/*
-Blind-ID library for user identification using RSA blind signatures
-Copyright (C) 2010 Rudolf Polzer
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Lesser General Public
-License as published by the Free Software Foundation; either
-version 2.1 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Lesser General Public License for more details.
-
-You should have received a copy of the GNU Lesser General Public
-License along with this library; if not, write to the Free Software
-Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-*/
+ * FILE: d0_blind_id.c
+ * AUTHOR: Rudolf Polzer - divVerent@xonotic.org
+ *
+ * Copyright (c) 2010, Rudolf Polzer
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Format:commit %H$
+ * $Id$
+ */
#include "d0_blind_id.h"
#include <stdio.h>
#include <string.h>
#include "d0_bignum.h"
-#include "sha1.h"
+#include "sha2.h"
+
+// old "positive" protocol, uses one extra mod_inv in verify stages
+// #define D0_BLIND_ID_POSITIVE_PROTOCOL
+
+// our SHA is SHA-256
+#define SHA_DIGESTSIZE 32
+const unsigned char *sha(unsigned char *h, const unsigned char *in, size_t len)
+{
+ d0_blind_id_util_sha256((char *) h, (const char *) in, len);
+ return h;
+}
// for zero knowledge, we need multiple instances of schnorr ID scheme... should normally be sequential
// parallel schnorr ID is not provably zero knowledge :(
#define SCHNORR_BITS 20
// probability of cheat: 2^(-bits+1)
-#define SCHNORR_HASHSIZE 3
-// cannot be >= SHA_DIGEST_LENGTH
+#define SCHNORR_HASHSIZE SHA_DIGESTSIZE
+// cannot be >= SHA_DIGESTSIZE
// *8 must be >= SCHNORR_BITS
+// no need to save bits here
#define MSGSIZE 640 // ought to be enough for anyone
d0_bignum_t *schnorr_s;
// public data (player ID public key, this is what the server gets to know)
- d0_bignum_t *schnorr_4_to_s;
- d0_bignum_t *schnorr_4_to_s_signature; // 0 when signature is invalid
+ d0_bignum_t *schnorr_g_to_s;
+ d0_bignum_t *schnorr_H_g_to_s_signature; // 0 when signature is invalid
+ // as hash function H, we get the SHA1 and reinterpret as bignum - yes, it always is < 160 bits
// temp data
d0_bignum_t *rsa_blind_signature_camouflage; // random number blind signature
d0_bignum_t *r; // random number for schnorr ID
- d0_bignum_t *other_4_to_r; // for DH key exchange
+ d0_bignum_t *t; // for DH key exchange
+ d0_bignum_t *g_to_t; // for DH key exchange
+ d0_bignum_t *other_g_to_t; // for DH key exchange
d0_bignum_t *challenge; // challenge
char msghash[SCHNORR_HASHSIZE]; // init hash
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)
+#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);
-void d0_blind_id_INITIALIZE(void)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void)
{
- d0_bignum_INITIALIZE();
+ 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));
CHECK_ASSIGN(four, d0_bignum_int(four, 4));
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);
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
return NULL;
}
-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;
continue;
if(d0_bignum_isprime(temp0, 10) == 0) // finish the previous test
continue;
+ UNLOCKTEMPS();
break;
}
return 1;
fail:
+ UNLOCKTEMPS();
return 0;
}
-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;
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)
+ if(++gcdfail == 16)
+ goto fail;
+ }
+ UNLOCKTEMPS();
+
+ gcdfail = 0;
+ for (;;)
+ {
+ LOCKTEMPS();
+ CHECK(d0_bignum_rand_bit_exact(temp1, qb));
+ if(!d0_bignum_cmp(temp1, ctx->rsa_d))
+ {
+ UNLOCKTEMPS();
+ if(++fail == 16)
+ 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, ctx->rsa_e));
+ if(!d0_bignum_cmp(temp4, one))
+ {
+ // we do NOT unlock, as we still need temp1 and temp3
+ break;
+ }
+ UNLOCKTEMPS();
+ if(++gcdfail == 16)
+ goto fail;
+ }
+
+ // ctx->rsa_n = ctx->rsa_d*temp1
+ CHECK(d0_bignum_mul(ctx->rsa_n, ctx->rsa_d, temp1));
+
+ // 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(temp1, temp2, temp3));
+ CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp1));
+ UNLOCKTEMPS();
+ return 1;
+fail:
+ UNLOCKTEMPS();
+ return 0;
+}
+
+// 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)
+{
+ USINGTEMPS(); // uses temp1 to temp4
+ int fail = 0;
+ int gcdfail = 0;
+ int pb = (size + 1)/2;
+ int qb = size - pb;
+ if(pb < 8)
+ pb = 8;
+ if(qb < 8)
+ qb = 8;
+
+ // we use ctx->rsa_d for the first result so that we can unlock temps later
+ for (;;)
+ {
+ 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, ctx->rsa_d, one));
+ CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, ctx->rsa_e));
+ if(!d0_bignum_cmp(temp4, one))
+ break;
+ if(++gcdfail == 16)
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))
{
- if(++fail == 3)
+ UNLOCKTEMPS();
+ if(++fail == 16)
return 0;
+ continue;
}
fail = 0;
+
+ // 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, 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 temp3
break;
- if(++gcdfail == 3)
+ }
+ UNLOCKTEMPS();
+ if(++gcdfail == 16)
return 0;
- ++gcdfail;
}
- // n = temp0*temp1
- CHECK(d0_bignum_mul(n, temp0, temp1));
-
- // d = challenge^-1 mod (temp0-1)(temp1-1)
- CHECK(d0_bignum_mul(temp0, temp2, temp3));
- CHECK(d0_bignum_mod_inv(d, challenge, temp0));
+ // 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(temp1, temp2, temp3));
+ CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp1));
+ 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(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(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)
+{
+ unsigned char convbuf[1024];
+ size_t sz;
+
+ CHECK(d0_bignum_export_unsigned(in, convbuf, sizeof(convbuf)) >= 0);
+ sz = (d0_bignum_size(in) + 7) / 8;
+ CHECK(d0_longhash_destructive(convbuf, sz, outbuf, outbuflen));
return 1;
+
fail:
return 0;
}
if(ctx->rsa_d) d0_bignum_free(ctx->rsa_d);
if(ctx->schnorr_G) d0_bignum_free(ctx->schnorr_G);
if(ctx->schnorr_s) d0_bignum_free(ctx->schnorr_s);
- if(ctx->schnorr_4_to_s) d0_bignum_free(ctx->schnorr_4_to_s);
- if(ctx->schnorr_4_to_s_signature) d0_bignum_free(ctx->schnorr_4_to_s_signature);
+ if(ctx->schnorr_g_to_s) d0_bignum_free(ctx->schnorr_g_to_s);
+ if(ctx->schnorr_H_g_to_s_signature) d0_bignum_free(ctx->schnorr_H_g_to_s_signature);
if(ctx->rsa_blind_signature_camouflage) d0_bignum_free(ctx->rsa_blind_signature_camouflage);
if(ctx->r) d0_bignum_free(ctx->r);
if(ctx->challenge) d0_bignum_free(ctx->challenge);
- if(ctx->other_4_to_r) d0_bignum_free(ctx->other_4_to_r);
+ if(ctx->t) d0_bignum_free(ctx->t);
+ if(ctx->g_to_t) d0_bignum_free(ctx->g_to_t);
+ if(ctx->other_g_to_t) d0_bignum_free(ctx->other_g_to_t);
memset(ctx, 0, sizeof(*ctx));
}
-void d0_blind_id_copy(d0_blind_id_t *ctx, const d0_blind_id_t *src)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_copy(d0_blind_id_t *ctx, const d0_blind_id_t *src)
{
d0_blind_id_clear(ctx);
- if(src->rsa_n) ctx->rsa_n = d0_bignum_mov(NULL, src->rsa_n);
- if(src->rsa_e) ctx->rsa_e = d0_bignum_mov(NULL, src->rsa_e);
- if(src->rsa_d) ctx->rsa_d = d0_bignum_mov(NULL, src->rsa_d);
- if(src->schnorr_G) ctx->schnorr_G = d0_bignum_mov(NULL, src->schnorr_G);
- if(src->schnorr_s) ctx->schnorr_s = d0_bignum_mov(NULL, src->schnorr_s);
- if(src->schnorr_4_to_s) ctx->schnorr_4_to_s = d0_bignum_mov(NULL, ctx->schnorr_G);
- if(src->schnorr_4_to_s_signature) ctx->schnorr_4_to_s_signature = d0_bignum_mov(NULL, src->schnorr_4_to_s_signature);
- if(src->rsa_blind_signature_camouflage) ctx->rsa_blind_signature_camouflage = d0_bignum_mov(NULL, src->rsa_blind_signature_camouflage);
- if(src->r) ctx->r = d0_bignum_mov(NULL, src->r);
- if(src->challenge) ctx->challenge = d0_bignum_mov(NULL, src->challenge);
- if(src->other_4_to_r) ctx->other_4_to_r = d0_bignum_mov(NULL, src->other_4_to_r);
+ if(src->rsa_n) CHECK_ASSIGN(ctx->rsa_n, d0_bignum_mov(NULL, src->rsa_n));
+ if(src->rsa_e) CHECK_ASSIGN(ctx->rsa_e, d0_bignum_mov(NULL, src->rsa_e));
+ if(src->rsa_d) CHECK_ASSIGN(ctx->rsa_d, d0_bignum_mov(NULL, src->rsa_d));
+ if(src->schnorr_G) CHECK_ASSIGN(ctx->schnorr_G, d0_bignum_mov(NULL, src->schnorr_G));
+ if(src->schnorr_s) CHECK_ASSIGN(ctx->schnorr_s, d0_bignum_mov(NULL, src->schnorr_s));
+ if(src->schnorr_g_to_s) CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_bignum_mov(NULL, src->schnorr_g_to_s));
+ if(src->schnorr_H_g_to_s_signature) CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_bignum_mov(NULL, src->schnorr_H_g_to_s_signature));
+ if(src->rsa_blind_signature_camouflage) CHECK_ASSIGN(ctx->rsa_blind_signature_camouflage, d0_bignum_mov(NULL, src->rsa_blind_signature_camouflage));
+ if(src->r) CHECK_ASSIGN(ctx->r, d0_bignum_mov(NULL, src->r));
+ if(src->challenge) CHECK_ASSIGN(ctx->challenge, d0_bignum_mov(NULL, src->challenge));
+ if(src->t) CHECK_ASSIGN(ctx->t, d0_bignum_mov(NULL, src->t));
+ if(src->g_to_t) CHECK_ASSIGN(ctx->g_to_t, d0_bignum_mov(NULL, src->g_to_t));
+ if(src->other_g_to_t) CHECK_ASSIGN(ctx->other_g_to_t, d0_bignum_mov(NULL, src->other_g_to_t));
memcpy(ctx->msg, src->msg, sizeof(ctx->msg));
ctx->msglen = src->msglen;
memcpy(ctx->msghash, src->msghash, sizeof(ctx->msghash));
+ return 1;
+fail:
+ d0_blind_id_clear(ctx);
+ return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_key(d0_blind_id_t *ctx, int k)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key_fastreject(d0_blind_id_t *ctx, int k, d0_fastreject_function reject, void *pass)
{
REPLACING(rsa_e); REPLACING(rsa_d); REPLACING(rsa_n);
CHECK_ASSIGN(ctx->rsa_e, d0_bignum_int(ctx->rsa_e, 65537));
CHECK_ASSIGN(ctx->rsa_d, d0_bignum_zero(ctx->rsa_d));
CHECK_ASSIGN(ctx->rsa_n, d0_bignum_zero(ctx->rsa_n));
- CHECK(d0_rsa_generate_key(k+1, ctx->rsa_e, ctx->rsa_d, ctx->rsa_n)); // must fit G for sure
+ 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)); // must fit G for sure
return 1;
fail:
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key(d0_blind_id_t *ctx, int k)
+{
+ return d0_blind_id_generate_private_key_fastreject(ctx, k, NULL, NULL);
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
d0_iobuf_t *in = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_read_public_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_public_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
d0_iobuf_t *in = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_key(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
{
d0_iobuf_t *out = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_write_public_key(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
{
d0_iobuf_t *out = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_modulus(d0_blind_id_t *ctx)
+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;
+ unsigned char convbuf[2048];
+ d0_iobuf_t *conv = NULL;
+ size_t sz, n;
+ char shabuf[32];
+
+ USING(rsa_n); USING(rsa_e);
+
+ out = d0_iobuf_open_write(outbuf, *outbuflen);
+ conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
+
+ CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_n));
+ CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_e));
+ CHECK(d0_iobuf_close(conv, &sz));
+ conv = NULL;
+
+ n = (*outbuflen / 4) * 3;
+ if(n > SHA_DIGESTSIZE)
+ n = SHA_DIGESTSIZE;
+ 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);
+
+fail:
+ if(conv)
+ d0_iobuf_close(conv, &sz);
+ d0_iobuf_close(out, outbuflen);
+ return 0;
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_modulus(d0_blind_id_t *ctx)
{
USING(rsa_n);
REPLACING(schnorr_G);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id_modulus(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id_modulus(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
d0_iobuf_t *in = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id_modulus(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id_modulus(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
{
d0_iobuf_t *out = NULL;
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx)
+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_4_to_s);
+ 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_4_to_s, d0_bignum_mod_pow(ctx->schnorr_4_to_s, four, ctx->schnorr_s, ctx->schnorr_G));
- CHECK_ASSIGN(ctx->schnorr_4_to_s_signature, d0_bignum_zero(ctx->schnorr_4_to_s_signature));
+ 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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+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;
+ unsigned char hashbuf[2048];
+ size_t sz;
- // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge
- USING(rsa_n); USING(rsa_e); USING(schnorr_4_to_s);
+ 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);
out = d0_iobuf_open_write(outbuf, *outbuflen);
CHECK_ASSIGN(ctx->rsa_blind_signature_camouflage, d0_bignum_rand_bit_atmost(ctx->rsa_blind_signature_camouflage, d0_bignum_size(ctx->rsa_n)));
CHECK(d0_bignum_mod_pow(temp0, ctx->rsa_blind_signature_camouflage, ctx->rsa_e, ctx->rsa_n));
- CHECK(d0_bignum_mod_mul(temp1, ctx->schnorr_4_to_s, temp0, ctx->rsa_n));
+
+ // we will actually sign HA(4^s) to prevent a malleability attack!
+ LOCKTEMPS();
+ 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(hashbuf))
+ sz = sizeof(hashbuf);
+ CHECK(d0_longhash_bignum(ctx->schnorr_g_to_s, 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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_answer_private_id_request(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_answer_private_id_request(const d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
{
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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_finish_private_id_request(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_finish_private_id_request(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
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_4_to_s_signature);
+ 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_4_to_s_signature, d0_bignum_mod_mul(ctx->schnorr_4_to_s_signature, temp0, temp1, 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;
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id_request_camouflage(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+{
+ d0_iobuf_t *in = NULL;
+
+ REPLACING(rsa_blind_signature_camouflage);
+
+ in = d0_iobuf_open_read(inbuf, inbuflen);
+
+ CHECK_ASSIGN(ctx->rsa_blind_signature_camouflage, d0_iobuf_read_bignum(in, ctx->rsa_blind_signature_camouflage));
return d0_iobuf_close(in, NULL);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id_request_camouflage(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+{
+ d0_iobuf_t *out = NULL;
+
+ USING(rsa_blind_signature_camouflage);
+
+ out = d0_iobuf_open_write(outbuf, *outbuflen);
+
+ CHECK(d0_iobuf_write_bignum(out, ctx->rsa_blind_signature_camouflage));
+
+ return d0_iobuf_close(out, outbuflen);
+
+fail:
+ d0_iobuf_close(out, outbuflen);
+ return 0;
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
d0_iobuf_t *in = NULL;
- REPLACING(schnorr_s); REPLACING(schnorr_4_to_s); REPLACING(schnorr_4_to_s_signature);
+ REPLACING(schnorr_s); REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature);
in = d0_iobuf_open_read(inbuf, inbuflen);
CHECK_ASSIGN(ctx->schnorr_s, d0_iobuf_read_bignum(in, ctx->schnorr_s));
- CHECK_ASSIGN(ctx->schnorr_4_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s));
- CHECK_ASSIGN(ctx->schnorr_4_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s_signature));
+ CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_g_to_s));
+ CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_H_g_to_s_signature));
return d0_iobuf_close(in, NULL);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_read_public_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_public_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
{
d0_iobuf_t *in = NULL;
- REPLACING(schnorr_4_to_s); REPLACING(schnorr_4_to_s_signature);
+ REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature);
in = d0_iobuf_open_read(inbuf, inbuflen);
- CHECK_ASSIGN(ctx->schnorr_4_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s));
- CHECK_ASSIGN(ctx->schnorr_4_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s_signature));
+ CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_g_to_s));
+ CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_H_g_to_s_signature));
return d0_iobuf_close(in, NULL);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
{
d0_iobuf_t *out = NULL;
- USING(schnorr_s); USING(schnorr_4_to_s); USING(schnorr_4_to_s_signature);
+ USING(schnorr_s); USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
out = d0_iobuf_open_write(outbuf, *outbuflen);
CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_s));
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s));
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s_signature));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_g_to_s));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_H_g_to_s_signature));
return d0_iobuf_close(out, outbuflen);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_write_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
{
d0_iobuf_t *out = NULL;
- USING(schnorr_4_to_s); USING(schnorr_4_to_s_signature);
+ USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
out = d0_iobuf_open_write(outbuf, *outbuflen);
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s));
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s_signature));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_g_to_s));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_H_g_to_s_signature));
return d0_iobuf_close(out, outbuflen);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_id_t *ctx, BOOL is_first, BOOL send_modulus, char *msg, size_t msglen, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *msg, size_t msglen, char *outbuf, size_t *outbuflen)
// start =
// first run: send 4^s, 4^s signature
// 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_4_to_s); USING(schnorr_4_to_s_signature);
+ USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
}
USING(schnorr_G);
- REPLACING(r);
+ REPLACING(r); REPLACING(t); REPLACING(g_to_t);
out = d0_iobuf_open_write(outbuf, *outbuflen);
// send ID
if(send_modulus)
CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_G));
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s));
- CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_4_to_s_signature));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_g_to_s));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_H_g_to_s_signature));
}
// 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));
+#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));
+ CHECK_ASSIGN(ctx->g_to_t, d0_bignum_mod_pow(ctx->g_to_t, four, ctx->t, ctx->schnorr_G));
+ CHECK(!failed);
// hash it, hash it, everybody hash it
conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
CHECK(d0_iobuf_write_bignum(conv, temp0));
+ 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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_blind_id_t *ctx, BOOL is_first, BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen, BOOL *status)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_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)
// first run: get 4^s, 4^s signature
// 1. check sig
// 2. save HASH(4^r)
{
d0_iobuf_t *in = NULL;
d0_iobuf_t *out = NULL;
+ 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_4_to_s); REPLACING(schnorr_4_to_s_signature);
+ REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature);
if(recv_modulus)
REPLACING(schnorr_G);
else
}
else
{
- USING(schnorr_4_to_s); USING(schnorr_4_to_s_signature);
+ USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
USING(schnorr_G);
}
USING(rsa_e); USING(rsa_n);
- REPLACING(challenge); REPLACING(msg); REPLACING(msglen); REPLACING(msghash); REPLACING(r);
+ REPLACING(challenge); REPLACING(msg); REPLACING(msglen); REPLACING(msghash); REPLACING(r); REPLACING(t);
in = d0_iobuf_open_read(inbuf, inbuflen);
out = d0_iobuf_open_write(outbuf, *outbuflen);
CHECK(d0_bignum_cmp(ctx->schnorr_G, zero) > 0);
CHECK(d0_bignum_cmp(ctx->schnorr_G, ctx->rsa_n) < 0);
}
- CHECK_ASSIGN(ctx->schnorr_4_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s));
- CHECK(d0_bignum_cmp(ctx->schnorr_4_to_s, zero) > 0);
- CHECK(d0_bignum_cmp(ctx->schnorr_4_to_s, ctx->schnorr_G) < 0);
- CHECK_ASSIGN(ctx->schnorr_4_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_4_to_s_signature));
- CHECK(d0_bignum_cmp(ctx->schnorr_4_to_s_signature, zero) >= 0);
- CHECK(d0_bignum_cmp(ctx->schnorr_4_to_s_signature, ctx->rsa_n) < 0);
-
- // check signature of key (t = k^d, so, t^challenge = k)
- CHECK(d0_bignum_mod_pow(temp0, ctx->schnorr_4_to_s_signature, ctx->rsa_e, ctx->rsa_n));
- if(d0_bignum_cmp(temp0, ctx->schnorr_4_to_s))
+ CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_g_to_s));
+ CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, zero) >= 0);
+ CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, ctx->schnorr_G) < 0);
+ CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_H_g_to_s_signature));
+ CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero) >= 0);
+ CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, ctx->rsa_n) < 0);
+
+ if(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero))
{
- // accept the key anyway, but mark as failed signature! will later return 0 in status
- CHECK(d0_bignum_zero(ctx->schnorr_4_to_s_signature));
+ // 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!
+ 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(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));
+
+ // hash complete
+ CHECK(d0_bignum_cmp(temp0, temp1) == 0);
}
}
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
+ // Diffie Hellmann send
+ 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(temp0, four, ctx->r, 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_4_to_s_signature, zero);
+ *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero);
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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
// 1. read challenge challenge of SCHNORR_BITS
// 2. reply with r + s * challenge mod order
{
d0_iobuf_t *in = NULL;
d0_iobuf_t *out = NULL;
- // temps: 0 order, 1 prod, 2 y, 3 challenge
- REPLACING(other_4_to_r);
- USING(schnorr_G); USING(schnorr_s); USING(r);
+ 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);
- // Diffie Hellmann
- CHECK_ASSIGN(ctx->other_4_to_r, d0_iobuf_read_bignum(in, ctx->other_4_to_r));
- CHECK(d0_bignum_cmp(ctx->other_4_to_r, zero) > 0);
- CHECK(d0_bignum_cmp(ctx->other_4_to_r, ctx->schnorr_G) < 0);
-
// send response for schnorr ID scheme
// i.challenge. r + ctx->schnorr_s * temp3
CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
CHECK(d0_bignum_mod_mul(temp1, ctx->schnorr_s, temp3, temp0));
- CHECK(d0_bignum_mod_add(temp2, temp1, ctx->r, temp0));
+#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL
+ CHECK(d0_bignum_mod_add(temp2, ctx->r, temp1, temp0));
+#else
+ 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));
+ CHECK(d0_bignum_cmp(ctx->other_g_to_t, zero) > 0);
+ CHECK(d0_bignum_cmp(ctx->other_g_to_t, ctx->schnorr_G) < 0);
+ // Diffie Hellmann send
+ CHECK(d0_iobuf_write_bignum(out, ctx->g_to_t));
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;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_verify(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, BOOL *status)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_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)
// 1. read y = r + s * challenge mod order
// 2. verify: g^y (g^s)^-challenge = g^(r+s*challenge-s*challenge) = g^r
// (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_4_to_r);
+ 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);
CHECK(d0_bignum_cmp(temp0, temp1) < 0);
// verify schnorr ID scheme
- // we need 4^temp0 (g^s)^-challenge
- CHECK(d0_bignum_neg(temp1, ctx->challenge));
- CHECK(d0_bignum_mod_pow(temp2, ctx->schnorr_4_to_s, temp1, ctx->schnorr_G));
+#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL
+ // we need 4^r = 4^temp0 (g^s)^-challenge
+ CHECK(d0_bignum_mod_inv(temp1, ctx->schnorr_g_to_s, ctx->schnorr_G));
+ CHECK(d0_bignum_mod_pow(temp2, temp1, ctx->challenge, ctx->schnorr_G));
+#else
+ // we need 4^r = 4^temp0 (g^s)^challenge
+ CHECK(d0_bignum_mod_pow(temp2, ctx->schnorr_g_to_s, ctx->challenge, ctx->schnorr_G));
+#endif
CHECK(d0_bignum_mod_pow(temp1, four, temp0, ctx->schnorr_G));
- CHECK_ASSIGN(ctx->other_4_to_r, d0_bignum_mod_mul(ctx->other_4_to_r, temp1, temp2, ctx->schnorr_G));
- // hash must be equal to msghash
+ CHECK_ASSIGN(temp3, d0_bignum_mod_mul(temp3, temp1, temp2, ctx->schnorr_G));
+
+ // Diffie Hellmann recv
+ CHECK_ASSIGN(ctx->other_g_to_t, d0_iobuf_read_bignum(in, ctx->other_g_to_t));
+ CHECK(d0_bignum_cmp(ctx->other_g_to_t, zero) > 0);
+ CHECK(d0_bignum_cmp(ctx->other_g_to_t, ctx->schnorr_G) < 0);
// hash it, hash it, everybody hash it
conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
- CHECK(d0_iobuf_write_bignum(conv, ctx->other_4_to_r));
+ CHECK(d0_iobuf_write_bignum(conv, temp3));
+ 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, ctx->other_4_to_r));
+ 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;
}
if(status)
- *status = !!d0_bignum_cmp(ctx->schnorr_4_to_s_signature, zero);
+ *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero);
if(ctx->msglen <= *msglen)
memcpy(msg, ctx->msg, ctx->msglen);
return 1;
fail:
+ UNLOCKTEMPS();
d0_iobuf_close(in, NULL);
return 0;
}
-WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_generate_missing_signature(d0_blind_id_t *ctx)
+{
+ size_t sz;
+ 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!
+ 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(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_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];
+ unsigned char *convbuf = NULL;
+ unsigned char hashbuf[2048];
d0_iobuf_t *conv = NULL;
- size_t sz, n;
+ size_t sz = 0;
- USING(schnorr_4_to_s);
+ USINGTEMPS(); // temps: 0 order 1 4^r 2 hash
+ if(is_first)
+ {
+ USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
+ }
+ USING(schnorr_G);
+ USING(schnorr_s);
+ REPLACING(r);
out = d0_iobuf_open_write(outbuf, *outbuflen);
- conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
- CHECK(d0_iobuf_write_bignum(conv, ctx->schnorr_4_to_s));
- CHECK(d0_iobuf_close(conv, &sz));
+ if(is_first)
+ {
+ // send ID
+ if(send_modulus)
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_G));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_g_to_s));
+ CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_H_g_to_s_signature));
+ }
+
+ // 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_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, 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));
- 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_conv_base64_out(out));
+ // multiply with secret, sub k, modulo order
+ CHECK(d0_bignum_mod_mul(temp1, temp2, ctx->schnorr_s, temp0));
+#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL
+ CHECK(d0_bignum_mod_add(temp2, ctx->r, temp1, temp0));
+#else
+ CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0));
+#endif
+ CHECK(d0_iobuf_write_bignum(out, temp2));
+ UNLOCKTEMPS();
+
+ // write the message itself
+ if(with_msg)
+ CHECK(d0_iobuf_write_packet(out, message, msglen));
return d0_iobuf_close(out, outbuflen);
fail:
- if(conv)
- d0_iobuf_close(conv, &sz);
+ 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);
+}
-BOOL d0_blind_id_sessionkey_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
+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;
+ 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);
+ if(recv_modulus)
+ REPLACING(schnorr_G);
+ else
+ USING(schnorr_G);
+ }
+ else
+ {
+ USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature);
+ USING(schnorr_G);
+ }
+ USING(rsa_e); USING(rsa_n);
+
+ in = d0_iobuf_open_read(inbuf, inbuflen);
+
+ if(is_first)
+ {
+ if(recv_modulus)
+ {
+ CHECK_ASSIGN(ctx->schnorr_G, d0_iobuf_read_bignum(in, ctx->schnorr_G));
+ CHECK(d0_bignum_cmp(ctx->schnorr_G, zero) > 0);
+ CHECK(d0_bignum_cmp(ctx->schnorr_G, ctx->rsa_n) < 0);
+ }
+ CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_g_to_s));
+ CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, zero) >= 0);
+ CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, ctx->schnorr_G) < 0);
+ CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_H_g_to_s_signature));
+ CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero) >= 0);
+ 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!
+ 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(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));
+
+ // hash complete
+ if(d0_bignum_cmp(temp0, temp1))
+ {
+ // accept the key anyway, but mark as failed signature! will later return 0 in status
+ CHECK(d0_bignum_zero(ctx->schnorr_H_g_to_s_signature));
+ }
+ }
+
+ 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|
+ if(with_msg)
+ CHECK(d0_iobuf_read_packet(in, msg, msglen));
+
+ // VERIFY: g^x * (g^s)^-e = g^(x - s*e) = g^r
+
+ // verify schnorr ID scheme
+ // we need g^r = g^x (g^s)^e
+ CHECK(d0_bignum_mod_pow(temp2, four, temp1, ctx->schnorr_G));
+#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL
+ CHECK(d0_bignum_mod_inv(temp3, ctx->schnorr_g_to_s, ctx->schnorr_G));
+ CHECK(d0_bignum_mod_pow(temp1, temp3, temp0, ctx->schnorr_G));
+#else
+ CHECK(d0_bignum_mod_pow(temp1, ctx->schnorr_g_to_s, temp0, ctx->schnorr_G));
+#endif
+ 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_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, 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);
+
+ d0_iobuf_close(in, NULL);
+ 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 n, sz;
+ size_t sz, n;
+ char shabuf[32];
- USING(r); USING(other_4_to_r); USING(schnorr_G);
+ USING(rsa_n);
+ USING(rsa_e);
+ USING(schnorr_g_to_s);
out = d0_iobuf_open_write(outbuf, *outbuflen);
conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));
- // temps: temp0 result
- CHECK(d0_bignum_mod_pow(temp0, ctx->other_4_to_r, ctx->r, ctx->schnorr_G));
- CHECK(d0_iobuf_write_bignum(conv, temp0));
+ CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_n));
+ CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_e));
+ CHECK(d0_iobuf_write_bignum(conv, ctx->schnorr_g_to_s));
CHECK(d0_iobuf_close(conv, &sz));
conv = NULL;
- n = *outbuflen;
+ 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);
return 0;
}
+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);
+
+ LOCKTEMPS();
+ CHECK(d0_bignum_mod_pow(temp0, ctx->other_g_to_t, ctx->t, ctx->schnorr_G));
+ ret = d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen);
+ UNLOCKTEMPS();
+ return ret;
+
+fail:
+ UNLOCKTEMPS();
+ return 0;
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_verify_public_id(const d0_blind_id_t *ctx, D0_BOOL *status)
+{
+ unsigned char hashbuf[2048];
+ size_t sz;
+
+ USINGTEMPS(); // temps: temp0 temp1 temp2
+ USING(schnorr_H_g_to_s_signature); USING(rsa_e); USING(rsa_n); USING(schnorr_g_to_s);
+
+ if(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero))
+ {
+ // 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!
+ 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(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));
+
+ // hash complete
+ CHECK(d0_bignum_cmp(temp0, temp1) == 0);
+
+ *status = 1;
+ }
+ else
+ *status = 0;
+
+ UNLOCKTEMPS();
+ return 1;
+
+fail:
+ UNLOCKTEMPS();
+ return 0;
+}
+
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_verify_private_id(const d0_blind_id_t *ctx)
+{
+ USINGTEMPS(); // temps: temp0 = g^s
+ USING(schnorr_G); USING(schnorr_s); USING(schnorr_g_to_s);
+
+ LOCKTEMPS();
+ CHECK(d0_bignum_mod_pow(temp0, four, ctx->schnorr_s, ctx->schnorr_G));
+ CHECK(!d0_bignum_cmp(temp0, ctx->schnorr_g_to_s));
+ UNLOCKTEMPS();
+ return 1;
+
+fail:
+ UNLOCKTEMPS();
+ return 0;
+}
+
d0_blind_id_t *d0_blind_id_new(void)
{
d0_blind_id_t *b = d0_malloc(sizeof(d0_blind_id_t));
d0_blind_id_clear(a);
d0_free(a);
}
+
+void d0_blind_id_util_sha256(char *out, const char *in, size_t n)
+{
+ SHA256_CTX context;
+ SHA256_Init(&context);
+ 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);
+}