| /* Originally written by Bodo Moeller for the OpenSSL project. |
| * ==================================================================== |
| * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. All advertising materials mentioning features or use of this |
| * software must display the following acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| * |
| * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| * endorse or promote products derived from this software without |
| * prior written permission. For written permission, please contact |
| * openssl-core@openssl.org. |
| * |
| * 5. Products derived from this software may not be called "OpenSSL" |
| * nor may "OpenSSL" appear in their names without prior written |
| * permission of the OpenSSL Project. |
| * |
| * 6. Redistributions of any form whatsoever must retain the following |
| * acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This product includes cryptographic software written by Eric Young |
| * (eay@cryptsoft.com). This product includes software written by Tim |
| * Hudson (tjh@cryptsoft.com). |
| * |
| */ |
| /* ==================================================================== |
| * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. |
| * |
| * Portions of the attached software ("Contribution") are developed by |
| * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. |
| * |
| * The Contribution is licensed pursuant to the OpenSSL open source |
| * license provided above. |
| * |
| * The elliptic curve binary polynomial software is originally written by |
| * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems |
| * Laboratories. */ |
| |
| #include <openssl/ec.h> |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <openssl/bn.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/nid.h> |
| |
| #include "internal.h" |
| #include "../../internal.h" |
| #include "../bn/internal.h" |
| #include "../delocate.h" |
| |
| |
| static void ec_point_free(EC_POINT *point, int free_group); |
| |
| static const uint8_t kP224Params[6 * 28] = { |
| // p |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
| 0x00, 0x00, 0x00, 0x01, |
| // a |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFE, |
| // b |
| 0xB4, 0x05, 0x0A, 0x85, 0x0C, 0x04, 0xB3, 0xAB, 0xF5, 0x41, 0x32, 0x56, |
| 0x50, 0x44, 0xB0, 0xB7, 0xD7, 0xBF, 0xD8, 0xBA, 0x27, 0x0B, 0x39, 0x43, |
| 0x23, 0x55, 0xFF, 0xB4, |
| // x |
| 0xB7, 0x0E, 0x0C, 0xBD, 0x6B, 0xB4, 0xBF, 0x7F, 0x32, 0x13, 0x90, 0xB9, |
| 0x4A, 0x03, 0xC1, 0xD3, 0x56, 0xC2, 0x11, 0x22, 0x34, 0x32, 0x80, 0xD6, |
| 0x11, 0x5C, 0x1D, 0x21, |
| // y |
| 0xbd, 0x37, 0x63, 0x88, 0xb5, 0xf7, 0x23, 0xfb, 0x4c, 0x22, 0xdf, 0xe6, |
| 0xcd, 0x43, 0x75, 0xa0, 0x5a, 0x07, 0x47, 0x64, 0x44, 0xd5, 0x81, 0x99, |
| 0x85, 0x00, 0x7e, 0x34, |
| // order |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0x16, 0xA2, 0xE0, 0xB8, 0xF0, 0x3E, 0x13, 0xDD, 0x29, 0x45, |
| 0x5C, 0x5C, 0x2A, 0x3D, |
| }; |
| |
| static const uint8_t kP256Params[6 * 32] = { |
| // p |
| 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| // a |
| 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, |
| // b |
| 0x5A, 0xC6, 0x35, 0xD8, 0xAA, 0x3A, 0x93, 0xE7, 0xB3, 0xEB, 0xBD, 0x55, |
| 0x76, 0x98, 0x86, 0xBC, 0x65, 0x1D, 0x06, 0xB0, 0xCC, 0x53, 0xB0, 0xF6, |
| 0x3B, 0xCE, 0x3C, 0x3E, 0x27, 0xD2, 0x60, 0x4B, |
| // x |
| 0x6B, 0x17, 0xD1, 0xF2, 0xE1, 0x2C, 0x42, 0x47, 0xF8, 0xBC, 0xE6, 0xE5, |
| 0x63, 0xA4, 0x40, 0xF2, 0x77, 0x03, 0x7D, 0x81, 0x2D, 0xEB, 0x33, 0xA0, |
| 0xF4, 0xA1, 0x39, 0x45, 0xD8, 0x98, 0xC2, 0x96, |
| // y |
| 0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, 0x8e, 0xe7, 0xeb, 0x4a, |
| 0x7c, 0x0f, 0x9e, 0x16, 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce, |
| 0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5, |
| // order |
| 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xBC, 0xE6, 0xFA, 0xAD, 0xA7, 0x17, 0x9E, 0x84, |
| 0xF3, 0xB9, 0xCA, 0xC2, 0xFC, 0x63, 0x25, 0x51, |
| }; |
| |
| static const uint8_t kP384Params[6 * 48] = { |
| // p |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, |
| // a |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFC, |
| // b |
| 0xB3, 0x31, 0x2F, 0xA7, 0xE2, 0x3E, 0xE7, 0xE4, 0x98, 0x8E, 0x05, 0x6B, |
| 0xE3, 0xF8, 0x2D, 0x19, 0x18, 0x1D, 0x9C, 0x6E, 0xFE, 0x81, 0x41, 0x12, |
| 0x03, 0x14, 0x08, 0x8F, 0x50, 0x13, 0x87, 0x5A, 0xC6, 0x56, 0x39, 0x8D, |
| 0x8A, 0x2E, 0xD1, 0x9D, 0x2A, 0x85, 0xC8, 0xED, 0xD3, 0xEC, 0x2A, 0xEF, |
| // x |
| 0xAA, 0x87, 0xCA, 0x22, 0xBE, 0x8B, 0x05, 0x37, 0x8E, 0xB1, 0xC7, 0x1E, |
| 0xF3, 0x20, 0xAD, 0x74, 0x6E, 0x1D, 0x3B, 0x62, 0x8B, 0xA7, 0x9B, 0x98, |
| 0x59, 0xF7, 0x41, 0xE0, 0x82, 0x54, 0x2A, 0x38, 0x55, 0x02, 0xF2, 0x5D, |
| 0xBF, 0x55, 0x29, 0x6C, 0x3A, 0x54, 0x5E, 0x38, 0x72, 0x76, 0x0A, 0xB7, |
| // y |
| 0x36, 0x17, 0xde, 0x4a, 0x96, 0x26, 0x2c, 0x6f, 0x5d, 0x9e, 0x98, 0xbf, |
| 0x92, 0x92, 0xdc, 0x29, 0xf8, 0xf4, 0x1d, 0xbd, 0x28, 0x9a, 0x14, 0x7c, |
| 0xe9, 0xda, 0x31, 0x13, 0xb5, 0xf0, 0xb8, 0xc0, 0x0a, 0x60, 0xb1, 0xce, |
| 0x1d, 0x7e, 0x81, 0x9d, 0x7a, 0x43, 0x1d, 0x7c, 0x90, 0xea, 0x0e, 0x5f, |
| // order |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xC7, 0x63, 0x4D, 0x81, 0xF4, 0x37, 0x2D, 0xDF, 0x58, 0x1A, 0x0D, 0xB2, |
| 0x48, 0xB0, 0xA7, 0x7A, 0xEC, 0xEC, 0x19, 0x6A, 0xCC, 0xC5, 0x29, 0x73, |
| }; |
| |
| static const uint8_t kP521Params[6 * 66] = { |
| // p |
| 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| // a |
| 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, |
| // b |
| 0x00, 0x51, 0x95, 0x3E, 0xB9, 0x61, 0x8E, 0x1C, 0x9A, 0x1F, 0x92, 0x9A, |
| 0x21, 0xA0, 0xB6, 0x85, 0x40, 0xEE, 0xA2, 0xDA, 0x72, 0x5B, 0x99, 0xB3, |
| 0x15, 0xF3, 0xB8, 0xB4, 0x89, 0x91, 0x8E, 0xF1, 0x09, 0xE1, 0x56, 0x19, |
| 0x39, 0x51, 0xEC, 0x7E, 0x93, 0x7B, 0x16, 0x52, 0xC0, 0xBD, 0x3B, 0xB1, |
| 0xBF, 0x07, 0x35, 0x73, 0xDF, 0x88, 0x3D, 0x2C, 0x34, 0xF1, 0xEF, 0x45, |
| 0x1F, 0xD4, 0x6B, 0x50, 0x3F, 0x00, |
| // x |
| 0x00, 0xC6, 0x85, 0x8E, 0x06, 0xB7, 0x04, 0x04, 0xE9, 0xCD, 0x9E, 0x3E, |
| 0xCB, 0x66, 0x23, 0x95, 0xB4, 0x42, 0x9C, 0x64, 0x81, 0x39, 0x05, 0x3F, |
| 0xB5, 0x21, 0xF8, 0x28, 0xAF, 0x60, 0x6B, 0x4D, 0x3D, 0xBA, 0xA1, 0x4B, |
| 0x5E, 0x77, 0xEF, 0xE7, 0x59, 0x28, 0xFE, 0x1D, 0xC1, 0x27, 0xA2, 0xFF, |
| 0xA8, 0xDE, 0x33, 0x48, 0xB3, 0xC1, 0x85, 0x6A, 0x42, 0x9B, 0xF9, 0x7E, |
| 0x7E, 0x31, 0xC2, 0xE5, 0xBD, 0x66, |
| // y |
| 0x01, 0x18, 0x39, 0x29, 0x6a, 0x78, 0x9a, 0x3b, 0xc0, 0x04, 0x5c, 0x8a, |
| 0x5f, 0xb4, 0x2c, 0x7d, 0x1b, 0xd9, 0x98, 0xf5, 0x44, 0x49, 0x57, 0x9b, |
| 0x44, 0x68, 0x17, 0xaf, 0xbd, 0x17, 0x27, 0x3e, 0x66, 0x2c, 0x97, 0xee, |
| 0x72, 0x99, 0x5e, 0xf4, 0x26, 0x40, 0xc5, 0x50, 0xb9, 0x01, 0x3f, 0xad, |
| 0x07, 0x61, 0x35, 0x3c, 0x70, 0x86, 0xa2, 0x72, 0xc2, 0x40, 0x88, 0xbe, |
| 0x94, 0x76, 0x9f, 0xd1, 0x66, 0x50, |
| // order |
| 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
| 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFA, 0x51, 0x86, |
| 0x87, 0x83, 0xBF, 0x2F, 0x96, 0x6B, 0x7F, 0xCC, 0x01, 0x48, 0xF7, 0x09, |
| 0xA5, 0xD0, 0x3B, 0xB5, 0xC9, 0xB8, 0x89, 0x9C, 0x47, 0xAE, 0xBB, 0x6F, |
| 0xB7, 0x1E, 0x91, 0x38, 0x64, 0x09, |
| }; |
| |
| DEFINE_METHOD_FUNCTION(struct built_in_curves, OPENSSL_built_in_curves) { |
| // 1.3.132.0.35 |
| static const uint8_t kOIDP521[] = {0x2b, 0x81, 0x04, 0x00, 0x23}; |
| out->curves[0].nid = NID_secp521r1; |
| out->curves[0].oid = kOIDP521; |
| out->curves[0].oid_len = sizeof(kOIDP521); |
| out->curves[0].comment = "NIST P-521"; |
| out->curves[0].param_len = 66; |
| out->curves[0].params = kP521Params; |
| out->curves[0].method = EC_GFp_mont_method(); |
| |
| // 1.3.132.0.34 |
| static const uint8_t kOIDP384[] = {0x2b, 0x81, 0x04, 0x00, 0x22}; |
| out->curves[1].nid = NID_secp384r1; |
| out->curves[1].oid = kOIDP384; |
| out->curves[1].oid_len = sizeof(kOIDP384); |
| out->curves[1].comment = "NIST P-384"; |
| out->curves[1].param_len = 48; |
| out->curves[1].params = kP384Params; |
| out->curves[1].method = EC_GFp_mont_method(); |
| |
| // 1.2.840.10045.3.1.7 |
| static const uint8_t kOIDP256[] = {0x2a, 0x86, 0x48, 0xce, |
| 0x3d, 0x03, 0x01, 0x07}; |
| out->curves[2].nid = NID_X9_62_prime256v1; |
| out->curves[2].oid = kOIDP256; |
| out->curves[2].oid_len = sizeof(kOIDP256); |
| out->curves[2].comment = "NIST P-256"; |
| out->curves[2].param_len = 32; |
| out->curves[2].params = kP256Params; |
| out->curves[2].method = |
| #if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) && \ |
| !defined(OPENSSL_SMALL) |
| EC_GFp_nistz256_method(); |
| #else |
| EC_GFp_nistp256_method(); |
| #endif |
| |
| // 1.3.132.0.33 |
| static const uint8_t kOIDP224[] = {0x2b, 0x81, 0x04, 0x00, 0x21}; |
| out->curves[3].nid = NID_secp224r1; |
| out->curves[3].oid = kOIDP224; |
| out->curves[3].oid_len = sizeof(kOIDP224); |
| out->curves[3].comment = "NIST P-224"; |
| out->curves[3].param_len = 28; |
| out->curves[3].params = kP224Params; |
| out->curves[3].method = |
| #if defined(BORINGSSL_HAS_UINT128) && !defined(OPENSSL_SMALL) |
| EC_GFp_nistp224_method(); |
| #else |
| EC_GFp_mont_method(); |
| #endif |
| } |
| |
| EC_GROUP *ec_group_new(const EC_METHOD *meth) { |
| EC_GROUP *ret; |
| |
| if (meth == NULL) { |
| OPENSSL_PUT_ERROR(EC, EC_R_SLOT_FULL); |
| return NULL; |
| } |
| |
| if (meth->group_init == 0) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| return NULL; |
| } |
| |
| ret = OPENSSL_malloc(sizeof(EC_GROUP)); |
| if (ret == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| OPENSSL_memset(ret, 0, sizeof(EC_GROUP)); |
| |
| ret->references = 1; |
| ret->meth = meth; |
| BN_init(&ret->order); |
| |
| if (!meth->group_init(ret)) { |
| OPENSSL_free(ret); |
| return NULL; |
| } |
| |
| return ret; |
| } |
| |
| static void ec_group_set0_generator(EC_GROUP *group, EC_POINT *generator) { |
| assert(group->generator == NULL); |
| assert(group == generator->group); |
| |
| // Avoid a reference cycle. |group->generator| does not maintain an owning |
| // pointer to |group|. |
| group->generator = generator; |
| int is_zero = CRYPTO_refcount_dec_and_test_zero(&group->references); |
| |
| assert(!is_zero); |
| (void)is_zero; |
| } |
| |
| EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a, |
| const BIGNUM *b, BN_CTX *ctx) { |
| if (BN_num_bytes(p) > EC_MAX_BYTES) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INVALID_FIELD); |
| return NULL; |
| } |
| |
| EC_GROUP *ret = ec_group_new(EC_GFp_mont_method()); |
| if (ret == NULL) { |
| return NULL; |
| } |
| |
| if (ret->meth->group_set_curve == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| EC_GROUP_free(ret); |
| return NULL; |
| } |
| if (!ret->meth->group_set_curve(ret, p, a, b, ctx)) { |
| EC_GROUP_free(ret); |
| return NULL; |
| } |
| return ret; |
| } |
| |
| int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, |
| const BIGNUM *order, const BIGNUM *cofactor) { |
| if (group->curve_name != NID_undef || group->generator != NULL || |
| generator->group != group) { |
| // |EC_GROUP_set_generator| may only be used with |EC_GROUP|s returned by |
| // |EC_GROUP_new_curve_GFp| and may only used once on each group. |
| // |generator| must have been created from |EC_GROUP_new_curve_GFp|, not a |
| // copy, so that |generator->group->generator| is set correctly. |
| OPENSSL_PUT_ERROR(EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| return 0; |
| } |
| |
| if (BN_num_bytes(order) > EC_MAX_BYTES) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER); |
| return 0; |
| } |
| |
| // Require a cofactor of one for custom curves, which implies prime order. |
| if (!BN_is_one(cofactor)) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INVALID_COFACTOR); |
| return 0; |
| } |
| |
| // Require that p < 2×order. This simplifies some ECDSA operations. |
| // |
| // Note any curve which did not satisfy this must have been invalid or use a |
| // tiny prime (less than 17). See the proof in |field_element_to_scalar| in |
| // the ECDSA implementation. |
| int ret = 0; |
| EC_POINT *copy = NULL; |
| BIGNUM *tmp = BN_new(); |
| if (tmp == NULL || |
| !BN_lshift1(tmp, order)) { |
| goto err; |
| } |
| if (BN_cmp(tmp, &group->field) <= 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER); |
| goto err; |
| } |
| |
| copy = EC_POINT_new(group); |
| if (copy == NULL || |
| !EC_POINT_copy(copy, generator) || |
| !BN_copy(&group->order, order)) { |
| goto err; |
| } |
| // Store the order in minimal form, so it can be used with |BN_ULONG| arrays. |
| bn_set_minimal_width(&group->order); |
| |
| BN_MONT_CTX_free(group->order_mont); |
| group->order_mont = BN_MONT_CTX_new_for_modulus(&group->order, NULL); |
| if (group->order_mont == NULL) { |
| goto err; |
| } |
| |
| group->field_greater_than_order = BN_cmp(&group->field, &group->order) > 0; |
| if (group->field_greater_than_order) { |
| if (!BN_sub(tmp, &group->field, &group->order) || |
| !bn_copy_words(group->field_minus_order.words, group->field.width, |
| tmp)) { |
| goto err; |
| } |
| } |
| |
| ec_group_set0_generator(group, copy); |
| copy = NULL; |
| ret = 1; |
| |
| err: |
| EC_POINT_free(copy); |
| BN_free(tmp); |
| return ret; |
| } |
| |
| static EC_GROUP *ec_group_new_from_data(const struct built_in_curve *curve) { |
| EC_GROUP *group = NULL; |
| EC_POINT *P = NULL; |
| BIGNUM *p = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL; |
| int ok = 0; |
| |
| BN_CTX *ctx = BN_CTX_new(); |
| if (ctx == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| const unsigned param_len = curve->param_len; |
| const uint8_t *params = curve->params; |
| |
| if (!(p = BN_bin2bn(params + 0 * param_len, param_len, NULL)) || |
| !(a = BN_bin2bn(params + 1 * param_len, param_len, NULL)) || |
| !(b = BN_bin2bn(params + 2 * param_len, param_len, NULL))) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB); |
| goto err; |
| } |
| |
| group = ec_group_new(curve->method); |
| if (group == NULL || |
| !group->meth->group_set_curve(group, p, a, b, ctx)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB); |
| goto err; |
| } |
| |
| if ((P = EC_POINT_new(group)) == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB); |
| goto err; |
| } |
| |
| if (!(x = BN_bin2bn(params + 3 * param_len, param_len, NULL)) || |
| !(y = BN_bin2bn(params + 4 * param_len, param_len, NULL))) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB); |
| goto err; |
| } |
| |
| if (!EC_POINT_set_affine_coordinates_GFp(group, P, x, y, ctx)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB); |
| goto err; |
| } |
| if (!BN_bin2bn(params + 5 * param_len, param_len, &group->order)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB); |
| goto err; |
| } |
| |
| group->field_greater_than_order = BN_cmp(&group->field, &group->order) > 0; |
| if (group->field_greater_than_order) { |
| if (!BN_sub(p, &group->field, &group->order) || |
| !bn_copy_words(group->field_minus_order.words, group->field.width, p)) { |
| goto err; |
| } |
| } |
| |
| group->order_mont = BN_MONT_CTX_new_for_modulus(&group->order, ctx); |
| if (group->order_mont == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB); |
| goto err; |
| } |
| |
| ec_group_set0_generator(group, P); |
| P = NULL; |
| ok = 1; |
| |
| err: |
| if (!ok) { |
| EC_GROUP_free(group); |
| group = NULL; |
| } |
| EC_POINT_free(P); |
| BN_CTX_free(ctx); |
| BN_free(p); |
| BN_free(a); |
| BN_free(b); |
| BN_free(x); |
| BN_free(y); |
| return group; |
| } |
| |
| // Built-in groups are allocated lazily and static once allocated. |
| // TODO(davidben): Make these actually static. https://crbug.com/boringssl/20. |
| struct built_in_groups_st { |
| EC_GROUP *groups[OPENSSL_NUM_BUILT_IN_CURVES]; |
| }; |
| DEFINE_BSS_GET(struct built_in_groups_st, built_in_groups); |
| DEFINE_STATIC_MUTEX(built_in_groups_lock); |
| |
| EC_GROUP *EC_GROUP_new_by_curve_name(int nid) { |
| struct built_in_groups_st *groups = built_in_groups_bss_get(); |
| EC_GROUP **group_ptr = NULL; |
| const struct built_in_curves *const curves = OPENSSL_built_in_curves(); |
| const struct built_in_curve *curve = NULL; |
| for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) { |
| if (curves->curves[i].nid == nid) { |
| curve = &curves->curves[i]; |
| group_ptr = &groups->groups[i]; |
| break; |
| } |
| } |
| |
| if (curve == NULL) { |
| OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP); |
| return NULL; |
| } |
| |
| CRYPTO_STATIC_MUTEX_lock_read(built_in_groups_lock_bss_get()); |
| EC_GROUP *ret = *group_ptr; |
| CRYPTO_STATIC_MUTEX_unlock_read(built_in_groups_lock_bss_get()); |
| if (ret != NULL) { |
| return ret; |
| } |
| |
| ret = ec_group_new_from_data(curve); |
| if (ret == NULL) { |
| return NULL; |
| } |
| |
| EC_GROUP *to_free = NULL; |
| CRYPTO_STATIC_MUTEX_lock_write(built_in_groups_lock_bss_get()); |
| if (*group_ptr == NULL) { |
| *group_ptr = ret; |
| // Filling in |ret->curve_name| makes |EC_GROUP_free| and |EC_GROUP_dup| |
| // into no-ops. At this point, |ret| is considered static. |
| ret->curve_name = nid; |
| } else { |
| to_free = ret; |
| ret = *group_ptr; |
| } |
| CRYPTO_STATIC_MUTEX_unlock_write(built_in_groups_lock_bss_get()); |
| |
| EC_GROUP_free(to_free); |
| return ret; |
| } |
| |
| void EC_GROUP_free(EC_GROUP *group) { |
| if (group == NULL || |
| // Built-in curves are static. |
| group->curve_name != NID_undef || |
| !CRYPTO_refcount_dec_and_test_zero(&group->references)) { |
| return; |
| } |
| |
| if (group->meth->group_finish != NULL) { |
| group->meth->group_finish(group); |
| } |
| |
| ec_point_free(group->generator, 0 /* don't free group */); |
| BN_free(&group->order); |
| BN_MONT_CTX_free(group->order_mont); |
| |
| OPENSSL_free(group); |
| } |
| |
| EC_GROUP *EC_GROUP_dup(const EC_GROUP *a) { |
| if (a == NULL || |
| // Built-in curves are static. |
| a->curve_name != NID_undef) { |
| return (EC_GROUP *)a; |
| } |
| |
| // Groups are logically immutable (but for |EC_GROUP_set_generator| which must |
| // be called early on), so we simply take a reference. |
| EC_GROUP *group = (EC_GROUP *)a; |
| CRYPTO_refcount_inc(&group->references); |
| return group; |
| } |
| |
| int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ignored) { |
| // Note this function returns 0 if equal and non-zero otherwise. |
| if (a == b) { |
| return 0; |
| } |
| if (a->curve_name != b->curve_name) { |
| return 1; |
| } |
| if (a->curve_name != NID_undef) { |
| // Built-in curves may be compared by curve name alone. |
| return 0; |
| } |
| |
| // |a| and |b| are both custom curves. We compare the entire curve |
| // structure. If |a| or |b| is incomplete (due to legacy OpenSSL mistakes, |
| // custom curve construction is sadly done in two parts) but otherwise not the |
| // same object, we consider them always unequal. |
| return a->meth != b->meth || |
| a->generator == NULL || |
| b->generator == NULL || |
| BN_cmp(&a->order, &b->order) != 0 || |
| BN_cmp(&a->field, &b->field) != 0 || |
| !ec_felem_equal(a, &a->a, &b->a) || |
| !ec_felem_equal(a, &a->b, &b->b) || |
| ec_GFp_simple_cmp(a, &a->generator->raw, &b->generator->raw) != 0; |
| } |
| |
| const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group) { |
| return group->generator; |
| } |
| |
| const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group) { |
| assert(!BN_is_zero(&group->order)); |
| return &group->order; |
| } |
| |
| int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx) { |
| if (BN_copy(order, EC_GROUP_get0_order(group)) == NULL) { |
| return 0; |
| } |
| return 1; |
| } |
| |
| int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, |
| BN_CTX *ctx) { |
| // All |EC_GROUP|s have cofactor 1. |
| return BN_set_word(cofactor, 1); |
| } |
| |
| int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *out_p, BIGNUM *out_a, |
| BIGNUM *out_b, BN_CTX *ctx) { |
| return ec_GFp_simple_group_get_curve(group, out_p, out_a, out_b); |
| } |
| |
| int EC_GROUP_get_curve_name(const EC_GROUP *group) { return group->curve_name; } |
| |
| unsigned EC_GROUP_get_degree(const EC_GROUP *group) { |
| return BN_num_bits(&group->field); |
| } |
| |
| const char *EC_curve_nid2nist(int nid) { |
| switch (nid) { |
| case NID_secp224r1: |
| return "P-224"; |
| case NID_X9_62_prime256v1: |
| return "P-256"; |
| case NID_secp384r1: |
| return "P-384"; |
| case NID_secp521r1: |
| return "P-521"; |
| } |
| return NULL; |
| } |
| |
| EC_POINT *EC_POINT_new(const EC_GROUP *group) { |
| if (group == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); |
| return NULL; |
| } |
| |
| EC_POINT *ret = OPENSSL_malloc(sizeof *ret); |
| if (ret == NULL) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| ret->group = EC_GROUP_dup(group); |
| ec_GFp_simple_point_init(&ret->raw); |
| return ret; |
| } |
| |
| static void ec_point_free(EC_POINT *point, int free_group) { |
| if (!point) { |
| return; |
| } |
| if (free_group) { |
| EC_GROUP_free(point->group); |
| } |
| OPENSSL_free(point); |
| } |
| |
| void EC_POINT_free(EC_POINT *point) { |
| ec_point_free(point, 1 /* free group */); |
| } |
| |
| void EC_POINT_clear_free(EC_POINT *point) { EC_POINT_free(point); } |
| |
| int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src) { |
| if (EC_GROUP_cmp(dest->group, src->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| if (dest == src) { |
| return 1; |
| } |
| ec_GFp_simple_point_copy(&dest->raw, &src->raw); |
| return 1; |
| } |
| |
| EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group) { |
| if (a == NULL) { |
| return NULL; |
| } |
| |
| EC_POINT *ret = EC_POINT_new(group); |
| if (ret == NULL || |
| !EC_POINT_copy(ret, a)) { |
| EC_POINT_free(ret); |
| return NULL; |
| } |
| |
| return ret; |
| } |
| |
| int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point) { |
| if (EC_GROUP_cmp(group, point->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| ec_GFp_simple_point_set_to_infinity(group, &point->raw); |
| return 1; |
| } |
| |
| int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point) { |
| if (EC_GROUP_cmp(group, point->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| return ec_GFp_simple_is_at_infinity(group, &point->raw); |
| } |
| |
| int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point, |
| BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, point->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| return ec_GFp_simple_is_on_curve(group, &point->raw); |
| } |
| |
| int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, |
| BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, a->group, NULL) != 0 || |
| EC_GROUP_cmp(group, b->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return -1; |
| } |
| return ec_GFp_simple_cmp(group, &a->raw, &b->raw); |
| } |
| |
| int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, |
| const EC_POINT *point, BIGNUM *x, |
| BIGNUM *y, BN_CTX *ctx) { |
| if (group->meth->point_get_affine_coordinates == 0) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| return 0; |
| } |
| if (EC_GROUP_cmp(group, point->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| EC_FELEM x_felem, y_felem; |
| if (!group->meth->point_get_affine_coordinates(group, &point->raw, |
| x == NULL ? NULL : &x_felem, |
| y == NULL ? NULL : &y_felem) || |
| (x != NULL && !bn_set_words(x, x_felem.words, group->field.width)) || |
| (y != NULL && !bn_set_words(y, y_felem.words, group->field.width))) { |
| return 0; |
| } |
| return 1; |
| } |
| |
| int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point, |
| const BIGNUM *x, const BIGNUM *y, |
| BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, point->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| if (!ec_GFp_simple_point_set_affine_coordinates(group, &point->raw, x, y)) { |
| return 0; |
| } |
| |
| if (!EC_POINT_is_on_curve(group, point, ctx)) { |
| // In the event of an error, defend against the caller not checking the |
| // return value by setting a known safe value: the base point. |
| const EC_POINT *generator = EC_GROUP_get0_generator(group); |
| // The generator can be missing if the caller is in the process of |
| // constructing an arbitrary group. In this, we give up and hope they're |
| // checking the return value. |
| if (generator) { |
| ec_GFp_simple_point_copy(&point->raw, &generator->raw); |
| } |
| OPENSSL_PUT_ERROR(EC, EC_R_POINT_IS_NOT_ON_CURVE); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, |
| const EC_POINT *b, BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, r->group, NULL) != 0 || |
| EC_GROUP_cmp(group, a->group, NULL) != 0 || |
| EC_GROUP_cmp(group, b->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| group->meth->add(group, &r->raw, &a->raw, &b->raw); |
| return 1; |
| } |
| |
| int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, |
| BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, r->group, NULL) != 0 || |
| EC_GROUP_cmp(group, a->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| group->meth->dbl(group, &r->raw, &a->raw); |
| return 1; |
| } |
| |
| |
| int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx) { |
| if (EC_GROUP_cmp(group, a->group, NULL) != 0) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| ec_GFp_simple_invert(group, &a->raw); |
| return 1; |
| } |
| |
| static int arbitrary_bignum_to_scalar(const EC_GROUP *group, EC_SCALAR *out, |
| const BIGNUM *in, BN_CTX *ctx) { |
| if (ec_bignum_to_scalar(group, out, in)) { |
| return 1; |
| } |
| |
| ERR_clear_error(); |
| |
| // This is an unusual input, so we do not guarantee constant-time processing. |
| const BIGNUM *order = &group->order; |
| BN_CTX_start(ctx); |
| BIGNUM *tmp = BN_CTX_get(ctx); |
| int ok = tmp != NULL && |
| BN_nnmod(tmp, in, order, ctx) && |
| ec_bignum_to_scalar(group, out, tmp); |
| BN_CTX_end(ctx); |
| return ok; |
| } |
| |
| int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar, |
| const EC_POINT *p, const BIGNUM *p_scalar, BN_CTX *ctx) { |
| // Previously, this function set |r| to the point at infinity if there was |
| // nothing to multiply. But, nobody should be calling this function with |
| // nothing to multiply in the first place. |
| if ((g_scalar == NULL && p_scalar == NULL) || |
| (p == NULL) != (p_scalar == NULL)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); |
| return 0; |
| } |
| |
| if (EC_GROUP_cmp(group, r->group, NULL) != 0 || |
| (p != NULL && EC_GROUP_cmp(group, p->group, NULL) != 0)) { |
| OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS); |
| return 0; |
| } |
| |
| int ret = 0; |
| EC_SCALAR g_scalar_storage, p_scalar_storage; |
| EC_SCALAR *g_scalar_arg = NULL, *p_scalar_arg = NULL; |
| BN_CTX *new_ctx = NULL; |
| if (ctx == NULL) { |
| new_ctx = BN_CTX_new(); |
| if (new_ctx == NULL) { |
| goto err; |
| } |
| ctx = new_ctx; |
| } |
| |
| if (g_scalar != NULL) { |
| if (!arbitrary_bignum_to_scalar(group, &g_scalar_storage, g_scalar, ctx)) { |
| goto err; |
| } |
| g_scalar_arg = &g_scalar_storage; |
| } |
| |
| if (p_scalar != NULL) { |
| if (!arbitrary_bignum_to_scalar(group, &p_scalar_storage, p_scalar, ctx)) { |
| goto err; |
| } |
| p_scalar_arg = &p_scalar_storage; |
| } |
| |
| ret = ec_point_mul_scalar(group, &r->raw, g_scalar_arg, |
| p == NULL ? NULL : &p->raw, p_scalar_arg); |
| |
| err: |
| BN_CTX_free(new_ctx); |
| OPENSSL_cleanse(&g_scalar_storage, sizeof(g_scalar_storage)); |
| OPENSSL_cleanse(&p_scalar_storage, sizeof(p_scalar_storage)); |
| return ret; |
| } |
| |
| int ec_point_mul_scalar_public(const EC_GROUP *group, EC_RAW_POINT *r, |
| const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, |
| const EC_SCALAR *p_scalar) { |
| if ((g_scalar == NULL && p_scalar == NULL) || |
| (p == NULL) != (p_scalar == NULL)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); |
| return 0; |
| } |
| |
| group->meth->mul_public(group, r, g_scalar, p, p_scalar); |
| return 1; |
| } |
| |
| int ec_point_mul_scalar(const EC_GROUP *group, EC_RAW_POINT *r, |
| const EC_SCALAR *g_scalar, const EC_RAW_POINT *p, |
| const EC_SCALAR *p_scalar) { |
| if ((g_scalar == NULL && p_scalar == NULL) || |
| (p == NULL) != (p_scalar == NULL)) { |
| OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); |
| return 0; |
| } |
| |
| group->meth->mul(group, r, g_scalar, p, p_scalar); |
| return 1; |
| } |
| |
| int ec_cmp_x_coordinate(const EC_GROUP *group, const EC_RAW_POINT *p, |
| const EC_SCALAR *r) { |
| return group->meth->cmp_x_coordinate(group, p, r); |
| } |
| |
| int ec_get_x_coordinate_as_scalar(const EC_GROUP *group, EC_SCALAR *out, |
| const EC_RAW_POINT *p) { |
| EC_FELEM x; |
| // For simplicity, in case of width mismatches between |group->field| and |
| // |group->order|, zero any untouched words in |x|. |
| OPENSSL_memset(&x, 0, sizeof(x)); |
| if (!group->meth->point_get_affine_coordinates(group, p, &x, NULL)) { |
| return 0; |
| } |
| |
| // We must have p < 2×order, assuming p is not tiny (p >= 17). Thus rather we |
| // can reduce by performing at most one subtraction. |
| // |
| // Proof: We only work with prime order curves, so the number of points on |
| // the curve is the order. Thus Hasse's theorem gives: |
| // |
| // |order - (p + 1)| <= 2×sqrt(p) |
| // p + 1 - order <= 2×sqrt(p) |
| // p + 1 - 2×sqrt(p) <= order |
| // p + 1 - 2×(p/4) < order (p/4 > sqrt(p) for p >= 17) |
| // p/2 < p/2 + 1 < order |
| // p < 2×order |
| // |
| // Additionally, one can manually check this property for built-in curves. It |
| // is enforced for legacy custom curves in |EC_GROUP_set_generator|. |
| |
| // The above does not guarantee |group->field| is not one word larger than |
| // |group->order|, so read one extra carry word. |
| BN_ULONG carry = |
| group->order.width < EC_MAX_WORDS ? x.words[group->order.width] : 0; |
| bn_reduce_once(out->words, x.words, carry, group->order.d, |
| group->order.width); |
| return 1; |
| } |
| |
| int ec_point_get_affine_coordinate_bytes(const EC_GROUP *group, uint8_t *out_x, |
| uint8_t *out_y, size_t *out_len, |
| size_t max_out, |
| const EC_RAW_POINT *p) { |
| size_t len = BN_num_bytes(&group->field); |
| assert(len <= EC_MAX_BYTES); |
| if (max_out < len) { |
| OPENSSL_PUT_ERROR(EC, EC_R_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| EC_FELEM x, y; |
| if (!group->meth->point_get_affine_coordinates( |
| group, p, out_x == NULL ? NULL : &x, out_y == NULL ? NULL : &y)) { |
| return 0; |
| } |
| |
| if (out_x != NULL) { |
| for (size_t i = 0; i < len; i++) { |
| out_x[i] = x.bytes[len - i - 1]; |
| } |
| } |
| if (out_y != NULL) { |
| for (size_t i = 0; i < len; i++) { |
| out_y[i] = y.bytes[len - i - 1]; |
| } |
| } |
| *out_len = len; |
| return 1; |
| } |
| |
| void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag) {} |
| |
| const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group) { |
| // This function exists purely to give callers a way to call |
| // |EC_METHOD_get_field_type|. cryptography.io crashes if |EC_GROUP_method_of| |
| // returns NULL, so return some other garbage pointer. |
| return (const EC_METHOD *)0x12340000; |
| } |
| |
| int EC_METHOD_get_field_type(const EC_METHOD *meth) { |
| return NID_X9_62_prime_field; |
| } |
| |
| void EC_GROUP_set_point_conversion_form(EC_GROUP *group, |
| point_conversion_form_t form) { |
| if (form != POINT_CONVERSION_UNCOMPRESSED) { |
| abort(); |
| } |
| } |
| |
| size_t EC_get_builtin_curves(EC_builtin_curve *out_curves, |
| size_t max_num_curves) { |
| const struct built_in_curves *const curves = OPENSSL_built_in_curves(); |
| |
| for (size_t i = 0; i < max_num_curves && i < OPENSSL_NUM_BUILT_IN_CURVES; |
| i++) { |
| out_curves[i].comment = curves->curves[i].comment; |
| out_curves[i].nid = curves->curves[i].nid; |
| } |
| |
| return OPENSSL_NUM_BUILT_IN_CURVES; |
| } |