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mbed-os/features/mbedtls/src/ssl_cookie.c@1:9c5af431a1f1, 2018-05-01 (annotated)

Committer:
gustavatmel
Date:
Tue May 01 15:47:08 2018 +0000
Revision:
1:9c5af431a1f1
sdf

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gustavatmel 1:9c5af431a1f1 1 /*
gustavatmel 1:9c5af431a1f1 2 * DTLS cookie callbacks implementation
gustavatmel 1:9c5af431a1f1 3 *
gustavatmel 1:9c5af431a1f1 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
gustavatmel 1:9c5af431a1f1 5 * SPDX-License-Identifier: Apache-2.0
gustavatmel 1:9c5af431a1f1 6 *
gustavatmel 1:9c5af431a1f1 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
gustavatmel 1:9c5af431a1f1 8 * not use this file except in compliance with the License.
gustavatmel 1:9c5af431a1f1 9 * You may obtain a copy of the License at
gustavatmel 1:9c5af431a1f1 10 *
gustavatmel 1:9c5af431a1f1 11 * http://www.apache.org/licenses/LICENSE-2.0
gustavatmel 1:9c5af431a1f1 12 *
gustavatmel 1:9c5af431a1f1 13 * Unless required by applicable law or agreed to in writing, software
gustavatmel 1:9c5af431a1f1 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
gustavatmel 1:9c5af431a1f1 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
gustavatmel 1:9c5af431a1f1 16 * See the License for the specific language governing permissions and
gustavatmel 1:9c5af431a1f1 17 * limitations under the License.
gustavatmel 1:9c5af431a1f1 18 *
gustavatmel 1:9c5af431a1f1 19 * This file is part of mbed TLS (https://tls.mbed.org)
gustavatmel 1:9c5af431a1f1 20 */
gustavatmel 1:9c5af431a1f1 21 /*
gustavatmel 1:9c5af431a1f1 22 * These session callbacks use a simple chained list
gustavatmel 1:9c5af431a1f1 23 * to store and retrieve the session information.
gustavatmel 1:9c5af431a1f1 24 */
gustavatmel 1:9c5af431a1f1 25
gustavatmel 1:9c5af431a1f1 26 #if !defined(MBEDTLS_CONFIG_FILE)
gustavatmel 1:9c5af431a1f1 27 #include "mbedtls/config.h"
gustavatmel 1:9c5af431a1f1 28 #else
gustavatmel 1:9c5af431a1f1 29 #include MBEDTLS_CONFIG_FILE
gustavatmel 1:9c5af431a1f1 30 #endif
gustavatmel 1:9c5af431a1f1 31
gustavatmel 1:9c5af431a1f1 32 #if defined(MBEDTLS_SSL_COOKIE_C)
gustavatmel 1:9c5af431a1f1 33
gustavatmel 1:9c5af431a1f1 34 #if defined(MBEDTLS_PLATFORM_C)
gustavatmel 1:9c5af431a1f1 35 #include "mbedtls/platform.h"
gustavatmel 1:9c5af431a1f1 36 #else
gustavatmel 1:9c5af431a1f1 37 #define mbedtls_calloc calloc
gustavatmel 1:9c5af431a1f1 38 #define mbedtls_free free
gustavatmel 1:9c5af431a1f1 39 #endif
gustavatmel 1:9c5af431a1f1 40
gustavatmel 1:9c5af431a1f1 41 #include "mbedtls/ssl_cookie.h"
gustavatmel 1:9c5af431a1f1 42 #include "mbedtls/ssl_internal.h"
gustavatmel 1:9c5af431a1f1 43
gustavatmel 1:9c5af431a1f1 44 #include <string.h>
gustavatmel 1:9c5af431a1f1 45
gustavatmel 1:9c5af431a1f1 46 /* Implementation that should never be optimized out by the compiler */
gustavatmel 1:9c5af431a1f1 47 static void mbedtls_zeroize( void *v, size_t n ) {
gustavatmel 1:9c5af431a1f1 48 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
gustavatmel 1:9c5af431a1f1 49 }
gustavatmel 1:9c5af431a1f1 50
gustavatmel 1:9c5af431a1f1 51 /*
gustavatmel 1:9c5af431a1f1 52 * If DTLS is in use, then at least one of SHA-1, SHA-256, SHA-512 is
gustavatmel 1:9c5af431a1f1 53 * available. Try SHA-256 first, 512 wastes resources since we need to stay
gustavatmel 1:9c5af431a1f1 54 * with max 32 bytes of cookie for DTLS 1.0
gustavatmel 1:9c5af431a1f1 55 */
gustavatmel 1:9c5af431a1f1 56 #if defined(MBEDTLS_SHA256_C)
gustavatmel 1:9c5af431a1f1 57 #define COOKIE_MD MBEDTLS_MD_SHA224
gustavatmel 1:9c5af431a1f1 58 #define COOKIE_MD_OUTLEN 32
gustavatmel 1:9c5af431a1f1 59 #define COOKIE_HMAC_LEN 28
gustavatmel 1:9c5af431a1f1 60 #elif defined(MBEDTLS_SHA512_C)
gustavatmel 1:9c5af431a1f1 61 #define COOKIE_MD MBEDTLS_MD_SHA384
gustavatmel 1:9c5af431a1f1 62 #define COOKIE_MD_OUTLEN 48
gustavatmel 1:9c5af431a1f1 63 #define COOKIE_HMAC_LEN 28
gustavatmel 1:9c5af431a1f1 64 #elif defined(MBEDTLS_SHA1_C)
gustavatmel 1:9c5af431a1f1 65 #define COOKIE_MD MBEDTLS_MD_SHA1
gustavatmel 1:9c5af431a1f1 66 #define COOKIE_MD_OUTLEN 20
gustavatmel 1:9c5af431a1f1 67 #define COOKIE_HMAC_LEN 20
gustavatmel 1:9c5af431a1f1 68 #else
gustavatmel 1:9c5af431a1f1 69 #error "DTLS hello verify needs SHA-1 or SHA-2"
gustavatmel 1:9c5af431a1f1 70 #endif
gustavatmel 1:9c5af431a1f1 71
gustavatmel 1:9c5af431a1f1 72 /*
gustavatmel 1:9c5af431a1f1 73 * Cookies are formed of a 4-bytes timestamp (or serial number) and
gustavatmel 1:9c5af431a1f1 74 * an HMAC of timestemp and client ID.
gustavatmel 1:9c5af431a1f1 75 */
gustavatmel 1:9c5af431a1f1 76 #define COOKIE_LEN ( 4 + COOKIE_HMAC_LEN )
gustavatmel 1:9c5af431a1f1 77
gustavatmel 1:9c5af431a1f1 78 void mbedtls_ssl_cookie_init( mbedtls_ssl_cookie_ctx *ctx )
gustavatmel 1:9c5af431a1f1 79 {
gustavatmel 1:9c5af431a1f1 80 mbedtls_md_init( &ctx->hmac_ctx );
gustavatmel 1:9c5af431a1f1 81 #if !defined(MBEDTLS_HAVE_TIME)
gustavatmel 1:9c5af431a1f1 82 ctx->serial = 0;
gustavatmel 1:9c5af431a1f1 83 #endif
gustavatmel 1:9c5af431a1f1 84 ctx->timeout = MBEDTLS_SSL_COOKIE_TIMEOUT;
gustavatmel 1:9c5af431a1f1 85
gustavatmel 1:9c5af431a1f1 86 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 87 mbedtls_mutex_init( &ctx->mutex );
gustavatmel 1:9c5af431a1f1 88 #endif
gustavatmel 1:9c5af431a1f1 89 }
gustavatmel 1:9c5af431a1f1 90
gustavatmel 1:9c5af431a1f1 91 void mbedtls_ssl_cookie_set_timeout( mbedtls_ssl_cookie_ctx *ctx, unsigned long delay )
gustavatmel 1:9c5af431a1f1 92 {
gustavatmel 1:9c5af431a1f1 93 ctx->timeout = delay;
gustavatmel 1:9c5af431a1f1 94 }
gustavatmel 1:9c5af431a1f1 95
gustavatmel 1:9c5af431a1f1 96 void mbedtls_ssl_cookie_free( mbedtls_ssl_cookie_ctx *ctx )
gustavatmel 1:9c5af431a1f1 97 {
gustavatmel 1:9c5af431a1f1 98 mbedtls_md_free( &ctx->hmac_ctx );
gustavatmel 1:9c5af431a1f1 99
gustavatmel 1:9c5af431a1f1 100 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 101 mbedtls_mutex_free( &ctx->mutex );
gustavatmel 1:9c5af431a1f1 102 #endif
gustavatmel 1:9c5af431a1f1 103
gustavatmel 1:9c5af431a1f1 104 mbedtls_zeroize( ctx, sizeof( mbedtls_ssl_cookie_ctx ) );
gustavatmel 1:9c5af431a1f1 105 }
gustavatmel 1:9c5af431a1f1 106
gustavatmel 1:9c5af431a1f1 107 int mbedtls_ssl_cookie_setup( mbedtls_ssl_cookie_ctx *ctx,
gustavatmel 1:9c5af431a1f1 108 int (*f_rng)(void *, unsigned char *, size_t),
gustavatmel 1:9c5af431a1f1 109 void *p_rng )
gustavatmel 1:9c5af431a1f1 110 {
gustavatmel 1:9c5af431a1f1 111 int ret;
gustavatmel 1:9c5af431a1f1 112 unsigned char key[COOKIE_MD_OUTLEN];
gustavatmel 1:9c5af431a1f1 113
gustavatmel 1:9c5af431a1f1 114 if( ( ret = f_rng( p_rng, key, sizeof( key ) ) ) != 0 )
gustavatmel 1:9c5af431a1f1 115 return( ret );
gustavatmel 1:9c5af431a1f1 116
gustavatmel 1:9c5af431a1f1 117 ret = mbedtls_md_setup( &ctx->hmac_ctx, mbedtls_md_info_from_type( COOKIE_MD ), 1 );
gustavatmel 1:9c5af431a1f1 118 if( ret != 0 )
gustavatmel 1:9c5af431a1f1 119 return( ret );
gustavatmel 1:9c5af431a1f1 120
gustavatmel 1:9c5af431a1f1 121 ret = mbedtls_md_hmac_starts( &ctx->hmac_ctx, key, sizeof( key ) );
gustavatmel 1:9c5af431a1f1 122 if( ret != 0 )
gustavatmel 1:9c5af431a1f1 123 return( ret );
gustavatmel 1:9c5af431a1f1 124
gustavatmel 1:9c5af431a1f1 125 mbedtls_zeroize( key, sizeof( key ) );
gustavatmel 1:9c5af431a1f1 126
gustavatmel 1:9c5af431a1f1 127 return( 0 );
gustavatmel 1:9c5af431a1f1 128 }
gustavatmel 1:9c5af431a1f1 129
gustavatmel 1:9c5af431a1f1 130 /*
gustavatmel 1:9c5af431a1f1 131 * Generate the HMAC part of a cookie
gustavatmel 1:9c5af431a1f1 132 */
gustavatmel 1:9c5af431a1f1 133 static int ssl_cookie_hmac( mbedtls_md_context_t *hmac_ctx,
gustavatmel 1:9c5af431a1f1 134 const unsigned char time[4],
gustavatmel 1:9c5af431a1f1 135 unsigned char **p, unsigned char *end,
gustavatmel 1:9c5af431a1f1 136 const unsigned char *cli_id, size_t cli_id_len )
gustavatmel 1:9c5af431a1f1 137 {
gustavatmel 1:9c5af431a1f1 138 unsigned char hmac_out[COOKIE_MD_OUTLEN];
gustavatmel 1:9c5af431a1f1 139
gustavatmel 1:9c5af431a1f1 140 if( (size_t)( end - *p ) < COOKIE_HMAC_LEN )
gustavatmel 1:9c5af431a1f1 141 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
gustavatmel 1:9c5af431a1f1 142
gustavatmel 1:9c5af431a1f1 143 if( mbedtls_md_hmac_reset( hmac_ctx ) != 0 ||
gustavatmel 1:9c5af431a1f1 144 mbedtls_md_hmac_update( hmac_ctx, time, 4 ) != 0 ||
gustavatmel 1:9c5af431a1f1 145 mbedtls_md_hmac_update( hmac_ctx, cli_id, cli_id_len ) != 0 ||
gustavatmel 1:9c5af431a1f1 146 mbedtls_md_hmac_finish( hmac_ctx, hmac_out ) != 0 )
gustavatmel 1:9c5af431a1f1 147 {
gustavatmel 1:9c5af431a1f1 148 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
gustavatmel 1:9c5af431a1f1 149 }
gustavatmel 1:9c5af431a1f1 150
gustavatmel 1:9c5af431a1f1 151 memcpy( *p, hmac_out, COOKIE_HMAC_LEN );
gustavatmel 1:9c5af431a1f1 152 *p += COOKIE_HMAC_LEN;
gustavatmel 1:9c5af431a1f1 153
gustavatmel 1:9c5af431a1f1 154 return( 0 );
gustavatmel 1:9c5af431a1f1 155 }
gustavatmel 1:9c5af431a1f1 156
gustavatmel 1:9c5af431a1f1 157 /*
gustavatmel 1:9c5af431a1f1 158 * Generate cookie for DTLS ClientHello verification
gustavatmel 1:9c5af431a1f1 159 */
gustavatmel 1:9c5af431a1f1 160 int mbedtls_ssl_cookie_write( void *p_ctx,
gustavatmel 1:9c5af431a1f1 161 unsigned char **p, unsigned char *end,
gustavatmel 1:9c5af431a1f1 162 const unsigned char *cli_id, size_t cli_id_len )
gustavatmel 1:9c5af431a1f1 163 {
gustavatmel 1:9c5af431a1f1 164 int ret;
gustavatmel 1:9c5af431a1f1 165 mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
gustavatmel 1:9c5af431a1f1 166 unsigned long t;
gustavatmel 1:9c5af431a1f1 167
gustavatmel 1:9c5af431a1f1 168 if( ctx == NULL || cli_id == NULL )
gustavatmel 1:9c5af431a1f1 169 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
gustavatmel 1:9c5af431a1f1 170
gustavatmel 1:9c5af431a1f1 171 if( (size_t)( end - *p ) < COOKIE_LEN )
gustavatmel 1:9c5af431a1f1 172 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
gustavatmel 1:9c5af431a1f1 173
gustavatmel 1:9c5af431a1f1 174 #if defined(MBEDTLS_HAVE_TIME)
gustavatmel 1:9c5af431a1f1 175 t = (unsigned long) mbedtls_time( NULL );
gustavatmel 1:9c5af431a1f1 176 #else
gustavatmel 1:9c5af431a1f1 177 t = ctx->serial++;
gustavatmel 1:9c5af431a1f1 178 #endif
gustavatmel 1:9c5af431a1f1 179
gustavatmel 1:9c5af431a1f1 180 (*p)[0] = (unsigned char)( t >> 24 );
gustavatmel 1:9c5af431a1f1 181 (*p)[1] = (unsigned char)( t >> 16 );
gustavatmel 1:9c5af431a1f1 182 (*p)[2] = (unsigned char)( t >> 8 );
gustavatmel 1:9c5af431a1f1 183 (*p)[3] = (unsigned char)( t );
gustavatmel 1:9c5af431a1f1 184 *p += 4;
gustavatmel 1:9c5af431a1f1 185
gustavatmel 1:9c5af431a1f1 186 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 187 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
gustavatmel 1:9c5af431a1f1 188 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
gustavatmel 1:9c5af431a1f1 189 #endif
gustavatmel 1:9c5af431a1f1 190
gustavatmel 1:9c5af431a1f1 191 ret = ssl_cookie_hmac( &ctx->hmac_ctx, *p - 4,
gustavatmel 1:9c5af431a1f1 192 p, end, cli_id, cli_id_len );
gustavatmel 1:9c5af431a1f1 193
gustavatmel 1:9c5af431a1f1 194 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 195 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
gustavatmel 1:9c5af431a1f1 196 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
gustavatmel 1:9c5af431a1f1 197 MBEDTLS_ERR_THREADING_MUTEX_ERROR );
gustavatmel 1:9c5af431a1f1 198 #endif
gustavatmel 1:9c5af431a1f1 199
gustavatmel 1:9c5af431a1f1 200 return( ret );
gustavatmel 1:9c5af431a1f1 201 }
gustavatmel 1:9c5af431a1f1 202
gustavatmel 1:9c5af431a1f1 203 /*
gustavatmel 1:9c5af431a1f1 204 * Check a cookie
gustavatmel 1:9c5af431a1f1 205 */
gustavatmel 1:9c5af431a1f1 206 int mbedtls_ssl_cookie_check( void *p_ctx,
gustavatmel 1:9c5af431a1f1 207 const unsigned char *cookie, size_t cookie_len,
gustavatmel 1:9c5af431a1f1 208 const unsigned char *cli_id, size_t cli_id_len )
gustavatmel 1:9c5af431a1f1 209 {
gustavatmel 1:9c5af431a1f1 210 unsigned char ref_hmac[COOKIE_HMAC_LEN];
gustavatmel 1:9c5af431a1f1 211 int ret = 0;
gustavatmel 1:9c5af431a1f1 212 unsigned char *p = ref_hmac;
gustavatmel 1:9c5af431a1f1 213 mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
gustavatmel 1:9c5af431a1f1 214 unsigned long cur_time, cookie_time;
gustavatmel 1:9c5af431a1f1 215
gustavatmel 1:9c5af431a1f1 216 if( ctx == NULL || cli_id == NULL )
gustavatmel 1:9c5af431a1f1 217 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
gustavatmel 1:9c5af431a1f1 218
gustavatmel 1:9c5af431a1f1 219 if( cookie_len != COOKIE_LEN )
gustavatmel 1:9c5af431a1f1 220 return( -1 );
gustavatmel 1:9c5af431a1f1 221
gustavatmel 1:9c5af431a1f1 222 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 223 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
gustavatmel 1:9c5af431a1f1 224 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
gustavatmel 1:9c5af431a1f1 225 #endif
gustavatmel 1:9c5af431a1f1 226
gustavatmel 1:9c5af431a1f1 227 if( ssl_cookie_hmac( &ctx->hmac_ctx, cookie,
gustavatmel 1:9c5af431a1f1 228 &p, p + sizeof( ref_hmac ),
gustavatmel 1:9c5af431a1f1 229 cli_id, cli_id_len ) != 0 )
gustavatmel 1:9c5af431a1f1 230 ret = -1;
gustavatmel 1:9c5af431a1f1 231
gustavatmel 1:9c5af431a1f1 232 #if defined(MBEDTLS_THREADING_C)
gustavatmel 1:9c5af431a1f1 233 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
gustavatmel 1:9c5af431a1f1 234 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
gustavatmel 1:9c5af431a1f1 235 MBEDTLS_ERR_THREADING_MUTEX_ERROR );
gustavatmel 1:9c5af431a1f1 236 #endif
gustavatmel 1:9c5af431a1f1 237
gustavatmel 1:9c5af431a1f1 238 if( ret != 0 )
gustavatmel 1:9c5af431a1f1 239 return( ret );
gustavatmel 1:9c5af431a1f1 240
gustavatmel 1:9c5af431a1f1 241 if( mbedtls_ssl_safer_memcmp( cookie + 4, ref_hmac, sizeof( ref_hmac ) ) != 0 )
gustavatmel 1:9c5af431a1f1 242 return( -1 );
gustavatmel 1:9c5af431a1f1 243
gustavatmel 1:9c5af431a1f1 244 #if defined(MBEDTLS_HAVE_TIME)
gustavatmel 1:9c5af431a1f1 245 cur_time = (unsigned long) mbedtls_time( NULL );
gustavatmel 1:9c5af431a1f1 246 #else
gustavatmel 1:9c5af431a1f1 247 cur_time = ctx->serial;
gustavatmel 1:9c5af431a1f1 248 #endif
gustavatmel 1:9c5af431a1f1 249
gustavatmel 1:9c5af431a1f1 250 cookie_time = ( (unsigned long) cookie[0] << 24 ) |
gustavatmel 1:9c5af431a1f1 251 ( (unsigned long) cookie[1] << 16 ) |
gustavatmel 1:9c5af431a1f1 252 ( (unsigned long) cookie[2] << 8 ) |
gustavatmel 1:9c5af431a1f1 253 ( (unsigned long) cookie[3] );
gustavatmel 1:9c5af431a1f1 254
gustavatmel 1:9c5af431a1f1 255 if( ctx->timeout != 0 && cur_time - cookie_time > ctx->timeout )
gustavatmel 1:9c5af431a1f1 256 return( -1 );
gustavatmel 1:9c5af431a1f1 257
gustavatmel 1:9c5af431a1f1 258 return( 0 );
gustavatmel 1:9c5af431a1f1 259 }
gustavatmel 1:9c5af431a1f1 260 #endif /* MBEDTLS_SSL_COOKIE_C */