lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-10-24 13:32:59 +03:00
Code Activity

Move asn1_skip_integer to the asn1_helpers module

Browse Source 
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine
2021-02-13 00:25:53 +01:00
parent 57948369c4
commit 8e94efe4ba
3 changed files with 86 additions and 56 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
tests/src/asn1_helpers.c
View File

@@ -23,3 +23,52 @@
#include <test/helpers.h>
#include <test/macros.h>
#if defined(MBEDTLS_ASN1_PARSE_C)
#include <mbedtls/asn1.h>
int mbedtls_test_asn1_skip_integer( unsigned char **p, const unsigned char *end,
size_t min_bits, size_t max_bits,
int must_be_odd )
{
size_t len;
size_t actual_bits;
unsigned char msb;
TEST_EQUAL( mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_INTEGER ),
0 );
/* Check if the retrieved length doesn't extend the actual buffer's size.
* It is assumed here, that end >= p, which validates casting to size_t. */
TEST_ASSERT( len <= (size_t)( end - *p) );
/* Tolerate a slight departure from DER encoding:
* - 0 may be represented by an empty string or a 1-byte string.
* - The sign bit may be used as a value bit. */
if( ( len == 1 && ( *p )[0] == 0 ) ||
( len > 1 && ( *p )[0] == 0 && ( ( *p )[1] & 0x80 ) != 0 ) )
{
++( *p );
--len;
}
if( min_bits == 0 && len == 0 )
return( 1 );
msb = ( *p )[0];
TEST_ASSERT( msb != 0 );
actual_bits = 8 * ( len - 1 );
while( msb != 0 )
{
msb >>= 1;
++actual_bits;
}
TEST_ASSERT( actual_bits >= min_bits );
TEST_ASSERT( actual_bits <= max_bits );
if( must_be_odd )
TEST_ASSERT( ( ( *p )[len-1] & 1 ) != 0 );
*p += len;
return( 1 );
exit:
return( 0 );
}
#endif /* MBEDTLS_ASN1_PARSE_C */