/********************************************************************** * 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 #include #include #include #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; }