/*
* 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:
EVP_PKEY_free(eph_key);
GOST_KEY_TRANSPORT_free(gkt);
return ret;
}
/* EVP_PLEY_METHOD callback decrypt for
* GOST R 34.10-94 cryptopro modification
*/
int pkey_GOST94cp_decrypt(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *key_len,const unsigned char *in, size_t in_len) {
const unsigned char *p = in;
GOST_KEY_TRANSPORT *gkt = NULL;
unsigned char wrappedKey[44];
unsigned char sharedKey[32];
gost_ctx cctx;
const struct gost_cipher_info *param=NULL;
EVP_PKEY *eph_key=NULL, *peerkey=NULL;
EVP_PKEY *priv= EVP_PKEY_CTX_get0_pkey(ctx);
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_GOST94CP_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
return 0;
}
eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
if (eph_key)
{
if (EVP_PKEY_derive_set_peer(ctx, eph_key) <= 0)
{
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
GOST_R_INCOMPATIBLE_PEER_KEY);
goto err;
}
}
else
{
/* Set control "public key from client certificate used" */
if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <= 0)
{
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
GOST_R_CTRL_CALL_FAILED);
goto err;
}
}
peerkey = EVP_PKEY_CTX_get0_peerkey(ctx);
if (!peerkey)
{
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
GOST_R_NO_PEER_KEY);
goto err;
}
param = get_encryption_params(gkt->key_agreement_info->cipher);
gost_init(&cctx,param->sblock);
OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
TINYCLR_SSL_MEMCPY(wrappedKey,gkt->key_agreement_info->eph_iv->data,8);
OPENSSL_assert(gkt->key_info->encrypted_key->length==32);
TINYCLR_SSL_MEMCPY(wrappedKey+8,gkt->key_info->encrypted_key->data,32);
OPENSSL_assert(gkt->key_info->imit->length==4);
TINYCLR_SSL_MEMCPY(wrappedKey+40,gkt->key_info->imit->data,4);
make_cp_exchange_key(gost_get0_priv_key(priv),peerkey,sharedKey);
if (!keyUnwrapCryptoPro(&cctx,sharedKey,wrappedKey,key))
{
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
GOST_R_ERROR_COMPUTING_SHARED_KEY);
goto err;
}
EVP_PKEY_free(eph_key);
GOST_KEY_TRANSPORT_free(gkt);
return 1;
err:
EVP_PKEY_free(eph_key);
GOST_KEY_TRANSPORT_free(gkt);
return -1;
}
