2 * ASN.1 buffer writing functionality
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
19 * This file is part of mbed TLS (https://tls.mbed.org)
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
25 #include MBEDTLS_CONFIG_FILE
28 #if defined(MBEDTLS_ASN1_WRITE_C)
30 #include "mbedtls/asn1write.h"
34 #if defined(MBEDTLS_PLATFORM_C)
35 #include "mbedtls/platform.h"
38 #define mbedtls_calloc calloc
39 #define mbedtls_free free
42 int mbedtls_asn1_write_len( unsigned char **p
, unsigned char *start
, size_t len
)
47 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
49 *--(*p
) = (unsigned char) len
;
56 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
58 *--(*p
) = (unsigned char) len
;
64 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
66 // We assume we never have lengths larger than 65535 bytes
69 *--(*p
) = ( len
/ 256 ) % 256;
75 int mbedtls_asn1_write_tag( unsigned char **p
, unsigned char *start
, unsigned char tag
)
78 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
85 int mbedtls_asn1_write_raw_buffer( unsigned char **p
, unsigned char *start
,
86 const unsigned char *buf
, size_t size
)
90 if( *p
< start
|| (size_t)( *p
- start
) < size
)
91 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
95 memcpy( *p
, buf
, len
);
100 #if defined(MBEDTLS_BIGNUM_C)
101 int mbedtls_asn1_write_mpi( unsigned char **p
, unsigned char *start
, const mbedtls_mpi
*X
)
108 len
= mbedtls_mpi_size( X
);
110 if( *p
< start
|| (size_t)( *p
- start
) < len
)
111 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
114 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X
, *p
, len
) );
116 // DER format assumes 2s complement for numbers, so the leftmost bit
117 // should be 0 for positive numbers and 1 for negative numbers.
119 if( X
->s
==1 && **p
& 0x80 )
122 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
128 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
129 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_INTEGER
) );
136 #endif /* MBEDTLS_BIGNUM_C */
138 int mbedtls_asn1_write_null( unsigned char **p
, unsigned char *start
)
145 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, 0) );
146 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_NULL
) );
151 int mbedtls_asn1_write_oid( unsigned char **p
, unsigned char *start
,
152 const char *oid
, size_t oid_len
)
157 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_raw_buffer( p
, start
,
158 (const unsigned char *) oid
, oid_len
) );
159 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
160 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_OID
) );
165 int mbedtls_asn1_write_algorithm_identifier( unsigned char **p
, unsigned char *start
,
166 const char *oid
, size_t oid_len
,
173 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_null( p
, start
) );
177 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_oid( p
, start
, oid
, oid_len
) );
179 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
180 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
,
181 MBEDTLS_ASN1_CONSTRUCTED
| MBEDTLS_ASN1_SEQUENCE
) );
186 int mbedtls_asn1_write_bool( unsigned char **p
, unsigned char *start
, int boolean
)
192 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
194 *--(*p
) = (boolean
) ? 255 : 0;
197 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
198 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_BOOLEAN
) );
203 int mbedtls_asn1_write_int( unsigned char **p
, unsigned char *start
, int val
)
208 // TODO negative values and values larger than 128
209 // DER format assumes 2s complement for numbers, so the leftmost bit
210 // should be 0 for positive numbers and 1 for negative numbers.
213 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
218 if( val
> 0 && **p
& 0x80 )
221 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
227 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
228 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_INTEGER
) );
233 int mbedtls_asn1_write_printable_string( unsigned char **p
, unsigned char *start
,
234 const char *text
, size_t text_len
)
239 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_raw_buffer( p
, start
,
240 (const unsigned char *) text
, text_len
) );
242 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
243 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_PRINTABLE_STRING
) );
248 int mbedtls_asn1_write_ia5_string( unsigned char **p
, unsigned char *start
,
249 const char *text
, size_t text_len
)
254 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_raw_buffer( p
, start
,
255 (const unsigned char *) text
, text_len
) );
257 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
258 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_IA5_STRING
) );
263 int mbedtls_asn1_write_bitstring( unsigned char **p
, unsigned char *start
,
264 const unsigned char *buf
, size_t bits
)
267 size_t len
= 0, size
;
269 size
= ( bits
/ 8 ) + ( ( bits
% 8 ) ? 1 : 0 );
271 // Calculate byte length
273 if( *p
< start
|| (size_t)( *p
- start
) < size
+ 1 )
274 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
);
278 memcpy( *p
, buf
, size
);
282 *--(*p
) = (unsigned char) (size
* 8 - bits
);
284 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
285 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_BIT_STRING
) );
290 int mbedtls_asn1_write_octet_string( unsigned char **p
, unsigned char *start
,
291 const unsigned char *buf
, size_t size
)
296 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_raw_buffer( p
, start
, buf
, size
) );
298 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_len( p
, start
, len
) );
299 MBEDTLS_ASN1_CHK_ADD( len
, mbedtls_asn1_write_tag( p
, start
, MBEDTLS_ASN1_OCTET_STRING
) );
304 mbedtls_asn1_named_data
*mbedtls_asn1_store_named_data( mbedtls_asn1_named_data
**head
,
305 const char *oid
, size_t oid_len
,
306 const unsigned char *val
,
309 mbedtls_asn1_named_data
*cur
;
311 if( ( cur
= mbedtls_asn1_find_named_data( *head
, oid
, oid_len
) ) == NULL
)
313 // Add new entry if not present yet based on OID
315 if( ( cur
= mbedtls_calloc( 1, sizeof(mbedtls_asn1_named_data
) ) ) == NULL
)
318 cur
->oid
.len
= oid_len
;
319 cur
->oid
.p
= mbedtls_calloc( 1, oid_len
);
320 if( cur
->oid
.p
== NULL
)
326 memcpy( cur
->oid
.p
, oid
, oid_len
);
328 cur
->val
.len
= val_len
;
329 cur
->val
.p
= mbedtls_calloc( 1, val_len
);
330 if( cur
->val
.p
== NULL
)
332 mbedtls_free( cur
->oid
.p
);
340 else if( cur
->val
.len
< val_len
)
343 * Enlarge existing value buffer if needed
344 * Preserve old data until the allocation succeeded, to leave list in
345 * a consistent state in case allocation fails.
347 void *p
= mbedtls_calloc( 1, val_len
);
351 mbedtls_free( cur
->val
.p
);
353 cur
->val
.len
= val_len
;
357 memcpy( cur
->val
.p
, val
, val_len
);
361 #endif /* MBEDTLS_ASN1_WRITE_C */