1/* Written by Dr Stephen N Henson (steve@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@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#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 76typedef 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 84static 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 97static 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 116static 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 126static int pkey_ec_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *siglen, 127 const uint8_t *tbs, size_t tbslen) { 128 int type; 129 unsigned int sltmp; 130 EC_PKEY_CTX *dctx = ctx->data; 131 EC_KEY *ec = ctx->pkey->pkey.ec; 132 133 if (!sig) { 134 *siglen = ECDSA_size(ec); 135 return 1; 136 } else if (*siglen < (size_t)ECDSA_size(ec)) { 137 OPENSSL_PUT_ERROR(EVP, pkey_ec_sign, EVP_R_BUFFER_TOO_SMALL); 138 return 0; 139 } 140 141 type = NID_sha1; 142 if (dctx->md) { 143 type = EVP_MD_type(dctx->md); 144 } 145 146 if (!ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec)) { 147 return 0; 148 } 149 *siglen = (size_t)sltmp; 150 return 1; 151} 152 153static int pkey_ec_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t siglen, 154 const uint8_t *tbs, size_t tbslen) { 155 int type; 156 EC_PKEY_CTX *dctx = ctx->data; 157 EC_KEY *ec = ctx->pkey->pkey.ec; 158 159 type = NID_sha1; 160 if (dctx->md) { 161 type = EVP_MD_type(dctx->md); 162 } 163 164 return ECDSA_verify(type, tbs, tbslen, sig, siglen, ec); 165} 166 167static int pkey_ec_derive(EVP_PKEY_CTX *ctx, uint8_t *key, 168 size_t *keylen) { 169 int ret; 170 size_t outlen; 171 const EC_POINT *pubkey = NULL; 172 EC_KEY *eckey; 173 174 if (!ctx->pkey || !ctx->peerkey) { 175 OPENSSL_PUT_ERROR(EVP, pkey_ec_derive, EVP_R_KEYS_NOT_SET); 176 return 0; 177 } 178 179 eckey = ctx->pkey->pkey.ec; 180 181 if (!key) { 182 const EC_GROUP *group; 183 group = EC_KEY_get0_group(eckey); 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 /* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is 190 * not an error, the result is truncated. */ 191 192 outlen = *keylen; 193 194 ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0); 195 if (ret < 0) { 196 return 0; 197 } 198 *keylen = ret; 199 return 1; 200} 201 202static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) { 203 EC_PKEY_CTX *dctx = ctx->data; 204 EC_GROUP *group; 205 206 switch (type) { 207 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID: 208 group = EC_GROUP_new_by_curve_name(p1); 209 if (group == NULL) { 210 OPENSSL_PUT_ERROR(EVP, pkey_ec_ctrl, EVP_R_INVALID_CURVE); 211 return 0; 212 } 213 EC_GROUP_free(dctx->gen_group); 214 dctx->gen_group = group; 215 return 1; 216 217 case EVP_PKEY_CTRL_MD: 218 if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 && 219 EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 && 220 EVP_MD_type((const EVP_MD *)p2) != NID_sha224 && 221 EVP_MD_type((const EVP_MD *)p2) != NID_sha256 && 222 EVP_MD_type((const EVP_MD *)p2) != NID_sha384 && 223 EVP_MD_type((const EVP_MD *)p2) != NID_sha512) { 224 OPENSSL_PUT_ERROR(EVP, pkey_ec_ctrl, EVP_R_INVALID_DIGEST_TYPE); 225 return 0; 226 } 227 dctx->md = p2; 228 return 1; 229 230 case EVP_PKEY_CTRL_GET_MD: 231 *(const EVP_MD **)p2 = dctx->md; 232 return 1; 233 234 case EVP_PKEY_CTRL_PEER_KEY: 235 /* Default behaviour is OK */ 236 case EVP_PKEY_CTRL_DIGESTINIT: 237 return 1; 238 239 default: 240 OPENSSL_PUT_ERROR(EVP, pkey_ec_ctrl, EVP_R_COMMAND_NOT_SUPPORTED); 241 return 0; 242 } 243} 244 245static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) { 246 EC_KEY *ec = NULL; 247 EC_PKEY_CTX *dctx = ctx->data; 248 int ret = 0; 249 250 if (dctx->gen_group == NULL) { 251 OPENSSL_PUT_ERROR(EVP, pkey_ec_paramgen, EVP_R_NO_PARAMETERS_SET); 252 return 0; 253 } 254 ec = EC_KEY_new(); 255 if (!ec) { 256 return 0; 257 } 258 ret = EC_KEY_set_group(ec, dctx->gen_group); 259 if (ret) { 260 EVP_PKEY_assign_EC_KEY(pkey, ec); 261 } else { 262 EC_KEY_free(ec); 263 } 264 return ret; 265} 266 267static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) { 268 EC_KEY *ec = NULL; 269 EC_PKEY_CTX *dctx = ctx->data; 270 if (ctx->pkey == NULL && dctx->gen_group == NULL) { 271 OPENSSL_PUT_ERROR(EVP, pkey_ec_keygen, EVP_R_NO_PARAMETERS_SET); 272 return 0; 273 } 274 ec = EC_KEY_new(); 275 if (!ec) { 276 return 0; 277 } 278 EVP_PKEY_assign_EC_KEY(pkey, ec); 279 if (ctx->pkey) { 280 /* Note: if error return, pkey is freed by parent routine */ 281 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) { 282 return 0; 283 } 284 } else { 285 if (!EC_KEY_set_group(ec, dctx->gen_group)) { 286 return 0; 287 } 288 } 289 return EC_KEY_generate_key(pkey->pkey.ec); 290} 291 292const EVP_PKEY_METHOD ec_pkey_meth = { 293 EVP_PKEY_EC, 0 /* flags */, pkey_ec_init, 294 pkey_ec_copy, pkey_ec_cleanup, 0 /* paramgen_init */, 295 pkey_ec_paramgen, 0 /* keygen_init */, pkey_ec_keygen, 296 0 /* sign_init */, pkey_ec_sign, 0 /* verify_init */, 297 pkey_ec_verify, 0 /* signctx_init */, 0 /* signctx */, 298 0 /* verifyctx_init */, 0 /* verifyctx */, 0 /* encrypt_init */, 299 0 /* encrypt */, 0 /* decrypt_init */, 0 /* decrypt */, 300 0 /* derive_init */, pkey_ec_derive, pkey_ec_ctrl, 301}; 302