// 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_SHA_H
#define OPENSSL_HEADER_SHA_H

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

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


// The SHA family of hash functions (SHA-1 and SHA-2).


// SHA-1.

// SHA_CBLOCK is the block size of SHA-1.
#define SHA_CBLOCK 64

// SHA_DIGEST_LENGTH is the length of a SHA-1 digest.
#define SHA_DIGEST_LENGTH 20

// SHA1_Init initialises |sha| and returns one.
OPENSSL_EXPORT int SHA1_Init(SHA_CTX *sha);

// SHA1_Update adds |len| bytes from |data| to |sha| and returns one.
OPENSSL_EXPORT int SHA1_Update(SHA_CTX *sha, const void *data, size_t len);

// SHA1_Final adds the final padding to |sha| and writes the resulting digest to
// |out|, which must have at least |SHA_DIGEST_LENGTH| bytes of space. It
// returns one.
OPENSSL_EXPORT int SHA1_Final(uint8_t out[SHA_DIGEST_LENGTH], SHA_CTX *sha);

// SHA1 writes the digest of |len| bytes from |data| to |out| and returns
// |out|. There must be at least |SHA_DIGEST_LENGTH| bytes of space in
// |out|.
OPENSSL_EXPORT uint8_t *SHA1(const uint8_t *data, size_t len,
                             uint8_t out[SHA_DIGEST_LENGTH]);

// SHA1_Transform is a low-level function that performs a single, SHA-1 block
// transformation using the state from |sha| and |SHA_CBLOCK| bytes from
// |block|.
OPENSSL_EXPORT void SHA1_Transform(SHA_CTX *sha,
                                   const uint8_t block[SHA_CBLOCK]);

// CRYPTO_fips_186_2_prf derives |out_len| bytes from |xkey| using the PRF
// defined in FIPS 186-2, Appendix 3.1, with change notice 1 applied. The b
// parameter is 160 and seed, XKEY, is also 160 bits. The optional XSEED user
// input is all zeros.
//
// The PRF generates a sequence of 320-bit numbers. Each number is encoded as a
// 40-byte string in big-endian and then concatenated to form |out|. If
// |out_len| is not a multiple of 40, the result is truncated. This matches the
// construction used in Section 7 of RFC 4186 and Section 7 of RFC 4187.
//
// This PRF is based on SHA-1, a weak hash function, and should not be used
// in new protocols. It is provided for compatibility with some legacy EAP
// methods.
OPENSSL_EXPORT void CRYPTO_fips_186_2_prf(
    uint8_t *out, size_t out_len, const uint8_t xkey[SHA_DIGEST_LENGTH]);


// 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);


// 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]);


// 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_SHA_H