| /* Copyright (c) 2014, Google Inc. |
| * |
| * Permission to use, copy, modify, and/or distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| |
| #ifndef OPENSSL_HEADER_BYTESTRING_H |
| #define OPENSSL_HEADER_BYTESTRING_H |
| |
| #include <openssl/base.h> |
| |
| #if defined(__cplusplus) |
| extern "C" { |
| #endif |
| |
| |
| /* Bytestrings are used for parsing and building TLS and ASN.1 messages. |
| * |
| * A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and |
| * provides utility functions for safely parsing length-prefixed structures |
| * like TLS and ASN.1 from it. |
| * |
| * A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and |
| * provides utility functions for building length-prefixed messages. */ |
| |
| |
| /* CRYPTO ByteString */ |
| |
| struct cbs_st { |
| const uint8_t *data; |
| size_t len; |
| }; |
| |
| /* CBS_init sets |cbs| to point to |data|. It does not take ownership of |
| * |data|. */ |
| OPENSSL_EXPORT void CBS_init(CBS *cbs, const uint8_t *data, size_t len); |
| |
| /* CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero |
| * otherwise. */ |
| OPENSSL_EXPORT int CBS_skip(CBS *cbs, size_t len); |
| |
| /* CBS_data returns a pointer to the contains of |cbs|. */ |
| OPENSSL_EXPORT const uint8_t *CBS_data(const CBS *cbs); |
| |
| /* CBS_len returns the number of bytes remaining in |cbs|. */ |
| OPENSSL_EXPORT size_t CBS_len(const CBS *cbs); |
| |
| /* CBS_stow copies the current contents of |cbs| into |*out_ptr| and |
| * |*out_len|. If |*out_ptr| is not NULL, the contents are freed with |
| * OPENSSL_free. It returns one on success and zero on allocation failure. On |
| * success, |*out_ptr| should be freed with OPENSSL_free. If |cbs| is empty, |
| * |*out_ptr| will be NULL. */ |
| OPENSSL_EXPORT int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len); |
| |
| /* CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a |
| * NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed |
| * with OPENSSL_free. It returns one on success and zero on allocation |
| * failure. On success, |*out_ptr| should be freed with OPENSSL_free. |
| * |
| * NOTE: If |cbs| contains NUL bytes, the string will be truncated. Call |
| * |CBS_contains_zero_byte(cbs)| to check for NUL bytes. */ |
| OPENSSL_EXPORT int CBS_strdup(const CBS *cbs, char **out_ptr); |
| |
| /* CBS_contains_zero_byte returns one if the current contents of |cbs| contains |
| * a NUL byte and zero otherwise. */ |
| OPENSSL_EXPORT int CBS_contains_zero_byte(const CBS *cbs); |
| |
| /* CBS_mem_equal compares the current contents of |cbs| with the |len| bytes |
| * starting at |data|. If they're equal, it returns one, otherwise zero. If the |
| * lengths match, it uses a constant-time comparison. */ |
| OPENSSL_EXPORT int CBS_mem_equal(const CBS *cbs, const uint8_t *data, |
| size_t len); |
| |
| /* CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It |
| * returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u8(CBS *cbs, uint8_t *out); |
| |
| /* CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and |
| * advances |cbs|. It returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u16(CBS *cbs, uint16_t *out); |
| |
| /* CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and |
| * advances |cbs|. It returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u24(CBS *cbs, uint32_t *out); |
| |
| /* CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs| |
| * and advances |cbs|. It returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u32(CBS *cbs, uint32_t *out); |
| |
| /* CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances |
| * |cbs|. It returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_bytes(CBS *cbs, CBS *out, size_t len); |
| |
| /* CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit, |
| * length-prefixed value from |cbs| and advances |cbs| over it. It returns one |
| * on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out); |
| |
| /* CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit, |
| * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It |
| * returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out); |
| |
| /* CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit, |
| * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It |
| * returns one on success and zero on error. */ |
| OPENSSL_EXPORT int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out); |
| |
| |
| /* Parsing ASN.1 */ |
| |
| #define CBS_ASN1_BOOLEAN 0x1 |
| #define CBS_ASN1_INTEGER 0x2 |
| #define CBS_ASN1_BITSTRING 0x3 |
| #define CBS_ASN1_OCTETSTRING 0x4 |
| #define CBS_ASN1_OBJECT 0x6 |
| #define CBS_ASN1_ENUMERATED 0xa |
| #define CBS_ASN1_SEQUENCE (0x10 | CBS_ASN1_CONSTRUCTED) |
| #define CBS_ASN1_SET (0x11 | CBS_ASN1_CONSTRUCTED) |
| |
| #define CBS_ASN1_CONSTRUCTED 0x20 |
| #define CBS_ASN1_CONTEXT_SPECIFIC 0x80 |
| |
| /* CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not |
| * including tag and length bytes) and advances |cbs| over it. The ASN.1 |
| * element must match |tag_value|. It returns one on success and zero |
| * on error. |
| * |
| * Tag numbers greater than 31 are not supported. */ |
| OPENSSL_EXPORT int CBS_get_asn1(CBS *cbs, CBS *out, unsigned tag_value); |
| |
| /* CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the |
| * ASN.1 header bytes too. */ |
| OPENSSL_EXPORT int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value); |
| |
| /* CBS_peek_asn1_tag looks ahead at the next ASN.1 tag and returns one |
| * if the next ASN.1 element on |cbs| would have tag |tag_value|. If |
| * |cbs| is empty or the tag does not match, it returns zero. Note: if |
| * it returns one, CBS_get_asn1 may still fail if the rest of the |
| * element is malformed. */ |
| OPENSSL_EXPORT int CBS_peek_asn1_tag(const CBS *cbs, unsigned tag_value); |
| |
| /* CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from |
| * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to |
| * the tag number and |*out_header_len| to the length of the ASN.1 header. If |
| * the element has indefinite length then |*out| will only contain the |
| * header. Each of |out|, |out_tag|, and |out_header_len| may be NULL to ignore |
| * the value. |
| * |
| * Tag numbers greater than 31 are not supported. */ |
| OPENSSL_EXPORT int CBS_get_any_asn1_element(CBS *cbs, CBS *out, |
| unsigned *out_tag, |
| size_t *out_header_len); |
| |
| /* CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1| |
| * and sets |*out| to its value. It returns one on success and zero on error, |
| * where error includes the integer being negative, or too large to represent |
| * in 64 bits. */ |
| OPENSSL_EXPORT int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out); |
| |
| /* CBS_get_optional_asn1 gets an optional explicitly-tagged element |
| * from |cbs| tagged with |tag| and sets |*out| to its contents. If |
| * present, it sets |*out_present| to one, otherwise zero. It returns |
| * one on success, whether or not the element was present, and zero on |
| * decode failure. */ |
| OPENSSL_EXPORT int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, |
| unsigned tag); |
| |
| /* CBS_get_optional_asn1_octet_string gets an optional |
| * explicitly-tagged OCTET STRING from |cbs|. If present, it sets |
| * |*out| to the string and |*out_present| to one. Otherwise, it sets |
| * |*out| to empty and |*out_present| to zero. |out_present| may be |
| * NULL. It returns one on success, whether or not the element was |
| * present, and zero on decode failure. */ |
| OPENSSL_EXPORT int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, |
| int *out_present, |
| unsigned tag); |
| |
| /* CBS_get_optional_asn1_uint64 gets an optional explicitly-tagged |
| * INTEGER from |cbs|. If present, it sets |*out| to the |
| * value. Otherwise, it sets |*out| to |default_value|. It returns one |
| * on success, whether or not the element was present, and zero on |
| * decode failure. */ |
| OPENSSL_EXPORT int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, |
| unsigned tag, |
| uint64_t default_value); |
| |
| /* CBS_get_optional_asn1_bool gets an optional, explicitly-tagged BOOLEAN from |
| * |cbs|. If present, it sets |*out| to either zero or one, based on the |
| * boolean. Otherwise, it sets |*out| to |default_value|. It returns one on |
| * success, whether or not the element was present, and zero on decode |
| * failure. */ |
| OPENSSL_EXPORT int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned tag, |
| int default_value); |
| |
| |
| /* CRYPTO ByteBuilder. |
| * |
| * |CBB| objects allow one to build length-prefixed serialisations. A |CBB| |
| * object is associated with a buffer and new buffers are created with |
| * |CBB_init|. Several |CBB| objects can point at the same buffer when a |
| * length-prefix is pending, however only a single |CBB| can be 'current' at |
| * any one time. For example, if one calls |CBB_add_u8_length_prefixed| then |
| * the new |CBB| points at the same buffer as the original. But if the original |
| * |CBB| is used then the length prefix is written out and the new |CBB| must |
| * not be used again. |
| * |
| * If one needs to force a length prefix to be written out because a |CBB| is |
| * going out of scope, use |CBB_flush|. */ |
| |
| struct cbb_buffer_st { |
| uint8_t *buf; |
| size_t len; /* The number of valid bytes. */ |
| size_t cap; /* The size of buf. */ |
| char can_resize; /* One iff |buf| is owned by this object. If not then |buf| |
| cannot be resized. */ |
| }; |
| |
| struct cbb_st { |
| struct cbb_buffer_st *base; |
| /* offset is the offset from the start of |base->buf| to the position of any |
| * pending length-prefix. */ |
| size_t offset; |
| /* child points to a child CBB if a length-prefix is pending. */ |
| struct cbb_st *child; |
| /* pending_len_len contains the number of bytes in a pending length-prefix, |
| * or zero if no length-prefix is pending. */ |
| uint8_t pending_len_len; |
| char pending_is_asn1; |
| /* is_top_level is true iff this is a top-level |CBB| (as opposed to a child |
| * |CBB|). Top-level objects are valid arguments for |CBB_finish|. */ |
| char is_top_level; |
| }; |
| |
| /* CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as |
| * needed, the |initial_capacity| is just a hint. It returns one on success or |
| * zero on error. */ |
| OPENSSL_EXPORT int CBB_init(CBB *cbb, size_t initial_capacity); |
| |
| /* CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since |
| * |buf| cannot grow, trying to write more than |len| bytes will cause CBB |
| * functions to fail. It returns one on success or zero on error. */ |
| OPENSSL_EXPORT int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len); |
| |
| /* CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects |
| * writing to the same buffer. This should be used in an error case where a |
| * serialisation is abandoned. */ |
| OPENSSL_EXPORT void CBB_cleanup(CBB *cbb); |
| |
| /* CBB_finish completes any pending length prefix and sets |*out_data| to a |
| * malloced buffer and |*out_len| to the length of that buffer. The caller |
| * takes ownership of the buffer and, unless the buffer was fixed with |
| * |CBB_init_fixed|, must call |OPENSSL_free| when done. |
| * |
| * It can only be called on a "top level" |CBB|, i.e. one initialised with |
| * |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on |
| * error. */ |
| OPENSSL_EXPORT int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len); |
| |
| /* CBB_flush causes any pending length prefixes to be written out and any child |
| * |CBB| objects of |cbb| to be invalidated. It returns one on success or zero |
| * on error. */ |
| OPENSSL_EXPORT int CBB_flush(CBB *cbb); |
| |
| /* CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The |
| * data written to |*out_contents| will be prefixed in |cbb| with an 8-bit |
| * length. It returns one on success or zero on error. */ |
| OPENSSL_EXPORT int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents); |
| |
| /* CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|. |
| * The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit, |
| * big-endian length. It returns one on success or zero on error. */ |
| OPENSSL_EXPORT int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents); |
| |
| /* CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|. |
| * The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit, |
| * big-endian length. It returns one on success or zero on error. */ |
| OPENSSL_EXPORT int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents); |
| |
| /* CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an |
| * ASN.1 object can be written. The |tag| argument will be used as the tag for |
| * the object. It returns one on success or zero on error. */ |
| OPENSSL_EXPORT int CBB_add_asn1(CBB *cbb, CBB *out_contents, uint8_t tag); |
| |
| /* CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on |
| * success and zero otherwise. */ |
| OPENSSL_EXPORT int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len); |
| |
| /* CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to |
| * the beginning of that space. The caller must then write |len| bytes of |
| * actual contents to |*out_data|. It returns one on success and zero |
| * otherwise. */ |
| OPENSSL_EXPORT int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len); |
| |
| /* CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on |
| * success and zero otherwise. */ |
| OPENSSL_EXPORT int CBB_add_u8(CBB *cbb, uint8_t value); |
| |
| /* CBB_add_u8 appends a 16-bit, big-endian number from |value| to |cbb|. It |
| * returns one on success and zero otherwise. */ |
| OPENSSL_EXPORT int CBB_add_u16(CBB *cbb, uint16_t value); |
| |
| /* CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It |
| * returns one on success and zero otherwise. */ |
| OPENSSL_EXPORT int CBB_add_u24(CBB *cbb, uint32_t value); |
| |
| /* CBB_add_asn1_uint64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1| |
| * and writes |value| in its contents. It returns one on success and zero on |
| * error. */ |
| OPENSSL_EXPORT int CBB_add_asn1_uint64(CBB *cbb, uint64_t value); |
| |
| #if defined(__cplusplus) |
| } /* extern C */ |
| #endif |
| |
| #endif /* OPENSSL_HEADER_BYTESTRING_H */ |