include/openssl/sha2.h

// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef OPENSSL_HEADER_SHA2_H
#define OPENSSL_HEADER_SHA2_H

#include <openssl/base.h>  // IWYU pragma: export

#if defined(__cplusplus)
extern "C" {
#endif


// The SHA-2 family of hash functions.


// SHA-224.

// SHA224_CBLOCK is the block size of SHA-224.
#define SHA224_CBLOCK 64

// SHA224_DIGEST_LENGTH is the length of a SHA-224 digest.
#define SHA224_DIGEST_LENGTH 28

// SHA224_Init initialises `sha` and returns 1.
OPENSSL_EXPORT int SHA224_Init(SHA256_CTX *sha);

// SHA224_Update adds `len` bytes from `data` to `sha` and returns 1.
OPENSSL_EXPORT int SHA224_Update(SHA256_CTX *sha, const void *data, size_t len);

// SHA224_Final adds the final padding to `sha` and writes the resulting digest
// to `out`, which must have at least `SHA224_DIGEST_LENGTH` bytes of space. It
// returns 1.
OPENSSL_EXPORT int SHA224_Final(uint8_t out[SHA224_DIGEST_LENGTH],
                                SHA256_CTX *sha);

// SHA224 writes the digest of `len` bytes from `data` to `out` and returns
// `out`. There must be at least `SHA224_DIGEST_LENGTH` bytes of space in
// `out`.
OPENSSL_EXPORT uint8_t *SHA224(const uint8_t *data, size_t len,
                               uint8_t out[SHA224_DIGEST_LENGTH]);


// SHA-256.

// SHA256_CBLOCK is the block size of SHA-256.
#define SHA256_CBLOCK 64

// SHA256_DIGEST_LENGTH is the length of a SHA-256 digest.
#define SHA256_DIGEST_LENGTH 32

// SHA256_Init initialises `sha` and returns 1.
OPENSSL_EXPORT int SHA256_Init(SHA256_CTX *sha);

// SHA256_Update adds `len` bytes from `data` to `sha` and returns 1.
OPENSSL_EXPORT int SHA256_Update(SHA256_CTX *sha, const void *data, size_t len);

// SHA256_Final adds the final padding to `sha` and writes the resulting digest
// to `out`, which must have at least `SHA256_DIGEST_LENGTH` bytes of space. It
// returns one on success and zero on programmer error.
OPENSSL_EXPORT int SHA256_Final(uint8_t out[SHA256_DIGEST_LENGTH],
                                SHA256_CTX *sha);

// SHA256 writes the digest of `len` bytes from `data` to `out` and returns
// `out`. There must be at least `SHA256_DIGEST_LENGTH` bytes of space in
// `out`.
OPENSSL_EXPORT uint8_t *SHA256(const uint8_t *data, size_t len,
                               uint8_t out[SHA256_DIGEST_LENGTH]);

// SHA256_Transform is a low-level function that performs a single, SHA-256
// block transformation using the state from `sha` and `SHA256_CBLOCK` bytes
// from `block`.
OPENSSL_EXPORT void SHA256_Transform(SHA256_CTX *sha,
                                     const uint8_t block[SHA256_CBLOCK]);

// SHA256_TransformBlocks is a low-level function that takes `num_blocks` *
// `SHA256_CBLOCK` bytes of data and performs SHA-256 transforms on it to update
// `state`. You should not use this function unless you are implementing a
// derivative of SHA-256.
OPENSSL_EXPORT void SHA256_TransformBlocks(uint32_t state[8],
                                           const uint8_t *data,
                                           size_t num_blocks);

struct sha256_state_st {
  uint32_t h[8];
  uint32_t Nl, Nh;
  uint8_t data[SHA256_CBLOCK];
  unsigned num, md_len;
} /* SHA256_CTX */;


// SHA-384.

// SHA384_CBLOCK is the block size of SHA-384.
#define SHA384_CBLOCK 128

// SHA384_DIGEST_LENGTH is the length of a SHA-384 digest.
#define SHA384_DIGEST_LENGTH 48

// SHA384_Init initialises `sha` and returns 1.
OPENSSL_EXPORT int SHA384_Init(SHA512_CTX *sha);

// SHA384_Update adds `len` bytes from `data` to `sha` and returns 1.
OPENSSL_EXPORT int SHA384_Update(SHA512_CTX *sha, const void *data, size_t len);

// SHA384_Final adds the final padding to `sha` and writes the resulting digest
// to `out`, which must have at least `SHA384_DIGEST_LENGTH` bytes of space. It
// returns one on success and zero on programmer error.
OPENSSL_EXPORT int SHA384_Final(uint8_t out[SHA384_DIGEST_LENGTH],
                                SHA512_CTX *sha);

// SHA384 writes the digest of `len` bytes from `data` to `out` and returns
// `out`. There must be at least `SHA384_DIGEST_LENGTH` bytes of space in
// `out`.
OPENSSL_EXPORT uint8_t *SHA384(const uint8_t *data, size_t len,
                               uint8_t out[SHA384_DIGEST_LENGTH]);


// SHA-512.

// SHA512_CBLOCK is the block size of SHA-512.
#define SHA512_CBLOCK 128

// SHA512_DIGEST_LENGTH is the length of a SHA-512 digest.
#define SHA512_DIGEST_LENGTH 64

// SHA512_Init initialises `sha` and returns 1.
OPENSSL_EXPORT int SHA512_Init(SHA512_CTX *sha);

// SHA512_Update adds `len` bytes from `data` to `sha` and returns 1.
OPENSSL_EXPORT int SHA512_Update(SHA512_CTX *sha, const void *data, size_t len);

// SHA512_Final adds the final padding to `sha` and writes the resulting digest
// to `out`, which must have at least `SHA512_DIGEST_LENGTH` bytes of space. It
// returns one on success and zero on programmer error.
OPENSSL_EXPORT int SHA512_Final(uint8_t out[SHA512_DIGEST_LENGTH],
                                SHA512_CTX *sha);

// SHA512 writes the digest of `len` bytes from `data` to `out` and returns
// `out`. There must be at least `SHA512_DIGEST_LENGTH` bytes of space in
// `out`.
OPENSSL_EXPORT uint8_t *SHA512(const uint8_t *data, size_t len,
                               uint8_t out[SHA512_DIGEST_LENGTH]);

// SHA512_Transform is a low-level function that performs a single, SHA-512
// block transformation using the state from `sha` and `SHA512_CBLOCK` bytes
// from `block`.
OPENSSL_EXPORT void SHA512_Transform(SHA512_CTX *sha,
                                     const uint8_t block[SHA512_CBLOCK]);

struct sha512_state_st {
  uint64_t h[8];
  uint16_t num, md_len;
  uint32_t bytes_so_far_high;
  uint64_t bytes_so_far_low;
  uint8_t p[SHA512_CBLOCK];
} /* SHA512_CTX */;


// SHA-512-256
//
// See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf section 5.3.6

#define SHA512_256_DIGEST_LENGTH 32

// SHA512_256_Init initialises `sha` and returns 1.
OPENSSL_EXPORT int SHA512_256_Init(SHA512_CTX *sha);

// SHA512_256_Update adds `len` bytes from `data` to `sha` and returns 1.
OPENSSL_EXPORT int SHA512_256_Update(SHA512_CTX *sha, const void *data,
                                     size_t len);

// SHA512_256_Final adds the final padding to `sha` and writes the resulting
// digest to `out`, which must have at least `SHA512_256_DIGEST_LENGTH` bytes of
// space. It returns one on success and zero on programmer error.
OPENSSL_EXPORT int SHA512_256_Final(uint8_t out[SHA512_256_DIGEST_LENGTH],
                                    SHA512_CTX *sha);

// SHA512_256 writes the digest of `len` bytes from `data` to `out` and returns
// `out`. There must be at least `SHA512_256_DIGEST_LENGTH` bytes of space in
// `out`.
OPENSSL_EXPORT uint8_t *SHA512_256(const uint8_t *data, size_t len,
                                   uint8_t out[SHA512_256_DIGEST_LENGTH]);


#if defined(__cplusplus)
}  // extern C
#endif

#endif  // OPENSSL_HEADER_SHA2_H