mirror of
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0e6dc84f3e
Also, change the way the standardized Diffie-Hellman groups are provided from macro-based string-literals to global variables.
725 lines
21 KiB
C
725 lines
21 KiB
C
/*
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* Diffie-Hellman-Merkle key exchange
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*
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* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of mbed TLS (https://tls.mbed.org)
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*/
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/*
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* The following sources were referenced in the design of this implementation
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* of the Diffie-Hellman-Merkle algorithm:
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*
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* [1] Handbook of Applied Cryptography - 1997, Chapter 12
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* Menezes, van Oorschot and Vanstone
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*
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*/
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#if !defined(MBEDTLS_CONFIG_FILE)
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#include "mbedtls/config.h"
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#else
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#include MBEDTLS_CONFIG_FILE
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#endif
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#if defined(MBEDTLS_DHM_C)
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#include "mbedtls/dhm.h"
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#include <string.h>
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#if defined(MBEDTLS_PEM_PARSE_C)
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#include "mbedtls/pem.h"
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#endif
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#if defined(MBEDTLS_ASN1_PARSE_C)
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#include "mbedtls/asn1.h"
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#endif
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#if defined(MBEDTLS_PLATFORM_C)
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#include "mbedtls/platform.h"
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#else
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#include <stdlib.h>
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#include <stdio.h>
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#define mbedtls_printf printf
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#define mbedtls_calloc calloc
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#define mbedtls_free free
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#endif
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/*
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* Diffie-Hellman groups from RFC 5114
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*
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* \warning The origin of the primes in RFC 5114 is not documented and
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* their use therefore constitutes a security risk!
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*
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* \deprecated The primes from RFC 5114 are superseded by the primes
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* from RFC 3526 and RFC 7919 and should no longer be used.
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* They will be removed in the next major version.
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*/
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const char * mbedtls_dhm_rfc5114_modp_2048_p =
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"AD107E1E9123A9D0D660FAA79559C51FA20D64E5683B9FD1"
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"B54B1597B61D0A75E6FA141DF95A56DBAF9A3C407BA1DF15"
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"EB3D688A309C180E1DE6B85A1274A0A66D3F8152AD6AC212"
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"9037C9EDEFDA4DF8D91E8FEF55B7394B7AD5B7D0B6C12207"
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"C9F98D11ED34DBF6C6BA0B2C8BBC27BE6A00E0A0B9C49708"
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"B3BF8A317091883681286130BC8985DB1602E714415D9330"
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"278273C7DE31EFDC7310F7121FD5A07415987D9ADC0A486D"
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"CDF93ACC44328387315D75E198C641A480CD86A1B9E587E8"
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"BE60E69CC928B2B9C52172E413042E9B23F10B0E16E79763"
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"C9B53DCF4BA80A29E3FB73C16B8E75B97EF363E2FFA31F71"
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"CF9DE5384E71B81C0AC4DFFE0C10E64F";
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const char * mbedtls_dhm_rfc5114_modp_2048_g =
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"AC4032EF4F2D9AE39DF30B5C8FFDAC506CDEBE7B89998CAF"
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"74866A08CFE4FFE3A6824A4E10B9A6F0DD921F01A70C4AFA"
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"AB739D7700C29F52C57DB17C620A8652BE5E9001A8D66AD7"
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"C17669101999024AF4D027275AC1348BB8A762D0521BC98A"
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"E247150422EA1ED409939D54DA7460CDB5F6C6B250717CBE"
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"F180EB34118E98D119529A45D6F834566E3025E316A330EF"
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"BB77A86F0C1AB15B051AE3D428C8F8ACB70A8137150B8EEB"
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"10E183EDD19963DDD9E263E4770589EF6AA21E7F5F2FF381"
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"B539CCE3409D13CD566AFBB48D6C019181E1BCFE94B30269"
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"EDFE72FE9B6AA4BD7B5A0F1C71CFFF4C19C418E1F6EC0179"
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"81BC087F2A7065B384B890D3191F2BFA";
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/*
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* Diffie-Hellman groups from RFC 3526
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*/
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const char * mbedtls_dhm_rfc3526_modp_2048_p =
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
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"29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
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"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
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"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
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"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
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"C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
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"83655D23DCA3AD961C62F356208552BB9ED529077096966D"
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"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
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"E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
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"DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
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"15728E5A8AACAA68FFFFFFFFFFFFFFFF";
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const char * mbedtls_dhm_rfc3526_modp_2048_g = "02";
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const char * mbedtls_dhm_rfc3526_modp_3072_p =
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
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"29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
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"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
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"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
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"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
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"C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
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"83655D23DCA3AD961C62F356208552BB9ED529077096966D"
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"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
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"E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
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"DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
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"15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64"
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"ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7"
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"ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B"
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"F12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
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"BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31"
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"43DB5BFCE0FD108E4B82D120A93AD2CAFFFFFFFFFFFFFFFF";
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const char * mbedtls_dhm_rfc3526_modp_3072_g = "02";
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const char * mbedtls_dhm_rfc3526_modp_4096_p =
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
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"29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
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"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
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"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
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"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
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"C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
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"83655D23DCA3AD961C62F356208552BB9ED529077096966D"
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"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
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"E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
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"DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
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"15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64"
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"ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7"
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"ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B"
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"F12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
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"BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31"
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"43DB5BFCE0FD108E4B82D120A92108011A723C12A787E6D7"
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"88719A10BDBA5B2699C327186AF4E23C1A946834B6150BDA"
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"2583E9CA2AD44CE8DBBBC2DB04DE8EF92E8EFC141FBECAA6"
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"287C59474E6BC05D99B2964FA090C3A2233BA186515BE7ED"
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"1F612970CEE2D7AFB81BDD762170481CD0069127D5B05AA9"
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"93B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934063199"
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"FFFFFFFFFFFFFFFF";
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const char * mbedtls_dhm_rfc3526_modp_4096_g = "02";
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/* Implementation that should never be optimized out by the compiler */
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static void mbedtls_zeroize( void *v, size_t n ) {
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volatile unsigned char *p = v; while( n-- ) *p++ = 0;
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}
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/*
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* helper to validate the mbedtls_mpi size and import it
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*/
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static int dhm_read_bignum( mbedtls_mpi *X,
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unsigned char **p,
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const unsigned char *end )
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{
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int ret, n;
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if( end - *p < 2 )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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n = ( (*p)[0] << 8 ) | (*p)[1];
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(*p) += 2;
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if( (int)( end - *p ) < n )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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if( ( ret = mbedtls_mpi_read_binary( X, *p, n ) ) != 0 )
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return( MBEDTLS_ERR_DHM_READ_PARAMS_FAILED + ret );
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(*p) += n;
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return( 0 );
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}
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/*
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* Verify sanity of parameter with regards to P
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*
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* Parameter should be: 2 <= public_param <= P - 2
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*
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* For more information on the attack, see:
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* http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
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* http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
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*/
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static int dhm_check_range( const mbedtls_mpi *param, const mbedtls_mpi *P )
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{
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mbedtls_mpi L, U;
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int ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
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mbedtls_mpi_init( &L ); mbedtls_mpi_init( &U );
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MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &L, 2 ) );
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MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &U, P, 2 ) );
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if( mbedtls_mpi_cmp_mpi( param, &L ) >= 0 &&
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mbedtls_mpi_cmp_mpi( param, &U ) <= 0 )
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{
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ret = 0;
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}
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cleanup:
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mbedtls_mpi_free( &L ); mbedtls_mpi_free( &U );
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return( ret );
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}
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void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
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{
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memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
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}
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/*
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* Parse the ServerKeyExchange parameters
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*/
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int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
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unsigned char **p,
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const unsigned char *end )
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{
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int ret;
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if( ( ret = dhm_read_bignum( &ctx->P, p, end ) ) != 0 ||
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( ret = dhm_read_bignum( &ctx->G, p, end ) ) != 0 ||
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( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
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return( ret );
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if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
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return( ret );
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ctx->len = mbedtls_mpi_size( &ctx->P );
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return( 0 );
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}
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/*
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* Setup and write the ServerKeyExchange parameters
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*/
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int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
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unsigned char *output, size_t *olen,
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int (*f_rng)(void *, unsigned char *, size_t),
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void *p_rng )
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{
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int ret, count = 0;
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size_t n1, n2, n3;
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unsigned char *p;
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if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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/*
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* Generate X as large as possible ( < P )
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*/
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do
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{
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MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ) );
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while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
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MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
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if( count++ > 10 )
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return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED );
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}
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while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
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/*
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* Calculate GX = G^X mod P
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*/
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MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
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&ctx->P , &ctx->RP ) );
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if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
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return( ret );
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/*
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* export P, G, GX
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*/
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#define DHM_MPI_EXPORT(X,n) \
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MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, p + 2, n ) ); \
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*p++ = (unsigned char)( n >> 8 ); \
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*p++ = (unsigned char)( n ); p += n;
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n1 = mbedtls_mpi_size( &ctx->P );
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n2 = mbedtls_mpi_size( &ctx->G );
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n3 = mbedtls_mpi_size( &ctx->GX );
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p = output;
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DHM_MPI_EXPORT( &ctx->P , n1 );
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DHM_MPI_EXPORT( &ctx->G , n2 );
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DHM_MPI_EXPORT( &ctx->GX, n3 );
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*olen = p - output;
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ctx->len = n1;
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cleanup:
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if( ret != 0 )
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return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED + ret );
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return( 0 );
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}
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/*
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* Import the peer's public value G^Y
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*/
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int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
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const unsigned char *input, size_t ilen )
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{
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int ret;
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if( ctx == NULL || ilen < 1 || ilen > ctx->len )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
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return( MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED + ret );
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return( 0 );
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}
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/*
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* Create own private value X and export G^X
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*/
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int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
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unsigned char *output, size_t olen,
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int (*f_rng)(void *, unsigned char *, size_t),
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void *p_rng )
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{
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int ret, count = 0;
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if( ctx == NULL || olen < 1 || olen > ctx->len )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
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return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
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/*
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* generate X and calculate GX = G^X mod P
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*/
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do
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{
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MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ) );
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while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
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MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
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if( count++ > 10 )
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return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED );
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}
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while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
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MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
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&ctx->P , &ctx->RP ) );
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if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
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return( ret );
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MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->GX, output, olen ) );
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cleanup:
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if( ret != 0 )
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return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED + ret );
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return( 0 );
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}
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/*
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* Use the blinding method and optimisation suggested in section 10 of:
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* KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
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* DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
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* Berlin Heidelberg, 1996. p. 104-113.
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*/
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static int dhm_update_blinding( mbedtls_dhm_context *ctx,
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int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
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{
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int ret, count;
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/*
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* Don't use any blinding the first time a particular X is used,
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* but remember it to use blinding next time.
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*/
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if( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->pX ) != 0 )
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{
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MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &ctx->pX, &ctx->X ) );
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MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vi, 1 ) );
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MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vf, 1 ) );
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|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Ok, we need blinding. Can we re-use existing values?
|
|
* If yes, just update them by squaring them.
|
|
*/
|
|
if( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* We need to generate blinding values from scratch
|
|
*/
|
|
|
|
/* Vi = random( 2, P-1 ) */
|
|
count = 0;
|
|
do
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vi, mbedtls_mpi_size( &ctx->P ), f_rng, p_rng ) );
|
|
|
|
while( mbedtls_mpi_cmp_mpi( &ctx->Vi, &ctx->P ) >= 0 )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->Vi, 1 ) );
|
|
|
|
if( count++ > 10 )
|
|
return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
|
|
}
|
|
while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) <= 0 );
|
|
|
|
/* Vf = Vi^-X mod P */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vf, &ctx->Vi, &ctx->P ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP ) );
|
|
|
|
cleanup:
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Derive and export the shared secret (G^Y)^X mod P
|
|
*/
|
|
int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
|
|
unsigned char *output, size_t output_size, size_t *olen,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret;
|
|
mbedtls_mpi GYb;
|
|
|
|
if( ctx == NULL || output_size < ctx->len )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_mpi_init( &GYb );
|
|
|
|
/* Blind peer's value */
|
|
if( f_rng != NULL )
|
|
{
|
|
MBEDTLS_MPI_CHK( dhm_update_blinding( ctx, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &GYb, &ctx->GY, &ctx->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &GYb, &GYb, &ctx->P ) );
|
|
}
|
|
else
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &GYb, &ctx->GY ) );
|
|
|
|
/* Do modular exponentiation */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->K, &GYb, &ctx->X,
|
|
&ctx->P, &ctx->RP ) );
|
|
|
|
/* Unblind secret value */
|
|
if( f_rng != NULL )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->K, &ctx->K, &ctx->Vf ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->K, &ctx->K, &ctx->P ) );
|
|
}
|
|
|
|
*olen = mbedtls_mpi_size( &ctx->K );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->K, output, *olen ) );
|
|
|
|
cleanup:
|
|
mbedtls_mpi_free( &GYb );
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_DHM_CALC_SECRET_FAILED + ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Free the components of a DHM key
|
|
*/
|
|
void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
|
|
{
|
|
mbedtls_mpi_free( &ctx->pX); mbedtls_mpi_free( &ctx->Vf ); mbedtls_mpi_free( &ctx->Vi );
|
|
mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->K ); mbedtls_mpi_free( &ctx->GY );
|
|
mbedtls_mpi_free( &ctx->GX ); mbedtls_mpi_free( &ctx->X ); mbedtls_mpi_free( &ctx->G );
|
|
mbedtls_mpi_free( &ctx->P );
|
|
|
|
mbedtls_zeroize( ctx, sizeof( mbedtls_dhm_context ) );
|
|
}
|
|
|
|
#if defined(MBEDTLS_ASN1_PARSE_C)
|
|
/*
|
|
* Parse DHM parameters
|
|
*/
|
|
int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
|
|
size_t dhminlen )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
unsigned char *p, *end;
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
mbedtls_pem_context pem;
|
|
|
|
mbedtls_pem_init( &pem );
|
|
|
|
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
|
|
if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' )
|
|
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
|
|
else
|
|
ret = mbedtls_pem_read_buffer( &pem,
|
|
"-----BEGIN DH PARAMETERS-----",
|
|
"-----END DH PARAMETERS-----",
|
|
dhmin, NULL, 0, &dhminlen );
|
|
|
|
if( ret == 0 )
|
|
{
|
|
/*
|
|
* Was PEM encoded
|
|
*/
|
|
dhminlen = pem.buflen;
|
|
}
|
|
else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
|
|
goto exit;
|
|
|
|
p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin;
|
|
#else
|
|
p = (unsigned char *) dhmin;
|
|
#endif /* MBEDTLS_PEM_PARSE_C */
|
|
end = p + dhminlen;
|
|
|
|
/*
|
|
* DHParams ::= SEQUENCE {
|
|
* prime INTEGER, -- P
|
|
* generator INTEGER, -- g
|
|
* privateValueLength INTEGER OPTIONAL
|
|
* }
|
|
*/
|
|
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
|
|
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
|
|
goto exit;
|
|
}
|
|
|
|
end = p + len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 ||
|
|
( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
|
|
goto exit;
|
|
}
|
|
|
|
if( p != end )
|
|
{
|
|
/* This might be the optional privateValueLength.
|
|
* If so, we can cleanly discard it */
|
|
mbedtls_mpi rec;
|
|
mbedtls_mpi_init( &rec );
|
|
ret = mbedtls_asn1_get_mpi( &p, end, &rec );
|
|
mbedtls_mpi_free( &rec );
|
|
if ( ret != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
|
|
goto exit;
|
|
}
|
|
if ( p != end )
|
|
{
|
|
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT +
|
|
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
dhm->len = mbedtls_mpi_size( &dhm->P );
|
|
|
|
exit:
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
mbedtls_pem_free( &pem );
|
|
#endif
|
|
if( ret != 0 )
|
|
mbedtls_dhm_free( dhm );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_FS_IO)
|
|
/*
|
|
* Load all data from a file into a given buffer.
|
|
*
|
|
* The file is expected to contain either PEM or DER encoded data.
|
|
* A terminating null byte is always appended. It is included in the announced
|
|
* length only if the data looks like it is PEM encoded.
|
|
*/
|
|
static int load_file( const char *path, unsigned char **buf, size_t *n )
|
|
{
|
|
FILE *f;
|
|
long size;
|
|
|
|
if( ( f = fopen( path, "rb" ) ) == NULL )
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
|
|
fseek( f, 0, SEEK_END );
|
|
if( ( size = ftell( f ) ) == -1 )
|
|
{
|
|
fclose( f );
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
}
|
|
fseek( f, 0, SEEK_SET );
|
|
|
|
*n = (size_t) size;
|
|
|
|
if( *n + 1 == 0 ||
|
|
( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
|
|
{
|
|
fclose( f );
|
|
return( MBEDTLS_ERR_DHM_ALLOC_FAILED );
|
|
}
|
|
|
|
if( fread( *buf, 1, *n, f ) != *n )
|
|
{
|
|
fclose( f );
|
|
mbedtls_free( *buf );
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
}
|
|
|
|
fclose( f );
|
|
|
|
(*buf)[*n] = '\0';
|
|
|
|
if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
|
|
++*n;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Load and parse DHM parameters
|
|
*/
|
|
int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path )
|
|
{
|
|
int ret;
|
|
size_t n;
|
|
unsigned char *buf;
|
|
|
|
if( ( ret = load_file( path, &buf, &n ) ) != 0 )
|
|
return( ret );
|
|
|
|
ret = mbedtls_dhm_parse_dhm( dhm, buf, n );
|
|
|
|
mbedtls_zeroize( buf, n );
|
|
mbedtls_free( buf );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_FS_IO */
|
|
#endif /* MBEDTLS_ASN1_PARSE_C */
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
|
|
static const char mbedtls_test_dhm_params[] =
|
|
"-----BEGIN DH PARAMETERS-----\r\n"
|
|
"MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
|
|
"1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
|
|
"9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
|
|
"-----END DH PARAMETERS-----\r\n";
|
|
|
|
static const size_t mbedtls_test_dhm_params_len = sizeof( mbedtls_test_dhm_params );
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int mbedtls_dhm_self_test( int verbose )
|
|
{
|
|
int ret;
|
|
mbedtls_dhm_context dhm;
|
|
|
|
mbedtls_dhm_init( &dhm );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " DHM parameter load: " );
|
|
|
|
if( ( ret = mbedtls_dhm_parse_dhm( &dhm,
|
|
(const unsigned char *) mbedtls_test_dhm_params,
|
|
mbedtls_test_dhm_params_len ) ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto exit;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n\n" );
|
|
|
|
exit:
|
|
mbedtls_dhm_free( &dhm );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_DHM_C */
|