mbed TLS Build
Dependents: Encypting_Funcional
asn1write.c
00001 /* 00002 * ASN.1 buffer writing functionality 00003 * 00004 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 00005 * SPDX-License-Identifier: Apache-2.0 00006 * 00007 * Licensed under the Apache License, Version 2.0 (the "License"); you may 00008 * not use this file except in compliance with the License. 00009 * You may obtain a copy of the License at 00010 * 00011 * http://www.apache.org/licenses/LICENSE-2.0 00012 * 00013 * Unless required by applicable law or agreed to in writing, software 00014 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 00015 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00016 * See the License for the specific language governing permissions and 00017 * limitations under the License. 00018 * 00019 * This file is part of mbed TLS (https://tls.mbed.org) 00020 */ 00021 00022 #if !defined(MBEDTLS_CONFIG_FILE) 00023 #include "mbedtls/config.h" 00024 #else 00025 #include MBEDTLS_CONFIG_FILE 00026 #endif 00027 00028 #if defined(MBEDTLS_ASN1_WRITE_C) 00029 00030 #include "mbedtls/asn1write.h" 00031 00032 #include <string.h> 00033 00034 #if defined(MBEDTLS_PLATFORM_C) 00035 #include "mbedtls/platform.h" 00036 #else 00037 #include <stdlib.h> 00038 #define mbedtls_calloc calloc 00039 #define mbedtls_free free 00040 #endif 00041 00042 int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start, size_t len ) 00043 { 00044 if( len < 0x80 ) 00045 { 00046 if( *p - start < 1 ) 00047 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00048 00049 *--(*p) = (unsigned char) len; 00050 return( 1 ); 00051 } 00052 00053 if( len <= 0xFF ) 00054 { 00055 if( *p - start < 2 ) 00056 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00057 00058 *--(*p) = (unsigned char) len; 00059 *--(*p) = 0x81; 00060 return( 2 ); 00061 } 00062 00063 if( len <= 0xFFFF ) 00064 { 00065 if( *p - start < 3 ) 00066 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00067 00068 *--(*p) = ( len ) & 0xFF; 00069 *--(*p) = ( len >> 8 ) & 0xFF; 00070 *--(*p) = 0x82; 00071 return( 3 ); 00072 } 00073 00074 if( len <= 0xFFFFFF ) 00075 { 00076 if( *p - start < 4 ) 00077 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00078 00079 *--(*p) = ( len ) & 0xFF; 00080 *--(*p) = ( len >> 8 ) & 0xFF; 00081 *--(*p) = ( len >> 16 ) & 0xFF; 00082 *--(*p) = 0x83; 00083 return( 4 ); 00084 } 00085 00086 if( len <= 0xFFFFFFFF ) 00087 { 00088 if( *p - start < 5 ) 00089 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00090 00091 *--(*p) = ( len ) & 0xFF; 00092 *--(*p) = ( len >> 8 ) & 0xFF; 00093 *--(*p) = ( len >> 16 ) & 0xFF; 00094 *--(*p) = ( len >> 24 ) & 0xFF; 00095 *--(*p) = 0x84; 00096 return( 5 ); 00097 } 00098 00099 return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); 00100 } 00101 00102 int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag ) 00103 { 00104 if( *p - start < 1 ) 00105 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00106 00107 *--(*p) = tag; 00108 00109 return( 1 ); 00110 } 00111 00112 int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start, 00113 const unsigned char *buf, size_t size ) 00114 { 00115 size_t len = 0; 00116 00117 if( *p < start || (size_t)( *p - start ) < size ) 00118 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00119 00120 len = size; 00121 (*p) -= len; 00122 memcpy( *p, buf, len ); 00123 00124 return( (int) len ); 00125 } 00126 00127 #if defined(MBEDTLS_BIGNUM_C) 00128 int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, const mbedtls_mpi *X ) 00129 { 00130 int ret; 00131 size_t len = 0; 00132 00133 // Write the MPI 00134 // 00135 len = mbedtls_mpi_size( X ); 00136 00137 if( *p < start || (size_t)( *p - start ) < len ) 00138 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00139 00140 (*p) -= len; 00141 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) ); 00142 00143 // DER format assumes 2s complement for numbers, so the leftmost bit 00144 // should be 0 for positive numbers and 1 for negative numbers. 00145 // 00146 if( X->s ==1 && **p & 0x80 ) 00147 { 00148 if( *p - start < 1 ) 00149 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00150 00151 *--(*p) = 0x00; 00152 len += 1; 00153 } 00154 00155 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00156 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) ); 00157 00158 ret = (int) len; 00159 00160 cleanup: 00161 return( ret ); 00162 } 00163 #endif /* MBEDTLS_BIGNUM_C */ 00164 00165 int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start ) 00166 { 00167 int ret; 00168 size_t len = 0; 00169 00170 // Write NULL 00171 // 00172 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) ); 00173 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) ); 00174 00175 return( (int) len ); 00176 } 00177 00178 int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start, 00179 const char *oid, size_t oid_len ) 00180 { 00181 int ret; 00182 size_t len = 0; 00183 00184 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, 00185 (const unsigned char *) oid, oid_len ) ); 00186 MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_len( p, start, len ) ); 00187 MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) ); 00188 00189 return( (int) len ); 00190 } 00191 00192 int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start, 00193 const char *oid, size_t oid_len, 00194 size_t par_len ) 00195 { 00196 int ret; 00197 size_t len = 0; 00198 00199 if( par_len == 0 ) 00200 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) ); 00201 else 00202 len += par_len; 00203 00204 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) ); 00205 00206 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00207 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, 00208 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); 00209 00210 return( (int) len ); 00211 } 00212 00213 int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolean ) 00214 { 00215 int ret; 00216 size_t len = 0; 00217 00218 if( *p - start < 1 ) 00219 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00220 00221 *--(*p) = (boolean) ? 255 : 0; 00222 len++; 00223 00224 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00225 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BOOLEAN ) ); 00226 00227 return( (int) len ); 00228 } 00229 00230 int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val ) 00231 { 00232 int ret; 00233 size_t len = 0; 00234 00235 // TODO negative values and values larger than 128 00236 // DER format assumes 2s complement for numbers, so the leftmost bit 00237 // should be 0 for positive numbers and 1 for negative numbers. 00238 // 00239 if( *p - start < 1 ) 00240 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00241 00242 len += 1; 00243 *--(*p) = val; 00244 00245 if( val > 0 && **p & 0x80 ) 00246 { 00247 if( *p - start < 1 ) 00248 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00249 00250 *--(*p) = 0x00; 00251 len += 1; 00252 } 00253 00254 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00255 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) ); 00256 00257 return( (int) len ); 00258 } 00259 00260 int mbedtls_asn1_write_printable_string( unsigned char **p, unsigned char *start, 00261 const char *text, size_t text_len ) 00262 { 00263 int ret; 00264 size_t len = 0; 00265 00266 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, 00267 (const unsigned char *) text, text_len ) ); 00268 00269 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00270 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_PRINTABLE_STRING ) ); 00271 00272 return( (int) len ); 00273 } 00274 00275 int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start, 00276 const char *text, size_t text_len ) 00277 { 00278 int ret; 00279 size_t len = 0; 00280 00281 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, 00282 (const unsigned char *) text, text_len ) ); 00283 00284 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00285 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_IA5_STRING ) ); 00286 00287 return( (int) len ); 00288 } 00289 00290 int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start, 00291 const unsigned char *buf, size_t bits ) 00292 { 00293 int ret; 00294 size_t len = 0, size; 00295 00296 size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 ); 00297 00298 // Calculate byte length 00299 // 00300 if( *p < start || (size_t)( *p - start ) < size + 1 ) 00301 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 00302 00303 len = size + 1; 00304 (*p) -= size; 00305 memcpy( *p, buf, size ); 00306 00307 // Write unused bits 00308 // 00309 *--(*p) = (unsigned char) (size * 8 - bits); 00310 00311 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00312 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) ); 00313 00314 return( (int) len ); 00315 } 00316 00317 int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start, 00318 const unsigned char *buf, size_t size ) 00319 { 00320 int ret; 00321 size_t len = 0; 00322 00323 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, size ) ); 00324 00325 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 00326 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) ); 00327 00328 return( (int) len ); 00329 } 00330 00331 mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data **head, 00332 const char *oid, size_t oid_len, 00333 const unsigned char *val, 00334 size_t val_len ) 00335 { 00336 mbedtls_asn1_named_data *cur; 00337 00338 if( ( cur = mbedtls_asn1_find_named_data( *head, oid, oid_len ) ) == NULL ) 00339 { 00340 // Add new entry if not present yet based on OID 00341 // 00342 cur = (mbedtls_asn1_named_data*)mbedtls_calloc( 1, 00343 sizeof(mbedtls_asn1_named_data) ); 00344 if( cur == NULL ) 00345 return( NULL ); 00346 00347 cur->oid.len = oid_len; 00348 cur->oid.p = mbedtls_calloc( 1, oid_len ); 00349 if( cur->oid.p == NULL ) 00350 { 00351 mbedtls_free( cur ); 00352 return( NULL ); 00353 } 00354 00355 memcpy( cur->oid.p, oid, oid_len ); 00356 00357 cur->val.len = val_len; 00358 cur->val.p = mbedtls_calloc( 1, val_len ); 00359 if( cur->val.p == NULL ) 00360 { 00361 mbedtls_free( cur->oid.p ); 00362 mbedtls_free( cur ); 00363 return( NULL ); 00364 } 00365 00366 cur->next = *head; 00367 *head = cur; 00368 } 00369 else if( cur->val.len < val_len ) 00370 { 00371 /* 00372 * Enlarge existing value buffer if needed 00373 * Preserve old data until the allocation succeeded, to leave list in 00374 * a consistent state in case allocation fails. 00375 */ 00376 void *p = mbedtls_calloc( 1, val_len ); 00377 if( p == NULL ) 00378 return( NULL ); 00379 00380 mbedtls_free( cur->val.p ); 00381 cur->val.p = p; 00382 cur->val.len = val_len; 00383 } 00384 00385 if( val != NULL ) 00386 memcpy( cur->val.p, val, val_len ); 00387 00388 return( cur ); 00389 } 00390 #endif /* MBEDTLS_ASN1_WRITE_C */
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