]> de.git.xonotic.org Git - xonotic/d0_blind_id.git/blobdiff - d0_blind_id.c
on G*nt**, initialized globals seem to be made of fail and crash
[xonotic/d0_blind_id.git] / d0_blind_id.c
index ba7b5b167a46bbe3061e713b6a653b4a13fa3d76..03670532959a4f3b3c8be4230df0985a79855d84 100644 (file)
 #include "sha2.h"
 
 // old "positive" protocol, uses one extra mod_inv in verify stages
-#define D0_BLIND_ID_POSITIVE_PROTOCOL
+// #define D0_BLIND_ID_POSITIVE_PROTOCOL
 
 // our SHA is SHA-256
 #define SHA_DIGESTSIZE 32
-const char *sha(const unsigned char *in, size_t len)
+const unsigned char *sha(unsigned char *h, const unsigned char *in, size_t len)
 {
-       static char h[32];
-       d0_blind_id_util_sha256(h, (const char *) in, len);
+       d0_blind_id_util_sha256((char *) h, (const char *) in, len);
        return h;
 }
 
@@ -97,18 +96,33 @@ struct d0_blind_id_s
        size_t msglen; // message length
 };
 
+//#define CHECKDEBUG
+#ifdef CHECKDEBUG
+#define CHECK(x) do { if(!(x)) { fprintf(stderr, "CHECK FAILED (%s:%d): %s\n", __FILE__, __LINE__, #x); goto fail; } } while(0)
+#define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) { fprintf(stderr, "CHECK FAILED (%s:%d): %s\n", __FILE__, __LINE__, #value); goto fail; } var = val; } while(0)
+#else
 #define CHECK(x) do { if(!(x)) goto fail; } while(0)
 #define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) goto fail; var = val; } while(0)
-#define MPCHECK(x) do { if(!failed) if(!(x)) failed = 1; } while(0)
-#define MPCHECK_ASSIGN(var, value) do { if(!failed) { d0_bignum_t *val; val = value; if(val) var = val; else failed = 1; } } while(0)
+#endif
 
 #define USING(x) if(!(ctx->x)) return 0
 #define REPLACING(x)
 
-static d0_bignum_t *zero, *one, *four, *temp0, *temp1, *temp2, *temp3, *temp4;
+// safe to use
+static d0_bignum_t *zero, *one, *four;
+
+static d0_bignum_t *temp0, *temp1, *temp2, *temp3, *temp4;
+static void *tempmutex = NULL; // hold this mutex when using temp0 to temp4
+#define USINGTEMPS() int locked = 0
+#define LOCKTEMPS() do { if(!locked) d0_lockmutex(tempmutex); locked = 1; } while(0)
+#define UNLOCKTEMPS() do { if(locked) d0_unlockmutex(tempmutex); locked = 0; } while(0);
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void)
 {
+       USINGTEMPS();
+       d0_initfuncs();
+       tempmutex = d0_createmutex();
+       LOCKTEMPS();
        CHECK(d0_bignum_INITIALIZE());
        CHECK_ASSIGN(zero, d0_bignum_int(zero, 0));
        CHECK_ASSIGN(one, d0_bignum_int(one, 1));
@@ -118,13 +132,17 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void)
        CHECK_ASSIGN(temp2, d0_bignum_int(temp2, 0));
        CHECK_ASSIGN(temp3, d0_bignum_int(temp3, 0));
        CHECK_ASSIGN(temp4, d0_bignum_int(temp4, 0));
+       UNLOCKTEMPS();
        return 1;
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
 void d0_blind_id_SHUTDOWN(void)
 {
+       USINGTEMPS();
+       LOCKTEMPS();
        d0_bignum_free(zero);
        d0_bignum_free(one);
        d0_bignum_free(four);
@@ -134,10 +152,13 @@ void d0_blind_id_SHUTDOWN(void)
        d0_bignum_free(temp3);
        d0_bignum_free(temp4);
        d0_bignum_SHUTDOWN();
+       UNLOCKTEMPS();
+       d0_destroymutex(tempmutex);
+       tempmutex = NULL;
 }
 
 // (G-1)/2
-d0_bignum_t *d0_dl_get_order(d0_bignum_t *o, const d0_bignum_t *G)
+static d0_bignum_t *d0_dl_get_order(d0_bignum_t *o, const d0_bignum_t *G)
 {
        CHECK_ASSIGN(o, d0_bignum_sub(o, G, one));
        CHECK(d0_bignum_shl(o, o, -1)); // order o = (G-1)/2
@@ -155,13 +176,15 @@ fail:
        return NULL;
 }
 
-D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G)
+// temps must NOT be locked when calling this
+static D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G)
 {
-       // using: temp0
+       USINGTEMPS(); // using: temp0
        if(size < 16)
                size = 16;
        for(;;)
        {
+               LOCKTEMPS();
                CHECK(d0_bignum_rand_bit_exact(temp0, size-1));
                if(d0_bignum_isprime(temp0, 0) == 0)
                        continue;
@@ -170,16 +193,19 @@ D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G)
                        continue;
                if(d0_bignum_isprime(temp0, 10) == 0) // finish the previous test
                        continue;
+               UNLOCKTEMPS();
                break;
        }
        return 1;
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
-D0_BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum_t *d, d0_bignum_t *n)
+// temps must NOT be locked when calling this
+static D0_BOOL d0_rsa_generate_key(size_t size, d0_blind_id_t *ctx)
 {
-       // uses temp0 to temp4
+       USINGTEMPS(); // uses temp1 to temp4
        int fail = 0;
        int gcdfail = 0;
        int pb = (size + 1)/2;
@@ -188,54 +214,76 @@ D0_BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum
                pb = 8;
        if(qb < 8)
                qb = 8;
+
+       // we use ctx->rsa_d for the first result so that we can unlock temps later
         for (;;)
        {
-               CHECK(d0_bignum_rand_bit_exact(temp0, pb));
-               if(d0_bignum_isprime(temp0, 10) == 0)
+               LOCKTEMPS();
+               CHECK(d0_bignum_rand_bit_exact(ctx->rsa_d, pb));
+               if(d0_bignum_isprime(ctx->rsa_d, 10) == 0)
+               {
+                       UNLOCKTEMPS();
                        continue;
-               CHECK(d0_bignum_sub(temp2, temp0, one));
-               CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, challenge));
+               }
+               CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one));
+               CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, ctx->rsa_e));
                if(!d0_bignum_cmp(temp4, one))
                        break;
                if(++gcdfail == 3)
-                       return 0;
+                       goto fail;
                ++gcdfail;
        }
+       UNLOCKTEMPS();
+
        gcdfail = 0;
         for (;;)
        {
+               LOCKTEMPS();
                CHECK(d0_bignum_rand_bit_exact(temp1, qb));
-               if(!d0_bignum_cmp(temp1, temp0))
+               if(!d0_bignum_cmp(temp1, ctx->rsa_d))
                {
+                       UNLOCKTEMPS();
                        if(++fail == 3)
-                               return 0;
+                               goto fail;
+                       continue;
                }
                fail = 0;
                if(d0_bignum_isprime(temp1, 10) == 0)
+               {
+                       UNLOCKTEMPS();
                        continue;
+               }
                CHECK(d0_bignum_sub(temp3, temp1, one));
-               CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, challenge));
+               CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, ctx->rsa_e));
                if(!d0_bignum_cmp(temp4, one))
+               {
+                       // we do NOT unlock, as we still need temp1 and temp3
                        break;
+               }
+               UNLOCKTEMPS();
                if(++gcdfail == 3)
-                       return 0;
+                       goto fail;
                ++gcdfail;
        }
 
-       // n = temp0*temp1
-       CHECK(d0_bignum_mul(n, temp0, temp1));
+       // ctx->rsa_n = ctx->rsa_d*temp1
+       CHECK(d0_bignum_mul(ctx->rsa_n, ctx->rsa_d, temp1));
 
-       // d = challenge^-1 mod (temp0-1)(temp1-1)
+       // ctx->rsa_d = ctx->rsa_e^-1 mod (ctx->rsa_d-1)(temp1-1)
+       CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); // we can't reuse the value from above because temps were unlocked
        CHECK(d0_bignum_mul(temp0, temp2, temp3));
-       CHECK(d0_bignum_mod_inv(d, challenge, temp0));
+       CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp0));
+       UNLOCKTEMPS();
        return 1;
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
-D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function reject, d0_blind_id_t *ctx, void *pass)
+// temps must NOT be locked when calling this
+static D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function reject, d0_blind_id_t *ctx, void *pass)
 {
-       // uses temp0 to temp4
+       USINGTEMPS(); // uses temp1 to temp4
        int fail = 0;
        int gcdfail = 0;
        int pb = (size + 1)/2;
@@ -244,12 +292,18 @@ D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function rejec
                pb = 8;
        if(qb < 8)
                qb = 8;
+
+       // we use ctx->rsa_d for the first result so that we can unlock temps later
         for (;;)
        {
-               CHECK(d0_bignum_rand_bit_exact(temp0, pb));
-               if(d0_bignum_isprime(temp0, 10) == 0)
+               LOCKTEMPS();
+               CHECK(d0_bignum_rand_bit_exact(ctx->rsa_d, pb));
+               if(d0_bignum_isprime(ctx->rsa_d, 10) == 0)
+               {
+                       UNLOCKTEMPS();
                        continue;
-               CHECK(d0_bignum_sub(temp2, temp0, one));
+               }
+               CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one));
                CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, ctx->rsa_e));
                if(!d0_bignum_cmp(temp4, one))
                        break;
@@ -257,62 +311,81 @@ D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function rejec
                        return 0;
                ++gcdfail;
        }
+       UNLOCKTEMPS();
+
        gcdfail = 0;
         for (;;)
        {
+               LOCKTEMPS();
                CHECK(d0_bignum_rand_bit_exact(temp1, qb));
-               if(!d0_bignum_cmp(temp1, temp0))
+               if(!d0_bignum_cmp(temp1, ctx->rsa_d))
                {
+                       UNLOCKTEMPS();
                        if(++fail == 3)
                                return 0;
+                       continue;
                }
                fail = 0;
 
-               // n = temp0*temp1
-               CHECK(d0_bignum_mul(ctx->rsa_n, temp0, temp1));
+               // n = ctx->rsa_d*temp1
+               CHECK(d0_bignum_mul(ctx->rsa_n, ctx->rsa_d, temp1));
                if(reject(ctx, pass))
+               {
+                       UNLOCKTEMPS();
                        continue;
+               }
 
                if(d0_bignum_isprime(temp1, 10) == 0)
+               {
+                       UNLOCKTEMPS();
                        continue;
+               }
                CHECK(d0_bignum_sub(temp3, temp1, one));
                CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, ctx->rsa_e));
                if(!d0_bignum_cmp(temp4, one))
+               {
+                       // we do NOT unlock, as we still need temp3
                        break;
+               }
+               UNLOCKTEMPS();
                if(++gcdfail == 3)
                        return 0;
                ++gcdfail;
        }
 
-       // ctx->rsa_d = ctx->rsa_e^-1 mod (temp0-1)(temp1-1)
-       CHECK(d0_bignum_mul(temp0, temp2, temp3));
+       // ctx->rsa_d = ctx->rsa_e^-1 mod (ctx->rsa_d-1)(temp1-1)
+       CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); // we can't reuse the value from above because temps were unlocked
+       CHECK(d0_bignum_mul(ctx->rsa_d, temp2, temp3));
        CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp0));
+       UNLOCKTEMPS();
        return 1;
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_longhash_destructive(unsigned char *convbuf, size_t sz, unsigned char *outbuf, size_t outbuflen)
 {
        size_t n, i;
+       char shabuf[32];
 
        n = outbuflen;
        while(n > SHA_DIGESTSIZE)
        {
-               memcpy(outbuf, sha(convbuf, sz), SHA_DIGESTSIZE);
+               memcpy(outbuf, sha(shabuf, convbuf, sz), SHA_DIGESTSIZE);
                outbuf += SHA_DIGESTSIZE;
                n -= SHA_DIGESTSIZE;
                for(i = 0; i < sz; ++i)
                        if(++convbuf[i])
                                break; // stop until no carry
        }
-       memcpy(outbuf, sha(convbuf, sz), n);
+       memcpy(outbuf, sha(shabuf, convbuf, sz), n);
        return 1;
 }
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_longhash_bignum(const d0_bignum_t *in, unsigned char *outbuf, size_t outbuflen)
 {
-       static unsigned char convbuf[1024];
+       unsigned char convbuf[1024];
        size_t sz;
 
        CHECK(d0_bignum_export_unsigned(in, convbuf, sizeof(convbuf)) >= 0);
@@ -377,7 +450,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key_fastreject(d0_bli
        if(reject)
                CHECK(d0_rsa_generate_key_fastreject(k+1, reject, ctx, pass)); // must fit G for sure
        else
-               CHECK(d0_rsa_generate_key(k+1, ctx->rsa_e, ctx->rsa_d, ctx->rsa_n)); // must fit G for sure
+               CHECK(d0_rsa_generate_key(k+1, ctx)); // must fit G for sure
        return 1;
 fail:
        return 0;
@@ -459,9 +532,10 @@ fail:
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
        d0_iobuf_t *out = NULL;
-       static unsigned char convbuf[2048];
+       unsigned char convbuf[2048];
        d0_iobuf_t *conv = NULL;
        size_t sz, n;
+       char shabuf[32];
 
        USING(rsa_n); USING(rsa_e);
 
@@ -476,7 +550,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_key(const d0_blin
        n = (*outbuflen / 4) * 3;
        if(n > SHA_DIGESTSIZE)
                n = SHA_DIGESTSIZE;
-       CHECK(d0_iobuf_write_raw(out, sha(convbuf, sz), n) == n);
+       CHECK(d0_iobuf_write_raw(out, sha(shabuf, convbuf, sz), n) == n);
        CHECK(d0_iobuf_conv_base64_out(out));
 
        return d0_iobuf_close(out, outbuflen);
@@ -532,27 +606,30 @@ fail:
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx)
 {
-       // temps: temp0 = order
+       USINGTEMPS(); // temps: temp0 = order
        USING(schnorr_G);
        REPLACING(schnorr_s); REPLACING(schnorr_g_to_s);
 
+       LOCKTEMPS();
        CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
        CHECK_ASSIGN(ctx->schnorr_s, d0_bignum_rand_range(ctx->schnorr_s, zero, temp0));
        CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_bignum_mod_pow(ctx->schnorr_g_to_s, four, ctx->schnorr_s, ctx->schnorr_G));
        CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_bignum_zero(ctx->schnorr_H_g_to_s_signature));
+       UNLOCKTEMPS();
        return 1;
 
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
        d0_iobuf_t *out = NULL;
-       static unsigned char shabuf[2048];
+       unsigned char hashbuf[2048];
        size_t sz;
 
-       // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge
+       USINGTEMPS(); // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge
        USING(rsa_n); USING(rsa_e); USING(schnorr_g_to_s);
        REPLACING(rsa_blind_signature_camouflage);
 
@@ -562,19 +639,22 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_request(d0_blind_i
        CHECK(d0_bignum_mod_pow(temp0, ctx->rsa_blind_signature_camouflage, ctx->rsa_e, ctx->rsa_n));
 
        // we will actually sign HA(4^s) to prevent a malleability attack!
+       LOCKTEMPS();
        CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s));
        sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting"
-       if(sz > sizeof(shabuf))
-               sz = sizeof(shabuf);
-       CHECK(d0_longhash_bignum(temp2, shabuf, sz));
-       CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz));
+       if(sz > sizeof(hashbuf))
+               sz = sizeof(hashbuf);
+       CHECK(d0_longhash_bignum(temp2, hashbuf, sz));
+       CHECK(d0_bignum_import_unsigned(temp2, hashbuf, sz));
 
        // hash complete
        CHECK(d0_bignum_mod_mul(temp1, temp2, temp0, ctx->rsa_n));
        CHECK(d0_iobuf_write_bignum(out, temp1));
+       UNLOCKTEMPS();
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(out, outbuflen);
        return 0;
 }
@@ -584,20 +664,23 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_answer_private_id_request(const d0_bli
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *out = NULL;
 
-       // temps: temp0 input, temp1 temp0^d
+       USINGTEMPS(); // temps: temp0 input, temp1 temp0^d
        USING(rsa_d); USING(rsa_n);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
        out = d0_iobuf_open_write(outbuf, *outbuflen);
 
+       LOCKTEMPS();
        CHECK(d0_iobuf_read_bignum(in, temp0));
        CHECK(d0_bignum_mod_pow(temp1, temp0, ctx->rsa_d, ctx->rsa_n));
        CHECK(d0_iobuf_write_bignum(out, temp1));
 
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        d0_iobuf_close(out, outbuflen);
        return 0;
@@ -607,19 +690,23 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_finish_private_id_request(d0_blind_id_
 {
        d0_iobuf_t *in = NULL;
 
-       // temps: temp0 input, temp1 rsa_blind_signature_camouflage^-1
+       USINGTEMPS(); // temps: temp0 input, temp1 rsa_blind_signature_camouflage^-1
        USING(rsa_blind_signature_camouflage); USING(rsa_n);
        REPLACING(schnorr_H_g_to_s_signature);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
 
+       LOCKTEMPS();
+
        CHECK(d0_iobuf_read_bignum(in, temp0));
        CHECK(d0_bignum_mod_inv(temp1, ctx->rsa_blind_signature_camouflage, ctx->rsa_n));
        CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_bignum_mod_mul(ctx->schnorr_H_g_to_s_signature, temp0, temp1, ctx->rsa_n));
 
+       UNLOCKTEMPS();
        return d0_iobuf_close(in, NULL);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        return 0;
 }
@@ -738,12 +825,13 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_
 //   1. get random r, send HASH(4^r)
 {
        d0_iobuf_t *out = NULL;
-       static unsigned char convbuf[1024];
+       unsigned char convbuf[1024];
        d0_iobuf_t *conv = NULL;
        size_t sz = 0;
        D0_BOOL failed = 0;
+       char shabuf[32];
 
-       // temps: temp0 order, temp0 4^r
+       USINGTEMPS(); // temps: temp0 order, temp0 4^r
        if(is_first)
        {
                USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
@@ -764,13 +852,21 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_
 
        // start schnorr ID scheme
        // generate random number r; x = g^r; send hash of x, remember r, forget x
+       LOCKTEMPS();
        CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
+#ifdef RNG_XKCD
+       CHECK_ASSIGN(ctx->r, d0_bignum_int(ctx->r, 4)); // decided by fair dice roll
+#else
        CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0));
-       //CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
+#endif
 
        // initialize Signed Diffie Hellmann
        // we already have the group order in temp1
+#ifdef RNG_XKCD
+       CHECK_ASSIGN(ctx->t, d0_bignum_int(ctx->t, 4)); // decided by fair dice roll
+#else
        CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0));
+#endif
        // can we SOMEHOW do this with just one mod_pow?
 
        CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
@@ -783,15 +879,17 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_
        CHECK(d0_iobuf_write_bignum(conv, ctx->g_to_t));
        CHECK(d0_iobuf_write_packet(conv, msg, msglen));
        CHECK(d0_iobuf_write_bignum(conv, temp0));
+       UNLOCKTEMPS();
        CHECK(d0_iobuf_write_bignum(conv, ctx->g_to_t));
        d0_iobuf_close(conv, &sz);
        conv = NULL;
-       CHECK(d0_iobuf_write_raw(out, sha(convbuf, sz), SCHNORR_HASHSIZE) == SCHNORR_HASHSIZE);
+       CHECK(d0_iobuf_write_raw(out, sha(shabuf, convbuf, sz), SCHNORR_HASHSIZE) == SCHNORR_HASHSIZE);
        CHECK(d0_iobuf_write_packet(out, msg, msglen));
 
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(out, outbuflen);
        return 0;
 }
@@ -804,10 +902,10 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge
 {
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *out = NULL;
-       static unsigned char shabuf[2048];
+       unsigned char hashbuf[2048];
        size_t sz;
 
-       // temps: temp0 order, temp0 signature check
+       USINGTEMPS(); // temps: temp0 order, temp0 signature check
        if(is_first)
        {
                REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature);
@@ -843,15 +941,16 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge
                CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, ctx->rsa_n) < 0);
 
                // check signature of key (t = k^d, so, t^challenge = k)
+               LOCKTEMPS();
                CHECK(d0_bignum_mod_pow(temp0, ctx->schnorr_H_g_to_s_signature, ctx->rsa_e, ctx->rsa_n));
 
                // we will actually sign SHA(4^s) to prevent a malleability attack!
                CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s));
                sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting"
-               if(sz > sizeof(shabuf))
-                       sz = sizeof(shabuf);
-               CHECK(d0_longhash_bignum(temp2, shabuf, sz));
-               CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz));
+               if(sz > sizeof(hashbuf))
+                       sz = sizeof(hashbuf);
+               CHECK(d0_longhash_bignum(temp2, hashbuf, sz));
+               CHECK(d0_bignum_import_unsigned(temp2, hashbuf, sz));
 
                // + 7 / 8 is too large, so let's mod it
                CHECK(d0_bignum_divmod(NULL, temp1, temp2, ctx->rsa_n));
@@ -869,14 +968,24 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge
        CHECK(d0_iobuf_read_packet(in, ctx->msg, &ctx->msglen));
 
        // send challenge
+#ifdef RNG_XKCD
+       CHECK_ASSIGN(ctx->challenge, d0_bignum_int(ctx->challenge, 4)); // decided by fair dice roll
+#else
        CHECK_ASSIGN(ctx->challenge, d0_bignum_rand_bit_atmost(ctx->challenge, SCHNORR_BITS));
+#endif
        CHECK(d0_iobuf_write_bignum(out, ctx->challenge));
 
        // Diffie Hellmann send
+       LOCKTEMPS();
        CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
+#ifdef RNG_XKCD
+       CHECK_ASSIGN(ctx->t, d0_bignum_int(ctx->t, 4)); // decided by fair dice roll
+#else
        CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0));
+#endif
        CHECK(d0_bignum_mod_pow(temp0, four, ctx->t, ctx->schnorr_G));
        CHECK(d0_iobuf_write_bignum(out, temp0));
+       UNLOCKTEMPS();
 
        if(status)
                *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero);
@@ -885,6 +994,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        d0_iobuf_close(out, outbuflen);
        return 0;
@@ -897,13 +1007,14 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response(
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *out = NULL;
 
-       // temps: 0 order, 1 prod, 2 y, 3 challenge
+       USINGTEMPS(); // temps: 0 order, 1 prod, 2 y, 3 challenge
        REPLACING(other_g_to_t); REPLACING(t);
        USING(schnorr_G); USING(schnorr_s); USING(r); USING(g_to_t);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
        out = d0_iobuf_open_write(outbuf, *outbuflen);
 
+       LOCKTEMPS();
        CHECK(d0_iobuf_read_bignum(in, temp3));
        CHECK(d0_bignum_cmp(temp3, zero) >= 0);
        CHECK(d0_bignum_size(temp3) <= SCHNORR_BITS);
@@ -918,6 +1029,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response(
        CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0));
 #endif
        CHECK(d0_iobuf_write_bignum(out, temp2));
+       UNLOCKTEMPS();
 
        // Diffie Hellmann recv
        CHECK_ASSIGN(ctx->other_g_to_t, d0_iobuf_read_bignum(in, ctx->other_g_to_t));
@@ -930,6 +1042,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response(
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        d0_iobuf_close(out, outbuflen);
        return 0;
@@ -941,16 +1054,19 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0
 //      (check using H(g^r) which we know)
 {
        d0_iobuf_t *in = NULL;
-       static unsigned char convbuf[1024];
+       unsigned char convbuf[1024];
        d0_iobuf_t *conv = NULL;
        size_t sz;
+       char shabuf[32];
 
-       // temps: 0 y 1 order
+       USINGTEMPS(); // temps: 0 y 1 order
        USING(challenge); USING(schnorr_G);
        REPLACING(other_g_to_t);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
 
+       LOCKTEMPS();
+
        CHECK(d0_dl_get_order(temp1, ctx->schnorr_G));
        CHECK(d0_iobuf_read_bignum(in, temp0));
        CHECK(d0_bignum_cmp(temp0, zero) >= 0);
@@ -979,10 +1095,11 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0
        CHECK(d0_iobuf_write_bignum(conv, ctx->other_g_to_t));
        CHECK(d0_iobuf_write_packet(conv, ctx->msg, ctx->msglen));
        CHECK(d0_iobuf_write_bignum(conv, temp3));
+       UNLOCKTEMPS();
        CHECK(d0_iobuf_write_bignum(conv, ctx->other_g_to_t));
        d0_iobuf_close(conv, &sz);
        conv = NULL;
-       if(memcmp(sha(convbuf, sz), ctx->msghash, SCHNORR_HASHSIZE))
+       if(memcmp(sha(shabuf, convbuf, sz), ctx->msghash, SCHNORR_HASHSIZE))
        {
                // FAIL (not owned by player)
                goto fail;
@@ -1001,6 +1118,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0
        return 1;
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        return 0;
 }
@@ -1008,36 +1126,43 @@ fail:
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_generate_missing_signature(d0_blind_id_t *ctx)
 {
        size_t sz;
-       static unsigned char shabuf[2048];
+       unsigned char hashbuf[2048];
 
+       USINGTEMPS(); // temps: 2 hash
        REPLACING(schnorr_H_g_to_s_signature);
        USING(schnorr_g_to_s); USING(rsa_d); USING(rsa_n);
 
+       LOCKTEMPS();
+
        // we will actually sign SHA(4^s) to prevent a malleability attack!
-       CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s));
        sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting"
-       if(sz > sizeof(shabuf))
-               sz = sizeof(shabuf);
-       CHECK(d0_longhash_bignum(temp2, shabuf, sz));
-       CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz));
+       if(sz > sizeof(hashbuf))
+               sz = sizeof(hashbuf);
+       CHECK(d0_longhash_bignum(ctx->schnorr_g_to_s, hashbuf, sz));
+       LOCKTEMPS();
+       CHECK(d0_bignum_import_unsigned(temp2, hashbuf, sz));
 
        // + 7 / 8 is too large, so let's mod it
        CHECK(d0_bignum_divmod(NULL, temp1, temp2, ctx->rsa_n));
        CHECK(d0_bignum_mod_pow(ctx->schnorr_H_g_to_s_signature, temp1, ctx->rsa_d, ctx->rsa_n));
+
+       UNLOCKTEMPS();
        return 1;
 
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
-D0_WARN_UNUSED_RESULT D0_BOOL d0_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)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign_internal(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, D0_BOOL with_msg, const char *message, size_t msglen, char *outbuf, size_t *outbuflen)
 {
        d0_iobuf_t *out = NULL;
-       static unsigned char convbuf[1024];
-       static unsigned char shabuf[1024];
+       unsigned char *convbuf = NULL;
+       unsigned char hashbuf[2048];
        d0_iobuf_t *conv = NULL;
        size_t sz = 0;
 
+       USINGTEMPS(); // temps: 0 order 1 4^r 2 hash
        if(is_first)
        {
                USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
@@ -1059,18 +1184,21 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign(d0_blind_id_
 
        // start schnorr SIGNATURE scheme
        // generate random number r; x = g^r; send hash of H(m||r), remember r, forget x
+       LOCKTEMPS();
        CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
        CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0));
        CHECK(d0_bignum_mod_pow(temp1, four, ctx->r, ctx->schnorr_G));
 
        // hash it, hash it, everybody hash it
-       conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
+       conv = d0_iobuf_open_write_p((void **) &convbuf, 0);
        CHECK(d0_iobuf_write_packet(conv, message, msglen));
        CHECK(d0_iobuf_write_bignum(conv, temp1));
        d0_iobuf_close(conv, &sz);
        conv = NULL;
-       CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp0) + 7) / 8));
-       CHECK(d0_bignum_import_unsigned(temp2, shabuf, (d0_bignum_size(temp0) + 7) / 8));
+       CHECK(d0_longhash_destructive(convbuf, sz, hashbuf, (d0_bignum_size(temp0) + 7) / 8));
+       d0_free(convbuf);
+       convbuf = NULL;
+       CHECK(d0_bignum_import_unsigned(temp2, hashbuf, (d0_bignum_size(temp0) + 7) / 8));
        CHECK(d0_iobuf_write_bignum(out, temp2));
 
        // multiply with secret, sub k, modulo order
@@ -1081,25 +1209,37 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign(d0_blind_id_
        CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0));
 #endif
        CHECK(d0_iobuf_write_bignum(out, temp2));
+       UNLOCKTEMPS();
 
        // write the message itself
-       CHECK(d0_iobuf_write_packet(out, message, msglen));
+       if(with_msg)
+               CHECK(d0_iobuf_write_packet(out, message, msglen));
 
        return d0_iobuf_close(out, outbuflen);
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(out, outbuflen);
        return 0;
 }
+D0_WARN_UNUSED_RESULT D0_BOOL d0_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)
+{
+       return d0_blind_id_sign_with_private_id_sign_internal(ctx, is_first, send_modulus, 1, message, msglen, outbuf, outbuflen);
+}
+D0_WARN_UNUSED_RESULT D0_BOOL d0_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)
+{
+       return d0_blind_id_sign_with_private_id_sign_internal(ctx, is_first, send_modulus, 0, message, msglen, outbuf, outbuflen);
+}
 
-D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_internal(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, D0_BOOL with_msg, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status)
 {
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *conv = NULL;
-       static unsigned char convbuf[2048];
-       static unsigned char shabuf[2048];
+       unsigned char *convbuf = NULL;
+       unsigned char hashbuf[2048];
        size_t sz;
 
+       USINGTEMPS(); // temps: 0 sig^e 2 g^s 3 g^-s 4 order
        if(is_first)
        {
                REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature);
@@ -1133,15 +1273,15 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i
                CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, ctx->rsa_n) < 0);
 
                // check signature of key (t = k^d, so, t^challenge = k)
+               LOCKTEMPS();
                CHECK(d0_bignum_mod_pow(temp0, ctx->schnorr_H_g_to_s_signature, ctx->rsa_e, ctx->rsa_n));
 
                // we will actually sign SHA(4^s) to prevent a malleability attack!
-               CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s));
                sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting"
-               if(sz > sizeof(shabuf))
-                       sz = sizeof(shabuf);
-               CHECK(d0_longhash_bignum(temp2, shabuf, sz));
-               CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz));
+               if(sz > sizeof(hashbuf))
+                       sz = sizeof(hashbuf);
+               CHECK(d0_longhash_bignum(ctx->schnorr_g_to_s, hashbuf, sz));
+               CHECK(d0_bignum_import_unsigned(temp2, hashbuf, sz));
 
                // + 7 / 8 is too large, so let's mod it
                CHECK(d0_bignum_divmod(NULL, temp1, temp2, ctx->rsa_n));
@@ -1157,7 +1297,8 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i
        CHECK(d0_dl_get_order(temp4, ctx->schnorr_G));
        CHECK(d0_iobuf_read_bignum(in, temp0)); // e == H(m || g^r)
        CHECK(d0_iobuf_read_bignum(in, temp1)); // x == (r - s*e) mod |G|
-       CHECK(d0_iobuf_read_packet(in, msg, msglen));
+       if(with_msg)
+               CHECK(d0_iobuf_read_packet(in, msg, msglen));
 
        // VERIFY: g^x * (g^s)^-e = g^(x - s*e) = g^r
 
@@ -1173,16 +1314,19 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i
        CHECK_ASSIGN(temp3, d0_bignum_mod_mul(temp3, temp1, temp2, ctx->schnorr_G)); // temp3 now is g^r
 
        // hash it, hash it, everybody hash it
-       conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
+       conv = d0_iobuf_open_write_p((void **) &convbuf, 0);
        CHECK(d0_iobuf_write_packet(conv, msg, *msglen));
        CHECK(d0_iobuf_write_bignum(conv, temp3));
        d0_iobuf_close(conv, &sz);
        conv = NULL;
-       CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp4) + 7) / 8));
-       CHECK(d0_bignum_import_unsigned(temp1, shabuf, (d0_bignum_size(temp4) + 7) / 8));
+       CHECK(d0_longhash_destructive(convbuf, sz, hashbuf, (d0_bignum_size(temp4) + 7) / 8));
+       d0_free(convbuf);
+       convbuf = NULL;
+       CHECK(d0_bignum_import_unsigned(temp1, hashbuf, (d0_bignum_size(temp4) + 7) / 8));
 
        // verify signature
        CHECK(!d0_bignum_cmp(temp0, temp1));
+       UNLOCKTEMPS();
 
        if(status)
                *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero);
@@ -1191,16 +1335,26 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i
        return 1;
 
 fail:
+       UNLOCKTEMPS();
        d0_iobuf_close(in, NULL);
        return 0;
 }
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status)
+{
+       return d0_blind_id_sign_with_private_id_verify_internal(ctx, is_first, recv_modulus, 1, inbuf, inbuflen, msg, msglen, status);
+}
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_detached(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, const char *msg, size_t msglen, D0_BOOL *status)
+{
+       return d0_blind_id_sign_with_private_id_verify_internal(ctx, is_first, recv_modulus, 0, inbuf, inbuflen, (char *) msg, &msglen, status);
+}
 
 D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
        d0_iobuf_t *out = NULL;
-       static unsigned char convbuf[1024];
+       unsigned char convbuf[1024];
        d0_iobuf_t *conv = NULL;
        size_t sz, n;
+       char shabuf[32];
 
        USING(rsa_n);
        USING(rsa_e);
@@ -1218,7 +1372,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_id(const d0_blind
        n = (*outbuflen / 4) * 3;
        if(n > SHA_DIGESTSIZE)
                n = SHA_DIGESTSIZE;
-       CHECK(d0_iobuf_write_raw(out, sha(convbuf, sz), n) == n);
+       CHECK(d0_iobuf_write_raw(out, sha(shabuf, convbuf, sz), n) == n);
        CHECK(d0_iobuf_conv_base64_out(out));
 
        return d0_iobuf_close(out, outbuflen);
@@ -1232,13 +1386,19 @@ fail:
 
 D0_BOOL d0_blind_id_sessionkey_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
+       D0_BOOL ret;
+
+       USINGTEMPS(); // temps: temp0 result
        USING(t); USING(other_g_to_t); USING(schnorr_G);
 
-       // temps: temp0 result
+       LOCKTEMPS();
        CHECK(d0_bignum_mod_pow(temp0, ctx->other_g_to_t, ctx->t, ctx->schnorr_G));
-       return d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen);
+       ret = d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen);
+       UNLOCKTEMPS();
+       return ret;
 
 fail:
+       UNLOCKTEMPS();
        return 0;
 }
 
@@ -1262,3 +1422,12 @@ void d0_blind_id_util_sha256(char *out, const char *in, size_t n)
        SHA256_Update(&context, (const unsigned char *) in, n);
        return SHA256_Final((unsigned char *) out, &context);
 }
+
+void d0_blind_id_setmallocfuncs(d0_malloc_t *m, d0_free_t *f)
+{
+       d0_setmallocfuncs(m, f);
+}
+void d0_blind_id_setmutexfuncs(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u)
+{
+       d0_setmutexfuncs(c, d, l, u);
+}