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 <openssl/bn.h> 59 #include <openssl/bytestring.h> 60 #include <openssl/ec.h> 61 #include <openssl/ec_key.h> 62 #include <openssl/ecdsa.h> 63 #include <openssl/err.h> 64 65 #include "internal.h" 66 67 68 static int eckey_pub_encode(CBB *out, const EVP_PKEY *key) { 69 const EC_KEY *ec_key = key->pkey.ec; 70 const EC_GROUP *group = EC_KEY_get0_group(ec_key); 71 const EC_POINT *public_key = EC_KEY_get0_public_key(ec_key); 72 73 // See RFC 5480, section 2. 74 CBB spki, algorithm, oid, key_bitstring; 75 if (!CBB_add_asn1(out, &spki, CBS_ASN1_SEQUENCE) || 76 !CBB_add_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) || 77 !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) || 78 !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) || 79 !EC_KEY_marshal_curve_name(&algorithm, group) || 80 !CBB_add_asn1(&spki, &key_bitstring, CBS_ASN1_BITSTRING) || 81 !CBB_add_u8(&key_bitstring, 0 /* padding */) || 82 !EC_POINT_point2cbb(&key_bitstring, group, public_key, 83 POINT_CONVERSION_UNCOMPRESSED, NULL) || 84 !CBB_flush(out)) { 85 OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR); 86 return 0; 87 } 88 89 return 1; 90 } 91 92 static int eckey_pub_decode(EVP_PKEY *out, CBS *params, CBS *key) { 93 // See RFC 5480, section 2. 94 95 // The parameters are a named curve. 96 EC_POINT *point = NULL; 97 EC_KEY *eckey = NULL; 98 EC_GROUP *group = EC_KEY_parse_curve_name(params); 99 if (group == NULL || CBS_len(params) != 0) { 100 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); 101 goto err; 102 } 103 104 eckey = EC_KEY_new(); 105 if (eckey == NULL || !EC_KEY_set_group(eckey, group)) { 106 goto err; 107 } 108 109 point = EC_POINT_new(group); 110 if (point == NULL || 111 !EC_POINT_oct2point(group, point, CBS_data(key), CBS_len(key), NULL) || 112 !EC_KEY_set_public_key(eckey, point)) { 113 goto err; 114 } 115 116 EC_GROUP_free(group); 117 EC_POINT_free(point); 118 EVP_PKEY_assign_EC_KEY(out, eckey); 119 return 1; 120 121 err: 122 EC_GROUP_free(group); 123 EC_POINT_free(point); 124 EC_KEY_free(eckey); 125 return 0; 126 } 127 128 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b) { 129 int r; 130 const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec); 131 const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec), 132 *pb = EC_KEY_get0_public_key(b->pkey.ec); 133 r = EC_POINT_cmp(group, pa, pb, NULL); 134 if (r == 0) { 135 return 1; 136 } else if (r == 1) { 137 return 0; 138 } else { 139 return -2; 140 } 141 } 142 143 static int eckey_priv_decode(EVP_PKEY *out, CBS *params, CBS *key) { 144 // See RFC 5915. 145 EC_GROUP *group = EC_KEY_parse_parameters(params); 146 if (group == NULL || CBS_len(params) != 0) { 147 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); 148 EC_GROUP_free(group); 149 return 0; 150 } 151 152 EC_KEY *ec_key = EC_KEY_parse_private_key(key, group); 153 EC_GROUP_free(group); 154 if (ec_key == NULL || CBS_len(key) != 0) { 155 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); 156 EC_KEY_free(ec_key); 157 return 0; 158 } 159 160 EVP_PKEY_assign_EC_KEY(out, ec_key); 161 return 1; 162 } 163 164 static int eckey_priv_encode(CBB *out, const EVP_PKEY *key) { 165 const EC_KEY *ec_key = key->pkey.ec; 166 167 // Omit the redundant copy of the curve name. This contradicts RFC 5915 but 168 // aligns with PKCS #11. SEC 1 only says they may be omitted if known by other 169 // means. Both OpenSSL and NSS omit the redundant parameters, so we omit them 170 // as well. 171 unsigned enc_flags = EC_KEY_get_enc_flags(ec_key) | EC_PKEY_NO_PARAMETERS; 172 173 // See RFC 5915. 174 CBB pkcs8, algorithm, oid, private_key; 175 if (!CBB_add_asn1(out, &pkcs8, CBS_ASN1_SEQUENCE) || 176 !CBB_add_asn1_uint64(&pkcs8, 0 /* version */) || 177 !CBB_add_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) || 178 !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) || 179 !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) || 180 !EC_KEY_marshal_curve_name(&algorithm, EC_KEY_get0_group(ec_key)) || 181 !CBB_add_asn1(&pkcs8, &private_key, CBS_ASN1_OCTETSTRING) || 182 !EC_KEY_marshal_private_key(&private_key, ec_key, enc_flags) || 183 !CBB_flush(out)) { 184 OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR); 185 return 0; 186 } 187 188 return 1; 189 } 190 191 static int int_ec_size(const EVP_PKEY *pkey) { 192 return ECDSA_size(pkey->pkey.ec); 193 } 194 195 static int ec_bits(const EVP_PKEY *pkey) { 196 const EC_GROUP *group = EC_KEY_get0_group(pkey->pkey.ec); 197 if (group == NULL) { 198 ERR_clear_error(); 199 return 0; 200 } 201 return BN_num_bits(EC_GROUP_get0_order(group)); 202 } 203 204 static int ec_missing_parameters(const EVP_PKEY *pkey) { 205 return EC_KEY_get0_group(pkey->pkey.ec) == NULL; 206 } 207 208 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from) { 209 EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec)); 210 if (group == NULL || 211 EC_KEY_set_group(to->pkey.ec, group) == 0) { 212 return 0; 213 } 214 EC_GROUP_free(group); 215 return 1; 216 } 217 218 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b) { 219 const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec), 220 *group_b = EC_KEY_get0_group(b->pkey.ec); 221 if (EC_GROUP_cmp(group_a, group_b, NULL) != 0) { 222 // mismatch 223 return 0; 224 } 225 return 1; 226 } 227 228 static void int_ec_free(EVP_PKEY *pkey) { EC_KEY_free(pkey->pkey.ec); } 229 230 static int eckey_opaque(const EVP_PKEY *pkey) { 231 return EC_KEY_is_opaque(pkey->pkey.ec); 232 } 233 234 const EVP_PKEY_ASN1_METHOD ec_asn1_meth = { 235 EVP_PKEY_EC, 236 // 1.2.840.10045.2.1 237 {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01}, 7, 238 239 eckey_pub_decode, 240 eckey_pub_encode, 241 eckey_pub_cmp, 242 243 eckey_priv_decode, 244 eckey_priv_encode, 245 246 eckey_opaque, 247 248 int_ec_size, 249 ec_bits, 250 251 ec_missing_parameters, 252 ec_copy_parameters, 253 ec_cmp_parameters, 254 255 int_ec_free, 256 }; 257
