GOST public key algorithm ENGINE donated to the OpenSSL by Cryptocom.

Very early version, doesn't do much yet, not even added to the build system.

1 files changed, 420 insertions, 0 deletions

diff --git a/engines/ccgost/gost94_keyx.c b/engines/ccgost/gost94_keyx.c
new file mode 100644
index 0000000000..4cf8a0ba80
--- /dev/null
+++ b/engines/ccgost/gost94_keyx.c
@@ -0,0 +1,420 @@
+/**********************************************************************
+ *                             gost94_keyx.c                          *
+ *             Copyright (c) 2005-2006 Cryptocom LTD                  *
+ *         This file is distributed under the same license as OpenSSL *
+ *                                                                    *
+ *     Implements generation and parsing of GOST_KEY_TRANSPORT for    *
+ *     			GOST R 34.10-94 algorithms                            *
+ *																	  *
+ *          Requires OpenSSL 0.9.9 for compilation                    *
+ **********************************************************************/
+#include <string.h>
+#include <openssl/dh.h>
+#include <openssl/rand.h>
+#include <openssl/evp.h>
+#include <openssl/objects.h>
+
+#include "gostkeyx.h"
+#include "gost_asn1.h"
+#include "gost89.h"
+#include "gosthash.h"
+#include "crypt.h"
+#include "e_gost_err.h"
+#include "pmeth.h"
+#include "keywrap.h"
+#include "tools.h"
+/* Common functions for both 94 and 2001 key exchange schemes */
+int decrypt_cryptocom_key(unsigned char *sess_key,int max_key_len,
+		const unsigned char *crypted_key,int crypted_key_len, gost_ctx *ctx)
+{
+	int i;
+	int j;
+	int blocks = crypted_key_len >>3;
+	unsigned char gamma[8];
+	if (max_key_len <crypted_key_len) {
+		GOSTerr(GOST_F_DECRYPT_CRYPTOCOM_KEY,GOST_R_NOT_ENOUGH_SPACE_FOR_KEY);
+		return 0;
+	}	
+	if ((crypted_key_len & 7) !=0) 
+	{
+		GOSTerr(GOST_F_DECRYPT_CRYPTOCOM_KEY,GOST_R_INVALID_ENCRYPTED_KEY_SIZE);
+		return 0;
+	}	
+	for (i=blocks-1;i>0;i--) 
+	{
+		gostcrypt(ctx,crypted_key+(i-1)*8,gamma);
+		for(j=0;j<8;j++) 
+		{
+			sess_key[i*8+j]=gamma[j]^crypted_key[i*8+j];
+		}
+	}	
+	gostcrypt(ctx,sess_key+crypted_key_len-8,gamma);	
+	for(j=0;j<8;j++) 
+	{
+		sess_key[j]=gamma[j]^crypted_key[j];
+	}
+	return 1;
+}
+int encrypt_cryptocom_key(const unsigned char *sess_key,int key_len,
+		unsigned char *crypted_key, gost_ctx *ctx)
+{
+	int i;
+	int j;
+	unsigned char gamma[8];
+	memcpy(gamma,sess_key+key_len-8,8);
+	for (i=0;i<key_len;i+=8)
+	{
+		gostcrypt(ctx,gamma,gamma);
+		for (j=0;j<8;j++)
+			gamma[j]=crypted_key[i+j]=sess_key[i+j]^gamma[j];
+	}
+	return 1;
+}
+/* Implementation of the Diffi-Hellman key agreement scheme based on
+ * GOST-94 keys */
+
+/* Computes Diffie-Hellman key and stores it into buffer in
+ * little-endian byte order as expected by both versions of GOST 94
+ * algorigthm
+ */
+static int compute_pair_key_le(unsigned char *pair_key,BIGNUM *pub_key,DH *dh) 
+{
+	unsigned char be_key[128];
+	int i,key_size;
+	key_size=DH_compute_key(be_key,pub_key,dh);
+	if (!key_size) return 0;
+	memset(pair_key,0,128);
+	for (i=0;i<key_size;i++) {
+		pair_key[i]=be_key[key_size-1-i];
+	}
+	return key_size;	
+}	
+/*
+ * Computes 256 bit key exchange key for CryptoCom variation of GOST 94
+ * algorithm
+ */
+static int make_gost_shared_key(DH *dh,EVP_PKEY *pubk,unsigned char *shared_key) 
+{
+	unsigned char dh_key [128];
+	int i;
+	/* Compute key */
+	memset(dh_key,0,128);
+	if (!compute_pair_key_le(dh_key,((DSA *)EVP_PKEY_get0(pubk))->pub_key,dh)) return 0;	
+	/* Fold it down to 256 bit */
+	/* According to GOST  either 2^1020<p<2^1024 or 
+	 * 2^509<p<2^512, so DH_size can be exactly 128 or exactly 64 only
+	 */
+	
+	if (DH_size(dh)==128) 
+		for (i=0;i<64;i++) {
+			dh_key[i]^=dh_key[64+i];
+		}	
+	for (i=0;i<32;i++) {
+		shared_key[i]=dh_key[i]^dh_key[32+i];
+	}
+	return 1;
+}
+
+static DH *make_ephemeral_key(EVP_PKEY *pubk,BIGNUM *ephemeral_key)
+{
+	DH *dh = DH_new();
+	dh->g = BN_dup(pubk->pkey.dsa->g);
+	dh->p = BN_dup(pubk->pkey.dsa->p);
+	dh->priv_key = BN_dup(ephemeral_key);
+	/* Generate ephemeral key pair */
+	if (!DH_generate_key(dh)) {
+		DH_free(dh);
+		return NULL;
+	}	
+	return dh;
+}	
+/*
+ * Computes 256 bit Key exchange key as specified in RFC 4357 
+ */
+static int make_cp_exchange_key(DH *dh,EVP_PKEY *pubk, unsigned char *shared_key)
+{
+	unsigned char dh_key [128];
+	gost_hash_ctx hash_ctx;
+	memset(dh_key,0,128);
+	if (!compute_pair_key_le(dh_key,((DSA *)(EVP_PKEY_get0(pubk)))->pub_key,dh)) return 0;
+	init_gost_hash_ctx(&hash_ctx,&GostR3411_94_CryptoProParamSet);
+	start_hash(&hash_ctx);
+	hash_block(&hash_ctx,dh_key,128);
+	finish_hash(&hash_ctx,shared_key);
+	done_gost_hash_ctx(&hash_ctx);
+	return 1;
+}	
+/* EVP_PKEY_METHOD callback encrypt for
+ * GOST R 34.10-94 cryptopro modification
+ */
+
+int pkey_GOST94cp_encrypt(EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen, const unsigned char* key, size_t key_len ) 
+{
+	GOST_KEY_TRANSPORT *gkt=NULL;
+	DH *dh = NULL;
+	unsigned char shared_key[32], ukm[8],crypted_key[44];
+	const struct gost_cipher_info *param=get_encryption_params(NULL);
+	EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
+	struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
+	int size=-1;
+	gost_ctx cctx;
+
+
+	if (!(data->eph_seckey)) {
+		GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
+		GOST_R_CTX_NOT_INITIALIZED_FOR_ENCRYPT);
+		return -1;
+	}	
+
+	dh = make_ephemeral_key(pubk,gost_get_priv_key(data->eph_seckey));
+	gost_init(&cctx,param->sblock);	
+	make_cp_exchange_key(dh,pubk,shared_key);
+	if (RAND_bytes(ukm,8)<=0) {
+		GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
+		GOST_R_RANDOM_GENERATOR_FAILURE);
+		return -1;
+	}	
+	keyWrapCryptoPro(&cctx,shared_key,ukm,key,crypted_key);
+	gkt = GOST_KEY_TRANSPORT_new();
+	if (!gkt) {
+		goto memerr;
+	}	
+	if(!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,
+				                ukm,8)) {
+		goto memerr;
+	}	
+	if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,crypted_key+40,4)) {
+		goto memerr;
+	}
+	if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,crypted_key+8,32)) {
+		goto memerr;
+	}
+	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,data->eph_seckey)) {
+		GOSTerr(GOST_F_PKEY_GOST94CP_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);
+	*outlen = i2d_GOST_KEY_TRANSPORT(gkt,&out);
+	if (!size) {
+		GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,GOST_R_ERROR_PACKING_KEY_TRANSPORT_INFO);
+		size=-1;
+	}
+	GOST_KEY_TRANSPORT_free(gkt);
+	DH_free(dh);
+	return 1;	
+memerr:
+		GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
+				GOST_R_MALLOC_FAILURE);
+err:		
+		GOST_KEY_TRANSPORT_free(gkt);
+		DH_free(dh);
+		return -1;
+}
+/* EVP_PKEY_METHOD callback encrypt for
+ * GOST R 34.10-94 cryptocom modification
+ */
+
+int pkey_GOST94cc_encrypt (EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen,  const unsigned char *   key,size_t key_len) 
+{
+	EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
+	struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
+	/* create DH structure filling parameters from passed pub_key */
+	DH *dh = NULL;
+	GOST_KEY_TRANSPORT *gkt = NULL;
+	gost_ctx cctx;
+	EVP_PKEY *newkey=NULL;
+	unsigned char shared_key[32],encrypted_key[32],hmac[4],
+				  iv[8]={0,0,0,0,0,0,0,0};
+
+	if (! data->eph_seckey) {
+		GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
+		GOST_R_CTX_NOT_INITIALIZED_FOR_ENCRYPT);
+		return -1;
+	}	
+	dh = make_ephemeral_key(pubk,gost_get_priv_key(data->eph_seckey));
+	if (!dh) goto err;
+	/* compute shared key */
+	if (!make_gost_shared_key(dh,pubk,shared_key)) 
+	{
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
+		goto err;
+	}	
+	/* encrypt session key */
+	gost_init(&cctx, &GostR3411_94_CryptoProParamSet);
+	gost_key(&cctx,shared_key);
+	encrypt_cryptocom_key(key,key_len,encrypted_key,&cctx);
+	/* compute hmac of session key */
+	if (!gost_mac(&cctx,32,key,32,hmac)) 
+	{
+		DH_free(dh);
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_ERROR_COMPUTING_MAC);
+		return -1;
+    }
+	gkt = GOST_KEY_TRANSPORT_new();
+	if (!gkt) 
+	{
+		DH_free(dh);
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_NO_MEMORY);
+		return -1;
+	}	
+	/* Store IV which is always zero in our case */
+	if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,iv,8))
+	{
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_ERROR_STORING_IV);
+		goto err;
+	}	
+	if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,hmac,4)) 
+	{
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_ERROR_STORING_MAC);
+		goto err;
+	}	
+	if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,encrypted_key,32))
+	{	
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_ERROR_STORING_ENCRYPTED_KEY);
+		goto err;
+	}
+	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,data->eph_seckey)) {
+		GOSTerr(GOST_F_PKEY_GOST94CC_ENCRYPT,GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
+		goto err;
+	}	
+	ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
+	gkt->key_agreement_info->cipher = OBJ_nid2obj(NID_id_Gost28147_89_cc);
+	*outlen = i2d_GOST_KEY_TRANSPORT(gkt,&out);
+err:
+	if (gkt) GOST_KEY_TRANSPORT_free(gkt);
+	if (dh) DH_free(dh);
+	if (newkey) EVP_PKEY_free(newkey);
+	return 1;
+}	
+	
+/* 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) {
+	DH *dh = DH_new();
+	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;
+	EVP_PKEY *priv= EVP_PKEY_CTX_get0_pkey(ctx); 
+	
+	if (!key) {
+		*key_len = 32;
+		return 1;
+	}	
+	
+	dh->g = BN_dup(priv->pkey.dsa->g);
+	dh->p = BN_dup(priv->pkey.dsa->p);
+	dh->priv_key = BN_dup(priv->pkey.dsa->priv_key);
+	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);
+		DH_free(dh);
+		return 0;
+	}	
+	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
+	param = get_encryption_params(gkt->key_agreement_info->cipher);
+	gost_init(&cctx,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);	
+	make_cp_exchange_key(dh,eph_key,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);
+	DH_free(dh);
+	return 1;
+err:
+	EVP_PKEY_free(eph_key);
+	GOST_KEY_TRANSPORT_free(gkt);
+	DH_free(dh);
+	return -1;
+	
+}	
+/* EVP_PKEY_METHOD callback decrypt for
+ * GOST R 34.10-94 cryptocom modification
+ */
+
+int pkey_GOST94cc_decrypt (EVP_PKEY_CTX *pctx, unsigned char *key, size_t *key_len, const unsigned char *in, size_t in_len)
+{
+	/* Form DH params from compute shared key */
+	GOST_KEY_TRANSPORT *gkt = NULL;
+	const unsigned char *p=in;
+	unsigned char shared_key[32];
+	unsigned char hmac[4],hmac_comp[4];
+	unsigned char iv[8];
+	int i;
+	gost_ctx ctx;
+	DH *dh = DH_new();
+	EVP_PKEY *eph_key;
+	EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
+	
+	if (!key) {
+		*key_len = 32;
+		return 1;
+	}
+	/* Construct DH structure from the our GOST private key */
+	dh->g = BN_dup(priv->pkey.dsa->g);
+	dh->p = BN_dup(priv->pkey.dsa->p);
+	dh->priv_key = BN_dup(priv->pkey.dsa->priv_key);
+	/* Parse passed octet string and find out public key, iv and HMAC*/
+	gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
+			in_len);
+	if (!gkt) {
+		GOSTerr(GOST_F_PKEY_GOST94CC_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
+		DH_free(dh);
+		return 0;
+	}	
+	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
+	/* Initialization vector is really ignored here */
+	OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
+	memcpy(iv,gkt->key_agreement_info->eph_iv->data,8);
+	/* HMAC should be computed and checked */
+	OPENSSL_assert(gkt->key_info->imit->length==4);
+	memcpy(hmac,gkt->key_info->imit->data,4);	
+	/* Compute shared key */
+	i=make_gost_shared_key(dh,eph_key,shared_key);
+	EVP_PKEY_free(eph_key);
+	DH_free(dh);
+	if (!i) 
+	{
+		GOSTerr(GOST_F_PKEY_GOST94CC_DECRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
+		GOST_KEY_TRANSPORT_free(gkt);
+		return 0;
+	}
+	/* Decrypt session key */
+	gost_init(&ctx, &GostR3411_94_CryptoProParamSet);
+	gost_key(&ctx,shared_key);
+	
+	if (!decrypt_cryptocom_key(key,*key_len,gkt->key_info->encrypted_key->data, 
+			gkt->key_info->encrypted_key->length, &ctx)) 
+	{
+		GOST_KEY_TRANSPORT_free(gkt);
+		return 0;
+	}
+	GOST_KEY_TRANSPORT_free(gkt);
+	/* check HMAC of session key*/
+	if (!gost_mac(&ctx,32,key,32,hmac_comp)) {
+		GOSTerr(GOST_F_PKEY_GOST94CC_DECRYPT,GOST_R_ERROR_COMPUTING_MAC);
+		return 0;
+    }
+		/* HMAC of session key is not correct */
+    if (memcmp(hmac,hmac_comp,4)!=0) {
+		GOSTerr(GOST_F_PKEY_GOST94CC_DECRYPT,GOST_R_SESSION_KEY_MAC_DOES_NOT_MATCH);
+		return 0;
+	}	
+	return 1; 
+}