From be65ae82130e6908c88b975597d05f128057a287 Mon Sep 17 00:00:00 2001 From: Dmitry Belyavskiy Date: Tue, 4 Sep 2018 16:10:01 +0300 Subject: [PATCH] GOST key transport 2018 - decrypt as separate function --- e_gost_err.c | 3 +- e_gost_err.h | 2 +- gost.txt | 3 ++ gost_ec_keyx.c | 110 +++++++++++++++++++++++++++++++++++++++-------- gost_keyexpimp.c | 8 +++- gost_lcl.h | 2 +- 6 files changed, 103 insertions(+), 25 deletions(-) diff --git a/e_gost_err.c b/e_gost_err.c index d3008d2..0bc0856 100644 --- a/e_gost_err.c +++ b/e_gost_err.c @@ -50,8 +50,7 @@ static ERR_STRING_DATA GOST_str_functs[] = { {ERR_PACK(0, GOST_F_PARAM_COPY_GOST_EC, 0), "param_copy_gost_ec"}, {ERR_PACK(0, GOST_F_PKEY_GOST2001_PARAMGEN, 0), "pkey_gost2001_paramgen"}, {ERR_PACK(0, GOST_F_PKEY_GOST2012_PARAMGEN, 0), "pkey_gost2012_paramgen"}, - {ERR_PACK(0, GOST_F_PKEY_GOST2018_ECCP_ENCRYPT, 0), - "pkey_gost2018_encrypt"}, + {ERR_PACK(0, GOST_F_PKEY_GOST2018_DECRYPT, 0), "pkey_gost2018_decrypt"}, {ERR_PACK(0, GOST_F_PKEY_GOST2018_ENCRYPT, 0), "pkey_gost2018_encrypt"}, {ERR_PACK(0, GOST_F_PKEY_GOST_CTRL, 0), "pkey_gost_ctrl"}, {ERR_PACK(0, GOST_F_PKEY_GOST_ECCP_DECRYPT, 0), "pkey_GOST_ECcp_decrypt"}, diff --git a/e_gost_err.h b/e_gost_err.h index 2b1d8ba..90c3b41 100644 --- a/e_gost_err.h +++ b/e_gost_err.h @@ -57,7 +57,7 @@ void ERR_GOST_error(int function, int reason, char *file, int line); # define GOST_F_PARAM_COPY_GOST_EC 119 # define GOST_F_PKEY_GOST2001_PARAMGEN 120 # define GOST_F_PKEY_GOST2012_PARAMGEN 121 -# define GOST_F_PKEY_GOST2018_ECCP_ENCRYPT 150 +# define GOST_F_PKEY_GOST2018_DECRYPT 150 # define GOST_F_PKEY_GOST2018_ENCRYPT 151 # define GOST_F_PKEY_GOST_CTRL 122 # define GOST_F_PKEY_GOST_ECCP_DECRYPT 123 diff --git a/gost.txt b/gost.txt index 3f3ffcd..540b755 100644 --- a/gost.txt +++ b/gost.txt @@ -37,6 +37,8 @@ GOST_F_OMAC_KEY:138:omac_key GOST_F_PARAM_COPY_GOST_EC:119:param_copy_gost_ec GOST_F_PKEY_GOST2001_PARAMGEN:120:pkey_gost2001_paramgen GOST_F_PKEY_GOST2012_PARAMGEN:121:pkey_gost2012_paramgen +GOST_F_PKEY_GOST2018_DECRYPT:150:pkey_gost2018_decrypt +GOST_F_PKEY_GOST2018_ENCRYPT:151:pkey_gost2018_encrypt GOST_F_PKEY_GOST_CTRL:122:pkey_gost_ctrl GOST_F_PKEY_GOST_ECCP_DECRYPT:123:pkey_GOST_ECcp_decrypt GOST_F_PKEY_GOST_ECCP_ENCRYPT:124:pkey_GOST_ECcp_encrypt @@ -67,6 +69,7 @@ GOST_R_BAD_PKEY_PARAMETERS_FORMAT:101:bad pkey parameters format GOST_R_CANNOT_PACK_EPHEMERAL_KEY:102:cannot pack ephemeral key GOST_R_CIPHER_NOT_FOUND:103:cipher not found GOST_R_CTRL_CALL_FAILED:104:ctrl call failed +GOST_R_ERROR_COMPUTING_EXPORT_KEYS:135:error computing export keys GOST_R_ERROR_COMPUTING_SHARED_KEY:105:error computing shared key GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO:106:error parsing key transport info GOST_R_ERROR_POINT_MUL:107:error point mul diff --git a/gost_ec_keyx.c b/gost_ec_keyx.c index 878698f..1e17f83 100644 --- a/gost_ec_keyx.c +++ b/gost_ec_keyx.c @@ -342,6 +342,10 @@ int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, return -1; } +/* + * EVP_PKEY_METHOD callback decrypt + * Implementation of GOST2018 key transport + */ int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, size_t *out_len, const unsigned char *key, size_t key_len) @@ -355,17 +359,19 @@ int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, int ret = 0; int mac_nid = NID_undef; size_t mac_len = 0; - int exp_len = 0; + int exp_len = 0, iv_len = 0; unsigned char *exp_buf = NULL; switch (data->cipher_nid) { case NID_magma_ctr: mac_nid = NID_magma_mac; mac_len = 8; + iv_len = 4; break; case NID_grasshopper_ctr: mac_nid = NID_grasshopper_mac; mac_len = 16; + iv_len = 8; break; default: GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_INVALID_CIPHER); @@ -379,30 +385,26 @@ int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, return -1; } - if (out) { - sec_key = EVP_PKEY_new(); - if (!EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new()) - || !EVP_PKEY_copy_parameters(sec_key, pubk) - || !gost_ec_keygen(EVP_PKEY_get0(sec_key))) { - GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, - GOST_R_ERROR_COMPUTING_SHARED_KEY); - goto err; - } + sec_key = EVP_PKEY_new(); + if (!EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new()) + || !EVP_PKEY_copy_parameters(sec_key, pubk) + || !gost_ec_keygen(EVP_PKEY_get0(sec_key))) { + GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, + GOST_R_ERROR_COMPUTING_SHARED_KEY); + goto err; } - ret = - gost_keg(data->shared_ukm, pkey_nid, + + if (gost_keg(data->shared_ukm, pkey_nid, EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)), - EVP_PKEY_get0(sec_key), expkeys); - if (ret <= 0) { + EVP_PKEY_get0(sec_key), expkeys) <= 0) { GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_ERROR_COMPUTING_EXPORT_KEYS); goto err; } - ret = gost_kexp15(key, key_len, data->cipher_nid, expkeys + 32, - mac_nid, expkeys + 0, data->shared_ukm + 24, 4, exp_buf, - &exp_len); - if (ret <= 0) { + if (gost_kexp15(key, key_len, data->cipher_nid, expkeys + 32, + mac_nid, expkeys + 0, data->shared_ukm + 24, iv_len, + exp_buf, &exp_len) <= 0) { GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_CANNOT_PACK_EPHEMERAL_KEY); goto err; } @@ -435,7 +437,7 @@ int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, /* * EVP_PKEY_METHOD callback decrypt - * Implementation of GOST2001 key transport, cryptopro variation + * Implementation of GOST2001/12 key transport, cryptopro variation */ int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key, size_t *key_len, const unsigned char *in, @@ -521,3 +523,73 @@ int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key, GOST_KEY_TRANSPORT_free(gkt); return ret; } + +/* + * EVP_PKEY_METHOD callback decrypt + * Implementation of GOST2018 key transport + */ +int pkey_gost2018_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key, + size_t *key_len, const unsigned char *in, + size_t in_len) +{ + const unsigned char *p = in; + struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx); + EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx); + PSKeyTransport_gost *pst = NULL; + int ret = 0; + unsigned char expkeys[64]; + EVP_PKEY *eph_key = NULL; + int pkey_nid = EVP_PKEY_base_id(eph_key); + int mac_nid = NID_undef; + int iv_len = 0; + + switch (data->cipher_nid) { + case NID_magma_ctr: + mac_nid = NID_magma_mac; + iv_len = 4; + break; + case NID_grasshopper_ctr: + mac_nid = NID_grasshopper_mac; + iv_len = 8; + break; + default: + GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_INVALID_CIPHER); + return -1; + break; + } + if (!key) { + *key_len = 32; + return 1; + } + + pst = d2i_PSKeyTransport_gost(NULL, (const unsigned char **)&p, in_len); + if (!pst) { + GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, + GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO); + return -1; + } + + eph_key = X509_PUBKEY_get(pst->ephem_key); + + if (gost_keg(data->shared_ukm, pkey_nid, + EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)), + EVP_PKEY_get0(priv), expkeys) <= 0) { + GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, + GOST_R_ERROR_COMPUTING_EXPORT_KEYS); + goto err; + } + + if (gost_kimp15(ASN1_STRING_get0_data(pst->psexp), + ASN1_STRING_length(pst->psexp), data->cipher_nid, + expkeys + 32, mac_nid, expkeys + 0, data->shared_ukm + 24, + iv_len, key) <= 0) { + GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_CANNOT_PACK_EPHEMERAL_KEY); + goto err; + } + + ret = 1; + err: + EVP_PKEY_free(eph_key); + PSKeyTransport_gost_free(pst); + return ret; +} diff --git a/gost_keyexpimp.c b/gost_keyexpimp.c index bfdefbc..5bd3b4a 100644 --- a/gost_keyexpimp.c +++ b/gost_keyexpimp.c @@ -82,14 +82,18 @@ int gost_kexp15(const unsigned char *shared_key, const int shared_len, return ret; } +/* + * Function expects that shared_key is a preallocated 32-bytes buffer + * */ int gost_kimp15(const unsigned char *expkey, const size_t expkeylen, int cipher_nid, const unsigned char *cipher_key, int mac_nid, unsigned char *mac_key, const unsigned char *iv, const size_t ivlen, - unsigned char *shared_key, size_t shared_len) + unsigned char *shared_key) { unsigned char iv_full[16], out[48], mac_buf[16]; unsigned int mac_len; + const size_t shared_len = 32; EVP_CIPHER_CTX *ciph = NULL; EVP_MD_CTX *mac = NULL; @@ -312,7 +316,7 @@ int main(void) ret = gost_kimp15(magma_export, 40, NID_magma_ctr, magma_key, - NID_magma_mac, mac_magma_key, magma_iv, 4, buf, 32); + NID_magma_mac, mac_magma_key, magma_iv, 4, buf); if (ret <= 0) ERR_print_errors_fp(stderr); diff --git a/gost_lcl.h b/gost_lcl.h index a6b6e12..9b0fa1c 100644 --- a/gost_lcl.h +++ b/gost_lcl.h @@ -282,7 +282,7 @@ int gost_kimp15(const unsigned char *expkey, const size_t expkeylen, int cipher_nid, const unsigned char *cipher_key, int mac_nid, unsigned char *mac_key, const unsigned char *iv, const size_t ivlen, - unsigned char *shared_key, size_t shared_len); + unsigned char *shared_key); /*============== miscellaneous functions============================= */ /* from gost_sign.c */ /* Convert GOST R 34.11 hash sum to bignum according to standard */ -- 2.39.2