eeb9f491e8
This function serialises a PKCS#7 structure containing a number of certificates. Change-Id: Iaf15887e1060d5d201d5a3dd3dca8d51105ee6d6 Reviewed-on: https://boringssl-review.googlesource.com/1431 Reviewed-by: Adam Langley <agl@google.com>
272 lines
12 KiB
C
272 lines
12 KiB
C
/* Copyright (c) 2014, Google Inc.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
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* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
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#ifndef OPENSSL_HEADER_BYTESTRING_H
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#define OPENSSL_HEADER_BYTESTRING_H
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#include <openssl/base.h>
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#if defined(__cplusplus)
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extern "C" {
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#endif
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/* Bytestrings are used for parsing and building TLS and ASN.1 messages.
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*
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* A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and
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* provides utility functions for safely parsing length-prefixed structures
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* like TLS and ASN.1 from it.
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*
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* A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and
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* provides utility functions for building length-prefixed messages. */
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/* CRYPTO ByteString */
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struct cbs_st {
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const uint8_t *data;
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size_t len;
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};
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/* CBS_init sets |cbs| to point to |data|. It does not take ownership of
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* |data|. */
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OPENSSL_EXPORT void CBS_init(CBS *cbs, const uint8_t *data, size_t len);
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/* CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero
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* otherwise. */
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OPENSSL_EXPORT int CBS_skip(CBS *cbs, size_t len);
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/* CBS_data returns a pointer to the contains of |cbs|. */
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OPENSSL_EXPORT const uint8_t *CBS_data(const CBS *cbs);
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/* CBS_len returns the number of bytes remaining in |cbs|. */
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OPENSSL_EXPORT size_t CBS_len(const CBS *cbs);
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/* CBS_stow copies the current contents of |cbs| into |*out_ptr| and
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* |*out_len|. If |*out_ptr| is not NULL, the contents are freed with
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* OPENSSL_free. It returns one on success and zero on allocation failure. On
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* success, |*out_ptr| should be freed with OPENSSL_free. If |cbs| is empty,
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* |*out_ptr| will be NULL. */
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OPENSSL_EXPORT int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len);
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/* CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a
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* NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed
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* with OPENSSL_free. It returns one on success and zero on allocation
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* failure. On success, |*out_ptr| should be freed with OPENSSL_free.
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*
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* NOTE: If |cbs| contains NUL bytes, the string will be truncated. Call
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* |CBS_contains_zero_byte(cbs)| to check for NUL bytes. */
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OPENSSL_EXPORT int CBS_strdup(const CBS *cbs, char **out_ptr);
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/* CBS_contains_zero_byte returns one if the current contents of |cbs| contains
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* a NUL byte and zero otherwise. */
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OPENSSL_EXPORT int CBS_contains_zero_byte(const CBS *cbs);
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/* CBS_mem_equal compares the current contents of |cbs| with the |len| bytes
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* starting at |data|. If they're equal, it returns one, otherwise zero. If the
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* lengths match, it uses a constant-time comparison. */
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OPENSSL_EXPORT int CBS_mem_equal(const CBS *cbs, const uint8_t *data,
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size_t len);
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/* CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It
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* returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u8(CBS *cbs, uint8_t *out);
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/* CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and
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* advances |cbs|. It returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u16(CBS *cbs, uint16_t *out);
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/* CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and
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* advances |cbs|. It returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u24(CBS *cbs, uint32_t *out);
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/* CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs|
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* and advances |cbs|. It returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u32(CBS *cbs, uint32_t *out);
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/* CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances
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* |cbs|. It returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_bytes(CBS *cbs, CBS *out, size_t len);
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/* CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit,
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* length-prefixed value from |cbs| and advances |cbs| over it. It returns one
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* on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out);
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/* CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit,
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* big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It
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* returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out);
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/* CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit,
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* big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It
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* returns one on success and zero on error. */
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OPENSSL_EXPORT int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out);
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/* Parsing ASN.1 */
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#define CBS_ASN1_BOOLEAN 0x1
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#define CBS_ASN1_INTEGER 0x2
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#define CBS_ASN1_BITSTRING 0x3
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#define CBS_ASN1_OCTETSTRING 0x4
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#define CBS_ASN1_OBJECT 0x6
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#define CBS_ASN1_SEQUENCE (0x10 | CBS_ASN1_CONSTRUCTED)
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#define CBS_ASN1_SET (0x11 | CBS_ASN1_CONSTRUCTED)
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#define CBS_ASN1_CONSTRUCTED 0x20
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#define CBS_ASN1_CONTEXT_SPECIFIC 0x80
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#define CBS_ASN1_ANY 0x10000
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/* CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not
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* including tag and length bytes) and advances |cbs| over it. The ASN.1
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* element must match |tag_value|. It returns one on success and zero
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* on error.
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*
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* Tag numbers greater than 31 are not supported. */
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OPENSSL_EXPORT int CBS_get_asn1(CBS *cbs, CBS *out, unsigned tag_value);
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/* CBS_get_asn1_ber sets |*out| to the contents of BER-encoded, ASN.1 element
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* (not including tag and length bytes) and advances |cbs| over it. The ASN.1
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* element must match |tag_value|. It returns one on success and zero on error.
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*
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* The major difference between this function and |CBS_get_asn1| is that
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* indefinite-length elements may be processed by this function.
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*
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* Tag numbers greater than 31 are not supported. */
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OPENSSL_EXPORT int CBS_get_asn1_ber(CBS *cbs, CBS *out, unsigned tag_value);
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/* CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the
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* ASN.1 header bytes too. */
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OPENSSL_EXPORT int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value);
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/* CRYPTO ByteBuilder.
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*
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* |CBB| objects allow one to build length-prefixed serialisations. A |CBB|
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* object is associated with a buffer and new buffers are created with
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* |CBB_init|. Several |CBB| objects can point at the same buffer when a
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* length-prefix is pending, however only a single |CBB| can be 'current' at
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* any one time. For example, if one calls |CBB_add_u8_length_prefixed| then
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* the new |CBB| points at the same buffer as the original. But if the original
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* |CBB| is used then the length prefix is written out and the new |CBB| must
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* not be used again.
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*
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* If one needs to force a length prefix to be written out because a |CBB| is
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* going out of scope, use |CBB_flush|. */
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struct cbb_buffer_st {
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uint8_t *buf;
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size_t len; /* The number of valid bytes. */
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size_t cap; /* The size of buf. */
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char can_resize; /* One iff |buf| is owned by this object. If not then |buf|
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cannot be resized. */
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};
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struct cbb_st {
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struct cbb_buffer_st *base;
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/* offset is the offset from the start of |base->buf| to the position of any
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* pending length-prefix. */
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size_t offset;
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/* child points to a child CBB if a length-prefix is pending. */
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struct cbb_st *child;
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/* pending_len_len contains the number of bytes in a pending length-prefix,
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* or zero if no length-prefix is pending. */
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uint8_t pending_len_len;
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char pending_is_asn1;
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/* is_top_level is true iff this is a top-level |CBB| (as opposed to a child
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* |CBB|). Top-level objects are valid arguments for |CBB_finish|. */
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char is_top_level;
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};
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/* CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as
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* needed, the |initial_capacity| is just a hint. It returns one on success or
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* zero on error. */
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OPENSSL_EXPORT int CBB_init(CBB *cbb, size_t initial_capacity);
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/* CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since
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* |buf| cannot grow, trying to write more than |len| bytes will cause CBB
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* functions to fail. It returns one on success or zero on error. */
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OPENSSL_EXPORT int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len);
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/* CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects
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* writing to the same buffer. This should be used in an error case where a
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* serialisation is abandoned. */
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OPENSSL_EXPORT void CBB_cleanup(CBB *cbb);
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/* CBB_finish completes any pending length prefix and sets |*out_data| to a
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* malloced buffer and |*out_len| to the length of that buffer. The caller
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* takes ownership of the buffer and, unless the buffer was fixed with
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* |CBB_init_fixed|, must call |OPENSSL_free| when done.
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*
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* It can only be called on a "top level" |CBB|, i.e. one initialised with
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* |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on
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* error. */
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OPENSSL_EXPORT int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len);
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/* CBB_flush causes any pending length prefixes to be written out and any child
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* |CBB| objects of |cbb| to be invalidated. It returns one on success or zero
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* on error. */
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OPENSSL_EXPORT int CBB_flush(CBB *cbb);
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/* CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The
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* data written to |*out_contents| will be prefixed in |cbb| with an 8-bit
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* length. It returns one on success or zero on error. */
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OPENSSL_EXPORT int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents);
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/* CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|.
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* The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit,
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* big-endian length. It returns one on success or zero on error. */
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OPENSSL_EXPORT int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents);
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/* CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|.
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* The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit,
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* big-endian length. It returns one on success or zero on error. */
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OPENSSL_EXPORT int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents);
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/* CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an
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* ASN.1 object can be written. The |tag| argument will be used as the tag for
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* the object. It returns one on success or zero on error. */
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OPENSSL_EXPORT int CBB_add_asn1(CBB *cbb, CBB *out_contents, uint8_t tag);
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/* CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on
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* success and zero otherwise. */
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OPENSSL_EXPORT int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len);
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/* CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to
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* the beginning of that space. The caller must then write |len| bytes of
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* actual contents to |*out_data|. It returns one on success and zero
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* otherwise. */
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OPENSSL_EXPORT int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len);
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/* CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on
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* success and zero otherwise. */
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OPENSSL_EXPORT int CBB_add_u8(CBB *cbb, uint8_t value);
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/* CBB_add_u8 appends a 16-bit, big-endian number from |value| to |cbb|. It
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* returns one on success and zero otherwise. */
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OPENSSL_EXPORT int CBB_add_u16(CBB *cbb, uint16_t value);
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/* CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It
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* returns one on success and zero otherwise. */
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OPENSSL_EXPORT int CBB_add_u24(CBB *cbb, uint32_t value);
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#if defined(__cplusplus)
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} /* extern C */
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#endif
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#endif /* OPENSSL_HEADER_BYTESTRING_H */
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