1 /* Written by Dr Stephen N Henson (steve (at) openssl.org) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 54 * Hudson (tjh (at) cryptsoft.com). */ 55 56 #include <openssl/evp.h> 57 58 #include <string.h> 59 60 #include <openssl/asn1.h> 61 #include <openssl/bn.h> 62 #include <openssl/buf.h> 63 #include <openssl/digest.h> 64 #include <openssl/ec.h> 65 #include <openssl/ec_key.h> 66 #include <openssl/ecdh.h> 67 #include <openssl/ecdsa.h> 68 #include <openssl/err.h> 69 #include <openssl/mem.h> 70 #include <openssl/obj.h> 71 72 #include "internal.h" 73 #include "../ec/internal.h" 74 75 76 typedef struct { 77 /* Key and paramgen group */ 78 EC_GROUP *gen_group; 79 /* message digest */ 80 const EVP_MD *md; 81 } EC_PKEY_CTX; 82 83 84 static int pkey_ec_init(EVP_PKEY_CTX *ctx) { 85 EC_PKEY_CTX *dctx; 86 dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX)); 87 if (!dctx) { 88 return 0; 89 } 90 memset(dctx, 0, sizeof(EC_PKEY_CTX)); 91 92 ctx->data = dctx; 93 94 return 1; 95 } 96 97 static int pkey_ec_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) { 98 EC_PKEY_CTX *dctx, *sctx; 99 if (!pkey_ec_init(dst)) { 100 return 0; 101 } 102 sctx = src->data; 103 dctx = dst->data; 104 105 if (sctx->gen_group) { 106 dctx->gen_group = EC_GROUP_dup(sctx->gen_group); 107 if (!dctx->gen_group) { 108 return 0; 109 } 110 } 111 dctx->md = sctx->md; 112 113 return 1; 114 } 115 116 static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx) { 117 EC_PKEY_CTX *dctx = ctx->data; 118 if (!dctx) { 119 return; 120 } 121 122 EC_GROUP_free(dctx->gen_group); 123 OPENSSL_free(dctx); 124 } 125 126 static int pkey_ec_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *siglen, 127 const uint8_t *tbs, size_t tbslen) { 128 unsigned int sltmp; 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 OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL); 136 return 0; 137 } 138 139 if (!ECDSA_sign(0, tbs, tbslen, sig, &sltmp, ec)) { 140 return 0; 141 } 142 *siglen = (size_t)sltmp; 143 return 1; 144 } 145 146 static int pkey_ec_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t siglen, 147 const uint8_t *tbs, size_t tbslen) { 148 return ECDSA_verify(0, tbs, tbslen, sig, siglen, ctx->pkey->pkey.ec); 149 } 150 151 static int pkey_ec_derive(EVP_PKEY_CTX *ctx, uint8_t *key, 152 size_t *keylen) { 153 int ret; 154 size_t outlen; 155 const EC_POINT *pubkey = NULL; 156 EC_KEY *eckey; 157 158 if (!ctx->pkey || !ctx->peerkey) { 159 OPENSSL_PUT_ERROR(EVP, EVP_R_KEYS_NOT_SET); 160 return 0; 161 } 162 163 eckey = ctx->pkey->pkey.ec; 164 165 if (!key) { 166 const EC_GROUP *group; 167 group = EC_KEY_get0_group(eckey); 168 *keylen = (EC_GROUP_get_degree(group) + 7) / 8; 169 return 1; 170 } 171 pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec); 172 173 /* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is 174 * not an error, the result is truncated. */ 175 176 outlen = *keylen; 177 178 ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0); 179 if (ret < 0) { 180 return 0; 181 } 182 *keylen = ret; 183 return 1; 184 } 185 186 static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) { 187 EC_PKEY_CTX *dctx = ctx->data; 188 EC_GROUP *group; 189 190 switch (type) { 191 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID: 192 group = EC_GROUP_new_by_curve_name(p1); 193 if (group == NULL) { 194 OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_CURVE); 195 return 0; 196 } 197 EC_GROUP_free(dctx->gen_group); 198 dctx->gen_group = group; 199 return 1; 200 201 case EVP_PKEY_CTRL_MD: 202 if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 && 203 EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 && 204 EVP_MD_type((const EVP_MD *)p2) != NID_sha224 && 205 EVP_MD_type((const EVP_MD *)p2) != NID_sha256 && 206 EVP_MD_type((const EVP_MD *)p2) != NID_sha384 && 207 EVP_MD_type((const EVP_MD *)p2) != NID_sha512) { 208 OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_DIGEST_TYPE); 209 return 0; 210 } 211 dctx->md = p2; 212 return 1; 213 214 case EVP_PKEY_CTRL_GET_MD: 215 *(const EVP_MD **)p2 = dctx->md; 216 return 1; 217 218 case EVP_PKEY_CTRL_PEER_KEY: 219 /* Default behaviour is OK */ 220 return 1; 221 222 default: 223 OPENSSL_PUT_ERROR(EVP, EVP_R_COMMAND_NOT_SUPPORTED); 224 return 0; 225 } 226 } 227 228 static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) { 229 EC_KEY *ec = NULL; 230 EC_PKEY_CTX *dctx = ctx->data; 231 int ret = 0; 232 233 if (dctx->gen_group == NULL) { 234 OPENSSL_PUT_ERROR(EVP, EVP_R_NO_PARAMETERS_SET); 235 return 0; 236 } 237 ec = EC_KEY_new(); 238 if (!ec) { 239 return 0; 240 } 241 ret = EC_KEY_set_group(ec, dctx->gen_group); 242 if (ret) { 243 EVP_PKEY_assign_EC_KEY(pkey, ec); 244 } else { 245 EC_KEY_free(ec); 246 } 247 return ret; 248 } 249 250 static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) { 251 EC_KEY *ec = NULL; 252 EC_PKEY_CTX *dctx = ctx->data; 253 if (ctx->pkey == NULL && dctx->gen_group == NULL) { 254 OPENSSL_PUT_ERROR(EVP, EVP_R_NO_PARAMETERS_SET); 255 return 0; 256 } 257 ec = EC_KEY_new(); 258 if (!ec) { 259 return 0; 260 } 261 EVP_PKEY_assign_EC_KEY(pkey, ec); 262 if (ctx->pkey) { 263 /* Note: if error return, pkey is freed by parent routine */ 264 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) { 265 return 0; 266 } 267 } else { 268 if (!EC_KEY_set_group(ec, dctx->gen_group)) { 269 return 0; 270 } 271 } 272 return EC_KEY_generate_key(pkey->pkey.ec); 273 } 274 275 const EVP_PKEY_METHOD ec_pkey_meth = { 276 EVP_PKEY_EC, 0 /* flags */, pkey_ec_init, 277 pkey_ec_copy, pkey_ec_cleanup, 0 /* paramgen_init */, 278 pkey_ec_paramgen, 0 /* keygen_init */, pkey_ec_keygen, 279 0 /* sign_init */, pkey_ec_sign, 0 /* verify_init */, 280 pkey_ec_verify, 0 /* encrypt_init */, 0 /* encrypt */, 281 0 /* decrypt_init */, 0 /* decrypt */, 0 /* derive_init */, 282 pkey_ec_derive, pkey_ec_ctrl, 283 }; 284
