| /* |
| * 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 <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 |
| |
| /* Implementation that should never be optimized out by the compiler */ |
| static void mbedtls_zeroize( void *v, size_t n ) { |
| volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; |
| } |
| |
| /* |
| * 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 > 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_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_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_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 */ |