// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Cryptographic API.
   *
   * SHA-3, as specified in

   * https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf

   *
   * SHA-3 code by Jeff Garzik <jeff@garzik.org>

   *               Ard Biesheuvel <ard.biesheuvel@linaro.org>

   */
  #include <crypto/internal/hash.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <crypto/sha3.h>

  #include <asm/unaligned.h>

  /*

   * On some 32-bit architectures (h8300), GCC ends up using

   * over 1 KB of stack if we inline the round calculation into the loop
   * in keccakf(). On the other hand, on 64-bit architectures with plenty
   * of [64-bit wide] general purpose registers, not inlining it severely
   * hurts performance. So let's use 64-bitness as a heuristic to decide
   * whether to inline or not.
   */
  #ifdef CONFIG_64BIT
  #define SHA3_INLINE	inline
  #else
  #define SHA3_INLINE	noinline
  #endif

  #define KECCAK_ROUNDS 24

  static const u64 keccakf_rndc[24] = {

  	0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
  	0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
  	0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
  	0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
  	0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
  	0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
  	0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
  	0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL

  };

  /* update the state with given number of rounds */

  static SHA3_INLINE void keccakf_round(u64 st[25])

  {

  	u64 t[5], tt, bc[5];

  	/* Theta */
  	bc[0] = st[0] ^ st[5] ^ st[10] ^ st[15] ^ st[20];
  	bc[1] = st[1] ^ st[6] ^ st[11] ^ st[16] ^ st[21];
  	bc[2] = st[2] ^ st[7] ^ st[12] ^ st[17] ^ st[22];
  	bc[3] = st[3] ^ st[8] ^ st[13] ^ st[18] ^ st[23];
  	bc[4] = st[4] ^ st[9] ^ st[14] ^ st[19] ^ st[24];
  
  	t[0] = bc[4] ^ rol64(bc[1], 1);
  	t[1] = bc[0] ^ rol64(bc[2], 1);
  	t[2] = bc[1] ^ rol64(bc[3], 1);
  	t[3] = bc[2] ^ rol64(bc[4], 1);
  	t[4] = bc[3] ^ rol64(bc[0], 1);
  
  	st[0] ^= t[0];
  
  	/* Rho Pi */
  	tt = st[1];
  	st[ 1] = rol64(st[ 6] ^ t[1], 44);
  	st[ 6] = rol64(st[ 9] ^ t[4], 20);
  	st[ 9] = rol64(st[22] ^ t[2], 61);
  	st[22] = rol64(st[14] ^ t[4], 39);
  	st[14] = rol64(st[20] ^ t[0], 18);
  	st[20] = rol64(st[ 2] ^ t[2], 62);
  	st[ 2] = rol64(st[12] ^ t[2], 43);
  	st[12] = rol64(st[13] ^ t[3], 25);
  	st[13] = rol64(st[19] ^ t[4],  8);
  	st[19] = rol64(st[23] ^ t[3], 56);
  	st[23] = rol64(st[15] ^ t[0], 41);
  	st[15] = rol64(st[ 4] ^ t[4], 27);
  	st[ 4] = rol64(st[24] ^ t[4], 14);
  	st[24] = rol64(st[21] ^ t[1],  2);
  	st[21] = rol64(st[ 8] ^ t[3], 55);
  	st[ 8] = rol64(st[16] ^ t[1], 45);
  	st[16] = rol64(st[ 5] ^ t[0], 36);
  	st[ 5] = rol64(st[ 3] ^ t[3], 28);
  	st[ 3] = rol64(st[18] ^ t[3], 21);
  	st[18] = rol64(st[17] ^ t[2], 15);
  	st[17] = rol64(st[11] ^ t[1], 10);
  	st[11] = rol64(st[ 7] ^ t[2],  6);
  	st[ 7] = rol64(st[10] ^ t[0],  3);
  	st[10] = rol64(    tt ^ t[1],  1);
  
  	/* Chi */
  	bc[ 0] = ~st[ 1] & st[ 2];
  	bc[ 1] = ~st[ 2] & st[ 3];
  	bc[ 2] = ~st[ 3] & st[ 4];
  	bc[ 3] = ~st[ 4] & st[ 0];
  	bc[ 4] = ~st[ 0] & st[ 1];
  	st[ 0] ^= bc[ 0];
  	st[ 1] ^= bc[ 1];
  	st[ 2] ^= bc[ 2];
  	st[ 3] ^= bc[ 3];
  	st[ 4] ^= bc[ 4];
  
  	bc[ 0] = ~st[ 6] & st[ 7];
  	bc[ 1] = ~st[ 7] & st[ 8];
  	bc[ 2] = ~st[ 8] & st[ 9];
  	bc[ 3] = ~st[ 9] & st[ 5];
  	bc[ 4] = ~st[ 5] & st[ 6];
  	st[ 5] ^= bc[ 0];
  	st[ 6] ^= bc[ 1];
  	st[ 7] ^= bc[ 2];
  	st[ 8] ^= bc[ 3];
  	st[ 9] ^= bc[ 4];
  
  	bc[ 0] = ~st[11] & st[12];
  	bc[ 1] = ~st[12] & st[13];
  	bc[ 2] = ~st[13] & st[14];
  	bc[ 3] = ~st[14] & st[10];
  	bc[ 4] = ~st[10] & st[11];
  	st[10] ^= bc[ 0];
  	st[11] ^= bc[ 1];
  	st[12] ^= bc[ 2];
  	st[13] ^= bc[ 3];
  	st[14] ^= bc[ 4];
  
  	bc[ 0] = ~st[16] & st[17];
  	bc[ 1] = ~st[17] & st[18];
  	bc[ 2] = ~st[18] & st[19];
  	bc[ 3] = ~st[19] & st[15];
  	bc[ 4] = ~st[15] & st[16];
  	st[15] ^= bc[ 0];
  	st[16] ^= bc[ 1];
  	st[17] ^= bc[ 2];
  	st[18] ^= bc[ 3];
  	st[19] ^= bc[ 4];
  
  	bc[ 0] = ~st[21] & st[22];
  	bc[ 1] = ~st[22] & st[23];
  	bc[ 2] = ~st[23] & st[24];
  	bc[ 3] = ~st[24] & st[20];
  	bc[ 4] = ~st[20] & st[21];
  	st[20] ^= bc[ 0];
  	st[21] ^= bc[ 1];
  	st[22] ^= bc[ 2];
  	st[23] ^= bc[ 3];
  	st[24] ^= bc[ 4];
  }

  static void keccakf(u64 st[25])

  {
  	int round;

  	for (round = 0; round < KECCAK_ROUNDS; round++) {
  		keccakf_round(st);

  		/* Iota */
  		st[0] ^= keccakf_rndc[round];
  	}
  }

  int crypto_sha3_init(struct shash_desc *desc)

  {
  	struct sha3_state *sctx = shash_desc_ctx(desc);

  	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);

  	sctx->rsiz = 200 - 2 * digest_size;
  	sctx->rsizw = sctx->rsiz / 8;
  	sctx->partial = 0;

  	memset(sctx->st, 0, sizeof(sctx->st));

  	return 0;
  }

  EXPORT_SYMBOL(crypto_sha3_init);

  int crypto_sha3_update(struct shash_desc *desc, const u8 *data,

  		       unsigned int len)
  {
  	struct sha3_state *sctx = shash_desc_ctx(desc);
  	unsigned int done;
  	const u8 *src;
  
  	done = 0;
  	src = data;
  
  	if ((sctx->partial + len) > (sctx->rsiz - 1)) {
  		if (sctx->partial) {
  			done = -sctx->partial;
  			memcpy(sctx->buf + sctx->partial, data,
  			       done + sctx->rsiz);
  			src = sctx->buf;
  		}
  
  		do {
  			unsigned int i;
  
  			for (i = 0; i < sctx->rsizw; i++)

  				sctx->st[i] ^= get_unaligned_le64(src + 8 * i);

  			keccakf(sctx->st);
  
  			done += sctx->rsiz;
  			src = data + done;
  		} while (done + (sctx->rsiz - 1) < len);
  
  		sctx->partial = 0;
  	}
  	memcpy(sctx->buf + sctx->partial, src, len - done);
  	sctx->partial += (len - done);
  
  	return 0;
  }

  EXPORT_SYMBOL(crypto_sha3_update);

  int crypto_sha3_final(struct shash_desc *desc, u8 *out)

  {
  	struct sha3_state *sctx = shash_desc_ctx(desc);
  	unsigned int i, inlen = sctx->partial;

  	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
  	__le64 *digest = (__le64 *)out;

  
  	sctx->buf[inlen++] = 0x06;
  	memset(sctx->buf + inlen, 0, sctx->rsiz - inlen);
  	sctx->buf[sctx->rsiz - 1] |= 0x80;
  
  	for (i = 0; i < sctx->rsizw; i++)

  		sctx->st[i] ^= get_unaligned_le64(sctx->buf + 8 * i);

  
  	keccakf(sctx->st);

  	for (i = 0; i < digest_size / 8; i++)
  		put_unaligned_le64(sctx->st[i], digest++);

  	if (digest_size & 4)
  		put_unaligned_le32(sctx->st[i], (__le32 *)digest);

  
  	memset(sctx, 0, sizeof(*sctx));
  	return 0;
  }

  EXPORT_SYMBOL(crypto_sha3_final);

  static struct shash_alg algs[] = { {
  	.digestsize		= SHA3_224_DIGEST_SIZE,

  	.init			= crypto_sha3_init,
  	.update			= crypto_sha3_update,
  	.final			= crypto_sha3_final,

  	.descsize		= sizeof(struct sha3_state),
  	.base.cra_name		= "sha3-224",
  	.base.cra_driver_name	= "sha3-224-generic",

  	.base.cra_blocksize	= SHA3_224_BLOCK_SIZE,
  	.base.cra_module	= THIS_MODULE,
  }, {
  	.digestsize		= SHA3_256_DIGEST_SIZE,

  	.init			= crypto_sha3_init,
  	.update			= crypto_sha3_update,
  	.final			= crypto_sha3_final,

  	.descsize		= sizeof(struct sha3_state),
  	.base.cra_name		= "sha3-256",
  	.base.cra_driver_name	= "sha3-256-generic",

  	.base.cra_blocksize	= SHA3_256_BLOCK_SIZE,
  	.base.cra_module	= THIS_MODULE,
  }, {
  	.digestsize		= SHA3_384_DIGEST_SIZE,

  	.init			= crypto_sha3_init,
  	.update			= crypto_sha3_update,
  	.final			= crypto_sha3_final,

  	.descsize		= sizeof(struct sha3_state),
  	.base.cra_name		= "sha3-384",
  	.base.cra_driver_name	= "sha3-384-generic",

  	.base.cra_blocksize	= SHA3_384_BLOCK_SIZE,
  	.base.cra_module	= THIS_MODULE,
  }, {
  	.digestsize		= SHA3_512_DIGEST_SIZE,

  	.init			= crypto_sha3_init,
  	.update			= crypto_sha3_update,
  	.final			= crypto_sha3_final,

  	.descsize		= sizeof(struct sha3_state),
  	.base.cra_name		= "sha3-512",
  	.base.cra_driver_name	= "sha3-512-generic",

  	.base.cra_blocksize	= SHA3_512_BLOCK_SIZE,
  	.base.cra_module	= THIS_MODULE,
  } };

  
  static int __init sha3_generic_mod_init(void)
  {

  	return crypto_register_shashes(algs, ARRAY_SIZE(algs));

  }
  
  static void __exit sha3_generic_mod_fini(void)
  {

  	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));

  }

  subsys_initcall(sha3_generic_mod_init);

  module_exit(sha3_generic_mod_fini);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("SHA-3 Secure Hash Algorithm");
  
  MODULE_ALIAS_CRYPTO("sha3-224");
  MODULE_ALIAS_CRYPTO("sha3-224-generic");
  MODULE_ALIAS_CRYPTO("sha3-256");
  MODULE_ALIAS_CRYPTO("sha3-256-generic");
  MODULE_ALIAS_CRYPTO("sha3-384");
  MODULE_ALIAS_CRYPTO("sha3-384-generic");
  MODULE_ALIAS_CRYPTO("sha3-512");
  MODULE_ALIAS_CRYPTO("sha3-512-generic");