/* | |
* Generic ASN.1 parsing | |
* | |
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved | |
* 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. | |
* | |
* This file is part of mbed TLS (https://tls.mbed.org) | |
*/ | |
#if !defined(MBEDTLS_CONFIG_FILE) | |
#include "mbedtls/config.h" | |
#else | |
#include MBEDTLS_CONFIG_FILE | |
#endif | |
#if defined(MBEDTLS_ASN1_PARSE_C) | |
#include "mbedtls/asn1.h" | |
#include "mbedtls/platform_util.h" | |
#include <string.h> | |
#if defined(MBEDTLS_BIGNUM_C) | |
#include "mbedtls/bignum.h" | |
#endif | |
#if defined(MBEDTLS_PLATFORM_C) | |
#include "mbedtls/platform.h" | |
#else | |
#include <stdlib.h> | |
#define mbedtls_calloc calloc | |
#define mbedtls_free free | |
#endif | |
/* | |
* ASN.1 DER decoding routines | |
*/ | |
int mbedtls_asn1_get_len( unsigned char **p, | |
const unsigned char *end, | |
size_t *len ) | |
{ | |
if( ( end - *p ) < 1 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
if( ( **p & 0x80 ) == 0 ) | |
*len = *(*p)++; | |
else | |
{ | |
switch( **p & 0x7F ) | |
{ | |
case 1: | |
if( ( end - *p ) < 2 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
*len = (*p)[1]; | |
(*p) += 2; | |
break; | |
case 2: | |
if( ( end - *p ) < 3 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
*len = ( (size_t)(*p)[1] << 8 ) | (*p)[2]; | |
(*p) += 3; | |
break; | |
case 3: | |
if( ( end - *p ) < 4 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
*len = ( (size_t)(*p)[1] << 16 ) | | |
( (size_t)(*p)[2] << 8 ) | (*p)[3]; | |
(*p) += 4; | |
break; | |
case 4: | |
if( ( end - *p ) < 5 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
*len = ( (size_t)(*p)[1] << 24 ) | ( (size_t)(*p)[2] << 16 ) | | |
( (size_t)(*p)[3] << 8 ) | (*p)[4]; | |
(*p) += 5; | |
break; | |
default: | |
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); | |
} | |
} | |
if( *len > (size_t) ( end - *p ) ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
return( 0 ); | |
} | |
int mbedtls_asn1_get_tag( unsigned char **p, | |
const unsigned char *end, | |
size_t *len, int tag ) | |
{ | |
if( ( end - *p ) < 1 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
if( **p != tag ) | |
return( MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ); | |
(*p)++; | |
return( mbedtls_asn1_get_len( p, end, len ) ); | |
} | |
int mbedtls_asn1_get_bool( unsigned char **p, | |
const unsigned char *end, | |
int *val ) | |
{ | |
int ret; | |
size_t len; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_BOOLEAN ) ) != 0 ) | |
return( ret ); | |
if( len != 1 ) | |
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); | |
*val = ( **p != 0 ) ? 1 : 0; | |
(*p)++; | |
return( 0 ); | |
} | |
int mbedtls_asn1_get_int( unsigned char **p, | |
const unsigned char *end, | |
int *val ) | |
{ | |
int ret; | |
size_t len; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 ) | |
return( ret ); | |
if( len == 0 || len > sizeof( int ) || ( **p & 0x80 ) != 0 ) | |
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); | |
*val = 0; | |
while( len-- > 0 ) | |
{ | |
*val = ( *val << 8 ) | **p; | |
(*p)++; | |
} | |
return( 0 ); | |
} | |
#if defined(MBEDTLS_BIGNUM_C) | |
int mbedtls_asn1_get_mpi( unsigned char **p, | |
const unsigned char *end, | |
mbedtls_mpi *X ) | |
{ | |
int ret; | |
size_t len; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 ) | |
return( ret ); | |
ret = mbedtls_mpi_read_binary( X, *p, len ); | |
*p += len; | |
return( ret ); | |
} | |
#endif /* MBEDTLS_BIGNUM_C */ | |
int mbedtls_asn1_get_bitstring( unsigned char **p, const unsigned char *end, | |
mbedtls_asn1_bitstring *bs) | |
{ | |
int ret; | |
/* Certificate type is a single byte bitstring */ | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING ) ) != 0 ) | |
return( ret ); | |
/* Check length, subtract one for actual bit string length */ | |
if( bs->len < 1 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
bs->len -= 1; | |
/* Get number of unused bits, ensure unused bits <= 7 */ | |
bs->unused_bits = **p; | |
if( bs->unused_bits > 7 ) | |
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); | |
(*p)++; | |
/* Get actual bitstring */ | |
bs->p = *p; | |
*p += bs->len; | |
if( *p != end ) | |
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); | |
return( 0 ); | |
} | |
/* | |
* Get a bit string without unused bits | |
*/ | |
int mbedtls_asn1_get_bitstring_null( unsigned char **p, const unsigned char *end, | |
size_t *len ) | |
{ | |
int ret; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, len, MBEDTLS_ASN1_BIT_STRING ) ) != 0 ) | |
return( ret ); | |
if( (*len)-- < 2 || *(*p)++ != 0 ) | |
return( MBEDTLS_ERR_ASN1_INVALID_DATA ); | |
return( 0 ); | |
} | |
/* | |
* Parses and splits an ASN.1 "SEQUENCE OF <tag>" | |
*/ | |
int mbedtls_asn1_get_sequence_of( unsigned char **p, | |
const unsigned char *end, | |
mbedtls_asn1_sequence *cur, | |
int tag) | |
{ | |
int ret; | |
size_t len; | |
mbedtls_asn1_buf *buf; | |
/* Get main sequence tag */ | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, | |
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) | |
return( ret ); | |
if( *p + len != end ) | |
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); | |
while( *p < end ) | |
{ | |
buf = &(cur->buf); | |
buf->tag = **p; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &buf->len, tag ) ) != 0 ) | |
return( ret ); | |
buf->p = *p; | |
*p += buf->len; | |
/* Allocate and assign next pointer */ | |
if( *p < end ) | |
{ | |
cur->next = (mbedtls_asn1_sequence*)mbedtls_calloc( 1, | |
sizeof( mbedtls_asn1_sequence ) ); | |
if( cur->next == NULL ) | |
return( MBEDTLS_ERR_ASN1_ALLOC_FAILED ); | |
cur = cur->next; | |
} | |
} | |
/* Set final sequence entry's next pointer to NULL */ | |
cur->next = NULL; | |
if( *p != end ) | |
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); | |
return( 0 ); | |
} | |
int mbedtls_asn1_get_alg( unsigned char **p, | |
const unsigned char *end, | |
mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params ) | |
{ | |
int ret; | |
size_t len; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, | |
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) | |
return( ret ); | |
if( ( end - *p ) < 1 ) | |
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); | |
alg->tag = **p; | |
end = *p + len; | |
if( ( ret = mbedtls_asn1_get_tag( p, end, &alg->len, MBEDTLS_ASN1_OID ) ) != 0 ) | |
return( ret ); | |
alg->p = *p; | |
*p += alg->len; | |
if( *p == end ) | |
{ | |
mbedtls_platform_zeroize( params, sizeof(mbedtls_asn1_buf) ); | |
return( 0 ); | |
} | |
params->tag = **p; | |
(*p)++; | |
if( ( ret = mbedtls_asn1_get_len( p, end, ¶ms->len ) ) != 0 ) | |
return( ret ); | |
params->p = *p; | |
*p += params->len; | |
if( *p != end ) | |
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); | |
return( 0 ); | |
} | |
int mbedtls_asn1_get_alg_null( unsigned char **p, | |
const unsigned char *end, | |
mbedtls_asn1_buf *alg ) | |
{ | |
int ret; | |
mbedtls_asn1_buf params; | |
memset( ¶ms, 0, sizeof(mbedtls_asn1_buf) ); | |
if( ( ret = mbedtls_asn1_get_alg( p, end, alg, ¶ms ) ) != 0 ) | |
return( ret ); | |
if( ( params.tag != MBEDTLS_ASN1_NULL && params.tag != 0 ) || params.len != 0 ) | |
return( MBEDTLS_ERR_ASN1_INVALID_DATA ); | |
return( 0 ); | |
} | |
void mbedtls_asn1_free_named_data( mbedtls_asn1_named_data *cur ) | |
{ | |
if( cur == NULL ) | |
return; | |
mbedtls_free( cur->oid.p ); | |
mbedtls_free( cur->val.p ); | |
mbedtls_platform_zeroize( cur, sizeof( mbedtls_asn1_named_data ) ); | |
} | |
void mbedtls_asn1_free_named_data_list( mbedtls_asn1_named_data **head ) | |
{ | |
mbedtls_asn1_named_data *cur; | |
while( ( cur = *head ) != NULL ) | |
{ | |
*head = cur->next; | |
mbedtls_asn1_free_named_data( cur ); | |
mbedtls_free( cur ); | |
} | |
} | |
mbedtls_asn1_named_data *mbedtls_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 ); | |
} | |
#endif /* MBEDTLS_ASN1_PARSE_C */ |