| /* |
| * ASN.1 buffer writing functionality |
| * |
| * Copyright (C) 2006-2014, Brainspark B.V. |
| * |
| * This file is part of PolarSSL (http://www.polarssl.org) |
| * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> |
| * |
| * All rights reserved. |
| * |
| * 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. |
| */ |
| |
| #if !defined(POLARSSL_CONFIG_FILE) |
| #include "polarssl/config.h" |
| #else |
| #include POLARSSL_CONFIG_FILE |
| #endif |
| |
| #if defined(POLARSSL_ASN1_WRITE_C) |
| |
| #include "polarssl/asn1write.h" |
| |
| #if defined(POLARSSL_PLATFORM_C) |
| #include "polarssl/platform.h" |
| #else |
| #include <stdlib.h> |
| #define polarssl_malloc malloc |
| #define polarssl_free free |
| #endif |
| |
| int asn1_write_len( unsigned char **p, unsigned char *start, size_t len ) |
| { |
| if( len < 0x80 ) |
| { |
| if( *p - start < 1 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = (unsigned char) len; |
| return( 1 ); |
| } |
| |
| if( len <= 0xFF ) |
| { |
| if( *p - start < 2 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = (unsigned char) len; |
| *--(*p) = 0x81; |
| return( 2 ); |
| } |
| |
| if( *p - start < 3 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| // We assume we never have lengths larger than 65535 bytes |
| // |
| *--(*p) = len % 256; |
| *--(*p) = ( len / 256 ) % 256; |
| *--(*p) = 0x82; |
| |
| return( 3 ); |
| } |
| |
| int asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag ) |
| { |
| if( *p - start < 1 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = tag; |
| |
| return( 1 ); |
| } |
| |
| int asn1_write_raw_buffer( unsigned char **p, unsigned char *start, |
| const unsigned char *buf, size_t size ) |
| { |
| size_t len = 0; |
| |
| if( *p - start < (int) size ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| len = size; |
| (*p) -= len; |
| memcpy( *p, buf, len ); |
| |
| return( (int) len ); |
| } |
| |
| #if defined(POLARSSL_BIGNUM_C) |
| int asn1_write_mpi( unsigned char **p, unsigned char *start, mpi *X ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| // Write the MPI |
| // |
| len = mpi_size( X ); |
| |
| if( *p - start < (int) len ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| (*p) -= len; |
| MPI_CHK( 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( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = 0x00; |
| len += 1; |
| } |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) ); |
| |
| ret = (int) len; |
| |
| cleanup: |
| return( ret ); |
| } |
| #endif /* POLARSSL_BIGNUM_C */ |
| |
| int asn1_write_null( unsigned char **p, unsigned char *start ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| // Write NULL |
| // |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, 0) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_NULL ) ); |
| |
| return( (int) len ); |
| } |
| |
| int asn1_write_oid( unsigned char **p, unsigned char *start, |
| const char *oid, size_t oid_len ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, |
| (const unsigned char *) oid, oid_len ) ); |
| ASN1_CHK_ADD( len , asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len , asn1_write_tag( p, start, ASN1_OID ) ); |
| |
| return( (int) len ); |
| } |
| |
| int 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 ) |
| ASN1_CHK_ADD( len, asn1_write_null( p, start ) ); |
| else |
| len += par_len; |
| |
| ASN1_CHK_ADD( len, asn1_write_oid( p, start, oid, oid_len ) ); |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, |
| ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ); |
| |
| return( (int) len ); |
| } |
| |
| int asn1_write_bool( unsigned char **p, unsigned char *start, int boolean ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| if( *p - start < 1 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = (boolean) ? 1 : 0; |
| len++; |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BOOLEAN ) ); |
| |
| return( (int) len ); |
| } |
| |
| int 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( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| len += 1; |
| *--(*p) = val; |
| |
| if ( val > 0 && **p & 0x80 ) |
| { |
| if( *p - start < 1 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| *--(*p) = 0x00; |
| len += 1; |
| } |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) ); |
| |
| return( (int) len ); |
| } |
| |
| int asn1_write_printable_string( unsigned char **p, unsigned char *start, |
| const char *text, size_t text_len ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, |
| (const unsigned char *) text, text_len ) ); |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_PRINTABLE_STRING ) ); |
| |
| return( (int) len ); |
| } |
| |
| int asn1_write_ia5_string( unsigned char **p, unsigned char *start, |
| const char *text, size_t text_len ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, |
| (const unsigned char *) text, text_len ) ); |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_IA5_STRING ) ); |
| |
| return( (int) len ); |
| } |
| |
| int 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 < (int) size + 1 ) |
| return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| len = size + 1; |
| (*p) -= size; |
| memcpy( *p, buf, size ); |
| |
| // Write unused bits |
| // |
| *--(*p) = (unsigned char) (size * 8 - bits); |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) ); |
| |
| return( (int) len ); |
| } |
| |
| int asn1_write_octet_string( unsigned char **p, unsigned char *start, |
| const unsigned char *buf, size_t size ) |
| { |
| int ret; |
| size_t len = 0; |
| |
| ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, buf, size ) ); |
| |
| ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) ); |
| ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OCTET_STRING ) ); |
| |
| return( (int) len ); |
| } |
| |
| asn1_named_data *asn1_store_named_data( asn1_named_data **head, |
| const char *oid, size_t oid_len, |
| const unsigned char *val, |
| size_t val_len ) |
| { |
| asn1_named_data *cur; |
| |
| if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL ) |
| { |
| // Add new entry if not present yet based on OID |
| // |
| if( ( cur = polarssl_malloc( sizeof(asn1_named_data) ) ) == NULL ) |
| return( NULL ); |
| |
| memset( cur, 0, sizeof(asn1_named_data) ); |
| |
| cur->oid.len = oid_len; |
| cur->oid.p = polarssl_malloc( oid_len ); |
| if( cur->oid.p == NULL ) |
| { |
| polarssl_free( cur ); |
| return( NULL ); |
| } |
| |
| cur->val.len = val_len; |
| cur->val.p = polarssl_malloc( val_len ); |
| if( cur->val.p == NULL ) |
| { |
| polarssl_free( cur->oid.p ); |
| polarssl_free( cur ); |
| return( NULL ); |
| } |
| |
| memcpy( cur->oid.p, oid, oid_len ); |
| |
| cur->next = *head; |
| *head = cur; |
| } |
| else if( cur->val.len < val_len ) |
| { |
| // Enlarge existing value buffer if needed |
| // |
| polarssl_free( cur->val.p ); |
| cur->val.p = NULL; |
| |
| cur->val.len = val_len; |
| cur->val.p = polarssl_malloc( val_len ); |
| if( cur->val.p == NULL ) |
| { |
| polarssl_free( cur->oid.p ); |
| polarssl_free( cur ); |
| return( NULL ); |
| } |
| } |
| |
| if( val != NULL ) |
| memcpy( cur->val.p, val, val_len ); |
| |
| return( cur ); |
| } |
| #endif /* POLARSSL_ASN1_WRITE_C */ |