Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Diffie-Hellman-Merkle key exchange |
| 3 | * |
Manuel Pégourié-Gonnard | 6fb8187 | 2015-07-27 11:11:48 +0200 | [diff] [blame^] | 4 | * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
Paul Bakker | b96f154 | 2010-07-18 20:36:00 +0000 | [diff] [blame] | 5 | * |
Manuel Pégourié-Gonnard | fe44643 | 2015-03-06 13:17:10 +0000 | [diff] [blame] | 6 | * This file is part of mbed TLS (https://tls.mbed.org) |
Paul Bakker | b96f154 | 2010-07-18 20:36:00 +0000 | [diff] [blame] | 7 | * |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along |
| 19 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | */ |
| 22 | /* |
| 23 | * Reference: |
| 24 | * |
| 25 | * http://www.cacr.math.uwaterloo.ca/hac/ (chapter 12) |
| 26 | */ |
| 27 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 28 | #if !defined(MBEDTLS_CONFIG_FILE) |
Manuel Pégourié-Gonnard | 7f80997 | 2015-03-09 17:05:11 +0000 | [diff] [blame] | 29 | #include "mbedtls/config.h" |
Manuel Pégourié-Gonnard | cef4ad2 | 2014-04-29 12:39:06 +0200 | [diff] [blame] | 30 | #else |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 31 | #include MBEDTLS_CONFIG_FILE |
Manuel Pégourié-Gonnard | cef4ad2 | 2014-04-29 12:39:06 +0200 | [diff] [blame] | 32 | #endif |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 33 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 34 | #if defined(MBEDTLS_DHM_C) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 35 | |
Manuel Pégourié-Gonnard | 7f80997 | 2015-03-09 17:05:11 +0000 | [diff] [blame] | 36 | #include "mbedtls/dhm.h" |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 37 | |
Rich Evans | 00ab470 | 2015-02-06 13:43:58 +0000 | [diff] [blame] | 38 | #include <string.h> |
| 39 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 40 | #if defined(MBEDTLS_PEM_PARSE_C) |
Manuel Pégourié-Gonnard | 7f80997 | 2015-03-09 17:05:11 +0000 | [diff] [blame] | 41 | #include "mbedtls/pem.h" |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 42 | #endif |
| 43 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 44 | #if defined(MBEDTLS_ASN1_PARSE_C) |
Manuel Pégourié-Gonnard | 7f80997 | 2015-03-09 17:05:11 +0000 | [diff] [blame] | 45 | #include "mbedtls/asn1.h" |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 46 | #endif |
| 47 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 48 | #if defined(MBEDTLS_PLATFORM_C) |
Manuel Pégourié-Gonnard | 7f80997 | 2015-03-09 17:05:11 +0000 | [diff] [blame] | 49 | #include "mbedtls/platform.h" |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 50 | #else |
| 51 | #include <stdlib.h> |
Manuel Pégourié-Gonnard | 981732b | 2015-02-17 15:46:45 +0000 | [diff] [blame] | 52 | #include <stdio.h> |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 53 | #define mbedtls_printf printf |
Manuel Pégourié-Gonnard | 7551cb9 | 2015-05-26 16:04:06 +0200 | [diff] [blame] | 54 | #define mbedtls_calloc calloc |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 55 | #define mbedtls_free free |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 56 | #endif |
| 57 | |
Paul Bakker | 3461772 | 2014-06-13 17:20:13 +0200 | [diff] [blame] | 58 | /* Implementation that should never be optimized out by the compiler */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 59 | static void mbedtls_zeroize( void *v, size_t n ) { |
Paul Bakker | 3461772 | 2014-06-13 17:20:13 +0200 | [diff] [blame] | 60 | volatile unsigned char *p = v; while( n-- ) *p++ = 0; |
| 61 | } |
| 62 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 63 | /* |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 64 | * helper to validate the mbedtls_mpi size and import it |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 65 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 66 | static int dhm_read_bignum( mbedtls_mpi *X, |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 67 | unsigned char **p, |
Paul Bakker | ff60ee6 | 2010-03-16 21:09:09 +0000 | [diff] [blame] | 68 | const unsigned char *end ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 69 | { |
| 70 | int ret, n; |
| 71 | |
| 72 | if( end - *p < 2 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 73 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 74 | |
| 75 | n = ( (*p)[0] << 8 ) | (*p)[1]; |
| 76 | (*p) += 2; |
| 77 | |
| 78 | if( (int)( end - *p ) < n ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 79 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 80 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 81 | if( ( ret = mbedtls_mpi_read_binary( X, *p, n ) ) != 0 ) |
| 82 | return( MBEDTLS_ERR_DHM_READ_PARAMS_FAILED + ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 83 | |
| 84 | (*p) += n; |
| 85 | |
| 86 | return( 0 ); |
| 87 | } |
| 88 | |
| 89 | /* |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 90 | * Verify sanity of parameter with regards to P |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 91 | * |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 92 | * Parameter should be: 2 <= public_param <= P - 2 |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 93 | * |
| 94 | * For more information on the attack, see: |
| 95 | * http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf |
| 96 | * http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643 |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 97 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 98 | static int dhm_check_range( const mbedtls_mpi *param, const mbedtls_mpi *P ) |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 99 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 100 | mbedtls_mpi L, U; |
| 101 | int ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA; |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 102 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 103 | mbedtls_mpi_init( &L ); mbedtls_mpi_init( &U ); |
Paul Bakker | 3d8fb63 | 2014-04-17 12:42:41 +0200 | [diff] [blame] | 104 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 105 | MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &L, 2 ) ); |
| 106 | MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &U, P, 2 ) ); |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 107 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 108 | if( mbedtls_mpi_cmp_mpi( param, &L ) >= 0 && |
| 109 | mbedtls_mpi_cmp_mpi( param, &U ) <= 0 ) |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 110 | { |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 111 | ret = 0; |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 112 | } |
| 113 | |
Paul Bakker | 3d8fb63 | 2014-04-17 12:42:41 +0200 | [diff] [blame] | 114 | cleanup: |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 115 | mbedtls_mpi_free( &L ); mbedtls_mpi_free( &U ); |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 116 | return( ret ); |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 117 | } |
| 118 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 119 | void mbedtls_dhm_init( mbedtls_dhm_context *ctx ) |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 120 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 121 | memset( ctx, 0, sizeof( mbedtls_dhm_context ) ); |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 122 | } |
| 123 | |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 124 | /* |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 125 | * Parse the ServerKeyExchange parameters |
| 126 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 127 | int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx, |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 128 | unsigned char **p, |
Paul Bakker | ff60ee6 | 2010-03-16 21:09:09 +0000 | [diff] [blame] | 129 | const unsigned char *end ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 130 | { |
Paul Bakker | 13ed9ab | 2012-04-16 09:43:49 +0000 | [diff] [blame] | 131 | int ret; |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 132 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 133 | if( ( ret = dhm_read_bignum( &ctx->P, p, end ) ) != 0 || |
| 134 | ( ret = dhm_read_bignum( &ctx->G, p, end ) ) != 0 || |
| 135 | ( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 ) |
| 136 | return( ret ); |
| 137 | |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 138 | if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 ) |
| 139 | return( ret ); |
| 140 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 141 | ctx->len = mbedtls_mpi_size( &ctx->P ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 142 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 143 | return( 0 ); |
| 144 | } |
| 145 | |
| 146 | /* |
| 147 | * Setup and write the ServerKeyExchange parameters |
| 148 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 149 | int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size, |
Paul Bakker | 23986e5 | 2011-04-24 08:57:21 +0000 | [diff] [blame] | 150 | unsigned char *output, size_t *olen, |
Paul Bakker | a3d195c | 2011-11-27 21:07:34 +0000 | [diff] [blame] | 151 | int (*f_rng)(void *, unsigned char *, size_t), |
| 152 | void *p_rng ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 153 | { |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 154 | int ret, count = 0; |
Paul Bakker | 23986e5 | 2011-04-24 08:57:21 +0000 | [diff] [blame] | 155 | size_t n1, n2, n3; |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 156 | unsigned char *p; |
| 157 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 158 | if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 ) |
| 159 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | b5b20f1 | 2012-09-16 15:07:49 +0000 | [diff] [blame] | 160 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 161 | /* |
Paul Bakker | ff7fe67 | 2010-07-18 09:45:05 +0000 | [diff] [blame] | 162 | * Generate X as large as possible ( < P ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 163 | */ |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 164 | do |
| 165 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 166 | mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 167 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 168 | while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 ) |
| 169 | MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) ); |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 170 | |
| 171 | if( count++ > 10 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 172 | return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED ); |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 173 | } |
| 174 | while( dhm_check_range( &ctx->X, &ctx->P ) != 0 ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 175 | |
Paul Bakker | ff7fe67 | 2010-07-18 09:45:05 +0000 | [diff] [blame] | 176 | /* |
| 177 | * Calculate GX = G^X mod P |
| 178 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 179 | MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X, |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 180 | &ctx->P , &ctx->RP ) ); |
| 181 | |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 182 | if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 ) |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 183 | return( ret ); |
| 184 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 185 | /* |
| 186 | * export P, G, GX |
| 187 | */ |
| 188 | #define DHM_MPI_EXPORT(X,n) \ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 189 | MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, p + 2, n ) ); \ |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 190 | *p++ = (unsigned char)( n >> 8 ); \ |
| 191 | *p++ = (unsigned char)( n ); p += n; |
| 192 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 193 | n1 = mbedtls_mpi_size( &ctx->P ); |
| 194 | n2 = mbedtls_mpi_size( &ctx->G ); |
| 195 | n3 = mbedtls_mpi_size( &ctx->GX ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 196 | |
| 197 | p = output; |
| 198 | DHM_MPI_EXPORT( &ctx->P , n1 ); |
| 199 | DHM_MPI_EXPORT( &ctx->G , n2 ); |
| 200 | DHM_MPI_EXPORT( &ctx->GX, n3 ); |
| 201 | |
| 202 | *olen = p - output; |
| 203 | |
| 204 | ctx->len = n1; |
| 205 | |
| 206 | cleanup: |
| 207 | |
| 208 | if( ret != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 209 | return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED + ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 210 | |
| 211 | return( 0 ); |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Import the peer's public value G^Y |
| 216 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 217 | int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx, |
Paul Bakker | 23986e5 | 2011-04-24 08:57:21 +0000 | [diff] [blame] | 218 | const unsigned char *input, size_t ilen ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 219 | { |
| 220 | int ret; |
| 221 | |
| 222 | if( ctx == NULL || ilen < 1 || ilen > ctx->len ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 223 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 224 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 225 | if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 ) |
| 226 | return( MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED + ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 227 | |
| 228 | return( 0 ); |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * Create own private value X and export G^X |
| 233 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 234 | int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size, |
Paul Bakker | 23986e5 | 2011-04-24 08:57:21 +0000 | [diff] [blame] | 235 | unsigned char *output, size_t olen, |
Paul Bakker | a3d195c | 2011-11-27 21:07:34 +0000 | [diff] [blame] | 236 | int (*f_rng)(void *, unsigned char *, size_t), |
| 237 | void *p_rng ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 238 | { |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 239 | int ret, count = 0; |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 240 | |
| 241 | if( ctx == NULL || olen < 1 || olen > ctx->len ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 242 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 243 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 244 | if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 ) |
| 245 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | b5b20f1 | 2012-09-16 15:07:49 +0000 | [diff] [blame] | 246 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 247 | /* |
| 248 | * generate X and calculate GX = G^X mod P |
| 249 | */ |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 250 | do |
| 251 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 252 | mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 253 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 254 | while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 ) |
| 255 | MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) ); |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 256 | |
| 257 | if( count++ > 10 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 258 | return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED ); |
Paul Bakker | aec37cb | 2012-04-26 18:59:59 +0000 | [diff] [blame] | 259 | } |
| 260 | while( dhm_check_range( &ctx->X, &ctx->P ) != 0 ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 261 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 262 | MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X, |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 263 | &ctx->P , &ctx->RP ) ); |
| 264 | |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 265 | if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 ) |
| 266 | return( ret ); |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 267 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 268 | MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->GX, output, olen ) ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 269 | |
| 270 | cleanup: |
| 271 | |
| 272 | if( ret != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 273 | return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED + ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 274 | |
| 275 | return( 0 ); |
| 276 | } |
| 277 | |
| 278 | /* |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 279 | * Use the blinding method and optimisation suggested in section 10 of: |
| 280 | * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA, |
Manuel Pégourié-Gonnard | 998930a | 2015-04-03 13:48:06 +0200 | [diff] [blame] | 281 | * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 282 | * Berlin Heidelberg, 1996. p. 104-113. |
| 283 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 284 | static int dhm_update_blinding( mbedtls_dhm_context *ctx, |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 285 | int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) |
| 286 | { |
| 287 | int ret, count; |
| 288 | |
| 289 | /* |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 290 | * Don't use any blinding the first time a particular X is used, |
| 291 | * but remember it to use blinding next time. |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 292 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 293 | if( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->pX ) != 0 ) |
Manuel Pégourié-Gonnard | ed8a02b | 2013-09-04 16:39:03 +0200 | [diff] [blame] | 294 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 295 | MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &ctx->pX, &ctx->X ) ); |
| 296 | MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vi, 1 ) ); |
| 297 | MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vf, 1 ) ); |
Manuel Pégourié-Gonnard | ed8a02b | 2013-09-04 16:39:03 +0200 | [diff] [blame] | 298 | |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 299 | return( 0 ); |
| 300 | } |
| 301 | |
| 302 | /* |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 303 | * Ok, we need blinding. Can we re-use existing values? |
| 304 | * If yes, just update them by squaring them. |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 305 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 306 | if( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 ) |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 307 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 308 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) ); |
| 309 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) ); |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 310 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 311 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) ); |
| 312 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) ); |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 313 | |
| 314 | return( 0 ); |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * We need to generate blinding values from scratch |
| 319 | */ |
| 320 | |
| 321 | /* Vi = random( 2, P-1 ) */ |
| 322 | count = 0; |
| 323 | do |
| 324 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 325 | mbedtls_mpi_fill_random( &ctx->Vi, mbedtls_mpi_size( &ctx->P ), f_rng, p_rng ); |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 326 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 327 | while( mbedtls_mpi_cmp_mpi( &ctx->Vi, &ctx->P ) >= 0 ) |
| 328 | MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->Vi, 1 ) ); |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 329 | |
| 330 | if( count++ > 10 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 331 | return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE ); |
Manuel Pégourié-Gonnard | 15d5de1 | 2013-09-17 11:34:11 +0200 | [diff] [blame] | 332 | } |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 333 | while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) <= 0 ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 334 | |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 335 | /* Vf = Vi^-X mod P */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 336 | MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vf, &ctx->Vi, &ctx->P ) ); |
| 337 | MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP ) ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 338 | |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 339 | cleanup: |
| 340 | return( ret ); |
| 341 | } |
| 342 | |
| 343 | /* |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 344 | * Derive and export the shared secret (G^Y)^X mod P |
| 345 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 346 | int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx, |
Manuel Pégourié-Gonnard | 3335205 | 2015-06-02 16:17:08 +0100 | [diff] [blame] | 347 | unsigned char *output, size_t output_size, size_t *olen, |
Manuel Pégourié-Gonnard | 2d62764 | 2013-09-04 14:22:07 +0200 | [diff] [blame] | 348 | int (*f_rng)(void *, unsigned char *, size_t), |
| 349 | void *p_rng ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 350 | { |
| 351 | int ret; |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 352 | mbedtls_mpi GYb; |
Manuel Pégourié-Gonnard | 2d62764 | 2013-09-04 14:22:07 +0200 | [diff] [blame] | 353 | |
Manuel Pégourié-Gonnard | 3335205 | 2015-06-02 16:17:08 +0100 | [diff] [blame] | 354 | if( ctx == NULL || output_size < ctx->len ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 355 | return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 356 | |
Paul Bakker | 345a6fe | 2011-02-28 21:20:02 +0000 | [diff] [blame] | 357 | if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 ) |
Paul Bakker | c47840e | 2011-02-20 16:37:30 +0000 | [diff] [blame] | 358 | return( ret ); |
| 359 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 360 | mbedtls_mpi_init( &GYb ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 361 | |
| 362 | /* Blind peer's value */ |
Manuel Pégourié-Gonnard | ed8a02b | 2013-09-04 16:39:03 +0200 | [diff] [blame] | 363 | if( f_rng != NULL ) |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 364 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 365 | MBEDTLS_MPI_CHK( dhm_update_blinding( ctx, f_rng, p_rng ) ); |
| 366 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &GYb, &ctx->GY, &ctx->Vi ) ); |
| 367 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &GYb, &GYb, &ctx->P ) ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 368 | } |
| 369 | else |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 370 | MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &GYb, &ctx->GY ) ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 371 | |
| 372 | /* Do modular exponentiation */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 373 | MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->K, &GYb, &ctx->X, |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 374 | &ctx->P, &ctx->RP ) ); |
| 375 | |
| 376 | /* Unblind secret value */ |
Manuel Pégourié-Gonnard | ed8a02b | 2013-09-04 16:39:03 +0200 | [diff] [blame] | 377 | if( f_rng != NULL ) |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 378 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 379 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->K, &ctx->K, &ctx->Vf ) ); |
| 380 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->K, &ctx->K, &ctx->P ) ); |
Manuel Pégourié-Gonnard | 143b502 | 2013-09-04 16:29:59 +0200 | [diff] [blame] | 381 | } |
| 382 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 383 | *olen = mbedtls_mpi_size( &ctx->K ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 384 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 385 | MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->K, output, *olen ) ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 386 | |
| 387 | cleanup: |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 388 | mbedtls_mpi_free( &GYb ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 389 | |
| 390 | if( ret != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 391 | return( MBEDTLS_ERR_DHM_CALC_SECRET_FAILED + ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 392 | |
| 393 | return( 0 ); |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * Free the components of a DHM key |
| 398 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 399 | void mbedtls_dhm_free( mbedtls_dhm_context *ctx ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 400 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 401 | mbedtls_mpi_free( &ctx->pX); mbedtls_mpi_free( &ctx->Vf ); mbedtls_mpi_free( &ctx->Vi ); |
| 402 | mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->K ); mbedtls_mpi_free( &ctx->GY ); |
| 403 | mbedtls_mpi_free( &ctx->GX ); mbedtls_mpi_free( &ctx->X ); mbedtls_mpi_free( &ctx->G ); |
| 404 | mbedtls_mpi_free( &ctx->P ); |
Manuel Pégourié-Gonnard | b72b4ed | 2013-09-13 13:55:26 +0200 | [diff] [blame] | 405 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 406 | mbedtls_zeroize( ctx, sizeof( mbedtls_dhm_context ) ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 407 | } |
| 408 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 409 | #if defined(MBEDTLS_ASN1_PARSE_C) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 410 | /* |
| 411 | * Parse DHM parameters |
| 412 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 413 | int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin, |
Paul Bakker | b9e4e2c | 2014-05-01 14:18:25 +0200 | [diff] [blame] | 414 | size_t dhminlen ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 415 | { |
| 416 | int ret; |
| 417 | size_t len; |
| 418 | unsigned char *p, *end; |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 419 | #if defined(MBEDTLS_PEM_PARSE_C) |
| 420 | mbedtls_pem_context pem; |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 421 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 422 | mbedtls_pem_init( &pem ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 423 | |
Manuel Pégourié-Gonnard | 43b37cb | 2015-05-12 11:20:10 +0200 | [diff] [blame] | 424 | /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */ |
Manuel Pégourié-Gonnard | 0ece0f9 | 2015-05-12 12:43:54 +0200 | [diff] [blame] | 425 | if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' ) |
Manuel Pégourié-Gonnard | 43b37cb | 2015-05-12 11:20:10 +0200 | [diff] [blame] | 426 | ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT; |
| 427 | else |
| 428 | ret = mbedtls_pem_read_buffer( &pem, |
| 429 | "-----BEGIN DH PARAMETERS-----", |
| 430 | "-----END DH PARAMETERS-----", |
| 431 | dhmin, NULL, 0, &dhminlen ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 432 | |
| 433 | if( ret == 0 ) |
| 434 | { |
| 435 | /* |
| 436 | * Was PEM encoded |
| 437 | */ |
| 438 | dhminlen = pem.buflen; |
| 439 | } |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 440 | else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 441 | goto exit; |
| 442 | |
| 443 | p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin; |
| 444 | #else |
| 445 | p = (unsigned char *) dhmin; |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 446 | #endif /* MBEDTLS_PEM_PARSE_C */ |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 447 | end = p + dhminlen; |
| 448 | |
| 449 | /* |
| 450 | * DHParams ::= SEQUENCE { |
Daniel Kahn Gillmor | 2ed8173 | 2015-04-03 13:09:24 -0400 | [diff] [blame] | 451 | * prime INTEGER, -- P |
| 452 | * generator INTEGER, -- g |
| 453 | * privateValueLength INTEGER OPTIONAL |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 454 | * } |
| 455 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 456 | if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, |
| 457 | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 458 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 459 | ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret; |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 460 | goto exit; |
| 461 | } |
| 462 | |
| 463 | end = p + len; |
| 464 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 465 | if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 || |
| 466 | ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 467 | { |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 468 | ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret; |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 469 | goto exit; |
| 470 | } |
| 471 | |
| 472 | if( p != end ) |
| 473 | { |
Manuel Pégourié-Gonnard | de9b363 | 2015-04-17 20:06:31 +0200 | [diff] [blame] | 474 | /* This might be the optional privateValueLength. |
| 475 | * If so, we can cleanly discard it */ |
| 476 | mbedtls_mpi rec; |
| 477 | mbedtls_mpi_init( &rec ); |
| 478 | ret = mbedtls_asn1_get_mpi( &p, end, &rec ); |
| 479 | mbedtls_mpi_free( &rec ); |
Daniel Kahn Gillmor | 2ed8173 | 2015-04-03 13:09:24 -0400 | [diff] [blame] | 480 | if ( ret != 0 ) |
| 481 | { |
Manuel Pégourié-Gonnard | de9b363 | 2015-04-17 20:06:31 +0200 | [diff] [blame] | 482 | ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret; |
Daniel Kahn Gillmor | 2ed8173 | 2015-04-03 13:09:24 -0400 | [diff] [blame] | 483 | goto exit; |
| 484 | } |
| 485 | if ( p != end ) |
| 486 | { |
Manuel Pégourié-Gonnard | de9b363 | 2015-04-17 20:06:31 +0200 | [diff] [blame] | 487 | ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + |
| 488 | MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; |
Daniel Kahn Gillmor | 2ed8173 | 2015-04-03 13:09:24 -0400 | [diff] [blame] | 489 | goto exit; |
| 490 | } |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 491 | } |
| 492 | |
| 493 | ret = 0; |
| 494 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 495 | dhm->len = mbedtls_mpi_size( &dhm->P ); |
Manuel Pégourié-Gonnard | 3fec220 | 2014-03-29 16:42:38 +0100 | [diff] [blame] | 496 | |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 497 | exit: |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 498 | #if defined(MBEDTLS_PEM_PARSE_C) |
| 499 | mbedtls_pem_free( &pem ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 500 | #endif |
| 501 | if( ret != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 502 | mbedtls_dhm_free( dhm ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 503 | |
| 504 | return( ret ); |
| 505 | } |
| 506 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 507 | #if defined(MBEDTLS_FS_IO) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 508 | /* |
| 509 | * Load all data from a file into a given buffer. |
Manuel Pégourié-Gonnard | 43b37cb | 2015-05-12 11:20:10 +0200 | [diff] [blame] | 510 | * |
| 511 | * The file is expected to contain either PEM or DER encoded data. |
| 512 | * A terminating null byte is always appended. It is included in the announced |
| 513 | * length only if the data looks like it is PEM encoded. |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 514 | */ |
| 515 | static int load_file( const char *path, unsigned char **buf, size_t *n ) |
| 516 | { |
| 517 | FILE *f; |
| 518 | long size; |
| 519 | |
| 520 | if( ( f = fopen( path, "rb" ) ) == NULL ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 521 | return( MBEDTLS_ERR_DHM_FILE_IO_ERROR ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 522 | |
| 523 | fseek( f, 0, SEEK_END ); |
| 524 | if( ( size = ftell( f ) ) == -1 ) |
| 525 | { |
| 526 | fclose( f ); |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 527 | return( MBEDTLS_ERR_DHM_FILE_IO_ERROR ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 528 | } |
| 529 | fseek( f, 0, SEEK_SET ); |
| 530 | |
| 531 | *n = (size_t) size; |
| 532 | |
| 533 | if( *n + 1 == 0 || |
Manuel Pégourié-Gonnard | 7551cb9 | 2015-05-26 16:04:06 +0200 | [diff] [blame] | 534 | ( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 535 | { |
| 536 | fclose( f ); |
Manuel Pégourié-Gonnard | 6a8ca33 | 2015-05-28 09:33:39 +0200 | [diff] [blame] | 537 | return( MBEDTLS_ERR_DHM_ALLOC_FAILED ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 538 | } |
| 539 | |
| 540 | if( fread( *buf, 1, *n, f ) != *n ) |
| 541 | { |
| 542 | fclose( f ); |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 543 | mbedtls_free( *buf ); |
| 544 | return( MBEDTLS_ERR_DHM_FILE_IO_ERROR ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 545 | } |
| 546 | |
| 547 | fclose( f ); |
| 548 | |
| 549 | (*buf)[*n] = '\0'; |
| 550 | |
Manuel Pégourié-Gonnard | 43b37cb | 2015-05-12 11:20:10 +0200 | [diff] [blame] | 551 | if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL ) |
| 552 | ++*n; |
| 553 | |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 554 | return( 0 ); |
| 555 | } |
| 556 | |
| 557 | /* |
| 558 | * Load and parse DHM parameters |
| 559 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 560 | int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 561 | { |
| 562 | int ret; |
| 563 | size_t n; |
| 564 | unsigned char *buf; |
| 565 | |
Paul Bakker | 66d5d07 | 2014-06-17 16:39:18 +0200 | [diff] [blame] | 566 | if( ( ret = load_file( path, &buf, &n ) ) != 0 ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 567 | return( ret ); |
| 568 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 569 | ret = mbedtls_dhm_parse_dhm( dhm, buf, n ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 570 | |
Manuel Pégourié-Gonnard | 43b37cb | 2015-05-12 11:20:10 +0200 | [diff] [blame] | 571 | mbedtls_zeroize( buf, n ); |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 572 | mbedtls_free( buf ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 573 | |
| 574 | return( ret ); |
| 575 | } |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 576 | #endif /* MBEDTLS_FS_IO */ |
| 577 | #endif /* MBEDTLS_ASN1_PARSE_C */ |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 578 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 579 | #if defined(MBEDTLS_SELF_TEST) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 580 | |
Manuel Pégourié-Gonnard | 53585ee | 2015-06-25 08:52:25 +0200 | [diff] [blame] | 581 | static const char mbedtls_test_dhm_params[] = |
| 582 | "-----BEGIN DH PARAMETERS-----\r\n" |
| 583 | "MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n" |
| 584 | "1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n" |
| 585 | "9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n" |
| 586 | "-----END DH PARAMETERS-----\r\n"; |
| 587 | |
| 588 | static const size_t mbedtls_test_dhm_params_len = sizeof( mbedtls_test_dhm_params ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 589 | |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 590 | /* |
| 591 | * Checkup routine |
| 592 | */ |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 593 | int mbedtls_dhm_self_test( int verbose ) |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 594 | { |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 595 | int ret; |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 596 | mbedtls_dhm_context dhm; |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 597 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 598 | mbedtls_dhm_init( &dhm ); |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 599 | |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 600 | if( verbose != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 601 | mbedtls_printf( " DHM parameter load: " ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 602 | |
Manuel Pégourié-Gonnard | 53585ee | 2015-06-25 08:52:25 +0200 | [diff] [blame] | 603 | if( ( ret = mbedtls_dhm_parse_dhm( &dhm, |
| 604 | (const unsigned char *) mbedtls_test_dhm_params, |
| 605 | mbedtls_test_dhm_params_len ) ) != 0 ) |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 606 | { |
| 607 | if( verbose != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 608 | mbedtls_printf( "failed\n" ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 609 | |
Manuel Pégourié-Gonnard | b196fc2 | 2014-07-09 16:53:29 +0200 | [diff] [blame] | 610 | ret = 1; |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 611 | goto exit; |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 612 | } |
| 613 | |
| 614 | if( verbose != 0 ) |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 615 | mbedtls_printf( "passed\n\n" ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 616 | |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 617 | exit: |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 618 | mbedtls_dhm_free( &dhm ); |
Paul Bakker | 40ce79f | 2013-09-15 17:43:54 +0200 | [diff] [blame] | 619 | |
Paul Bakker | 8f870b0 | 2014-06-20 13:32:38 +0200 | [diff] [blame] | 620 | return( ret ); |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 621 | } |
| 622 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 623 | #endif /* MBEDTLS_SELF_TEST */ |
Paul Bakker | 5121ce5 | 2009-01-03 21:22:43 +0000 | [diff] [blame] | 624 | |
Manuel Pégourié-Gonnard | 2cf5a7c | 2015-04-08 12:49:31 +0200 | [diff] [blame] | 625 | #endif /* MBEDTLS_DHM_C */ |