/**
* \file asn1write.h
*
* \brief ASN.1 buffer writing functionality
*/
/*
* Copyright The Mbed TLS Contributors
* 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.
*/
#ifndef MBEDTLS_ASN1_WRITE_H
#define MBEDTLS_ASN1_WRITE_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "mbedtls/asn1.h"
/**
* \addtogroup mbedtls
* \{
* \defgroup mbedtls_asn1write_module ASN.1 Write
* \{
*/
#define MBEDTLS_ASN1_CHK_ADD(g, f) \
do \
{ \
if( ( ret = (f) ) < 0 ) \
return( ret ); \
else \
(g) += ret; \
} while( 0 )
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Write a length field in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param len The length value to write.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start,
size_t len );
/**
* \brief Write an ASN.1 tag in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param tag The tag to write.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start,
unsigned char tag );
/**
* \brief Write raw buffer data.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param buf The data buffer to write.
* \param size The length of the data buffer.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t size );
#if defined(MBEDTLS_BIGNUM_C)
/**
* \brief Write a arbitrary-precision number (#MBEDTLS_ASN1_INTEGER)
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param X The MPI to write.
* It must be non-negative.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start,
const mbedtls_mpi *X );
#endif /* MBEDTLS_BIGNUM_C */
/**
* \brief Write a NULL tag (#MBEDTLS_ASN1_NULL) with zero data
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start );
/**
* \brief Write an OID tag (#MBEDTLS_ASN1_OID) and data
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param oid The OID to write.
* \param oid_len The length of the OID.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len );
/**
* \brief Write an AlgorithmIdentifier sequence in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param oid The OID of the algorithm to write.
* \param oid_len The length of the algorithm's OID.
* \param par_len The length of the parameters, which must be already written.
* If 0, NULL parameters are added
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_algorithm_identifier( unsigned char **p,
unsigned char *start,
const char *oid, size_t oid_len,
size_t par_len );
/**
* \brief Write a boolean tag (#MBEDTLS_ASN1_BOOLEAN) and value
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param boolean The boolean value to write, either \c 0 or \c 1.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start,
int boolean );
/**
* \brief Write an int tag (#MBEDTLS_ASN1_INTEGER) and value
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param val The integer value to write.
* It must be non-negative.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val );
/**
* \brief Write an enum tag (#MBEDTLS_ASN1_ENUMERATED) and value
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param val The integer value to write.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_enum( unsigned char **p, unsigned char *start, int val );
/**
* \brief Write a string in ASN.1 format using a specific
* string encoding tag.
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param tag The string encoding tag to write, e.g.
* #MBEDTLS_ASN1_UTF8_STRING.
* \param text The string to write.
* \param text_len The length of \p text in bytes (which might
* be strictly larger than the number of characters).
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_tagged_string( unsigned char **p, unsigned char *start,
int tag, const char *text,
size_t text_len );
/**
* \brief Write a string in ASN.1 format using the PrintableString
* string encoding tag (#MBEDTLS_ASN1_PRINTABLE_STRING).
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param text The string to write.
* \param text_len The length of \p text in bytes (which might
* be strictly larger than the number of characters).
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_printable_string( unsigned char **p,
unsigned char *start,
const char *text, size_t text_len );
/**
* \brief Write a UTF8 string in ASN.1 format using the UTF8String
* string encoding tag (#MBEDTLS_ASN1_UTF8_STRING).
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param text The string to write.
* \param text_len The length of \p text in bytes (which might
* be strictly larger than the number of characters).
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_utf8_string( unsigned char **p, unsigned char *start,
const char *text, size_t text_len );
/**
* \brief Write a string in ASN.1 format using the IA5String
* string encoding tag (#MBEDTLS_ASN1_IA5_STRING).
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param text The string to write.
* \param text_len The length of \p text in bytes (which might
* be strictly larger than the number of characters).
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
const char *text, size_t text_len );
/**
* \brief Write a bitstring tag (#MBEDTLS_ASN1_BIT_STRING) and
* value in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param buf The bitstring to write.
* \param bits The total number of bits in the bitstring.
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t bits );
/**
* \brief This function writes a named bitstring tag
* (#MBEDTLS_ASN1_BIT_STRING) and value in ASN.1 format.
*
* As stated in RFC 5280 Appendix B, trailing zeroes are
* omitted when encoding named bitstrings in DER.
*
* \note This function works backwards within the data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer which is used for bounds-checking.
* \param buf The bitstring to write.
* \param bits The total number of bits in the bitstring.
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_named_bitstring( unsigned char **p,
unsigned char *start,
const unsigned char *buf,
size_t bits );
/**
* \brief Write an octet string tag (#MBEDTLS_ASN1_OCTET_STRING)
* and value in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param buf The buffer holding the data to write.
* \param size The length of the data buffer \p buf.
*
* \return The number of bytes written to \p p on success.
* \return A negative error code on failure.
*/
int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t size );
/**
* \brief Create or find a specific named_data entry for writing in a
* sequence or list based on the OID. If not already in there,
* a new entry is added to the head of the list.
* Warning: Destructive behaviour for the val data!
*
* \param list The pointer to the location of the head of the list to seek
* through (will be updated in case of a new entry).
* \param oid The OID to look for.
* \param oid_len The size of the OID.
* \param val The associated data to store. If this is \c NULL,
* no data is copied to the new or existing buffer.
* \param val_len The minimum length of the data buffer needed.
* If this is 0, do not allocate a buffer for the associated
* data.
* If the OID was already present, enlarge, shrink or free
* the existing buffer to fit \p val_len.
*
* \return A pointer to the new / existing entry on success.
* \return \c NULL if if there was a memory allocation error.
*/
mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data **list,
const char *oid, size_t oid_len,
const unsigned char *val,
size_t val_len );
/// \}
/// \}
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_ASN1_WRITE_H */
