
 402         const char *p;
 403
 404         if(!*data)
 405                 return NULL;
 406
 407         if(!*len)
 408         {
 409                 *data = NULL;
 410                 return NULL;
 411         }
 412
 413         p = (const char *) memchr(*data, 0, *len);
 414         if(!p) // no terminating NUL
 415         {
 416                 *data = NULL;
 417                 *len = 0;
 418                 return NULL;
 419         }
 420         n = (p - *data) + 1;
 421         *len -= n;
 422         *data += n;
 423         if(*len == 0)
 424                 *data = NULL;
 425         return (const char *) data_save;
 426 }
 427
 428 // d0pk reading
 429 static d0_blind_id_t *Crypto_ReadPublicKey(char *buf, size_t len)
 430 {
 431         d0_blind_id_t *pk = NULL;
 432         const char *p[2];
 433         size_t l[2];
 434         if(Crypto_ParsePack(buf, len, FOURCC_D0PK, p, l, 2))
 435         {
 436                 pk = qd0_blind_id_new();
 437                 if(pk)
 438                         if(qd0_blind_id_read_public_key(pk, p[0], l[0]))
 439                                 if(qd0_blind_id_read_private_id_modulus(pk, p[1], l[1]))
 440                                         return pk;
 441         }
 442         if(pk)
 443                 qd0_blind_id_free(pk);
 444         return NULL;
 445 }
 446
 447 // d0si reading
 448 static qboolean Crypto_AddPrivateKey(d0_blind_id_t *pk, char *buf, size_t len)
 449 {
 450         const char *p[1];
 451         size_t l[1];
 452         if(Crypto_ParsePack(buf, len, FOURCC_D0SI, p, l, 1))
 453         {
 454                 if(qd0_blind_id_read_private_id(pk, p[0], l[0]))
 455                         return true;
 456         }
 457         return false;
 458 }
 459
 460 #define MAX_PUBKEYS 16
 461 static d0_blind_id_t *pubkeys[MAX_PUBKEYS];
 462 static char pubkeys_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 463 static qboolean pubkeys_havepriv[MAX_PUBKEYS];
 464 static qboolean pubkeys_havesig[MAX_PUBKEYS];
 465 static char pubkeys_priv_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 466 static char challenge_append[1400];
 467 static size_t challenge_append_length;
 468
 469 static int keygen_i = -1;
 470 static char keygen_buf[8192];
 471
 472 #define MAX_CRYPTOCONNECTS 16
 473 #define CRYPTOCONNECT_NONE 0
 474 #define CRYPTOCONNECT_PRECONNECT 1
 475 #define CRYPTOCONNECT_CONNECT 2
 476 #define CRYPTOCONNECT_RECONNECT 3
 477 #define CRYPTOCONNECT_DUPLICATE 4
 478 typedef struct server_cryptoconnect_s
 479 {
 480         double lasttime;
 481         lhnetaddress_t address;
 482         crypto_t crypto;
 483         int next_step;
 484 }
 485 server_cryptoconnect_t;
 486 static server_cryptoconnect_t cryptoconnects[MAX_CRYPTOCONNECTS];
 487
 488 static int cdata_id = 0;
 489 typedef struct
 490 {
 491         d0_blind_id_t *id;
 492         int s, c;
 493         int next_step;
 494         char challenge[2048];
 495         char wantserver_idfp[FP64_SIZE+1];
 496         qboolean wantserver_aes;
 497         qboolean wantserver_issigned;
 498         int cdata_id;
 499 }
 500 crypto_data_t;
 501
 502 // crypto specific helpers
 503 #define CDATA ((crypto_data_t *) crypto->data)
 504 #define MAKE_CDATA if(!crypto->data) crypto->data = Z_Malloc(sizeof(crypto_data_t))
 505 #define CLEAR_CDATA if(crypto->data) { if(CDATA->id) qd0_blind_id_free(CDATA->id); Z_Free(crypto->data); } crypto->data = NULL
 506
 507 static crypto_t *Crypto_ServerFindInstance(lhnetaddress_t *peeraddress, qboolean allow_create)
 508 {
 509         crypto_t *crypto;
 510         int i, best;
 511
 512         if(!d0_blind_id_dll)
 513                 return NULL; // no support
 514
 515         for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 516                 if(LHNETADDRESS_Compare(peeraddress, &cryptoconnects[i].address))
 517                         break;
 518         if(i < MAX_CRYPTOCONNECTS && (allow_create || cryptoconnects[i].crypto.data))
 519         {
 520                 crypto = &cryptoconnects[i].crypto;
 521                 cryptoconnects[i].lasttime = realtime;
 522                 return crypto;
 523         }
 524         if(!allow_create)
 525                 return NULL;
 526         best = 0;
 527         for(i = 1; i < MAX_CRYPTOCONNECTS; ++i)
 528                 if(cryptoconnects[i].lasttime < cryptoconnects[best].lasttime)
 529                         best = i;
 530         crypto = &cryptoconnects[best].crypto;
 531         cryptoconnects[best].lasttime = realtime;
 532         memcpy(&cryptoconnects[best].address, peeraddress, sizeof(cryptoconnects[best].address));
 533         CLEAR_CDATA;
 534         return crypto;
 535 }
 536
 537 qboolean Crypto_FinishInstance(crypto_t *out, crypto_t *crypto)
 538 {
 539         // no check needed here (returned pointers are only used in prefilled fields)
 540         if(!crypto || !crypto->authenticated)
 541         {
 542                 Con_Printf("Passed an invalid crypto connect instance\n");
 543                 memset(out, 0, sizeof(*out));
 544                 return false;
 545         }
 546         CLEAR_CDATA;
 547         memcpy(out, crypto, sizeof(*out));
 548         memset(crypto, 0, sizeof(*crypto));
 549         return true;
 550 }
 551
 552 crypto_t *Crypto_ServerGetInstance(lhnetaddress_t *peeraddress)
 553 {
 554         // no check needed here (returned pointers are only used in prefilled fields)
 555         return Crypto_ServerFindInstance(peeraddress, false);
 556 }
 557
 558 typedef struct crypto_storedhostkey_s
 559 {
 560         struct crypto_storedhostkey_s *next;
 561         lhnetaddress_t addr;
 562         int keyid;
 563         char idfp[FP64_SIZE+1];
 564         int aeslevel;
 565         qboolean issigned;
 566 }
 567 crypto_storedhostkey_t;
 568 static crypto_storedhostkey_t *crypto_storedhostkey_hashtable[CRYPTO_HOSTKEY_HASHSIZE];
 569
 570 static void Crypto_InitHostKeys(void)
 571 {
 572         int i;
 573         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 574                 crypto_storedhostkey_hashtable[i] = NULL;
 575 }
 576
 577 static void Crypto_ClearHostKeys(void)
 578 {
 579         int i;
 580         crypto_storedhostkey_t *hk, *hkn;
 581         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 582         {
 583                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hkn)
 584                 {
 585                         hkn = hk->next;
 586                         Z_Free(hk);
 587                 }
 588                 crypto_storedhostkey_hashtable[i] = NULL;
 589         }
 590 }
 591
 592 static qboolean Crypto_ClearHostKey(lhnetaddress_t *peeraddress)
 593 {
 594         char buf[128];
 595         int hashindex;
 596         crypto_storedhostkey_t **hkp;
 597         qboolean found = false;
 598
 599         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 600         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 601         for(hkp = &crypto_storedhostkey_hashtable[hashindex]; *hkp && LHNETADDRESS_Compare(&((*hkp)->addr), peeraddress); hkp = &((*hkp)->next));
 602
 603         if(*hkp)
 604         {
 605                 crypto_storedhostkey_t *hk = *hkp;
 606                 *hkp = hk->next;
 607                 Z_Free(hk);
 608                 found = true;
 609         }
 610
 611         return found;
 612 }
 613
 614 static void Crypto_StoreHostKey(lhnetaddress_t *peeraddress, const char *keystring, qboolean complain)
 615 {
 616         char buf[128];
 617         int hashindex;
 618         crypto_storedhostkey_t *hk;
 619         int keyid;
 620         char idfp[FP64_SIZE+1];
 621         int aeslevel;
 622         qboolean issigned;
 623
 624         if(!d0_blind_id_dll)
 625                 return;
 626
 627         // syntax of keystring:
 628         // aeslevel id@key id@key ...
 629
 630         if(!*keystring)
 631                 return;
 632         aeslevel = bound(0, *keystring - '0', 3);
 633         while(*keystring && *keystring != ' ')
 634                 ++keystring;
 635
 636         keyid = -1;
 637         issigned = false;
 638         while(*keystring && keyid < 0)
 639         {
 640                 // id@key
 641                 const char *idstart, *idend, *keystart, *keyend;
 642                 qboolean thisissigned = true;
 643                 ++keystring; // skip the space
 644                 idstart = keystring;
 645                 while(*keystring && *keystring != ' ' && *keystring != '@')
 646                         ++keystring;
 647                 idend = keystring;
 648                 if(!*keystring)
 649                         break;
 650                 ++keystring;
 651                 keystart = keystring;
 652                 while(*keystring && *keystring != ' ')
 653                         ++keystring;
 654                 keyend = keystring;
 655
 656                 if (keystart[0] == '~')
 657                 {
 658                         thisissigned = false;
 659                         ++keystart;
 660                 }
 661
 662                 if(idend - idstart == FP64_SIZE && keyend - keystart == FP64_SIZE)
 663                 {
 664                         int thiskeyid;
 665                         for(thiskeyid = MAX_PUBKEYS - 1; thiskeyid >= 0; --thiskeyid)
 666                                 if(pubkeys[thiskeyid])
 667                                         if(!memcmp(pubkeys_fp64[thiskeyid], keystart, FP64_SIZE))
 668                                         {
 669                                                 memcpy(idfp, idstart, FP64_SIZE);
 670                                                 idfp[FP64_SIZE] = 0;
 671                                                 keyid = thiskeyid;
 672                                                 issigned = thisissigned;
 673                                                 break;
 674                                         }
 675                         // If this failed, keyid will be -1.
 676                 }
 677         }
 678
 679         if(keyid < 0)
 680                 return;
 681
 682         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 683         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 684         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 685
 686         if(hk)
 687         {
 688                 if(complain)
 689                 {
 690                         if(hk->keyid != keyid || memcmp(hk->idfp, idfp, FP64_SIZE+1))
 691                                 Con_Printf("Server %s tried to change the host key to a value not in the host cache. Connecting to it will fail. To accept the new host key, do crypto_hostkey_clear %s\n", buf, buf);
 692                         if(hk->aeslevel > aeslevel)
 693                                 Con_Printf("Server %s tried to reduce encryption status, not accepted. Connecting to it will fail. To accept, do crypto_hostkey_clear %s\n", buf, buf);
 694                         if(hk->issigned > issigned)
 695                                 Con_Printf("Server %s tried to reduce signature status, not accepted. Connecting to it will fail. To accept, do crypto_hostkey_clear %s\n", buf, buf);
 696                 }
 697                 hk->aeslevel = max(aeslevel, hk->aeslevel);
 698                 hk->issigned = issigned;
 699                 return;
 700         }
 701
 702         // great, we did NOT have it yet
 703         hk = (crypto_storedhostkey_t *) Z_Malloc(sizeof(*hk));
 704         memcpy(&hk->addr, peeraddress, sizeof(hk->addr));
 705         hk->keyid = keyid;
 706         memcpy(hk->idfp, idfp, FP64_SIZE+1);
 707         hk->next = crypto_storedhostkey_hashtable[hashindex];
 708         hk->aeslevel = aeslevel;
 709         hk->issigned = issigned;
 710         crypto_storedhostkey_hashtable[hashindex] = hk;
 711 }
 712
 713 qboolean Crypto_RetrieveHostKey(lhnetaddress_t *peeraddress, int *keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, int *aeslevel, qboolean *issigned)
 714 {
 715         char buf[128];
 716         int hashindex;
 717         crypto_storedhostkey_t *hk;
 718
 719         if(!d0_blind_id_dll)
 720                 return false;
 721
 722         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 723         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 724         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 725
 726         if(!hk)
 727                 return false;
 728
 729         if(keyid)
 730                 *keyid = hk->keyid;
 731         if(keyfp)
 732                 strlcpy(keyfp, pubkeys_fp64[hk->keyid], keyfplen);
 733         if(idfp)
 734                 strlcpy(idfp, hk->idfp, idfplen);
 735         if(aeslevel)
 736                 *aeslevel = hk->aeslevel;
 737         if(issigned)
 738                 *issigned = hk->issigned;
 739
 740         return true;
 741 }
 742 int Crypto_RetrieveLocalKey(int keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, qboolean *issigned) // return value: -1 if more to come, +1 if valid, 0 if end of list
 743 {
 744         if(keyid < 0 || keyid >= MAX_PUBKEYS)
 745                 return 0;
 746         if(keyfp)
 747                 *keyfp = 0;
 748         if(idfp)
 749                 *idfp = 0;
 750         if(!pubkeys[keyid])
 751                 return -1;
 752         if(keyfp)
 753                 strlcpy(keyfp, pubkeys_fp64[keyid], keyfplen);
 754         if(idfp)
 755                 if(pubkeys_havepriv[keyid])
 756                         strlcpy(idfp, pubkeys_priv_fp64[keyid], idfplen);
 757         if(issigned)
 758                 *issigned = pubkeys_havesig[keyid];
 759         return 1;
 760 }
 761 // end
 762
 763 // init/shutdown code
 764 static void Crypto_BuildChallengeAppend(void)
 765 {
 766         char *p, *lengthptr, *startptr;
 767         size_t n;
 768         int i;
 769         p = challenge_append;
 770         n = sizeof(challenge_append);
 771         Crypto_UnLittleLong(p, PROTOCOL_VLEN);
 772         p += 4;
 773         n -= 4;
 774         lengthptr = p;
 775         Crypto_UnLittleLong(p, 0);
 776         p += 4;
 777         n -= 4;
 778         Crypto_UnLittleLong(p, PROTOCOL_D0_BLIND_ID);
 779         p += 4;
 780         n -= 4;
 781         startptr = p;
 782         for(i = 0; i < MAX_PUBKEYS; ++i)
 783                 if(pubkeys_havepriv[i])
 784                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 785         PutWithNul(&p, &n, "");
 786         for(i = 0; i < MAX_PUBKEYS; ++i)
 787                 if(!pubkeys_havepriv[i] && pubkeys[i])
 788                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 789         Crypto_UnLittleLong(lengthptr, p - startptr);
 790         challenge_append_length = p - challenge_append;
 791 }
 792
 793 static qboolean Crypto_SavePubKeyTextFile(int i)
 794 {
 795         qfile_t *f;
 796         char vabuf[1024];
 797
 798         if(!pubkeys_havepriv[i])
 799                 return false;
 800         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d-public-fp%s.txt", *fs_userdir ? fs_userdir : fs_basedir, i, sessionid.string), "w", false);
 801         if(!f)
 802                 return false;
 803
 804         // we ignore errors for this file, as it's not necessary to have
 805         FS_Printf(f, "ID-Fingerprint: %s\n", pubkeys_priv_fp64[i]);
 806         FS_Printf(f, "ID-Is-Signed: %s\n", pubkeys_havesig[i] ? "yes" : "no");
 807         FS_Printf(f, "ID-Is-For-Key: %s\n", pubkeys_fp64[i]);
 808         FS_Printf(f, "\n");
 809         FS_Printf(f, "This is a PUBLIC ID file for DarkPlaces.\n");
 810         FS_Printf(f, "You are free to share this file or its contents.\n");
 811         FS_Printf(f, "\n");
 812         FS_Printf(f, "This file will be automatically generated again if deleted.\n");
 813         FS_Printf(f, "\n");
 814         FS_Printf(f, "However, NEVER share the accompanying SECRET ID file called\n");
 815         FS_Printf(f, "key_%d.d0si%s, as doing so would compromise security!\n", i, sessionid.string);
 816         FS_Close(f);
 817
 818         return true;
 819 }
 820
 821 static void Crypto_BuildIdString(void)
 822 {
 823         int i;
 824         char vabuf[1024];
 825
 826         crypto_idstring = NULL;
 827         dpsnprintf(crypto_idstring_buf, sizeof(crypto_idstring_buf), "%d", d0_rijndael_dll ? crypto_aeslevel.integer : 0);
 828         for (i = 0; i < MAX_PUBKEYS; ++i)
 829                 if (pubkeys[i])
 830                         strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s%s", pubkeys_priv_fp64[i], pubkeys_havesig[i] ? "" : "~", pubkeys_fp64[i]), sizeof(crypto_idstring_buf));
 831         crypto_idstring = crypto_idstring_buf;
 832 }
 833
 834 void Crypto_LoadKeys(void)
 835 {
 836         char buf[8192];
 837         size_t len, len2;
 838         int i;
 839         char vabuf[1024];
 840
 841         if(!d0_blind_id_dll) // don't if we can't
 842                 return;
 843
 844         if(crypto_idstring) // already loaded? then not
 845                 return;
 846
 847         Host_LockSession(); // we use the session ID here
 848
 849         // load keys
 850         // note: we are just a CLIENT
 851         // so we load:
 852         //   PUBLIC KEYS to accept (including modulus)
 853         //   PRIVATE KEY of user
 854
 855         for(i = 0; i < MAX_PUBKEYS; ++i)
 856         {
 857                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 858                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 859                 pubkeys_havepriv[i] = false;
 860                 pubkeys_havesig[i] = false;
 861                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0pk", i), buf, sizeof(buf), false);
 862                 if((pubkeys[i] = Crypto_ReadPublicKey(buf, len)))
 863                 {
 864                         len2 = FP64_SIZE;
 865                         if(qd0_blind_id_fingerprint64_public_key(pubkeys[i], pubkeys_fp64[i], &len2)) // keeps final NUL
 866                         {
 867                                 Con_Printf("Loaded public key key_%d.d0pk (fingerprint: %s)\n", i, pubkeys_fp64[i]);
 868                                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0si%s", i, sessionid.string), buf, sizeof(buf), true);
 869                                 if(len)
 870                                 {
 871                                         if(Crypto_AddPrivateKey(pubkeys[i], buf, len))
 872                                         {
 873                                                 len2 = FP64_SIZE;
 874                                                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[i], pubkeys_priv_fp64[i], &len2)) // keeps final NUL
 875                                                 {
 876                                                         D0_BOOL status = 0;
 877
 878                                                         Con_Printf("Loaded private ID key_%d.d0si%s for key_%d.d0pk (public key fingerprint: %s)\n", i, sessionid.string, i, pubkeys_priv_fp64[i]);
 879
 880                                                         // verify the key we just loaded (just in case)
 881                                                         if(qd0_blind_id_verify_private_id(pubkeys[i]) && qd0_blind_id_verify_public_id(pubkeys[i], &status))
 882                                                         {
 883                                                                 pubkeys_havepriv[i] = true;
 884                                                                 pubkeys_havesig[i] = status;
 885
 886                                                                 // verify the key we just got (just in case)
 887                                                                 if(!status)
 888                                                                         Con_Printf("NOTE: this ID has not yet been signed!\n");
 889
 890                                                                 Crypto_SavePubKeyTextFile(i);
 891                                                         }
 892                                                         else
 893                                                         {
 894                                                                 Con_Printf("d0_blind_id_verify_private_id failed, this is not a valid key!\n");
 895                                                                 qd0_blind_id_free(pubkeys[i]);
 896                                                                 pubkeys[i] = NULL;
 897                                                         }
 898                                                 }
 899                                                 else
 900                                                 {
 901                                                         Con_Printf("d0_blind_id_fingerprint64_public_id failed\n");
 902                                                         qd0_blind_id_free(pubkeys[i]);
 903                                                         pubkeys[i] = NULL;
 904                                                 }
 905                                         }
 906                                 }
 907                         }
 908                         else
 909                         {
 910                                 // can't really happen
 911                                 qd0_blind_id_free(pubkeys[i]);
 912                                 pubkeys[i] = NULL;
 913                         }
 914                 }
 915         }
 916
 917         keygen_i = -1;
 918         Crypto_BuildIdString();
 919         Crypto_BuildChallengeAppend();
 920
 921         // find a good prefix length for all the keys we know (yes, algorithm is not perfect yet, may yield too long prefix length)
 922         crypto_keyfp_recommended_length = 0;
 923         memset(buf+256, 0, MAX_PUBKEYS + MAX_PUBKEYS);
 924         while(crypto_keyfp_recommended_length < FP64_SIZE)
 925         {
 926                 memset(buf, 0, 256);
 927                 for(i = 0; i < MAX_PUBKEYS; ++i)
 928                         if(pubkeys[i])
 929                         {
 930                                 if(!buf[256 + i])
 931                                         ++buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]];
 932                                 if(pubkeys_havepriv[i])
 933                                         if(!buf[256 + MAX_PUBKEYS + i])
 934                                                 ++buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]];
 935                         }
 936                 for(i = 0; i < MAX_PUBKEYS; ++i)
 937                         if(pubkeys[i])
 938                         {
 939                                 if(!buf[256 + i])
 940                                         if(buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]] < 2)
 941                                                 buf[256 + i] = 1;
 942                                 if(pubkeys_havepriv[i])
 943                                         if(!buf[256 + MAX_PUBKEYS + i])
 944                                                 if(buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]] < 2)
 945                                                         buf[256 + MAX_PUBKEYS + i] = 1;
 946                         }
 947                 ++crypto_keyfp_recommended_length;
 948                 for(i = 0; i < MAX_PUBKEYS; ++i)
 949                         if(pubkeys[i])
 950                         {
 951                                 if(!buf[256 + i])
 952                                         break;
 953                                 if(pubkeys_havepriv[i])
 954                                         if(!buf[256 + MAX_PUBKEYS + i])
 955                                                 break;
 956                         }
 957                 if(i >= MAX_PUBKEYS)
 958                         break;
 959         }
 960         if(crypto_keyfp_recommended_length < 7)
 961                 crypto_keyfp_recommended_length = 7;
 962 }
 963
 964 static void Crypto_UnloadKeys(void)
 965 {
 966         int i;
 967
 968         keygen_i = -1;
 969         for(i = 0; i < MAX_PUBKEYS; ++i)
 970         {
 971                 if(pubkeys[i])
 972                         qd0_blind_id_free(pubkeys[i]);
 973                 pubkeys[i] = NULL;
 974                 pubkeys_havepriv[i] = false;
 975                 pubkeys_havesig[i] = false;
 976                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 977                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 978                 challenge_append_length = 0;
 979         }
 980         crypto_idstring = NULL;
 981 }
 982
 983 static mempool_t *cryptomempool;
 984
 985 #ifdef __cplusplus
 986 extern "C"
 987 {
 988 #endif
 989 static void *Crypto_d0_malloc(size_t len)
 990 {
 991         return Mem_Alloc(cryptomempool, len);
 992 }
 993
 994 static void Crypto_d0_free(void *p)
 995 {
 996         Mem_Free(p);
 997 }
 998
 999 static void *Crypto_d0_createmutex(void)
1000 {
1001         return Thread_CreateMutex();
1002 }
1003
1004 static void Crypto_d0_destroymutex(void *m)
1005 {
1006         Thread_DestroyMutex(m);
1007 }
1008
1009 static int Crypto_d0_lockmutex(void *m)
1010 {
1011         return Thread_LockMutex(m);
1012 }
1013
1014 static int Crypto_d0_unlockmutex(void *m)
1015 {
1016         return Thread_UnlockMutex(m);
1017 }
1018 #ifdef __cplusplus
1019 }
1020 #endif
1021
1022 void Crypto_Shutdown(void)
1023 {
1024         crypto_t *crypto;
1025         int i;
1026
1027         Crypto_Rijndael_CloseLibrary();
1028
1029         if(d0_blind_id_dll)
1030         {
1031                 // free memory
1032                 for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
1033                 {
1034                         crypto = &cryptoconnects[i].crypto;
1035                         CLEAR_CDATA;
1036                 }
1037                 memset(cryptoconnects, 0, sizeof(cryptoconnects));
1038                 crypto = &cls.crypto;
1039                 CLEAR_CDATA;
1040
1041                 Crypto_UnloadKeys();
1042
1043                 qd0_blind_id_SHUTDOWN();
1044
1045                 Crypto_CloseLibrary();
1046         }
1047
1048         Mem_FreePool(&cryptomempool);
1049 }
1050
1051 void Crypto_Init(void)
1052 {
1053         cryptomempool = Mem_AllocPool("crypto", 0, NULL);
1054
1055         if(!Crypto_OpenLibrary())
1056                 return;
1057
1058         qd0_blind_id_setmallocfuncs(Crypto_d0_malloc, Crypto_d0_free);
1059         if (Thread_HasThreads())
1060                 qd0_blind_id_setmutexfuncs(Crypto_d0_createmutex, Crypto_d0_destroymutex, Crypto_d0_lockmutex, Crypto_d0_unlockmutex);
1061
1062         if(!qd0_blind_id_INITIALIZE())
1063         {
1064                 Crypto_Rijndael_CloseLibrary();
1065                 Crypto_CloseLibrary();
1066                 Con_Printf("libd0_blind_id initialization FAILED, cryptography support has been disabled\n");
1067                 return;
1068         }
1069
1070         (void) Crypto_Rijndael_OpenLibrary(); // if this fails, it's uncritical
1071
1072         Crypto_InitHostKeys();
1073 }
1074 // end
1075
1076 qboolean Crypto_Available(void)
1077 {
1078         if(!d0_blind_id_dll)
1079                 return false;
1080         return true;
1081 }
1082
1083 // keygen code
1084 static void Crypto_KeyGen_Finished(int code, size_t length_received, unsigned char *buffer, void *cbdata)
1085 {
1086         const char *p[1];
1087         size_t l[1];
1088         static char buf[8192];
1089         static char buf2[8192];
1090         size_t buf2size;
1091         qfile_t *f = NULL;
1092         D0_BOOL status;
1093         char vabuf[1024];
1094
1095         SV_LockThreadMutex();
1096
1097         if(!d0_blind_id_dll)
1098         {
1099                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1100                 keygen_i = -1;
1101                 SV_UnlockThreadMutex();
1102                 return;
1103         }
1104
1105         if(keygen_i < 0)
1106         {
1107                 Con_Printf("Unexpected response from keygen server:\n");
1108                 Com_HexDumpToConsole(buffer, (int)length_received);
1109                 SV_UnlockThreadMutex();
1110                 return;
1111         }
1112         if(keygen_i >= MAX_PUBKEYS || !pubkeys[keygen_i])
1113         {
1114                 Con_Printf("overflow of keygen_i\n");
1115                 keygen_i = -1;
1116                 SV_UnlockThreadMutex();
1117                 return;
1118         }
1119         if(!Crypto_ParsePack((const char *) buffer, length_received, FOURCC_D0IR, p, l, 1))
1120         {
1121                 if(length_received >= 5 && Crypto_LittleLong((const char *) buffer) == FOURCC_D0ER)
1122                 {
1123                         Con_Printf("Error response from keygen server: %.*s\n", (int)(length_received - 5), buffer + 5);
1124                 }
1125                 else
1126                 {
1127                         Con_Printf("Invalid response from keygen server:\n");
1128                         Com_HexDumpToConsole(buffer, (int)length_received);
1129                 }
1130                 keygen_i = -1;
1131                 SV_UnlockThreadMutex();
1132                 return;
1133         }
1134         if(!qd0_blind_id_finish_private_id_request(pubkeys[keygen_i], p[0], l[0]))
1135         {
1136                 Con_Printf("d0_blind_id_finish_private_id_request failed\n");
1137                 keygen_i = -1;
1138                 SV_UnlockThreadMutex();
1139                 return;
1140         }
1141
1142         // verify the key we just got (just in case)
1143         if(!qd0_blind_id_verify_public_id(pubkeys[keygen_i], &status) || !status)
1144         {
1145                 Con_Printf("d0_blind_id_verify_public_id failed\n");
1146                 keygen_i = -1;
1147                 SV_UnlockThreadMutex();
1148                 return;
1149         }
1150
1151         // we have a valid key now!
1152         // make the rest of crypto.c know that
1153         Con_Printf("Received signature for private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1154         pubkeys_havesig[keygen_i] = true;
1155
1156         // write the key to disk
1157         p[0] = buf;
1158         l[0] = sizeof(buf);
1159         if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1160         {
1161                 Con_Printf("d0_blind_id_write_private_id failed\n");
1162                 keygen_i = -1;
1163                 SV_UnlockThreadMutex();
1164                 return;
1165         }
1166         if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1167         {
1168                 Con_Printf("Crypto_UnParsePack failed\n");
1169                 keygen_i = -1;
1170                 SV_UnlockThreadMutex();
1171                 return;
1172         }
1173
1174         FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1175         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1176         if(!f)
1177         {
1178                 Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1179                 keygen_i = -1;
1180                 SV_UnlockThreadMutex();
1181                 return;
1182         }
1183         FS_Write(f, buf2, buf2size);
1184         FS_Close(f);
1185
1186         Crypto_SavePubKeyTextFile(keygen_i);
1187
1188         Con_Printf("Saved to key_%d.d0si%s\n", keygen_i, sessionid.string);
1189
1190         Crypto_BuildIdString();
1191
1192         keygen_i = -1;
1193         SV_UnlockThreadMutex();
1194 }
1195
1196 static void Crypto_KeyGen_f(void)
1197 {
1198         int i;
1199         const char *p[1];
1200         size_t l[1];
1201         static char buf[8192];
1202         static char buf2[8192];
1203         size_t buf2size;
1204         size_t buf2l, buf2pos;
1205         char vabuf[1024];
1206         size_t len2;
1207         qfile_t *f = NULL;
1208
1209         if(!d0_blind_id_dll)
1210         {
1211                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1212                 return;
1213         }
1214         if(Cmd_Argc() != 3)
1215         {
1216                 Con_Printf("usage:\n%s id url\n", Cmd_Argv(0));
1217                 return;
1218         }
1219         SV_LockThreadMutex();
1220         Crypto_LoadKeys();
1221         i = atoi(Cmd_Argv(1));
1222         if(!pubkeys[i])
1223         {
1224                 Con_Printf("there is no public key %d\n", i);
1225                 SV_UnlockThreadMutex();
1226                 return;
1227         }
1228         if(keygen_i >= 0)
1229         {
1230                 Con_Printf("there is already a keygen run on the way\n");
1231                 SV_UnlockThreadMutex();
1232                 return;
1233         }
1234         keygen_i = i;
1235
1236         // how to START the keygenning...
1237         if(pubkeys_havepriv[keygen_i])
1238         {
1239                 if(pubkeys_havesig[keygen_i])
1240                 {
1241                         Con_Printf("there is already a signed private key for %d\n", i);
1242                         keygen_i = -1;
1243                         SV_UnlockThreadMutex();
1244                         return;
1245                 }
1246                 // if we get here, we only need a signature, no new keygen run needed
1247                 Con_Printf("Only need a signature for an existing key...\n");
1248         }
1249         else
1250         {
1251                 // we also need a new ID itself
1252                 if(!qd0_blind_id_generate_private_id_start(pubkeys[keygen_i]))
1253                 {
1254                         Con_Printf("d0_blind_id_start failed\n");
1255                         keygen_i = -1;
1256                         SV_UnlockThreadMutex();
1257                         return;
1258                 }
1259                 // verify the key we just got (just in case)
1260                 if(!qd0_blind_id_verify_private_id(pubkeys[keygen_i]))
1261                 {
1262                         Con_Printf("d0_blind_id_verify_private_id failed\n");
1263                         keygen_i = -1;
1264                         SV_UnlockThreadMutex();
1265                         return;
1266                 }
1267                 // we have a valid key now!
1268                 // make the rest of crypto.c know that
1269                 len2 = FP64_SIZE;
1270                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[keygen_i], pubkeys_priv_fp64[keygen_i], &len2)) // keeps final NUL
1271                 {
1272                         Con_Printf("Generated private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1273                         pubkeys_havepriv[keygen_i] = true;
1274                         strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[keygen_i], pubkeys_fp64[keygen_i]), sizeof(crypto_idstring_buf));
1275                         crypto_idstring = crypto_idstring_buf;
1276                         Crypto_BuildChallengeAppend();
1277                 }
1278                 // write the key to disk
1279                 p[0] = buf;
1280                 l[0] = sizeof(buf);
1281                 if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1282                 {
1283                         Con_Printf("d0_blind_id_write_private_id failed\n");
1284                         keygen_i = -1;
1285                         SV_UnlockThreadMutex();
1286                         return;
1287                 }
1288                 if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1289                 {
1290                         Con_Printf("Crypto_UnParsePack failed\n");
1291                         keygen_i = -1;
1292                         SV_UnlockThreadMutex();
1293                         return;
1294                 }
1295
1296                 FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1297                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1298                 if(!f)
1299                 {
1300                         Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1301                         keygen_i = -1;
1302                         SV_UnlockThreadMutex();
1303                         return;
1304                 }
1305                 FS_Write(f, buf2, buf2size);
1306                 FS_Close(f);
1307
1308                 Crypto_SavePubKeyTextFile(keygen_i);
1309
1310                 Con_Printf("Saved unsigned key to key_%d.d0si%s\n", keygen_i, sessionid.string);
1311         }
1312         p[0] = buf;
1313         l[0] = sizeof(buf);
1314         if(!qd0_blind_id_generate_private_id_request(pubkeys[keygen_i], buf, &l[0]))
1315         {
1316                 Con_Printf("d0_blind_id_generate_private_id_request failed\n");
1317                 keygen_i = -1;
1318                 SV_UnlockThreadMutex();
1319                 return;
1320         }
1321         buf2pos = strlen(Cmd_Argv(2));
1322         memcpy(buf2, Cmd_Argv(2), buf2pos);
1323         if(!(buf2l = Crypto_UnParsePack(buf2 + buf2pos, sizeof(buf2) - buf2pos - 1, FOURCC_D0IQ, p, l, 1)))
1324         {
1325                 Con_Printf("Crypto_UnParsePack failed\n");
1326                 keygen_i = -1;
1327                 SV_UnlockThreadMutex();
1328                 return;
1329         }
1330         if(!(buf2l = base64_encode((unsigned char *) (buf2 + buf2pos), buf2l, sizeof(buf2) - buf2pos - 1)))
1331         {
1332                 Con_Printf("base64_encode failed\n");
1333                 keygen_i = -1;
1334                 SV_UnlockThreadMutex();
1335                 return;
1336         }
1337         buf2l += buf2pos;
1338         buf2[buf2l] = 0;
1339         if(!Curl_Begin_ToMemory(buf2, 0, (unsigned char *) keygen_buf, sizeof(keygen_buf), Crypto_KeyGen_Finished, NULL))
1340         {
1341                 Con_Printf("curl failed\n");
1342                 keygen_i = -1;
1343                 SV_UnlockThreadMutex();
1344                 return;
1345         }
1346         Con_Printf("Signature generation in progress...\n");
1347         SV_UnlockThreadMutex();
1348 }
1349 // end
1350
1351 // console commands
1352 static void Crypto_Reload_f(void)
1353 {
1354         Crypto_ClearHostKeys();
1355         Crypto_UnloadKeys();
1356         Crypto_LoadKeys();
1357 }
1358
1359 static void Crypto_Keys_f(void)
1360 {
1361         int i;
1362         if(!d0_blind_id_dll)
1363         {
1364                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1365                 return;
1366         }
1367         for(i = 0; i < MAX_PUBKEYS; ++i)
1368         {
1369                 if(pubkeys[i])
1370                 {
1371                         Con_Printf("%2d: public key key_%d.d0pk (fingerprint: %s)\n", i, i, pubkeys_fp64[i]);
1372                         if(pubkeys_havepriv[i])
1373                         {
1374                                 Con_Printf("    private ID key_%d.d0si%s (public key fingerprint: %s)\n", i, sessionid.string, pubkeys_priv_fp64[i]);
1375                                 if(!pubkeys_havesig[i])
1376                                         Con_Printf("    NOTE: this ID has not yet been signed!\n");
1377                         }
1378                 }
1379         }
1380 }
1381
1382 static void Crypto_HostKeys_f(void)
1383 {
1384         int i;
1385         crypto_storedhostkey_t *hk;
1386         char buf[128];
1387
1388         if(!d0_blind_id_dll)
1389         {
1390                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1391                 return;
1392         }
1393         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
1394         {
1395                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hk->next)
1396                 {
1397                         LHNETADDRESS_ToString(&hk->addr, buf, sizeof(buf), 1);
1398                         Con_Printf("%d %s@%.*s %s\n",
1399                                         hk->aeslevel,
1400                                         hk->idfp,
1401                                         crypto_keyfp_recommended_length, pubkeys_fp64[hk->keyid],
1402                                         buf);
1403                 }
1404         }
1405 }
1406
1407 static void Crypto_HostKey_Clear_f(void)
1408 {
1409         lhnetaddress_t addr;
1410         int i;
1411
1412         if(!d0_blind_id_dll)
1413         {
1414                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1415                 return;
1416         }
1417
1418         for(i = 1; i < Cmd_Argc(); ++i)
1419         {
1420                 LHNETADDRESS_FromString(&addr, Cmd_Argv(i), 26000);
1421                 if(Crypto_ClearHostKey(&addr))
1422                 {
1423                         Con_Printf("cleared host key for %s\n", Cmd_Argv(i));
1424                 }
1425         }
1426 }
1427
1428 void Crypto_Init_Commands(void)
1429 {
1430         if(d0_blind_id_dll)
1431         {
1432                 Cmd_AddCommand("crypto_reload", Crypto_Reload_f, "reloads cryptographic keys");
1433                 Cmd_AddCommand("crypto_keygen", Crypto_KeyGen_f, "generates and saves a cryptographic key");
1434                 Cmd_AddCommand("crypto_keys", Crypto_Keys_f, "lists the loaded keys");
1435                 Cmd_AddCommand("crypto_hostkeys", Crypto_HostKeys_f, "lists the cached host keys");
1436                 Cmd_AddCommand("crypto_hostkey_clear", Crypto_HostKey_Clear_f, "clears a cached host key");
1437                 Cvar_RegisterVariable(&crypto_developer);
1438                 if(d0_rijndael_dll)
1439                         Cvar_RegisterVariable(&crypto_aeslevel);
1440                 else
1441                         crypto_aeslevel.integer = 0; // make sure
1442                 Cvar_RegisterVariable(&crypto_servercpupercent);
1443                 Cvar_RegisterVariable(&crypto_servercpumaxtime);
1444                 Cvar_RegisterVariable(&crypto_servercpudebug);
1445         }
1446 }
1447 // end
1448
1449 // AES encryption
1450 static void aescpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1451 {
1452         const unsigned char *xorpos = iv;
1453         unsigned char xorbuf[16];
1454         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1455         size_t i;
1456         qd0_rijndael_setup_encrypt(rk, key, DHKEY_SIZE * 8);
1457         while(len > 16)
1458         {
1459                 for(i = 0; i < 16; ++i)
1460                         xorbuf[i] = src[i] ^ xorpos[i];
1461                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1462                 xorpos = dst;
1463                 len -= 16;
1464                 src += 16;
1465                 dst += 16;
1466         }
1467         if(len > 0)
1468         {
1469                 for(i = 0; i < len; ++i)
1470                         xorbuf[i] = src[i] ^ xorpos[i];
1471                 for(; i < 16; ++i)
1472                         xorbuf[i] = xorpos[i];
1473                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1474         }
1475 }
1476 static void seacpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1477 {
1478         const unsigned char *xorpos = iv;
1479         unsigned char xorbuf[16];
1480         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1481         size_t i;
1482         qd0_rijndael_setup_decrypt(rk, key, DHKEY_SIZE * 8);
1483         while(len > 16)
1484         {
1485                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1486                 for(i = 0; i < 16; ++i)
1487                         dst[i] = xorbuf[i] ^ xorpos[i];
1488                 xorpos = src;
1489                 len -= 16;
1490                 src += 16;
1491                 dst += 16;
1492         }
1493         if(len > 0)
1494         {
1495                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1496                 for(i = 0; i < len; ++i)
1497                         dst[i] = xorbuf[i] ^ xorpos[i];
1498         }
1499 }
1500
1501 // NOTE: we MUST avoid the following begins of the packet:
1502 //   1. 0xFF, 0xFF, 0xFF, 0xFF
1503 //   2. 0x80, 0x00, length/256, length%256
1504 // this luckily does NOT affect AES mode, where the first byte always is in the range from 0x00 to 0x0F
1505 const void *Crypto_EncryptPacket(crypto_t *crypto, const void *data_src, size_t len_src, void *data_dst, size_t *len_dst, size_t len)
1506 {
1507         unsigned char h[32];
1508         int i;
1509         if(crypto->authenticated)
1510         {
1511                 if(crypto->use_aes)
1512                 {
1513                         // AES packet = 1 byte length overhead, 15 bytes from HMAC-SHA-256, data, 0..15 bytes padding
1514                         // 15 bytes HMAC-SHA-256 (112bit) suffice as the attacker can't do more than forge a random-looking packet
1515                         // HMAC is needed to not leak information about packet content
1516                         if(developer_networking.integer)
1517                         {
1518                                 Con_Print("To be encrypted:\n");
1519                                 Com_HexDumpToConsole((const unsigned char *) data_src, (int)len_src);
1520                         }
1521                         if(len_src + 32 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, (int)len_src, crypto->dhkey, DHKEY_SIZE))
1522                         {
1523                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1524                                 return NULL;
1525                         }
1526                         *len_dst = ((len_src + 15) / 16) * 16 + 16; // add 16 for HMAC, then round to 16-size for AES
1527                         ((unsigned char *) data_dst)[0] = (unsigned char)(*len_dst - len_src);
1528                         memcpy(((unsigned char *) data_dst)+1, h, 15);
1529                         aescpy(crypto->dhkey, (const unsigned char *) data_dst, ((unsigned char *) data_dst) + 16, (const unsigned char *) data_src, len_src);
1530                         //                    IV                                dst                                src                               len
1531                 }
1532                 else
1533                 {
1534                         // HMAC packet = 16 bytes HMAC-SHA-256 (truncated to 128 bits), data
1535                         if(len_src + 16 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, (int)len_src, crypto->dhkey, DHKEY_SIZE))
1536                         {
1537                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1538                                 return NULL;
1539                         }
1540                         *len_dst = len_src + 16;
1541                         memcpy(data_dst, h, 16);
1542                         memcpy(((unsigned char *) data_dst) + 16, (unsigned char *) data_src, len_src);
1543
1544                         // handle the "avoid" conditions:
1545                         i = BuffBigLong((unsigned char *) data_dst);
1546                         if(
1547                                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1548                                 ||
1549                                 (i == (int)0x80000000 + (int)*len_dst) // avoid NQ control packet
1550                         )
1551                                 *(unsigned char *)data_dst ^= 0x80; // this will ALWAYS fix it
1552                 }
1553                 return data_dst;
1554         }
1555         else
1556         {
1557                 *len_dst = len_src;
1558                 return data_src;
1559         }
1560 }
1561
1562 const void *Crypto_DecryptPacket(crypto_t *crypto, const void *data_src, size_t len_src, void *data_dst, size_t *len_dst, size_t len)
1563 {
1564         unsigned char h[32];
1565         int i;
1566
1567         // silently handle non-crypto packets
1568         i = BuffBigLong((unsigned char *) data_src);
1569         if(
1570                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1571                 ||
1572                 (i == (int)0x80000000 + (int)len_src) // avoid NQ control packet
1573         )
1574                 return NULL;
1575
1576         if(crypto->authenticated)
1577         {
1578                 if(crypto->use_aes)
1579                 {
1580                         if(len_src < 16 || ((len_src - 16) % 16))
1581                         {
1582                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1583                                 return NULL;
1584                         }
1585                         *len_dst = len_src - ((unsigned char *) data_src)[0];
1586                         if(len < *len_dst || *len_dst > len_src - 16)
1587                         {
1588                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1589                                 return NULL;
1590                         }
1591                         seacpy(crypto->dhkey, (unsigned char *) data_src, (unsigned char *) data_dst, ((const unsigned char *) data_src) + 16, *len_dst);
1592                         //                    IV                          dst                         src                                      len
1593                         if(!HMAC_SHA256_32BYTES(h, (const unsigned char *) data_dst, (int)*len_dst, crypto->dhkey, DHKEY_SIZE))
1594                         {
1595                                 Con_Printf("HMAC fail\n");
1596                                 return NULL;
1597                         }
1598                         if(memcmp(((const unsigned char *) data_src)+1, h, 15)) // ignore first byte, used for length
1599                         {
1600                                 Con_Printf("HMAC mismatch\n");
1601                                 return NULL;
1602                         }
1603                         if(developer_networking.integer)
1604                         {
1605                                 Con_Print("Decrypted:\n");
1606                                 Com_HexDumpToConsole((const unsigned char *) data_dst, (int)*len_dst);
1607                         }
1608                         return data_dst; // no need to copy
1609                 }
1610                 else
1611                 {
1612                         if(len_src < 16)
1613                         {
1614                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1615                                 return NULL;
1616                         }
1617                         *len_dst = len_src - 16;
1618                         if(len < *len_dst)
1619                         {
1620                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1621                                 return NULL;
1622                         }
1623                         //memcpy(data_dst, data_src + 16, *len_dst);
1624                         if(!HMAC_SHA256_32BYTES(h, ((const unsigned char *) data_src) + 16, (int)*len_dst, crypto->dhkey, DHKEY_SIZE))
1625                         {
1626                                 Con_Printf("HMAC fail\n");
1627                                 Com_HexDumpToConsole((const unsigned char *) data_src, (int)len_src);
1628                                 return NULL;
1629                         }
1630
1631                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1632                         {
1633                                 // undo the "avoid conditions"
1634                                 if(
1635                                                 (i == (int)0x7FFFFFFF) // avoided QW control packet
1636                                                 ||
1637                                                 (i == (int)0x00000000 + (int)len_src) // avoided NQ control packet
1638                                   )
1639                                 {
1640                                         // do the avoidance on the hash too
1641                                         h[0] ^= 0x80;
1642                                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1643                                         {
1644                                                 Con_Printf("HMAC mismatch\n");
1645                                                 Com_HexDumpToConsole((const unsigned char *) data_src, (int)len_src);
1646                                                 return NULL;
1647                                         }
1648                                 }
1649                                 else
1650                                 {
1651                                         Con_Printf("HMAC mismatch\n");
1652                                         Com_HexDumpToConsole((const unsigned char *) data_src, (int)len_src);
1653                                         return NULL;
1654                                 }
1655                         }
1656                         return ((const unsigned char *) data_src) + 16; // no need to copy, so data_dst is not used
1657                 }
1658         }
1659         else
1660         {
1661                 *len_dst = len_src;
1662                 return data_src;
1663         }
1664 }
1665 // end
1666
1667 const char *Crypto_GetInfoResponseDataString(void)
1668 {
1669         crypto_idstring_buf[0] = '0' + crypto_aeslevel.integer;
1670         return crypto_idstring;
1671 }
1672
1673 // network protocol
1674 qboolean Crypto_ServerAppendToChallenge(const char *data_in, size_t len_in, char *data_out, size_t *len_out, size_t maxlen_out)
1675 {
1676         // cheap op, all is precomputed
1677         if(!d0_blind_id_dll)
1678                 return false; // no support
1679         // append challenge
1680         if(maxlen_out <= *len_out + challenge_append_length)
1681                 return false;
1682         memcpy(data_out + *len_out, challenge_append, challenge_append_length);
1683         *len_out += challenge_append_length;
1684         return false;
1685 }
1686
1687 static int Crypto_ServerError(char *data_out, size_t *len_out, const char *msg, const char *msg_client)
1688 {
1689         if(!msg_client)
1690                 msg_client = msg;
1691         Con_DPrintf("rejecting client: %s\n", msg);
1692         if(*msg_client)
1693                 dpsnprintf(data_out, *len_out, "reject %s", msg_client);
1694         *len_out = strlen(data_out);
1695         return CRYPTO_DISCARD;
1696 }
1697
1698 static int Crypto_SoftServerError(char *data_out, size_t *len_out, const char *msg)
1699 {
1700         *len_out = 0;
1701         Con_DPrintf("%s\n", msg);
1702         return CRYPTO_DISCARD;
1703 }
1704
1705 static int Crypto_ServerParsePacket_Internal(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1706 {
1707         // if "connect": reject if in the middle of crypto handshake
1708         crypto_t *crypto = NULL;
1709         char *data_out_p = data_out;
1710         const char *string = data_in;
1711         int aeslevel;
1712         D0_BOOL aes;
1713         D0_BOOL status;
1714         char infostringvalue[MAX_INPUTLINE];
1715         char vabuf[1024];
1716
1717         if(!d0_blind_id_dll)
1718                 return CRYPTO_NOMATCH; // no support
1719
1720         if (len_in > 8 && !memcmp(string, "connect\\", 8) && d0_rijndael_dll && crypto_aeslevel.integer >= 3)
1721         {
1722                 const char *s;
1723                 int i;
1724                 // sorry, we have to verify the challenge here to not reflect network spam
1725
1726                 if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1727                         return CRYPTO_NOMATCH; // will be later accepted if encryption was set up
1728                 // validate the challenge
1729                 for (i = 0;i < MAX_CHALLENGES;i++)
1730                         if(challenges[i].time > 0)
1731                                 if (!LHNETADDRESS_Compare(peeraddress, &challenges[i].address) && !strcmp(challenges[i].string, s))
1732                                         break;
1733                 // if the challenge is not recognized, drop the packet
1734                 if (i == MAX_CHALLENGES) // challenge mismatch is silent
1735                         return Crypto_SoftServerError(data_out, len_out, "missing challenge in connect");
1736
1737                 crypto = Crypto_ServerFindInstance(peeraddress, false);
1738                 if(!crypto || !crypto->authenticated)
1739                         return Crypto_ServerError(data_out, len_out, "This server requires authentication and encryption to be supported by your client", NULL);
1740         }
1741         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && ((LHNETADDRESS_GetAddressType(peeraddress) == LHNETADDRESSTYPE_LOOP) || sv_public.integer > -3))
1742         {
1743                 const char *cnt, *s, *p;
1744                 int id;
1745                 int clientid = -1, serverid = -1;
1746                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
1747                 id = (cnt ? atoi(cnt) : -1);
1748                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1749                 if(!cnt)
1750                         return Crypto_SoftServerError(data_out, len_out, "missing cnt in d0pk");
1751                 GetUntilNul(&data_in, &len_in);
1752                 if(!data_in)
1753                         return Crypto_SoftServerError(data_out, len_out, "missing appended data in d0pk");
1754                 if(!strcmp(cnt, "0"))
1755                 {
1756                         int i;
1757                         if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1758                                 return Crypto_SoftServerError(data_out, len_out, "missing challenge in d0pk\\0");
1759                         // validate the challenge
1760                         for (i = 0;i < MAX_CHALLENGES;i++)
1761                                 if(challenges[i].time > 0)
1762                                         if (!LHNETADDRESS_Compare(peeraddress, &challenges[i].address) && !strcmp(challenges[i].string, s))
1763                                                 break;
1764                         // if the challenge is not recognized, drop the packet
1765                         if (i == MAX_CHALLENGES)
1766                                 return Crypto_SoftServerError(data_out, len_out, "invalid challenge in d0pk\\0");
1767
1768                         if (!(s = InfoString_GetValue(string + 4, "aeslevel", infostringvalue, sizeof(infostringvalue))))
1769                                 aeslevel = 0; // not supported
1770                         else
1771                                 aeslevel = bound(0, atoi(s), 3);
1772                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
1773                         {
1774                                 default: // dummy, never happens, but to make gcc happy...
1775                                 case 0:
1776                                         if(aeslevel >= 3)
1777                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
1778                                         aes = false;
1779                                         break;
1780                                 case 1:
1781                                         aes = (aeslevel >= 2);
1782                                         break;
1783                                 case 2:
1784                                         aes = (aeslevel >= 1);
1785                                         break;
1786                                 case 3:
1787                                         if(aeslevel <= 0)
1788                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be supported (crypto_aeslevel >= 1, and d0_rijndael library must be present)", NULL);
1789                                         aes = true;
1790                                         break;
1791                         }
1792
1793                         p = GetUntilNul(&data_in, &len_in);
1794                         if(p && *p)
1795                         {
1796                                 // Find the highest numbered matching key for p.
1797                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1798                                 {
1799                                         if(pubkeys[i])
1800                                                 if(!strcmp(p, pubkeys_fp64[i]))
1801                                                         if(pubkeys_havepriv[i])
1802                                                                 serverid = i;
1803                                 }
1804                                 if(serverid < 0)
1805                                         return Crypto_ServerError(data_out, len_out, "Invalid server key", NULL);
1806                         }
1807                         p = GetUntilNul(&data_in, &len_in);
1808                         if(p && *p)
1809                         {
1810                                 // Find the highest numbered matching key for p.
1811                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1812                                 {
1813                                         if(pubkeys[i])
1814                                                 if(!strcmp(p, pubkeys_fp64[i]))
1815                                                         clientid = i;
1816                                 }
1817                                 if(clientid < 0)
1818                                         return Crypto_ServerError(data_out, len_out, "Invalid client key", NULL);
1819                         }
1820
1821                         crypto = Crypto_ServerFindInstance(peeraddress, true);
1822                         if(!crypto)
1823                                 return Crypto_ServerError(data_out, len_out, "Could not create a crypto connect instance", NULL);
1824                         MAKE_CDATA;
1825                         CDATA->cdata_id = id;
1826                         CDATA->s = serverid;
1827                         CDATA->c = clientid;
1828                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
1829                         CDATA->challenge[0] = 0;
1830                         crypto->client_keyfp[0] = 0;
1831                         crypto->client_idfp[0] = 0;
1832                         crypto->server_keyfp[0] = 0;
1833                         crypto->server_idfp[0] = 0;
1834                         crypto->use_aes = aes != 0;
1835
1836                         if(CDATA->s >= 0)
1837                         {
1838                                 // I am the server, and my key is ok... so let's set server_keyfp and server_idfp
1839                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
1840                                 strlcpy(crypto->server_idfp, pubkeys_priv_fp64[CDATA->s], sizeof(crypto->server_idfp));
1841                                 crypto->server_issigned = pubkeys_havesig[CDATA->s];
1842
1843                                 if(!CDATA->id)
1844                                         CDATA->id = qd0_blind_id_new();
1845                                 if(!CDATA->id)
1846                                 {
1847                                         CLEAR_CDATA;
1848                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1849                                 }
1850                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
1851                                 {
1852                                         CLEAR_CDATA;
1853                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1854                                 }
1855                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\1\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1856                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
1857                                 {
1858                                         CLEAR_CDATA;
1859                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed", "Internal error");
1860                                 }
1861                                 CDATA->next_step = 2;
1862                                 data_out_p += *len_out;
1863                                 *len_out = data_out_p - data_out;
1864                                 return CRYPTO_DISCARD;
1865                         }
1866                         else if(CDATA->c >= 0)
1867                         {
1868                                 if(!CDATA->id)
1869                                         CDATA->id = qd0_blind_id_new();
1870                                 if(!CDATA->id)
1871                                 {
1872                                         CLEAR_CDATA;
1873                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1874                                 }
1875                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1876                                 {
1877                                         CLEAR_CDATA;
1878                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1879                                 }
1880                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1881                                 if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1882                                 {
1883                                         CLEAR_CDATA;
1884                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1885                                 }
1886                                 CDATA->next_step = 6;
1887                                 data_out_p += *len_out;
1888                                 *len_out = data_out_p - data_out;
1889                                 return CRYPTO_DISCARD;
1890                         }
1891                         else
1892                         {
1893                                 CLEAR_CDATA;
1894                                 return Crypto_ServerError(data_out, len_out, "Missing client and server key", NULL);
1895                         }
1896                 }
1897                 else if(!strcmp(cnt, "2"))
1898                 {
1899                         size_t fpbuflen;
1900                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1901                         if(!crypto)
1902                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1903                         if(id >= 0)
1904                                 if(CDATA->cdata_id != id)
1905                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1906                         if(CDATA->next_step != 2)
1907                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1908
1909                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\3\\id\\%d", CDATA->cdata_id));
1910                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
1911                         {
1912                                 CLEAR_CDATA;
1913                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed", "Internal error");
1914                         }
1915                         fpbuflen = DHKEY_SIZE;
1916                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
1917                         {
1918                                 CLEAR_CDATA;
1919                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1920                         }
1921                         if(CDATA->c >= 0)
1922                         {
1923                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1924                                 {
1925                                         CLEAR_CDATA;
1926                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1927                                 }
1928                                 CDATA->next_step = 4;
1929                         }
1930                         else
1931                         {
1932                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1933                                 crypto->authenticated = true;
1934                                 CDATA->next_step = 0;
1935                         }
1936                         data_out_p += *len_out;
1937                         *len_out = data_out_p - data_out;
1938                         return CRYPTO_DISCARD;
1939                 }
1940                 else if(!strcmp(cnt, "4"))
1941                 {
1942                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1943                         if(!crypto)
1944                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1945                         if(id >= 0)
1946                                 if(CDATA->cdata_id != id)
1947                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1948                         if(CDATA->next_step != 4)
1949                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1950                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d", CDATA->cdata_id));
1951                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1952                         {
1953                                 CLEAR_CDATA;
1954                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1955                         }
1956                         CDATA->next_step = 6;
1957                         data_out_p += *len_out;
1958                         *len_out = data_out_p - data_out;
1959                         return CRYPTO_DISCARD;
1960                 }
1961                 else if(!strcmp(cnt, "6"))
1962                 {
1963                         static char msgbuf[32];
1964                         size_t msgbuflen = sizeof(msgbuf);
1965                         size_t fpbuflen;
1966                         int i;
1967                         unsigned char dhkey[DHKEY_SIZE];
1968                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1969                         if(!crypto)
1970                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1971                         if(id >= 0)
1972                                 if(CDATA->cdata_id != id)
1973                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1974                         if(CDATA->next_step != 6)
1975                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1976
1977                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
1978                         {
1979                                 CLEAR_CDATA;
1980                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (authentication error)", "Authentication error");
1981                         }
1982                         strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
1983                         crypto->client_issigned = status;
1984
1985                         memset(crypto->client_idfp, 0, sizeof(crypto->client_idfp));
1986                         fpbuflen = FP64_SIZE;
1987                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->client_idfp, &fpbuflen))
1988                         {
1989                                 CLEAR_CDATA;
1990                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed", "Internal error");
1991                         }
1992                         fpbuflen = DHKEY_SIZE;
1993                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
1994                         {
1995                                 CLEAR_CDATA;
1996                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1997                         }
1998                         // XOR the two DH keys together to make one
1999                         for(i = 0; i < DHKEY_SIZE; ++i)
2000                                 crypto->dhkey[i] ^= dhkey[i];
2001
2002                         // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
2003                         crypto->authenticated = true;
2004                         CDATA->next_step = 0;
2005                         // send a challenge-less challenge
2006                         PutWithNul(&data_out_p, len_out, "challenge ");
2007                         *len_out = data_out_p - data_out;
2008                         --*len_out; // remove NUL terminator
2009                         return CRYPTO_MATCH;
2010                 }
2011                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
2012         }
2013         return CRYPTO_NOMATCH;
2014 }
2015
2016 int Crypto_ServerParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
2017 {
2018         int ret;
2019         double t = 0;
2020         static double complain_time = 0;
2021         const char *cnt;
2022         qboolean do_time = false;
2023         qboolean do_reject = false;
2024         char infostringvalue[MAX_INPUTLINE];
2025         if(crypto_servercpupercent.value > 0 || crypto_servercpumaxtime.value > 0)
2026                 if(len_in > 5 && !memcmp(data_in, "d0pk\\", 5))
2027                 {
2028                         do_time = true;
2029                         cnt = InfoString_GetValue(data_in + 4, "cnt", infostringvalue, sizeof(infostringvalue));
2030                         if(cnt)
2031                                 if(!strcmp(cnt, "0"))
2032                                         do_reject = true;
2033                 }
2034         if(do_time)
2035         {
2036                 // check if we may perform crypto...
2037                 if(crypto_servercpupercent.value > 0)
2038                 {
2039                         crypto_servercpu_accumulator += (realtime - crypto_servercpu_lastrealtime) * crypto_servercpupercent.value * 0.01;
2040                         if(crypto_servercpumaxtime.value)
2041                                 if(crypto_servercpu_accumulator > crypto_servercpumaxtime.value)
2042                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
2043                 }
2044                 else
2045                 {
2046                         if(crypto_servercpumaxtime.value > 0)
2047                                 if(realtime != crypto_servercpu_lastrealtime)
2048                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
2049                 }
2050                 crypto_servercpu_lastrealtime = realtime;
2051                 if(do_reject && crypto_servercpu_accumulator < 0)
2052                 {
2053                         if(realtime > complain_time + 5)
2054                                 Con_Printf("crypto: cannot perform requested crypto operations; denial service attack or crypto_servercpupercent/crypto_servercpumaxtime are too low\n");
2055                         *len_out = 0;
2056                         return CRYPTO_DISCARD;
2057                 }
2058                 t = Sys_DirtyTime();
2059         }
2060         ret = Crypto_ServerParsePacket_Internal(data_in, len_in, data_out, len_out, peeraddress);
2061         if(do_time)
2062         {
2063                 t = Sys_DirtyTime() - t;if (t < 0.0) t = 0.0; // dirtytime can step backwards
2064                 if(crypto_servercpudebug.integer)
2065                         Con_Printf("crypto: accumulator was %.1f ms, used %.1f ms for crypto, ", crypto_servercpu_accumulator * 1000, t * 1000);
2066                 crypto_servercpu_accumulator -= t;
2067                 if(crypto_servercpudebug.integer)
2068                         Con_Printf("is %.1f ms\n", crypto_servercpu_accumulator * 1000);
2069         }
2070         return ret;
2071 }
2072
2073 static int Crypto_ClientError(char *data_out, size_t *len_out, const char *msg)
2074 {
2075         dpsnprintf(data_out, *len_out, "reject %s", msg);
2076         *len_out = strlen(data_out);
2077         return CRYPTO_REPLACE;
2078 }
2079
2080 static int Crypto_SoftClientError(char *data_out, size_t *len_out, const char *msg)
2081 {
2082         *len_out = 0;
2083         Con_DPrintf("%s\n", msg);
2084         return CRYPTO_DISCARD;
2085 }
2086
2087 int Crypto_ClientParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
2088 {
2089         crypto_t *crypto = &cls.crypto;
2090         const char *string = data_in;
2091         const char *s;
2092         D0_BOOL aes;
2093         char *data_out_p = data_out;
2094         D0_BOOL status;
2095         char infostringvalue[MAX_INPUTLINE];
2096         char vabuf[1024];
2097
2098         if(!d0_blind_id_dll)
2099                 return CRYPTO_NOMATCH; // no support
2100
2101         // if "challenge": verify challenge, and discard message, send next crypto protocol message instead
2102         // otherwise, just handle actual protocol messages
2103
2104         if (len_in == 6 && !memcmp(string, "accept", 6) && cls.connect_trying && d0_rijndael_dll)
2105         {
2106                 int wantserverid = -1;
2107                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL, NULL);
2108                 if(!crypto || !crypto->authenticated) // we ALSO get here if we are using an encrypted connection, so let's rule this out
2109                 {
2110                         if(wantserverid >= 0)
2111                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2112                         if(crypto_aeslevel.integer >= 3)
2113                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2114                 }
2115                 return CRYPTO_NOMATCH;
2116         }
2117         else if (len_in >= 1 && string[0] == 'j' && cls.connect_trying && d0_rijndael_dll)
2118         {
2119                 int wantserverid = -1;
2120                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL, NULL);
2121                 //if(!crypto || !crypto->authenticated)
2122                 {
2123                         if(wantserverid >= 0)
2124                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2125                         if(crypto_aeslevel.integer >= 3)
2126                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2127                 }
2128                 return CRYPTO_NOMATCH;
2129         }
2130         else if (len_in >= 5 && BuffLittleLong((unsigned char *) string) == ((int)NETFLAG_CTL | (int)len_in))
2131         {
2132                 int wantserverid = -1;
2133
2134                 // these three are harmless
2135                 if((unsigned char) string[4] == CCREP_SERVER_INFO)
2136                         return CRYPTO_NOMATCH;
2137                 if((unsigned char) string[4] == CCREP_PLAYER_INFO)
2138                         return CRYPTO_NOMATCH;
2139                 if((unsigned char) string[4] == CCREP_RULE_INFO)
2140                         return CRYPTO_NOMATCH;
2141
2142                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL, NULL);
2143                 //if(!crypto || !crypto->authenticated)
2144                 {
2145                         if(wantserverid >= 0)
2146                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2147                         if(crypto_aeslevel.integer >= 3)
2148                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2149                 }
2150                 return CRYPTO_NOMATCH;
2151         }
2152         else if (len_in >= 13 && !memcmp(string, "infoResponse\x0A", 13))
2153         {
2154                 s = InfoString_GetValue(string + 13, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2155                 if(s)
2156                         Crypto_StoreHostKey(peeraddress, s, true);
2157                 return CRYPTO_NOMATCH;
2158         }
2159         else if (len_in >= 15 && !memcmp(string, "statusResponse\x0A", 15))
2160         {
2161                 char save = 0;
2162                 const char *p;
2163                 p = strchr(string + 15, '\n');
2164                 if(p)
2165                 {
2166                         save = *p;
2167                         * (char *) p = 0; // cut off the string there
2168                 }
2169                 s = InfoString_GetValue(string + 15, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2170                 if(s)
2171                         Crypto_StoreHostKey(peeraddress, s, true);
2172                 if(p)
2173                 {
2174                         * (char *) p = save;
2175                         // invoking those nasal demons again (do not run this on the DS9k)
2176                 }
2177                 return CRYPTO_NOMATCH;
2178         }
2179         else if(len_in > 10 && !memcmp(string, "challenge ", 10) && cls.connect_trying)
2180         {
2181                 const char *vlen_blind_id_ptr = NULL;
2182                 size_t len_blind_id_ptr = 0;
2183                 unsigned long k, v;
2184                 const char *challenge = data_in + 10;
2185                 const char *p;
2186                 int i;
2187                 int clientid = -1, serverid = -1, wantserverid = -1;
2188                 qboolean server_can_auth = true;
2189                 char wantserver_idfp[FP64_SIZE+1];
2190                 int wantserver_aeslevel = 0;
2191                 qboolean wantserver_issigned = false;
2192
2193                 // Must check the source IP here, if we want to prevent other servers' replies from falsely advancing the crypto state, preventing successful connect to the real server.
2194                 if (net_sourceaddresscheck.integer && LHNETADDRESS_Compare(peeraddress, &cls.connect_address))
2195                         return Crypto_SoftClientError(data_out, len_out, "challenge message from wrong server");
2196
2197                 // if we have a stored host key for the server, assume serverid to already be selected!
2198                 // (the loop will refuse to overwrite this one then)
2199                 wantserver_idfp[0] = 0;
2200                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, wantserver_idfp, sizeof(wantserver_idfp), &wantserver_aeslevel, &wantserver_issigned);
2201                 // requirement: wantserver_idfp is a full ID if wantserverid set
2202
2203                 // if we leave, we have to consider the connection
2204                 // unauthenticated; NOTE: this may be faked by a clever
2205                 // attacker to force an unauthenticated connection; so we have
2206                 // a safeguard check in place when encryption is required too
2207                 // in place, or when authentication is required by the server
2208                 crypto->authenticated = false;
2209
2210                 GetUntilNul(&data_in, &len_in);
2211                 if(!data_in)
2212                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present") :
2213                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)") :
2214                                 CRYPTO_NOMATCH;
2215
2216                 // FTEQW extension protocol
2217                 while(len_in >= 8)
2218                 {
2219                         k = Crypto_LittleLong(data_in);
2220                         v = Crypto_LittleLong(data_in + 4);
2221                         data_in += 8;
2222                         len_in -= 8;
2223                         switch(k)
2224                         {
2225                                 case PROTOCOL_VLEN:
2226                                         if(len_in >= 4 + v)
2227                                         {
2228                                                 k = Crypto_LittleLong(data_in);
2229                                                 data_in += 4;
2230                                                 len_in -= 4;
2231                                                 switch(k)
2232                                                 {
2233                                                         case PROTOCOL_D0_BLIND_ID:
2234                                                                 vlen_blind_id_ptr = data_in;
2235                                                                 len_blind_id_ptr = v;
2236                                                                 break;
2237                                                 }
2238                                                 data_in += v;
2239                                                 len_in -= v;
2240                                         }
2241                                         break;
2242                                 default:
2243                                         break;
2244                         }
2245                 }
2246
2247                 if(!vlen_blind_id_ptr)
2248                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though authentication is required") :
2249                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)") :
2250                                 CRYPTO_NOMATCH;
2251
2252                 data_in = vlen_blind_id_ptr;
2253                 len_in = len_blind_id_ptr;
2254
2255                 // parse fingerprints
2256                 //   once we found a fingerprint we can auth to (ANY), select it as clientfp
2257                 //   once we found a fingerprint in the first list that we know, select it as serverfp
2258
2259                 for(;;)
2260                 {
2261                         p = GetUntilNul(&data_in, &len_in);
2262                         if(!p)
2263                                 break;
2264                         if(!*p)
2265                         {
2266                                 if(!server_can_auth)
2267                                         break; // other protocol message may follow
2268                                 server_can_auth = false;
2269                                 if(clientid >= 0)
2270                                         break;
2271                                 continue;
2272                         }
2273                         // Find the highest numbered matching key for p.
2274                         for(i = 0; i < MAX_PUBKEYS; ++i)
2275                         {
2276                                 if(pubkeys[i])
2277                                 if(!strcmp(p, pubkeys_fp64[i]))
2278                                 {
2279                                         if(pubkeys_havepriv[i])
2280                                                 clientid = i;
2281                                         if(server_can_auth)
2282                                                 if(wantserverid < 0 || i == wantserverid)
2283                                                         serverid = i;
2284                                 }
2285                         }
2286                         // Not breaking, as higher keys in the list always have priority.
2287                 }
2288
2289                 // if stored host key is not found:
2290                 if(wantserverid >= 0 && serverid < 0)
2291                         return Crypto_ClientError(data_out, len_out, "Server CA does not match stored host key, refusing to connect");
2292
2293                 if(serverid >= 0 || clientid >= 0)
2294                 {
2295                         MAKE_CDATA;
2296                         CDATA->cdata_id = ++cdata_id;
2297                         CDATA->s = serverid;
2298                         CDATA->c = clientid;
2299                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
2300                         strlcpy(CDATA->challenge, challenge, sizeof(CDATA->challenge));
2301                         crypto->client_keyfp[0] = 0;
2302                         crypto->client_idfp[0] = 0;
2303                         crypto->server_keyfp[0] = 0;
2304                         crypto->server_idfp[0] = 0;
2305                         memcpy(CDATA->wantserver_idfp, wantserver_idfp, sizeof(crypto->server_idfp));
2306                         CDATA->wantserver_issigned = wantserver_issigned;
2307
2308                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2309                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
2310                         {
2311                                 default: // dummy, never happens, but to make gcc happy...
2312                                 case 0:
2313                                         if(wantserver_aeslevel >= 3)
2314                                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2315                                         CDATA->wantserver_aes = false;
2316                                         break;
2317                                 case 1:
2318                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 2);
2319                                         break;
2320                                 case 2:
2321                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 1);
2322                                         break;
2323                                 case 3:
2324                                         if(wantserver_aeslevel <= 0)
2325                                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be supported (crypto_aeslevel >= 1, and d0_rijndael library must be present)");
2326                                         CDATA->wantserver_aes = true;
2327                                         break;
2328                         }
2329
2330                         // build outgoing message
2331                         // append regular stuff
2332                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\0\\id\\%d\\aeslevel\\%d\\challenge\\%s", CDATA->cdata_id, d0_rijndael_dll ? crypto_aeslevel.integer : 0, challenge));
2333                         PutWithNul(&data_out_p, len_out, serverid >= 0 ? pubkeys_fp64[serverid] : "");
2334                         PutWithNul(&data_out_p, len_out, clientid >= 0 ? pubkeys_fp64[clientid] : "");
2335
2336                         if(clientid >= 0)
2337                         {
2338                                 // I am the client, and my key is ok... so let's set client_keyfp and client_idfp
2339                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
2340                                 strlcpy(crypto->client_idfp, pubkeys_priv_fp64[CDATA->c], sizeof(crypto->client_idfp));
2341                                 crypto->client_issigned = pubkeys_havesig[CDATA->c];
2342                         }
2343
2344                         if(serverid >= 0)
2345                         {
2346                                 if(!CDATA->id)
2347                                         CDATA->id = qd0_blind_id_new();
2348                                 if(!CDATA->id)
2349                                 {
2350                                         CLEAR_CDATA;
2351                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2352                                 }
2353                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
2354                                 {
2355                                         CLEAR_CDATA;
2356                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2357                                 }
2358                                 CDATA->next_step = 1;
2359                                 *len_out = data_out_p - data_out;
2360                         }
2361                         else // if(clientid >= 0) // guaranteed by condition one level outside
2362                         {
2363                                 // skip over server auth, perform client auth only
2364                                 if(!CDATA->id)
2365                                         CDATA->id = qd0_blind_id_new();
2366                                 if(!CDATA->id)
2367                                 {
2368                                         CLEAR_CDATA;
2369                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2370                                 }
2371                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2372                                 {
2373                                         CLEAR_CDATA;
2374                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2375                                 }
2376                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
2377                                 {
2378                                         CLEAR_CDATA;
2379                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2380                                 }
2381                                 CDATA->next_step = 5;
2382                                 data_out_p += *len_out;
2383                                 *len_out = data_out_p - data_out;
2384                         }
2385                         return CRYPTO_DISCARD;
2386                 }
2387                 else
2388                 {
2389                         if(wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2390                         if(wantserver_aeslevel >= 3)
2391                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption, but neither can authenticate to the other");
2392                         return (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)") :
2393                                 CRYPTO_NOMATCH;
2394                 }
2395         }
2396         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && cls.connect_trying)
2397         {
2398                 const char *cnt;
2399                 int id;
2400
2401                 // Must check the source IP here, if we want to prevent other servers' replies from falsely advancing the crypto state, preventing successful connect to the real server.
2402                 if (net_sourceaddresscheck.integer && LHNETADDRESS_Compare(peeraddress, &cls.connect_address))
2403                         return Crypto_SoftClientError(data_out, len_out, "d0pk\\ message from wrong server");
2404
2405                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
2406                 id = (cnt ? atoi(cnt) : -1);
2407                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
2408                 if(!cnt)
2409                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without cnt");
2410                 GetUntilNul(&data_in, &len_in);
2411                 if(!data_in)
2412                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without attachment");
2413
2414                 if(!strcmp(cnt, "1"))
2415                 {
2416                         if(id >= 0)
2417                                 if(CDATA->cdata_id != id)
2418                                         return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2419                         if(CDATA->next_step != 1)
2420                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2421
2422                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2423
2424                         if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2425                                 aes = atoi(s);
2426                         else
2427                                 aes = false;
2428                         // we CANNOT toggle the AES status any more!
2429                         // as the server already decided
2430                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2431                         if(!aes && CDATA->wantserver_aes)
2432                         {
2433                                 CLEAR_CDATA;
2434                                 return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2435                         }
2436                         if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2437                         {
2438                                 CLEAR_CDATA;
2439                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2440                         }
2441                         if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2442                         {
2443                                 CLEAR_CDATA;
2444                                 return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2445                         }
2446                         crypto->use_aes = aes != 0;
2447
2448                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\2\\id\\%d", CDATA->cdata_id));
2449                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
2450                         {
2451                                 CLEAR_CDATA;
2452                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed");
2453                         }
2454                         CDATA->next_step = 3;
2455                         data_out_p += *len_out;
2456                         *len_out = data_out_p - data_out;
2457                         return CRYPTO_DISCARD;
2458                 }
2459                 else if(!strcmp(cnt, "3"))
2460                 {
2461                         static char msgbuf[32];
2462                         size_t msgbuflen = sizeof(msgbuf);
2463                         size_t fpbuflen;
2464
2465                         if(id >= 0)
2466                                 if(CDATA->cdata_id != id)
2467                                         return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2468                         if(CDATA->next_step != 3)
2469                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2470
2471                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2472
2473                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
2474                         {
2475                                 CLEAR_CDATA;
2476                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (server authentication error)");
2477                         }
2478
2479                         strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
2480                         if (!status && CDATA->wantserver_issigned)
2481                         {
2482                                 CLEAR_CDATA;
2483                                 return Crypto_ClientError(data_out, len_out, "Stored host key requires a valid signature, but server did not provide any");
2484                         }
2485                         crypto->server_issigned = status;
2486
2487                         memset(crypto->server_idfp, 0, sizeof(crypto->server_idfp));
2488                         fpbuflen = FP64_SIZE;
2489                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->server_idfp, &fpbuflen))
2490                         {
2491                                 CLEAR_CDATA;
2492                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed");
2493                         }
2494                         if(CDATA->wantserver_idfp[0])
2495                         if(memcmp(CDATA->wantserver_idfp, crypto->server_idfp, sizeof(crypto->server_idfp)))
2496                         {
2497                                 CLEAR_CDATA;
2498                                 return Crypto_ClientError(data_out, len_out, "Server ID does not match stored host key, refusing to connect");
2499                         }
2500                         fpbuflen = DHKEY_SIZE;
2501                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
2502                         {
2503                                 CLEAR_CDATA;
2504                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2505                         }
2506
2507                         // cache the server key
2508                         Crypto_StoreHostKey(&cls.connect_address, va(vabuf, sizeof(vabuf), "%d %s@%s%s", crypto->use_aes ? 1 : 0, crypto->server_idfp, crypto->server_issigned ? "" : "~", pubkeys_fp64[CDATA->s]), false);
2509
2510                         if(CDATA->c >= 0)
2511                         {
2512                                 // client will auth next
2513                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\4\\id\\%d", CDATA->cdata_id));
2514                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2515                                 {
2516                                         CLEAR_CDATA;
2517                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2518                                 }
2519                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
2520                                 {
2521                                         CLEAR_CDATA;
2522                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2523                                 }
2524                                 CDATA->next_step = 5;
2525                                 data_out_p += *len_out;
2526                                 *len_out = data_out_p - data_out;
2527                                 return CRYPTO_DISCARD;
2528                         }
2529                         else
2530                         {
2531                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
2532                                 crypto->authenticated = true;
2533                                 CDATA->next_step = 0;
2534                                 // assume we got the empty challenge to finish the protocol
2535                                 PutWithNul(&data_out_p, len_out, "challenge ");
2536                                 *len_out = data_out_p - data_out;
2537                                 --*len_out; // remove NUL terminator
2538                                 return CRYPTO_REPLACE;
2539                         }
2540                 }
2541                 else if(!strcmp(cnt, "5"))
2542                 {
2543                         size_t fpbuflen;
2544                         unsigned char dhkey[DHKEY_SIZE];
2545                         int i;
2546
2547                         if(id >= 0)
2548                                 if(CDATA->cdata_id != id)
2549                                         return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2550                         if(CDATA->next_step != 5)
2551                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2552
2553                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2554
2555                         if(CDATA->s < 0) // only if server didn't auth
2556                         {
2557                                 if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2558                                         aes = atoi(s);
2559                                 else
2560                                         aes = false;
2561                                 if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2562                                 if(!aes && CDATA->wantserver_aes)
2563                                 {
2564                                         CLEAR_CDATA;
2565                                         return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2566                                 }
2567                                 if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2568                                 {
2569                                         CLEAR_CDATA;
2570                                         return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2571                                 }
2572                                 if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2573                                 {
2574                                         CLEAR_CDATA;
2575                                         return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2576                                 }
2577                                 crypto->use_aes = aes != 0;
2578                         }
2579
2580                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\6\\id\\%d", CDATA->cdata_id));
2581                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
2582                         {
2583                                 CLEAR_CDATA;
2584                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed");
2585                         }
2586                         fpbuflen = DHKEY_SIZE;
2587                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
2588                         {
2589                                 CLEAR_CDATA;
2590                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2591                         }
2592                         // XOR the two DH keys together to make one
2593                         for(i = 0; i < DHKEY_SIZE; ++i)
2594                                 crypto->dhkey[i] ^= dhkey[i];
2595                         // session key is FINISHED! By this, all keys are set up
2596                         crypto->authenticated = true;
2597                         CDATA->next_step = 0;
2598                         data_out_p += *len_out;
2599                         *len_out = data_out_p - data_out;
2600                         return CRYPTO_DISCARD;
2601                 }
2602                 return Crypto_SoftClientError(data_out, len_out, "Got unknown d0_blind_id message from server");
2603         }
2604
2605         return CRYPTO_NOMATCH;
2606 }
2607
2608 size_t Crypto_SignData(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2609 {
2610         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2611                 return 0;
2612         if(!pubkeys_havepriv[keyid])
2613                 return 0;
2614         if(qd0_blind_id_sign_with_private_id_sign(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2615                 return signed_size;
2616         return 0;
2617 }
2618
2619 size_t Crypto_SignDataDetached(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2620 {
2621         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2622                 return 0;
2623         if(!pubkeys_havepriv[keyid])
2624                 return 0;
2625         if(qd0_blind_id_sign_with_private_id_sign_detached(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2626                 return signed_size;
2627         return 0;
2628 }