crypto.c

   1 // TODO key loading, generating, saving
   2 #include "quakedef.h"
   3 #include "crypto.h"
   4 #include "common.h"
   5 #include "thread.h"
   6
   7 #include "hmac.h"
   8 #include "libcurl.h"
   9
  10 cvar_t crypto_developer = {CVAR_SAVE, "crypto_developer", "0", "print extra info about crypto handshake"};
  11 cvar_t crypto_servercpupercent = {CVAR_SAVE, "crypto_servercpupercent", "10", "allowed crypto CPU load in percent for server operation (0 = no limit, faster)"};
  12 cvar_t crypto_servercpumaxtime = {CVAR_SAVE, "crypto_servercpumaxtime", "0.01", "maximum allowed crypto CPU time per frame (0 = no limit)"};
  13 cvar_t crypto_servercpudebug = {CVAR_SAVE, "crypto_servercpudebug", "0", "print statistics about time usage by crypto"};
  14 static double crypto_servercpu_accumulator = 0;
  15 static double crypto_servercpu_lastrealtime = 0;
  16 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)"};
  17 int crypto_keyfp_recommended_length;
  18 static const char *crypto_idstring = NULL;
  19 static char crypto_idstring_buf[512];
  20
  21 #define PROTOCOL_D0_BLIND_ID FOURCC_D0PK
  22 #define PROTOCOL_VLEN (('v' << 0) | ('l' << 8) | ('e' << 16) | ('n' << 24))
  23
  24 // BEGIN stuff shared with crypto-keygen-standalone
  25 #define FOURCC_D0PK (('d' << 0) | ('0' << 8) | ('p' << 16) | ('k' << 24))
  26 #define FOURCC_D0SK (('d' << 0) | ('0' << 8) | ('s' << 16) | ('k' << 24))
  27 #define FOURCC_D0PI (('d' << 0) | ('0' << 8) | ('p' << 16) | ('i' << 24))
  28 #define FOURCC_D0SI (('d' << 0) | ('0' << 8) | ('s' << 16) | ('i' << 24))
  29 #define FOURCC_D0IQ (('d' << 0) | ('0' << 8) | ('i' << 16) | ('q' << 24))
  30 #define FOURCC_D0IR (('d' << 0) | ('0' << 8) | ('i' << 16) | ('r' << 24))
  31 #define FOURCC_D0ER (('d' << 0) | ('0' << 8) | ('e' << 16) | ('r' << 24))
  32 #define FOURCC_D0IC (('d' << 0) | ('0' << 8) | ('i' << 16) | ('c' << 24))
  33
  34 static unsigned long Crypto_LittleLong(const char *data)
  35 {
  36         return
  37                 ((unsigned char) data[0]) |
  38                 (((unsigned char) data[1]) << 8) |
  39                 (((unsigned char) data[2]) << 16) |
  40                 (((unsigned char) data[3]) << 24);
  41 }
  42
  43 static void Crypto_UnLittleLong(char *data, unsigned long l)
  44 {
  45         data[0] = l & 0xFF;
  46         data[1] = (l >> 8) & 0xFF;
  47         data[2] = (l >> 16) & 0xFF;
  48         data[3] = (l >> 24) & 0xFF;
  49 }
  50
  51 static size_t Crypto_ParsePack(const char *buf, size_t len, unsigned long header, const char **lumps, size_t *lumpsize, size_t nlumps)
  52 {
  53         size_t i;
  54         size_t pos;
  55         pos = 0;
  56         if(header)
  57         {
  58                 if(len < 4)
  59                         return 0;
  60                 if(Crypto_LittleLong(buf) != header)
  61                         return 0;
  62                 pos += 4;
  63         }
  64         for(i = 0; i < nlumps; ++i)
  65         {
  66                 if(pos + 4 > len)
  67                         return 0;
  68                 lumpsize[i] = Crypto_LittleLong(&buf[pos]);
  69                 pos += 4;
  70                 if(pos + lumpsize[i] > len)
  71                         return 0;
  72                 lumps[i] = &buf[pos];
  73                 pos += lumpsize[i];
  74         }
  75         return pos;
  76 }
  77
  78 static size_t Crypto_UnParsePack(char *buf, size_t len, unsigned long header, const char *const *lumps, const size_t *lumpsize, size_t nlumps)
  79 {
  80         size_t i;
  81         size_t pos;
  82         pos = 0;
  83         if(header)
  84         {
  85                 if(len < 4)
  86                         return 0;
  87                 Crypto_UnLittleLong(buf, header);
  88                 pos += 4;
  89         }
  90         for(i = 0; i < nlumps; ++i)
  91         {
  92                 if(pos + 4 + lumpsize[i] > len)
  93                         return 0;
  94                 Crypto_UnLittleLong(&buf[pos], lumpsize[i]);
  95                 pos += 4;
  96                 memcpy(&buf[pos], lumps[i], lumpsize[i]);
  97                 pos += lumpsize[i];
  98         }
  99         return pos;
 100 }
 101 // END stuff shared with xonotic-keygen
 102
 103 #define USE_AES
 104
 105 #ifdef CRYPTO_STATIC
 106
 107 #include <d0_blind_id/d0_blind_id.h>
 108
 109 #define d0_blind_id_dll 1
 110 #define Crypto_OpenLibrary() true
 111 #define Crypto_CloseLibrary()
 112
 113 #define qd0_blind_id_new d0_blind_id_new
 114 #define qd0_blind_id_free d0_blind_id_free
 115 //#define qd0_blind_id_clear d0_blind_id_clear
 116 #define qd0_blind_id_copy d0_blind_id_copy
 117 //#define qd0_blind_id_generate_private_key d0_blind_id_generate_private_key
 118 //#define qd0_blind_id_generate_private_key_fastreject d0_blind_id_generate_private_key_fastreject
 119 //#define qd0_blind_id_read_private_key d0_blind_id_read_private_key
 120 #define qd0_blind_id_read_public_key d0_blind_id_read_public_key
 121 //#define qd0_blind_id_write_private_key d0_blind_id_write_private_key
 122 //#define qd0_blind_id_write_public_key d0_blind_id_write_public_key
 123 #define qd0_blind_id_fingerprint64_public_key d0_blind_id_fingerprint64_public_key
 124 //#define qd0_blind_id_generate_private_id_modulus d0_blind_id_generate_private_id_modulus
 125 #define qd0_blind_id_read_private_id_modulus d0_blind_id_read_private_id_modulus
 126 //#define qd0_blind_id_write_private_id_modulus d0_blind_id_write_private_id_modulus
 127 #define qd0_blind_id_generate_private_id_start d0_blind_id_generate_private_id_start
 128 #define qd0_blind_id_generate_private_id_request d0_blind_id_generate_private_id_request
 129 //#define qd0_blind_id_answer_private_id_request d0_blind_id_answer_private_id_request
 130 #define qd0_blind_id_finish_private_id_request d0_blind_id_finish_private_id_request
 131 //#define qd0_blind_id_read_private_id_request_camouflage d0_blind_id_read_private_id_request_camouflage
 132 //#define qd0_blind_id_write_private_id_request_camouflage d0_blind_id_write_private_id_request_camouflage
 133 #define qd0_blind_id_read_private_id d0_blind_id_read_private_id
 134 //#define qd0_blind_id_read_public_id d0_blind_id_read_public_id
 135 #define qd0_blind_id_write_private_id d0_blind_id_write_private_id
 136 //#define qd0_blind_id_write_public_id d0_blind_id_write_public_id
 137 #define qd0_blind_id_authenticate_with_private_id_start d0_blind_id_authenticate_with_private_id_start
 138 #define qd0_blind_id_authenticate_with_private_id_challenge d0_blind_id_authenticate_with_private_id_challenge
 139 #define qd0_blind_id_authenticate_with_private_id_response d0_blind_id_authenticate_with_private_id_response
 140 #define qd0_blind_id_authenticate_with_private_id_verify d0_blind_id_authenticate_with_private_id_verify
 141 #define qd0_blind_id_fingerprint64_public_id d0_blind_id_fingerprint64_public_id
 142 #define qd0_blind_id_sessionkey_public_id d0_blind_id_sessionkey_public_id
 143 #define qd0_blind_id_INITIALIZE d0_blind_id_INITIALIZE
 144 #define qd0_blind_id_SHUTDOWN d0_blind_id_SHUTDOWN
 145 #define qd0_blind_id_util_sha256 d0_blind_id_util_sha256
 146 #define qd0_blind_id_sign_with_private_id_sign d0_blind_id_sign_with_private_id_sign
 147 #define qd0_blind_id_sign_with_private_id_sign_detached d0_blind_id_sign_with_private_id_sign_detached
 148 #define qd0_blind_id_setmallocfuncs d0_blind_id_setmallocfuncs
 149 #define qd0_blind_id_setmutexfuncs d0_blind_id_setmutexfuncs
 150 #define qd0_blind_id_verify_public_id d0_bind_id_verify_public_id
 151 #define qd0_blind_id_verify_private_id d0_bind_id_verify_private_id
 152
 153 #else
 154
 155 // d0_blind_id interface
 156 #define D0_EXPORT
 157 #ifdef __GNUC__
 158 #define D0_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 159 #else
 160 #define D0_WARN_UNUSED_RESULT
 161 #endif
 162 #define D0_BOOL int
 163
 164 typedef void *(d0_malloc_t)(size_t len);
 165 typedef void (d0_free_t)(void *p);
 166 typedef void *(d0_createmutex_t)(void);
 167 typedef void (d0_destroymutex_t)(void *);
 168 typedef int (d0_lockmutex_t)(void *); // zero on success
 169 typedef int (d0_unlockmutex_t)(void *); // zero on success
 170
 171 typedef struct d0_blind_id_s d0_blind_id_t;
 172 typedef D0_BOOL (*d0_fastreject_function) (const d0_blind_id_t *ctx, void *pass);
 173 static D0_EXPORT D0_WARN_UNUSED_RESULT d0_blind_id_t *(*qd0_blind_id_new) (void);
 174 static D0_EXPORT void (*qd0_blind_id_free) (d0_blind_id_t *a);
 175 //static D0_EXPORT void (*qd0_blind_id_clear) (d0_blind_id_t *ctx);
 176 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_copy) (d0_blind_id_t *ctx, const d0_blind_id_t *src);
 177 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key) (d0_blind_id_t *ctx, int k);
 178 //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);
 179 //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);
 180 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);
 181 //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);
 182 //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);
 183 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);
 184 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_modulus) (d0_blind_id_t *ctx);
 185 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);
 186 //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);
 187 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_start) (d0_blind_id_t *ctx);
 188 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);
 189 //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);
 190 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);
 191 //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);
 192 //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);
 193 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);
 194 //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);
 195 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);
 196 //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);
 197 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);
 198 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);
 199 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);
 200 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);
 201 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);
 202 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
 203 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_INITIALIZE) (void);
 204 static D0_EXPORT void (*qd0_blind_id_SHUTDOWN) (void);
 205 static D0_EXPORT void (*qd0_blind_id_util_sha256) (char *out, const char *in, size_t n);
 206 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);
 207 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);
 208 static D0_EXPORT void (*qd0_blind_id_setmallocfuncs)(d0_malloc_t *m, d0_free_t *f);
 209 static D0_EXPORT void (*qd0_blind_id_setmutexfuncs)(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u);
 210 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_public_id)(const d0_blind_id_t *ctx, D0_BOOL *status);
 211 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_private_id)(const d0_blind_id_t *ctx);
 212 static dllfunction_t d0_blind_id_funcs[] =
 213 {
 214         {"d0_blind_id_new", (void **) &qd0_blind_id_new},
 215         {"d0_blind_id_free", (void **) &qd0_blind_id_free},
 216         //{"d0_blind_id_clear", (void **) &qd0_blind_id_clear},
 217         {"d0_blind_id_copy", (void **) &qd0_blind_id_copy},
 218         //{"d0_blind_id_generate_private_key", (void **) &qd0_blind_id_generate_private_key},
 219         //{"d0_blind_id_generate_private_key_fastreject", (void **) &qd0_blind_id_generate_private_key_fastreject},
 220         //{"d0_blind_id_read_private_key", (void **) &qd0_blind_id_read_private_key},
 221         {"d0_blind_id_read_public_key", (void **) &qd0_blind_id_read_public_key},
 222         //{"d0_blind_id_write_private_key", (void **) &qd0_blind_id_write_private_key},
 223         //{"d0_blind_id_write_public_key", (void **) &qd0_blind_id_write_public_key},
 224         {"d0_blind_id_fingerprint64_public_key", (void **) &qd0_blind_id_fingerprint64_public_key},
 225         //{"d0_blind_id_generate_private_id_modulus", (void **) &qd0_blind_id_generate_private_id_modulus},
 226         {"d0_blind_id_read_private_id_modulus", (void **) &qd0_blind_id_read_private_id_modulus},
 227         //{"d0_blind_id_write_private_id_modulus", (void **) &qd0_blind_id_write_private_id_modulus},
 228         {"d0_blind_id_generate_private_id_start", (void **) &qd0_blind_id_generate_private_id_start},
 229         {"d0_blind_id_generate_private_id_request", (void **) &qd0_blind_id_generate_private_id_request},
 230         //{"d0_blind_id_answer_private_id_request", (void **) &qd0_blind_id_answer_private_id_request},
 231         {"d0_blind_id_finish_private_id_request", (void **) &qd0_blind_id_finish_private_id_request},
 232         //{"d0_blind_id_read_private_id_request_camouflage", (void **) &qd0_blind_id_read_private_id_request_camouflage},
 233         //{"d0_blind_id_write_private_id_request_camouflage", (void **) &qd0_blind_id_write_private_id_request_camouflage},
 234         {"d0_blind_id_read_private_id", (void **) &qd0_blind_id_read_private_id},
 235         //{"d0_blind_id_read_public_id", (void **) &qd0_blind_id_read_public_id},
 236         {"d0_blind_id_write_private_id", (void **) &qd0_blind_id_write_private_id},
 237         //{"d0_blind_id_write_public_id", (void **) &qd0_blind_id_write_public_id},
 238         {"d0_blind_id_authenticate_with_private_id_start", (void **) &qd0_blind_id_authenticate_with_private_id_start},
 239         {"d0_blind_id_authenticate_with_private_id_challenge", (void **) &qd0_blind_id_authenticate_with_private_id_challenge},
 240         {"d0_blind_id_authenticate_with_private_id_response", (void **) &qd0_blind_id_authenticate_with_private_id_response},
 241         {"d0_blind_id_authenticate_with_private_id_verify", (void **) &qd0_blind_id_authenticate_with_private_id_verify},
 242         {"d0_blind_id_fingerprint64_public_id", (void **) &qd0_blind_id_fingerprint64_public_id},
 243         {"d0_blind_id_sessionkey_public_id", (void **) &qd0_blind_id_sessionkey_public_id},
 244         {"d0_blind_id_INITIALIZE", (void **) &qd0_blind_id_INITIALIZE},
 245         {"d0_blind_id_SHUTDOWN", (void **) &qd0_blind_id_SHUTDOWN},
 246         {"d0_blind_id_util_sha256", (void **) &qd0_blind_id_util_sha256},
 247         {"d0_blind_id_sign_with_private_id_sign", (void **) &qd0_blind_id_sign_with_private_id_sign},
 248         {"d0_blind_id_sign_with_private_id_sign_detached", (void **) &qd0_blind_id_sign_with_private_id_sign_detached},
 249         {"d0_blind_id_setmallocfuncs", (void **) &qd0_blind_id_setmallocfuncs},
 250         {"d0_blind_id_setmutexfuncs", (void **) &qd0_blind_id_setmutexfuncs},
 251         {"d0_blind_id_verify_public_id", (void **) &qd0_blind_id_verify_public_id},
 252         {"d0_blind_id_verify_private_id", (void **) &qd0_blind_id_verify_private_id},
 253         {NULL, NULL}
 254 };
 255 // end of d0_blind_id interface
 256
 257 static dllhandle_t d0_blind_id_dll = NULL;
 258 static qboolean Crypto_OpenLibrary (void)
 259 {
 260         const char* dllnames [] =
 261         {
 262 #if defined(WIN32)
 263                 "libd0_blind_id-0.dll",
 264 #elif defined(MACOSX)
 265                 "libd0_blind_id.0.dylib",
 266 #else
 267                 "libd0_blind_id.so.0",
 268                 "libd0_blind_id.so", // FreeBSD
 269 #endif
 270                 NULL
 271         };
 272
 273         // Already loaded?
 274         if (d0_blind_id_dll)
 275                 return true;
 276
 277         // Load the DLL
 278         return Sys_LoadLibrary (dllnames, &d0_blind_id_dll, d0_blind_id_funcs);
 279 }
 280
 281 static void Crypto_CloseLibrary (void)
 282 {
 283         Sys_UnloadLibrary (&d0_blind_id_dll);
 284 }
 285
 286 #endif
 287
 288 #ifdef CRYPTO_RIJNDAEL_STATIC
 289
 290 #include <d0_blind_id/d0_rijndael.h>
 291
 292 #define d0_rijndael_dll 1
 293 #define Crypto_Rijndael_OpenLibrary() true
 294 #define Crypto_Rijndael_CloseLibrary()
 295
 296 #define qd0_rijndael_setup_encrypt d0_rijndael_setup_encrypt
 297 #define qd0_rijndael_setup_decrypt d0_rijndael_setup_decrypt
 298 #define qd0_rijndael_encrypt d0_rijndael_encrypt
 299 #define qd0_rijndael_decrypt d0_rijndael_decrypt
 300
 301 #else
 302
 303 // no need to do the #define dance here, as the upper part declares out macros either way
 304
 305 D0_EXPORT int (*qd0_rijndael_setup_encrypt) (unsigned long *rk, const unsigned char *key,
 306   int keybits);
 307 D0_EXPORT int (*qd0_rijndael_setup_decrypt) (unsigned long *rk, const unsigned char *key,
 308   int keybits);
 309 D0_EXPORT void (*qd0_rijndael_encrypt) (const unsigned long *rk, int nrounds,
 310   const unsigned char plaintext[16], unsigned char ciphertext[16]);
 311 D0_EXPORT void (*qd0_rijndael_decrypt) (const unsigned long *rk, int nrounds,
 312   const unsigned char ciphertext[16], unsigned char plaintext[16]);
 313 #define D0_RIJNDAEL_KEYLENGTH(keybits) ((keybits)/8)
 314 #define D0_RIJNDAEL_RKLENGTH(keybits)  ((keybits)/8+28)
 315 #define D0_RIJNDAEL_NROUNDS(keybits)   ((keybits)/32+6)
 316 static dllfunction_t d0_rijndael_funcs[] =
 317 {
 318         {"d0_rijndael_setup_decrypt", (void **) &qd0_rijndael_setup_decrypt},
 319         {"d0_rijndael_setup_encrypt", (void **) &qd0_rijndael_setup_encrypt},
 320         {"d0_rijndael_decrypt", (void **) &qd0_rijndael_decrypt},
 321         {"d0_rijndael_encrypt", (void **) &qd0_rijndael_encrypt},
 322         {NULL, NULL}
 323 };
 324 // end of d0_blind_id interface
 325
 326 static dllhandle_t d0_rijndael_dll = NULL;
 327 static qboolean Crypto_Rijndael_OpenLibrary (void)
 328 {
 329         const char* dllnames [] =
 330         {
 331 #if defined(WIN32)
 332                 "libd0_rijndael-0.dll",
 333 #elif defined(MACOSX)
 334                 "libd0_rijndael.0.dylib",
 335 #else
 336                 "libd0_rijndael.so.0",
 337                 "libd0_rijndael.so", // FreeBSD
 338 #endif
 339                 NULL
 340         };
 341
 342         // Already loaded?
 343         if (d0_rijndael_dll)
 344                 return true;
 345
 346         // Load the DLL
 347         return Sys_LoadLibrary (dllnames, &d0_rijndael_dll, d0_rijndael_funcs);
 348 }
 349
 350 static void Crypto_Rijndael_CloseLibrary (void)
 351 {
 352         Sys_UnloadLibrary (&d0_rijndael_dll);
 353 }
 354
 355 #endif
 356
 357 // various helpers
 358 void sha256(unsigned char *out, const unsigned char *in, int n)
 359 {
 360         qd0_blind_id_util_sha256((char *) out, (const char *) in, n);
 361 }
 362
 363 static size_t Crypto_LoadFile(const char *path, char *buf, size_t nmax, qboolean inuserdir)
 364 {
 365         char vabuf[1024];
 366         qfile_t *f = NULL;
 367         fs_offset_t n;
 368         if(inuserdir)
 369                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", *fs_userdir ? fs_userdir : fs_basedir, path), "rb", false);
 370         else
 371                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", fs_basedir, path), "rb", false);
 372         if(!f)
 373                 return 0;
 374         n = FS_Read(f, buf, nmax);
 375         if(n < 0)
 376                 n = 0;
 377         FS_Close(f);
 378         return (size_t) n;
 379 }
 380
 381 static qboolean PutWithNul(char **data, size_t *len, const char *str)
 382 {
 383         // invariant: data points to insertion point
 384         size_t l = strlen(str);
 385         if(l >= *len)
 386                 return false;
 387         memcpy(*data, str, l+1);
 388         *data += l+1;
 389         *len -= l+1;
 390         return true;
 391 }
 392
 393 static const char *GetUntilNul(const char **data, size_t *len)
 394 {
 395         // invariant: data points to next character to take
 396         const char *data_save = *data;
 397         size_t n;
 398         const char *p;
 399
 400         if(!*data)
 401                 return NULL;
 402
 403         if(!*len)
 404         {
 405                 *data = NULL;
 406                 return NULL;
 407         }
 408
 409         p = (const char *) memchr(*data, 0, *len);
 410         if(!p) // no terminating NUL
 411         {
 412                 *data = NULL;
 413                 *len = 0;
 414                 return NULL;
 415         }
 416         else
 417         {
 418                 n = (p - *data) + 1;
 419                 *len -= n;
 420                 *data += n;
 421                 if(*len == 0)
 422                         *data = NULL;
 423                 return (const char *) data_save;
 424         }
 425         *data = NULL;
 426         return NULL;
 427 }
 428
 429 // d0pk reading
 430 static d0_blind_id_t *Crypto_ReadPublicKey(char *buf, size_t len)
 431 {
 432         d0_blind_id_t *pk = NULL;
 433         const char *p[2];
 434         size_t l[2];
 435         if(Crypto_ParsePack(buf, len, FOURCC_D0PK, p, l, 2))
 436         {
 437                 pk = qd0_blind_id_new();
 438                 if(pk)
 439                         if(qd0_blind_id_read_public_key(pk, p[0], l[0]))
 440                                 if(qd0_blind_id_read_private_id_modulus(pk, p[1], l[1]))
 441                                         return pk;
 442         }
 443         if(pk)
 444                 qd0_blind_id_free(pk);
 445         return NULL;
 446 }
 447
 448 // d0si reading
 449 static qboolean Crypto_AddPrivateKey(d0_blind_id_t *pk, char *buf, size_t len)
 450 {
 451         const char *p[1];
 452         size_t l[1];
 453         if(Crypto_ParsePack(buf, len, FOURCC_D0SI, p, l, 1))
 454         {
 455                 if(qd0_blind_id_read_private_id(pk, p[0], l[0]))
 456                         return true;
 457         }
 458         return false;
 459 }
 460
 461 #define MAX_PUBKEYS 16
 462 static d0_blind_id_t *pubkeys[MAX_PUBKEYS];
 463 static char pubkeys_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 464 static qboolean pubkeys_havepriv[MAX_PUBKEYS];
 465 static qboolean pubkeys_havesig[MAX_PUBKEYS];
 466 static char pubkeys_priv_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 467 static char challenge_append[1400];
 468 static size_t challenge_append_length;
 469
 470 static int keygen_i = -1;
 471 static char keygen_buf[8192];
 472
 473 #define MAX_CRYPTOCONNECTS 16
 474 #define CRYPTOCONNECT_NONE 0
 475 #define CRYPTOCONNECT_PRECONNECT 1
 476 #define CRYPTOCONNECT_CONNECT 2
 477 #define CRYPTOCONNECT_RECONNECT 3
 478 #define CRYPTOCONNECT_DUPLICATE 4
 479 typedef struct server_cryptoconnect_s
 480 {
 481         double lasttime;
 482         lhnetaddress_t address;
 483         crypto_t crypto;
 484         int next_step;
 485 }
 486 server_cryptoconnect_t;
 487 static server_cryptoconnect_t cryptoconnects[MAX_CRYPTOCONNECTS];
 488
 489 static int cdata_id = 0;
 490 typedef struct
 491 {
 492         d0_blind_id_t *id;
 493         int s, c;
 494         int next_step;
 495         char challenge[2048];
 496         char wantserver_idfp[FP64_SIZE+1];
 497         qboolean wantserver_aes;
 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_ServerFinishInstance(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 }
 566 crypto_storedhostkey_t;
 567 static crypto_storedhostkey_t *crypto_storedhostkey_hashtable[CRYPTO_HOSTKEY_HASHSIZE];
 568
 569 static void Crypto_InitHostKeys(void)
 570 {
 571         int i;
 572         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 573                 crypto_storedhostkey_hashtable[i] = NULL;
 574 }
 575
 576 static void Crypto_ClearHostKeys(void)
 577 {
 578         int i;
 579         crypto_storedhostkey_t *hk, *hkn;
 580         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 581         {
 582                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hkn)
 583                 {
 584                         hkn = hk->next;
 585                         Z_Free(hk);
 586                 }
 587                 crypto_storedhostkey_hashtable[i] = NULL;
 588         }
 589 }
 590
 591 static qboolean Crypto_ClearHostKey(lhnetaddress_t *peeraddress)
 592 {
 593         char buf[128];
 594         int hashindex;
 595         crypto_storedhostkey_t **hkp;
 596         qboolean found = false;
 597
 598         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 599         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 600         for(hkp = &crypto_storedhostkey_hashtable[hashindex]; *hkp && LHNETADDRESS_Compare(&((*hkp)->addr), peeraddress); hkp = &((*hkp)->next));
 601
 602         if(*hkp)
 603         {
 604                 crypto_storedhostkey_t *hk = *hkp;
 605                 *hkp = hk->next;
 606                 Z_Free(hk);
 607                 found = true;
 608         }
 609
 610         return found;
 611 }
 612
 613 static void Crypto_StoreHostKey(lhnetaddress_t *peeraddress, const char *keystring, qboolean complain)
 614 {
 615         char buf[128];
 616         int hashindex;
 617         crypto_storedhostkey_t *hk;
 618         int keyid;
 619         char idfp[FP64_SIZE+1];
 620         int aeslevel;
 621
 622         if(!d0_blind_id_dll)
 623                 return;
 624
 625         // syntax of keystring:
 626         // aeslevel id@key id@key ...
 627
 628         if(!*keystring)
 629                 return;
 630         aeslevel = bound(0, *keystring - '0', 3);
 631         while(*keystring && *keystring != ' ')
 632                 ++keystring;
 633
 634         keyid = -1;
 635         while(*keystring && keyid < 0)
 636         {
 637                 // id@key
 638                 const char *idstart, *idend, *keystart, *keyend;
 639                 ++keystring; // skip the space
 640                 idstart = keystring;
 641                 while(*keystring && *keystring != ' ' && *keystring != '@')
 642                         ++keystring;
 643                 idend = keystring;
 644                 if(!*keystring)
 645                         break;
 646                 ++keystring;
 647                 keystart = keystring;
 648                 while(*keystring && *keystring != ' ')
 649                         ++keystring;
 650                 keyend = keystring;
 651
 652                 if(idend - idstart == FP64_SIZE && keyend - keystart == FP64_SIZE)
 653                 {
 654                         for(keyid = 0; keyid < MAX_PUBKEYS; ++keyid)
 655                                 if(pubkeys[keyid])
 656                                         if(!memcmp(pubkeys_fp64[keyid], keystart, FP64_SIZE))
 657                                         {
 658                                                 memcpy(idfp, idstart, FP64_SIZE);
 659                                                 idfp[FP64_SIZE] = 0;
 660                                                 break;
 661                                         }
 662                         if(keyid >= MAX_PUBKEYS)
 663                                 keyid = -1;
 664                 }
 665         }
 666
 667         if(keyid < 0)
 668                 return;
 669
 670         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 671         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 672         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 673
 674         if(hk)
 675         {
 676                 if(complain)
 677                 {
 678                         if(hk->keyid != keyid || memcmp(hk->idfp, idfp, FP64_SIZE+1))
 679                                 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);
 680                         if(hk->aeslevel > aeslevel)
 681                                 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);
 682                 }
 683                 hk->aeslevel = max(aeslevel, hk->aeslevel);
 684                 return;
 685         }
 686
 687         // great, we did NOT have it yet
 688         hk = (crypto_storedhostkey_t *) Z_Malloc(sizeof(*hk));
 689         memcpy(&hk->addr, peeraddress, sizeof(hk->addr));
 690         hk->keyid = keyid;
 691         memcpy(hk->idfp, idfp, FP64_SIZE+1);
 692         hk->next = crypto_storedhostkey_hashtable[hashindex];
 693         hk->aeslevel = aeslevel;
 694         crypto_storedhostkey_hashtable[hashindex] = hk;
 695 }
 696
 697 qboolean Crypto_RetrieveHostKey(lhnetaddress_t *peeraddress, int *keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, int *aeslevel)
 698 {
 699         char buf[128];
 700         int hashindex;
 701         crypto_storedhostkey_t *hk;
 702
 703         if(!d0_blind_id_dll)
 704                 return false;
 705
 706         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 707         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 708         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 709
 710         if(!hk)
 711                 return false;
 712
 713         if(keyid)
 714                 *keyid = hk->keyid;
 715         if(keyfp)
 716                 strlcpy(keyfp, pubkeys_fp64[hk->keyid], keyfplen);
 717         if(idfp)
 718                 strlcpy(idfp, hk->idfp, idfplen);
 719         if(aeslevel)
 720                 *aeslevel = hk->aeslevel;
 721
 722         return true;
 723 }
 724 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
 725 {
 726         if(keyid < 0 || keyid >= MAX_PUBKEYS)
 727                 return 0;
 728         if(keyfp)
 729                 *keyfp = 0;
 730         if(idfp)
 731                 *idfp = 0;
 732         if(!pubkeys[keyid])
 733                 return -1;
 734         if(keyfp)
 735                 strlcpy(keyfp, pubkeys_fp64[keyid], keyfplen);
 736         if(idfp)
 737                 if(pubkeys_havepriv[keyid])
 738                         strlcpy(idfp, pubkeys_priv_fp64[keyid], keyfplen);
 739         if(issigned)
 740                 *issigned = pubkeys_havesig[keyid];
 741         return 1;
 742 }
 743 // end
 744
 745 // init/shutdown code
 746 static void Crypto_BuildChallengeAppend(void)
 747 {
 748         char *p, *lengthptr, *startptr;
 749         size_t n;
 750         int i;
 751         p = challenge_append;
 752         n = sizeof(challenge_append);
 753         Crypto_UnLittleLong(p, PROTOCOL_VLEN);
 754         p += 4;
 755         n -= 4;
 756         lengthptr = p;
 757         Crypto_UnLittleLong(p, 0);
 758         p += 4;
 759         n -= 4;
 760         Crypto_UnLittleLong(p, PROTOCOL_D0_BLIND_ID);
 761         p += 4;
 762         n -= 4;
 763         startptr = p;
 764         for(i = 0; i < MAX_PUBKEYS; ++i)
 765                 if(pubkeys_havepriv[i])
 766                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 767         PutWithNul(&p, &n, "");
 768         for(i = 0; i < MAX_PUBKEYS; ++i)
 769                 if(!pubkeys_havepriv[i] && pubkeys[i])
 770                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 771         Crypto_UnLittleLong(lengthptr, p - startptr);
 772         challenge_append_length = p - challenge_append;
 773 }
 774
 775 void Crypto_LoadKeys(void)
 776 {
 777         char buf[8192];
 778         size_t len, len2;
 779         int i;
 780         char vabuf[1024];
 781
 782         if(!d0_blind_id_dll) // don't if we can't
 783                 return;
 784
 785         if(crypto_idstring) // already loaded? then not
 786                 return;
 787
 788         Host_LockSession(); // we use the session ID here
 789
 790         // load keys
 791         // note: we are just a CLIENT
 792         // so we load:
 793         //   PUBLIC KEYS to accept (including modulus)
 794         //   PRIVATE KEY of user
 795
 796         crypto_idstring = NULL;
 797         dpsnprintf(crypto_idstring_buf, sizeof(crypto_idstring_buf), "%d", d0_rijndael_dll ? crypto_aeslevel.integer : 0);
 798         for(i = 0; i < MAX_PUBKEYS; ++i)
 799         {
 800                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 801                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 802                 pubkeys_havepriv[i] = false;
 803                 pubkeys_havesig[i] = false;
 804                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0pk", i), buf, sizeof(buf), false);
 805                 if((pubkeys[i] = Crypto_ReadPublicKey(buf, len)))
 806                 {
 807                         len2 = FP64_SIZE;
 808                         if(qd0_blind_id_fingerprint64_public_key(pubkeys[i], pubkeys_fp64[i], &len2)) // keeps final NUL
 809                         {
 810                                 Con_Printf("Loaded public key key_%d.d0pk (fingerprint: %s)\n", i, pubkeys_fp64[i]);
 811                                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0si%s", i, sessionid.string), buf, sizeof(buf), true);
 812                                 if(len)
 813                                 {
 814                                         if(Crypto_AddPrivateKey(pubkeys[i], buf, len))
 815                                         {
 816                                                 len2 = FP64_SIZE;
 817                                                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[i], pubkeys_priv_fp64[i], &len2)) // keeps final NUL
 818                                                 {
 819                                                         D0_BOOL status = 0;
 820
 821                                                         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]);
 822
 823                                                         // verify the key we just loaded (just in case)
 824                                                         if(qd0_blind_id_verify_private_id(pubkeys[i]) && qd0_blind_id_verify_public_id(pubkeys[i], &status))
 825                                                         {
 826                                                                 pubkeys_havepriv[i] = true;
 827                                                                 strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[i], pubkeys_fp64[i]), sizeof(crypto_idstring_buf));
 828
 829                                                                 // verify the key we just got (just in case)
 830                                                                 if(status)
 831                                                                         pubkeys_havesig[i] = true;
 832                                                                 else
 833                                                                         Con_Printf("NOTE: this ID has not yet been signed!\n");
 834                                                         }
 835                                                         else
 836                                                         {
 837                                                                 Con_Printf("d0_blind_id_verify_private_id failed, this is not a valid key!\n");
 838                                                                 qd0_blind_id_free(pubkeys[i]);
 839                                                                 pubkeys[i] = NULL;
 840                                                         }
 841                                                 }
 842                                                 else
 843                                                 {
 844                                                         Con_Printf("d0_blind_id_fingerprint64_public_id failed\n");
 845                                                         qd0_blind_id_free(pubkeys[i]);
 846                                                         pubkeys[i] = NULL;
 847                                                 }
 848                                         }
 849                                 }
 850                         }
 851                         else
 852                         {
 853                                 // can't really happen
 854                                 qd0_blind_id_free(pubkeys[i]);
 855                                 pubkeys[i] = NULL;
 856                         }
 857                 }
 858         }
 859         crypto_idstring = crypto_idstring_buf;
 860
 861         keygen_i = -1;
 862         Crypto_BuildChallengeAppend();
 863
 864         // find a good prefix length for all the keys we know (yes, algorithm is not perfect yet, may yield too long prefix length)
 865         crypto_keyfp_recommended_length = 0;
 866         memset(buf+256, 0, MAX_PUBKEYS + MAX_PUBKEYS);
 867         while(crypto_keyfp_recommended_length < FP64_SIZE)
 868         {
 869                 memset(buf, 0, 256);
 870                 for(i = 0; i < MAX_PUBKEYS; ++i)
 871                         if(pubkeys[i])
 872                         {
 873                                 if(!buf[256 + i])
 874                                         ++buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]];
 875                                 if(pubkeys_havepriv[i])
 876                                         if(!buf[256 + MAX_PUBKEYS + i])
 877                                                 ++buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]];
 878                         }
 879                 for(i = 0; i < MAX_PUBKEYS; ++i)
 880                         if(pubkeys[i])
 881                         {
 882                                 if(!buf[256 + i])
 883                                         if(buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]] < 2)
 884                                                 buf[256 + i] = 1;
 885                                 if(pubkeys_havepriv[i])
 886                                         if(!buf[256 + MAX_PUBKEYS + i])
 887                                                 if(buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]] < 2)
 888                                                         buf[256 + MAX_PUBKEYS + i] = 1;
 889                         }
 890                 ++crypto_keyfp_recommended_length;
 891                 for(i = 0; i < MAX_PUBKEYS; ++i)
 892                         if(pubkeys[i])
 893                         {
 894                                 if(!buf[256 + i])
 895                                         break;
 896                                 if(pubkeys_havepriv[i])
 897                                         if(!buf[256 + MAX_PUBKEYS + i])
 898                                                 break;
 899                         }
 900                 if(i >= MAX_PUBKEYS)
 901                         break;
 902         }
 903         if(crypto_keyfp_recommended_length < 7)
 904                 crypto_keyfp_recommended_length = 7;
 905 }
 906
 907 static void Crypto_UnloadKeys(void)
 908 {
 909         int i;
 910
 911         keygen_i = -1;
 912         for(i = 0; i < MAX_PUBKEYS; ++i)
 913         {
 914                 if(pubkeys[i])
 915                         qd0_blind_id_free(pubkeys[i]);
 916                 pubkeys[i] = NULL;
 917                 pubkeys_havepriv[i] = false;
 918                 pubkeys_havesig[i] = false;
 919                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 920                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 921                 challenge_append_length = 0;
 922         }
 923         crypto_idstring = NULL;
 924 }
 925
 926 static mempool_t *cryptomempool;
 927
 928 #ifdef __cplusplus
 929 extern "C"
 930 {
 931 #endif
 932 static void *Crypto_d0_malloc(size_t len)
 933 {
 934         return Mem_Alloc(cryptomempool, len);
 935 }
 936
 937 static void Crypto_d0_free(void *p)
 938 {
 939         Mem_Free(p);
 940 }
 941
 942 static void *Crypto_d0_createmutex(void)
 943 {
 944         return Thread_CreateMutex();
 945 }
 946
 947 static void Crypto_d0_destroymutex(void *m)
 948 {
 949         Thread_DestroyMutex(m);
 950 }
 951
 952 static int Crypto_d0_lockmutex(void *m)
 953 {
 954         return Thread_LockMutex(m);
 955 }
 956
 957 static int Crypto_d0_unlockmutex(void *m)
 958 {
 959         return Thread_UnlockMutex(m);
 960 }
 961 #ifdef __cplusplus
 962 }
 963 #endif
 964
 965 void Crypto_Shutdown(void)
 966 {
 967         crypto_t *crypto;
 968         int i;
 969
 970         Crypto_Rijndael_CloseLibrary();
 971
 972         if(d0_blind_id_dll)
 973         {
 974                 // free memory
 975                 for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 976                 {
 977                         crypto = &cryptoconnects[i].crypto;
 978                         CLEAR_CDATA;
 979                 }
 980                 memset(cryptoconnects, 0, sizeof(cryptoconnects));
 981                 crypto = &cls.crypto;
 982                 CLEAR_CDATA;
 983
 984                 Crypto_UnloadKeys();
 985
 986                 qd0_blind_id_SHUTDOWN();
 987
 988                 Crypto_CloseLibrary();
 989         }
 990
 991         Mem_FreePool(&cryptomempool);
 992 }
 993
 994 void Crypto_Init(void)
 995 {
 996         cryptomempool = Mem_AllocPool("crypto", 0, NULL);
 997
 998         if(!Crypto_OpenLibrary())
 999                 return;
1000
1001         qd0_blind_id_setmallocfuncs(Crypto_d0_malloc, Crypto_d0_free);
1002         if (Thread_HasThreads())
1003                 qd0_blind_id_setmutexfuncs(Crypto_d0_createmutex, Crypto_d0_destroymutex, Crypto_d0_lockmutex, Crypto_d0_unlockmutex);
1004
1005         if(!qd0_blind_id_INITIALIZE())
1006         {
1007                 Crypto_Rijndael_CloseLibrary();
1008                 Crypto_CloseLibrary();
1009                 Con_Printf("libd0_blind_id initialization FAILED, cryptography support has been disabled\n");
1010                 return;
1011         }
1012
1013         Crypto_Rijndael_OpenLibrary(); // if this fails, it's uncritical
1014
1015         Crypto_InitHostKeys();
1016 }
1017 // end
1018
1019 qboolean Crypto_Available(void)
1020 {
1021         if(!d0_blind_id_dll)
1022                 return false;
1023         return true;
1024 }
1025
1026 // keygen code
1027 static void Crypto_KeyGen_Finished(int code, size_t length_received, unsigned char *buffer, void *cbdata)
1028 {
1029         const char *p[1];
1030         size_t l[1];
1031         static char buf[8192];
1032         static char buf2[8192];
1033         size_t buf2size;
1034         qfile_t *f = NULL;
1035         D0_BOOL status;
1036         char vabuf[1024];
1037
1038         SV_LockThreadMutex();
1039
1040         if(!d0_blind_id_dll)
1041         {
1042                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1043                 keygen_i = -1;
1044                 SV_UnlockThreadMutex();
1045                 return;
1046         }
1047
1048         if(keygen_i >= MAX_PUBKEYS || !pubkeys[keygen_i])
1049         {
1050                 Con_Printf("overflow of keygen_i\n");
1051                 keygen_i = -1;
1052                 SV_UnlockThreadMutex();
1053                 return;
1054         }
1055         if(keygen_i < 0)
1056         {
1057                 Con_Printf("Unexpected response from keygen server:\n");
1058                 Com_HexDumpToConsole(buffer, length_received);
1059                 SV_UnlockThreadMutex();
1060                 return;
1061         }
1062         if(!Crypto_ParsePack((const char *) buffer, length_received, FOURCC_D0IR, p, l, 1))
1063         {
1064                 if(length_received >= 5 && Crypto_LittleLong((const char *) buffer) == FOURCC_D0ER)
1065                 {
1066                         Con_Printf("Error response from keygen server: %.*s\n", (int)(length_received - 5), buffer + 5);
1067                 }
1068                 else
1069                 {
1070                         Con_Printf("Invalid response from keygen server:\n");
1071                         Com_HexDumpToConsole(buffer, length_received);
1072                 }
1073                 keygen_i = -1;
1074                 SV_UnlockThreadMutex();
1075                 return;
1076         }
1077         if(!qd0_blind_id_finish_private_id_request(pubkeys[keygen_i], p[0], l[0]))
1078         {
1079                 Con_Printf("d0_blind_id_finish_private_id_request failed\n");
1080                 keygen_i = -1;
1081                 SV_UnlockThreadMutex();
1082                 return;
1083         }
1084
1085         // verify the key we just got (just in case)
1086         if(!qd0_blind_id_verify_public_id(pubkeys[keygen_i], &status) || !status)
1087         {
1088                 Con_Printf("d0_blind_id_verify_public_id failed\n");
1089                 keygen_i = -1;
1090                 SV_UnlockThreadMutex();
1091                 return;
1092         }
1093
1094         // we have a valid key now!
1095         // make the rest of crypto.c know that
1096         Con_Printf("Received signature for private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1097         pubkeys_havesig[keygen_i] = true;
1098
1099         // write the key to disk
1100         p[0] = buf;
1101         l[0] = sizeof(buf);
1102         if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1103         {
1104                 Con_Printf("d0_blind_id_write_private_id failed\n");
1105                 keygen_i = -1;
1106                 SV_UnlockThreadMutex();
1107                 return;
1108         }
1109         if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1110         {
1111                 Con_Printf("Crypto_UnParsePack failed\n");
1112                 keygen_i = -1;
1113                 SV_UnlockThreadMutex();
1114                 return;
1115         }
1116
1117         FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1118         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1119         if(!f)
1120         {
1121                 Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1122                 keygen_i = -1;
1123                 SV_UnlockThreadMutex();
1124                 return;
1125         }
1126         FS_Write(f, buf2, buf2size);
1127         FS_Close(f);
1128
1129         Con_Printf("Saved to key_%d.d0si%s\n", keygen_i, sessionid.string);
1130         keygen_i = -1;
1131         SV_UnlockThreadMutex();
1132 }
1133
1134 static void Crypto_KeyGen_f(void)
1135 {
1136         int i;
1137         const char *p[1];
1138         size_t l[1];
1139         static char buf[8192];
1140         static char buf2[8192];
1141         size_t buf2size;
1142         size_t buf2l, buf2pos;
1143         char vabuf[1024];
1144         size_t len2;
1145         qfile_t *f = NULL;
1146
1147         if(!d0_blind_id_dll)
1148         {
1149                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1150                 return;
1151         }
1152         if(Cmd_Argc() != 3)
1153         {
1154                 Con_Printf("usage:\n%s id url\n", Cmd_Argv(0));
1155                 return;
1156         }
1157         SV_LockThreadMutex();
1158         Crypto_LoadKeys();
1159         i = atoi(Cmd_Argv(1));
1160         if(!pubkeys[i])
1161         {
1162                 Con_Printf("there is no public key %d\n", i);
1163                 SV_UnlockThreadMutex();
1164                 return;
1165         }
1166         if(keygen_i >= 0)
1167         {
1168                 Con_Printf("there is already a keygen run on the way\n");
1169                 SV_UnlockThreadMutex();
1170                 return;
1171         }
1172         keygen_i = i;
1173
1174         // how to START the keygenning...
1175         if(pubkeys_havepriv[keygen_i])
1176         {
1177                 if(pubkeys_havesig[keygen_i])
1178                 {
1179                         Con_Printf("there is already a signed private key for %d\n", i);
1180                         keygen_i = -1;
1181                         SV_UnlockThreadMutex();
1182                         return;
1183                 }
1184                 // if we get here, we only need a signature, no new keygen run needed
1185                 Con_Printf("Only need a signature for an existing key...\n");
1186         }
1187         else
1188         {
1189                 // we also need a new ID itself
1190                 if(!qd0_blind_id_generate_private_id_start(pubkeys[keygen_i]))
1191                 {
1192                         Con_Printf("d0_blind_id_start failed\n");
1193                         keygen_i = -1;
1194                         SV_UnlockThreadMutex();
1195                         return;
1196                 }
1197                 // verify the key we just got (just in case)
1198                 if(!qd0_blind_id_verify_private_id(pubkeys[keygen_i]))
1199                 {
1200                         Con_Printf("d0_blind_id_verify_private_id failed\n");
1201                         keygen_i = -1;
1202                         SV_UnlockThreadMutex();
1203                         return;
1204                 }
1205                 // we have a valid key now!
1206                 // make the rest of crypto.c know that
1207                 len2 = FP64_SIZE;
1208                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[keygen_i], pubkeys_priv_fp64[keygen_i], &len2)) // keeps final NUL
1209                 {
1210                         Con_Printf("Generated private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1211                         pubkeys_havepriv[keygen_i] = true;
1212                         strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[keygen_i], pubkeys_fp64[keygen_i]), sizeof(crypto_idstring_buf));
1213                         crypto_idstring = crypto_idstring_buf;
1214                         Crypto_BuildChallengeAppend();
1215                 }
1216                 // write the key to disk
1217                 p[0] = buf;
1218                 l[0] = sizeof(buf);
1219                 if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1220                 {
1221                         Con_Printf("d0_blind_id_write_private_id failed\n");
1222                         keygen_i = -1;
1223                         SV_UnlockThreadMutex();
1224                         return;
1225                 }
1226                 if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1227                 {
1228                         Con_Printf("Crypto_UnParsePack failed\n");
1229                         keygen_i = -1;
1230                         SV_UnlockThreadMutex();
1231                         return;
1232                 }
1233
1234                 FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1235                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1236                 if(!f)
1237                 {
1238                         Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1239                         keygen_i = -1;
1240                         SV_UnlockThreadMutex();
1241                         return;
1242                 }
1243                 FS_Write(f, buf2, buf2size);
1244                 FS_Close(f);
1245
1246                 Con_Printf("Saved unsigned key to key_%d.d0si%s\n", keygen_i, sessionid.string);
1247         }
1248         p[0] = buf;
1249         l[0] = sizeof(buf);
1250         if(!qd0_blind_id_generate_private_id_request(pubkeys[keygen_i], buf, &l[0]))
1251         {
1252                 Con_Printf("d0_blind_id_generate_private_id_request failed\n");
1253                 keygen_i = -1;
1254                 SV_UnlockThreadMutex();
1255                 return;
1256         }
1257         buf2pos = strlen(Cmd_Argv(2));
1258         memcpy(buf2, Cmd_Argv(2), buf2pos);
1259         if(!(buf2l = Crypto_UnParsePack(buf2 + buf2pos, sizeof(buf2) - buf2pos - 1, FOURCC_D0IQ, p, l, 1)))
1260         {
1261                 Con_Printf("Crypto_UnParsePack failed\n");
1262                 keygen_i = -1;
1263                 SV_UnlockThreadMutex();
1264                 return;
1265         }
1266         if(!(buf2l = base64_encode((unsigned char *) (buf2 + buf2pos), buf2l, sizeof(buf2) - buf2pos - 1)))
1267         {
1268                 Con_Printf("base64_encode failed\n");
1269                 keygen_i = -1;
1270                 SV_UnlockThreadMutex();
1271                 return;
1272         }
1273         buf2l += buf2pos;
1274         buf[buf2l] = 0;
1275         if(!Curl_Begin_ToMemory(buf2, 0, (unsigned char *) keygen_buf, sizeof(keygen_buf), Crypto_KeyGen_Finished, NULL))
1276         {
1277                 Con_Printf("curl failed\n");
1278                 keygen_i = -1;
1279                 SV_UnlockThreadMutex();
1280                 return;
1281         }
1282         Con_Printf("Signature generation in progress...\n");
1283         SV_UnlockThreadMutex();
1284 }
1285 // end
1286
1287 // console commands
1288 static void Crypto_Reload_f(void)
1289 {
1290         Crypto_ClearHostKeys();
1291         Crypto_UnloadKeys();
1292         Crypto_LoadKeys();
1293 }
1294
1295 static void Crypto_Keys_f(void)
1296 {
1297         int i;
1298         if(!d0_blind_id_dll)
1299         {
1300                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1301                 return;
1302         }
1303         for(i = 0; i < MAX_PUBKEYS; ++i)
1304         {
1305                 if(pubkeys[i])
1306                 {
1307                         Con_Printf("%2d: public key key_%d.d0pk (fingerprint: %s)\n", i, i, pubkeys_fp64[i]);
1308                         if(pubkeys_havepriv[i])
1309                         {
1310                                 Con_Printf("    private ID key_%d.d0si%s (public key fingerprint: %s)\n", i, sessionid.string, pubkeys_priv_fp64[i]);
1311                                 if(!pubkeys_havesig[i])
1312                                         Con_Printf("    NOTE: this ID has not yet been signed!\n");
1313                         }
1314                 }
1315         }
1316 }
1317
1318 static void Crypto_HostKeys_f(void)
1319 {
1320         int i;
1321         crypto_storedhostkey_t *hk;
1322         char buf[128];
1323
1324         if(!d0_blind_id_dll)
1325         {
1326                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1327                 return;
1328         }
1329         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
1330         {
1331                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hk->next)
1332                 {
1333                         LHNETADDRESS_ToString(&hk->addr, buf, sizeof(buf), 1);
1334                         Con_Printf("%d %s@%.*s %s\n",
1335                                         hk->aeslevel,
1336                                         hk->idfp,
1337                                         crypto_keyfp_recommended_length, pubkeys_fp64[hk->keyid],
1338                                         buf);
1339                 }
1340         }
1341 }
1342
1343 static void Crypto_HostKey_Clear_f(void)
1344 {
1345         lhnetaddress_t addr;
1346         int i;
1347
1348         if(!d0_blind_id_dll)
1349         {
1350                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1351                 return;
1352         }
1353
1354         for(i = 1; i < Cmd_Argc(); ++i)
1355         {
1356                 LHNETADDRESS_FromString(&addr, Cmd_Argv(i), 26000);
1357                 if(Crypto_ClearHostKey(&addr))
1358                 {
1359                         Con_Printf("cleared host key for %s\n", Cmd_Argv(i));
1360                 }
1361         }
1362 }
1363
1364 void Crypto_Init_Commands(void)
1365 {
1366         if(d0_blind_id_dll)
1367         {
1368                 Cmd_AddCommand("crypto_reload", Crypto_Reload_f, "reloads cryptographic keys");
1369                 Cmd_AddCommand("crypto_keygen", Crypto_KeyGen_f, "generates and saves a cryptographic key");
1370                 Cmd_AddCommand("crypto_keys", Crypto_Keys_f, "lists the loaded keys");
1371                 Cmd_AddCommand("crypto_hostkeys", Crypto_HostKeys_f, "lists the cached host keys");
1372                 Cmd_AddCommand("crypto_hostkey_clear", Crypto_HostKey_Clear_f, "clears a cached host key");
1373                 Cvar_RegisterVariable(&crypto_developer);
1374                 if(d0_rijndael_dll)
1375                         Cvar_RegisterVariable(&crypto_aeslevel);
1376                 else
1377                         crypto_aeslevel.integer = 0; // make sure
1378                 Cvar_RegisterVariable(&crypto_servercpupercent);
1379                 Cvar_RegisterVariable(&crypto_servercpumaxtime);
1380                 Cvar_RegisterVariable(&crypto_servercpudebug);
1381         }
1382 }
1383 // end
1384
1385 // AES encryption
1386 static void aescpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1387 {
1388         const unsigned char *xorpos = iv;
1389         unsigned char xorbuf[16];
1390         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1391         size_t i;
1392         qd0_rijndael_setup_encrypt(rk, key, DHKEY_SIZE * 8);
1393         while(len > 16)
1394         {
1395                 for(i = 0; i < 16; ++i)
1396                         xorbuf[i] = src[i] ^ xorpos[i];
1397                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1398                 xorpos = dst;
1399                 len -= 16;
1400                 src += 16;
1401                 dst += 16;
1402         }
1403         if(len > 0)
1404         {
1405                 for(i = 0; i < len; ++i)
1406                         xorbuf[i] = src[i] ^ xorpos[i];
1407                 for(; i < 16; ++i)
1408                         xorbuf[i] = xorpos[i];
1409                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1410         }
1411 }
1412 static void seacpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1413 {
1414         const unsigned char *xorpos = iv;
1415         unsigned char xorbuf[16];
1416         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1417         size_t i;
1418         qd0_rijndael_setup_decrypt(rk, key, DHKEY_SIZE * 8);
1419         while(len > 16)
1420         {
1421                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1422                 for(i = 0; i < 16; ++i)
1423                         dst[i] = xorbuf[i] ^ xorpos[i];
1424                 xorpos = src;
1425                 len -= 16;
1426                 src += 16;
1427                 dst += 16;
1428         }
1429         if(len > 0)
1430         {
1431                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1432                 for(i = 0; i < len; ++i)
1433                         dst[i] = xorbuf[i] ^ xorpos[i];
1434         }
1435 }
1436
1437 // NOTE: we MUST avoid the following begins of the packet:
1438 //   1. 0xFF, 0xFF, 0xFF, 0xFF
1439 //   2. 0x80, 0x00, length/256, length%256
1440 // this luckily does NOT affect AES mode, where the first byte always is in the range from 0x00 to 0x0F
1441 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)
1442 {
1443         unsigned char h[32];
1444         int i;
1445         if(crypto->authenticated)
1446         {
1447                 if(crypto->use_aes)
1448                 {
1449                         // AES packet = 1 byte length overhead, 15 bytes from HMAC-SHA-256, data, 0..15 bytes padding
1450                         // 15 bytes HMAC-SHA-256 (112bit) suffice as the attacker can't do more than forge a random-looking packet
1451                         // HMAC is needed to not leak information about packet content
1452                         if(developer_networking.integer)
1453                         {
1454                                 Con_Print("To be encrypted:\n");
1455                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1456                         }
1457                         if(len_src + 32 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1458                         {
1459                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1460                                 return NULL;
1461                         }
1462                         *len_dst = ((len_src + 15) / 16) * 16 + 16; // add 16 for HMAC, then round to 16-size for AES
1463                         ((unsigned char *) data_dst)[0] = *len_dst - len_src;
1464                         memcpy(((unsigned char *) data_dst)+1, h, 15);
1465                         aescpy(crypto->dhkey, (const unsigned char *) data_dst, ((unsigned char *) data_dst) + 16, (const unsigned char *) data_src, len_src);
1466                         //                    IV                                dst                                src                               len
1467                 }
1468                 else
1469                 {
1470                         // HMAC packet = 16 bytes HMAC-SHA-256 (truncated to 128 bits), data
1471                         if(len_src + 16 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1472                         {
1473                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1474                                 return NULL;
1475                         }
1476                         *len_dst = len_src + 16;
1477                         memcpy(data_dst, h, 16);
1478                         memcpy(((unsigned char *) data_dst) + 16, (unsigned char *) data_src, len_src);
1479
1480                         // handle the "avoid" conditions:
1481                         i = BuffBigLong((unsigned char *) data_dst);
1482                         if(
1483                                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1484                                 ||
1485                                 (i == (int)0x80000000 + (int)*len_dst) // avoid NQ control packet
1486                         )
1487                                 *(unsigned char *)data_dst ^= 0x80; // this will ALWAYS fix it
1488                 }
1489                 return data_dst;
1490         }
1491         else
1492         {
1493                 *len_dst = len_src;
1494                 return data_src;
1495         }
1496 }
1497
1498 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)
1499 {
1500         unsigned char h[32];
1501         int i;
1502
1503         // silently handle non-crypto packets
1504         i = BuffBigLong((unsigned char *) data_src);
1505         if(
1506                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1507                 ||
1508                 (i == (int)0x80000000 + (int)len_src) // avoid NQ control packet
1509         )
1510                 return NULL;
1511
1512         if(crypto->authenticated)
1513         {
1514                 if(crypto->use_aes)
1515                 {
1516                         if(len_src < 16 || ((len_src - 16) % 16))
1517                         {
1518                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1519                                 return NULL;
1520                         }
1521                         *len_dst = len_src - ((unsigned char *) data_src)[0];
1522                         if(len < *len_dst || *len_dst > len_src - 16)
1523                         {
1524                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1525                                 return NULL;
1526                         }
1527                         seacpy(crypto->dhkey, (unsigned char *) data_src, (unsigned char *) data_dst, ((const unsigned char *) data_src) + 16, *len_dst);
1528                         //                    IV                          dst                         src                                      len
1529                         if(!HMAC_SHA256_32BYTES(h, (const unsigned char *) data_dst, *len_dst, crypto->dhkey, DHKEY_SIZE))
1530                         {
1531                                 Con_Printf("HMAC fail\n");
1532                                 return NULL;
1533                         }
1534                         if(memcmp(((const unsigned char *) data_src)+1, h, 15)) // ignore first byte, used for length
1535                         {
1536                                 Con_Printf("HMAC mismatch\n");
1537                                 return NULL;
1538                         }
1539                         if(developer_networking.integer)
1540                         {
1541                                 Con_Print("Decrypted:\n");
1542                                 Com_HexDumpToConsole((const unsigned char *) data_dst, *len_dst);
1543                         }
1544                         return data_dst; // no need to copy
1545                 }
1546                 else
1547                 {
1548                         if(len_src < 16)
1549                         {
1550                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1551                                 return NULL;
1552                         }
1553                         *len_dst = len_src - 16;
1554                         if(len < *len_dst)
1555                         {
1556                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1557                                 return NULL;
1558                         }
1559                         //memcpy(data_dst, data_src + 16, *len_dst);
1560                         if(!HMAC_SHA256_32BYTES(h, ((const unsigned char *) data_src) + 16, *len_dst, crypto->dhkey, DHKEY_SIZE))
1561                         {
1562                                 Con_Printf("HMAC fail\n");
1563                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1564                                 return NULL;
1565                         }
1566
1567                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1568                         {
1569                                 // undo the "avoid conditions"
1570                                 if(
1571                                                 (i == (int)0x7FFFFFFF) // avoided QW control packet
1572                                                 ||
1573                                                 (i == (int)0x00000000 + (int)len_src) // avoided NQ control packet
1574                                   )
1575                                 {
1576                                         // do the avoidance on the hash too
1577                                         h[0] ^= 0x80;
1578                                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1579                                         {
1580                                                 Con_Printf("HMAC mismatch\n");
1581                                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1582                                                 return NULL;
1583                                         }
1584                                 }
1585                                 else
1586                                 {
1587                                         Con_Printf("HMAC mismatch\n");
1588                                         Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1589                                         return NULL;
1590                                 }
1591                         }
1592                         return ((const unsigned char *) data_src) + 16; // no need to copy, so data_dst is not used
1593                 }
1594         }
1595         else
1596         {
1597                 *len_dst = len_src;
1598                 return data_src;
1599         }
1600 }
1601 // end
1602
1603 const char *Crypto_GetInfoResponseDataString(void)
1604 {
1605         crypto_idstring_buf[0] = '0' + crypto_aeslevel.integer;
1606         return crypto_idstring;
1607 }
1608
1609 // network protocol
1610 qboolean Crypto_ServerAppendToChallenge(const char *data_in, size_t len_in, char *data_out, size_t *len_out, size_t maxlen_out)
1611 {
1612         // cheap op, all is precomputed
1613         if(!d0_blind_id_dll)
1614                 return false; // no support
1615         // append challenge
1616         if(maxlen_out <= *len_out + challenge_append_length)
1617                 return false;
1618         memcpy(data_out + *len_out, challenge_append, challenge_append_length);
1619         *len_out += challenge_append_length;
1620         return false;
1621 }
1622
1623 static int Crypto_ServerError(char *data_out, size_t *len_out, const char *msg, const char *msg_client)
1624 {
1625         if(!msg_client)
1626                 msg_client = msg;
1627         Con_DPrintf("rejecting client: %s\n", msg);
1628         if(*msg_client)
1629                 dpsnprintf(data_out, *len_out, "reject %s", msg_client);
1630         *len_out = strlen(data_out);
1631         return CRYPTO_DISCARD;
1632 }
1633
1634 static int Crypto_SoftServerError(char *data_out, size_t *len_out, const char *msg)
1635 {
1636         *len_out = 0;
1637         Con_DPrintf("%s\n", msg);
1638         return CRYPTO_DISCARD;
1639 }
1640
1641 static int Crypto_ServerParsePacket_Internal(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1642 {
1643         // if "connect": reject if in the middle of crypto handshake
1644         crypto_t *crypto = NULL;
1645         char *data_out_p = data_out;
1646         const char *string = data_in;
1647         int aeslevel;
1648         D0_BOOL aes;
1649         D0_BOOL status;
1650         char infostringvalue[MAX_INPUTLINE];
1651         char vabuf[1024];
1652
1653         if(!d0_blind_id_dll)
1654                 return CRYPTO_NOMATCH; // no support
1655
1656         if (len_in > 8 && !memcmp(string, "connect\\", 8) && d0_rijndael_dll && crypto_aeslevel.integer >= 3)
1657         {
1658                 const char *s;
1659                 int i;
1660                 // sorry, we have to verify the challenge here to not reflect network spam
1661
1662                 if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1663                         return CRYPTO_NOMATCH; // will be later accepted if encryption was set up
1664                 // validate the challenge
1665                 for (i = 0;i < MAX_CHALLENGES;i++)
1666                         if(challenge[i].time > 0)
1667                                 if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1668                                         break;
1669                 // if the challenge is not recognized, drop the packet
1670                 if (i == MAX_CHALLENGES) // challenge mismatch is silent
1671                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1672
1673                 crypto = Crypto_ServerFindInstance(peeraddress, false);
1674                 if(!crypto || !crypto->authenticated)
1675                         return Crypto_ServerError(data_out, len_out, "This server requires authentication and encryption to be supported by your client", NULL);
1676         }
1677         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && ((LHNETADDRESS_GetAddressType(peeraddress) == LHNETADDRESSTYPE_LOOP) || sv_public.integer > -3))
1678         {
1679                 const char *cnt, *s, *p;
1680                 int id;
1681                 int clientid = -1, serverid = -1;
1682                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
1683                 id = (cnt ? atoi(cnt) : -1);
1684                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1685                 if(!cnt)
1686                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1687                 GetUntilNul(&data_in, &len_in);
1688                 if(!data_in)
1689                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1690                 if(!strcmp(cnt, "0"))
1691                 {
1692                         int i;
1693                         if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1694                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1695                         // validate the challenge
1696                         for (i = 0;i < MAX_CHALLENGES;i++)
1697                                 if(challenge[i].time > 0)
1698                                         if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1699                                                 break;
1700                         // if the challenge is not recognized, drop the packet
1701                         if (i == MAX_CHALLENGES) // challenge mismatch is silent
1702                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1703
1704                         if (!(s = InfoString_GetValue(string + 4, "aeslevel", infostringvalue, sizeof(infostringvalue))))
1705                                 aeslevel = 0; // not supported
1706                         else
1707                                 aeslevel = bound(0, atoi(s), 3);
1708                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
1709                         {
1710                                 default: // dummy, never happens, but to make gcc happy...
1711                                 case 0:
1712                                         if(aeslevel >= 3)
1713                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
1714                                         aes = false;
1715                                         break;
1716                                 case 1:
1717                                         aes = (aeslevel >= 2);
1718                                         break;
1719                                 case 2:
1720                                         aes = (aeslevel >= 1);
1721                                         break;
1722                                 case 3:
1723                                         if(aeslevel <= 0)
1724                                                 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);
1725                                         aes = true;
1726                                         break;
1727                         }
1728
1729                         p = GetUntilNul(&data_in, &len_in);
1730                         if(p && *p)
1731                         {
1732                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1733                                 {
1734                                         if(pubkeys[i])
1735                                                 if(!strcmp(p, pubkeys_fp64[i]))
1736                                                         if(pubkeys_havepriv[i])
1737                                                                 if(serverid < 0)
1738                                                                         serverid = i;
1739                                 }
1740                                 if(serverid < 0)
1741                                         return Crypto_ServerError(data_out, len_out, "Invalid server key", NULL);
1742                         }
1743                         p = GetUntilNul(&data_in, &len_in);
1744                         if(p && *p)
1745                         {
1746                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1747                                 {
1748                                         if(pubkeys[i])
1749                                                 if(!strcmp(p, pubkeys_fp64[i]))
1750                                                         if(clientid < 0)
1751                                                                 clientid = i;
1752                                 }
1753                                 if(clientid < 0)
1754                                         return Crypto_ServerError(data_out, len_out, "Invalid client key", NULL);
1755                         }
1756
1757                         crypto = Crypto_ServerFindInstance(peeraddress, true);
1758                         if(!crypto)
1759                                 return Crypto_ServerError(data_out, len_out, "Could not create a crypto connect instance", NULL);
1760                         MAKE_CDATA;
1761                         CDATA->cdata_id = id;
1762                         CDATA->s = serverid;
1763                         CDATA->c = clientid;
1764                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
1765                         CDATA->challenge[0] = 0;
1766                         crypto->client_keyfp[0] = 0;
1767                         crypto->client_idfp[0] = 0;
1768                         crypto->server_keyfp[0] = 0;
1769                         crypto->server_idfp[0] = 0;
1770                         crypto->use_aes = aes != 0;
1771
1772                         if(CDATA->s >= 0)
1773                         {
1774                                 // I am the server, and my key is ok... so let's set server_keyfp and server_idfp
1775                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
1776                                 strlcpy(crypto->server_idfp, pubkeys_priv_fp64[CDATA->s], sizeof(crypto->server_idfp));
1777
1778                                 if(!CDATA->id)
1779                                         CDATA->id = qd0_blind_id_new();
1780                                 if(!CDATA->id)
1781                                 {
1782                                         CLEAR_CDATA;
1783                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1784                                 }
1785                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
1786                                 {
1787                                         CLEAR_CDATA;
1788                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1789                                 }
1790                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\1\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1791                                 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
1792                                 {
1793                                         CLEAR_CDATA;
1794                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed", "Internal error");
1795                                 }
1796                                 CDATA->next_step = 2;
1797                                 data_out_p += *len_out;
1798                                 *len_out = data_out_p - data_out;
1799                                 return CRYPTO_DISCARD;
1800                         }
1801                         else if(CDATA->c >= 0)
1802                         {
1803                                 if(!CDATA->id)
1804                                         CDATA->id = qd0_blind_id_new();
1805                                 if(!CDATA->id)
1806                                 {
1807                                         CLEAR_CDATA;
1808                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1809                                 }
1810                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1811                                 {
1812                                         CLEAR_CDATA;
1813                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1814                                 }
1815                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1816                                 if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1817                                 {
1818                                         CLEAR_CDATA;
1819                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1820                                 }
1821                                 CDATA->next_step = 6;
1822                                 data_out_p += *len_out;
1823                                 *len_out = data_out_p - data_out;
1824                                 return CRYPTO_DISCARD;
1825                         }
1826                         else
1827                         {
1828                                 CLEAR_CDATA;
1829                                 return Crypto_ServerError(data_out, len_out, "Missing client and server key", NULL);
1830                         }
1831                 }
1832                 else if(!strcmp(cnt, "2"))
1833                 {
1834                         size_t fpbuflen;
1835                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1836                         if(!crypto)
1837                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1838                         if(id >= 0)
1839                                 if(CDATA->cdata_id != id)
1840                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1841                         if(CDATA->next_step != 2)
1842                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1843
1844                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\3\\id\\%d", CDATA->cdata_id));
1845                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
1846                         {
1847                                 CLEAR_CDATA;
1848                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed", "Internal error");
1849                         }
1850                         fpbuflen = DHKEY_SIZE;
1851                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
1852                         {
1853                                 CLEAR_CDATA;
1854                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1855                         }
1856                         if(CDATA->c >= 0)
1857                         {
1858                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1859                                 {
1860                                         CLEAR_CDATA;
1861                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1862                                 }
1863                                 CDATA->next_step = 4;
1864                         }
1865                         else
1866                         {
1867                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1868                                 crypto->authenticated = true;
1869                                 CDATA->next_step = 0;
1870                         }
1871                         data_out_p += *len_out;
1872                         *len_out = data_out_p - data_out;
1873                         return CRYPTO_DISCARD;
1874                 }
1875                 else if(!strcmp(cnt, "4"))
1876                 {
1877                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1878                         if(!crypto)
1879                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1880                         if(id >= 0)
1881                                 if(CDATA->cdata_id != id)
1882                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1883                         if(CDATA->next_step != 4)
1884                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1885                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d", CDATA->cdata_id));
1886                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1887                         {
1888                                 CLEAR_CDATA;
1889                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1890                         }
1891                         CDATA->next_step = 6;
1892                         data_out_p += *len_out;
1893                         *len_out = data_out_p - data_out;
1894                         return CRYPTO_DISCARD;
1895                 }
1896                 else if(!strcmp(cnt, "6"))
1897                 {
1898                         static char msgbuf[32];
1899                         size_t msgbuflen = sizeof(msgbuf);
1900                         size_t fpbuflen;
1901                         int i;
1902                         unsigned char dhkey[DHKEY_SIZE];
1903                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1904                         if(!crypto)
1905                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1906                         if(id >= 0)
1907                                 if(CDATA->cdata_id != id)
1908                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1909                         if(CDATA->next_step != 6)
1910                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1911
1912                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
1913                         {
1914                                 CLEAR_CDATA;
1915                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (authentication error)", "Authentication error");
1916                         }
1917                         if(status)
1918                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
1919                         else
1920                                 crypto->client_keyfp[0] = 0;
1921                         memset(crypto->client_idfp, 0, sizeof(crypto->client_idfp));
1922                         fpbuflen = FP64_SIZE;
1923                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->client_idfp, &fpbuflen))
1924                         {
1925                                 CLEAR_CDATA;
1926                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed", "Internal error");
1927                         }
1928                         fpbuflen = DHKEY_SIZE;
1929                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
1930                         {
1931                                 CLEAR_CDATA;
1932                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1933                         }
1934                         // XOR the two DH keys together to make one
1935                         for(i = 0; i < DHKEY_SIZE; ++i)
1936                                 crypto->dhkey[i] ^= dhkey[i];
1937
1938                         // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1939                         crypto->authenticated = true;
1940                         CDATA->next_step = 0;
1941                         // send a challenge-less challenge
1942                         PutWithNul(&data_out_p, len_out, "challenge ");
1943                         *len_out = data_out_p - data_out;
1944                         --*len_out; // remove NUL terminator
1945                         return CRYPTO_MATCH;
1946                 }
1947                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1948         }
1949         return CRYPTO_NOMATCH;
1950 }
1951
1952 int Crypto_ServerParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1953 {
1954         int ret;
1955         double t = 0;
1956         static double complain_time = 0;
1957         const char *cnt;
1958         qboolean do_time = false;
1959         qboolean do_reject = false;
1960         char infostringvalue[MAX_INPUTLINE];
1961         if(crypto_servercpupercent.value > 0 || crypto_servercpumaxtime.value > 0)
1962                 if(len_in > 5 && !memcmp(data_in, "d0pk\\", 5))
1963                 {
1964                         do_time = true;
1965                         cnt = InfoString_GetValue(data_in + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1966                         if(cnt)
1967                                 if(!strcmp(cnt, "0"))
1968                                         do_reject = true;
1969                 }
1970         if(do_time)
1971         {
1972                 // check if we may perform crypto...
1973                 if(crypto_servercpupercent.value > 0)
1974                 {
1975                         crypto_servercpu_accumulator += (realtime - crypto_servercpu_lastrealtime) * crypto_servercpupercent.value * 0.01;
1976                         if(crypto_servercpumaxtime.value)
1977                                 if(crypto_servercpu_accumulator > crypto_servercpumaxtime.value)
1978                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
1979                 }
1980                 else
1981                 {
1982                         if(crypto_servercpumaxtime.value > 0)
1983                                 if(realtime != crypto_servercpu_lastrealtime)
1984                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
1985                 }
1986                 crypto_servercpu_lastrealtime = realtime;
1987                 if(do_reject && crypto_servercpu_accumulator < 0)
1988                 {
1989                         if(realtime > complain_time + 5)
1990                                 Con_Printf("crypto: cannot perform requested crypto operations; denial service attack or crypto_servercpupercent/crypto_servercpumaxtime are too low\n");
1991                         *len_out = 0;
1992                         return CRYPTO_DISCARD;
1993                 }
1994                 t = Sys_DirtyTime();
1995         }
1996         ret = Crypto_ServerParsePacket_Internal(data_in, len_in, data_out, len_out, peeraddress);
1997         if(do_time)
1998         {
1999                 t = Sys_DirtyTime() - t;if (t < 0.0) t = 0.0; // dirtytime can step backwards
2000                 if(crypto_servercpudebug.integer)
2001                         Con_Printf("crypto: accumulator was %.1f ms, used %.1f ms for crypto, ", crypto_servercpu_accumulator * 1000, t * 1000);
2002                 crypto_servercpu_accumulator -= t;
2003                 if(crypto_servercpudebug.integer)
2004                         Con_Printf("is %.1f ms\n", crypto_servercpu_accumulator * 1000);
2005         }
2006         return ret;
2007 }
2008
2009 static int Crypto_ClientError(char *data_out, size_t *len_out, const char *msg)
2010 {
2011         dpsnprintf(data_out, *len_out, "reject %s", msg);
2012         *len_out = strlen(data_out);
2013         return CRYPTO_REPLACE;
2014 }
2015
2016 static int Crypto_SoftClientError(char *data_out, size_t *len_out, const char *msg)
2017 {
2018         *len_out = 0;
2019         Con_Printf("%s\n", msg);
2020         return CRYPTO_DISCARD;
2021 }
2022
2023 int Crypto_ClientParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
2024 {
2025         crypto_t *crypto = &cls.crypto;
2026         const char *string = data_in;
2027         const char *s;
2028         D0_BOOL aes;
2029         char *data_out_p = data_out;
2030         D0_BOOL status;
2031         char infostringvalue[MAX_INPUTLINE];
2032         char vabuf[1024];
2033
2034         if(!d0_blind_id_dll)
2035                 return CRYPTO_NOMATCH; // no support
2036
2037         // if "challenge": verify challenge, and discard message, send next crypto protocol message instead
2038         // otherwise, just handle actual protocol messages
2039
2040         if (len_in == 6 && !memcmp(string, "accept", 6) && cls.connect_trying && d0_rijndael_dll)
2041         {
2042                 int wantserverid = -1;
2043                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2044                 if(!crypto || !crypto->authenticated) // we ALSO get here if we are using an encrypted connection, so let's rule this out
2045                 {
2046                         if(wantserverid >= 0)
2047                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2048                         if(crypto_aeslevel.integer >= 3)
2049                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2050                 }
2051                 return CRYPTO_NOMATCH;
2052         }
2053         else if (len_in >= 1 && string[0] == 'j' && cls.connect_trying && d0_rijndael_dll)
2054         {
2055                 int wantserverid = -1;
2056                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2057                 //if(!crypto || !crypto->authenticated)
2058                 {
2059                         if(wantserverid >= 0)
2060                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2061                         if(crypto_aeslevel.integer >= 3)
2062                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2063                 }
2064                 return CRYPTO_NOMATCH;
2065         }
2066         else if (len_in >= 5 && BuffLittleLong((unsigned char *) string) == ((int)NETFLAG_CTL | (int)len_in))
2067         {
2068                 int wantserverid = -1;
2069
2070                 // these three are harmless
2071                 if(string[4] == CCREP_SERVER_INFO)
2072                         return CRYPTO_NOMATCH;
2073                 if(string[4] == CCREP_PLAYER_INFO)
2074                         return CRYPTO_NOMATCH;
2075                 if(string[4] == CCREP_RULE_INFO)
2076                         return CRYPTO_NOMATCH;
2077
2078                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2079                 //if(!crypto || !crypto->authenticated)
2080                 {
2081                         if(wantserverid >= 0)
2082                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2083                         if(crypto_aeslevel.integer >= 3)
2084                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2085                 }
2086                 return CRYPTO_NOMATCH;
2087         }
2088         else if (len_in >= 13 && !memcmp(string, "infoResponse\x0A", 13))
2089         {
2090                 s = InfoString_GetValue(string + 13, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2091                 if(s)
2092                         Crypto_StoreHostKey(peeraddress, s, true);
2093                 return CRYPTO_NOMATCH;
2094         }
2095         else if (len_in >= 15 && !memcmp(string, "statusResponse\x0A", 15))
2096         {
2097                 char save = 0;
2098                 const char *p;
2099                 p = strchr(string + 15, '\n');
2100                 if(p)
2101                 {
2102                         save = *p;
2103                         * (char *) p = 0; // cut off the string there
2104                 }
2105                 s = InfoString_GetValue(string + 15, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2106                 if(s)
2107                         Crypto_StoreHostKey(peeraddress, s, true);
2108                 if(p)
2109                 {
2110                         * (char *) p = save;
2111                         // invoking those nasal demons again (do not run this on the DS9k)
2112                 }
2113                 return CRYPTO_NOMATCH;
2114         }
2115         else if(len_in > 10 && !memcmp(string, "challenge ", 10) && cls.connect_trying)
2116         {
2117                 const char *vlen_blind_id_ptr = NULL;
2118                 size_t len_blind_id_ptr = 0;
2119                 unsigned long k, v;
2120                 const char *challenge = data_in + 10;
2121                 const char *p;
2122                 int i;
2123                 int clientid = -1, serverid = -1, wantserverid = -1;
2124                 qboolean server_can_auth = true;
2125                 char wantserver_idfp[FP64_SIZE+1];
2126                 int wantserver_aeslevel;
2127
2128                 // if we have a stored host key for the server, assume serverid to already be selected!
2129                 // (the loop will refuse to overwrite this one then)
2130                 wantserver_idfp[0] = 0;
2131                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, wantserver_idfp, sizeof(wantserver_idfp), &wantserver_aeslevel);
2132                 // requirement: wantserver_idfp is a full ID if wantserverid set
2133
2134                 // if we leave, we have to consider the connection
2135                 // unauthenticated; NOTE: this may be faked by a clever
2136                 // attacker to force an unauthenticated connection; so we have
2137                 // a safeguard check in place when encryption is required too
2138                 // in place, or when authentication is required by the server
2139                 crypto->authenticated = false;
2140
2141                 GetUntilNul(&data_in, &len_in);
2142                 if(!data_in)
2143                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present") :
2144                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2145                                 CRYPTO_NOMATCH;
2146
2147                 // FTEQW extension protocol
2148                 while(len_in >= 8)
2149                 {
2150                         k = Crypto_LittleLong(data_in);
2151                         v = Crypto_LittleLong(data_in + 4);
2152                         data_in += 8;
2153                         len_in -= 8;
2154                         switch(k)
2155                         {
2156                                 case PROTOCOL_VLEN:
2157                                         if(len_in >= 4 + v)
2158                                         {
2159                                                 k = Crypto_LittleLong(data_in);
2160                                                 data_in += 4;
2161                                                 len_in -= 4;
2162                                                 switch(k)
2163                                                 {
2164                                                         case PROTOCOL_D0_BLIND_ID:
2165                                                                 vlen_blind_id_ptr = data_in;
2166                                                                 len_blind_id_ptr = v;
2167                                                                 break;
2168                                                 }
2169                                                 data_in += v;
2170                                                 len_in -= v;
2171                                         }
2172                                         break;
2173                                 default:
2174                                         break;
2175                         }
2176                 }
2177
2178                 if(!vlen_blind_id_ptr)
2179                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though authentication is required") :
2180                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2181                                 CRYPTO_NOMATCH;
2182
2183                 data_in = vlen_blind_id_ptr;
2184                 len_in = len_blind_id_ptr;
2185
2186                 // parse fingerprints
2187                 //   once we found a fingerprint we can auth to (ANY), select it as clientfp
2188                 //   once we found a fingerprint in the first list that we know, select it as serverfp
2189
2190                 for(;;)
2191                 {
2192                         p = GetUntilNul(&data_in, &len_in);
2193                         if(!p)
2194                                 break;
2195                         if(!*p)
2196                         {
2197                                 if(!server_can_auth)
2198                                         break; // other protocol message may follow
2199                                 server_can_auth = false;
2200                                 if(clientid >= 0)
2201                                         break;
2202                                 continue;
2203                         }
2204                         for(i = 0; i < MAX_PUBKEYS; ++i)
2205                         {
2206                                 if(pubkeys[i])
2207                                 if(!strcmp(p, pubkeys_fp64[i]))
2208                                 {
2209                                         if(pubkeys_havepriv[i])
2210                                                 if(clientid < 0)
2211                                                         clientid = i;
2212                                         if(server_can_auth)
2213                                                 if(serverid < 0)
2214                                                         if(wantserverid < 0 || i == wantserverid)
2215                                                                 serverid = i;
2216                                 }
2217                         }
2218                         if(clientid >= 0 && serverid >= 0)
2219                                 break;
2220                 }
2221
2222                 // if stored host key is not found:
2223                 if(wantserverid >= 0 && serverid < 0)
2224                         return Crypto_ClientError(data_out, len_out, "Server CA does not match stored host key, refusing to connect");
2225
2226                 if(serverid >= 0 || clientid >= 0)
2227                 {
2228                         // TODO at this point, fill clientside crypto struct!
2229                         MAKE_CDATA;
2230                         CDATA->cdata_id = ++cdata_id;
2231                         CDATA->s = serverid;
2232                         CDATA->c = clientid;
2233                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
2234                         strlcpy(CDATA->challenge, challenge, sizeof(CDATA->challenge));
2235                         crypto->client_keyfp[0] = 0;
2236                         crypto->client_idfp[0] = 0;
2237                         crypto->server_keyfp[0] = 0;
2238                         crypto->server_idfp[0] = 0;
2239                         memcpy(CDATA->wantserver_idfp, wantserver_idfp, sizeof(crypto->server_idfp));
2240
2241                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2242                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
2243                         {
2244                                 default: // dummy, never happens, but to make gcc happy...
2245                                 case 0:
2246                                         if(wantserver_aeslevel >= 3)
2247                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
2248                                         CDATA->wantserver_aes = false;
2249                                         break;
2250                                 case 1:
2251                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 2);
2252                                         break;
2253                                 case 2:
2254                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 1);
2255                                         break;
2256                                 case 3:
2257                                         if(wantserver_aeslevel <= 0)
2258                                                 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);
2259                                         CDATA->wantserver_aes = true;
2260                                         break;
2261                         }
2262
2263                         // build outgoing message
2264                         // append regular stuff
2265                         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));
2266                         PutWithNul(&data_out_p, len_out, serverid >= 0 ? pubkeys_fp64[serverid] : "");
2267                         PutWithNul(&data_out_p, len_out, clientid >= 0 ? pubkeys_fp64[clientid] : "");
2268
2269                         if(clientid >= 0)
2270                         {
2271                                 // I am the client, and my key is ok... so let's set client_keyfp and client_idfp
2272                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
2273                                 strlcpy(crypto->client_idfp, pubkeys_priv_fp64[CDATA->c], sizeof(crypto->client_idfp));
2274                         }
2275
2276                         if(serverid >= 0)
2277                         {
2278                                 if(!CDATA->id)
2279                                         CDATA->id = qd0_blind_id_new();
2280                                 if(!CDATA->id)
2281                                 {
2282                                         CLEAR_CDATA;
2283                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2284                                 }
2285                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
2286                                 {
2287                                         CLEAR_CDATA;
2288                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2289                                 }
2290                                 CDATA->next_step = 1;
2291                                 *len_out = data_out_p - data_out;
2292                         }
2293                         else if(clientid >= 0)
2294                         {
2295                                 // skip over server auth, perform client auth only
2296                                 if(!CDATA->id)
2297                                         CDATA->id = qd0_blind_id_new();
2298                                 if(!CDATA->id)
2299                                 {
2300                                         CLEAR_CDATA;
2301                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2302                                 }
2303                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2304                                 {
2305                                         CLEAR_CDATA;
2306                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2307                                 }
2308                                 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
2309                                 {
2310                                         CLEAR_CDATA;
2311                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2312                                 }
2313                                 CDATA->next_step = 5;
2314                                 data_out_p += *len_out;
2315                                 *len_out = data_out_p - data_out;
2316                         }
2317                         else
2318                                 *len_out = data_out_p - data_out;
2319
2320                         return CRYPTO_DISCARD;
2321                 }
2322                 else
2323                 {
2324                         if(wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2325                         if(wantserver_aeslevel >= 3)
2326                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption, but neither can authenticate to the other");
2327                         return (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2328                                 CRYPTO_NOMATCH;
2329                 }
2330         }
2331         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && cls.connect_trying)
2332         {
2333                 const char *cnt;
2334                 int id;
2335                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
2336                 id = (cnt ? atoi(cnt) : -1);
2337                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
2338                 if(!cnt)
2339                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without cnt");
2340                 GetUntilNul(&data_in, &len_in);
2341                 if(!data_in)
2342                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without attachment");
2343
2344                 if(!strcmp(cnt, "1"))
2345                 {
2346                         if(id >= 0)
2347                                 if(CDATA->cdata_id != id)
2348                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2349                         if(CDATA->next_step != 1)
2350                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2351
2352                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2353
2354                         if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2355                                 aes = atoi(s);
2356                         else
2357                                 aes = false;
2358                         // we CANNOT toggle the AES status any more!
2359                         // as the server already decided
2360                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2361                         if(!aes && CDATA->wantserver_aes)
2362                         {
2363                                 CLEAR_CDATA;
2364                                 return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2365                         }
2366                         if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2367                         {
2368                                 CLEAR_CDATA;
2369                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2370                         }
2371                         if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2372                         {
2373                                 CLEAR_CDATA;
2374                                 return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2375                         }
2376                         crypto->use_aes = aes != 0;
2377
2378                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\2\\id\\%d", CDATA->cdata_id));
2379                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
2380                         {
2381                                 CLEAR_CDATA;
2382                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed");
2383                         }
2384                         CDATA->next_step = 3;
2385                         data_out_p += *len_out;
2386                         *len_out = data_out_p - data_out;
2387                         return CRYPTO_DISCARD;
2388                 }
2389                 else if(!strcmp(cnt, "3"))
2390                 {
2391                         static char msgbuf[32];
2392                         size_t msgbuflen = sizeof(msgbuf);
2393                         size_t fpbuflen;
2394
2395                         if(id >= 0)
2396                                 if(CDATA->cdata_id != id)
2397                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2398                         if(CDATA->next_step != 3)
2399                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2400
2401                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2402
2403                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
2404                         {
2405                                 CLEAR_CDATA;
2406                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (server authentication error)");
2407                         }
2408                         if(status)
2409                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
2410                         else
2411                                 crypto->server_keyfp[0] = 0;
2412                         memset(crypto->server_idfp, 0, sizeof(crypto->server_idfp));
2413                         fpbuflen = FP64_SIZE;
2414                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->server_idfp, &fpbuflen))
2415                         {
2416                                 CLEAR_CDATA;
2417                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed");
2418                         }
2419                         if(CDATA->wantserver_idfp[0])
2420                         if(memcmp(CDATA->wantserver_idfp, crypto->server_idfp, sizeof(crypto->server_idfp)))
2421                         {
2422                                 CLEAR_CDATA;
2423                                 return Crypto_ClientError(data_out, len_out, "Server ID does not match stored host key, refusing to connect");
2424                         }
2425                         fpbuflen = DHKEY_SIZE;
2426                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
2427                         {
2428                                 CLEAR_CDATA;
2429                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2430                         }
2431
2432                         // cache the server key
2433                         Crypto_StoreHostKey(&cls.connect_address, va(vabuf, sizeof(vabuf), "%d %s@%s", crypto->use_aes ? 1 : 0, crypto->server_idfp, pubkeys_fp64[CDATA->s]), false);
2434
2435                         if(CDATA->c >= 0)
2436                         {
2437                                 // client will auth next
2438                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\4\\id\\%d", CDATA->cdata_id));
2439                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2440                                 {
2441                                         CLEAR_CDATA;
2442                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2443                                 }
2444                                 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
2445                                 {
2446                                         CLEAR_CDATA;
2447                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2448                                 }
2449                                 CDATA->next_step = 5;
2450                                 data_out_p += *len_out;
2451                                 *len_out = data_out_p - data_out;
2452                                 return CRYPTO_DISCARD;
2453                         }
2454                         else
2455                         {
2456                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
2457                                 crypto->authenticated = true;
2458                                 CDATA->next_step = 0;
2459                                 // assume we got the empty challenge to finish the protocol
2460                                 PutWithNul(&data_out_p, len_out, "challenge ");
2461                                 *len_out = data_out_p - data_out;
2462                                 --*len_out; // remove NUL terminator
2463                                 return CRYPTO_REPLACE;
2464                         }
2465                 }
2466                 else if(!strcmp(cnt, "5"))
2467                 {
2468                         size_t fpbuflen;
2469                         unsigned char dhkey[DHKEY_SIZE];
2470                         int i;
2471
2472                         if(id >= 0)
2473                                 if(CDATA->cdata_id != id)
2474                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2475                         if(CDATA->next_step != 5)
2476                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2477
2478                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2479
2480                         if(CDATA->s < 0) // only if server didn't auth
2481                         {
2482                                 if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2483                                         aes = atoi(s);
2484                                 else
2485                                         aes = false;
2486                                 if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2487                                 if(!aes && CDATA->wantserver_aes)
2488                                 {
2489                                         CLEAR_CDATA;
2490                                         return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2491                                 }
2492                                 if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2493                                 {
2494                                         CLEAR_CDATA;
2495                                         return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2496                                 }
2497                                 if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2498                                 {
2499                                         CLEAR_CDATA;
2500                                         return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2501                                 }
2502                                 crypto->use_aes = aes != 0;
2503                         }
2504
2505                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\6\\id\\%d", CDATA->cdata_id));
2506                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
2507                         {
2508                                 CLEAR_CDATA;
2509                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed");
2510                         }
2511                         fpbuflen = DHKEY_SIZE;
2512                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
2513                         {
2514                                 CLEAR_CDATA;
2515                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2516                         }
2517                         // XOR the two DH keys together to make one
2518                         for(i = 0; i < DHKEY_SIZE; ++i)
2519                                 crypto->dhkey[i] ^= dhkey[i];
2520                         // session key is FINISHED! By this, all keys are set up
2521                         crypto->authenticated = true;
2522                         CDATA->next_step = 0;
2523                         data_out_p += *len_out;
2524                         *len_out = data_out_p - data_out;
2525                         return CRYPTO_DISCARD;
2526                 }
2527                 return Crypto_SoftClientError(data_out, len_out, "Got unknown d0_blind_id message from server");
2528         }
2529
2530         return CRYPTO_NOMATCH;
2531 }
2532
2533 size_t Crypto_SignData(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2534 {
2535         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2536                 return 0;
2537         if(!pubkeys_havepriv[keyid])
2538                 return 0;
2539         if(qd0_blind_id_sign_with_private_id_sign(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2540                 return signed_size;
2541         return 0;
2542 }
2543
2544 size_t Crypto_SignDataDetached(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2545 {
2546         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2547                 return 0;
2548         if(!pubkeys_havepriv[keyid])
2549                 return 0;
2550         if(qd0_blind_id_sign_with_private_id_sign_detached(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2551                 return signed_size;
2552         return 0;
2553 }