reactos/dll/3rdparty/mbedtls/ssl_cookie.c

   1 /*
   2  *  DTLS cookie callbacks implementation
   3  *
   4  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
   5  *  SPDX-License-Identifier: GPL-2.0
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License along
  18  *  with this program; if not, write to the Free Software Foundation, Inc.,
  19  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  *  This file is part of mbed TLS (https://tls.mbed.org)
  22  */
  23 /*
  24  * These session callbacks use a simple chained list
  25  * to store and retrieve the session information.
  26  */
  27
  28 #if !defined(MBEDTLS_CONFIG_FILE)
  29 #include "mbedtls/config.h"
  30 #else
  31 #include MBEDTLS_CONFIG_FILE
  32 #endif
  33
  34 #if defined(MBEDTLS_SSL_COOKIE_C)
  35
  36 #if defined(MBEDTLS_PLATFORM_C)
  37 #include "mbedtls/platform.h"
  38 #else
  39 #define mbedtls_calloc    calloc
  40 #define mbedtls_free      free
  41 #define mbedtls_time      time
  42 #define mbedtls_time_t    time_t
  43 #endif
  44
  45 #include "mbedtls/ssl_cookie.h"
  46 #include "mbedtls/ssl_internal.h"
  47
  48 #include <string.h>
  49
  50 /* Implementation that should never be optimized out by the compiler */
  51 static void mbedtls_zeroize( void *v, size_t n ) {
  52     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
  53 }
  54
  55 /*
  56  * If DTLS is in use, then at least one of SHA-1, SHA-256, SHA-512 is
  57  * available. Try SHA-256 first, 512 wastes resources since we need to stay
  58  * with max 32 bytes of cookie for DTLS 1.0
  59  */
  60 #if defined(MBEDTLS_SHA256_C)
  61 #define COOKIE_MD           MBEDTLS_MD_SHA224
  62 #define COOKIE_MD_OUTLEN    32
  63 #define COOKIE_HMAC_LEN     28
  64 #elif defined(MBEDTLS_SHA512_C)
  65 #define COOKIE_MD           MBEDTLS_MD_SHA384
  66 #define COOKIE_MD_OUTLEN    48
  67 #define COOKIE_HMAC_LEN     28
  68 #elif defined(MBEDTLS_SHA1_C)
  69 #define COOKIE_MD           MBEDTLS_MD_SHA1
  70 #define COOKIE_MD_OUTLEN    20
  71 #define COOKIE_HMAC_LEN     20
  72 #else
  73 #error "DTLS hello verify needs SHA-1 or SHA-2"
  74 #endif
  75
  76 /*
  77  * Cookies are formed of a 4-bytes timestamp (or serial number) and
  78  * an HMAC of timestemp and client ID.
  79  */
  80 #define COOKIE_LEN      ( 4 + COOKIE_HMAC_LEN )
  81
  82 void mbedtls_ssl_cookie_init( mbedtls_ssl_cookie_ctx *ctx )
  83 {
  84     mbedtls_md_init( &ctx->hmac_ctx );
  85 #if !defined(MBEDTLS_HAVE_TIME)
  86     ctx->serial = 0;
  87 #endif
  88     ctx->timeout = MBEDTLS_SSL_COOKIE_TIMEOUT;
  89
  90 #if defined(MBEDTLS_THREADING_C)
  91     mbedtls_mutex_init( &ctx->mutex );
  92 #endif
  93 }
  94
  95 void mbedtls_ssl_cookie_set_timeout( mbedtls_ssl_cookie_ctx *ctx, unsigned long delay )
  96 {
  97     ctx->timeout = delay;
  98 }
  99
 100 void mbedtls_ssl_cookie_free( mbedtls_ssl_cookie_ctx *ctx )
 101 {
 102     mbedtls_md_free( &ctx->hmac_ctx );
 103
 104 #if defined(MBEDTLS_THREADING_C)
 105     mbedtls_mutex_init( &ctx->mutex );
 106 #endif
 107
 108     mbedtls_zeroize( ctx, sizeof( mbedtls_ssl_cookie_ctx ) );
 109 }
 110
 111 int mbedtls_ssl_cookie_setup( mbedtls_ssl_cookie_ctx *ctx,
 112                       int (*f_rng)(void *, unsigned char *, size_t),
 113                       void *p_rng )
 114 {
 115     int ret;
 116     unsigned char key[COOKIE_MD_OUTLEN];
 117
 118     if( ( ret = f_rng( p_rng, key, sizeof( key ) ) ) != 0 )
 119         return( ret );
 120
 121     ret = mbedtls_md_setup( &ctx->hmac_ctx, mbedtls_md_info_from_type( COOKIE_MD ), 1 );
 122     if( ret != 0 )
 123         return( ret );
 124
 125     ret = mbedtls_md_hmac_starts( &ctx->hmac_ctx, key, sizeof( key ) );
 126     if( ret != 0 )
 127         return( ret );
 128
 129     mbedtls_zeroize( key, sizeof( key ) );
 130
 131     return( 0 );
 132 }
 133
 134 /*
 135  * Generate the HMAC part of a cookie
 136  */
 137 static int ssl_cookie_hmac( mbedtls_md_context_t *hmac_ctx,
 138                             const unsigned char time[4],
 139                             unsigned char **p, unsigned char *end,
 140                             const unsigned char *cli_id, size_t cli_id_len )
 141 {
 142     unsigned char hmac_out[COOKIE_MD_OUTLEN];
 143
 144     if( (size_t)( end - *p ) < COOKIE_HMAC_LEN )
 145         return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
 146
 147     if( mbedtls_md_hmac_reset(  hmac_ctx ) != 0 ||
 148         mbedtls_md_hmac_update( hmac_ctx, time, 4 ) != 0 ||
 149         mbedtls_md_hmac_update( hmac_ctx, cli_id, cli_id_len ) != 0 ||
 150         mbedtls_md_hmac_finish( hmac_ctx, hmac_out ) != 0 )
 151     {
 152         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 153     }
 154
 155     memcpy( *p, hmac_out, COOKIE_HMAC_LEN );
 156     *p += COOKIE_HMAC_LEN;
 157
 158     return( 0 );
 159 }
 160
 161 /*
 162  * Generate cookie for DTLS ClientHello verification
 163  */
 164 int mbedtls_ssl_cookie_write( void *p_ctx,
 165                       unsigned char **p, unsigned char *end,
 166                       const unsigned char *cli_id, size_t cli_id_len )
 167 {
 168     int ret;
 169     mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
 170     unsigned long t;
 171
 172     if( ctx == NULL || cli_id == NULL )
 173         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 174
 175     if( (size_t)( end - *p ) < COOKIE_LEN )
 176         return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
 177
 178 #if defined(MBEDTLS_HAVE_TIME)
 179     t = (unsigned long) mbedtls_time( NULL );
 180 #else
 181     t = ctx->serial++;
 182 #endif
 183
 184     (*p)[0] = (unsigned char)( t >> 24 );
 185     (*p)[1] = (unsigned char)( t >> 16 );
 186     (*p)[2] = (unsigned char)( t >>  8 );
 187     (*p)[3] = (unsigned char)( t       );
 188     *p += 4;
 189
 190 #if defined(MBEDTLS_THREADING_C)
 191     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
 192         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
 193 #endif
 194
 195     ret = ssl_cookie_hmac( &ctx->hmac_ctx, *p - 4,
 196                            p, end, cli_id, cli_id_len );
 197
 198 #if defined(MBEDTLS_THREADING_C)
 199     if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
 200         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
 201                 MBEDTLS_ERR_THREADING_MUTEX_ERROR );
 202 #endif
 203
 204     return( ret );
 205 }
 206
 207 /*
 208  * Check a cookie
 209  */
 210 int mbedtls_ssl_cookie_check( void *p_ctx,
 211                       const unsigned char *cookie, size_t cookie_len,
 212                       const unsigned char *cli_id, size_t cli_id_len )
 213 {
 214     unsigned char ref_hmac[COOKIE_HMAC_LEN];
 215     int ret = 0;
 216     unsigned char *p = ref_hmac;
 217     mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
 218     unsigned long cur_time, cookie_time;
 219
 220     if( ctx == NULL || cli_id == NULL )
 221         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 222
 223     if( cookie_len != COOKIE_LEN )
 224         return( -1 );
 225
 226 #if defined(MBEDTLS_THREADING_C)
 227     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
 228         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
 229 #endif
 230
 231     if( ssl_cookie_hmac( &ctx->hmac_ctx, cookie,
 232                          &p, p + sizeof( ref_hmac ),
 233                          cli_id, cli_id_len ) != 0 )
 234         ret = -1;
 235
 236 #if defined(MBEDTLS_THREADING_C)
 237     if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
 238         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
 239                 MBEDTLS_ERR_THREADING_MUTEX_ERROR );
 240 #endif
 241
 242     if( ret != 0 )
 243         return( ret );
 244
 245     if( mbedtls_ssl_safer_memcmp( cookie + 4, ref_hmac, sizeof( ref_hmac ) ) != 0 )
 246         return( -1 );
 247
 248 #if defined(MBEDTLS_HAVE_TIME)
 249     cur_time = (unsigned long) mbedtls_time( NULL );
 250 #else
 251     cur_time = ctx->serial;
 252 #endif
 253
 254     cookie_time = ( (unsigned long) cookie[0] << 24 ) |
 255                   ( (unsigned long) cookie[1] << 16 ) |
 256                   ( (unsigned long) cookie[2] <<  8 ) |
 257                   ( (unsigned long) cookie[3]       );
 258
 259     if( ctx->timeout != 0 && cur_time - cookie_time > ctx->timeout )
 260         return( -1 );
 261
 262     return( 0 );
 263 }
 264 #endif /* MBEDTLS_SSL_COOKIE_C */