dll/3rdparty/mbedtls/asn1write.c

   1 /*
   2  * ASN.1 buffer writing functionality
   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 #if !defined(MBEDTLS_CONFIG_FILE)
  25 #include "mbedtls/config.h"
  26 #else
  27 #include MBEDTLS_CONFIG_FILE
  28 #endif
  29
  30 #if defined(MBEDTLS_ASN1_WRITE_C)
  31
  32 #include "mbedtls/asn1write.h"
  33
  34 #include <string.h>
  35
  36 #if defined(MBEDTLS_PLATFORM_C)
  37 #include "mbedtls/platform.h"
  38 #else
  39 #include <stdlib.h>
  40 #define mbedtls_calloc    calloc
  41 #define mbedtls_free       free
  42 #endif
  43
  44 int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start, size_t len )
  45 {
  46     if( len < 0x80 )
  47     {
  48         if( *p - start < 1 )
  49             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
  50
  51         *--(*p) = (unsigned char) len;
  52         return( 1 );
  53     }
  54
  55     if( len <= 0xFF )
  56     {
  57         if( *p - start < 2 )
  58             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
  59
  60         *--(*p) = (unsigned char) len;
  61         *--(*p) = 0x81;
  62         return( 2 );
  63     }
  64
  65     if( len <= 0xFFFF )
  66     {
  67         if( *p - start < 3 )
  68             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
  69
  70         *--(*p) = ( len       ) & 0xFF;
  71         *--(*p) = ( len >>  8 ) & 0xFF;
  72         *--(*p) = 0x82;
  73         return( 3 );
  74     }
  75
  76     if( len <= 0xFFFFFF )
  77     {
  78         if( *p - start < 4 )
  79             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
  80
  81         *--(*p) = ( len       ) & 0xFF;
  82         *--(*p) = ( len >>  8 ) & 0xFF;
  83         *--(*p) = ( len >> 16 ) & 0xFF;
  84         *--(*p) = 0x83;
  85         return( 4 );
  86     }
  87
  88 #if SIZE_MAX > 0xFFFFFFFF
  89     if( len <= 0xFFFFFFFF )
  90 #endif
  91     {
  92         if( *p - start < 5 )
  93             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
  94
  95         *--(*p) = ( len       ) & 0xFF;
  96         *--(*p) = ( len >>  8 ) & 0xFF;
  97         *--(*p) = ( len >> 16 ) & 0xFF;
  98         *--(*p) = ( len >> 24 ) & 0xFF;
  99         *--(*p) = 0x84;
 100         return( 5 );
 101     }
 102
 103 #if SIZE_MAX > 0xFFFFFFFF
 104     return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
 105 #endif
 106 }
 107
 108 int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag )
 109 {
 110     if( *p - start < 1 )
 111         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 112
 113     *--(*p) = tag;
 114
 115     return( 1 );
 116 }
 117
 118 int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start,
 119                            const unsigned char *buf, size_t size )
 120 {
 121     size_t len = 0;
 122
 123     if( *p < start || (size_t)( *p - start ) < size )
 124         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 125
 126     len = size;
 127     (*p) -= len;
 128     memcpy( *p, buf, len );
 129
 130     return( (int) len );
 131 }
 132
 133 #if defined(MBEDTLS_BIGNUM_C)
 134 int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, const mbedtls_mpi *X )
 135 {
 136     int ret;
 137     size_t len = 0;
 138
 139     // Write the MPI
 140     //
 141     len = mbedtls_mpi_size( X );
 142
 143     if( *p < start || (size_t)( *p - start ) < len )
 144         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 145
 146     (*p) -= len;
 147     MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) );
 148
 149     // DER format assumes 2s complement for numbers, so the leftmost bit
 150     // should be 0 for positive numbers and 1 for negative numbers.
 151     //
 152     if( X->s ==1 && **p & 0x80 )
 153     {
 154         if( *p - start < 1 )
 155             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 156
 157         *--(*p) = 0x00;
 158         len += 1;
 159     }
 160
 161     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 162     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
 163
 164     ret = (int) len;
 165
 166 cleanup:
 167     return( ret );
 168 }
 169 #endif /* MBEDTLS_BIGNUM_C */
 170
 171 int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start )
 172 {
 173     int ret;
 174     size_t len = 0;
 175
 176     // Write NULL
 177     //
 178     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) );
 179     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) );
 180
 181     return( (int) len );
 182 }
 183
 184 int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start,
 185                     const char *oid, size_t oid_len )
 186 {
 187     int ret;
 188     size_t len = 0;
 189
 190     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
 191                                   (const unsigned char *) oid, oid_len ) );
 192     MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_len( p, start, len ) );
 193     MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) );
 194
 195     return( (int) len );
 196 }
 197
 198 int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start,
 199                                      const char *oid, size_t oid_len,
 200                                      size_t par_len )
 201 {
 202     int ret;
 203     size_t len = 0;
 204
 205     if( par_len == 0 )
 206         MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) );
 207     else
 208         len += par_len;
 209
 210     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
 211
 212     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 213     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
 214                                        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
 215
 216     return( (int) len );
 217 }
 218
 219 int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolean )
 220 {
 221     int ret;
 222     size_t len = 0;
 223
 224     if( *p - start < 1 )
 225         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 226
 227     *--(*p) = (boolean) ? 255 : 0;
 228     len++;
 229
 230     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 231     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BOOLEAN ) );
 232
 233     return( (int) len );
 234 }
 235
 236 int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
 237 {
 238     int ret;
 239     size_t len = 0;
 240
 241     // DER format assumes 2s complement for numbers, so the leftmost bit
 242     // should be 0 for positive numbers and 1 for negative numbers.
 243     //
 244     if( *p - start < 1 )
 245         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 246
 247     len += 1;
 248     *--(*p) = val;
 249
 250     if( val > 0 && **p & 0x80 )
 251     {
 252         if( *p - start < 1 )
 253             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 254
 255         *--(*p) = 0x00;
 256         len += 1;
 257     }
 258
 259     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 260     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
 261
 262     return( (int) len );
 263 }
 264
 265 int mbedtls_asn1_write_printable_string( unsigned char **p, unsigned char *start,
 266                                  const char *text, size_t text_len )
 267 {
 268     int ret;
 269     size_t len = 0;
 270
 271     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
 272                   (const unsigned char *) text, text_len ) );
 273
 274     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 275     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_PRINTABLE_STRING ) );
 276
 277     return( (int) len );
 278 }
 279
 280 int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
 281                            const char *text, size_t text_len )
 282 {
 283     int ret;
 284     size_t len = 0;
 285
 286     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
 287                   (const unsigned char *) text, text_len ) );
 288
 289     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 290     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_IA5_STRING ) );
 291
 292     return( (int) len );
 293 }
 294
 295 int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
 296                           const unsigned char *buf, size_t bits )
 297 {
 298     int ret;
 299     size_t len = 0;
 300     size_t unused_bits, byte_len;
 301
 302     byte_len = ( bits + 7 ) / 8;
 303     unused_bits = ( byte_len * 8 ) - bits;
 304
 305     if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
 306         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 307
 308     len = byte_len + 1;
 309
 310     /* Write the bitstring. Ensure the unused bits are zeroed */
 311     if( byte_len > 0 )
 312     {
 313         byte_len--;
 314         *--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
 315         ( *p ) -= byte_len;
 316         memcpy( *p, buf, byte_len );
 317     }
 318
 319     /* Write unused bits */
 320     *--( *p ) = (unsigned char)unused_bits;
 321
 322     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 323     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) );
 324
 325     return( (int) len );
 326 }
 327
 328 int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start,
 329                              const unsigned char *buf, size_t size )
 330 {
 331     int ret;
 332     size_t len = 0;
 333
 334     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, size ) );
 335
 336     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
 337     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) );
 338
 339     return( (int) len );
 340 }
 341
 342
 343 /* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
 344  * which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
 345 static mbedtls_asn1_named_data *asn1_find_named_data(
 346                                                mbedtls_asn1_named_data *list,
 347                                                const char *oid, size_t len )
 348 {
 349     while( list != NULL )
 350     {
 351         if( list->oid.len == len &&
 352             memcmp( list->oid.p, oid, len ) == 0 )
 353         {
 354             break;
 355         }
 356
 357         list = list->next;
 358     }
 359
 360     return( list );
 361 }
 362
 363 mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
 364                                         mbedtls_asn1_named_data **head,
 365                                         const char *oid, size_t oid_len,
 366                                         const unsigned char *val,
 367                                         size_t val_len )
 368 {
 369     mbedtls_asn1_named_data *cur;
 370
 371     if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
 372     {
 373         // Add new entry if not present yet based on OID
 374         //
 375         cur = (mbedtls_asn1_named_data*)mbedtls_calloc( 1,
 376                                             sizeof(mbedtls_asn1_named_data) );
 377         if( cur == NULL )
 378             return( NULL );
 379
 380         cur->oid.len = oid_len;
 381         cur->oid.p = mbedtls_calloc( 1, oid_len );
 382         if( cur->oid.p == NULL )
 383         {
 384             mbedtls_free( cur );
 385             return( NULL );
 386         }
 387
 388         memcpy( cur->oid.p, oid, oid_len );
 389
 390         cur->val.len = val_len;
 391         cur->val.p = mbedtls_calloc( 1, val_len );
 392         if( cur->val.p == NULL )
 393         {
 394             mbedtls_free( cur->oid.p );
 395             mbedtls_free( cur );
 396             return( NULL );
 397         }
 398
 399         cur->next = *head;
 400         *head = cur;
 401     }
 402     else if( cur->val.len < val_len )
 403     {
 404         /*
 405          * Enlarge existing value buffer if needed
 406          * Preserve old data until the allocation succeeded, to leave list in
 407          * a consistent state in case allocation fails.
 408          */
 409         void *p = mbedtls_calloc( 1, val_len );
 410         if( p == NULL )
 411             return( NULL );
 412
 413         mbedtls_free( cur->val.p );
 414         cur->val.p = p;
 415         cur->val.len = val_len;
 416     }
 417
 418     if( val != NULL )
 419         memcpy( cur->val.p, val, val_len );
 420
 421     return( cur );
 422 }
 423 #endif /* MBEDTLS_ASN1_WRITE_C */