diff options
Diffstat (limited to 'compat/verification/asn1parse.c')
| -rw-r--r-- | compat/verification/asn1parse.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/compat/verification/asn1parse.c b/compat/verification/asn1parse.c new file mode 100644 index 0000000..e81713c --- /dev/null +++ b/compat/verification/asn1parse.c @@ -0,0 +1,393 @@ +/* + * Generic ASN.1 parsing + * + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * SPDX-License-Identifier: GPL-2.0 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * 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" + +#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 == 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_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 */ |