mbed TLS Build
Diff: library/asn1write.c
- Revision:
- 0:cdf462088d13
diff -r 000000000000 -r cdf462088d13 library/asn1write.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/library/asn1write.c Thu Jan 05 00:18:44 2017 +0000 @@ -0,0 +1,390 @@ +/* + * ASN.1 buffer writing functionality + * + * 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_WRITE_C) + +#include "mbedtls/asn1write.h" + +#include <string.h> + +#if defined(MBEDTLS_PLATFORM_C) +#include "mbedtls/platform.h" +#else +#include <stdlib.h> +#define mbedtls_calloc calloc +#define mbedtls_free free +#endif + +int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start, size_t len ) +{ + if( len < 0x80 ) + { + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = (unsigned char) len; + return( 1 ); + } + + if( len <= 0xFF ) + { + if( *p - start < 2 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = (unsigned char) len; + *--(*p) = 0x81; + return( 2 ); + } + + if( len <= 0xFFFF ) + { + if( *p - start < 3 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = ( len ) & 0xFF; + *--(*p) = ( len >> 8 ) & 0xFF; + *--(*p) = 0x82; + return( 3 ); + } + + if( len <= 0xFFFFFF ) + { + if( *p - start < 4 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = ( len ) & 0xFF; + *--(*p) = ( len >> 8 ) & 0xFF; + *--(*p) = ( len >> 16 ) & 0xFF; + *--(*p) = 0x83; + return( 4 ); + } + + if( len <= 0xFFFFFFFF ) + { + if( *p - start < 5 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = ( len ) & 0xFF; + *--(*p) = ( len >> 8 ) & 0xFF; + *--(*p) = ( len >> 16 ) & 0xFF; + *--(*p) = ( len >> 24 ) & 0xFF; + *--(*p) = 0x84; + return( 5 ); + } + + return( MBEDTLS_ERR_ASN1_INVALID_LENGTH ); +} + +int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag ) +{ + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = tag; + + return( 1 ); +} + +int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start, + const unsigned char *buf, size_t size ) +{ + size_t len = 0; + + if( *p < start || (size_t)( *p - start ) < size ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + len = size; + (*p) -= len; + memcpy( *p, buf, len ); + + return( (int) len ); +} + +#if defined(MBEDTLS_BIGNUM_C) +int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, const mbedtls_mpi *X ) +{ + int ret; + size_t len = 0; + + // Write the MPI + // + len = mbedtls_mpi_size( X ); + + if( *p < start || (size_t)( *p - start ) < len ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + (*p) -= len; + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) ); + + // DER format assumes 2s complement for numbers, so the leftmost bit + // should be 0 for positive numbers and 1 for negative numbers. + // + if( X->s ==1 && **p & 0x80 ) + { + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = 0x00; + len += 1; + } + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) ); + + ret = (int) len; + +cleanup: + return( ret ); +} +#endif /* MBEDTLS_BIGNUM_C */ + +int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start ) +{ + int ret; + size_t len = 0; + + // Write NULL + // + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start, + const char *oid, size_t oid_len ) +{ + int ret; + size_t len = 0; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, + (const unsigned char *) oid, oid_len ) ); + MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start, + const char *oid, size_t oid_len, + size_t par_len ) +{ + int ret; + size_t len = 0; + + if( par_len == 0 ) + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) ); + else + len += par_len; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolean ) +{ + int ret; + size_t len = 0; + + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = (boolean) ? 255 : 0; + len++; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BOOLEAN ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val ) +{ + int ret; + size_t len = 0; + + // TODO negative values and values larger than 128 + // DER format assumes 2s complement for numbers, so the leftmost bit + // should be 0 for positive numbers and 1 for negative numbers. + // + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + len += 1; + *--(*p) = val; + + if( val > 0 && **p & 0x80 ) + { + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = 0x00; + len += 1; + } + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_printable_string( unsigned char **p, unsigned char *start, + const char *text, size_t text_len ) +{ + int ret; + size_t len = 0; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, + (const unsigned char *) text, text_len ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_PRINTABLE_STRING ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start, + const char *text, size_t text_len ) +{ + int ret; + size_t len = 0; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, + (const unsigned char *) text, text_len ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_IA5_STRING ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start, + const unsigned char *buf, size_t bits ) +{ + int ret; + size_t len = 0, size; + + size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 ); + + // Calculate byte length + // + if( *p < start || (size_t)( *p - start ) < size + 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + len = size + 1; + (*p) -= size; + memcpy( *p, buf, size ); + + // Write unused bits + // + *--(*p) = (unsigned char) (size * 8 - bits); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) ); + + return( (int) len ); +} + +int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start, + const unsigned char *buf, size_t size ) +{ + int ret; + size_t len = 0; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, size ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) ); + + return( (int) len ); +} + +mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data **head, + const char *oid, size_t oid_len, + const unsigned char *val, + size_t val_len ) +{ + mbedtls_asn1_named_data *cur; + + if( ( cur = mbedtls_asn1_find_named_data( *head, oid, oid_len ) ) == NULL ) + { + // Add new entry if not present yet based on OID + // + cur = (mbedtls_asn1_named_data*)mbedtls_calloc( 1, + sizeof(mbedtls_asn1_named_data) ); + if( cur == NULL ) + return( NULL ); + + cur->oid.len = oid_len; + cur->oid.p = mbedtls_calloc( 1, oid_len ); + if( cur->oid.p == NULL ) + { + mbedtls_free( cur ); + return( NULL ); + } + + memcpy( cur->oid.p, oid, oid_len ); + + cur->val.len = val_len; + cur->val.p = mbedtls_calloc( 1, val_len ); + if( cur->val.p == NULL ) + { + mbedtls_free( cur->oid.p ); + mbedtls_free( cur ); + return( NULL ); + } + + cur->next = *head; + *head = cur; + } + else if( cur->val.len < val_len ) + { + /* + * Enlarge existing value buffer if needed + * Preserve old data until the allocation succeeded, to leave list in + * a consistent state in case allocation fails. + */ + void *p = mbedtls_calloc( 1, val_len ); + if( p == NULL ) + return( NULL ); + + mbedtls_free( cur->val.p ); + cur->val.p = p; + cur->val.len = val_len; + } + + if( val != NULL ) + memcpy( cur->val.p, val, val_len ); + + return( cur ); +} +#endif /* MBEDTLS_ASN1_WRITE_C */