Home | History | Annotate | Download | only in openssl
      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 #if defined(__cplusplus)
     21 extern "C" {
     22 #endif
     23 
     24 
     25 /* Bytestrings are used for parsing and building TLS and ASN.1 messages.
     26  *
     27  * A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and
     28  * provides utility functions for safely parsing length-prefixed structures
     29  * like TLS and ASN.1 from it.
     30  *
     31  * A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and
     32  * provides utility functions for building length-prefixed messages. */
     33 
     34 
     35 /* CRYPTO ByteString */
     36 
     37 struct cbs_st {
     38   const uint8_t *data;
     39   size_t len;
     40 };
     41 
     42 /* CBS_init sets |cbs| to point to |data|. It does not take ownership of
     43  * |data|. */
     44 OPENSSL_EXPORT void CBS_init(CBS *cbs, const uint8_t *data, size_t len);
     45 
     46 /* CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero
     47  * otherwise. */
     48 OPENSSL_EXPORT int CBS_skip(CBS *cbs, size_t len);
     49 
     50 /* CBS_data returns a pointer to the contents of |cbs|. */
     51 OPENSSL_EXPORT const uint8_t *CBS_data(const CBS *cbs);
     52 
     53 /* CBS_len returns the number of bytes remaining in |cbs|. */
     54 OPENSSL_EXPORT size_t CBS_len(const CBS *cbs);
     55 
     56 /* CBS_stow copies the current contents of |cbs| into |*out_ptr| and
     57  * |*out_len|. If |*out_ptr| is not NULL, the contents are freed with
     58  * OPENSSL_free. It returns one on success and zero on allocation failure. On
     59  * success, |*out_ptr| should be freed with OPENSSL_free. If |cbs| is empty,
     60  * |*out_ptr| will be NULL. */
     61 OPENSSL_EXPORT int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len);
     62 
     63 /* CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a
     64  * NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed
     65  * with OPENSSL_free. It returns one on success and zero on allocation
     66  * failure. On success, |*out_ptr| should be freed with OPENSSL_free.
     67  *
     68  * NOTE: If |cbs| contains NUL bytes, the string will be truncated. Call
     69  * |CBS_contains_zero_byte(cbs)| to check for NUL bytes. */
     70 OPENSSL_EXPORT int CBS_strdup(const CBS *cbs, char **out_ptr);
     71 
     72 /* CBS_contains_zero_byte returns one if the current contents of |cbs| contains
     73  * a NUL byte and zero otherwise. */
     74 OPENSSL_EXPORT int CBS_contains_zero_byte(const CBS *cbs);
     75 
     76 /* CBS_mem_equal compares the current contents of |cbs| with the |len| bytes
     77  * starting at |data|. If they're equal, it returns one, otherwise zero. If the
     78  * lengths match, it uses a constant-time comparison. */
     79 OPENSSL_EXPORT int CBS_mem_equal(const CBS *cbs, const uint8_t *data,
     80                                  size_t len);
     81 
     82 /* CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It
     83  * returns one on success and zero on error. */
     84 OPENSSL_EXPORT int CBS_get_u8(CBS *cbs, uint8_t *out);
     85 
     86 /* CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and
     87  * advances |cbs|. It returns one on success and zero on error. */
     88 OPENSSL_EXPORT int CBS_get_u16(CBS *cbs, uint16_t *out);
     89 
     90 /* CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and
     91  * advances |cbs|. It returns one on success and zero on error. */
     92 OPENSSL_EXPORT int CBS_get_u24(CBS *cbs, uint32_t *out);
     93 
     94 /* CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs|
     95  * and advances |cbs|. It returns one on success and zero on error. */
     96 OPENSSL_EXPORT int CBS_get_u32(CBS *cbs, uint32_t *out);
     97 
     98 /* CBS_get_last_u8 sets |*out| to the last uint8_t from |cbs| and shortens
     99  * |cbs|. It returns one on success and zero on error. */
    100 OPENSSL_EXPORT int CBS_get_last_u8(CBS *cbs, uint8_t *out);
    101 
    102 /* CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances
    103  * |cbs|. It returns one on success and zero on error. */
    104 OPENSSL_EXPORT int CBS_get_bytes(CBS *cbs, CBS *out, size_t len);
    105 
    106 /* CBS_copy_bytes copies the next |len| bytes from |cbs| to |out| and advances
    107  * |cbs|. It returns one on success and zero on error. */
    108 OPENSSL_EXPORT int CBS_copy_bytes(CBS *cbs, uint8_t *out, size_t len);
    109 
    110 /* CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit,
    111  * length-prefixed value from |cbs| and advances |cbs| over it. It returns one
    112  * on success and zero on error. */
    113 OPENSSL_EXPORT int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out);
    114 
    115 /* CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit,
    116  * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It
    117  * returns one on success and zero on error. */
    118 OPENSSL_EXPORT int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out);
    119 
    120 /* CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit,
    121  * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It
    122  * returns one on success and zero on error. */
    123 OPENSSL_EXPORT int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out);
    124 
    125 
    126 /* Parsing ASN.1 */
    127 
    128 /* The following values are tag numbers for UNIVERSAL elements. */
    129 #define CBS_ASN1_BOOLEAN 0x1
    130 #define CBS_ASN1_INTEGER 0x2
    131 #define CBS_ASN1_BITSTRING 0x3
    132 #define CBS_ASN1_OCTETSTRING 0x4
    133 #define CBS_ASN1_NULL 0x5
    134 #define CBS_ASN1_OBJECT 0x6
    135 #define CBS_ASN1_ENUMERATED 0xa
    136 #define CBS_ASN1_UTF8STRING 0xc
    137 #define CBS_ASN1_SEQUENCE (0x10 | CBS_ASN1_CONSTRUCTED)
    138 #define CBS_ASN1_SET (0x11 | CBS_ASN1_CONSTRUCTED)
    139 #define CBS_ASN1_NUMERICSTRING 0x12
    140 #define CBS_ASN1_PRINTABLESTRING 0x13
    141 #define CBS_ASN1_T61STRING 0x14
    142 #define CBS_ASN1_VIDEOTEXSTRING 0x15
    143 #define CBS_ASN1_IA5STRING 0x16
    144 #define CBS_ASN1_UTCTIME 0x17
    145 #define CBS_ASN1_GENERALIZEDTIME 0x18
    146 #define CBS_ASN1_GRAPHICSTRING 0x19
    147 #define CBS_ASN1_VISIBLESTRING 0x1a
    148 #define CBS_ASN1_GENERALSTRING 0x1b
    149 #define CBS_ASN1_UNIVERSALSTRING 0x1c
    150 #define CBS_ASN1_BMPSTRING 0x1e
    151 
    152 /* CBS_ASN1_CONSTRUCTED may be ORed into a tag to toggle the constructed
    153  * bit. |CBS| and |CBB| APIs consider the constructed bit to be part of the
    154  * tag. */
    155 #define CBS_ASN1_CONSTRUCTED 0x20
    156 
    157 /* The following values specify the constructed bit or tag class and may be ORed
    158  * into a tag number to produce the final tag. If none is used, the tag will be
    159  * UNIVERSAL.
    160  *
    161  * Note that although they currently match the DER serialization, consumers must
    162  * use these bits rather than make assumptions about the representation. This is
    163  * to allow for tag numbers beyond 31 in the future. */
    164 #define CBS_ASN1_APPLICATION 0x40
    165 #define CBS_ASN1_CONTEXT_SPECIFIC 0x80
    166 #define CBS_ASN1_PRIVATE 0xc0
    167 
    168 /* CBS_ASN1_CLASS_MASK may be ANDed with a tag to query its class. */
    169 #define CBS_ASN1_CLASS_MASK 0xc0
    170 
    171 /* CBS_ASN1_TAG_NUMBER_MASK may be ANDed with a tag to query its number. */
    172 #define CBS_ASN1_TAG_NUMBER_MASK 0x1f
    173 
    174 /* CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not
    175  * including tag and length bytes) and advances |cbs| over it. The ASN.1
    176  * element must match |tag_value|. It returns one on success and zero
    177  * on error.
    178  *
    179  * Tag numbers greater than 30 are not supported (i.e. short form only). */
    180 OPENSSL_EXPORT int CBS_get_asn1(CBS *cbs, CBS *out, unsigned tag_value);
    181 
    182 /* CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the
    183  * ASN.1 header bytes too. */
    184 OPENSSL_EXPORT int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value);
    185 
    186 /* CBS_peek_asn1_tag looks ahead at the next ASN.1 tag and returns one
    187  * if the next ASN.1 element on |cbs| would have tag |tag_value|. If
    188  * |cbs| is empty or the tag does not match, it returns zero. Note: if
    189  * it returns one, CBS_get_asn1 may still fail if the rest of the
    190  * element is malformed. */
    191 OPENSSL_EXPORT int CBS_peek_asn1_tag(const CBS *cbs, unsigned tag_value);
    192 
    193 /* CBS_get_any_asn1 sets |*out| to contain the next ASN.1 element from |*cbs|
    194  * (not including tag and length bytes), sets |*out_tag| to the tag number, and
    195  * advances |*cbs|. It returns one on success and zero on error. Either of |out|
    196  * and |out_tag| may be NULL to ignore the value.
    197  *
    198  * Tag numbers greater than 30 are not supported (i.e. short form only). */
    199 OPENSSL_EXPORT int CBS_get_any_asn1(CBS *cbs, CBS *out, unsigned *out_tag);
    200 
    201 /* CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
    202  * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to
    203  * the tag number and |*out_header_len| to the length of the ASN.1 header. Each
    204  * of |out|, |out_tag|, and |out_header_len| may be NULL to ignore the value.
    205  *
    206  * Tag numbers greater than 30 are not supported (i.e. short form only). */
    207 OPENSSL_EXPORT int CBS_get_any_asn1_element(CBS *cbs, CBS *out,
    208                                             unsigned *out_tag,
    209                                             size_t *out_header_len);
    210 
    211 /* CBS_get_any_ber_asn1_element acts the same as |CBS_get_any_asn1_element| but
    212  * also allows indefinite-length elements to be returned. In that case,
    213  * |*out_header_len| and |CBS_len(out)| will both be two as only the header is
    214  * returned, otherwise it behaves the same as the previous function. */
    215 OPENSSL_EXPORT int CBS_get_any_ber_asn1_element(CBS *cbs, CBS *out,
    216                                                 unsigned *out_tag,
    217                                                 size_t *out_header_len);
    218 
    219 /* CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1|
    220  * and sets |*out| to its value. It returns one on success and zero on error,
    221  * where error includes the integer being negative, or too large to represent
    222  * in 64 bits. */
    223 OPENSSL_EXPORT int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out);
    224 
    225 /* CBS_get_optional_asn1 gets an optional explicitly-tagged element from |cbs|
    226  * tagged with |tag| and sets |*out| to its contents. If present and if
    227  * |out_present| is not NULL, it sets |*out_present| to one, otherwise zero. It
    228  * returns one on success, whether or not the element was present, and zero on
    229  * decode failure. */
    230 OPENSSL_EXPORT int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present,
    231                                          unsigned tag);
    232 
    233 /* CBS_get_optional_asn1_octet_string gets an optional
    234  * explicitly-tagged OCTET STRING from |cbs|. If present, it sets
    235  * |*out| to the string and |*out_present| to one. Otherwise, it sets
    236  * |*out| to empty and |*out_present| to zero. |out_present| may be
    237  * NULL. It returns one on success, whether or not the element was
    238  * present, and zero on decode failure. */
    239 OPENSSL_EXPORT int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out,
    240                                                       int *out_present,
    241                                                       unsigned tag);
    242 
    243 /* CBS_get_optional_asn1_uint64 gets an optional explicitly-tagged
    244  * INTEGER from |cbs|. If present, it sets |*out| to the
    245  * value. Otherwise, it sets |*out| to |default_value|. It returns one
    246  * on success, whether or not the element was present, and zero on
    247  * decode failure. */
    248 OPENSSL_EXPORT int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out,
    249                                                 unsigned tag,
    250                                                 uint64_t default_value);
    251 
    252 /* CBS_get_optional_asn1_bool gets an optional, explicitly-tagged BOOLEAN from
    253  * |cbs|. If present, it sets |*out| to either zero or one, based on the
    254  * boolean. Otherwise, it sets |*out| to |default_value|. It returns one on
    255  * success, whether or not the element was present, and zero on decode
    256  * failure. */
    257 OPENSSL_EXPORT int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned tag,
    258                                               int default_value);
    259 
    260 /* CBS_is_valid_asn1_bitstring returns one if |cbs| is a valid ASN.1 BIT STRING
    261  * and zero otherwise. */
    262 OPENSSL_EXPORT int CBS_is_valid_asn1_bitstring(const CBS *cbs);
    263 
    264 /* CBS_asn1_bitstring_has_bit returns one if |cbs| is a valid ASN.1 BIT STRING
    265  * and the specified bit is present and set. Otherwise, it returns zero. |bit|
    266  * is indexed starting from zero. */
    267 OPENSSL_EXPORT int CBS_asn1_bitstring_has_bit(const CBS *cbs, unsigned bit);
    268 
    269 
    270 /* CRYPTO ByteBuilder.
    271  *
    272  * |CBB| objects allow one to build length-prefixed serialisations. A |CBB|
    273  * object is associated with a buffer and new buffers are created with
    274  * |CBB_init|. Several |CBB| objects can point at the same buffer when a
    275  * length-prefix is pending, however only a single |CBB| can be 'current' at
    276  * any one time. For example, if one calls |CBB_add_u8_length_prefixed| then
    277  * the new |CBB| points at the same buffer as the original. But if the original
    278  * |CBB| is used then the length prefix is written out and the new |CBB| must
    279  * not be used again.
    280  *
    281  * If one needs to force a length prefix to be written out because a |CBB| is
    282  * going out of scope, use |CBB_flush|. If an operation on a |CBB| fails, it is
    283  * in an undefined state and must not be used except to call |CBB_cleanup|. */
    284 
    285 struct cbb_buffer_st {
    286   uint8_t *buf;
    287   size_t len;      /* The number of valid bytes. */
    288   size_t cap;      /* The size of buf. */
    289   char can_resize; /* One iff |buf| is owned by this object. If not then |buf|
    290                       cannot be resized. */
    291   char error;      /* One iff there was an error writing to this CBB. All future
    292                       operations will fail. */
    293 };
    294 
    295 struct cbb_st {
    296   struct cbb_buffer_st *base;
    297   /* child points to a child CBB if a length-prefix is pending. */
    298   CBB *child;
    299   /* offset is the number of bytes from the start of |base->buf| to this |CBB|'s
    300    * pending length prefix. */
    301   size_t offset;
    302   /* pending_len_len contains the number of bytes in this |CBB|'s pending
    303    * length-prefix, or zero if no length-prefix is pending. */
    304   uint8_t pending_len_len;
    305   char pending_is_asn1;
    306   /* is_top_level is true iff this is a top-level |CBB| (as opposed to a child
    307    * |CBB|). Top-level objects are valid arguments for |CBB_finish|. */
    308   char is_top_level;
    309 };
    310 
    311 /* CBB_zero sets an uninitialised |cbb| to the zero state. It must be
    312  * initialised with |CBB_init| or |CBB_init_fixed| before use, but it is safe to
    313  * call |CBB_cleanup| without a successful |CBB_init|. This may be used for more
    314  * uniform cleanup of a |CBB|. */
    315 OPENSSL_EXPORT void CBB_zero(CBB *cbb);
    316 
    317 /* CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as
    318  * needed, the |initial_capacity| is just a hint. It returns one on success or
    319  * zero on error. */
    320 OPENSSL_EXPORT int CBB_init(CBB *cbb, size_t initial_capacity);
    321 
    322 /* CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since
    323  * |buf| cannot grow, trying to write more than |len| bytes will cause CBB
    324  * functions to fail. It returns one on success or zero on error. */
    325 OPENSSL_EXPORT int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len);
    326 
    327 /* CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects
    328  * writing to the same buffer. This should be used in an error case where a
    329  * serialisation is abandoned.
    330  *
    331  * This function can only be called on a "top level" |CBB|, i.e. one initialised
    332  * with |CBB_init| or |CBB_init_fixed|, or a |CBB| set to the zero state with
    333  * |CBB_zero|. */
    334 OPENSSL_EXPORT void CBB_cleanup(CBB *cbb);
    335 
    336 /* CBB_finish completes any pending length prefix and sets |*out_data| to a
    337  * malloced buffer and |*out_len| to the length of that buffer. The caller
    338  * takes ownership of the buffer and, unless the buffer was fixed with
    339  * |CBB_init_fixed|, must call |OPENSSL_free| when done.
    340  *
    341  * It can only be called on a "top level" |CBB|, i.e. one initialised with
    342  * |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on
    343  * error. */
    344 OPENSSL_EXPORT int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len);
    345 
    346 /* CBB_flush causes any pending length prefixes to be written out and any child
    347  * |CBB| objects of |cbb| to be invalidated. This allows |cbb| to continue to be
    348  * used after the children go out of scope, e.g. when local |CBB| objects are
    349  * added as children to a |CBB| that persists after a function returns. This
    350  * function returns one on success or zero on error. */
    351 OPENSSL_EXPORT int CBB_flush(CBB *cbb);
    352 
    353 /* CBB_data returns a pointer to the bytes written to |cbb|. It does not flush
    354  * |cbb|. The pointer is valid until the next operation to |cbb|.
    355  *
    356  * To avoid unfinalized length prefixes, it is a fatal error to call this on a
    357  * CBB with any active children. */
    358 OPENSSL_EXPORT const uint8_t *CBB_data(const CBB *cbb);
    359 
    360 /* CBB_len returns the number of bytes written to |cbb|. It does not flush
    361  * |cbb|.
    362  *
    363  * To avoid unfinalized length prefixes, it is a fatal error to call this on a
    364  * CBB with any active children. */
    365 OPENSSL_EXPORT size_t CBB_len(const CBB *cbb);
    366 
    367 /* CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The
    368  * data written to |*out_contents| will be prefixed in |cbb| with an 8-bit
    369  * length. It returns one on success or zero on error. */
    370 OPENSSL_EXPORT int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents);
    371 
    372 /* CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|.
    373  * The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit,
    374  * big-endian length. It returns one on success or zero on error. */
    375 OPENSSL_EXPORT int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents);
    376 
    377 /* CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|.
    378  * The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit,
    379  * big-endian length. It returns one on success or zero on error. */
    380 OPENSSL_EXPORT int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents);
    381 
    382 /* CBB_add_asn1 sets |*out_contents| to a |CBB| into which the contents of an
    383  * ASN.1 object can be written. The |tag| argument will be used as the tag for
    384  * the object. Passing in |tag| number 31 will return in an error since only
    385  * single octet identifiers are supported. It returns one on success or zero
    386  * on error. */
    387 OPENSSL_EXPORT int CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned tag);
    388 
    389 /* CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on
    390  * success and zero otherwise. */
    391 OPENSSL_EXPORT int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len);
    392 
    393 /* CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to
    394  * the beginning of that space. The caller must then write |len| bytes of
    395  * actual contents to |*out_data|. It returns one on success and zero
    396  * otherwise. */
    397 OPENSSL_EXPORT int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len);
    398 
    399 /* CBB_reserve ensures |cbb| has room for |len| additional bytes and sets
    400  * |*out_data| to point to the beginning of that space. It returns one on
    401  * success and zero otherwise. The caller may write up to |len| bytes to
    402  * |*out_data| and call |CBB_did_write| to complete the write. |*out_data| is
    403  * valid until the next operation on |cbb| or an ancestor |CBB|. */
    404 OPENSSL_EXPORT int CBB_reserve(CBB *cbb, uint8_t **out_data, size_t len);
    405 
    406 /* CBB_did_write advances |cbb| by |len| bytes, assuming the space has been
    407  * written to by the caller. It returns one on success and zero on error. */
    408 OPENSSL_EXPORT int CBB_did_write(CBB *cbb, size_t len);
    409 
    410 /* CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on
    411  * success and zero otherwise. */
    412 OPENSSL_EXPORT int CBB_add_u8(CBB *cbb, uint8_t value);
    413 
    414 /* CBB_add_u16 appends a 16-bit, big-endian number from |value| to |cbb|. It
    415  * returns one on success and zero otherwise. */
    416 OPENSSL_EXPORT int CBB_add_u16(CBB *cbb, uint16_t value);
    417 
    418 /* CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It
    419  * returns one on success and zero otherwise. */
    420 OPENSSL_EXPORT int CBB_add_u24(CBB *cbb, uint32_t value);
    421 
    422 /* CBB_add_u32 appends a 32-bit, big-endian number from |value| to |cbb|. It
    423  * returns one on success and zero otherwise. */
    424 OPENSSL_EXPORT int CBB_add_u32(CBB *cbb, uint32_t value);
    425 
    426 /* CBB_discard_child discards the current unflushed child of |cbb|. Neither the
    427  * child's contents nor the length prefix will be included in the output. */
    428 OPENSSL_EXPORT void CBB_discard_child(CBB *cbb);
    429 
    430 /* CBB_add_asn1_uint64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1|
    431  * and writes |value| in its contents. It returns one on success and zero on
    432  * error. */
    433 OPENSSL_EXPORT int CBB_add_asn1_uint64(CBB *cbb, uint64_t value);
    434 
    435 
    436 #if defined(__cplusplus)
    437 }  /* extern C */
    438 
    439 
    440 #if !defined(BORINGSSL_NO_CXX)
    441 extern "C++" {
    442 
    443 namespace bssl {
    444 
    445 using ScopedCBB = internal::StackAllocated<CBB, void, CBB_zero, CBB_cleanup>;
    446 
    447 }  // namespace bssl
    448 
    449 }  // extern C++
    450 #endif
    451 
    452 #endif
    453 
    454 #endif  /* OPENSSL_HEADER_BYTESTRING_H */
    455