757 lines
21 KiB
C
757 lines
21 KiB
C
/* srp.c
|
|
*
|
|
* Copyright (C) 2006-2017 wolfSSL Inc.
|
|
*
|
|
* This file is part of wolfSSL.
|
|
*
|
|
* wolfSSL is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* wolfSSL 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
|
|
*/
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include <config.h>
|
|
#endif
|
|
|
|
#include <wolfssl/wolfcrypt/settings.h>
|
|
|
|
#ifdef WOLFCRYPT_HAVE_SRP
|
|
|
|
#include <wolfssl/wolfcrypt/srp.h>
|
|
#include <wolfssl/wolfcrypt/random.h>
|
|
#include <wolfssl/wolfcrypt/error-crypt.h>
|
|
|
|
#ifdef NO_INLINE
|
|
#include <wolfssl/wolfcrypt/misc.h>
|
|
#else
|
|
#define WOLFSSL_MISC_INCLUDED
|
|
#include <wolfcrypt/src/misc.c>
|
|
#endif
|
|
|
|
/** Computes the session key using the Mask Generation Function 1. */
|
|
static int wc_SrpSetKey(Srp* srp, byte* secret, word32 size);
|
|
|
|
static int SrpHashInit(SrpHash* hash, SrpType type)
|
|
{
|
|
hash->type = type;
|
|
|
|
switch (type) {
|
|
case SRP_TYPE_SHA:
|
|
#ifndef NO_SHA
|
|
return wc_InitSha(&hash->data.sha);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA256:
|
|
#ifndef NO_SHA256
|
|
return wc_InitSha256(&hash->data.sha256);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA384:
|
|
#ifdef WOLFSSL_SHA384
|
|
return wc_InitSha384(&hash->data.sha384);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA512:
|
|
#ifdef WOLFSSL_SHA512
|
|
return wc_InitSha512(&hash->data.sha512);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
default:
|
|
return BAD_FUNC_ARG;
|
|
}
|
|
}
|
|
|
|
static int SrpHashUpdate(SrpHash* hash, const byte* data, word32 size)
|
|
{
|
|
switch (hash->type) {
|
|
case SRP_TYPE_SHA:
|
|
#ifndef NO_SHA
|
|
return wc_ShaUpdate(&hash->data.sha, data, size);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA256:
|
|
#ifndef NO_SHA256
|
|
return wc_Sha256Update(&hash->data.sha256, data, size);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA384:
|
|
#ifdef WOLFSSL_SHA384
|
|
return wc_Sha384Update(&hash->data.sha384, data, size);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA512:
|
|
#ifdef WOLFSSL_SHA512
|
|
return wc_Sha512Update(&hash->data.sha512, data, size);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
default:
|
|
return BAD_FUNC_ARG;
|
|
}
|
|
}
|
|
|
|
static int SrpHashFinal(SrpHash* hash, byte* digest)
|
|
{
|
|
switch (hash->type) {
|
|
case SRP_TYPE_SHA:
|
|
#ifndef NO_SHA
|
|
return wc_ShaFinal(&hash->data.sha, digest);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA256:
|
|
#ifndef NO_SHA256
|
|
return wc_Sha256Final(&hash->data.sha256, digest);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA384:
|
|
#ifdef WOLFSSL_SHA384
|
|
return wc_Sha384Final(&hash->data.sha384, digest);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA512:
|
|
#ifdef WOLFSSL_SHA512
|
|
return wc_Sha512Final(&hash->data.sha512, digest);
|
|
#else
|
|
return BAD_FUNC_ARG;
|
|
#endif
|
|
|
|
default:
|
|
return BAD_FUNC_ARG;
|
|
}
|
|
}
|
|
|
|
static word32 SrpHashSize(SrpType type)
|
|
{
|
|
switch (type) {
|
|
case SRP_TYPE_SHA:
|
|
#ifndef NO_SHA
|
|
return WC_SHA_DIGEST_SIZE;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA256:
|
|
#ifndef NO_SHA256
|
|
return WC_SHA256_DIGEST_SIZE;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA384:
|
|
#ifdef WOLFSSL_SHA384
|
|
return WC_SHA384_DIGEST_SIZE;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA512:
|
|
#ifdef WOLFSSL_SHA512
|
|
return WC_SHA512_DIGEST_SIZE;
|
|
#else
|
|
return 0;
|
|
#endif
|
|
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
int wc_SrpInit(Srp* srp, SrpType type, SrpSide side)
|
|
{
|
|
int r;
|
|
|
|
/* validating params */
|
|
|
|
if (!srp)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (side != SRP_CLIENT_SIDE && side != SRP_SERVER_SIDE)
|
|
return BAD_FUNC_ARG;
|
|
|
|
switch (type) {
|
|
case SRP_TYPE_SHA:
|
|
#ifdef NO_SHA
|
|
return NOT_COMPILED_IN;
|
|
#else
|
|
break; /* OK */
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA256:
|
|
#ifdef NO_SHA256
|
|
return NOT_COMPILED_IN;
|
|
#else
|
|
break; /* OK */
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA384:
|
|
#ifndef WOLFSSL_SHA384
|
|
return NOT_COMPILED_IN;
|
|
#else
|
|
break; /* OK */
|
|
#endif
|
|
|
|
case SRP_TYPE_SHA512:
|
|
#ifndef WOLFSSL_SHA512
|
|
return NOT_COMPILED_IN;
|
|
#else
|
|
break; /* OK */
|
|
#endif
|
|
|
|
default:
|
|
return BAD_FUNC_ARG;
|
|
}
|
|
|
|
/* initializing variables */
|
|
|
|
XMEMSET(srp, 0, sizeof(Srp));
|
|
|
|
if ((r = SrpHashInit(&srp->client_proof, type)) != 0)
|
|
return r;
|
|
|
|
if ((r = SrpHashInit(&srp->server_proof, type)) != 0)
|
|
return r;
|
|
|
|
if ((r = mp_init_multi(&srp->N, &srp->g, &srp->auth,
|
|
&srp->priv, 0, 0)) != 0)
|
|
return r;
|
|
|
|
srp->side = side; srp->type = type;
|
|
srp->salt = NULL; srp->saltSz = 0;
|
|
srp->user = NULL; srp->userSz = 0;
|
|
srp->key = NULL; srp->keySz = 0;
|
|
|
|
srp->keyGenFunc_cb = wc_SrpSetKey;
|
|
|
|
/* default heap hint to NULL or test value */
|
|
#ifdef WOLFSSL_HEAP_TEST
|
|
srp->heap = (void*)WOLFSSL_HEAP_TEST;
|
|
#else
|
|
srp->heap = NULL;
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
void wc_SrpTerm(Srp* srp)
|
|
{
|
|
if (srp) {
|
|
mp_clear(&srp->N); mp_clear(&srp->g);
|
|
mp_clear(&srp->auth); mp_clear(&srp->priv);
|
|
if (srp->salt) {
|
|
ForceZero(srp->salt, srp->saltSz);
|
|
XFREE(srp->salt, srp->heap, DYNAMIC_TYPE_SRP);
|
|
}
|
|
if (srp->user) {
|
|
ForceZero(srp->user, srp->userSz);
|
|
XFREE(srp->user, srp->heap, DYNAMIC_TYPE_SRP);
|
|
}
|
|
if (srp->key) {
|
|
ForceZero(srp->key, srp->keySz);
|
|
XFREE(srp->key, srp->heap, DYNAMIC_TYPE_SRP);
|
|
}
|
|
|
|
ForceZero(srp, sizeof(Srp));
|
|
}
|
|
}
|
|
|
|
int wc_SrpSetUsername(Srp* srp, const byte* username, word32 size)
|
|
{
|
|
if (!srp || !username)
|
|
return BAD_FUNC_ARG;
|
|
|
|
srp->user = (byte*)XMALLOC(size, srp->heap, DYNAMIC_TYPE_SRP);
|
|
if (srp->user == NULL)
|
|
return MEMORY_E;
|
|
|
|
srp->userSz = size;
|
|
XMEMCPY(srp->user, username, srp->userSz);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int wc_SrpSetParams(Srp* srp, const byte* N, word32 nSz,
|
|
const byte* g, word32 gSz,
|
|
const byte* salt, word32 saltSz)
|
|
{
|
|
SrpHash hash;
|
|
byte digest1[SRP_MAX_DIGEST_SIZE];
|
|
byte digest2[SRP_MAX_DIGEST_SIZE];
|
|
byte pad = 0;
|
|
int i, r;
|
|
int j = 0;
|
|
|
|
if (!srp || !N || !g || !salt || nSz < gSz)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (!srp->user)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
/* Set N */
|
|
if (mp_read_unsigned_bin(&srp->N, N, nSz) != MP_OKAY)
|
|
return MP_READ_E;
|
|
|
|
if (mp_count_bits(&srp->N) < SRP_MODULUS_MIN_BITS)
|
|
return BAD_FUNC_ARG;
|
|
|
|
/* Set g */
|
|
if (mp_read_unsigned_bin(&srp->g, g, gSz) != MP_OKAY)
|
|
return MP_READ_E;
|
|
|
|
if (mp_cmp(&srp->N, &srp->g) != MP_GT)
|
|
return BAD_FUNC_ARG;
|
|
|
|
/* Set salt */
|
|
if (srp->salt) {
|
|
ForceZero(srp->salt, srp->saltSz);
|
|
XFREE(srp->salt, srp->heap, DYNAMIC_TYPE_SRP);
|
|
}
|
|
|
|
srp->salt = (byte*)XMALLOC(saltSz, srp->heap, DYNAMIC_TYPE_SRP);
|
|
if (srp->salt == NULL)
|
|
return MEMORY_E;
|
|
|
|
XMEMCPY(srp->salt, salt, saltSz);
|
|
srp->saltSz = saltSz;
|
|
|
|
/* Set k = H(N, g) */
|
|
r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, (byte*) N, nSz);
|
|
for (i = 0; (word32)i < nSz - gSz; i++) {
|
|
if (!r) r = SrpHashUpdate(&hash, &pad, 1);
|
|
}
|
|
if (!r) r = SrpHashUpdate(&hash, (byte*) g, gSz);
|
|
if (!r) r = SrpHashFinal(&hash, srp->k);
|
|
|
|
/* update client proof */
|
|
|
|
/* digest1 = H(N) */
|
|
if (!r) r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, (byte*) N, nSz);
|
|
if (!r) r = SrpHashFinal(&hash, digest1);
|
|
|
|
/* digest2 = H(g) */
|
|
if (!r) r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, (byte*) g, gSz);
|
|
if (!r) r = SrpHashFinal(&hash, digest2);
|
|
|
|
/* digest1 = H(N) ^ H(g) */
|
|
if (r == 0) {
|
|
for (i = 0, j = SrpHashSize(srp->type); i < j; i++)
|
|
digest1[i] ^= digest2[i];
|
|
}
|
|
|
|
/* digest2 = H(user) */
|
|
if (!r) r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, srp->user, srp->userSz);
|
|
if (!r) r = SrpHashFinal(&hash, digest2);
|
|
|
|
/* client proof = H( H(N) ^ H(g) | H(user) | salt) */
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, digest1, j);
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, digest2, j);
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, salt, saltSz);
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpSetPassword(Srp* srp, const byte* password, word32 size)
|
|
{
|
|
SrpHash hash;
|
|
byte digest[SRP_MAX_DIGEST_SIZE];
|
|
word32 digestSz;
|
|
int r;
|
|
|
|
if (!srp || !password || srp->side != SRP_CLIENT_SIDE)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (!srp->salt)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
digestSz = SrpHashSize(srp->type);
|
|
|
|
/* digest = H(username | ':' | password) */
|
|
r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, srp->user, srp->userSz);
|
|
if (!r) r = SrpHashUpdate(&hash, (const byte*) ":", 1);
|
|
if (!r) r = SrpHashUpdate(&hash, password, size);
|
|
if (!r) r = SrpHashFinal(&hash, digest);
|
|
|
|
/* digest = H(salt | H(username | ':' | password)) */
|
|
if (!r) r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, srp->salt, srp->saltSz);
|
|
if (!r) r = SrpHashUpdate(&hash, digest, digestSz);
|
|
if (!r) r = SrpHashFinal(&hash, digest);
|
|
|
|
/* Set x (private key) */
|
|
if (!r) r = mp_read_unsigned_bin(&srp->auth, digest, digestSz);
|
|
|
|
ForceZero(digest, SRP_MAX_DIGEST_SIZE);
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpGetVerifier(Srp* srp, byte* verifier, word32* size)
|
|
{
|
|
mp_int v;
|
|
int r;
|
|
|
|
if (!srp || !verifier || !size || srp->side != SRP_CLIENT_SIDE)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (mp_iszero(&srp->auth) == MP_YES)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
r = mp_init(&v);
|
|
if (r != MP_OKAY)
|
|
return MP_INIT_E;
|
|
|
|
/* v = g ^ x % N */
|
|
if (!r) r = mp_exptmod(&srp->g, &srp->auth, &srp->N, &v);
|
|
if (!r) r = *size < (word32)mp_unsigned_bin_size(&v) ? BUFFER_E : MP_OKAY;
|
|
if (!r) r = mp_to_unsigned_bin(&v, verifier);
|
|
if (!r) *size = mp_unsigned_bin_size(&v);
|
|
|
|
mp_clear(&v);
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpSetVerifier(Srp* srp, const byte* verifier, word32 size)
|
|
{
|
|
if (!srp || !verifier || srp->side != SRP_SERVER_SIDE)
|
|
return BAD_FUNC_ARG;
|
|
|
|
return mp_read_unsigned_bin(&srp->auth, verifier, size);
|
|
}
|
|
|
|
int wc_SrpSetPrivate(Srp* srp, const byte* priv, word32 size)
|
|
{
|
|
mp_int p;
|
|
int r;
|
|
|
|
if (!srp || !priv || !size)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (mp_iszero(&srp->auth) == MP_YES)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
r = mp_init(&p);
|
|
if (r != MP_OKAY)
|
|
return MP_INIT_E;
|
|
if (!r) r = mp_read_unsigned_bin(&p, priv, size);
|
|
if (!r) r = mp_mod(&p, &srp->N, &srp->priv);
|
|
if (!r) r = mp_iszero(&srp->priv) == MP_YES ? SRP_BAD_KEY_E : 0;
|
|
|
|
mp_clear(&p);
|
|
|
|
return r;
|
|
}
|
|
|
|
/** Generates random data using wolfcrypt RNG. */
|
|
static int wc_SrpGenPrivate(Srp* srp, byte* priv, word32 size)
|
|
{
|
|
WC_RNG rng;
|
|
int r = wc_InitRng(&rng);
|
|
|
|
if (!r) r = wc_RNG_GenerateBlock(&rng, priv, size);
|
|
if (!r) r = wc_SrpSetPrivate(srp, priv, size);
|
|
if (!r) wc_FreeRng(&rng);
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpGetPublic(Srp* srp, byte* pub, word32* size)
|
|
{
|
|
mp_int pubkey;
|
|
word32 modulusSz;
|
|
int r;
|
|
|
|
if (!srp || !pub || !size)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (mp_iszero(&srp->auth) == MP_YES)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
modulusSz = mp_unsigned_bin_size(&srp->N);
|
|
if (*size < modulusSz)
|
|
return BUFFER_E;
|
|
|
|
r = mp_init(&pubkey);
|
|
if (r != MP_OKAY)
|
|
return MP_INIT_E;
|
|
|
|
/* priv = random() */
|
|
if (mp_iszero(&srp->priv) == MP_YES)
|
|
r = wc_SrpGenPrivate(srp, pub, SRP_PRIVATE_KEY_MIN_BITS / 8);
|
|
|
|
/* client side: A = g ^ a % N */
|
|
if (srp->side == SRP_CLIENT_SIDE) {
|
|
if (!r) r = mp_exptmod(&srp->g, &srp->priv, &srp->N, &pubkey);
|
|
|
|
/* server side: B = (k * v + (g ^ b % N)) % N */
|
|
} else {
|
|
mp_int i, j;
|
|
|
|
if (mp_init_multi(&i, &j, 0, 0, 0, 0) == MP_OKAY) {
|
|
if (!r) r = mp_read_unsigned_bin(&i, srp->k,SrpHashSize(srp->type));
|
|
if (!r) r = mp_iszero(&i) == MP_YES ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_exptmod(&srp->g, &srp->priv, &srp->N, &pubkey);
|
|
if (!r) r = mp_mulmod(&i, &srp->auth, &srp->N, &j);
|
|
if (!r) r = mp_add(&j, &pubkey, &i);
|
|
if (!r) r = mp_mod(&i, &srp->N, &pubkey);
|
|
|
|
mp_clear(&i); mp_clear(&j);
|
|
}
|
|
}
|
|
|
|
/* extract public key to buffer */
|
|
XMEMSET(pub, 0, modulusSz);
|
|
if (!r) r = mp_to_unsigned_bin(&pubkey, pub);
|
|
if (!r) *size = mp_unsigned_bin_size(&pubkey);
|
|
mp_clear(&pubkey);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int wc_SrpSetKey(Srp* srp, byte* secret, word32 size)
|
|
{
|
|
SrpHash hash;
|
|
byte digest[SRP_MAX_DIGEST_SIZE];
|
|
word32 i, j, digestSz = SrpHashSize(srp->type);
|
|
byte counter[4];
|
|
int r = BAD_FUNC_ARG;
|
|
|
|
XMEMSET(digest, 0, SRP_MAX_DIGEST_SIZE);
|
|
|
|
srp->key = (byte*)XMALLOC(2 * digestSz, srp->heap, DYNAMIC_TYPE_SRP);
|
|
if (srp->key == NULL)
|
|
return MEMORY_E;
|
|
|
|
srp->keySz = 2 * digestSz;
|
|
|
|
for (i = j = 0; j < srp->keySz; i++) {
|
|
counter[0] = (i >> 24) & 0xFF;
|
|
counter[1] = (i >> 16) & 0xFF;
|
|
counter[2] = (i >> 8) & 0xFF;
|
|
counter[3] = i & 0xFF;
|
|
|
|
r = SrpHashInit(&hash, srp->type);
|
|
if (!r) r = SrpHashUpdate(&hash, secret, size);
|
|
if (!r) r = SrpHashUpdate(&hash, counter, 4);
|
|
|
|
if (j + digestSz > srp->keySz) {
|
|
if (!r) r = SrpHashFinal(&hash, digest);
|
|
XMEMCPY(srp->key + j, digest, srp->keySz - j);
|
|
j = srp->keySz;
|
|
}
|
|
else {
|
|
if (!r) r = SrpHashFinal(&hash, srp->key + j);
|
|
j += digestSz;
|
|
}
|
|
}
|
|
|
|
ForceZero(digest, sizeof(digest));
|
|
ForceZero(&hash, sizeof(SrpHash));
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpComputeKey(Srp* srp, byte* clientPubKey, word32 clientPubKeySz,
|
|
byte* serverPubKey, word32 serverPubKeySz)
|
|
{
|
|
SrpHash hash;
|
|
byte *secret;
|
|
byte digest[SRP_MAX_DIGEST_SIZE];
|
|
word32 i, secretSz, digestSz;
|
|
mp_int u, s, temp1, temp2;
|
|
byte pad = 0;
|
|
int r;
|
|
|
|
/* validating params */
|
|
|
|
if (!srp || !clientPubKey || clientPubKeySz == 0
|
|
|| !serverPubKey || serverPubKeySz == 0)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (mp_iszero(&srp->priv) == MP_YES)
|
|
return SRP_CALL_ORDER_E;
|
|
|
|
/* initializing variables */
|
|
|
|
if ((r = SrpHashInit(&hash, srp->type)) != 0)
|
|
return r;
|
|
|
|
digestSz = SrpHashSize(srp->type);
|
|
secretSz = mp_unsigned_bin_size(&srp->N);
|
|
|
|
if ((secret = (byte*)XMALLOC(secretSz, srp->heap, DYNAMIC_TYPE_SRP)) ==NULL)
|
|
return MEMORY_E;
|
|
|
|
if ((r = mp_init_multi(&u, &s, &temp1, &temp2, 0, 0)) != MP_OKAY) {
|
|
XFREE(secret, srp->heap, DYNAMIC_TYPE_SRP);
|
|
return r;
|
|
}
|
|
|
|
/* building u (random scrambling parameter) */
|
|
|
|
/* H(A) */
|
|
for (i = 0; !r && i < secretSz - clientPubKeySz; i++)
|
|
r = SrpHashUpdate(&hash, &pad, 1);
|
|
if (!r) r = SrpHashUpdate(&hash, clientPubKey, clientPubKeySz);
|
|
|
|
/* H(A | B) */
|
|
for (i = 0; !r && i < secretSz - serverPubKeySz; i++)
|
|
r = SrpHashUpdate(&hash, &pad, 1);
|
|
if (!r) r = SrpHashUpdate(&hash, serverPubKey, serverPubKeySz);
|
|
|
|
/* set u */
|
|
if (!r) r = SrpHashFinal(&hash, digest);
|
|
if (!r) r = mp_read_unsigned_bin(&u, digest, SrpHashSize(srp->type));
|
|
|
|
/* building s (secret) */
|
|
|
|
if (!r && srp->side == SRP_CLIENT_SIDE) {
|
|
|
|
/* temp1 = B - k * v; rejects k == 0, B == 0 and B >= N. */
|
|
r = mp_read_unsigned_bin(&temp1, srp->k, digestSz);
|
|
if (!r) r = mp_iszero(&temp1) == MP_YES ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_exptmod(&srp->g, &srp->auth, &srp->N, &temp2);
|
|
if (!r) r = mp_mulmod(&temp1, &temp2, &srp->N, &s);
|
|
if (!r) r = mp_read_unsigned_bin(&temp2, serverPubKey, serverPubKeySz);
|
|
if (!r) r = mp_iszero(&temp2) == MP_YES ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_cmp(&temp2, &srp->N) != MP_LT ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_sub(&temp2, &s, &temp1);
|
|
|
|
/* temp2 = a + u * x */
|
|
if (!r) r = mp_mulmod(&u, &srp->auth, &srp->N, &s);
|
|
if (!r) r = mp_add(&srp->priv, &s, &temp2);
|
|
|
|
/* secret = temp1 ^ temp2 % N */
|
|
if (!r) r = mp_exptmod(&temp1, &temp2, &srp->N, &s);
|
|
|
|
} else if (!r && srp->side == SRP_SERVER_SIDE) {
|
|
/* temp1 = v ^ u % N */
|
|
r = mp_exptmod(&srp->auth, &u, &srp->N, &temp1);
|
|
|
|
/* temp2 = A * temp1 % N; rejects A == 0, A >= N */
|
|
if (!r) r = mp_read_unsigned_bin(&s, clientPubKey, clientPubKeySz);
|
|
if (!r) r = mp_iszero(&s) == MP_YES ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_cmp(&s, &srp->N) != MP_LT ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_mulmod(&s, &temp1, &srp->N, &temp2);
|
|
|
|
/* rejects A * v ^ u % N >= 1, A * v ^ u % N == -1 % N */
|
|
if (!r) r = mp_read_unsigned_bin(&temp1, (const byte*)"\001", 1);
|
|
if (!r) r = mp_cmp(&temp2, &temp1) != MP_GT ? SRP_BAD_KEY_E : 0;
|
|
if (!r) r = mp_sub(&srp->N, &temp1, &s);
|
|
if (!r) r = mp_cmp(&temp2, &s) == MP_EQ ? SRP_BAD_KEY_E : 0;
|
|
|
|
/* secret = temp2 * b % N */
|
|
if (!r) r = mp_exptmod(&temp2, &srp->priv, &srp->N, &s);
|
|
}
|
|
|
|
/* building session key from secret */
|
|
|
|
if (!r) r = mp_to_unsigned_bin(&s, secret);
|
|
if (!r) r = srp->keyGenFunc_cb(srp, secret, mp_unsigned_bin_size(&s));
|
|
|
|
/* updating client proof = H( H(N) ^ H(g) | H(user) | salt | A | B | K) */
|
|
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, clientPubKey, clientPubKeySz);
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, serverPubKey, serverPubKeySz);
|
|
if (!r) r = SrpHashUpdate(&srp->client_proof, srp->key, srp->keySz);
|
|
|
|
/* updating server proof = H(A) */
|
|
|
|
if (!r) r = SrpHashUpdate(&srp->server_proof, clientPubKey, clientPubKeySz);
|
|
|
|
XFREE(secret, srp->heap, DYNAMIC_TYPE_SRP);
|
|
mp_clear(&u); mp_clear(&s); mp_clear(&temp1); mp_clear(&temp2);
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpGetProof(Srp* srp, byte* proof, word32* size)
|
|
{
|
|
int r;
|
|
|
|
if (!srp || !proof || !size)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (*size < SrpHashSize(srp->type))
|
|
return BUFFER_E;
|
|
|
|
if ((r = SrpHashFinal(srp->side == SRP_CLIENT_SIDE
|
|
? &srp->client_proof
|
|
: &srp->server_proof, proof)) != 0)
|
|
return r;
|
|
|
|
*size = SrpHashSize(srp->type);
|
|
|
|
if (srp->side == SRP_CLIENT_SIDE) {
|
|
/* server proof = H( A | client proof | K) */
|
|
if (!r) r = SrpHashUpdate(&srp->server_proof, proof, *size);
|
|
if (!r) r = SrpHashUpdate(&srp->server_proof, srp->key, srp->keySz);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
int wc_SrpVerifyPeersProof(Srp* srp, byte* proof, word32 size)
|
|
{
|
|
byte digest[SRP_MAX_DIGEST_SIZE];
|
|
int r;
|
|
|
|
if (!srp || !proof)
|
|
return BAD_FUNC_ARG;
|
|
|
|
if (size != SrpHashSize(srp->type))
|
|
return BUFFER_E;
|
|
|
|
r = SrpHashFinal(srp->side == SRP_CLIENT_SIDE ? &srp->server_proof
|
|
: &srp->client_proof, digest);
|
|
|
|
if (srp->side == SRP_SERVER_SIDE) {
|
|
/* server proof = H( A | client proof | K) */
|
|
if (!r) r = SrpHashUpdate(&srp->server_proof, proof, size);
|
|
if (!r) r = SrpHashUpdate(&srp->server_proof, srp->key, srp->keySz);
|
|
}
|
|
|
|
if (!r && XMEMCMP(proof, digest, size) != 0)
|
|
r = SRP_VERIFY_E;
|
|
|
|
return r;
|
|
}
|
|
|
|
#endif /* WOLFCRYPT_HAVE_SRP */
|