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Diffstat (limited to 'srp/_srp.c')
| -rw-r--r-- | srp/_srp.c | 1568 |
1 files changed, 1568 insertions, 0 deletions
diff --git a/srp/_srp.c b/srp/_srp.c new file mode 100644 index 0000000..c2341d6 --- /dev/null +++ b/srp/_srp.c @@ -0,0 +1,1568 @@ +#include <Python.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> + +#include <openssl/bn.h> +#include <openssl/sha.h> +#include <openssl/crypto.h> +#include <openssl/rand.h> + +/*****************************************************************************/ +/* Begin SRP Header */ +/*****************************************************************************/ + +struct SRPVerifier; +struct SRPUser; + +typedef enum +{ + SRP_NG_1024, + SRP_NG_2048, + SRP_NG_4096, + SRP_NG_8192, + SRP_NG_CUSTOM +} SRP_NGType; + +typedef enum +{ + SRP_SHA1, + SRP_SHA224, + SRP_SHA256, + SRP_SHA384, + SRP_SHA512 +} SRP_HashAlgorithm; + + +/* This library will automatically seed the OpenSSL random number generator + * using cryptographically sound random data on Windows & Linux. If this is + * undesirable behavior or the host OS does not provide a /dev/urandom file, + * this function may be called to seed the random number generator with + * alternate data. + * + * Passing a null pointer to this function will cause this library to skip + * seeding the random number generator. + * + * Notes: + * * This function is optional on Windows & Linux. + * + * * This function is mandatory on all other platforms. Although it + * will appear to work on other platforms, this library uses the current + * time of day to seed the random number generator. This is well known to + * be insecure. + * + * * When using this function, ensure the provided random data is + * cryptographically strong. + */ +void srp_random_seed( const unsigned char * random_data, int data_length ); + + +/* Out: bytes_s, len_s, bytes_v, len_v + * + * The caller is responsible for freeing the memory allocated for bytes_s and bytes_v + * + * The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type. + * If provided, they must contain ASCII text of the hexidecimal notation. + */ +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 ); + + +/* Out: bytes_B, len_B. + * + * On failure, bytes_B will be set to NULL and len_B will be set to 0 + * + * The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type + */ +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, + const unsigned char ** bytes_B, int * len_B, + const char * n_hex, const char * g_hex ); + + +void srp_verifier_delete( struct SRPVerifier * ver ); + + +int srp_verifier_is_authenticated( struct SRPVerifier * ver ); + + +const char * srp_verifier_get_username( struct SRPVerifier * ver ); + +/* key_length may be null */ +const unsigned char * srp_verifier_get_session_key( struct SRPVerifier * ver, int * key_length ); + + +int srp_verifier_get_session_key_length( struct SRPVerifier * ver ); + + +/* user_M must be exactly srp_verifier_get_session_key_length() bytes in size */ +void srp_verifier_verify_session( struct SRPVerifier * ver, + const unsigned char * user_M, + const unsigned char ** bytes_HAMK ); + +/*******************************************************************************/ + +/* The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type */ +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 ); + +void srp_user_delete( struct SRPUser * usr ); + +int srp_user_is_authenticated( struct SRPUser * usr); + + +const char * srp_user_get_username( struct SRPUser * usr ); + +/* key_length may be null */ +const unsigned char * srp_user_get_session_key( struct SRPUser * usr, int * key_length ); + +int srp_user_get_session_key_length( struct SRPUser * usr ); + +/* 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 ); + +/* Output: bytes_M, len_M (len_M may be null and will always be + * srp_user_get_session_key_length() bytes in size) */ +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 ); + +/* bytes_HAMK must be exactly srp_user_get_session_key_length() bytes in size */ +void srp_user_verify_session( struct SRPUser * usr, const unsigned char * bytes_HAMK ); + + +/*****************************************************************************/ +/* Begin SRP Library */ +/*****************************************************************************/ + + +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[] = { + { /* 1024 */ + "EEAF0AB9ADB38DD69C33F80AFA8FC5E86072618775FF3C0B9EA2314C9C256576D674DF7496" + "EA81D3383B4813D692C6E0E0D5D8E250B98BE48E495C1D6089DAD15DC7D7B46154D6B6CE8E" + "F4AD69B15D4982559B297BCF1885C529F566660E57EC68EDBC3C05726CC02FD4CBF4976EAA" + "9AFD5138FE8376435B9FC61D2FC0EB06E3", + "2" + }, + { /* 2048 */ + "AC6BDB41324A9A9BF166DE5E1389582FAF72B6651987EE07FC3192943DB56050A37329CBB4" + "A099ED8193E0757767A13DD52312AB4B03310DCD7F48A9DA04FD50E8083969EDB767B0CF60" + "95179A163AB3661A05FBD5FAAAE82918A9962F0B93B855F97993EC975EEAA80D740ADBF4FF" + "747359D041D5C33EA71D281E446B14773BCA97B43A23FB801676BD207A436C6481F1D2B907" + "8717461A5B9D32E688F87748544523B524B0D57D5EA77A2775D2ECFA032CFBDBF52FB37861" + "60279004E57AE6AF874E7303CE53299CCC041C7BC308D82A5698F3A8D0C38271AE35F8E9DB" + "FBB694B5C803D89F7AE435DE236D525F54759B65E372FCD68EF20FA7111F9E4AFF73", + "2" + }, + { /* 4096 */ + "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08" + "8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B" + "302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9" + "A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6" + "49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8" + "FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D" + "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C" + "180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718" + "3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D" + "04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D" + "B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226" + "1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C" + "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC" + "E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26" + "99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB" + "04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2" + "233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127" + "D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934063199" + "FFFFFFFFFFFFFFFF", + "5" + }, + { /* 8192 */ + "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08" + "8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B" + "302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9" + "A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6" + "49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8" + "FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D" + "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C" + "180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718" + "3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D" + "04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D" + "B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226" + "1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C" + "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC" + "E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26" + "99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB" + "04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2" + "233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127" + "D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934028492" + "36C3FAB4D27C7026C1D4DCB2602646DEC9751E763DBA37BDF8FF9406" + "AD9E530EE5DB382F413001AEB06A53ED9027D831179727B0865A8918" + "DA3EDBEBCF9B14ED44CE6CBACED4BB1BDB7F1447E6CC254B33205151" + "2BD7AF426FB8F401378CD2BF5983CA01C64B92ECF032EA15D1721D03" + "F482D7CE6E74FEF6D55E702F46980C82B5A84031900B1C9E59E7C97F" + "BEC7E8F323A97A7E36CC88BE0F1D45B7FF585AC54BD407B22B4154AA" + "CC8F6D7EBF48E1D814CC5ED20F8037E0A79715EEF29BE32806A1D58B" + "B7C5DA76F550AA3D8A1FBFF0EB19CCB1A313D55CDA56C9EC2EF29632" + "387FE8D76E3C0468043E8F663F4860EE12BF2D5B0B7474D6E694F91E" + "6DBE115974A3926F12FEE5E438777CB6A932DF8CD8BEC4D073B931BA" + "3BC832B68D9DD300741FA7BF8AFC47ED2576F6936BA424663AAB639C" + "5AE4F5683423B4742BF1C978238F16CBE39D652DE3FDB8BEFC848AD9" + "22222E04A4037C0713EB57A81A23F0C73473FC646CEA306B4BCBC886" + "2F8385DDFA9D4B7FA2C087E879683303ED5BDD3A062B3CF5B3A278A6" + "6D2A13F83F44F82DDF310EE074AB6A364597E899A0255DC164F31CC5" + "0846851DF9AB48195DED7EA1B1D510BD7EE74D73FAF36BC31ECFA268" + "359046F4EB879F924009438B481C6CD7889A002ED5EE382BC9190DA6" + "FC026E479558E4475677E9AA9E3050E2765694DFC81F56E880B96E71" + "60C980DD98EDD3DFFFFFFFFFFFFFFFFF", + "13" + }, + {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_type != SRP_NG_CUSTOM ) + { + n_hex = global_Ng_constants[ ng_type ].n_hex; + g_hex = global_Ng_constants[ ng_type ].g_hex; + } + + BN_hex2bn( &ng->N, n_hex ); + BN_hex2bn( &ng->g, g_hex ); + + return ng; +} + +static void delete_ng( NGConstant * ng ) +{ + BN_free( ng->N ); + BN_free( ng->g ); + ng->N = 0; + ng->g = 0; + free(ng); +} + + + +typedef union +{ + SHA_CTX sha; + SHA256_CTX sha256; + SHA512_CTX sha512; +} HashCTX; + + +struct SRPVerifier +{ + SRP_HashAlgorithm hash_alg; + NGConstant *ng; + + const char * username; + const unsigned char * bytes_B; + int authenticated; + + unsigned char M [SHA512_DIGEST_LENGTH]; + unsigned char H_AMK [SHA512_DIGEST_LENGTH]; + unsigned char session_key [SHA512_DIGEST_LENGTH]; +}; + + +struct SRPUser +{ + SRP_HashAlgorithm hash_alg; + NGConstant *ng; + + BIGNUM *a; + BIGNUM *A; + BIGNUM *S; + + const unsigned char * bytes_A; + int authenticated; + + const char * username; + const unsigned char * password; + int password_len; + + unsigned char M [SHA512_DIGEST_LENGTH]; + unsigned char H_AMK [SHA512_DIGEST_LENGTH]; + unsigned char session_key [SHA512_DIGEST_LENGTH]; +}; + + +static int hash_init( SRP_HashAlgorithm alg, HashCTX *c ) +{ + switch (alg) + { + case SRP_SHA1 : return SHA1_Init( &c->sha ); + case SRP_SHA224: return SHA224_Init( &c->sha256 ); + case SRP_SHA256: return SHA256_Init( &c->sha256 ); + case SRP_SHA384: return SHA384_Init( &c->sha512 ); + case SRP_SHA512: return SHA512_Init( &c->sha512 ); + default: + return -1; + }; +} +static int hash_update( SRP_HashAlgorithm alg, HashCTX *c, const void *data, size_t len ) +{ + switch (alg) + { + case SRP_SHA1 : return SHA1_Update( &c->sha, data, len ); + case SRP_SHA224: return SHA224_Update( &c->sha256, data, len ); + case SRP_SHA256: return SHA256_Update( &c->sha256, data, len ); + case SRP_SHA384: return SHA384_Update( &c->sha512, data, len ); + case SRP_SHA512: return SHA512_Update( &c->sha512, data, len ); + default: + return -1; + }; +} +static int hash_final( SRP_HashAlgorithm alg, HashCTX *c, unsigned char *md ) +{ + switch (alg) + { + case SRP_SHA1 : return SHA1_Final( md, &c->sha ); + case SRP_SHA224: return SHA224_Final( md, &c->sha256 ); + case SRP_SHA256: return SHA256_Final( md, &c->sha256 ); + case SRP_SHA384: return SHA384_Final( md, &c->sha512 ); + case SRP_SHA512: return SHA512_Final( md, &c->sha512 ); + default: + return -1; + }; +} +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( 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 ); + 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_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 ); + 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]; + HashCTX ctx; + + 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 ); + + return H_ns( alg, salt, ucp_hash, hash_length(alg) ); +} + +static void update_hash_n( SRP_HashAlgorithm alg, HashCTX *ctx, const BIGNUM * n ) +{ + unsigned long len = BN_num_bytes(n); + unsigned char * n_bytes = (unsigned char *) malloc( len ); + 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 ); + BN_bn2bin(n, bin); + hash( alg, bin, nbytes, dest ); + free(bin); +} + +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 ]; + HashCTX 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]; + + 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 ); + hash_update( alg, &ctx, K, hash_len ); + + hash_final( alg, &ctx, dest ); +} + +static void calculate_H_AMK( SRP_HashAlgorithm alg, unsigned char *dest, const BIGNUM * A, const unsigned char * M, const unsigned char * K ) +{ + HashCTX ctx; + + hash_init( alg, &ctx ); + + update_hash_n( alg, &ctx, A ); + hash_update( alg, &ctx, M, hash_length(alg) ); + hash_update( alg, &ctx, K, hash_length(alg) ); + + hash_final( alg, &ctx, dest ); +} + +/* Python module calls random_seed during module initialization */ +#define init_random() + + +/*********************************************************************************************************** + * + * 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 ); + + init_random(); /* Only happens once */ + + BN_rand(s, 32, -1, 0); + + x = calculate_x( alg, s, username, password, len_password ); + + 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 ); + + BN_bn2bin(s, (unsigned char *) *bytes_s); + BN_bn2bin(v, (unsigned char *) *bytes_v); + + delete_ng( ng ); + BN_free(s); + BN_free(v); + BN_free(x); + BN_CTX_free(ctx); +} + + + +/* 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, + const unsigned char ** bytes_B, int * len_B, + const char * n_hex, const char * g_hex ) +{ + 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 = (struct SRPVerifier *) malloc( sizeof(struct SRPVerifier) ); + + init_random(); /* Only happens once */ + + ver->username = (char *) malloc( ulen ); + ver->hash_alg = alg; + ver->ng = ng; + + memcpy( (char*)ver->username, username, ulen ); + + ver->authenticated = 0; + + /* SRP-6a safety check */ + BN_mod(tmp1, A, ng->N, ctx); + if ( !BN_is_zero(tmp1) ) + { + BN_rand(b, 256, -1, 0); + + k = H_nn(alg, ng->N, ng->g); + + /* B = kv + g^b */ + BN_mul(tmp1, k, v, ctx); + BN_mod_exp(tmp2, ng->g, b, ng->N, ctx); + BN_add(B, tmp1, tmp2); + + u = H_nn(alg, A, B); + + /* 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); + + hash_num(alg, S, ver->session_key); + + 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 = malloc( *len_B ); + + BN_bn2bin( B, (unsigned char *) *bytes_B ); + + ver->bytes_B = *bytes_B; + } + else + { + *len_B = 0; + *bytes_B = NULL; + } + + 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 ) +{ + delete_ng( ver->ng ); + free( (char *) ver->username ); + free( (unsigned char *) ver->bytes_B ); + 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) + *key_length = hash_length( ver->hash_alg ); + return ver->session_key; +} + + +int srp_verifier_get_session_key_length( struct SRPVerifier * ver ) +{ + return hash_length( ver->hash_alg ); +} + + +/* 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; +} + +/*******************************************************************************/ + +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 ) +{ + struct SRPUser *usr = (struct SRPUser *) malloc( sizeof(struct SRPUser) ); + int ulen = strlen(username) + 1; + + 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(); + + usr->username = (const char *) malloc(ulen); + usr->password = (const unsigned char *) malloc(len_password); + usr->password_len = len_password; + + memcpy((char *)usr->username, username, ulen); + memcpy((char *)usr->password, bytes_password, len_password); + + usr->authenticated = 0; + + usr->bytes_A = 0; + + return usr; +} + + + +void srp_user_delete( struct SRPUser * usr ) +{ + BN_free( usr->a ); + BN_free( usr->A ); + BN_free( usr->S ); + + delete_ng( usr->ng ); + + free((char *)usr->username); + free((char *)usr->password); + + if (usr->bytes_A) + free( (char *)usr->bytes_A ); + + 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) + *key_length = hash_length( usr->hash_alg ); + return usr->session_key; +} + + +int srp_user_get_session_key_length( struct SRPUser * usr ) +{ + return hash_length( usr->hash_alg ); +} + + + +/* 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 = malloc( *len_A ); + + 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(); + + u = H_nn(usr->hash_alg, usr->A, B); + + x = calculate_x( usr->hash_alg, s, usr->username, usr->password, usr->password_len ); + + k = H_nn(usr->hash_alg, usr->ng->N, usr->ng->g); + + /* 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); + + hash_num(usr->hash_alg, usr->S, usr->session_key); + + 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; + } + + 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; +} + + +/****************************************************************************** + * + * Python Module + * + *****************************************************************************/ + +typedef struct +{ + PyObject_HEAD + struct SRPVerifier * ver; + const unsigned char * bytes_B; + const unsigned char * bytes_s; + int len_B; + int len_s; +}PyVerifier; + + +typedef struct +{ + PyObject_HEAD + struct SRPUser * usr; +}PyUser; + + +static void ver_dealloc( PyVerifier * self ) +{ + if ( self->ver != NULL ) + srp_verifier_delete( self->ver ); + + if ( self->bytes_s != NULL ) + free( (char *)self->bytes_s ); + + self->ob_type->tp_free( (PyObject *) self ); +} + + +static void usr_dealloc( PyUser * self ) +{ + if ( self->usr != NULL ) + srp_user_delete( self->usr ); + self->ob_type->tp_free( (PyObject *) self ); +} + + +static PyObject * ver_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + PyVerifier *self = (PyVerifier *) type->tp_alloc(type, 0); + + if (!self) + return NULL; + + self->ver = NULL; + self->bytes_B = NULL; + self->bytes_s = NULL; + self->len_B = 0; + self->len_s = 0; + + return (PyObject *) self; +} + + +static PyObject * usr_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + PyUser *self = (PyUser *) type->tp_alloc(type, 0); + + if (!self) + return NULL; + + self->usr = NULL; + + return (PyObject *) self; +} + + +static int ver_init( PyVerifier *self, PyObject *args, PyObject *kwds ) +{ + const char *username; + const unsigned char *bytes_s, *bytes_v, *bytes_A; + int len_s, len_v, len_A; + int hash_alg = SRP_SHA1; + int ng_type = SRP_NG_2048; + const char *n_hex = 0; + const char *g_hex = 0; + static char * kwnames[] = { "username", "bytes_s", "bytes_v", "bytes_A", + "hash_alg", "ng_type", + "n_hex", "g_hex", NULL }; + + if ( self->ver != NULL ) + { + PyErr_SetString(PyExc_TypeError, "Type cannot be re-initialized"); + return -1; + } + + if ( ! PyArg_ParseTupleAndKeywords(args, kwds, "st#t#t#|iiss", kwnames, + &username, + &bytes_s, &len_s, + &bytes_v, &len_v, + &bytes_A, &len_A, + &hash_alg, + &ng_type, + &n_hex, + &g_hex ) ) + { + return -1; + } + + if ( hash_alg < SRP_SHA1 || hash_alg > SRP_SHA512 ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Hash Algorithm"); + return -1; + } + + if ( ng_type < SRP_NG_1024 || ng_type > SRP_NG_CUSTOM ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Prime Number Constant"); + return -1; + } + + if ( ng_type == SRP_NG_CUSTOM && ( !n_hex || !g_hex ) ) + { + PyErr_SetString(PyExc_ValueError, "Both n_hex and g_hex are required when ng_type = NG_CUSTOM"); + return -1; + } + + /* The srp_verifier_new command is computationally intensive. Allowing multiple, + * simultaneous calls here will speed things up for multi-cpu machines + */ + Py_BEGIN_ALLOW_THREADS + self->ver = srp_verifier_new( (SRP_HashAlgorithm) hash_alg, + (SRP_NGType) ng_type, + username, + bytes_s, len_s, + bytes_v, len_v, + bytes_A, len_A, + &self->bytes_B, &self->len_B, + n_hex, + g_hex ); + Py_END_ALLOW_THREADS + + if ( self->bytes_B == NULL ) + { + PyErr_SetString(PyExc_Exception, "SRP-6a safety check violated"); + return -1; + } + + self->bytes_s = malloc( len_s ); + self->len_s = len_s; + + memcpy( (char *)self->bytes_s, bytes_s, len_s ); + + return 0; +} + + +static int usr_init( PyUser *self, PyObject *args, PyObject *kwds ) +{ + const char *username = 0; + const unsigned char *bytes_password = 0; + int len_password = 0; + int hash_alg = SRP_SHA1; + int ng_type = SRP_NG_2048; + const char *n_hex = 0; + const char *g_hex = 0; + static char * kwnames[] = { "username", "password", "hash_alg", + "ng_type", "n_hex", "g_hex", NULL }; + + + if ( self->usr != NULL ) + { + PyErr_SetString(PyExc_TypeError, "Type cannot be re-initialized"); + return -1; + } + + if ( ! PyArg_ParseTupleAndKeywords(args, kwds, "st#|iiss", kwnames, + &username, + &bytes_password, + &len_password, + &hash_alg, + &ng_type, + &n_hex, + &g_hex) ) + { + return -1; + } + + if ( hash_alg < SRP_SHA1 || hash_alg > SRP_SHA512 ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Hash Algorithm"); + return -1; + } + + if ( ng_type < SRP_NG_1024 || ng_type > SRP_NG_CUSTOM ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Prime Number Constant"); + return -1; + } + + if ( ng_type == SRP_NG_CUSTOM && ( !n_hex || !g_hex ) ) + { + PyErr_SetString(PyExc_ValueError, "Both n_hex and g_hex are required when ng_type = NG_CUSTOM"); + return -1; + } + + + self->usr = srp_user_new( (SRP_HashAlgorithm) hash_alg, + (SRP_NGType) ng_type, + username, + bytes_password, + len_password, + n_hex, + g_hex ); + + return 0; +} + + +static PyObject * ver_is_authenticated( PyVerifier * self ) +{ + if ( self->ver == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + if ( srp_verifier_is_authenticated(self->ver) ) + Py_RETURN_TRUE; + else + Py_RETURN_FALSE; +} + + +static PyObject * usr_is_authenticated( PyUser * self ) +{ + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + if ( srp_user_is_authenticated(self->usr) ) + Py_RETURN_TRUE; + else + Py_RETURN_FALSE; +} + + +static PyObject * ver_get_username( PyVerifier * self ) +{ + if ( self->ver == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + return PyString_FromString( srp_verifier_get_username(self->ver) ); +} + + +static PyObject * usr_get_username( PyUser * self ) +{ + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + return PyString_FromString( srp_user_get_username(self->usr) ); +} + + +static PyObject * ver_get_session_key( PyVerifier * self ) +{ + if ( self->ver == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + if ( srp_verifier_is_authenticated(self->ver) ) + { + int key_len; + const char * u = (const char *)srp_verifier_get_session_key(self->ver, &key_len); + return PyString_FromStringAndSize(u, key_len); + } + else + Py_RETURN_NONE; +} + + +static PyObject * usr_get_session_key( PyUser * self ) +{ + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + if ( srp_user_is_authenticated(self->usr) ) + { + int key_len; + const char * u = (const char *) srp_user_get_session_key(self->usr, &key_len); + return PyString_FromStringAndSize(u, key_len); + } + else + Py_RETURN_NONE; +} + + +static PyObject * ver_get_challenge( PyVerifier * self ) +{ + if ( self->ver == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + if ( self->bytes_B == NULL ) { + PyErr_SetString(PyExc_Exception, "SRP-6a security check failed"); + return NULL; + } + + return Py_BuildValue("s#s#", self->bytes_s, + self->len_s, + self->bytes_B, + self->len_B); +} + + +static PyObject * ver_verify_session( PyVerifier * self, PyObject * args ) +{ + const unsigned char * bytes_M; + const unsigned char * bytes_HAMK; + int len_M; + + if ( self->ver == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + if ( ! PyArg_ParseTuple(args, "t#", &bytes_M, &len_M) ) + { + return NULL; + } + + if ( len_M != srp_verifier_get_session_key_length( self->ver ) ) + Py_RETURN_NONE; + + srp_verifier_verify_session( self->ver, bytes_M, &bytes_HAMK ); + + if ( bytes_HAMK == NULL ) + Py_RETURN_NONE; + else + return PyString_FromStringAndSize((const char *) bytes_HAMK, + srp_verifier_get_session_key_length( self->ver )); +} + + +static PyObject * usr_start_authentication( PyUser * self ) +{ + const char * username; + const unsigned char * bytes_A; + int len_A; + + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + srp_user_start_authentication( self->usr, &username, &bytes_A, &len_A ); + + return Py_BuildValue("ss#", username, bytes_A, len_A); +} + + +static PyObject * usr_process_challenge( PyUser * self, PyObject * args ) +{ + const unsigned char * bytes_s, *bytes_B; + int len_s, len_B, len_M; + const unsigned char * bytes_M; + + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + if ( ! PyArg_ParseTuple(args, "t#t#", &bytes_s, &len_s, &bytes_B, + &len_B) ) + { + return NULL; + } + + /* The srp_user_process_challenge command is computationally intensive. + * Allowing multiple, simultaneous calls here will speed things up on + * multi-cpu machines. + */ + Py_BEGIN_ALLOW_THREADS + srp_user_process_challenge( self->usr, bytes_s, len_s, bytes_B, len_B, + &bytes_M, &len_M ); + Py_END_ALLOW_THREADS + + if (bytes_M == NULL) + Py_RETURN_NONE; + else + return PyString_FromStringAndSize((const char *) bytes_M, len_M); +} + + +static PyObject * usr_verify_session( PyUser * self, PyObject * args ) +{ + const unsigned char * bytes_HAMK; + int len_HAMK; + + if ( self->usr == NULL ) { + PyErr_SetString(PyExc_Exception, "Type not initialized"); + return NULL; + } + + if ( ! PyArg_ParseTuple(args, "t#", &bytes_HAMK, &len_HAMK) ) + { + return NULL; + } + + if ( len_HAMK == srp_user_get_session_key_length( self->usr ) ) + srp_user_verify_session( self->usr, bytes_HAMK ); + + Py_RETURN_NONE; +} + + +static PyObject * py_create_salted_verification_key( PyObject *self, PyObject *args, PyObject *kwds ) +{ + PyObject *ret; + const char *username; + const unsigned char *bytes_password, *bytes_s, *bytes_v; + int len_password, len_s, len_v; + int hash_alg = SRP_SHA1; + int ng_type = SRP_NG_2048; + const char *n_hex = 0; + const char *g_hex = 0; + static char * kwnames[] = { "username", "password", "hash_alg", + "ng_type", "n_hex", "g_hex", NULL }; + + if ( ! PyArg_ParseTupleAndKeywords(args, kwds, "st#|iiss", kwnames, + &username, + &bytes_password, + &len_password, + &hash_alg, + &ng_type, + &n_hex, + &g_hex) ) + return NULL; + + + if ( hash_alg < SRP_SHA1 || hash_alg > SRP_SHA512 ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Hash Algorithm"); + return NULL; + } + + if ( ng_type < SRP_NG_1024 || ng_type > SRP_NG_CUSTOM ) + { + PyErr_SetString(PyExc_ValueError, "Invalid Prime Number Constant"); + return NULL; + } + + if ( ng_type == SRP_NG_CUSTOM && ( !n_hex || !g_hex ) ) + { + PyErr_SetString(PyExc_ValueError, "Both n_hex and g_hex are required when ng_type = NG_CUSTOM"); + return NULL; + } + + srp_create_salted_verification_key( (SRP_HashAlgorithm) hash_alg, + (SRP_NGType) ng_type, + username, bytes_password, len_password, &bytes_s, &len_s, + &bytes_v, &len_v, + n_hex, + g_hex ); + + ret = Py_BuildValue("s#s#", bytes_s, len_s, bytes_v, len_v); + + free((char*)bytes_s); + free((char*)bytes_v); + + return ret; +} + + +/***********************************************************************************/ +static PyMethodDef PyVerifier_methods[] = { + {"authenticated", (PyCFunction) ver_is_authenticated, METH_NOARGS, + PyDoc_STR("Returns boolean indicating whether the session is " + "authenticated or not") + }, + {"get_username", (PyCFunction) ver_get_username, METH_NOARGS, + PyDoc_STR("Returns the username the Verifier instance is bound to.") + }, + {"get_session_key", (PyCFunction) ver_get_session_key, METH_NOARGS, + PyDoc_STR("Returns the session key for an authenticated session. " + "Returns None if the session is not authenticated.") + }, + {"get_challenge", (PyCFunction) ver_get_challenge, METH_NOARGS, + PyDoc_STR("Returns: (s,B) or None. The salt & challenge that " + "should be sent to the user or None if the SRP-6a " + "safety check fails.") + }, + {"verify_session", (PyCFunction) ver_verify_session, METH_VARARGS, + PyDoc_STR("Verifies the user based on their reply to " + "the challenge") + }, + {NULL} /* Sentinel */ +}; + + +static PyMethodDef PyUser_methods[] = { + {"authenticated", (PyCFunction) usr_is_authenticated, METH_NOARGS, + PyDoc_STR("Returns boolean indicating whether the session is " + "authenticated or not") + }, + {"get_username", (PyCFunction) usr_get_username, METH_NOARGS, + PyDoc_STR("Returns the username the User instance is bound to.") + }, + {"get_session_key", (PyCFunction) usr_get_session_key, METH_NOARGS, + PyDoc_STR("Returns the session key for an authenticated session. " + "Returns None if the session is not authenticated.") + }, + {"start_authentication", (PyCFunction) usr_start_authentication, + METH_NOARGS, + PyDoc_STR("Returns (username,A). The username and initial " + "authentication challenge to send to the verifier") + }, + {"process_challenge", (PyCFunction) usr_process_challenge, METH_VARARGS, + PyDoc_STR("Returns the reply to send to the server or None if the " + "SRP-6a safety check fails") + }, + {"verify_session", (PyCFunction) usr_verify_session, METH_VARARGS, + PyDoc_STR("Verifies the server based on its reply to the users " + "challenge response") + }, + {NULL} /* Sentinel */ +}; + + +static PyMethodDef srp_module_methods[] = { + {"create_salted_verification_key", (PyCFunction) py_create_salted_verification_key, METH_VARARGS | METH_KEYWORDS, + PyDoc_STR("Returns (s,v): Generates a salt & verifier for the " + "given username and password") + }, + {NULL} /* Sentinel */ +}; + + +static PyTypeObject PyVerifier_Type = { + PyVarObject_HEAD_INIT(NULL, 0) + "srp._srp.Verifier", /*tp_name*/ + sizeof(PyVerifier), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + /* methods */ + (destructor)ver_dealloc, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash*/ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT, /*tp_flags*/ + "SRP-6a verfier", /*tp_doc*/ + 0, /*tp_traverse*/ + 0, /*tp_clear*/ + 0, /*tp_richcompare*/ + 0, /*tp_weaklistoffset*/ + 0, /*tp_iter*/ + 0, /*tp_iternext*/ + PyVerifier_methods, /*tp_methods*/ + 0, /*tp_members*/ + 0, /*tp_getset*/ + 0, /*tp_base*/ + 0, /*tp_dict*/ + 0, /*tp_descr_get*/ + 0, /*tp_descr_set*/ + 0, /*tp_dictoffset*/ + (initproc)ver_init, /*tp_init*/ + 0, /*tp_alloc*/ + ver_new, /*tp_new*/ + 0, /*tp_free*/ + 0, /*tp_is_gc*/ +}; + + +static PyTypeObject PyUser_Type = { + PyVarObject_HEAD_INIT(NULL, 0) + "srp._srp.User", /*tp_name*/ + sizeof(PyUser), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + /* methods */ + (destructor)usr_dealloc, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash*/ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT, /*tp_flags*/ + "SRP-6a User", /*tp_doc*/ + 0, /*tp_traverse*/ + 0, /*tp_clear*/ + 0, /*tp_richcompare*/ + 0, /*tp_weaklistoffset*/ + 0, /*tp_iter*/ + 0, /*tp_iternext*/ + PyUser_methods, /*tp_methods*/ + 0, /*tp_members*/ + 0, /*tp_getset*/ + 0, /*tp_base*/ + 0, /*tp_dict*/ + 0, /*tp_descr_get*/ + 0, /*tp_descr_set*/ + 0, /*tp_dictoffset*/ + (initproc)usr_init, /*tp_init*/ + 0, /*tp_alloc*/ + usr_new, /*tp_new*/ + 0, /*tp_free*/ + 0, /*tp_is_gc*/ +}; + + +PyMODINIT_FUNC +init_srp(void) +{ + int init_ok = 0; + PyObject *m = NULL; + PyObject *os = NULL; + PyObject *py_urandom = NULL; + + os = PyImport_ImportModule("os"); + + if (os == NULL) + return; + + py_urandom = PyObject_GetAttrString(os, "urandom"); + + if ( py_urandom && PyCallable_Check(py_urandom) ) + { + PyObject *args = Py_BuildValue("(i)", 32); + if ( args ) + { + PyObject *randstr = PyObject_CallObject(py_urandom, args); + if ( randstr && PyString_Check(randstr)) + { + char *buff = NULL; + Py_ssize_t slen = 0; + if (!PyString_AsStringAndSize(randstr, &buff, &slen)) + { + srp_random_seed( (const unsigned char *)buff, slen ); + init_ok = 1; + } + } + Py_XDECREF(randstr); + } + Py_XDECREF(args); + } + + Py_XDECREF(os); + Py_XDECREF(py_urandom); + + if (!init_ok) + { + PyErr_SetString(PyExc_ImportError, "Initialization failed"); + return; + } + + + if (PyType_Ready(&PyVerifier_Type) < 0 || PyType_Ready(&PyUser_Type) < 0) + return; + + m = Py_InitModule3("srp._srp", srp_module_methods,"SRP-6a implementation"); + + if (m == NULL) + return; + + Py_INCREF(&PyVerifier_Type); + Py_INCREF(&PyUser_Type); + + PyModule_AddObject(m, "Verifier", (PyObject*) &PyVerifier_Type ); + PyModule_AddObject(m, "User", (PyObject*) &PyUser_Type ); + + PyModule_AddIntConstant(m, "NG_1024", SRP_NG_1024); + PyModule_AddIntConstant(m, "NG_2048", SRP_NG_2048); + PyModule_AddIntConstant(m, "NG_4096", SRP_NG_4096); + PyModule_AddIntConstant(m, "NG_8192", SRP_NG_8192); + PyModule_AddIntConstant(m, "NG_CUSTOM", SRP_NG_CUSTOM); + + + PyModule_AddIntConstant(m, "SHA1", SRP_SHA1); + PyModule_AddIntConstant(m, "SHA224", SRP_SHA224); + PyModule_AddIntConstant(m, "SHA256", SRP_SHA256); + PyModule_AddIntConstant(m, "SHA384", SRP_SHA384); + PyModule_AddIntConstant(m, "SHA512", SRP_SHA512); + +} |