/* * Secure Remote Password 6a implementation * Copyright (c) 2010 Tom Cocagne. All rights reserved. * https://github.com/cocagne/csrp * * The MIT License (MIT) * * Copyright (c) 2013 Tom Cocagne * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies * of the Software, and to permit persons to whom the Software is furnished to do * so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * *=========================================================================== * updated (2023) by fduncanh to replace deprecated openssl SHA* hash functions * modified (2023) by fduncanh for use with Apple's pair-setup-pin protocol */ #define APPLE_VARIANT #ifdef WIN32 # include # include #else # include #endif #include #include #include #include #include #include #include #include #include #include #include "srp.h" static int g_initialized = 0; typedef struct { BIGNUM * N; BIGNUM * g; } NGConstant; struct NGHex { const char * n_hex; const char * g_hex; }; /* All constants here were pulled from Appendix A of RFC 5054 */ static struct NGHex global_Ng_constants[] = { #if 0 /* begin removed section 1 */ { /* 1024 */ "EEAF0AB9ADB38DD69C33F80AFA8FC5E86072618775FF3C0B9EA2314C9C256576D674DF7496" "EA81D3383B4813D692C6E0E0D5D8E250B98BE48E495C1D6089DAD15DC7D7B46154D6B6CE8E" "F4AD69B15D4982559B297BCF1885C529F566660E57EC68EDBC3C05726CC02FD4CBF4976EAA" "9AFD5138FE8376435B9FC61D2FC0EB06E3", "2" }, { /* 1536 */ "9DEF3CAFB939277AB1F12A8617A47BBBDBA51DF499AC4C80BEEEA961" "4B19CC4D5F4F5F556E27CBDE51C6A94BE4607A291558903BA0D0F843" "80B655BB9A22E8DCDF028A7CEC67F0D08134B1C8B97989149B609E0B" "E3BAB63D47548381DBC5B1FC764E3F4B53DD9DA1158BFD3E2B9C8CF5" "6EDF019539349627DB2FD53D24B7C48665772E437D6C7F8CE442734A" "F7CCB7AE837C264AE3A9BEB87F8A2FE9B8B5292E5A021FFF5E91479E" "8CE7A28C2442C6F315180F93499A234DCF76E3FED135F9BB", "2" }, #endif /* end removed section 1 */ { /* 2048 */ "AC6BDB41324A9A9BF166DE5E1389582FAF72B6651987EE07FC3192943DB56050A37329CBB4" "A099ED8193E0757767A13DD52312AB4B03310DCD7F48A9DA04FD50E8083969EDB767B0CF60" "95179A163AB3661A05FBD5FAAAE82918A9962F0B93B855F97993EC975EEAA80D740ADBF4FF" "747359D041D5C33EA71D281E446B14773BCA97B43A23FB801676BD207A436C6481F1D2B907" "8717461A5B9D32E688F87748544523B524B0D57D5EA77A2775D2ECFA032CFBDBF52FB37861" "60279004E57AE6AF874E7303CE53299CCC041C7BC308D82A5698F3A8D0C38271AE35F8E9DB" "FBB694B5C803D89F7AE435DE236D525F54759B65E372FCD68EF20FA7111F9E4AFF73", "2" }, #if 0 /* begin removed section 2 */ {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}, {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}, {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}, {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}, #endif /* end removed section 2 */ {0,0} /* null sentinel */ }; static NGConstant * new_ng( SRP_NGType ng_type, const char * n_hex, const char * g_hex ) { NGConstant * ng = (NGConstant *) malloc( sizeof(NGConstant) ); ng->N = BN_new(); ng->g = BN_new(); if( !ng || !ng->N || !ng->g ) return 0; if ( ng_type != SRP_NG_CUSTOM ) { int idx = ng_type; if ( ng_type > SRP_NG_CUSTOM ) idx -= 1; n_hex = global_Ng_constants[ idx ].n_hex; g_hex = global_Ng_constants[ idx ].g_hex; } BN_hex2bn( &ng->N, n_hex ); BN_hex2bn( &ng->g, g_hex ); return ng; } static void delete_ng( NGConstant * ng ) { if (ng) { BN_free( ng->N ); BN_free( ng->g ); ng->N = 0; ng->g = 0; free(ng); } } typedef struct HashCTX_s { EVP_MD_CTX *digest_ctx; } HashCTX_t; struct SRPVerifier { SRP_HashAlgorithm hash_alg; NGConstant *ng; const char * username; const unsigned char * bytes_B; int authenticated; int rfc5054; unsigned char M [SHA512_DIGEST_LENGTH]; unsigned char H_AMK [SHA512_DIGEST_LENGTH]; #ifdef APPLE_VARIANT unsigned char session_key [2 * SHA512_DIGEST_LENGTH]; #else unsigned char session_key [SHA512_DIGEST_LENGTH]; #endif }; #if 0 /*begin removed section 3*/ struct SRPUser { SRP_HashAlgorithm hash_alg; NGConstant *ng; BIGNUM *a; BIGNUM *A; BIGNUM *S; const unsigned char * bytes_A; int authenticated; int rfc5054; const char * username; const unsigned char * password; int password_len; unsigned char M [SHA512_DIGEST_LENGTH]; unsigned char H_AMK [SHA512_DIGEST_LENGTH]; #ifdef APPLE_VARIANT unsigned char session_key [2 * SHA512_DIGEST_LENGTH]; #else unsigned char session_key [SHA512_DIGEST_LENGTH]; #endif }; #endif /*end removed section 3*/ static void handle_error(const char* location) { long error = ERR_get_error(); const char* error_str = ERR_error_string(error, NULL); fprintf(stderr, "SRP error at %s: %s\n", location, error_str); exit(EXIT_FAILURE); } static void hash_destroy( HashCTX_t *ctx) { if (ctx) { EVP_MD_CTX_free(ctx->digest_ctx); free(ctx); } } static HashCTX_t *hash_create() { HashCTX_t *ctx = (HashCTX_t *) malloc(sizeof(HashCTX_t)); assert(ctx != NULL); ctx->digest_ctx = EVP_MD_CTX_new(); assert(ctx->digest_ctx != NULL); return ctx; } int hash_reset( HashCTX_t *ctx) { return EVP_MD_CTX_reset( ctx->digest_ctx); } static int hash_init( SRP_HashAlgorithm alg, HashCTX_t *ctx) { int ret; switch (alg) { case SRP_SHA1 : ret = EVP_DigestInit_ex(ctx->digest_ctx, EVP_sha1(), NULL); break; case SRP_SHA224 : ret = EVP_DigestInit_ex(ctx->digest_ctx, EVP_sha224(), NULL); break; case SRP_SHA256 : ret = EVP_DigestInit_ex(ctx->digest_ctx, EVP_sha256(), NULL); break; case SRP_SHA384 : ret = EVP_DigestInit_ex(ctx->digest_ctx, EVP_sha384(), NULL); break; case SRP_SHA512 : ret = EVP_DigestInit_ex(ctx->digest_ctx, EVP_sha512(), NULL); break; default: return -1; } return ret; } static int hash_update( SRP_HashAlgorithm alg, HashCTX_t *ctx, const void *data, size_t len ) { int ret = EVP_DigestUpdate(ctx->digest_ctx, data, len); if (!ret) { handle_error(__func__); } return ret; } static int hash_final( SRP_HashAlgorithm alg, HashCTX_t *ctx, unsigned char *md, unsigned int *md_len ) { int ret = EVP_DigestFinal_ex(ctx->digest_ctx, md, md_len); if (!ret) { handle_error(__func__); } return ret; } static unsigned char * hash( SRP_HashAlgorithm alg, const unsigned char *d, size_t n, unsigned char *md ) { switch (alg) { case SRP_SHA1 : return SHA1( d, n, md ); case SRP_SHA224: return SHA224( d, n, md ); case SRP_SHA256: return SHA256( d, n, md ); case SRP_SHA384: return SHA384( d, n, md ); case SRP_SHA512: return SHA512( d, n, md ); default: return 0; }; } static int hash_length( SRP_HashAlgorithm alg ) { switch (alg) { case SRP_SHA1 : return SHA_DIGEST_LENGTH; case SRP_SHA224: return SHA224_DIGEST_LENGTH; case SRP_SHA256: return SHA256_DIGEST_LENGTH; case SRP_SHA384: return SHA384_DIGEST_LENGTH; case SRP_SHA512: return SHA512_DIGEST_LENGTH; default: return -1; }; } static BIGNUM * H_nn_orig( SRP_HashAlgorithm alg, const BIGNUM * n1, const BIGNUM * n2 ) { unsigned char buff[ SHA512_DIGEST_LENGTH ]; int len_n1 = BN_num_bytes(n1); int len_n2 = BN_num_bytes(n2); int nbytes = len_n1 + len_n2; unsigned char * bin = (unsigned char *) malloc( nbytes ); if (!bin) return 0; BN_bn2bin(n1, bin); BN_bn2bin(n2, bin + len_n1); hash( alg, bin, nbytes, buff ); free(bin); return BN_bin2bn(buff, hash_length(alg), NULL); } static BIGNUM * H_nn_rfc5054( SRP_HashAlgorithm alg, const BIGNUM * N, const BIGNUM * n1, const BIGNUM * n2 ) { unsigned char buff[ SHA512_DIGEST_LENGTH ]; int len_N = BN_num_bytes(N); int len_n1 = BN_num_bytes(n1); int len_n2 = BN_num_bytes(n2); int nbytes = len_N * 2; unsigned char * bin = (unsigned char *) malloc( nbytes ); if (!bin) return 0; if (len_n1 > len_N || len_n2 > len_N) return 0; memset(bin, 0, nbytes); BN_bn2bin(n1, bin + (len_N - len_n1)); BN_bn2bin(n2, bin + (len_N + len_N - len_n2)); hash( alg, bin, nbytes, buff ); free(bin); return BN_bin2bn(buff, hash_length(alg), NULL); } static BIGNUM * H_ns( SRP_HashAlgorithm alg, const BIGNUM * n, const unsigned char * bytes, int len_bytes ) { unsigned char buff[ SHA512_DIGEST_LENGTH ]; int len_n = BN_num_bytes(n); int nbytes = len_n + len_bytes; unsigned char * bin = (unsigned char *) malloc( nbytes ); if (!bin) return 0; BN_bn2bin(n, bin); memcpy( bin + len_n, bytes, len_bytes ); hash( alg, bin, nbytes, buff ); free(bin); return BN_bin2bn(buff, hash_length(alg), NULL); } static BIGNUM * calculate_x( SRP_HashAlgorithm alg, const BIGNUM * salt, const char * username, const unsigned char * password, int password_len ) { unsigned char ucp_hash[SHA512_DIGEST_LENGTH]; unsigned int ucp_hash_len; HashCTX_t *ctx = hash_create(); hash_init( alg, ctx); hash_update( alg, ctx, username, strlen(username) ); hash_update( alg, ctx, ":", 1 ); hash_update( alg, ctx, password, password_len ); hash_final( alg, ctx, ucp_hash, &ucp_hash_len ); hash_destroy ( ctx); return H_ns( alg, salt, ucp_hash, hash_length(alg) ); } static void update_hash_n( SRP_HashAlgorithm alg, HashCTX_t *ctx, const BIGNUM * n ) { unsigned long len = BN_num_bytes(n); unsigned char * n_bytes = (unsigned char *) malloc( len ); if (!n_bytes) return; BN_bn2bin(n, n_bytes); hash_update(alg, ctx, n_bytes, len); free(n_bytes); } static void hash_num( SRP_HashAlgorithm alg, const BIGNUM * n, unsigned char * dest ) { int nbytes = BN_num_bytes(n); unsigned char * bin = (unsigned char *) malloc( nbytes ); if(!bin) return; BN_bn2bin(n, bin); hash( alg, bin, nbytes, dest ); free(bin); } #ifdef APPLE_VARIANT /* added for compatibility with Apple's modified srp * see https://htmlpreview.github.io/?https://github.com/philippe44/RAOP-Player/blob/master/doc/auth_protocol.html */ static int hash_session_key( SRP_HashAlgorithm alg, const BIGNUM * n, unsigned char * dest ) { HashCTX_t *ctx; int nbytes = BN_num_bytes(n); unsigned char * bin = (unsigned char *) malloc( nbytes ); unsigned char fourbytes[4] = { 0 }; //Apple's modified SRP protocol unsigned int len1, len2; if(!bin) return -1; BN_bn2bin(n, bin); ctx = hash_create(); hash_init(alg, ctx); hash_update( alg, ctx, bin, nbytes); hash_update( alg, ctx, fourbytes, sizeof(fourbytes)); hash_final( alg, ctx, dest, &len1); hash_reset( ctx); fourbytes[3] = 1; hash_init(alg, ctx); hash_update( alg, ctx, bin, nbytes); hash_update( alg, ctx, fourbytes, sizeof(fourbytes)); hash_final( alg, ctx, dest + len1, &len2); hash_destroy( ctx); free(bin); return len1 + len2; } #endif static void calculate_M( SRP_HashAlgorithm alg, NGConstant *ng, unsigned char * dest, const char * I, const BIGNUM * s, const BIGNUM * A, const BIGNUM * B, const unsigned char * K ) { unsigned char H_N[ SHA512_DIGEST_LENGTH ]; unsigned char H_g[ SHA512_DIGEST_LENGTH ]; unsigned char H_I[ SHA512_DIGEST_LENGTH ]; unsigned char H_xor[ SHA512_DIGEST_LENGTH ]; unsigned int dest_len; HashCTX_t *ctx; int i = 0; int hash_len = hash_length(alg); hash_num( alg, ng->N, H_N ); hash_num( alg, ng->g, H_g ); hash(alg, (const unsigned char *)I, strlen(I), H_I); for (i=0; i < hash_len; i++ ) H_xor[i] = H_N[i] ^ H_g[i]; ctx = hash_create(); hash_init( alg, ctx); hash_update( alg, ctx, H_xor, hash_len ); hash_update( alg, ctx, H_I, hash_len ); update_hash_n( alg, ctx, s ); update_hash_n( alg, ctx, A ); update_hash_n( alg, ctx, B ); #ifdef APPLE_VARIANT /* Apple's SRP session key length is 2 x hash_len */ hash_update( alg, ctx, K, 2 * hash_len ); #else hash_update( alg, ctx, K, hash_len ); #endif hash_final( alg, ctx, dest, &dest_len ); hash_destroy ( ctx); } static void calculate_H_AMK( SRP_HashAlgorithm alg, unsigned char *dest, const BIGNUM * A, const unsigned char * M, const unsigned char * K ) { HashCTX_t *ctx; unsigned int dest_len; ctx = hash_create(); hash_init( alg, ctx); update_hash_n( alg, ctx, A ); hash_update( alg, ctx, M, hash_length(alg) ); #ifdef APPLE_VARIANT hash_update( alg, ctx, K, 2 * hash_length(alg) ); #else hash_update( alg, ctx, K, hash_length(alg) ); #endif hash_final( alg, ctx, dest, &dest_len ); hash_destroy ( ctx); } static void init_random() { if (g_initialized) return; #ifdef WIN32 HCRYPTPROV wctx; #else FILE *fp = 0; #endif unsigned char buff[64]; #ifdef WIN32 CryptAcquireContext(&wctx, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT); CryptGenRandom(wctx, sizeof(buff), (BYTE*) buff); CryptReleaseContext(wctx, 0); g_initialized = 1; #else fp = fopen("/dev/urandom", "r"); if (fp) { size_t count = fread(buff, sizeof(buff), 1, fp); fclose(fp); if (count == 1) { g_initialized = 1; } } #endif if (g_initialized) RAND_seed( buff, sizeof(buff) ); } /*********************************************************************************************************** * * Exported Functions * ***********************************************************************************************************/ void srp_random_seed( const unsigned char * random_data, int data_length ) { g_initialized = 1; if (random_data) RAND_seed( random_data, data_length ); } void srp_create_salted_verification_key( SRP_HashAlgorithm alg, SRP_NGType ng_type, const char * username, const unsigned char * password, int len_password, const unsigned char ** bytes_s, int * len_s, const unsigned char ** bytes_v, int * len_v, const char * n_hex, const char * g_hex ) { BIGNUM * s = BN_new(); BIGNUM * v = BN_new(); BIGNUM * x = 0; BN_CTX * ctx = BN_CTX_new(); NGConstant * ng = new_ng( ng_type, n_hex, g_hex ); if( !s || !v || !ctx || !ng ) goto cleanup_and_exit; init_random(); /* Only happens once */ #ifdef APPLE_VARIANT //use a 16 byte salt BN_rand(s, 128, -1, 0); #else BN_rand(s, 32, -1, 0); #endif x = calculate_x( alg, s, username, password, len_password ); if( !x ) goto cleanup_and_exit; BN_mod_exp(v, ng->g, x, ng->N, ctx); *len_s = BN_num_bytes(s); *len_v = BN_num_bytes(v); *bytes_s = (const unsigned char *) malloc( *len_s ); *bytes_v = (const unsigned char *) malloc( *len_v ); if (!bytes_s || !bytes_v) goto cleanup_and_exit; BN_bn2bin(s, (unsigned char *) *bytes_s); BN_bn2bin(v, (unsigned char *) *bytes_v); cleanup_and_exit: delete_ng( ng ); BN_free(s); BN_free(v); BN_free(x); BN_CTX_free(ctx); } #ifdef APPLE_VARIANT /* Out: bytes_B, len_B, bytes_b, len_b * On failure, bytes_B and bytes_b will be set to NULL * len_B and len_will be set to 0 */ void srp_create_server_ephemeral_key( SRP_HashAlgorithm alg, SRP_NGType ng_type, const unsigned char * bytes_v, int len_v, const unsigned char * bytes_b, int len_b, const unsigned char ** bytes_B, int * len_B, const char * n_hex, const char * g_hex, int rfc5054_compat ) { BIGNUM *v = BN_bin2bn(bytes_v, len_v, NULL); BIGNUM *tmp1 = BN_new(); BIGNUM *tmp2 = BN_new(); BIGNUM *B = BN_new(); BIGNUM *b = BN_new(); BIGNUM *k = 0; BN_CTX *ctx = BN_CTX_new(); NGConstant *ng = new_ng( ng_type, n_hex, g_hex ); *len_B = 0; *bytes_B = 0; if( !v || !B || !b || !tmp1 || !tmp2 || !ctx || !ng ) goto cleanup_and_exit; b = BN_bin2bn(bytes_b, len_b, NULL); if (rfc5054_compat) k = H_nn_rfc5054(alg, ng->N, ng->N, ng->g); else k = H_nn_orig(alg, ng->N, ng->g); if(!k) goto cleanup_and_exit; /* B = kv + g^b */ if (rfc5054_compat) { BN_mod_mul(tmp1, k, v, ng->N, ctx); BN_mod_exp(tmp2, ng->g, b, ng->N, ctx); BN_mod_add(B, tmp1, tmp2, ng->N, ctx); } else { BN_mul(tmp1, k, v, ctx); BN_mod_exp(tmp2, ng->g, b, ng->N, ctx); BN_add(B, tmp1, tmp2); } *len_B = BN_num_bytes(B); *bytes_B = (const unsigned char *)malloc( *len_B ); BN_bn2bin( B, (unsigned char *) *bytes_B ); cleanup_and_exit: BN_free(v); if (k) BN_free(k); BN_free(B); BN_free(b); BN_free(tmp1); BN_free(tmp2); BN_CTX_free(ctx); } #endif /* Out: bytes_B, len_B. * * On failure, bytes_B will be set to NULL and len_B will be set to 0 */ struct SRPVerifier * srp_verifier_new( SRP_HashAlgorithm alg, SRP_NGType ng_type, const char * username, const unsigned char * bytes_s, int len_s, const unsigned char * bytes_v, int len_v, const unsigned char * bytes_A, int len_A, #ifdef APPLE_VARIANT const unsigned char * bytes_b, int len_b, #endif const unsigned char ** bytes_B, int * len_B, const char * n_hex, const char * g_hex, int rfc5054_compat ) { BIGNUM *s = BN_bin2bn(bytes_s, len_s, NULL); BIGNUM *v = BN_bin2bn(bytes_v, len_v, NULL); BIGNUM *A = BN_bin2bn(bytes_A, len_A, NULL); BIGNUM *u = 0; BIGNUM *B = BN_new(); BIGNUM *S = BN_new(); BIGNUM *b = BN_new(); BIGNUM *k = 0; BIGNUM *tmp1 = BN_new(); BIGNUM *tmp2 = BN_new(); BN_CTX *ctx = BN_CTX_new(); int ulen = strlen(username) + 1; NGConstant *ng = new_ng( ng_type, n_hex, g_hex ); struct SRPVerifier *ver = 0; *len_B = 0; *bytes_B = 0; if( !s || !v || !A || !B || !S || !b || !tmp1 || !tmp2 || !ctx || !ng ) goto cleanup_and_exit; ver = (struct SRPVerifier *) malloc( sizeof(struct SRPVerifier) ); if (!ver) goto cleanup_and_exit; init_random(); /* Only happens once */ ver->username = (char *) malloc( ulen ); ver->hash_alg = alg; ver->ng = ng; if (!ver->username) { free(ver); ver = 0; goto cleanup_and_exit; } memcpy( (char*)ver->username, username, ulen ); ver->authenticated = 0; ver->rfc5054 = rfc5054_compat; /* SRP-6a safety check */ BN_mod(tmp1, A, ng->N, ctx); if ( !BN_is_zero(tmp1) ) { #ifdef APPLE_VARIANT if ( !len_b || !bytes_b) { #endif BN_rand(b, 256, -1, 0); #ifdef APPLE_VARIANT } else { b = BN_bin2bn(bytes_b, len_b, NULL); } #endif if (rfc5054_compat) k = H_nn_rfc5054(alg, ng->N, ng->N, ng->g); else k = H_nn_orig(alg, ng->N, ng->g); if(!k) { free(ver); ver = 0; goto cleanup_and_exit; } /* B = kv + g^b */ if (rfc5054_compat) { BN_mod_mul(tmp1, k, v, ng->N, ctx); BN_mod_exp(tmp2, ng->g, b, ng->N, ctx); BN_mod_add(B, tmp1, tmp2, ng->N, ctx); } else { BN_mul(tmp1, k, v, ctx); BN_mod_exp(tmp2, ng->g, b, ng->N, ctx); BN_add(B, tmp1, tmp2); } if (rfc5054_compat) u = H_nn_rfc5054(alg, ng->N, A, B); else u = H_nn_orig(alg, A, B); if(!u) { free(ver); ver = 0; goto cleanup_and_exit; } /* S = (A *(v^u)) ^ b */ BN_mod_exp(tmp1, v, u, ng->N, ctx); BN_mul(tmp2, A, tmp1, ctx); BN_mod_exp(S, tmp2, b, ng->N, ctx); #ifdef APPLE_VARIANT hash_session_key(alg, S, ver->session_key); #else hash_num(alg, S, ver->session_key); #endif calculate_M( alg, ng, ver->M, username, s, A, B, ver->session_key ); calculate_H_AMK( alg, ver->H_AMK, A, ver->M, ver->session_key ); *len_B = BN_num_bytes(B); *bytes_B = (const unsigned char *)malloc( *len_B ); if( !((const unsigned char *)*bytes_B) ) { free( (void*) ver->username ); free( ver ); ver = 0; *len_B = 0; goto cleanup_and_exit; } BN_bn2bin( B, (unsigned char *) *bytes_B ); ver->bytes_B = *bytes_B; } else { free(ver); ver = 0; } cleanup_and_exit: BN_free(s); BN_free(v); BN_free(A); if (u) BN_free(u); if (k) BN_free(k); BN_free(B); BN_free(S); BN_free(b); BN_free(tmp1); BN_free(tmp2); BN_CTX_free(ctx); return ver; } void srp_verifier_delete( struct SRPVerifier * ver ) { if (ver) { delete_ng( ver->ng ); free( (char *) ver->username ); free( (unsigned char *) ver->bytes_B ); memset(ver, 0, sizeof(*ver)); free( ver ); } } int srp_verifier_is_authenticated( struct SRPVerifier * ver ) { return ver->authenticated; } const char * srp_verifier_get_username( struct SRPVerifier * ver ) { return ver->username; } const unsigned char * srp_verifier_get_session_key( struct SRPVerifier * ver, int * key_length ) { if (key_length) #ifdef APPLE_VARIANT *key_length = 2 * hash_length( ver->hash_alg ); #else *key_length = hash_length( ver->hash_alg ); #endif return ver->session_key; } int srp_verifier_get_session_key_length( struct SRPVerifier * ver ) { #ifdef APPLE_VARIANT return 2 * hash_length( ver->hash_alg ); #else return hash_length( ver->hash_alg ); #endif } /* user_M must be exactly SHA512_DIGEST_LENGTH bytes in size */ void srp_verifier_verify_session( struct SRPVerifier * ver, const unsigned char * user_M, const unsigned char ** bytes_HAMK ) { if ( memcmp( ver->M, user_M, hash_length(ver->hash_alg) ) == 0 ) { ver->authenticated = 1; *bytes_HAMK = ver->H_AMK; } else *bytes_HAMK = NULL; } /*******************************************************************************/ #if 0 /*begin removed section 4 */ struct SRPUser * srp_user_new( SRP_HashAlgorithm alg, SRP_NGType ng_type, const char * username, const unsigned char * bytes_password, int len_password, const char * n_hex, const char * g_hex, int rfc5054_compat ) { struct SRPUser *usr = (struct SRPUser *) malloc( sizeof(struct SRPUser) ); int ulen = strlen(username) + 1; if (!usr) goto err_exit; init_random(); /* Only happens once */ usr->hash_alg = alg; usr->ng = new_ng( ng_type, n_hex, g_hex ); usr->a = BN_new(); usr->A = BN_new(); usr->S = BN_new(); if (!usr->ng || !usr->a || !usr->A || !usr->S) goto err_exit; usr->username = (const char *) malloc(ulen); usr->password = (const unsigned char *) malloc(len_password); usr->password_len = len_password; if (!usr->username || !usr->password) goto err_exit; memcpy((char *)usr->username, username, ulen); memcpy((char *)usr->password, bytes_password, len_password); usr->authenticated = 0; usr->rfc5054 = rfc5054_compat; usr->bytes_A = 0; return usr; err_exit: if (usr) { BN_free(usr->a); BN_free(usr->A); BN_free(usr->S); if (usr->username) free((void*)usr->username); if (usr->password) { memset((void*)usr->password, 0, usr->password_len); free((void*)usr->password); } free(usr); } return 0; } void srp_user_delete( struct SRPUser * usr ) { if( usr ) { BN_free( usr->a ); BN_free( usr->A ); BN_free( usr->S ); delete_ng( usr->ng ); memset((void*)usr->password, 0, usr->password_len); free((char *)usr->username); free((char *)usr->password); if (usr->bytes_A) free( (char *)usr->bytes_A ); memset(usr, 0, sizeof(*usr)); free( usr ); } } int srp_user_is_authenticated( struct SRPUser * usr) { return usr->authenticated; } const char * srp_user_get_username( struct SRPUser * usr ) { return usr->username; } const unsigned char * srp_user_get_session_key( struct SRPUser * usr, int * key_length ) { if (key_length) #ifdef APPLE_VARIANT *key_length = 2 * hash_length( usr->hash_alg ); #else *key_length = hash_length( usr->hash_alg ); #endif return usr->session_key; } int srp_user_get_session_key_length( struct SRPUser * usr ) { #ifdef APPLE_VARIANT return 2 * hash_length( usr->hash_alg ); #else return hash_length( usr->hash_alg ); #endif } /* Output: username, bytes_A, len_A */ void srp_user_start_authentication( struct SRPUser * usr, const char ** username, const unsigned char ** bytes_A, int * len_A ) { BN_CTX *ctx = BN_CTX_new(); BN_rand(usr->a, 256, -1, 0); BN_mod_exp(usr->A, usr->ng->g, usr->a, usr->ng->N, ctx); BN_CTX_free(ctx); *len_A = BN_num_bytes(usr->A); *bytes_A = (const unsigned char *)malloc( *len_A ); if (!*bytes_A) { *len_A = 0; *bytes_A = 0; *username = 0; return; } BN_bn2bin( usr->A, (unsigned char *) *bytes_A ); usr->bytes_A = *bytes_A; *username = usr->username; } /* Output: bytes_M. Buffer length is SHA512_DIGEST_LENGTH */ void srp_user_process_challenge( struct SRPUser * usr, const unsigned char * bytes_s, int len_s, const unsigned char * bytes_B, int len_B, const unsigned char ** bytes_M, int * len_M) { BIGNUM *s = BN_bin2bn(bytes_s, len_s, NULL); BIGNUM *B = BN_bin2bn(bytes_B, len_B, NULL); BIGNUM *u = 0; BIGNUM *x = 0; BIGNUM *k = 0; BIGNUM *v = BN_new(); BIGNUM *tmp1 = BN_new(); BIGNUM *tmp2 = BN_new(); BIGNUM *tmp3 = BN_new(); BN_CTX *ctx = BN_CTX_new(); *len_M = 0; *bytes_M = 0; if( !s || !B || !v || !tmp1 || !tmp2 || !tmp3 || !ctx ) goto cleanup_and_exit; if (usr->rfc5054) u = H_nn_rfc5054(usr->hash_alg, usr->ng->N, usr->A, B); else u = H_nn_orig(usr->hash_alg, usr->A, B); if (!u) goto cleanup_and_exit; x = calculate_x( usr->hash_alg, s, usr->username, usr->password, usr->password_len ); if (!x) goto cleanup_and_exit; if (usr->rfc5054) k = H_nn_rfc5054(usr->hash_alg, usr->ng->N, usr->ng->N, usr->ng->g); else k = H_nn_orig(usr->hash_alg, usr->ng->N, usr->ng->g); if (!k) goto cleanup_and_exit; /* SRP-6a safety check */ if ( !BN_is_zero(B) && !BN_is_zero(u) ) { BN_mod_exp(v, usr->ng->g, x, usr->ng->N, ctx); /* S = (B - k*(g^x)) ^ (a + ux) */ BN_mul(tmp1, u, x, ctx); BN_add(tmp2, usr->a, tmp1); /* tmp2 = (a + ux) */ BN_mod_exp(tmp1, usr->ng->g, x, usr->ng->N, ctx); BN_mul(tmp3, k, tmp1, ctx); /* tmp3 = k*(g^x) */ BN_sub(tmp1, B, tmp3); /* tmp1 = (B - K*(g^x)) */ BN_mod_exp(usr->S, tmp1, tmp2, usr->ng->N, ctx); #ifdef APPLE_VARIANT hash_session_key(usr->hash_alg, usr->S, usr->session_key); #else hash_num(usr->hash_alg, usr->S, usr->session_key); #endif calculate_M( usr->hash_alg, usr->ng, usr->M, usr->username, s, usr->A, B, usr->session_key ); calculate_H_AMK( usr->hash_alg, usr->H_AMK, usr->A, usr->M, usr->session_key ); *bytes_M = usr->M; if (len_M) *len_M = hash_length( usr->hash_alg ); } else { *bytes_M = NULL; if (len_M) *len_M = 0; } cleanup_and_exit: BN_free(s); BN_free(B); BN_free(u); BN_free(x); BN_free(k); BN_free(v); BN_free(tmp1); BN_free(tmp2); BN_free(tmp3); BN_CTX_free(ctx); } void srp_user_verify_session( struct SRPUser * usr, const unsigned char * bytes_HAMK ) { if ( memcmp( usr->H_AMK, bytes_HAMK, hash_length(usr->hash_alg) ) == 0 ) usr->authenticated = 1; } #endif /*end removed section 4 */