| /********************************************************************** |
| * gost_keyx.c * |
| * Copyright (c) 2005-2006 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 "gosthash.h" |
| #include "e_gost_err.h" |
| #include "gost_keywrap.h" |
| #include "gost_lcl.h" |
| #include "gost2001_keyx.h" |
| |
| /* Implementation of CryptoPro VKO 34.10-2001 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) |
| { |
| unsigned char ukm_be[8], databuf[64], hashbuf[64]; |
| 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; |
| gost_hash_ctx hash_ctx; |
| BN_CTX *ctx = BN_CTX_new(); |
| |
| for (i = 0; i < 8; i++) { |
| ukm_be[7 - i] = ukm[i]; |
| } |
| BN_CTX_start(ctx); |
| UKM = getbnfrombuf(ukm_be, 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, 32); |
| store_bignum(X, databuf + 32, 32); |
| /* And reverse byte order of whole buffer */ |
| for (i = 0; i < 64; i++) { |
| hashbuf[63 - i] = databuf[i]; |
| } |
| init_gost_hash_ctx(&hash_ctx, &GostR3411_94_CryptoProParamSet); |
| start_hash(&hash_ctx); |
| hash_block(&hash_ctx, hashbuf, 64); |
| finish_hash(&hash_ctx, shared_key); |
| done_gost_hash_ctx(&hash_ctx); |
| BN_free(UKM); |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| EC_POINT_free(pnt); |
| return 32; |
| } |
| |
| /* |
| * EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-2001 |
| * algorithm |
| */ |
| int pkey_gost2001_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); |
| |
| if (!data->shared_ukm) { |
| GOSTerr(GOST_F_PKEY_GOST2001_DERIVE, GOST_R_UKM_NOT_SET); |
| return 0; |
| } |
| |
| if (key == NULL) { |
| *keylen = 32; |
| return 32; |
| } |
| |
| *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); |
| return 1; |
| } |
| |
| /* |
| * 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_GOST01cp_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); |
| const struct gost_cipher_info *param = get_encryption_params(NULL); |
| 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_GOST01CP_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_GOST01CP_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 (!gost2001_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) { |
| VKO_compute_key(shared_key, 32, |
| EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)), |
| EVP_PKEY_get0(sec_key), ukm); |
| 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_GOST01CP_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 && sec_key) |
| 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_GOST01CP_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 && sec_key) |
| 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_GOST01cp_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; |
| |
| 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_GOST01CP_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_GOST01CP_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_GOST01CP_DECRYPT, GOST_R_CTRL_CALL_FAILED); |
| goto err; |
| } |
| } |
| peerkey = EVP_PKEY_CTX_get0_peerkey(pctx); |
| if (!peerkey) { |
| GOSTerr(GOST_F_PKEY_GOST01CP_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); |
| VKO_compute_key(sharedKey, 32, |
| EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)), |
| EVP_PKEY_get0(priv), wrappedKey); |
| if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) { |
| GOSTerr(GOST_F_PKEY_GOST01CP_DECRYPT, |
| GOST_R_ERROR_COMPUTING_SHARED_KEY); |
| goto err; |
| } |
| |
| ret = 1; |
| err: |
| if (eph_key) |
| EVP_PKEY_free(eph_key); |
| if (gkt) |
| GOST_KEY_TRANSPORT_free(gkt); |
| return ret; |
| } |
