yuzu-emu/mbedtls
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
mbedtls/library/asn1write.c
Gilles Peskine 945b23c46f Include platform.h unconditionally: automatic part 
We used to include platform.h only when MBEDTLS_PLATFORM_C was enabled, and
to define ad hoc replacements for mbedtls_xxx functions on a case-by-case
basis when MBEDTLS_PLATFORM_C was disabled. The only reason for this
complication was to allow building individual source modules without copying
platform.h. This is not something we support or recommend anymore, so get
rid of the complication: include platform.h unconditionally.

There should be no change in behavior since just including the header should
not change the behavior of a program.

This commit replaces most occurrences of conditional inclusion of
platform.h, using the following code:

```
perl -i -0777 -pe 's!#if.*\n#include "mbedtls/platform.h"\n(#else.*\n(#define (mbedtls|MBEDTLS)_.*\n|#include <(stdarg|stddef|stdio|stdlib|string|time)\.h>\n)*)?#endif.*!#include "mbedtls/platform.h"!mg' $(git grep -l '#include "mbedtls/platform.h"')
```

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2022-09-15 20:33:07 +02:00

479 lines
14 KiB
C
Raw Blame History

/*
* ASN.1 buffer writing functionality
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_ASN1_WRITE_C)
#include "mbedtls/asn1write.h"
#include "mbedtls/error.h"
#include <string.h>
#include "mbedtls/platform.h"
int mbedtls_asn1_write_len( unsigned char **p, const unsigned char *start, size_t len )
{
if( len < 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = (unsigned char) len;
return( 1 );
}
if( len <= 0xFF )
{
if( *p - start < 2 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = (unsigned char) len;
*--(*p) = 0x81;
return( 2 );
}
if( len <= 0xFFFF )
{
if( *p - start < 3 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = MBEDTLS_BYTE_0( len );
*--(*p) = MBEDTLS_BYTE_1( len );
*--(*p) = 0x82;
return( 3 );
}
if( len <= 0xFFFFFF )
{
if( *p - start < 4 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = MBEDTLS_BYTE_0( len );
*--(*p) = MBEDTLS_BYTE_1( len );
*--(*p) = MBEDTLS_BYTE_2( len );
*--(*p) = 0x83;
return( 4 );
}
#if SIZE_MAX > 0xFFFFFFFF
if( len <= 0xFFFFFFFF )
#endif
{
if( *p - start < 5 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = MBEDTLS_BYTE_0( len );
*--(*p) = MBEDTLS_BYTE_1( len );
*--(*p) = MBEDTLS_BYTE_2( len );
*--(*p) = MBEDTLS_BYTE_3( len );
*--(*p) = 0x84;
return( 5 );
}
#if SIZE_MAX > 0xFFFFFFFF
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
#endif
}
int mbedtls_asn1_write_tag( unsigned char **p, const unsigned char *start, unsigned char tag )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = tag;
return( 1 );
}
int mbedtls_asn1_write_raw_buffer( unsigned char **p, const unsigned char *start,
const unsigned char *buf, size_t size )
{
size_t len = 0;
if( *p < start || (size_t)( *p - start ) < size )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = size;
(*p) -= len;
memcpy( *p, buf, len );
return( (int) len );
}
#if defined(MBEDTLS_BIGNUM_C)
int mbedtls_asn1_write_mpi( unsigned char **p, const unsigned char *start, const mbedtls_mpi *X )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
// Write the MPI
//
len = mbedtls_mpi_size( X );
/* DER represents 0 with a sign bit (0=nonnegative) and 7 value bits, not
* as 0 digits. We need to end up with 020100, not with 0200. */
if( len == 0 )
len = 1;
if( *p < start || (size_t)( *p - start ) < len )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
(*p) -= len;
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) );
// DER format assumes 2s complement for numbers, so the leftmost bit
// should be 0 for positive numbers and 1 for negative numbers.
//
if( X->s ==1 && **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
ret = (int) len;
cleanup:
return( ret );
}
#endif /* MBEDTLS_BIGNUM_C */
int mbedtls_asn1_write_null( unsigned char **p, const unsigned char *start )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
// Write NULL
//
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) );
return( (int) len );
}
int mbedtls_asn1_write_oid( unsigned char **p, const unsigned char *start,
const char *oid, size_t oid_len )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
(const unsigned char *) oid, oid_len ) );
MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) );
return( (int) len );
}
int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, const unsigned char *start,
const char *oid, size_t oid_len,
size_t par_len )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
if( par_len == 0 )
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) );
else
len += par_len;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
int mbedtls_asn1_write_bool( unsigned char **p, const unsigned char *start, int boolean )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = (boolean) ? 255 : 0;
len++;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BOOLEAN ) );
return( (int) len );
}
static int asn1_write_tagged_int( unsigned char **p, const unsigned char *start, int val, int tag )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
do
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len += 1;
*--(*p) = val & 0xff;
val >>= 8;
}
while( val > 0 );
if( **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, tag ) );
return( (int) len );
}
int mbedtls_asn1_write_int( unsigned char **p, const unsigned char *start, int val )
{
return( asn1_write_tagged_int( p, start, val, MBEDTLS_ASN1_INTEGER ) );
}
int mbedtls_asn1_write_enum( unsigned char **p, const unsigned char *start, int val )
{
return( asn1_write_tagged_int( p, start, val, MBEDTLS_ASN1_ENUMERATED ) );
}
int mbedtls_asn1_write_tagged_string( unsigned char **p, const unsigned char *start, int tag,
const char *text, size_t text_len )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
(const unsigned char *) text, text_len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, tag ) );
return( (int) len );
}
int mbedtls_asn1_write_utf8_string( unsigned char **p, const unsigned char *start,
const char *text, size_t text_len )
{
return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_UTF8_STRING, text, text_len) );
}
int mbedtls_asn1_write_printable_string( unsigned char **p, const unsigned char *start,
const char *text, size_t text_len )
{
return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_PRINTABLE_STRING, text, text_len) );
}
int mbedtls_asn1_write_ia5_string( unsigned char **p, const unsigned char *start,
const char *text, size_t text_len )
{
return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len) );
}
int mbedtls_asn1_write_named_bitstring( unsigned char **p,
const unsigned char *start,
const unsigned char *buf,
size_t bits )
{
size_t unused_bits, byte_len;
const unsigned char *cur_byte;
unsigned char cur_byte_shifted;
unsigned char bit;
byte_len = ( bits + 7 ) / 8;
unused_bits = ( byte_len * 8 ) - bits;
/*
* Named bitstrings require that trailing 0s are excluded in the encoding
* of the bitstring. Trailing 0s are considered part of the 'unused' bits
* when encoding this value in the first content octet
*/
if( bits != 0 )
{
cur_byte = buf + byte_len - 1;
cur_byte_shifted = *cur_byte >> unused_bits;
for( ; ; )
{
bit = cur_byte_shifted & 0x1;
cur_byte_shifted >>= 1;
if( bit != 0 )
break;
bits--;
if( bits == 0 )
break;
if( bits % 8 == 0 )
cur_byte_shifted = *--cur_byte;
}
}
return( mbedtls_asn1_write_bitstring( p, start, buf, bits ) );
}
int mbedtls_asn1_write_bitstring( unsigned char **p, const unsigned char *start,
const unsigned char *buf, size_t bits )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
size_t unused_bits, byte_len;
byte_len = ( bits + 7 ) / 8;
unused_bits = ( byte_len * 8 ) - bits;
if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = byte_len + 1;
/* Write the bitstring. Ensure the unused bits are zeroed */
if( byte_len > 0 )
{
byte_len--;
*--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
( *p ) -= byte_len;
memcpy( *p, buf, byte_len );
}
/* Write unused bits */
*--( *p ) = (unsigned char)unused_bits;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) );
return( (int) len );
}
int mbedtls_asn1_write_octet_string( unsigned char **p, const unsigned char *start,
const unsigned char *buf, size_t size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, size ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) );
return( (int) len );
}
/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
* which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
static mbedtls_asn1_named_data *asn1_find_named_data(
mbedtls_asn1_named_data *list,
const char *oid, size_t len )
{
while( list != NULL )
{
if( list->oid.len == len &&
memcmp( list->oid.p, oid, len ) == 0 )
{
break;
}
list = list->next;
}
return( list );
}
mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
mbedtls_asn1_named_data **head,
const char *oid, size_t oid_len,
const unsigned char *val,
size_t val_len )
{
mbedtls_asn1_named_data *cur;
if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
{
// Add new entry if not present yet based on OID
//
cur = (mbedtls_asn1_named_data*)mbedtls_calloc( 1,
sizeof(mbedtls_asn1_named_data) );
if( cur == NULL )
return( NULL );
cur->oid.len = oid_len;
cur->oid.p = mbedtls_calloc( 1, oid_len );
if( cur->oid.p == NULL )
{
mbedtls_free( cur );
return( NULL );
}
memcpy( cur->oid.p, oid, oid_len );
cur->val.len = val_len;
if( val_len != 0 )
{
cur->val.p = mbedtls_calloc( 1, val_len );
if( cur->val.p == NULL )
{
mbedtls_free( cur->oid.p );
mbedtls_free( cur );
return( NULL );
}
}
cur->next = *head;
*head = cur;
}
else if( val_len == 0 )
{
mbedtls_free( cur->val.p );
cur->val.p = NULL;
}
else if( cur->val.len != val_len )
{
/*
* Enlarge existing value buffer if needed
* Preserve old data until the allocation succeeded, to leave list in
* a consistent state in case allocation fails.
*/
void *p = mbedtls_calloc( 1, val_len );
if( p == NULL )
return( NULL );
mbedtls_free( cur->val.p );
cur->val.p = p;
cur->val.len = val_len;
}
if( val != NULL && val_len != 0 )
memcpy( cur->val.p, val, val_len );
return( cur );
}
#endif /* MBEDTLS_ASN1_WRITE_C */
Reference in a new issue View git blame Copy permalink