release/src/router/openssl/engines/ccgost/gost94_keyx.c

   1 /**********************************************************************
   2  *                             gost94_keyx.c                          *
   3  *             Copyright (c) 2005-2006 Cryptocom LTD                  *
   4  *         This file is distributed under the same license as OpenSSL *
   5  *                                                                    *
   6  *     Implements generation and parsing of GOST_KEY_TRANSPORT for    *
   7  *              GOST R 34.10-94 algorithms                            *
   8  *                                                                    *
   9  *          Requires OpenSSL 0.9.9 for compilation                    *
  10  **********************************************************************/
  11 #include <string.h>
  12 #include <openssl/dh.h>
  13 #include <openssl/rand.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/objects.h>
  16
  17 #include "gost89.h"
  18 #include "gosthash.h"
  19 #include "e_gost_err.h"
  20 #include "gost_keywrap.h"
  21 #include "gost_lcl.h"
  22 /* Common functions for both 94 and 2001 key exchange schemes */
  23 /*
  24  * Implementation of the Diffi-Hellman key agreement scheme based on GOST-94
  25  * keys
  26  */
  27
  28 /*
  29  * Computes Diffie-Hellman key and stores it into buffer in little-endian
  30  * byte order as expected by both versions of GOST 94 algorithm
  31  */
  32 static int compute_pair_key_le(unsigned char *pair_key, BIGNUM *pub_key,
  33                                DH *dh)
  34 {
  35     unsigned char be_key[128];
  36     int i, key_size;
  37     key_size = DH_compute_key(be_key, pub_key, dh);
  38     if (!key_size)
  39         return 0;
  40     memset(pair_key, 0, 128);
  41     for (i = 0; i < key_size; i++) {
  42         pair_key[i] = be_key[key_size - 1 - i];
  43     }
  44     return key_size;
  45 }
  46
  47 /*
  48  * Computes 256 bit Key exchange key as specified in RFC 4357
  49  */
  50 static int make_cp_exchange_key(BIGNUM *priv_key, EVP_PKEY *pubk,
  51                                 unsigned char *shared_key)
  52 {
  53     unsigned char dh_key[128];
  54     int ret;
  55     gost_hash_ctx hash_ctx;
  56     DH *dh = DH_new();
  57
  58     if (!dh)
  59         return 0;
  60     memset(dh_key, 0, 128);
  61     dh->g = BN_dup(pubk->pkey.dsa->g);
  62     dh->p = BN_dup(pubk->pkey.dsa->p);
  63     dh->priv_key = BN_dup(priv_key);
  64     ret =
  65         compute_pair_key_le(dh_key, ((DSA *)(EVP_PKEY_get0(pubk)))->pub_key,
  66                             dh);
  67     DH_free(dh);
  68     if (!ret)
  69         return 0;
  70     init_gost_hash_ctx(&hash_ctx, &GostR3411_94_CryptoProParamSet);
  71     start_hash(&hash_ctx);
  72     hash_block(&hash_ctx, dh_key, 128);
  73     finish_hash(&hash_ctx, shared_key);
  74     done_gost_hash_ctx(&hash_ctx);
  75     return 1;
  76 }
  77
  78 /* EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-94 */
  79
  80 int pkey_gost94_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
  81 {
  82     EVP_PKEY *pubk = EVP_PKEY_CTX_get0_peerkey(ctx);
  83     EVP_PKEY *mykey = EVP_PKEY_CTX_get0_pkey(ctx);
  84     *keylen = 32;
  85     if (key == NULL)
  86         return 1;
  87
  88     return make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, key);
  89 }
  90
  91 /*
  92  * EVP_PKEY_METHOD callback encrypt for GOST R 34.10-94 cryptopro
  93  * modification
  94  */
  95
  96 int pkey_GOST94cp_encrypt(EVP_PKEY_CTX *ctx, unsigned char *out,
  97                           size_t *outlen, const unsigned char *key,
  98                           size_t key_len)
  99 {
 100     GOST_KEY_TRANSPORT *gkt = NULL;
 101     unsigned char shared_key[32], ukm[8], crypted_key[44];
 102     const struct gost_cipher_info *param = get_encryption_params(NULL);
 103     EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
 104     struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
 105     gost_ctx cctx;
 106     int key_is_ephemeral = 1;
 107     int tmp_outlen;
 108     EVP_PKEY *mykey = EVP_PKEY_CTX_get0_peerkey(ctx);
 109
 110     /* Do not use vizir cipher parameters with cryptopro */
 111     if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
 112         && param == gost_cipher_list) {
 113         param = gost_cipher_list + 1;
 114     }
 115
 116     if (mykey) {
 117         /* If key already set, it is not ephemeral */
 118         key_is_ephemeral = 0;
 119         if (!gost_get0_priv_key(mykey)) {
 120             GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
 121                     GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
 122             goto err;
 123         }
 124     } else {
 125         /* Otherwise generate ephemeral key */
 126         key_is_ephemeral = 1;
 127         if (out) {
 128             mykey = EVP_PKEY_new();
 129             EVP_PKEY_assign(mykey, EVP_PKEY_base_id(pubk), DSA_new());
 130             EVP_PKEY_copy_parameters(mykey, pubk);
 131             if (!gost_sign_keygen(EVP_PKEY_get0(mykey))) {
 132                 goto err;
 133             }
 134         }
 135     }
 136     if (out)
 137         make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, shared_key);
 138     if (data->shared_ukm) {
 139         memcpy(ukm, data->shared_ukm, 8);
 140     } else if (out) {
 141         if (RAND_bytes(ukm, 8) <= 0) {
 142             GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
 143                     GOST_R_RANDOM_GENERATOR_FAILURE);
 144             goto err;
 145         }
 146     }
 147
 148     if (out) {
 149         gost_init(&cctx, param->sblock);
 150         keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
 151     }
 152     gkt = GOST_KEY_TRANSPORT_new();
 153     if (!gkt) {
 154         goto memerr;
 155     }
 156     if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
 157         goto memerr;
 158     }
 159     if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
 160         goto memerr;
 161     }
 162     if (!ASN1_OCTET_STRING_set
 163         (gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
 164         goto memerr;
 165     }
 166     if (key_is_ephemeral) {
 167         if (!X509_PUBKEY_set
 168             (&gkt->key_agreement_info->ephem_key, out ? mykey : pubk)) {
 169             GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
 170                     GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
 171             goto err;
 172         }
 173         if (out)
 174             EVP_PKEY_free(mykey);
 175     }
 176     ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
 177     gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
 178     tmp_outlen = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL);
 179     if (tmp_outlen <= 0) {
 180         GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
 181                 GOST_R_ERROR_PACKING_KEY_TRANSPORT_INFO);
 182         goto err;
 183     }
 184     *outlen = tmp_outlen;
 185     if (!key_is_ephemeral) {
 186         /* Set control "public key from client certificate used" */
 187         if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
 188             0) {
 189             GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
 190             goto err;
 191         }
 192     }
 193     GOST_KEY_TRANSPORT_free(gkt);
 194     return 1;
 195  memerr:
 196     if (key_is_ephemeral) {
 197         EVP_PKEY_free(mykey);
 198     }
 199     GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, GOST_R_MALLOC_FAILURE);
 200  err:
 201     GOST_KEY_TRANSPORT_free(gkt);
 202     return -1;
 203 }
 204
 205 /*
 206  * EVP_PLEY_METHOD callback decrypt for GOST R 34.10-94 cryptopro
 207  * modification
 208  */
 209 int pkey_GOST94cp_decrypt(EVP_PKEY_CTX *ctx, unsigned char *key,
 210                           size_t *key_len, const unsigned char *in,
 211                           size_t in_len)
 212 {
 213     const unsigned char *p = in;
 214     GOST_KEY_TRANSPORT *gkt = NULL;
 215     unsigned char wrappedKey[44];
 216     unsigned char sharedKey[32];
 217     gost_ctx cctx;
 218     const struct gost_cipher_info *param = NULL;
 219     EVP_PKEY *eph_key = NULL, *peerkey = NULL;
 220     EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(ctx);
 221
 222     if (!key) {
 223         *key_len = 32;
 224         return 1;
 225     }
 226
 227     gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
 228     if (!gkt) {
 229         GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
 230                 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
 231         return 0;
 232     }
 233     eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
 234     if (eph_key) {
 235         if (EVP_PKEY_derive_set_peer(ctx, eph_key) <= 0) {
 236             GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
 237                     GOST_R_INCOMPATIBLE_PEER_KEY);
 238             goto err;
 239         }
 240     } else {
 241         /* Set control "public key from client certificate used" */
 242         if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
 243             0) {
 244             GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
 245             goto err;
 246         }
 247     }
 248     peerkey = EVP_PKEY_CTX_get0_peerkey(ctx);
 249     if (!peerkey) {
 250         GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_NO_PEER_KEY);
 251         goto err;
 252     }
 253
 254     param = get_encryption_params(gkt->key_agreement_info->cipher);
 255     if (!param) {
 256         goto err;
 257     }
 258
 259     gost_init(&cctx, param->sblock);
 260     OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
 261     memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
 262     OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
 263     memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
 264     OPENSSL_assert(gkt->key_info->imit->length == 4);
 265     memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
 266     make_cp_exchange_key(gost_get0_priv_key(priv), peerkey, sharedKey);
 267     if (!keyUnwrapCryptoPro(&cctx, sharedKey, wrappedKey, key)) {
 268         GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
 269                 GOST_R_ERROR_COMPUTING_SHARED_KEY);
 270         goto err;
 271     }
 272
 273     EVP_PKEY_free(eph_key);
 274     GOST_KEY_TRANSPORT_free(gkt);
 275     return 1;
 276  err:
 277     EVP_PKEY_free(eph_key);
 278     GOST_KEY_TRANSPORT_free(gkt);
 279     return -1;
 280 }