3b5a78ac3d3653f129943d3367aba12124241d7b
[openssl.git] / engines / ccgost / gost2001_keyx.c
1 /**********************************************************************
2  *                          gost_keyx.c                               *
3  *             Copyright (c) 2005-2006 Cryptocom LTD                  *
4  *         This file is distributed under the same license as OpenSSL *
5  *                                                                    *
6  *   VK0 34.10-2001 key exchange and GOST R 34.10-2001                *
7  *   based PKCS7/SMIME support                                        *
8  *          Requires OpenSSL 0.9.9 for compilation                    *
9  **********************************************************************/
10 #include <openssl/evp.h>
11 #include <openssl/rand.h>
12 #include <string.h>
13 #include <openssl/objects.h>
14 #include "gost89.h"
15 #include "gosthash.h"
16 #include "e_gost_err.h"
17 #include "gost_keywrap.h"
18 #include "gost_lcl.h"
19 #include "gost2001_keyx.h"
20
21
22
23 /* Implementation of CryptoPro VKO 34.10-2001 algorithm */
24 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)
25         {
26         unsigned char ukm_be[8],databuf[64],hashbuf[64];
27         BIGNUM *UKM=NULL,*p=NULL,*order=NULL,*X=NULL,*Y=NULL;
28         const BIGNUM* key=EC_KEY_get0_private_key(priv_key);
29         EC_POINT *pnt=EC_POINT_new(EC_KEY_get0_group(priv_key));
30         int i;
31         gost_hash_ctx hash_ctx;
32         BN_CTX *ctx = BN_CTX_new();
33
34         for (i=0;i<8;i++)
35                 {
36                 ukm_be[7-i]=ukm[i];
37                 }
38         BN_CTX_start(ctx);
39         UKM=getbnfrombuf(ukm_be,8);
40         p=BN_CTX_get(ctx);
41         order = BN_CTX_get(ctx);
42         X=BN_CTX_get(ctx);
43         Y=BN_CTX_get(ctx);
44         EC_GROUP_get_order(EC_KEY_get0_group(priv_key),order,ctx);
45         BN_mod_mul(p,key,UKM,order,ctx);        
46         EC_POINT_mul(EC_KEY_get0_group(priv_key),pnt,NULL,pub_key,p,ctx);
47         EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(priv_key),
48                 pnt,X,Y,ctx);
49         /*Serialize elliptic curve point same way as we do it when saving
50          * key */
51         store_bignum(Y,databuf,32);
52         store_bignum(X,databuf+32,32);
53         /* And reverse byte order of whole buffer */
54         for (i=0;i<64;i++)
55                 {
56                 hashbuf[63-i]=databuf[i];
57                 }
58         init_gost_hash_ctx(&hash_ctx,&GostR3411_94_CryptoProParamSet);
59         start_hash(&hash_ctx);
60         hash_block(&hash_ctx,hashbuf,64);
61         finish_hash(&hash_ctx,shared_key);
62         done_gost_hash_ctx(&hash_ctx);
63         BN_free(UKM);
64         BN_CTX_end(ctx);
65         BN_CTX_free(ctx);
66         EC_POINT_free(pnt);
67         return 32;
68         }
69
70
71 /*
72  * EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-2001
73  * algorithm
74  */
75 int pkey_gost2001_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
76 {
77         /* Public key of peer in the ctx field peerkey
78          * Our private key in the ctx pkey
79          * ukm is in the algorithm specific context data
80          */
81         EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx);
82         EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx);
83         struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
84         
85         if (!data->shared_ukm) {
86                 GOSTerr(GOST_F_PKEY_GOST2001_DERIVE, GOST_R_UKM_NOT_SET);
87                 return 0;
88         }       
89
90         if (key == NULL) {
91                 *keylen = 32;
92                 return 32;
93         }       
94         
95         *keylen=VKO_compute_key(key, 32, EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
96                 (EC_KEY *)EVP_PKEY_get0(my_key),data->shared_ukm);
97         return 1;       
98 }
99
100
101
102
103 /*  
104  * EVP_PKEY_METHOD callback encrypt  
105  * Implementation of GOST2001 key transport, cryptocom variation 
106  */
107 /* Generates ephemeral key based on pubk algorithm
108  * computes shared key using VKO and returns filled up
109  * GOST_KEY_TRANSPORT structure
110  */
111
112 /*  
113  * EVP_PKEY_METHOD callback encrypt  
114  * Implementation of GOST2001 key transport, cryptopo variation 
115  */
116
117 int pkey_GOST01cp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out, size_t *out_len, const unsigned char *key,size_t key_len) 
118         {
119         GOST_KEY_TRANSPORT *gkt=NULL; 
120         EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
121         struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
122         const struct gost_cipher_info *param=get_encryption_params(NULL);
123         unsigned char ukm[8], shared_key[32], crypted_key[44];
124         int ret=0;
125         int key_is_ephemeral=1;
126         gost_ctx cctx;
127         EVP_PKEY *sec_key=EVP_PKEY_CTX_get0_peerkey(pctx);
128         if (data->shared_ukm) 
129                 {
130                 memcpy(ukm, data->shared_ukm,8);
131                 } 
132         else if (out) 
133                 {
134                 
135                 if (RAND_bytes(ukm,8)<=0)
136                         {
137                         GOSTerr(GOST_F_PKEY_GOST01CP_ENCRYPT,
138                                 GOST_R_RANDOM_GENERATOR_FAILURE);
139                         return 0;
140                         }       
141                 }       
142         /* Check for private key in the peer_key of context */  
143         if (sec_key) 
144                 {
145                 key_is_ephemeral=0;
146                 if (!gost_get0_priv_key(sec_key)) 
147                         {
148                         GOSTerr(GOST_F_PKEY_GOST01CP_ENCRYPT,
149                         GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
150                         goto err;
151                         }       
152                 } 
153         else 
154                 {
155                 key_is_ephemeral=1;
156                 if (out) 
157                         {
158                         sec_key = EVP_PKEY_new();
159                         EVP_PKEY_assign(sec_key,EVP_PKEY_base_id(pubk),EC_KEY_new());
160                         EVP_PKEY_copy_parameters(sec_key,pubk);
161                         if (!gost2001_keygen(EVP_PKEY_get0(sec_key))) 
162                                 {
163                                 goto err;
164                                 }       
165                         }
166                 }
167         if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS) && param ==  gost_cipher_list)
168                 {
169                 param= gost_cipher_list+1;
170                 }       
171     if (out) 
172                 {
173                 VKO_compute_key(shared_key,32,EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),EVP_PKEY_get0(sec_key),ukm);
174                 gost_init(&cctx,param->sblock); 
175                 keyWrapCryptoPro(&cctx,shared_key,ukm,key,crypted_key);
176                 }
177         gkt = GOST_KEY_TRANSPORT_new();
178         if (!gkt)
179                 {
180                 goto err;
181                 }       
182         if(!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,
183                         ukm,8))
184                 {
185                 goto err;
186                 }       
187         if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,crypted_key+40,4))
188                 {
189                 goto err;
190                 }
191         if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,crypted_key+8,32))
192                 {
193                 goto err;
194                 }
195         if (key_is_ephemeral) { 
196                 if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,out?sec_key:pubk))
197                         {
198                         GOSTerr(GOST_F_PKEY_GOST01CP_ENCRYPT,
199                                         GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
200                         goto err;
201                         }       
202         }               
203         ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
204         gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
205         if (key_is_ephemeral && sec_key) EVP_PKEY_free(sec_key);
206         if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt,out?&out:NULL))>0) ret =1;
207         GOST_KEY_TRANSPORT_free(gkt);
208         return ret;     
209         err:            
210         if (key_is_ephemeral && sec_key) EVP_PKEY_free(sec_key);
211         GOST_KEY_TRANSPORT_free(gkt);
212         return -1;
213         }
214 /*  
215  * EVP_PKEY_METHOD callback decrypt  
216  * Implementation of GOST2001 key transport, cryptopo variation 
217  */
218 int pkey_GOST01cp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key, size_t * key_len, const unsigned char *in, size_t in_len)
219         {
220         const unsigned char *p = in;
221         EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
222         GOST_KEY_TRANSPORT *gkt = NULL;
223         int ret=0;      
224         unsigned char wrappedKey[44];
225         unsigned char sharedKey[32];
226         gost_ctx ctx;
227         const struct gost_cipher_info *param=NULL;
228         EVP_PKEY *eph_key=NULL;
229
230         if (!key)
231                 {
232                 *key_len = 32;
233                 return 1;
234                 }       
235         gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
236                 in_len);
237         if (!gkt)
238                 {
239                 GOSTerr(GOST_F_PKEY_GOST01CP_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
240                 return -1;
241                 }       
242     
243         eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
244         if (!eph_key) {
245                 eph_key = EVP_PKEY_CTX_get0_peerkey(pctx);
246                 if (! eph_key) {
247                         GOSTerr(GOST_F_PKEY_GOST01CP_DECRYPT,
248                                 GOST_R_NO_PEER_KEY);
249                         goto err;
250                 }
251                 /* Increment reference count of peer key */
252                 CRYPTO_add(&(eph_key->references),1 ,CRYPTO_LOCK_EVP_PKEY);
253         }       
254                 
255         param = get_encryption_params(gkt->key_agreement_info->cipher);
256         gost_init(&ctx,param->sblock);  
257         OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
258         memcpy(wrappedKey,gkt->key_agreement_info->eph_iv->data,8);
259         OPENSSL_assert(gkt->key_info->encrypted_key->length==32);
260         memcpy(wrappedKey+8,gkt->key_info->encrypted_key->data,32);
261         OPENSSL_assert(gkt->key_info->imit->length==4);
262         memcpy(wrappedKey+40,gkt->key_info->imit->data,4);      
263         VKO_compute_key(sharedKey,32,EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)),
264                 EVP_PKEY_get0(priv),wrappedKey);
265         if (!keyUnwrapCryptoPro(&ctx,sharedKey,wrappedKey,key))
266                 {
267                 GOSTerr(GOST_F_PKEY_GOST01CP_DECRYPT,
268                         GOST_R_ERROR_COMPUTING_SHARED_KEY);
269                 goto err;
270                 }       
271                                 
272         EVP_PKEY_free(eph_key);
273         GOST_KEY_TRANSPORT_free(gkt);
274         ret=1;
275 err:    
276         return ret;
277         }