1 /* $OpenBSD: ec_pmeth.c,v 1.10 2017/01/29 17:49:23 beck Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2006. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <stdio.h> 60 #include <string.h> 61 62 #include <openssl/asn1t.h> 63 #include <openssl/ec.h> 64 #include <openssl/ecdsa.h> 65 #include <openssl/err.h> 66 #include <openssl/evp.h> 67 #include <openssl/x509.h> 68 69 #include "evp_locl.h" 70 71 /* EC pkey context structure */ 72 73 typedef struct { 74 /* Key and paramgen group */ 75 EC_GROUP *gen_group; 76 /* message digest */ 77 const EVP_MD *md; 78 } EC_PKEY_CTX; 79 80 static int 81 pkey_ec_init(EVP_PKEY_CTX * ctx) 82 { 83 EC_PKEY_CTX *dctx; 84 dctx = malloc(sizeof(EC_PKEY_CTX)); 85 if (!dctx) 86 return 0; 87 dctx->gen_group = NULL; 88 dctx->md = NULL; 89 90 ctx->data = dctx; 91 92 return 1; 93 } 94 95 static int 96 pkey_ec_copy(EVP_PKEY_CTX * dst, EVP_PKEY_CTX * src) 97 { 98 EC_PKEY_CTX *dctx, *sctx; 99 if (!pkey_ec_init(dst)) 100 return 0; 101 sctx = src->data; 102 dctx = dst->data; 103 if (sctx->gen_group) { 104 dctx->gen_group = EC_GROUP_dup(sctx->gen_group); 105 if (!dctx->gen_group) 106 return 0; 107 } 108 dctx->md = sctx->md; 109 return 1; 110 } 111 112 static void 113 pkey_ec_cleanup(EVP_PKEY_CTX * ctx) 114 { 115 EC_PKEY_CTX *dctx = ctx->data; 116 if (dctx) { 117 EC_GROUP_free(dctx->gen_group); 118 free(dctx); 119 } 120 } 121 122 static int 123 pkey_ec_sign(EVP_PKEY_CTX * ctx, unsigned char *sig, size_t * siglen, 124 const unsigned char *tbs, size_t tbslen) 125 { 126 int ret, type; 127 unsigned int sltmp; 128 EC_PKEY_CTX *dctx = ctx->data; 129 EC_KEY *ec = ctx->pkey->pkey.ec; 130 131 if (!sig) { 132 *siglen = ECDSA_size(ec); 133 return 1; 134 } else if (*siglen < (size_t) ECDSA_size(ec)) { 135 ECerror(EC_R_BUFFER_TOO_SMALL); 136 return 0; 137 } 138 if (dctx->md) 139 type = EVP_MD_type(dctx->md); 140 else 141 type = NID_sha1; 142 143 144 ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec); 145 146 if (ret <= 0) 147 return ret; 148 *siglen = (size_t) sltmp; 149 return 1; 150 } 151 152 static int 153 pkey_ec_verify(EVP_PKEY_CTX * ctx, 154 const unsigned char *sig, size_t siglen, 155 const unsigned char *tbs, size_t tbslen) 156 { 157 int ret, type; 158 EC_PKEY_CTX *dctx = ctx->data; 159 EC_KEY *ec = ctx->pkey->pkey.ec; 160 161 if (dctx->md) 162 type = EVP_MD_type(dctx->md); 163 else 164 type = NID_sha1; 165 166 ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec); 167 168 return ret; 169 } 170 171 static int 172 pkey_ec_derive(EVP_PKEY_CTX * ctx, unsigned char *key, size_t * keylen) 173 { 174 int ret; 175 size_t outlen; 176 const EC_POINT *pubkey = NULL; 177 if (!ctx->pkey || !ctx->peerkey) { 178 ECerror(EC_R_KEYS_NOT_SET); 179 return 0; 180 } 181 if (!key) { 182 const EC_GROUP *group; 183 group = EC_KEY_get0_group(ctx->pkey->pkey.ec); 184 *keylen = (EC_GROUP_get_degree(group) + 7) / 8; 185 return 1; 186 } 187 pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec); 188 189 /* 190 * NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is 191 * not an error, the result is truncated. 192 */ 193 194 outlen = *keylen; 195 196 ret = ECDH_compute_key(key, outlen, pubkey, ctx->pkey->pkey.ec, 0); 197 if (ret < 0) 198 return ret; 199 *keylen = ret; 200 return 1; 201 } 202 203 static int 204 pkey_ec_ctrl(EVP_PKEY_CTX * ctx, int type, int p1, void *p2) 205 { 206 EC_PKEY_CTX *dctx = ctx->data; 207 EC_GROUP *group; 208 switch (type) { 209 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID: 210 group = EC_GROUP_new_by_curve_name(p1); 211 if (group == NULL) { 212 ECerror(EC_R_INVALID_CURVE); 213 return 0; 214 } 215 EC_GROUP_free(dctx->gen_group); 216 dctx->gen_group = group; 217 return 1; 218 219 case EVP_PKEY_CTRL_MD: 220 if (EVP_MD_type((const EVP_MD *) p2) != NID_sha1 && 221 EVP_MD_type((const EVP_MD *) p2) != NID_ecdsa_with_SHA1 && 222 EVP_MD_type((const EVP_MD *) p2) != NID_sha224 && 223 EVP_MD_type((const EVP_MD *) p2) != NID_sha256 && 224 EVP_MD_type((const EVP_MD *) p2) != NID_sha384 && 225 EVP_MD_type((const EVP_MD *) p2) != NID_sha512) { 226 ECerror(EC_R_INVALID_DIGEST_TYPE); 227 return 0; 228 } 229 dctx->md = p2; 230 return 1; 231 232 case EVP_PKEY_CTRL_PEER_KEY: 233 /* Default behaviour is OK */ 234 case EVP_PKEY_CTRL_DIGESTINIT: 235 case EVP_PKEY_CTRL_PKCS7_SIGN: 236 case EVP_PKEY_CTRL_CMS_SIGN: 237 return 1; 238 239 default: 240 return -2; 241 242 } 243 } 244 245 static int 246 pkey_ec_ctrl_str(EVP_PKEY_CTX * ctx, 247 const char *type, const char *value) 248 { 249 if (!strcmp(type, "ec_paramgen_curve")) { 250 int nid; 251 nid = EC_curve_nist2nid(value); 252 if (nid == NID_undef) 253 nid = OBJ_sn2nid(value); 254 if (nid == NID_undef) 255 nid = OBJ_ln2nid(value); 256 if (nid == NID_undef) { 257 ECerror(EC_R_INVALID_CURVE); 258 return 0; 259 } 260 return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid); 261 } 262 return -2; 263 } 264 265 static int 266 pkey_ec_paramgen(EVP_PKEY_CTX * ctx, EVP_PKEY * pkey) 267 { 268 EC_KEY *ec = NULL; 269 EC_PKEY_CTX *dctx = ctx->data; 270 int ret = 0; 271 if (dctx->gen_group == NULL) { 272 ECerror(EC_R_NO_PARAMETERS_SET); 273 return 0; 274 } 275 ec = EC_KEY_new(); 276 if (!ec) 277 return 0; 278 ret = EC_KEY_set_group(ec, dctx->gen_group); 279 if (ret) 280 EVP_PKEY_assign_EC_KEY(pkey, ec); 281 else 282 EC_KEY_free(ec); 283 return ret; 284 } 285 286 static int 287 pkey_ec_keygen(EVP_PKEY_CTX * ctx, EVP_PKEY * pkey) 288 { 289 EC_KEY *ec = NULL; 290 if (ctx->pkey == NULL) { 291 ECerror(EC_R_NO_PARAMETERS_SET); 292 return 0; 293 } 294 ec = EC_KEY_new(); 295 if (!ec) 296 return 0; 297 EVP_PKEY_assign_EC_KEY(pkey, ec); 298 /* Note: if error return, pkey is freed by parent routine */ 299 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) 300 return 0; 301 return EC_KEY_generate_key(pkey->pkey.ec); 302 } 303 304 const EVP_PKEY_METHOD ec_pkey_meth = { 305 .pkey_id = EVP_PKEY_EC, 306 307 .init = pkey_ec_init, 308 .copy = pkey_ec_copy, 309 .cleanup = pkey_ec_cleanup, 310 311 .paramgen = pkey_ec_paramgen, 312 313 .keygen = pkey_ec_keygen, 314 315 .sign = pkey_ec_sign, 316 317 .verify = pkey_ec_verify, 318 319 .derive = pkey_ec_derive, 320 321 .ctrl = pkey_ec_ctrl, 322 .ctrl_str = pkey_ec_ctrl_str 323 }; 324