/**
* \file asn1.h
*
* \brief 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)
*/
#ifndef MBEDTLS_ASN1_H
#define MBEDTLS_ASN1_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include <stddef.h>
#if defined(MBEDTLS_BIGNUM_C)
#include "bignum.h"
#endif
/**
* \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 MBEDTLS_ERR_ASN1_OUT_OF_DATA -0x0060 /**< Out of data when parsing an ASN1 data structure. */
#define MBEDTLS_ERR_ASN1_UNEXPECTED_TAG -0x0062 /**< ASN1 tag was of an unexpected value. */
#define MBEDTLS_ERR_ASN1_INVALID_LENGTH -0x0064 /**< Error when trying to determine the length or invalid length. */
#define MBEDTLS_ERR_ASN1_LENGTH_MISMATCH -0x0066 /**< Actual length differs from expected length. */
#define MBEDTLS_ERR_ASN1_INVALID_DATA -0x0068 /**< Data is invalid. (not used) */
#define MBEDTLS_ERR_ASN1_ALLOC_FAILED -0x006A /**< Memory allocation failed */
#define MBEDTLS_ERR_ASN1_BUF_TOO_SMALL -0x006C /**< Buffer too small when writing ASN.1 data structure. */
/* \} name */
/**
* \name DER constants
* These constants comply with the DER encoded ASN.1 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 ::mbedtls_x509_buf.
* \{
*/
#define MBEDTLS_ASN1_BOOLEAN 0x01
#define MBEDTLS_ASN1_INTEGER 0x02
#define MBEDTLS_ASN1_BIT_STRING 0x03
#define MBEDTLS_ASN1_OCTET_STRING 0x04
#define MBEDTLS_ASN1_NULL 0x05
#define MBEDTLS_ASN1_OID 0x06
#define MBEDTLS_ASN1_UTF8_STRING 0x0C
#define MBEDTLS_ASN1_SEQUENCE 0x10
#define MBEDTLS_ASN1_SET 0x11
#define MBEDTLS_ASN1_PRINTABLE_STRING 0x13
#define MBEDTLS_ASN1_T61_STRING 0x14
#define MBEDTLS_ASN1_IA5_STRING 0x16
#define MBEDTLS_ASN1_UTC_TIME 0x17
#define MBEDTLS_ASN1_GENERALIZED_TIME 0x18
#define MBEDTLS_ASN1_UNIVERSAL_STRING 0x1C
#define MBEDTLS_ASN1_BMP_STRING 0x1E
#define MBEDTLS_ASN1_PRIMITIVE 0x00
#define MBEDTLS_ASN1_CONSTRUCTED 0x20
#define MBEDTLS_ASN1_CONTEXT_SPECIFIC 0x80
/*
* Bit masks for each of the components of an ASN.1 tag as specified in
* ITU X.690 (08/2015), section 8.1 "General rules for encoding",
* paragraph 8.1.2.2:
*
* Bit 8 7 6 5 1
* +-------+-----+------------+
* | Class | P/C | Tag number |
* +-------+-----+------------+
*/
#define MBEDTLS_ASN1_TAG_CLASS_MASK 0xC0
#define MBEDTLS_ASN1_TAG_PC_MASK 0x20
#define MBEDTLS_ASN1_TAG_VALUE_MASK 0x1F
/* \} name */
/* \} addtogroup asn1_module */
/** Returns the size of the binary string, without the trailing \\0 */
#define MBEDTLS_OID_SIZE(x) (sizeof(x) - 1)
/**
* Compares an mbedtls_asn1_buf structure to a reference OID.
*
* Only works for 'defined' oid_str values (MBEDTLS_OID_HMAC_SHA1), you cannot use a
* 'unsigned char *oid' here!
*/
#define MBEDTLS_OID_CMP(oid_str, oid_buf) \
( ( MBEDTLS_OID_SIZE(oid_str) != (oid_buf)->len ) || \
memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) != 0 )
#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 mbedtls_asn1_buf
{
int tag; /**< ASN1 type, e.g. MBEDTLS_ASN1_UTF8_STRING. */
size_t len; /**< ASN1 length, in octets. */
unsigned char *p; /**< ASN1 data, e.g. in ASCII. */
}
mbedtls_asn1_buf;
/**
* Container for ASN1 bit strings.
*/
typedef struct mbedtls_asn1_bitstring
{
size_t len; /**< ASN1 length, 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 */
}
mbedtls_asn1_bitstring;
/**
* Container for a sequence of ASN.1 items
*/
typedef struct mbedtls_asn1_sequence
{
mbedtls_asn1_buf buf; /**< Buffer containing the given ASN.1 item. */
struct mbedtls_asn1_sequence *next; /**< The next entry in the sequence. */
}
mbedtls_asn1_sequence;
/**
* Container for a sequence or list of 'named' ASN.1 data items
*/
typedef struct mbedtls_asn1_named_data
{
mbedtls_asn1_buf oid; /**< The object identifier. */
mbedtls_asn1_buf val; /**< The named value. */
struct mbedtls_asn1_named_data *next; /**< The next entry in the sequence. */
unsigned char next_merged; /**< Merge next item into the current one? */
}
mbedtls_asn1_named_data;
/**
* \brief 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, MBEDTLS_ERR_ASN1_OUT_OF_DATA on reaching
* end of data, MBEDTLS_ERR_ASN1_INVALID_LENGTH if length is
* unparseable.
*/
int mbedtls_asn1_get_len( unsigned char **p,
const unsigned char *end,
size_t *len );
/**
* \brief 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, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if tag did
* not match requested tag, or another specific ASN.1 error code.
*/
int mbedtls_asn1_get_tag( unsigned char **p,
const unsigned char *end,
size_t *len, int tag );
/**
* \brief 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 mbedtls_asn1_get_bool( unsigned char **p,
const unsigned char *end,
int *val );
/**
* \brief 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 mbedtls_asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val );
/**
* \brief 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 mbedtls_asn1_get_bitstring( unsigned char **p, const unsigned char *end,
mbedtls_asn1_bitstring *bs);
/**
* \brief Retrieve a bitstring ASN.1 tag without unused bits and its
* value.
* Updates the pointer to the beginning of the bit/octet string.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param len Length of the actual bit/octect string in bytes
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int mbedtls_asn1_get_bitstring_null( unsigned char **p, const unsigned char *end,
size_t *len );
/**
* \brief 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 mbedtls_asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
mbedtls_asn1_sequence *cur,
int tag);
#if defined(MBEDTLS_BIGNUM_C)
/**
* \brief 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 mbedtls_asn1_get_mpi( unsigned char **p,
const unsigned char *end,
mbedtls_mpi *X );
#endif /* MBEDTLS_BIGNUM_C */
/**
* \brief Retrieve an AlgorithmIdentifier ASN.1 sequence.
* Updates the pointer to immediately behind the full
* AlgorithmIdentifier.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param alg The buffer to receive the OID
* \param params The buffer to receive the params (if any)
*
* \return 0 if successful or a specific ASN.1 or MPI error code.
*/
int mbedtls_asn1_get_alg( unsigned char **p,
const unsigned char *end,
mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params );
/**
* \brief Retrieve an AlgorithmIdentifier ASN.1 sequence with NULL or no
* params.
* Updates the pointer to immediately behind the full
* AlgorithmIdentifier.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param alg The buffer to receive the OID
*
* \return 0 if successful or a specific ASN.1 or MPI error code.
*/
int mbedtls_asn1_get_alg_null( unsigned char **p,
const unsigned char *end,
mbedtls_asn1_buf *alg );
/**
* \brief Find a specific named_data entry in a sequence or list based on
* the OID.
*
* \param list The list to seek through
* \param oid The OID to look for
* \param len Size of the OID
*
* \return NULL if not found, or a pointer to the existing entry.
*/
mbedtls_asn1_named_data *mbedtls_asn1_find_named_data( mbedtls_asn1_named_data *list,
const char *oid, size_t len );
/**
* \brief Free a mbedtls_asn1_named_data entry
*
* \param entry The named data entry to free
*/
void mbedtls_asn1_free_named_data( mbedtls_asn1_named_data *entry );
/**
* \brief Free all entries in a mbedtls_asn1_named_data list
* Head will be set to NULL
*
* \param head Pointer to the head of the list of named data entries to free
*/
void mbedtls_asn1_free_named_data_list( mbedtls_asn1_named_data **head );
#ifdef __cplusplus
}
#endif
#endif /* asn1.h */