1 /** 2 * \file asn1write.h 3 * 4 * \brief ASN.1 buffer writing functionality 5 */ 6 /* 7 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 8 * SPDX-License-Identifier: Apache-2.0 9 * 10 * Licensed under the Apache License, Version 2.0 (the "License"); you may 11 * not use this file except in compliance with the License. 12 * You may obtain a copy of the License at 13 * 14 * http://www.apache.org/licenses/LICENSE-2.0 15 * 16 * Unless required by applicable law or agreed to in writing, software 17 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 18 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 19 * See the License for the specific language governing permissions and 20 * limitations under the License. 21 * 22 * This file is part of mbed TLS (https://tls.mbed.org) 23 */ 24 #ifndef MBEDTLS_ASN1_WRITE_H 25 #define MBEDTLS_ASN1_WRITE_H 26 27 #include "asn1.h" 28 29 #define MBEDTLS_ASN1_CHK_ADD(g, f) \ 30 do { \ 31 if( ( ret = f ) < 0 ) \ 32 return( ret ); \ 33 else \ 34 g += ret; \ 35 } while( 0 ) 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /** 42 * \brief Write a length field in ASN.1 format. 43 * 44 * \note This function works backwards in data buffer. 45 * 46 * \param p The reference to the current position pointer. 47 * \param start The start of the buffer, for bounds-checking. 48 * \param len The length value to write. 49 * 50 * \return The number of bytes written to \p p on success. 51 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 52 */ 53 int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start, 54 size_t len ); 55 /** 56 * \brief Write an ASN.1 tag in ASN.1 format. 57 * 58 * \note This function works backwards in data buffer. 59 * 60 * \param p The reference to the current position pointer. 61 * \param start The start of the buffer, for bounds-checking. 62 * \param tag The tag to write. 63 * 64 * \return The number of bytes written to \p p on success. 65 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 66 */ 67 int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start, 68 unsigned char tag ); 69 70 /** 71 * \brief Write raw buffer data. 72 * 73 * \note This function works backwards in data buffer. 74 * 75 * \param p The reference to the current position pointer. 76 * \param start The start of the buffer, for bounds-checking. 77 * \param buf The data buffer to write. 78 * \param size The length of the data buffer. 79 * 80 * \return The number of bytes written to \p p on success. 81 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 82 */ 83 int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start, 84 const unsigned char *buf, size_t size ); 85 86 #if defined(MBEDTLS_BIGNUM_C) 87 /** 88 * \brief Write a arbitrary-precision number (#MBEDTLS_ASN1_INTEGER) 89 * in ASN.1 format. 90 * 91 * \note This function works backwards in data buffer. 92 * 93 * \param p The reference to the current position pointer. 94 * \param start The start of the buffer, for bounds-checking. 95 * \param X The MPI to write. 96 * 97 * \return The number of bytes written to \p p on success. 98 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 99 */ 100 int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, 101 const mbedtls_mpi *X ); 102 #endif /* MBEDTLS_BIGNUM_C */ 103 104 /** 105 * \brief Write a NULL tag (#MBEDTLS_ASN1_NULL) with zero data 106 * in ASN.1 format. 107 * 108 * \note This function works backwards in data buffer. 109 * 110 * \param p The reference to the current position pointer. 111 * \param start The start of the buffer, for bounds-checking. 112 * 113 * \return The number of bytes written to \p p on success. 114 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 115 */ 116 int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start ); 117 118 /** 119 * \brief Write an OID tag (#MBEDTLS_ASN1_OID) and data 120 * in ASN.1 format. 121 * 122 * \note This function works backwards in data buffer. 123 * 124 * \param p The reference to the current position pointer. 125 * \param start The start of the buffer, for bounds-checking. 126 * \param oid The OID to write. 127 * \param oid_len The length of the OID. 128 * 129 * \return The number of bytes written to \p p on success. 130 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 131 */ 132 int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start, 133 const char *oid, size_t oid_len ); 134 135 /** 136 * \brief Write an AlgorithmIdentifier sequence in ASN.1 format. 137 * 138 * \note This function works backwards in data buffer. 139 * 140 * \param p The reference to the current position pointer. 141 * \param start The start of the buffer, for bounds-checking. 142 * \param oid The OID of the algorithm to write. 143 * \param oid_len The length of the algorithm's OID. 144 * \param par_len The length of the parameters, which must be already written. 145 * If 0, NULL parameters are added 146 * 147 * \return The number of bytes written to \p p on success. 148 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 149 */ 150 int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, 151 unsigned char *start, 152 const char *oid, size_t oid_len, 153 size_t par_len ); 154 155 /** 156 * \brief Write a boolean tag (#MBEDTLS_ASN1_BOOLEAN) and value 157 * in ASN.1 format. 158 * 159 * \note This function works backwards in data buffer. 160 * 161 * \param p The reference to the current position pointer. 162 * \param start The start of the buffer, for bounds-checking. 163 * \param boolean The boolean value to write, either \c 0 or \c 1. 164 * 165 * \return The number of bytes written to \p p on success. 166 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 167 */ 168 int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, 169 int boolean ); 170 171 /** 172 * \brief Write an int tag (#MBEDTLS_ASN1_INTEGER) and value 173 * in ASN.1 format. 174 * 175 * \note This function works backwards in data buffer. 176 * 177 * \param p The reference to the current position pointer. 178 * \param start The start of the buffer, for bounds-checking. 179 * \param val The integer value to write. 180 * 181 * \return The number of bytes written to \p p on success. 182 * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. 183 */ 184 int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val ); 185 186 /** 187 * \brief Write a string in ASN.1 format using a specific 188 * string encoding tag. 189 190 * \note This function works backwards in data buffer. 191 * 192 * \param p The reference to the current position pointer. 193 * \param start The start of the buffer, for bounds-checking. 194 * \param tag The string encoding tag to write, e.g. 195 * #MBEDTLS_ASN1_UTF8_STRING. 196 * \param text The string to write. 197 * \param text_len The length of \p text in bytes (which might 198 * be strictly larger than the number of characters). 199 * 200 * \return The number of bytes written to \p p on success. 201 * \return A negative error code on failure. 202 */ 203 int mbedtls_asn1_write_tagged_string( unsigned char **p, unsigned char *start, 204 int tag, const char *text, 205 size_t text_len ); 206 207 /** 208 * \brief Write a string in ASN.1 format using the PrintableString 209 * string encoding tag (#MBEDTLS_ASN1_PRINTABLE_STRING). 210 * 211 * \note This function works backwards in data buffer. 212 * 213 * \param p The reference to the current position pointer. 214 * \param start The start of the buffer, for bounds-checking. 215 * \param text The string to write. 216 * \param text_len The length of \p text in bytes (which might 217 * be strictly larger than the number of characters). 218 * 219 * \return The number of bytes written to \p p on success. 220 * \return A negative error code on failure. 221 */ 222 int mbedtls_asn1_write_printable_string( unsigned char **p, 223 unsigned char *start, 224 const char *text, size_t text_len ); 225 226 /** 227 * \brief Write a UTF8 string in ASN.1 format using the UTF8String 228 * string encoding tag (#MBEDTLS_ASN1_PRINTABLE_STRING). 229 * 230 * \note This function works backwards in data buffer. 231 * 232 * \param p The reference to the current position pointer. 233 * \param start The start of the buffer, for bounds-checking. 234 * \param text The string to write. 235 * \param text_len The length of \p text in bytes (which might 236 * be strictly larger than the number of characters). 237 * 238 * \return The number of bytes written to \p p on success. 239 * \return A negative error code on failure. 240 */ 241 int mbedtls_asn1_write_utf8_string( unsigned char **p, unsigned char *start, 242 const char *text, size_t text_len ); 243 244 /** 245 * \brief Write a string in ASN.1 format using the IA5String 246 * string encoding tag (#MBEDTLS_ASN1_IA5_STRING). 247 * 248 * \note This function works backwards in data buffer. 249 * 250 * \param p The reference to the current position pointer. 251 * \param start The start of the buffer, for bounds-checking. 252 * \param text The string to write. 253 * \param text_len The length of \p text in bytes (which might 254 * be strictly larger than the number of characters). 255 * 256 * \return The number of bytes written to \p p on success. 257 * \return A negative error code on failure. 258 */ 259 int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start, 260 const char *text, size_t text_len ); 261 262 /** 263 * \brief Write a bitstring tag (#MBEDTLS_ASN1_BIT_STRING) and 264 * value in ASN.1 format. 265 * 266 * \note This function works backwards in data buffer. 267 * 268 * \param p The reference to the current position pointer. 269 * \param start The start of the buffer, for bounds-checking. 270 * \param buf The bitstring to write. 271 * \param bits The total number of bits in the bitstring. 272 * 273 * \return The number of bytes written to \p p on success. 274 * \return A negative error code on failure. 275 */ 276 int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start, 277 const unsigned char *buf, size_t bits ); 278 279 /** 280 * \brief Write an octet string tag (#MBEDTLS_ASN1_OCTET_STRING) 281 * and value in ASN.1 format. 282 * 283 * \note This function works backwards in data buffer. 284 * 285 * \param p The reference to the current position pointer. 286 * \param start The start of the buffer, for bounds-checking. 287 * \param buf The buffer holding the data to write. 288 * \param size The length of the data buffer \p buf. 289 * 290 * \return The number of bytes written to \p p on success. 291 * \return A negative error code on failure. 292 */ 293 int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start, 294 const unsigned char *buf, size_t size ); 295 296 /** 297 * \brief Create or find a specific named_data entry for writing in a 298 * sequence or list based on the OID. If not already in there, 299 * a new entry is added to the head of the list. 300 * Warning: Destructive behaviour for the val data! 301 * 302 * \param list The pointer to the location of the head of the list to seek 303 * through (will be updated in case of a new entry). 304 * \param oid The OID to look for. 305 * \param oid_len The size of the OID. 306 * \param val The data to store (can be \c NULL if you want to fill 307 * it by hand). 308 * \param val_len The minimum length of the data buffer needed. 309 * 310 * \return A pointer to the new / existing entry on success. 311 * \return \c NULL if if there was a memory allocation error. 312 */ 313 mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data **list, 314 const char *oid, size_t oid_len, 315 const unsigned char *val, 316 size_t val_len ); 317 318 #ifdef __cplusplus 319 } 320 #endif 321 322 #endif /* MBEDTLS_ASN1_WRITE_H */ 323