zfs/module/os/freebsd/spl/sha256c.c - backupdr - Git at Google

 /*
  * Copyright 2005 Colin Percival
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");

 #include <sys/types.h>

 #ifdef _KERNEL
 #include <sys/systm.h>
 #else
 #include <string.h>
 #endif


 #include <sys/byteorder.h>
 #include <sys/endian.h>
 #include "sha224.h"
 #include "sha256.h"

 #if BYTE_ORDER == BIG_ENDIAN

 /* Copy a vector of big-endian uint32_t into a vector of bytes */
 #define	be32enc_vect(dst, src, len)	\
 	memcpy((void *)dst, (const void *)src, (size_t)len)

 /* Copy a vector of bytes into a vector of big-endian uint32_t */
 #define	be32dec_vect(dst, src, len)	\
 	memcpy((void *)dst, (const void *)src, (size_t)len)

 #else /* BYTE_ORDER != BIG_ENDIAN */

 /*
  * Encode a length len/4 vector of (uint32_t) into a length len vector of
  * (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
  */
 static void
 be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
 {
 	size_t i;

 	for (i = 0; i < len / 4; i++)
 		be32enc(dst + i * 4, src[i]);
 }

 /*
  * Decode a big-endian length len vector of (unsigned char) into a length
  * len/4 vector of (uint32_t).  Assumes len is a multiple of 4.
  */
 static void
 be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
 {
 	size_t i;

 	for (i = 0; i < len / 4; i++)
 		dst[i] = be32dec(src + i * 4);
 }

 #endif /* BYTE_ORDER != BIG_ENDIAN */

 /* SHA256 round constants. */
 static const uint32_t K[64] = {
 	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
 	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
 	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
 	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
 	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
 	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
 	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
 	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
 	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
 	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
 	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
 	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
 	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
 	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
 	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
 	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };

 /* Elementary functions used by SHA256 */
 #define	Ch(x, y, z)	((x & (y ^ z)) ^ z)
 #define	Maj(x, y, z)	((x & (y | z)) | (y & z))
 #define	SHR(x, n)	(x >> n)
 #define	ROTR(x, n)	((x >> n) | (x << (32 - n)))
 #define	S0(x)		(ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
 #define	S1(x)		(ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
 #define	s0(x)		(ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
 #define	s1(x)		(ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))

 /* SHA256 round function */
 #define	RND(a, b, c, d, e, f, g, h, k)			\
 	h += S1(e) + Ch(e, f, g) + k;			\
 	d += h;						\
 	h += S0(a) + Maj(a, b, c);

 /* Adjusted round function for rotating state */
 #define	RNDr(S, W, i, ii)			\
 	RND(S[(64 - i) % 8], S[(65 - i) % 8],	\
 	    S[(66 - i) % 8], S[(67 - i) % 8],	\
 	    S[(68 - i) % 8], S[(69 - i) % 8],	\
 	    S[(70 - i) % 8], S[(71 - i) % 8],	\
 	    W[i + ii] + K[i + ii])

 /* Message schedule computation */
 #define	MSCH(W, ii, i)				\
 	W[i + ii + 16] = s1(W[i + ii + 14]) + W[i + ii + 9] +	\
 		s0(W[i + ii + 1]) + W[i + ii]

 /*
  * SHA256 block compression function.  The 256-bit state is transformed via
  * the 512-bit input block to produce a new state.
  */
 static void
 SHA256_Transform(uint32_t *state, const unsigned char block[64])
 {
 	uint32_t W[64];
 	uint32_t S[8];
 	int i;

 	/* 1. Prepare the first part of the message schedule W. */
 	be32dec_vect(W, block, 64);

 	/* 2. Initialize working variables. */
 	memcpy(S, state, 32);

 	/* 3. Mix. */
 	for (i = 0; i < 64; i += 16) {
 		RNDr(S, W, 0, i);
 		RNDr(S, W, 1, i);
 		RNDr(S, W, 2, i);
 		RNDr(S, W, 3, i);
 		RNDr(S, W, 4, i);
 		RNDr(S, W, 5, i);
 		RNDr(S, W, 6, i);
 		RNDr(S, W, 7, i);
 		RNDr(S, W, 8, i);
 		RNDr(S, W, 9, i);
 		RNDr(S, W, 10, i);
 		RNDr(S, W, 11, i);
 		RNDr(S, W, 12, i);
 		RNDr(S, W, 13, i);
 		RNDr(S, W, 14, i);
 		RNDr(S, W, 15, i);

 		if (i == 48)
 			break;
 		MSCH(W, 0, i);
 		MSCH(W, 1, i);
 		MSCH(W, 2, i);
 		MSCH(W, 3, i);
 		MSCH(W, 4, i);
 		MSCH(W, 5, i);
 		MSCH(W, 6, i);
 		MSCH(W, 7, i);
 		MSCH(W, 8, i);
 		MSCH(W, 9, i);
 		MSCH(W, 10, i);
 		MSCH(W, 11, i);
 		MSCH(W, 12, i);
 		MSCH(W, 13, i);
 		MSCH(W, 14, i);
 		MSCH(W, 15, i);
 	}

 	/* 4. Mix local working variables into global state */
 	for (i = 0; i < 8; i++)
 		state[i] += S[i];
 }

 static unsigned char PAD[64] = {
 	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 };

 /* Add padding and terminating bit-count. */
 static void
 SHA256_Pad(SHA256_CTX * ctx)
 {
 	size_t r;

 	/* Figure out how many bytes we have buffered. */
 	r = (ctx->count >> 3) & 0x3f;

 	/* Pad to 56 mod 64, transforming if we finish a block en route. */
 	if (r < 56) {
 		/* Pad to 56 mod 64. */
 		memcpy(&ctx->buf[r], PAD, 56 - r);
 	} else {
 		/* Finish the current block and mix. */
 		memcpy(&ctx->buf[r], PAD, 64 - r);
 		SHA256_Transform(ctx->state, ctx->buf);

 		/* The start of the final block is all zeroes. */
 		memset(&ctx->buf[0], 0, 56);
 	}

 	/* Add the terminating bit-count. */
 	be64enc(&ctx->buf[56], ctx->count);

 	/* Mix in the final block. */
 	SHA256_Transform(ctx->state, ctx->buf);
 }

 /* SHA-256 initialization.  Begins a SHA-256 operation. */
 void
 SHA256_Init(SHA256_CTX * ctx)
 {

 	/* Zero bits processed so far */
 	ctx->count = 0;

 	/* Magic initialization constants */
 	ctx->state[0] = 0x6A09E667;
 	ctx->state[1] = 0xBB67AE85;
 	ctx->state[2] = 0x3C6EF372;
 	ctx->state[3] = 0xA54FF53A;
 	ctx->state[4] = 0x510E527F;
 	ctx->state[5] = 0x9B05688C;
 	ctx->state[6] = 0x1F83D9AB;
 	ctx->state[7] = 0x5BE0CD19;
 }

 /* Add bytes into the hash */
 void
 SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len)
 {
 	uint64_t bitlen;
 	uint32_t r;
 	const unsigned char *src = in;

 	/* Number of bytes left in the buffer from previous updates */
 	r = (ctx->count >> 3) & 0x3f;

 	/* Convert the length into a number of bits */
 	bitlen = len << 3;

 	/* Update number of bits */
 	ctx->count += bitlen;

 	/* Handle the case where we don't need to perform any transforms */
 	if (len < 64 - r) {
 		memcpy(&ctx->buf[r], src, len);
 		return;
 	}

 	/* Finish the current block */
 	memcpy(&ctx->buf[r], src, 64 - r);
 	SHA256_Transform(ctx->state, ctx->buf);
 	src += 64 - r;
 	len -= 64 - r;

 	/* Perform complete blocks */
 	while (len >= 64) {
 		SHA256_Transform(ctx->state, src);
 		src += 64;
 		len -= 64;
 	}

 	/* Copy left over data into buffer */
 	memcpy(ctx->buf, src, len);
 }

 /*
  * SHA-256 finalization.  Pads the input data, exports the hash value,
  * and clears the context state.
  */
 void
 SHA256_Final(unsigned char digest[static SHA256_DIGEST_LENGTH], SHA256_CTX *ctx)
 {

 	/* Add padding */
 	SHA256_Pad(ctx);

 	/* Write the hash */
 	be32enc_vect(digest, ctx->state, SHA256_DIGEST_LENGTH);

 	/* Clear the context state */
 	explicit_bzero(ctx, sizeof (*ctx));
 }

 /* SHA-224: ******************************************************* */
 /*
  * the SHA224 and SHA256 transforms are identical
  */

 /* SHA-224 initialization.  Begins a SHA-224 operation. */
 void
 SHA224_Init(SHA224_CTX * ctx)
 {

 	/* Zero bits processed so far */
 	ctx->count = 0;

 	/* Magic initialization constants */
 	ctx->state[0] = 0xC1059ED8;
 	ctx->state[1] = 0x367CD507;
 	ctx->state[2] = 0x3070DD17;
 	ctx->state[3] = 0xF70E5939;
 	ctx->state[4] = 0xFFC00B31;
 	ctx->state[5] = 0x68581511;
 	ctx->state[6] = 0x64f98FA7;
 	ctx->state[7] = 0xBEFA4FA4;
 }

 /* Add bytes into the SHA-224 hash */
 void
 SHA224_Update(SHA224_CTX * ctx, const void *in, size_t len)
 {

 	SHA256_Update((SHA256_CTX *)ctx, in, len);
 }

 /*
  * SHA-224 finalization.  Pads the input data, exports the hash value,
  * and clears the context state.
  */
 void
 SHA224_Final(unsigned char digest[static SHA224_DIGEST_LENGTH], SHA224_CTX *ctx)
 {

 	/* Add padding */
 	SHA256_Pad((SHA256_CTX *)ctx);

 	/* Write the hash */
 	be32enc_vect(digest, ctx->state, SHA224_DIGEST_LENGTH);

 	/* Clear the context state */
 	explicit_bzero(ctx, sizeof (*ctx));
 }

 #ifdef WEAK_REFS
 /*
  * When building libmd, provide weak references. Note: this is not
  * activated in the context of compiling these sources for internal
  * use in libcrypt.
  */
 #undef SHA256_Init
 __weak_reference(_libmd_SHA256_Init, SHA256_Init);
 #undef SHA256_Update
 __weak_reference(_libmd_SHA256_Update, SHA256_Update);
 #undef SHA256_Final
 __weak_reference(_libmd_SHA256_Final, SHA256_Final);
 #undef SHA256_Transform
 __weak_reference(_libmd_SHA256_Transform, SHA256_Transform);

 #undef SHA224_Init
 __weak_reference(_libmd_SHA224_Init, SHA224_Init);
 #undef SHA224_Update
 __weak_reference(_libmd_SHA224_Update, SHA224_Update);
 #undef SHA224_Final
 __weak_reference(_libmd_SHA224_Final, SHA224_Final);
 #endif
	/*
	* Copyright 2005 Colin Percival
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	#include <sys/cdefs.h>
	__FBSDID("$FreeBSD$");

	#include <sys/types.h>

	#ifdef _KERNEL
	#include <sys/systm.h>
	#else
	#include <string.h>
	#endif


	#include <sys/byteorder.h>
	#include <sys/endian.h>
	#include "sha224.h"
	#include "sha256.h"

	#if BYTE_ORDER == BIG_ENDIAN

	/* Copy a vector of big-endian uint32_t into a vector of bytes */
	#define be32enc_vect(dst, src, len) \
	memcpy((void )dst, (const void )src, (size_t)len)

	/* Copy a vector of bytes into a vector of big-endian uint32_t */
	#define be32dec_vect(dst, src, len) \
	memcpy((void )dst, (const void )src, (size_t)len)

	#else /* BYTE_ORDER != BIG_ENDIAN */

	/*
	* Encode a length len/4 vector of (uint32_t) into a length len vector of
	* (unsigned char) in big-endian form. Assumes len is a multiple of 4.
	*/
	static void
	be32enc_vect(unsigned char dst, const uint32_t src, size_t len)
	{
	size_t i;

	for (i = 0; i < len / 4; i++)
	be32enc(dst + i * 4, src[i]);
	}

	/*
	* Decode a big-endian length len vector of (unsigned char) into a length
	* len/4 vector of (uint32_t). Assumes len is a multiple of 4.
	*/
	static void
	be32dec_vect(uint32_t dst, const unsigned char src, size_t len)
	{
	size_t i;

	for (i = 0; i < len / 4; i++)
	dst[i] = be32dec(src + i * 4);
	}

	#endif /* BYTE_ORDER != BIG_ENDIAN */

	/* SHA256 round constants. */
	static const uint32_t K[64] = {
	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
	};

	/* Elementary functions used by SHA256 */
	#define Ch(x, y, z) ((x & (y ^ z)) ^ z)
	#define Maj(x, y, z) ((x & (y \| z)) \| (y & z))
	#define SHR(x, n) (x >> n)
	#define ROTR(x, n) ((x >> n) \| (x << (32 - n)))
	#define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
	#define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
	#define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
	#define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))

	/* SHA256 round function */
	#define RND(a, b, c, d, e, f, g, h, k) \
	h += S1(e) + Ch(e, f, g) + k; \
	d += h; \
	h += S0(a) + Maj(a, b, c);

	/* Adjusted round function for rotating state */
	#define RNDr(S, W, i, ii) \
	RND(S[(64 - i) % 8], S[(65 - i) % 8], \
	S[(66 - i) % 8], S[(67 - i) % 8], \
	S[(68 - i) % 8], S[(69 - i) % 8], \
	S[(70 - i) % 8], S[(71 - i) % 8], \
	W[i + ii] + K[i + ii])

	/* Message schedule computation */
	#define MSCH(W, ii, i) \
	W[i + ii + 16] = s1(W[i + ii + 14]) + W[i + ii + 9] + \
	s0(W[i + ii + 1]) + W[i + ii]

	/*
	* SHA256 block compression function. The 256-bit state is transformed via
	* the 512-bit input block to produce a new state.
	*/
	static void
	SHA256_Transform(uint32_t *state, const unsigned char block[64])
	{
	uint32_t W[64];
	uint32_t S[8];
	int i;

	/* 1. Prepare the first part of the message schedule W. */
	be32dec_vect(W, block, 64);

	/* 2. Initialize working variables. */
	memcpy(S, state, 32);

	/* 3. Mix. */
	for (i = 0; i < 64; i += 16) {
	RNDr(S, W, 0, i);
	RNDr(S, W, 1, i);
	RNDr(S, W, 2, i);
	RNDr(S, W, 3, i);
	RNDr(S, W, 4, i);
	RNDr(S, W, 5, i);
	RNDr(S, W, 6, i);
	RNDr(S, W, 7, i);
	RNDr(S, W, 8, i);
	RNDr(S, W, 9, i);
	RNDr(S, W, 10, i);
	RNDr(S, W, 11, i);
	RNDr(S, W, 12, i);
	RNDr(S, W, 13, i);
	RNDr(S, W, 14, i);
	RNDr(S, W, 15, i);

	if (i == 48)
	break;
	MSCH(W, 0, i);
	MSCH(W, 1, i);
	MSCH(W, 2, i);
	MSCH(W, 3, i);
	MSCH(W, 4, i);
	MSCH(W, 5, i);
	MSCH(W, 6, i);
	MSCH(W, 7, i);
	MSCH(W, 8, i);
	MSCH(W, 9, i);
	MSCH(W, 10, i);
	MSCH(W, 11, i);
	MSCH(W, 12, i);
	MSCH(W, 13, i);
	MSCH(W, 14, i);
	MSCH(W, 15, i);
	}

	/* 4. Mix local working variables into global state */
	for (i = 0; i < 8; i++)
	state[i] += S[i];
	}

	static unsigned char PAD[64] = {
	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};

	/* Add padding and terminating bit-count. */
	static void
	SHA256_Pad(SHA256_CTX * ctx)
	{
	size_t r;

	/* Figure out how many bytes we have buffered. */
	r = (ctx->count >> 3) & 0x3f;

	/* Pad to 56 mod 64, transforming if we finish a block en route. */
	if (r < 56) {
	/* Pad to 56 mod 64. */
	memcpy(&ctx->buf[r], PAD, 56 - r);
	} else {
	/* Finish the current block and mix. */
	memcpy(&ctx->buf[r], PAD, 64 - r);
	SHA256_Transform(ctx->state, ctx->buf);

	/* The start of the final block is all zeroes. */
	memset(&ctx->buf[0], 0, 56);
	}

	/* Add the terminating bit-count. */
	be64enc(&ctx->buf[56], ctx->count);

	/* Mix in the final block. */
	SHA256_Transform(ctx->state, ctx->buf);
	}

	/* SHA-256 initialization. Begins a SHA-256 operation. */
	void
	SHA256_Init(SHA256_CTX * ctx)
	{

	/* Zero bits processed so far */
	ctx->count = 0;

	/* Magic initialization constants */
	ctx->state[0] = 0x6A09E667;
	ctx->state[1] = 0xBB67AE85;
	ctx->state[2] = 0x3C6EF372;
	ctx->state[3] = 0xA54FF53A;
	ctx->state[4] = 0x510E527F;
	ctx->state[5] = 0x9B05688C;
	ctx->state[6] = 0x1F83D9AB;
	ctx->state[7] = 0x5BE0CD19;
	}

	/* Add bytes into the hash */
	void
	SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len)
	{
	uint64_t bitlen;
	uint32_t r;
	const unsigned char *src = in;

	/* Number of bytes left in the buffer from previous updates */
	r = (ctx->count >> 3) & 0x3f;

	/* Convert the length into a number of bits */
	bitlen = len << 3;

	/* Update number of bits */
	ctx->count += bitlen;

	/* Handle the case where we don't need to perform any transforms */
	if (len < 64 - r) {
	memcpy(&ctx->buf[r], src, len);
	return;
	}

	/* Finish the current block */
	memcpy(&ctx->buf[r], src, 64 - r);
	SHA256_Transform(ctx->state, ctx->buf);
	src += 64 - r;
	len -= 64 - r;

	/* Perform complete blocks */
	while (len >= 64) {
	SHA256_Transform(ctx->state, src);
	src += 64;
	len -= 64;
	}

	/* Copy left over data into buffer */
	memcpy(ctx->buf, src, len);
	}

	/*
	* SHA-256 finalization. Pads the input data, exports the hash value,
	* and clears the context state.
	*/
	void
	SHA256_Final(unsigned char digest[static SHA256_DIGEST_LENGTH], SHA256_CTX *ctx)
	{

	/* Add padding */
	SHA256_Pad(ctx);

	/* Write the hash */
	be32enc_vect(digest, ctx->state, SHA256_DIGEST_LENGTH);

	/* Clear the context state */
	explicit_bzero(ctx, sizeof (*ctx));
	}

	/* SHA-224: ******************************************************* */
	/*
	* the SHA224 and SHA256 transforms are identical
	*/

	/* SHA-224 initialization. Begins a SHA-224 operation. */
	void
	SHA224_Init(SHA224_CTX * ctx)
	{

	/* Zero bits processed so far */
	ctx->count = 0;

	/* Magic initialization constants */
	ctx->state[0] = 0xC1059ED8;
	ctx->state[1] = 0x367CD507;
	ctx->state[2] = 0x3070DD17;
	ctx->state[3] = 0xF70E5939;
	ctx->state[4] = 0xFFC00B31;
	ctx->state[5] = 0x68581511;
	ctx->state[6] = 0x64f98FA7;
	ctx->state[7] = 0xBEFA4FA4;
	}

	/* Add bytes into the SHA-224 hash */
	void
	SHA224_Update(SHA224_CTX * ctx, const void *in, size_t len)
	{

	SHA256_Update((SHA256_CTX *)ctx, in, len);
	}

	/*
	* SHA-224 finalization. Pads the input data, exports the hash value,
	* and clears the context state.
	*/
	void
	SHA224_Final(unsigned char digest[static SHA224_DIGEST_LENGTH], SHA224_CTX *ctx)
	{

	/* Add padding */
	SHA256_Pad((SHA256_CTX *)ctx);

	/* Write the hash */
	be32enc_vect(digest, ctx->state, SHA224_DIGEST_LENGTH);

	/* Clear the context state */
	explicit_bzero(ctx, sizeof (*ctx));
	}

	#ifdef WEAK_REFS
	/*
	* When building libmd, provide weak references. Note: this is not
	* activated in the context of compiling these sources for internal
	* use in libcrypt.
	*/
	#undef SHA256_Init
	__weak_reference(_libmd_SHA256_Init, SHA256_Init);
	#undef SHA256_Update
	__weak_reference(_libmd_SHA256_Update, SHA256_Update);
	#undef SHA256_Final
	__weak_reference(_libmd_SHA256_Final, SHA256_Final);
	#undef SHA256_Transform
	__weak_reference(_libmd_SHA256_Transform, SHA256_Transform);

	#undef SHA224_Init
	__weak_reference(_libmd_SHA224_Init, SHA224_Init);
	#undef SHA224_Update
	__weak_reference(_libmd_SHA224_Update, SHA224_Update);
	#undef SHA224_Final
	__weak_reference(_libmd_SHA224_Final, SHA224_Final);
	#endif