crypto/ec/ec_pmeth.c

   1 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
   2  * project 2006.
   3  */
   4 /* ====================================================================
   5  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  *
  19  * 3. All advertising materials mentioning features or use of this
  20  *    software must display the following acknowledgment:
  21  *    "This product includes software developed by the OpenSSL Project
  22  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  23  *
  24  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  25  *    endorse or promote products derived from this software without
  26  *    prior written permission. For written permission, please contact
  27  *    licensing@OpenSSL.org.
  28  *
  29  * 5. Products derived from this software may not be called "OpenSSL"
  30  *    nor may "OpenSSL" appear in their names without prior written
  31  *    permission of the OpenSSL Project.
  32  *
  33  * 6. Redistributions of any form whatsoever must retain the following
  34  *    acknowledgment:
  35  *    "This product includes software developed by the OpenSSL Project
  36  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  39  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  41  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  42  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  47  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  48  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  49  * OF THE POSSIBILITY OF SUCH DAMAGE.
  50  * ====================================================================
  51  *
  52  * This product includes cryptographic software written by Eric Young
  53  * (eay@cryptsoft.com).  This product includes software written by Tim
  54  * Hudson (tjh@cryptsoft.com).
  55  *
  56  */
  57
  58 #include <stdio.h>
  59 #include "cryptlib.h"
  60 #include <openssl/asn1t.h>
  61 #include <openssl/x509.h>
  62 #include <openssl/ec.h>
  63 #include <openssl/ecdsa.h>
  64 #include <openssl/evp.h>
  65 #include "evp_locl.h"
  66
  67 /* EC pkey context structure */
  68
  69 typedef struct
  70         {
  71         /* Key and paramgen group */
  72         EC_GROUP *gen_group;
  73         /* message digest */
  74         const EVP_MD *md;
  75         } EC_PKEY_CTX;
  76
  77 static int pkey_ec_init(EVP_PKEY_CTX *ctx)
  78         {
  79         EC_PKEY_CTX *dctx;
  80         dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX));
  81         if (!dctx)
  82                 return 0;
  83         dctx->gen_group = NULL;
  84         dctx->md = NULL;
  85
  86         ctx->data = dctx;
  87
  88         return 1;
  89         }
  90
  91 static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx)
  92         {
  93         EC_PKEY_CTX *dctx = ctx->data;
  94         if (dctx)
  95                 {
  96                 if (dctx->gen_group)
  97                         EC_GROUP_free(dctx->gen_group);
  98                 OPENSSL_free(dctx);
  99                 }
 100         }
 101
 102 static int pkey_ec_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
 103                                         const unsigned char *tbs, size_t tbslen)
 104         {
 105         int ret, type;
 106         size_t sltmp;
 107         EC_PKEY_CTX *dctx = ctx->data;
 108         EC_KEY *ec = ctx->pkey->pkey.ec;
 109
 110         if (!sig)
 111                 {
 112                 *siglen = ECDSA_size(ec);
 113                 return 1;
 114                 }
 115         else if(*siglen < (size_t)ECDSA_size(ec))
 116                 {
 117                 ECerr(EC_F_PKEY_EC_SIGN, EC_R_BUFFER_TOO_SMALL);
 118                 return 0;
 119                 }
 120
 121         if (dctx->md)
 122                 type = EVP_MD_type(dctx->md);
 123         else
 124                 type = NID_sha1;
 125
 126
 127         ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
 128
 129         if (ret < 0)
 130                 return ret;
 131         *siglen = sltmp;
 132         return 1;
 133         }
 134
 135 static int pkey_ec_verify(EVP_PKEY_CTX *ctx,
 136                                         const unsigned char *sig, size_t siglen,
 137                                         const unsigned char *tbs, size_t tbslen)
 138         {
 139         int ret, type;
 140         EC_PKEY_CTX *dctx = ctx->data;
 141         EC_KEY *ec = ctx->pkey->pkey.ec;
 142
 143         if (dctx->md)
 144                 type = EVP_MD_type(dctx->md);
 145         else
 146                 type = NID_sha1;
 147
 148         ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
 149
 150         return ret;
 151         }
 152
 153 static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
 154         {
 155         int ret;
 156         size_t outlen;
 157         const EC_POINT *pubkey = NULL;
 158         if (!ctx->pkey || !ctx->peerkey)
 159                 {
 160                 ECerr(EC_F_PKEY_EC_DERIVE, EC_R_KEYS_NOT_SET);
 161                 return 0;
 162                 }
 163
 164         if (!key)
 165                 {
 166                 const EC_GROUP *group;
 167                 group = EC_KEY_get0_group(ctx->pkey->pkey.ec);
 168                 *keylen = (EC_GROUP_get_degree(group) + 7)/8;
 169                 return 1;
 170                 }
 171
 172         pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
 173
 174         /* NB: unlike PKS#3 DH, if *outlen is less than maximum size this is
 175          * not an error, the result is truncated.
 176          */
 177
 178         outlen = *keylen;
 179
 180         ret = ECDH_compute_key(key, outlen, pubkey, ctx->pkey->pkey.ec, 0);
 181         if (ret < 0)
 182                 return ret;
 183         *keylen = ret;
 184         return 1;
 185         }
 186
 187 static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 188         {
 189         EC_PKEY_CTX *dctx = ctx->data;
 190         EC_GROUP *group;
 191         switch (type)
 192                 {
 193                 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
 194                 group = EC_GROUP_new_by_curve_name(p1);
 195                 if (group == NULL)
 196                         {
 197                         ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_CURVE);
 198                         return 0;
 199                         }
 200                 if (dctx->gen_group)
 201                         EC_GROUP_free(dctx->gen_group);
 202                 dctx->gen_group = group;
 203                 return 1;
 204
 205                 case EVP_PKEY_CTRL_MD:
 206                 if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1)
 207                         {
 208                         ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_DIGEST_TYPE);
 209                         return 0;
 210                         }
 211                 dctx->md = p2;
 212                 return 1;
 213
 214                 case EVP_PKEY_CTRL_PEER_KEY:
 215                 /* Default behaviour is OK */
 216                 return 1;
 217
 218                 default:
 219                 return -2;
 220
 221                 }
 222         }
 223
 224 static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
 225                         const char *type, const char *value)
 226         {
 227         if (!strcmp(type, "ec_paramgen_curve"))
 228                 {
 229                 int nid;
 230                 nid = OBJ_sn2nid(value);
 231                 if (nid == NID_undef)
 232                         nid = OBJ_ln2nid(value);
 233                 if (nid == NID_undef)
 234                         {
 235                         ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_CURVE);
 236                         return 0;
 237                         }
 238                 return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
 239                 }
 240         return -2;
 241         }
 242
 243 static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
 244         {
 245         EC_KEY *ec = NULL;
 246         EC_PKEY_CTX *dctx = ctx->data;
 247         int ret = 0;
 248         if (dctx->gen_group == NULL)
 249                 {
 250                 ECerr(EC_F_PKEY_EC_PARAMGEN, EC_R_NO_PARAMETERS_SET);
 251                 return 0;
 252                 }
 253         ec = EC_KEY_new();
 254         if (!ec)
 255                 return 0;
 256         ret = EC_KEY_set_group(ec, dctx->gen_group);
 257         if (ret)
 258                 EVP_PKEY_assign_EC_KEY(pkey, ec);
 259         else
 260                 EC_KEY_free(ec);
 261         return ret;
 262         }
 263
 264 static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
 265         {
 266         EC_KEY *ec = NULL;
 267         if (ctx->pkey == NULL)
 268                 {
 269                 ECerr(EC_F_PKEY_EC_KEYGEN, EC_R_NO_PARAMETERS_SET);
 270                 return 0;
 271                 }
 272         ec = EC_KEY_new();
 273         if (!ec)
 274                 return 0;
 275         EVP_PKEY_assign_EC_KEY(pkey, ec);
 276         /* Note: if error return, pkey is freed by parent routine */
 277         if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
 278                 return 0;
 279         return EC_KEY_generate_key(pkey->pkey.ec);
 280         }
 281
 282 const EVP_PKEY_METHOD ec_pkey_meth =
 283         {
 284         EVP_PKEY_EC,
 285         0,
 286         pkey_ec_init,
 287         pkey_ec_cleanup,
 288
 289         0,
 290         pkey_ec_paramgen,
 291
 292         0,
 293         pkey_ec_keygen,
 294
 295         0,
 296         pkey_ec_sign,
 297
 298         0,
 299         pkey_ec_verify,
 300
 301         0,0,
 302
 303         0,0,0,0,
 304
 305         0,0,
 306
 307         0,0,
 308
 309         0,
 310         pkey_ec_derive,
 311
 312         pkey_ec_ctrl,
 313         pkey_ec_ctrl_str
 314
 315         };