include/internal/sha3.h

/*
 * Copyright 2019-2026 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/* This header can move into provider when legacy support is removed */
#ifndef OSSL_INTERNAL_SHA3_H
#define OSSL_INTERNAL_SHA3_H
#pragma once

#include <openssl/e_os2.h>
#include <stddef.h>

#define KECCAK1600_WIDTH 1600
#define SHA3_MDSIZE(bitlen) (bitlen / 8)
#define CSHAKE_KECCAK_MDSIZE(bitlen) 2 * (bitlen / 8)
#define SHA3_BLOCKSIZE(bitlen) (KECCAK1600_WIDTH - bitlen * 2) / 8

typedef struct keccak_st KECCAK1600_CTX;

typedef size_t(sha3_absorb_fn)(KECCAK1600_CTX *vctx, const unsigned char *in, size_t inlen);
typedef int(sha3_final_fn)(KECCAK1600_CTX *vctx, unsigned char *out, size_t outlen);
typedef int(sha3_squeeze_fn)(KECCAK1600_CTX *vctx, unsigned char *out, size_t outlen);

typedef struct prov_sha3_meth_st {
    sha3_absorb_fn *absorb;
    sha3_final_fn *final;
    sha3_squeeze_fn *squeeze;
} PROV_SHA3_METHOD;

#define XOF_STATE_INIT 0
#define XOF_STATE_ABSORB 1
#define XOF_STATE_FINAL 2
#define XOF_STATE_SQUEEZE 3

struct keccak_st {
    uint64_t A[5][5];
    unsigned char buf[KECCAK1600_WIDTH / 8 - 32];
    size_t block_size; /* cached ctx->digest->block_size */
    size_t md_size; /* output length, variable in XOF */
    size_t bufsz; /* used bytes in below buffer */
    unsigned char pad;
    PROV_SHA3_METHOD meth;
    int xof_state;
};

KECCAK1600_CTX *ossl_shake256_new(void);
void ossl_sha3_reset(KECCAK1600_CTX *ctx);
int ossl_sha3_init(KECCAK1600_CTX *ctx, unsigned char pad, size_t bitlen);
int ossl_keccak_init(KECCAK1600_CTX *ctx, unsigned char pad,
    size_t typelen, size_t mdlen);

int ossl_sha3_absorb(KECCAK1600_CTX *ctx, const unsigned char *in, size_t len);
int ossl_sha3_final(KECCAK1600_CTX *ctx, unsigned char *out, size_t outlen);
int ossl_sha3_squeeze(KECCAK1600_CTX *ctx, unsigned char *out, size_t outlen);

size_t ossl_sha3_absorb_default(KECCAK1600_CTX *ctx, const unsigned char *inp, size_t len);
int ossl_sha3_final_default(KECCAK1600_CTX *ctx, unsigned char *out, size_t outlen);
int ossl_shake_squeeze_default(KECCAK1600_CTX *ctx, unsigned char *out, size_t outlen);

size_t SHA3_absorb(uint64_t A[5][5], const unsigned char *inp, size_t len,
    size_t r);

#endif /* OSSL_INTERNAL_SHA3_H */