mbedtls/tests/suites/test_suite_asn1parse.function
Gilles Peskine 27d806fab4 Add ASN.1 parsing tests
Add self-contained ASN.1 parsing tests, so that ASN.1 parsing is not
solely tested through X.509 and TLS.

The tests cover every function and almost complete line coverage in
asn1parse.c.

A few test cases containing negative and edge case INTEGER values are
deliberately deactivated because the historical library behavior is at
odds with official specifications, but changing the behavior might
break interoperability.

Other than that, these tests revealed a couple of minor bugs which
will be fixed in subsequent commits.
2019-09-11 15:46:44 +02:00

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/* BEGIN_HEADER */
#include <errno.h>
#include <stdlib.h>
#include <limits.h>
#include "mbedtls/bignum.h"
#include "mbedtls/asn1.h"
#if defined(MBEDTLS_ASN1_WRITE_C)
#include "mbedtls/asn1write.h"
#endif
#define ERR_PARSE_INCONSISTENCY INT_MAX
static int nested_parse( unsigned char **const p,
const unsigned char *const end )
{
int ret;
size_t len = 0;
size_t len2 = 0;
unsigned char *const start = *p;
unsigned char *content_start;
unsigned char tag;
/* First get the length, skipping over the tag. */
content_start = start + 1;
ret = mbedtls_asn1_get_len( &content_start, end, &len );
TEST_ASSERT( content_start <= end );
if( ret != 0 )
return( ret );
/* Since we have a valid element start (tag and length), retrieve and
* check the tag. */
tag = start[0];
TEST_EQUAL( mbedtls_asn1_get_tag( p, end, &len2, tag ^ 1 ),
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
*p = start;
TEST_EQUAL( mbedtls_asn1_get_tag( p, end, &len2, tag ), 0 );
TEST_EQUAL( len, len2 );
TEST_ASSERT( *p == content_start );
*p = content_start;
switch( tag & 0x1f )
{
case MBEDTLS_ASN1_BOOLEAN:
{
int val = -257;
*p = start;
ret = mbedtls_asn1_get_bool( p, end, &val );
if( ret == 0 )
TEST_ASSERT( val == 0 || val == 1 );
break;
}
case MBEDTLS_ASN1_INTEGER:
{
#if defined(MBEDTLS_BIGNUM_C)
mbedtls_mpi mpi;
mbedtls_mpi_init( &mpi );
*p = start;
ret = mbedtls_asn1_get_mpi( p, end, &mpi );
mbedtls_mpi_free( &mpi );
#endif
/* If we're sure that the number fits in an int, also
* call mbedtls_asn1_get_int(). */
if( ret == 0 && len < sizeof( int ) )
{
int val = -257;
unsigned char *q = start;
ret = mbedtls_asn1_get_int( &q, end, &val );
TEST_ASSERT( *p == q );
}
break;
}
case MBEDTLS_ASN1_BIT_STRING:
{
mbedtls_asn1_bitstring bs;
*p = start;
ret = mbedtls_asn1_get_bitstring( p, end, &bs );
break;
}
case MBEDTLS_ASN1_SEQUENCE:
{
while( *p <= end && *p < content_start + len && ret == 0 )
ret = nested_parse( p, content_start + len );
break;
}
case MBEDTLS_ASN1_OCTET_STRING:
case MBEDTLS_ASN1_NULL:
case MBEDTLS_ASN1_OID:
case MBEDTLS_ASN1_UTF8_STRING:
case MBEDTLS_ASN1_SET:
case MBEDTLS_ASN1_PRINTABLE_STRING:
case MBEDTLS_ASN1_T61_STRING:
case MBEDTLS_ASN1_IA5_STRING:
case MBEDTLS_ASN1_UTC_TIME:
case MBEDTLS_ASN1_GENERALIZED_TIME:
case MBEDTLS_ASN1_UNIVERSAL_STRING:
case MBEDTLS_ASN1_BMP_STRING:
default:
/* No further testing implemented for this tag. */
*p += len;
return( 0 );
}
TEST_ASSERT( *p <= end );
return( ret );
exit:
return( ERR_PARSE_INCONSISTENCY );
}
int get_len_step( const data_t *input, size_t buffer_size,
size_t actual_length )
{
unsigned char *buf = NULL;
unsigned char *p = NULL;
size_t parsed_length;
int ret;
test_set_step( buffer_size );
/* Allocate a new buffer of exactly the length to parse each time.
* This gives memory sanitizers a chance to catch buffer overreads. */
if( buffer_size == 0 )
{
ASSERT_ALLOC( buf, 1 );
p = buf + 1;
}
else
{
ASSERT_ALLOC( buf, buffer_size );
if( buffer_size > input->len )
{
memcpy( buf, input->x, input->len );
memset( buf + input->len, 'A', buffer_size - input->len );
}
else
{
memcpy( buf, input->x, buffer_size );
}
p = buf;
}
ret = mbedtls_asn1_get_len( &p, buf + buffer_size, &parsed_length );
if( buffer_size >= input->len + actual_length )
{
TEST_EQUAL( ret, 0 );
TEST_ASSERT( p == buf + input->len );
TEST_EQUAL( parsed_length, actual_length );
}
else
{
TEST_EQUAL( ret, MBEDTLS_ERR_ASN1_OUT_OF_DATA );
}
mbedtls_free( buf );
return( 1 );
exit:
/* It may be impossible to allocate large lengths on embedded platforms.
* Pass in this case (though it would be better to mark the test
* as skipped). */
if( buf == NULL )
return( 1 );
mbedtls_free( buf );
return( 0 );
}
/* END_HEADER */
/* BEGIN_DEPENDENCIES
* depends_on:MBEDTLS_ASN1_PARSE_C
* END_DEPENDENCIES
*/
/* BEGIN_CASE */
void parse_prefixes( const data_t *input,
int actual_length_arg,
int last_result )
{
size_t actual_length = actual_length_arg;
unsigned char *buf = NULL;
unsigned char *p = NULL;
size_t buffer_size;
int ret;
for( buffer_size = 1; buffer_size <= input->len; buffer_size++ )
{
test_set_step( buffer_size );
/* Allocate a new buffer of exactly the length to parse each time.
* This gives memory sanitizers a chance to catch buffer overreads. */
ASSERT_ALLOC( buf, buffer_size );
memcpy( buf, input->x, buffer_size );
p = buf;
ret = nested_parse( &p, buf + buffer_size );
if( ret == ERR_PARSE_INCONSISTENCY )
goto exit;
if( actual_length > 0 && buffer_size >= actual_length )
{
TEST_EQUAL( ret, last_result );
if( ret == 0 )
TEST_ASSERT( p == buf + actual_length );
}
else
{
TEST_EQUAL( ret, MBEDTLS_ERR_ASN1_OUT_OF_DATA );
}
mbedtls_free( buf );
buf = NULL;
}
exit:
mbedtls_free( buf );
}
/* END_CASE */
/* BEGIN_CASE */
void get_len( const data_t *input, int actual_length_arg )
{
size_t actual_length = actual_length_arg;
size_t buffer_size;
for( buffer_size = 1; buffer_size <= input->len + 1; buffer_size++ )
{
if( ! get_len_step( input, buffer_size, actual_length ) )
goto exit;
}
if( ! get_len_step( input, input->len + actual_length - 1, actual_length ) )
goto exit;
if( ! get_len_step( input, input->len + actual_length, actual_length ) )
goto exit;
}
/* END_CASE */
/* BEGIN_CASE */
void get_boolean( const data_t *input,
int expected_value, int expected_result )
{
unsigned char *p = input->x;
int val;
int ret;
ret = mbedtls_asn1_get_bool( &p, input->x + input->len, &val );
TEST_EQUAL( ret, expected_result );
if( expected_result == 0 )
{
TEST_EQUAL( val, expected_value );
TEST_ASSERT( p == input->x + input->len );
}
}
/* END_CASE */
/* BEGIN_CASE */
void get_integer( const data_t *input,
const char *expected_hex, int expected_result )
{
unsigned char *p;
#if defined(MBEDTLS_BIGNUM_C)
mbedtls_mpi expected_mpi;
mbedtls_mpi actual_mpi;
#endif
long expected_value;
int expected_result_for_int = expected_result;
int expected_result_for_mpi = expected_result;
int val;
int ret;
#if defined(MBEDTLS_BIGNUM_C)
mbedtls_mpi_init( &expected_mpi );
mbedtls_mpi_init( &actual_mpi );
#endif
errno = 0;
expected_value = strtol( expected_hex, NULL, 16 );
if( expected_result == 0 &&
( errno == ERANGE
#if LONG_MAX > INT_MAX
|| expected_value > INT_MAX || expected_value < INT_MIN
#endif
) )
{
expected_result_for_int = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
}
p = input->x;
ret = mbedtls_asn1_get_int( &p, input->x + input->len, &val );
TEST_EQUAL( ret, expected_result_for_int );
if( ret == 0 )
{
TEST_EQUAL( val, expected_value );
TEST_ASSERT( p == input->x + input->len );
}
#if defined(MBEDTLS_BIGNUM_C)
ret = mbedtls_mpi_read_string( &expected_mpi, 16, expected_hex );
TEST_ASSERT( ret == 0 || ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
if( ret == MBEDTLS_ERR_MPI_BAD_INPUT_DATA )
{
/* The data overflows the maximum MPI size. */
expected_result_for_mpi = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
}
p = input->x;
ret = mbedtls_asn1_get_mpi( &p, input->x + input->len, &actual_mpi );
TEST_EQUAL( ret, expected_result_for_mpi );
if( ret == 0 )
{
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &actual_mpi , &expected_mpi ) == 0 );
TEST_ASSERT( p == input->x + input->len );
}
#endif
exit:
#if defined(MBEDTLS_BIGNUM_C)
mbedtls_mpi_free( &expected_mpi );
mbedtls_mpi_free( &actual_mpi );
#endif
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_BIGNUM_C */
void get_mpi_too_large( )
{
unsigned char *buf = NULL;
unsigned char *p;
mbedtls_mpi actual_mpi;
size_t too_many_octets =
MBEDTLS_MPI_MAX_LIMBS * sizeof(mbedtls_mpi_uint) + 1;
size_t size = too_many_octets + 6;
mbedtls_mpi_init( &actual_mpi );
ASSERT_ALLOC( buf, size );
buf[0] = 0x02; /* tag: INTEGER */
buf[1] = 0x84; /* 4-octet length */
buf[2] = ( too_many_octets >> 24 ) & 0xff;
buf[3] = ( too_many_octets >> 16 ) & 0xff;
buf[4] = ( too_many_octets >> 8 ) & 0xff;
buf[5] = too_many_octets & 0xff;
buf[6] = 0x01; /* most significant octet */
p = buf;
TEST_EQUAL( mbedtls_asn1_get_mpi( &p, buf + size, &actual_mpi ),
MBEDTLS_ERR_MPI_ALLOC_FAILED );
exit:
mbedtls_mpi_free( &actual_mpi );
mbedtls_free( buf );
}
/* END_CASE */
/* BEGIN_CASE */
void get_bitstring( const data_t *input,
int expected_length, int expected_unused_bits,
int expected_result, int expected_result_null )
{
mbedtls_asn1_bitstring bs = { 0xdead, 0x21, NULL };
unsigned char *p = input->x;
TEST_EQUAL( mbedtls_asn1_get_bitstring( &p, input->x + input->len, &bs ),
expected_result );
if( expected_result == 0 )
{
TEST_EQUAL( bs.len, (size_t) expected_length );
TEST_EQUAL( bs.unused_bits, expected_unused_bits );
TEST_ASSERT( bs.p != NULL );
TEST_EQUAL( bs.p - input->x + bs.len, input->len );
TEST_ASSERT( p == input->x + input->len );
}
p = input->x;
TEST_EQUAL( mbedtls_asn1_get_bitstring_null( &p, input->x + input->len,
&bs.len ),
expected_result_null );
if( expected_result_null == 0 )
{
TEST_EQUAL( bs.len, (size_t) expected_length );
if( expected_result == 0 )
TEST_ASSERT( p == input->x + input->len - bs.len );
}
}
/* END_CASE */
/* BEGIN_CASE */
void get_sequence_of( const data_t *input, int tag,
const char *description,
int expected_result )
{
mbedtls_asn1_sequence head = { { 0, 0, NULL }, NULL };
mbedtls_asn1_sequence *cur, *next;
unsigned char *p = input->x;
const char *rest = description;
unsigned long n;
TEST_EQUAL( mbedtls_asn1_get_sequence_of( &p, input->x + input->len,
&head, tag ),
expected_result );
if( expected_result == 0 )
{
TEST_ASSERT( p == input->x + input->len );
if( ! *rest )
{
TEST_EQUAL( head.buf.tag, 0 );
TEST_ASSERT( head.buf.p == NULL );
TEST_EQUAL( head.buf.len, 0 );
TEST_ASSERT( head.next == NULL );
}
else
{
cur = &head;
while( *rest )
{
++test_info.step;
TEST_ASSERT( cur != NULL );
TEST_EQUAL( cur->buf.tag, tag );
n = strtoul( rest, (char **) &rest, 0 );
TEST_EQUAL( n, (size_t)( cur->buf.p - input->x ) );
++rest;
n = strtoul( rest, (char **) &rest, 0 );
TEST_EQUAL( n, cur->buf.len );
if( *rest )
++rest;
cur = cur->next;
}
TEST_ASSERT( cur == NULL );
}
}
exit:
cur = head.next;
while( cur != NULL )
{
next = cur->next;
mbedtls_free( cur );
cur = next;
}
}
/* END_CASE */
/* BEGIN_CASE */
void get_alg( const data_t *input,
int oid_offset, int oid_length,
int params_tag, int params_offset, int params_length,
int total_length,
int expected_result )
{
mbedtls_asn1_buf oid = { -1, 0, NULL };
mbedtls_asn1_buf params = { -1, 0, NULL };
unsigned char *p = input->x;
int ret;
TEST_EQUAL( mbedtls_asn1_get_alg( &p, input->x + input->len,
&oid, &params ),
expected_result );
if( expected_result == 0 )
{
TEST_EQUAL( oid.tag, MBEDTLS_ASN1_OID );
TEST_EQUAL( oid.p - input->x, oid_offset );
TEST_EQUAL( oid.len, (size_t) oid_length );
TEST_EQUAL( params.tag, params_tag );
if( params_offset != 0 )
TEST_EQUAL( params.p - input->x, params_offset );
else
TEST_ASSERT( params.p == NULL );
TEST_EQUAL( params.len, (size_t) params_length );
TEST_EQUAL( p - input->x, total_length );
}
ret = mbedtls_asn1_get_alg_null( &p, input->x + input->len, &oid );
if( expected_result == 0 && params_offset == 0 )
{
TEST_EQUAL( oid.tag, MBEDTLS_ASN1_OID );
TEST_EQUAL( oid.p - input->x, oid_offset );
TEST_EQUAL( oid.len, (size_t) oid_length );
TEST_EQUAL( p - input->x, total_length );
}
else
TEST_ASSERT( ret != 0 );
}
/* END_CASE */
/* BEGIN_CASE */
void find_named_data( data_t *oid0, data_t *oid1, data_t *oid2, data_t *oid3,
data_t *needle, int from, int position )
{
mbedtls_asn1_named_data nd[] ={
{ {0x06, oid0->len, oid0->x}, {0, 0, NULL}, NULL, 0 },
{ {0x06, oid1->len, oid1->x}, {0, 0, NULL}, NULL, 0 },
{ {0x06, oid2->len, oid2->x}, {0, 0, NULL}, NULL, 0 },
{ {0x06, oid3->len, oid3->x}, {0, 0, NULL}, NULL, 0 },
};
mbedtls_asn1_named_data *pointers[ARRAY_LENGTH( nd ) + 1];
size_t i;
mbedtls_asn1_named_data *found;
for( i = 0; i < ARRAY_LENGTH( nd ); i++ )
pointers[i] = &nd[i];
pointers[ARRAY_LENGTH( nd )] = NULL;
for( i = 0; i < ARRAY_LENGTH( nd ); i++ )
nd[i].next = pointers[i+1];
found = mbedtls_asn1_find_named_data( pointers[from],
(const char *) needle->x,
needle->len );
TEST_ASSERT( found == pointers[position] );
}
/* END_CASE */
/* BEGIN_CASE */
void free_named_data_null( )
{
mbedtls_asn1_free_named_data( NULL );
goto exit; /* Silence unused label warning */
}
/* END_CASE */
/* BEGIN_CASE */
void free_named_data( int with_oid, int with_val, int with_next )
{
mbedtls_asn1_named_data next =
{ {0x06, 0, NULL}, {0, 0xcafe, NULL}, NULL, 0 };
mbedtls_asn1_named_data head =
{ {0x06, 0, NULL}, {0, 0, NULL}, NULL, 0 };
if( with_oid )
ASSERT_ALLOC( head.oid.p, 1 );
if( with_val )
ASSERT_ALLOC( head.val.p, 1 );
if( with_next )
head.next = &next;
mbedtls_asn1_free_named_data( &head );
TEST_ASSERT( head.oid.p == NULL );
TEST_ASSERT( head.val.p == NULL );
TEST_ASSERT( head.next == NULL );
TEST_ASSERT( next.val.len == 0xcafe );
exit:
mbedtls_free( head.oid.p );
mbedtls_free( head.val.p );
}
/* END_CASE */
/* BEGIN_CASE */
void free_named_data_list( int length )
{
mbedtls_asn1_named_data *head = NULL;
int i;
for( i = 0; i < length; i++ )
{
mbedtls_asn1_named_data *new = NULL;
ASSERT_ALLOC( new, sizeof( mbedtls_asn1_named_data ) );
head->next = new;
head = new;
}
mbedtls_asn1_free_named_data_list( &head );
TEST_ASSERT( head == NULL );
/* Most of the point of the test is that it doesn't leak memory.
* So this test is only really useful under a memory leak detection
* framework. */
exit:
mbedtls_asn1_free_named_data_list( &head );
}
/* END_CASE */