1 /* Copyright (c) 2014, Google Inc. 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15 #ifndef OPENSSL_HEADER_BYTESTRING_H 16 #define OPENSSL_HEADER_BYTESTRING_H 17 18 #include <openssl/base.h> 19 20 #include <openssl/span.h> 21 22 #if defined(__cplusplus) 23 extern "C" { 24 #endif 25 26 27 // Bytestrings are used for parsing and building TLS and ASN.1 messages. 28 // 29 // A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and 30 // provides utility functions for safely parsing length-prefixed structures 31 // like TLS and ASN.1 from it. 32 // 33 // A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and 34 // provides utility functions for building length-prefixed messages. 35 36 37 // CRYPTO ByteString 38 39 struct cbs_st { 40 const uint8_t *data; 41 size_t len; 42 43 #if !defined(BORINGSSL_NO_CXX) 44 // Allow implicit conversions to and from bssl::Span<const uint8_t>. cbs_stcbs_st45 cbs_st(bssl::Span<const uint8_t> span) 46 : data(span.data()), len(span.size()) {} 47 operator bssl::Span<const uint8_t>() const { 48 return bssl::MakeConstSpan(data, len); 49 } 50 51 // Defining any constructors requires we explicitly default the others. 52 cbs_st() = default; 53 cbs_st(const cbs_st &) = default; 54 #endif 55 }; 56 57 // CBS_init sets |cbs| to point to |data|. It does not take ownership of 58 // |data|. 59 OPENSSL_EXPORT void CBS_init(CBS *cbs, const uint8_t *data, size_t len); 60 61 // CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero 62 // otherwise. 63 OPENSSL_EXPORT int CBS_skip(CBS *cbs, size_t len); 64 65 // CBS_data returns a pointer to the contents of |cbs|. 66 OPENSSL_EXPORT const uint8_t *CBS_data(const CBS *cbs); 67 68 // CBS_len returns the number of bytes remaining in |cbs|. 69 OPENSSL_EXPORT size_t CBS_len(const CBS *cbs); 70 71 // CBS_stow copies the current contents of |cbs| into |*out_ptr| and 72 // |*out_len|. If |*out_ptr| is not NULL, the contents are freed with 73 // OPENSSL_free. It returns one on success and zero on allocation failure. On 74 // success, |*out_ptr| should be freed with OPENSSL_free. If |cbs| is empty, 75 // |*out_ptr| will be NULL. 76 OPENSSL_EXPORT int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len); 77 78 // CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a 79 // NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed 80 // with OPENSSL_free. It returns one on success and zero on allocation 81 // failure. On success, |*out_ptr| should be freed with OPENSSL_free. 82 // 83 // NOTE: If |cbs| contains NUL bytes, the string will be truncated. Call 84 // |CBS_contains_zero_byte(cbs)| to check for NUL bytes. 85 OPENSSL_EXPORT int CBS_strdup(const CBS *cbs, char **out_ptr); 86 87 // CBS_contains_zero_byte returns one if the current contents of |cbs| contains 88 // a NUL byte and zero otherwise. 89 OPENSSL_EXPORT int CBS_contains_zero_byte(const CBS *cbs); 90 91 // CBS_mem_equal compares the current contents of |cbs| with the |len| bytes 92 // starting at |data|. If they're equal, it returns one, otherwise zero. If the 93 // lengths match, it uses a constant-time comparison. 94 OPENSSL_EXPORT int CBS_mem_equal(const CBS *cbs, const uint8_t *data, 95 size_t len); 96 97 // CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It 98 // returns one on success and zero on error. 99 OPENSSL_EXPORT int CBS_get_u8(CBS *cbs, uint8_t *out); 100 101 // CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and 102 // advances |cbs|. It returns one on success and zero on error. 103 OPENSSL_EXPORT int CBS_get_u16(CBS *cbs, uint16_t *out); 104 105 // CBS_get_u16le sets |*out| to the next, little-endian uint16_t from |cbs| and 106 // advances |cbs|. It returns one on success and zero on error. 107 OPENSSL_EXPORT int CBS_get_u16le(CBS *cbs, uint16_t *out); 108 109 // CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and 110 // advances |cbs|. It returns one on success and zero on error. 111 OPENSSL_EXPORT int CBS_get_u24(CBS *cbs, uint32_t *out); 112 113 // CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs| 114 // and advances |cbs|. It returns one on success and zero on error. 115 OPENSSL_EXPORT int CBS_get_u32(CBS *cbs, uint32_t *out); 116 117 // CBS_get_u32le sets |*out| to the next, little-endian uint32_t value from 118 // |cbs| and advances |cbs|. It returns one on success and zero on error. 119 OPENSSL_EXPORT int CBS_get_u32le(CBS *cbs, uint32_t *out); 120 121 // CBS_get_u64 sets |*out| to the next, big-endian uint64_t value from |cbs| 122 // and advances |cbs|. It returns one on success and zero on error. 123 OPENSSL_EXPORT int CBS_get_u64(CBS *cbs, uint64_t *out); 124 125 // CBS_get_u64le sets |*out| to the next, little-endian uint64_t value from 126 // |cbs| and advances |cbs|. It returns one on success and zero on error. 127 OPENSSL_EXPORT int CBS_get_u64le(CBS *cbs, uint64_t *out); 128 129 // CBS_get_last_u8 sets |*out| to the last uint8_t from |cbs| and shortens 130 // |cbs|. It returns one on success and zero on error. 131 OPENSSL_EXPORT int CBS_get_last_u8(CBS *cbs, uint8_t *out); 132 133 // CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances 134 // |cbs|. It returns one on success and zero on error. 135 OPENSSL_EXPORT int CBS_get_bytes(CBS *cbs, CBS *out, size_t len); 136 137 // CBS_copy_bytes copies the next |len| bytes from |cbs| to |out| and advances 138 // |cbs|. It returns one on success and zero on error. 139 OPENSSL_EXPORT int CBS_copy_bytes(CBS *cbs, uint8_t *out, size_t len); 140 141 // CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit, 142 // length-prefixed value from |cbs| and advances |cbs| over it. It returns one 143 // on success and zero on error. 144 OPENSSL_EXPORT int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out); 145 146 // CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit, 147 // big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 148 // returns one on success and zero on error. 149 OPENSSL_EXPORT int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out); 150 151 // CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit, 152 // big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 153 // returns one on success and zero on error. 154 OPENSSL_EXPORT int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out); 155 156 157 // Parsing ASN.1 158 // 159 // |CBS| may be used to parse DER structures. Rather than using a schema 160 // compiler, the following functions act on tag-length-value elements in the 161 // serialization itself. Thus the caller is responsible for looping over a 162 // SEQUENCE, branching on CHOICEs or OPTIONAL fields, checking for trailing 163 // data, and handling explict vs. implicit tagging. 164 // 165 // Tags are represented as |unsigned| values in memory. The upper few bits store 166 // the class and constructed bit, and the remaining bits store the tag 167 // number. Note this differs from the DER serialization, to support tag numbers 168 // beyond 31. Consumers must use the constants defined below to decompose or 169 // assemble tags. 170 // 171 // This library treats an element's constructed bit as part of its tag. In DER, 172 // the constructed bit is computable from the type. The constants for universal 173 // types have the bit set. Callers must set it correctly for tagged types. 174 // Explicitly-tagged types are always constructed, and implicitly-tagged types 175 // inherit the underlying type's bit. 176 177 // CBS_ASN1_TAG_SHIFT is how much the in-memory representation shifts the class 178 // and constructed bits from the DER serialization. 179 #define CBS_ASN1_TAG_SHIFT 24 180 181 // CBS_ASN1_CONSTRUCTED may be ORed into a tag to set the constructed bit. 182 #define CBS_ASN1_CONSTRUCTED (0x20u << CBS_ASN1_TAG_SHIFT) 183 184 // The following values specify the tag class and may be ORed into a tag number 185 // to produce the final tag. If none is used, the tag will be UNIVERSAL. 186 #define CBS_ASN1_UNIVERSAL (0u << CBS_ASN1_TAG_SHIFT) 187 #define CBS_ASN1_APPLICATION (0x40u << CBS_ASN1_TAG_SHIFT) 188 #define CBS_ASN1_CONTEXT_SPECIFIC (0x80u << CBS_ASN1_TAG_SHIFT) 189 #define CBS_ASN1_PRIVATE (0xc0u << CBS_ASN1_TAG_SHIFT) 190 191 // CBS_ASN1_CLASS_MASK may be ANDed with a tag to query its class. This will 192 // give one of the four values above. 193 #define CBS_ASN1_CLASS_MASK (0xc0u << CBS_ASN1_TAG_SHIFT) 194 195 // CBS_ASN1_TAG_NUMBER_MASK may be ANDed with a tag to query its number. 196 #define CBS_ASN1_TAG_NUMBER_MASK ((1u << (5 + CBS_ASN1_TAG_SHIFT)) - 1) 197 198 // The following values are constants for UNIVERSAL tags. Note these constants 199 // include the constructed bit. 200 #define CBS_ASN1_BOOLEAN 0x1u 201 #define CBS_ASN1_INTEGER 0x2u 202 #define CBS_ASN1_BITSTRING 0x3u 203 #define CBS_ASN1_OCTETSTRING 0x4u 204 #define CBS_ASN1_NULL 0x5u 205 #define CBS_ASN1_OBJECT 0x6u 206 #define CBS_ASN1_ENUMERATED 0xau 207 #define CBS_ASN1_UTF8STRING 0xcu 208 #define CBS_ASN1_SEQUENCE (0x10u | CBS_ASN1_CONSTRUCTED) 209 #define CBS_ASN1_SET (0x11u | CBS_ASN1_CONSTRUCTED) 210 #define CBS_ASN1_NUMERICSTRING 0x12u 211 #define CBS_ASN1_PRINTABLESTRING 0x13u 212 #define CBS_ASN1_T61STRING 0x14u 213 #define CBS_ASN1_VIDEOTEXSTRING 0x15u 214 #define CBS_ASN1_IA5STRING 0x16u 215 #define CBS_ASN1_UTCTIME 0x17u 216 #define CBS_ASN1_GENERALIZEDTIME 0x18u 217 #define CBS_ASN1_GRAPHICSTRING 0x19u 218 #define CBS_ASN1_VISIBLESTRING 0x1au 219 #define CBS_ASN1_GENERALSTRING 0x1bu 220 #define CBS_ASN1_UNIVERSALSTRING 0x1cu 221 #define CBS_ASN1_BMPSTRING 0x1eu 222 223 // CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not 224 // including tag and length bytes) and advances |cbs| over it. The ASN.1 225 // element must match |tag_value|. It returns one on success and zero 226 // on error. 227 OPENSSL_EXPORT int CBS_get_asn1(CBS *cbs, CBS *out, unsigned tag_value); 228 229 // CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the 230 // ASN.1 header bytes too. 231 OPENSSL_EXPORT int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value); 232 233 // CBS_peek_asn1_tag looks ahead at the next ASN.1 tag and returns one 234 // if the next ASN.1 element on |cbs| would have tag |tag_value|. If 235 // |cbs| is empty or the tag does not match, it returns zero. Note: if 236 // it returns one, CBS_get_asn1 may still fail if the rest of the 237 // element is malformed. 238 OPENSSL_EXPORT int CBS_peek_asn1_tag(const CBS *cbs, unsigned tag_value); 239 240 // CBS_get_any_asn1 sets |*out| to contain the next ASN.1 element from |*cbs| 241 // (not including tag and length bytes), sets |*out_tag| to the tag number, and 242 // advances |*cbs|. It returns one on success and zero on error. Either of |out| 243 // and |out_tag| may be NULL to ignore the value. 244 OPENSSL_EXPORT int CBS_get_any_asn1(CBS *cbs, CBS *out, unsigned *out_tag); 245 246 // CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from 247 // |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to 248 // the tag number and |*out_header_len| to the length of the ASN.1 header. Each 249 // of |out|, |out_tag|, and |out_header_len| may be NULL to ignore the value. 250 OPENSSL_EXPORT int CBS_get_any_asn1_element(CBS *cbs, CBS *out, 251 unsigned *out_tag, 252 size_t *out_header_len); 253 254 // CBS_get_any_ber_asn1_element acts the same as |CBS_get_any_asn1_element| but 255 // also allows indefinite-length elements to be returned and does not enforce 256 // that lengths are minimal. For indefinite-lengths, |*out_header_len| and 257 // |CBS_len(out)| will be equal as only the header is returned (although this is 258 // also true for empty elements so the length must be checked too). If 259 // |out_ber_found| is not NULL then it is set to one if any case of invalid DER 260 // but valid BER is found, and to zero otherwise. 261 OPENSSL_EXPORT int CBS_get_any_ber_asn1_element(CBS *cbs, CBS *out, 262 unsigned *out_tag, 263 size_t *out_header_len, 264 int *out_ber_found); 265 266 // CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1| 267 // and sets |*out| to its value. It returns one on success and zero on error, 268 // where error includes the integer being negative, or too large to represent 269 // in 64 bits. 270 OPENSSL_EXPORT int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out); 271 272 // CBS_get_asn1_int64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1| 273 // and sets |*out| to its value. It returns one on success and zero on error, 274 // where error includes the integer being too large to represent in 64 bits. 275 OPENSSL_EXPORT int CBS_get_asn1_int64(CBS *cbs, int64_t *out); 276 277 // CBS_get_asn1_bool gets an ASN.1 BOOLEAN from |cbs| and sets |*out| to zero 278 // or one based on its value. It returns one on success or zero on error. 279 OPENSSL_EXPORT int CBS_get_asn1_bool(CBS *cbs, int *out); 280 281 // CBS_get_optional_asn1 gets an optional explicitly-tagged element from |cbs| 282 // tagged with |tag| and sets |*out| to its contents, or ignores it if |out| is 283 // NULL. If present and if |out_present| is not NULL, it sets |*out_present| to 284 // one, otherwise zero. It returns one on success, whether or not the element 285 // was present, and zero on decode failure. 286 OPENSSL_EXPORT int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, 287 unsigned tag); 288 289 // CBS_get_optional_asn1_octet_string gets an optional 290 // explicitly-tagged OCTET STRING from |cbs|. If present, it sets 291 // |*out| to the string and |*out_present| to one. Otherwise, it sets 292 // |*out| to empty and |*out_present| to zero. |out_present| may be 293 // NULL. It returns one on success, whether or not the element was 294 // present, and zero on decode failure. 295 OPENSSL_EXPORT int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, 296 int *out_present, 297 unsigned tag); 298 299 // CBS_get_optional_asn1_uint64 gets an optional explicitly-tagged 300 // INTEGER from |cbs|. If present, it sets |*out| to the 301 // value. Otherwise, it sets |*out| to |default_value|. It returns one 302 // on success, whether or not the element was present, and zero on 303 // decode failure. 304 OPENSSL_EXPORT int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, 305 unsigned tag, 306 uint64_t default_value); 307 308 // CBS_get_optional_asn1_bool gets an optional, explicitly-tagged BOOLEAN from 309 // |cbs|. If present, it sets |*out| to either zero or one, based on the 310 // boolean. Otherwise, it sets |*out| to |default_value|. It returns one on 311 // success, whether or not the element was present, and zero on decode 312 // failure. 313 OPENSSL_EXPORT int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned tag, 314 int default_value); 315 316 // CBS_is_valid_asn1_bitstring returns one if |cbs| is a valid ASN.1 BIT STRING 317 // body and zero otherwise. 318 OPENSSL_EXPORT int CBS_is_valid_asn1_bitstring(const CBS *cbs); 319 320 // CBS_asn1_bitstring_has_bit returns one if |cbs| is a valid ASN.1 BIT STRING 321 // body and the specified bit is present and set. Otherwise, it returns zero. 322 // |bit| is indexed starting from zero. 323 OPENSSL_EXPORT int CBS_asn1_bitstring_has_bit(const CBS *cbs, unsigned bit); 324 325 // CBS_is_valid_asn1_integer returns one if |cbs| is a valid ASN.1 INTEGER, 326 // body and zero otherwise. On success, if |out_is_negative| is non-NULL, 327 // |*out_is_negative| will be set to one if |cbs| is negative and zero 328 // otherwise. 329 OPENSSL_EXPORT int CBS_is_valid_asn1_integer(const CBS *cbs, 330 int *out_is_negative); 331 332 // CBS_is_unsigned_asn1_integer returns one if |cbs| is a valid non-negative 333 // ASN.1 INTEGER body and zero otherwise. 334 OPENSSL_EXPORT int CBS_is_unsigned_asn1_integer(const CBS *cbs); 335 336 // CBS_asn1_oid_to_text interprets |cbs| as DER-encoded ASN.1 OBJECT IDENTIFIER 337 // contents (not including the element framing) and returns the ASCII 338 // representation (e.g., "1.2.840.113554.4.1.72585") in a newly-allocated 339 // string, or NULL on failure. The caller must release the result with 340 // |OPENSSL_free|. 341 OPENSSL_EXPORT char *CBS_asn1_oid_to_text(const CBS *cbs); 342 343 344 // CRYPTO ByteBuilder. 345 // 346 // |CBB| objects allow one to build length-prefixed serialisations. A |CBB| 347 // object is associated with a buffer and new buffers are created with 348 // |CBB_init|. Several |CBB| objects can point at the same buffer when a 349 // length-prefix is pending, however only a single |CBB| can be 'current' at 350 // any one time. For example, if one calls |CBB_add_u8_length_prefixed| then 351 // the new |CBB| points at the same buffer as the original. But if the original 352 // |CBB| is used then the length prefix is written out and the new |CBB| must 353 // not be used again. 354 // 355 // If one needs to force a length prefix to be written out because a |CBB| is 356 // going out of scope, use |CBB_flush|. If an operation on a |CBB| fails, it is 357 // in an undefined state and must not be used except to call |CBB_cleanup|. 358 359 struct cbb_buffer_st { 360 uint8_t *buf; 361 size_t len; // The number of valid bytes. 362 size_t cap; // The size of buf. 363 char can_resize; /* One iff |buf| is owned by this object. If not then |buf| 364 cannot be resized. */ 365 char error; /* One iff there was an error writing to this CBB. All future 366 operations will fail. */ 367 }; 368 369 struct cbb_st { 370 struct cbb_buffer_st *base; 371 // child points to a child CBB if a length-prefix is pending. 372 CBB *child; 373 // offset is the number of bytes from the start of |base->buf| to this |CBB|'s 374 // pending length prefix. 375 size_t offset; 376 // pending_len_len contains the number of bytes in this |CBB|'s pending 377 // length-prefix, or zero if no length-prefix is pending. 378 uint8_t pending_len_len; 379 char pending_is_asn1; 380 // is_child is true iff this is a child |CBB| (as opposed to a top-level 381 // |CBB|). Top-level objects are valid arguments for |CBB_finish|. 382 char is_child; 383 }; 384 385 // CBB_zero sets an uninitialised |cbb| to the zero state. It must be 386 // initialised with |CBB_init| or |CBB_init_fixed| before use, but it is safe to 387 // call |CBB_cleanup| without a successful |CBB_init|. This may be used for more 388 // uniform cleanup of a |CBB|. 389 OPENSSL_EXPORT void CBB_zero(CBB *cbb); 390 391 // CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as 392 // needed, the |initial_capacity| is just a hint. It returns one on success or 393 // zero on allocation failure. 394 OPENSSL_EXPORT int CBB_init(CBB *cbb, size_t initial_capacity); 395 396 // CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since 397 // |buf| cannot grow, trying to write more than |len| bytes will cause CBB 398 // functions to fail. It returns one on success or zero on error. 399 OPENSSL_EXPORT int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len); 400 401 // CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects 402 // writing to the same buffer. This should be used in an error case where a 403 // serialisation is abandoned. 404 // 405 // This function can only be called on a "top level" |CBB|, i.e. one initialised 406 // with |CBB_init| or |CBB_init_fixed|, or a |CBB| set to the zero state with 407 // |CBB_zero|. 408 OPENSSL_EXPORT void CBB_cleanup(CBB *cbb); 409 410 // CBB_finish completes any pending length prefix and sets |*out_data| to a 411 // malloced buffer and |*out_len| to the length of that buffer. The caller 412 // takes ownership of the buffer and, unless the buffer was fixed with 413 // |CBB_init_fixed|, must call |OPENSSL_free| when done. 414 // 415 // It can only be called on a "top level" |CBB|, i.e. one initialised with 416 // |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on 417 // error. 418 OPENSSL_EXPORT int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len); 419 420 // CBB_flush causes any pending length prefixes to be written out and any child 421 // |CBB| objects of |cbb| to be invalidated. This allows |cbb| to continue to be 422 // used after the children go out of scope, e.g. when local |CBB| objects are 423 // added as children to a |CBB| that persists after a function returns. This 424 // function returns one on success or zero on error. 425 OPENSSL_EXPORT int CBB_flush(CBB *cbb); 426 427 // CBB_data returns a pointer to the bytes written to |cbb|. It does not flush 428 // |cbb|. The pointer is valid until the next operation to |cbb|. 429 // 430 // To avoid unfinalized length prefixes, it is a fatal error to call this on a 431 // CBB with any active children. 432 OPENSSL_EXPORT const uint8_t *CBB_data(const CBB *cbb); 433 434 // CBB_len returns the number of bytes written to |cbb|. It does not flush 435 // |cbb|. 436 // 437 // To avoid unfinalized length prefixes, it is a fatal error to call this on a 438 // CBB with any active children. 439 OPENSSL_EXPORT size_t CBB_len(const CBB *cbb); 440 441 // CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The 442 // data written to |*out_contents| will be prefixed in |cbb| with an 8-bit 443 // length. It returns one on success or zero on error. 444 OPENSSL_EXPORT int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents); 445 446 // CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|. 447 // The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit, 448 // big-endian length. It returns one on success or zero on error. 449 OPENSSL_EXPORT int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents); 450 451 // CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|. 452 // The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit, 453 // big-endian length. It returns one on success or zero on error. 454 OPENSSL_EXPORT int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents); 455 456 // CBB_add_asn1 sets |*out_contents| to a |CBB| into which the contents of an 457 // ASN.1 object can be written. The |tag| argument will be used as the tag for 458 // the object. It returns one on success or zero on error. 459 OPENSSL_EXPORT int CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned tag); 460 461 // CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on 462 // success and zero otherwise. 463 OPENSSL_EXPORT int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len); 464 465 // CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to 466 // the beginning of that space. The caller must then write |len| bytes of 467 // actual contents to |*out_data|. It returns one on success and zero 468 // otherwise. 469 OPENSSL_EXPORT int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len); 470 471 // CBB_reserve ensures |cbb| has room for |len| additional bytes and sets 472 // |*out_data| to point to the beginning of that space. It returns one on 473 // success and zero otherwise. The caller may write up to |len| bytes to 474 // |*out_data| and call |CBB_did_write| to complete the write. |*out_data| is 475 // valid until the next operation on |cbb| or an ancestor |CBB|. 476 OPENSSL_EXPORT int CBB_reserve(CBB *cbb, uint8_t **out_data, size_t len); 477 478 // CBB_did_write advances |cbb| by |len| bytes, assuming the space has been 479 // written to by the caller. It returns one on success and zero on error. 480 OPENSSL_EXPORT int CBB_did_write(CBB *cbb, size_t len); 481 482 // CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on 483 // success and zero otherwise. 484 OPENSSL_EXPORT int CBB_add_u8(CBB *cbb, uint8_t value); 485 486 // CBB_add_u16 appends a 16-bit, big-endian number from |value| to |cbb|. It 487 // returns one on success and zero otherwise. 488 OPENSSL_EXPORT int CBB_add_u16(CBB *cbb, uint16_t value); 489 490 // CBB_add_u16le appends a 16-bit, little-endian number from |value| to |cbb|. 491 // It returns one on success and zero otherwise. 492 OPENSSL_EXPORT int CBB_add_u16le(CBB *cbb, uint16_t value); 493 494 // CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It 495 // returns one on success and zero otherwise. 496 OPENSSL_EXPORT int CBB_add_u24(CBB *cbb, uint32_t value); 497 498 // CBB_add_u32 appends a 32-bit, big-endian number from |value| to |cbb|. It 499 // returns one on success and zero otherwise. 500 OPENSSL_EXPORT int CBB_add_u32(CBB *cbb, uint32_t value); 501 502 // CBB_add_u32le appends a 32-bit, little-endian number from |value| to |cbb|. 503 // It returns one on success and zero otherwise. 504 OPENSSL_EXPORT int CBB_add_u32le(CBB *cbb, uint32_t value); 505 506 // CBB_add_u64 appends a 64-bit, big-endian number from |value| to |cbb|. It 507 // returns one on success and zero otherwise. 508 OPENSSL_EXPORT int CBB_add_u64(CBB *cbb, uint64_t value); 509 510 // CBB_add_u64le appends a 64-bit, little-endian number from |value| to |cbb|. 511 // It returns one on success and zero otherwise. 512 OPENSSL_EXPORT int CBB_add_u64le(CBB *cbb, uint64_t value); 513 514 // CBB_discard_child discards the current unflushed child of |cbb|. Neither the 515 // child's contents nor the length prefix will be included in the output. 516 OPENSSL_EXPORT void CBB_discard_child(CBB *cbb); 517 518 // CBB_add_asn1_uint64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1| 519 // and writes |value| in its contents. It returns one on success and zero on 520 // error. 521 OPENSSL_EXPORT int CBB_add_asn1_uint64(CBB *cbb, uint64_t value); 522 523 // CBB_add_asn1_int64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1| 524 // and writes |value| in its contents. It returns one on success and zero on 525 // error. 526 OPENSSL_EXPORT int CBB_add_asn1_int64(CBB *cbb, int64_t value); 527 528 // CBB_add_asn1_octet_string writes an ASN.1 OCTET STRING into |cbb| with the 529 // given contents. It returns one on success and zero on error. 530 OPENSSL_EXPORT int CBB_add_asn1_octet_string(CBB *cbb, const uint8_t *data, 531 size_t data_len); 532 533 // CBB_add_asn1_bool writes an ASN.1 BOOLEAN into |cbb| which is true iff 534 // |value| is non-zero. It returns one on success and zero on error. 535 OPENSSL_EXPORT int CBB_add_asn1_bool(CBB *cbb, int value); 536 537 // CBB_add_asn1_oid_from_text decodes |len| bytes from |text| as an ASCII OID 538 // representation, e.g. "1.2.840.113554.4.1.72585", and writes the DER-encoded 539 // contents to |cbb|. It returns one on success and zero on malloc failure or if 540 // |text| was invalid. It does not include the OBJECT IDENTIFER framing, only 541 // the element's contents. 542 // 543 // This function considers OID strings with components which do not fit in a 544 // |uint64_t| to be invalid. 545 OPENSSL_EXPORT int CBB_add_asn1_oid_from_text(CBB *cbb, const char *text, 546 size_t len); 547 548 // CBB_flush_asn1_set_of calls |CBB_flush| on |cbb| and then reorders the 549 // contents for a DER-encoded ASN.1 SET OF type. It returns one on success and 550 // zero on failure. DER canonicalizes SET OF contents by sorting 551 // lexicographically by encoding. Call this function when encoding a SET OF 552 // type in an order that is not already known to be canonical. 553 // 554 // Note a SET type has a slightly different ordering than a SET OF. 555 OPENSSL_EXPORT int CBB_flush_asn1_set_of(CBB *cbb); 556 557 558 #if defined(__cplusplus) 559 } // extern C 560 561 562 #if !defined(BORINGSSL_NO_CXX) 563 extern "C++" { 564 565 BSSL_NAMESPACE_BEGIN 566 567 using ScopedCBB = internal::StackAllocated<CBB, void, CBB_zero, CBB_cleanup>; 568 569 BSSL_NAMESPACE_END 570 571 } // extern C++ 572 #endif 573 574 #endif 575 576 #endif // OPENSSL_HEADER_BYTESTRING_H 577