/**
* \file asn1.h
*
* \brief Generic ASN.1 parsing
*
* Copyright (C) 2006-2011, 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.
*/
#ifndef POLARSSL_ASN1_H
#define POLARSSL_ASN1_H
#include "config.h"
#if defined(POLARSSL_BIGNUM_C)
#include "bignum.h"
#endif
#include <string.h>
/**
* \addtogroup asn1_module
* \{
*/
/**
* \name ASN1 Error codes
* These error codes are OR'ed to X509 error codes for
* higher error granularity.
* ASN1 is a standard to specify data structures.
* \{
*/
#define POLARSSL_ERR_ASN1_OUT_OF_DATA -0x0060 /**< Out of data when parsing an ASN1 data structure. */
#define POLARSSL_ERR_ASN1_UNEXPECTED_TAG -0x0062 /**< ASN1 tag was of an unexpected value. */
#define POLARSSL_ERR_ASN1_INVALID_LENGTH -0x0064 /**< Error when trying to determine the length or invalid length. */
#define POLARSSL_ERR_ASN1_LENGTH_MISMATCH -0x0066 /**< Actual length differs from expected length. */
#define POLARSSL_ERR_ASN1_INVALID_DATA -0x0068 /**< Data is invalid. (not used) */
#define POLARSSL_ERR_ASN1_MALLOC_FAILED -0x006A /**< Memory allocation failed */
#define POLARSSL_ERR_ASN1_BUF_TOO_SMALL -0x006C /**< Buffer too small when writing ASN.1 data structure. */
/* \} name */
/**
* \name DER constants
* These constants comply with DER encoded the ANS1 type tags.
* DER encoding uses hexadecimal representation.
* An example DER sequence is:\n
* - 0x02 -- tag indicating INTEGER
* - 0x01 -- length in octets
* - 0x05 -- value
* Such sequences are typically read into \c ::x509_buf.
* \{
*/
#define ASN1_BOOLEAN 0x01
#define ASN1_INTEGER 0x02
#define ASN1_BIT_STRING 0x03
#define ASN1_OCTET_STRING 0x04
#define ASN1_NULL 0x05
#define ASN1_OID 0x06
#define ASN1_UTF8_STRING 0x0C
#define ASN1_SEQUENCE 0x10
#define ASN1_SET 0x11
#define ASN1_PRINTABLE_STRING 0x13
#define ASN1_T61_STRING 0x14
#define ASN1_IA5_STRING 0x16
#define ASN1_UTC_TIME 0x17
#define ASN1_GENERALIZED_TIME 0x18
#define ASN1_UNIVERSAL_STRING 0x1C
#define ASN1_BMP_STRING 0x1E
#define ASN1_PRIMITIVE 0x00
#define ASN1_CONSTRUCTED 0x20
#define ASN1_CONTEXT_SPECIFIC 0x80
/* \} name */
/* \} addtogroup asn1_module */
/** Returns the size of the binary string, without the trailing \\0 */
#define OID_SIZE(x) (sizeof(x) - 1)
#ifdef __cplusplus
extern "C" {
#endif
/**
* \name Functions to parse ASN.1 data structures
* \{
*/
/**
* Type-length-value structure that allows for ASN1 using DER.
*/
typedef struct _asn1_buf
{
int tag; /**< ASN1 type, e.g. ASN1_UTF8_STRING. */
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char *p; /**< ASN1 data, e.g. in ASCII. */
}
asn1_buf;
/**
* Container for ASN1 bit strings.
*/
typedef struct _asn1_bitstring
{
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char unused_bits; /**< Number of unused bits at the end of the string */
unsigned char *p; /**< Raw ASN1 data for the bit string */
}
asn1_bitstring;
/**
* Container for a sequence of ASN.1 items
*/
typedef struct _asn1_sequence
{
asn1_buf buf; /**< Buffer containing the given ASN.1 item. */
struct _asn1_sequence *next; /**< The next entry in the sequence. */
}
asn1_sequence;
/**
* Get the length of an ASN.1 element.
* Updates the pointer to immediately behind the length.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param len The variable that will receive the value
*
* \return 0 if successful, POLARSSL_ERR_ASN1_OUT_OF_DATA on reaching
* end of data, POLARSSL_ERR_ASN1_INVALID_LENGTH if length is
* unparseable.
*/
int asn1_get_len( unsigned char **p,
const unsigned char *end,
size_t *len );
/**
* Get the tag and length of the tag. Check for the requested tag.
* Updates the pointer to immediately behind the tag and length.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param len The variable that will receive the length
* \param tag The expected tag
*
* \return 0 if successful, POLARSSL_ERR_ASN1_UNEXPECTED_TAG if tag did
* not match requested tag, or another specific ASN.1 error code.
*/
int asn1_get_tag( unsigned char **p,
const unsigned char *end,
size_t *len, int tag );
/**
* Retrieve a boolean ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param val The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_bool( unsigned char **p,
const unsigned char *end,
int *val );
/**
* Retrieve an integer ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param val The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val );
/**
* Retrieve a bitstring ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param bs The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
asn1_bitstring *bs);
/**
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
* Updated the pointer to immediately behind the full sequence tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param cur First variable in the chain to fill
* \param tag Type of sequence
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
asn1_sequence *cur,
int tag);
#if defined(POLARSSL_BIGNUM_C)
/**
* Retrieve a MPI value from an integer ASN.1 tag.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param X The MPI that will receive the value
*
* \return 0 if successful or a specific ASN.1 or MPI error code.
*/
int asn1_get_mpi( unsigned char **p,
const unsigned char *end,
mpi *X );
#endif
#ifdef __cplusplus
}
#endif
#endif /* asn1.h */