diff options
Diffstat (limited to 'gost_ec_keyx.c')
| -rw-r--r-- | gost_ec_keyx.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/gost_ec_keyx.c b/gost_ec_keyx.c new file mode 100644 index 0000000..7a80d23 --- /dev/null +++ b/gost_ec_keyx.c @@ -0,0 +1,337 @@ +/********************************************************************** + * gost_ec_keyx.c * + * Copyright (c) 2005-2013 Cryptocom LTD * + * This file is distributed under the same license as OpenSSL * + * * + * VK0 34.10-2001 key exchange and GOST R 34.10-2001 * + * based PKCS7/SMIME support * + * Requires OpenSSL 0.9.9 for compilation * + **********************************************************************/ +#include <openssl/evp.h> +#include <openssl/rand.h> +#include <string.h> +#include <openssl/objects.h> +#include "gost89.h" +#include "e_gost_err.h" +#include "gost_keywrap.h" +#include "gost_lcl.h" + +/* Implementation of CryptoPro VKO 34.10-2001/2012 algorithm */ +static int VKO_compute_key(unsigned char *shared_key, size_t shared_key_size, + const EC_POINT *pub_key, EC_KEY *priv_key, + const unsigned char *ukm, int dgst_nid) +{ + unsigned char *databuf = NULL, *hashbuf = NULL; + BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL; + const BIGNUM *key = EC_KEY_get0_private_key(priv_key); + EC_POINT *pnt = EC_POINT_new(EC_KEY_get0_group(priv_key)); + int i; + BN_CTX *ctx = BN_CTX_new(); + EVP_MD_CTX mdctx; + const EVP_MD *md; + int effective_dgst_nid = (dgst_nid == NID_id_GostR3411_2012_512) ? + NID_id_GostR3411_2012_256 : dgst_nid; + int buf_len = (dgst_nid == NID_id_GostR3411_2012_512) ? 128 : 64, + half_len = buf_len >> 1; + + if (!ctx) { + GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_NO_MEMORY); + return 0; + } + BN_CTX_start(ctx); + + databuf = OPENSSL_malloc(buf_len); + hashbuf = OPENSSL_malloc(buf_len); + if (!databuf || !hashbuf) { + GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_MALLOC_FAILURE); + goto err; + } + + md = EVP_get_digestbynid(effective_dgst_nid); + if (!md) { + GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_INVALID_DIGEST_TYPE); + goto err; + } + + UKM = hashsum2bn(ukm, 8); + p = BN_CTX_get(ctx); + order = BN_CTX_get(ctx); + X = BN_CTX_get(ctx); + Y = BN_CTX_get(ctx); + EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx); + BN_mod_mul(p, key, UKM, order, ctx); + EC_POINT_mul(EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx); + EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(priv_key), + pnt, X, Y, ctx); + /* + * Serialize elliptic curve point same way as we do it when saving key + */ + store_bignum(Y, databuf, half_len); + store_bignum(X, databuf + half_len, half_len); + /* And reverse byte order of whole buffer */ + for (i = 0; i < buf_len; i++) { + hashbuf[buf_len - 1 - i] = databuf[i]; + } + EVP_MD_CTX_init(&mdctx); + EVP_DigestInit_ex(&mdctx, md, NULL); + EVP_DigestUpdate(&mdctx, hashbuf, buf_len); + EVP_DigestFinal_ex(&mdctx, shared_key, NULL); + EVP_MD_CTX_cleanup(&mdctx); + err: + BN_free(UKM); + BN_CTX_end(ctx); + BN_CTX_free(ctx); + EC_POINT_free(pnt); + if (databuf) + OPENSSL_free(databuf); + if (hashbuf) + OPENSSL_free(hashbuf); + + return 32; +} + +/* + * EVP_PKEY_METHOD callback derive. + * Implements VKO R 34.10-2001/2012 algorithms + */ +int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen) +{ + /* + * Public key of peer in the ctx field peerkey + * Our private key in the ctx pkey + * ukm is in the algorithm specific context data + */ + EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx); + EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx); + struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx); + int dgst_nid = NID_undef; + + if (!data || !data->shared_ukm) { + GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET); + return 0; + } + + if (key == NULL) { + *keylen = 32; + return 32; + } + + EVP_PKEY_get_default_digest_nid(my_key, &dgst_nid); + + *keylen = + VKO_compute_key(key, 32, + EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)), + (EC_KEY *)EVP_PKEY_get0(my_key), data->shared_ukm, + dgst_nid); + return (*keylen) ? 1 : 0; +} + +/* + * EVP_PKEY_METHOD callback encrypt + * Implementation of GOST2001 key transport, cryptocom variation + */ +/* + * Generates ephemeral key based on pubk algorithm computes shared key using + * VKO and returns filled up GOST_KEY_TRANSPORT structure + */ + +/* + * EVP_PKEY_METHOD callback encrypt + * Implementation of GOST2001 key transport, cryptopo variation + */ + +int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, + size_t *out_len, const unsigned char *key, + size_t key_len) +{ + GOST_KEY_TRANSPORT *gkt = NULL; + EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx); + struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx); + int pkey_nid = EVP_PKEY_base_id(pubk); + ASN1_OBJECT *crypt_params_obj = (pkey_nid == NID_id_GostR3410_2001) ? + OBJ_nid2obj(NID_id_Gost28147_89_CryptoPro_A_ParamSet) : + OBJ_nid2obj(NID_id_tc26_gost_28147_param_Z); + const struct gost_cipher_info *param = + get_encryption_params(crypt_params_obj); + unsigned char ukm[8], shared_key[32], crypted_key[44]; + int ret = 0; + int key_is_ephemeral = 1; + gost_ctx cctx; + EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx); + if (data->shared_ukm) { + memcpy(ukm, data->shared_ukm, 8); + } else if (out) { + + if (RAND_bytes(ukm, 8) <= 0) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, + GOST_R_RANDOM_GENERATOR_FAILURE); + return 0; + } + } + /* Check for private key in the peer_key of context */ + if (sec_key) { + key_is_ephemeral = 0; + if (!gost_get0_priv_key(sec_key)) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, + GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR); + goto err; + } + } else { + key_is_ephemeral = 1; + if (out) { + sec_key = EVP_PKEY_new(); + EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new()); + EVP_PKEY_copy_parameters(sec_key, pubk); + if (!gost_ec_keygen(EVP_PKEY_get0(sec_key))) { + goto err; + } + } + } + if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS) + && param == gost_cipher_list) { + param = gost_cipher_list + 1; + } + if (out) { + int dgst_nid = NID_undef; + EVP_PKEY_get_default_digest_nid(pubk, &dgst_nid); + + if (!VKO_compute_key(shared_key, 32, + EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)), + EVP_PKEY_get0(sec_key), ukm, dgst_nid)) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, + GOST_R_ERROR_COMPUTING_SHARED_KEY); + goto err; + } + gost_init(&cctx, param->sblock); + keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key); + } + gkt = GOST_KEY_TRANSPORT_new(); + if (!gkt) { + goto err; + } + if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) { + goto err; + } + if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) { + goto err; + } + if (!ASN1_OCTET_STRING_set + (gkt->key_info->encrypted_key, crypted_key + 8, 32)) { + goto err; + } + if (key_is_ephemeral) { + if (!X509_PUBKEY_set + (&gkt->key_agreement_info->ephem_key, out ? sec_key : pubk)) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, + GOST_R_CANNOT_PACK_EPHEMERAL_KEY); + goto err; + } + } + ASN1_OBJECT_free(gkt->key_agreement_info->cipher); + gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid); + if (key_is_ephemeral) + EVP_PKEY_free(sec_key); + if (!key_is_ephemeral) { + /* Set control "public key from client certificate used" */ + if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) + <= 0) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_CTRL_CALL_FAILED); + goto err; + } + } + if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL)) > 0) + ret = 1; + GOST_KEY_TRANSPORT_free(gkt); + return ret; + err: + if (key_is_ephemeral) + EVP_PKEY_free(sec_key); + GOST_KEY_TRANSPORT_free(gkt); + return -1; +} + +/* + * EVP_PKEY_METHOD callback decrypt + * Implementation of GOST2001 key transport, cryptopo variation + */ +int pkey_GOST_ECcp_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; + EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx); + GOST_KEY_TRANSPORT *gkt = NULL; + int ret = 0; + unsigned char wrappedKey[44]; + unsigned char sharedKey[32]; + gost_ctx ctx; + const struct gost_cipher_info *param = NULL; + EVP_PKEY *eph_key = NULL, *peerkey = NULL; + int dgst_nid = NID_undef; + + if (!key) { + *key_len = 32; + return 1; + } + gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len); + if (!gkt) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, + GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO); + return -1; + } + + /* If key transport structure contains public key, use it */ + eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key); + if (eph_key) { + if (EVP_PKEY_derive_set_peer(pctx, eph_key) <= 0) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, + GOST_R_INCOMPATIBLE_PEER_KEY); + goto err; + } + } else { + /* Set control "public key from client certificate used" */ + if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) + <= 0) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_CTRL_CALL_FAILED); + goto err; + } + } + peerkey = EVP_PKEY_CTX_get0_peerkey(pctx); + if (!peerkey) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_NO_PEER_KEY); + goto err; + } + + param = get_encryption_params(gkt->key_agreement_info->cipher); + if (!param) { + goto err; + } + + gost_init(&ctx, param->sblock); + OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8); + memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8); + OPENSSL_assert(gkt->key_info->encrypted_key->length == 32); + memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32); + OPENSSL_assert(gkt->key_info->imit->length == 4); + memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4); + + EVP_PKEY_get_default_digest_nid(priv, &dgst_nid); + if (!VKO_compute_key(sharedKey, 32, + EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)), + EVP_PKEY_get0(priv), wrappedKey, dgst_nid)) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, + GOST_R_ERROR_COMPUTING_SHARED_KEY); + goto err; + } + if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) { + GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, + GOST_R_ERROR_COMPUTING_SHARED_KEY); + goto err; + } + + ret = 1; + err: + EVP_PKEY_free(eph_key); + GOST_KEY_TRANSPORT_free(gkt); + return ret; +} |