src/crypto/sha512.c - ipxe - Git at Google

 /*
  * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
  *
  * You can also choose to distribute this program under the terms of
  * the Unmodified Binary Distribution Licence (as given in the file
  * COPYING.UBDL), provided that you have satisfied its requirements.
  */

 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

 /** @file
  *
  * SHA-512 algorithm
  *
  */

 #include <stdint.h>
 #include <string.h>
 #include <byteswap.h>
 #include <assert.h>
 #include <ipxe/rotate.h>
 #include <ipxe/crypto.h>
 #include <ipxe/sha512.h>

 /** SHA-512 variables */
 struct sha512_variables {
 	/* This layout matches that of struct sha512_digest_data,
 	 * allowing for efficient endianness-conversion,
 	 */
 	uint64_t a;
 	uint64_t b;
 	uint64_t c;
 	uint64_t d;
 	uint64_t e;
 	uint64_t f;
 	uint64_t g;
 	uint64_t h;
 	uint64_t w[SHA512_ROUNDS];
 } __attribute__ (( packed ));

 /** SHA-512 constants */
 static const uint64_t k[SHA512_ROUNDS] = {
 	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
 	0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
 	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
 	0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
 	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
 	0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
 	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
 	0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
 	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
 	0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
 	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
 	0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
 	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
 	0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
 	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
 	0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
 	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
 	0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
 	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
 	0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
 	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
 	0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
 	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
 	0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
 	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
 	0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
 	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
 };

 /** SHA-512 initial digest values */
 static const struct sha512_digest sha512_init_digest = {
 	.h = {
 		cpu_to_be64 ( 0x6a09e667f3bcc908ULL ),
 		cpu_to_be64 ( 0xbb67ae8584caa73bULL ),
 		cpu_to_be64 ( 0x3c6ef372fe94f82bULL ),
 		cpu_to_be64 ( 0xa54ff53a5f1d36f1ULL ),
 		cpu_to_be64 ( 0x510e527fade682d1ULL ),
 		cpu_to_be64 ( 0x9b05688c2b3e6c1fULL ),
 		cpu_to_be64 ( 0x1f83d9abfb41bd6bULL ),
 		cpu_to_be64 ( 0x5be0cd19137e2179ULL ),
 	},
 };

 /**
  * Initialise SHA-512 family algorithm
  *
  * @v context		SHA-512 context
  * @v init		Initial digest values
  * @v digestsize	Digest size
  */
 void sha512_family_init ( struct sha512_context *context,
 			  const struct sha512_digest *init,
 			  size_t digestsize ) {

 	context->len = 0;
 	context->digestsize = digestsize;
 	memcpy ( &context->ddq.dd.digest, init,
 		 sizeof ( context->ddq.dd.digest ) );
 }

 /**
  * Initialise SHA-512 algorithm
  *
  * @v ctx		SHA-512 context
  */
 static void sha512_init ( void *ctx ) {
 	struct sha512_context *context = ctx;

 	sha512_family_init ( context, &sha512_init_digest,
 			     sizeof ( struct sha512_digest ) );
 }

 /**
  * Calculate SHA-512 digest of accumulated data
  *
  * @v context		SHA-512 context
  */
 static void sha512_digest ( struct sha512_context *context ) {
         union {
 		union sha512_digest_data_qwords ddq;
 		struct sha512_variables v;
 	} u;
 	uint64_t *a = &u.v.a;
 	uint64_t *b = &u.v.b;
 	uint64_t *c = &u.v.c;
 	uint64_t *d = &u.v.d;
 	uint64_t *e = &u.v.e;
 	uint64_t *f = &u.v.f;
 	uint64_t *g = &u.v.g;
 	uint64_t *h = &u.v.h;
 	uint64_t *w = u.v.w;
 	uint64_t s0;
 	uint64_t s1;
 	uint64_t maj;
 	uint64_t t1;
 	uint64_t t2;
 	uint64_t ch;
 	unsigned int i;

 	/* Sanity checks */
 	assert ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 );
 	build_assert ( &u.ddq.dd.digest.h[0] == a );
 	build_assert ( &u.ddq.dd.digest.h[1] == b );
 	build_assert ( &u.ddq.dd.digest.h[2] == c );
 	build_assert ( &u.ddq.dd.digest.h[3] == d );
 	build_assert ( &u.ddq.dd.digest.h[4] == e );
 	build_assert ( &u.ddq.dd.digest.h[5] == f );
 	build_assert ( &u.ddq.dd.digest.h[6] == g );
 	build_assert ( &u.ddq.dd.digest.h[7] == h );
 	build_assert ( &u.ddq.dd.data.qword[0] == w );

 	DBGC ( context, "SHA512 digesting:\n" );
 	DBGC_HDA ( context, 0, &context->ddq.dd.digest,
 		   sizeof ( context->ddq.dd.digest ) );
 	DBGC_HDA ( context, context->len, &context->ddq.dd.data,
 		   sizeof ( context->ddq.dd.data ) );

 	/* Convert h[0..7] to host-endian, and initialise a, b, c, d,
 	 * e, f, g, h, and w[0..15]
 	 */
 	for ( i = 0 ; i < ( sizeof ( u.ddq.qword ) /
 			    sizeof ( u.ddq.qword[0] ) ) ; i++ ) {
 		be64_to_cpus ( &context->ddq.qword[i] );
 		u.ddq.qword[i] = context->ddq.qword[i];
 	}

 	/* Initialise w[16..79] */
 	for ( i = 16 ; i < SHA512_ROUNDS ; i++ ) {
 		s0 = ( ror64 ( w[i-15], 1 ) ^ ror64 ( w[i-15], 8 ) ^
 		       ( w[i-15] >> 7 ) );
 		s1 = ( ror64 ( w[i-2], 19 ) ^ ror64 ( w[i-2], 61 ) ^
 		       ( w[i-2] >> 6 ) );
 		w[i] = ( w[i-16] + s0 + w[i-7] + s1 );
 	}

 	/* Main loop */
 	for ( i = 0 ; i < SHA512_ROUNDS ; i++ ) {
 		s0 = ( ror64 ( *a, 28 ) ^ ror64 ( *a, 34 ) ^ ror64 ( *a, 39 ) );
 		maj = ( ( *a & *b ) ^ ( *a & *c ) ^ ( *b & *c ) );
 		t2 = ( s0 + maj );
 		s1 = ( ror64 ( *e, 14 ) ^ ror64 ( *e, 18 ) ^ ror64 ( *e, 41 ) );
 		ch = ( ( *e & *f ) ^ ( (~*e) & *g ) );
 		t1 = ( *h + s1 + ch + k[i] + w[i] );
 		*h = *g;
 		*g = *f;
 		*f = *e;
 		*e = ( *d + t1 );
 		*d = *c;
 		*c = *b;
 		*b = *a;
 		*a = ( t1 + t2 );
 		DBGC2 ( context, "%2d : %016llx %016llx %016llx %016llx "
 			"%016llx %016llx %016llx %016llx\n",
 			i, *a, *b, *c, *d, *e, *f, *g, *h );
 	}

 	/* Add chunk to hash and convert back to big-endian */
 	for ( i = 0 ; i < 8 ; i++ ) {
 		context->ddq.dd.digest.h[i] =
 			cpu_to_be64 ( context->ddq.dd.digest.h[i] +
 				      u.ddq.dd.digest.h[i] );
 	}

 	DBGC ( context, "SHA512 digested:\n" );
 	DBGC_HDA ( context, 0, &context->ddq.dd.digest,
 		   sizeof ( context->ddq.dd.digest ) );
 }

 /**
  * Accumulate data with SHA-512 algorithm
  *
  * @v ctx		SHA-512 context
  * @v data		Data
  * @v len		Length of data
  */
 void sha512_update ( void *ctx, const void *data, size_t len ) {
 	struct sha512_context *context = ctx;
 	const uint8_t *byte = data;
 	size_t offset;

 	/* Accumulate data a byte at a time, performing the digest
 	 * whenever we fill the data buffer
 	 */
 	while ( len-- ) {
 		offset = ( context->len % sizeof ( context->ddq.dd.data ) );
 		context->ddq.dd.data.byte[offset] = *(byte++);
 		context->len++;
 		if ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 )
 			sha512_digest ( context );
 	}
 }

 /**
  * Generate SHA-512 digest
  *
  * @v ctx		SHA-512 context
  * @v out		Output buffer
  */
 void sha512_final ( void *ctx, void *out ) {
 	struct sha512_context *context = ctx;
 	uint64_t len_bits_hi;
 	uint64_t len_bits_lo;
 	uint8_t pad;

 	/* Record length before pre-processing */
 	len_bits_hi = 0;
 	len_bits_lo = cpu_to_be64 ( ( ( uint64_t ) context->len ) * 8 );

 	/* Pad with a single "1" bit followed by as many "0" bits as required */
 	pad = 0x80;
 	do {
 		sha512_update ( ctx, &pad, sizeof ( pad ) );
 		pad = 0x00;
 	} while ( ( context->len % sizeof ( context->ddq.dd.data ) ) !=
 		  offsetof ( typeof ( context->ddq.dd.data ), final.len_hi ) );

 	/* Append length (in bits) */
 	sha512_update ( ctx, &len_bits_hi, sizeof ( len_bits_hi ) );
 	sha512_update ( ctx, &len_bits_lo, sizeof ( len_bits_lo ) );
 	assert ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 );

 	/* Copy out final digest */
 	memcpy ( out, &context->ddq.dd.digest, context->digestsize );
 }

 /** SHA-512 algorithm */
 struct digest_algorithm sha512_algorithm = {
 	.name		= "sha512",
 	.ctxsize	= sizeof ( struct sha512_context ),
 	.blocksize	= sizeof ( union sha512_block ),
 	.digestsize	= sizeof ( struct sha512_digest ),
 	.init		= sha512_init,
 	.update		= sha512_update,
 	.final		= sha512_final,
 };
	/*
	* Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of the
	* License, or any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	* 02110-1301, USA.
	*
	* You can also choose to distribute this program under the terms of
	* the Unmodified Binary Distribution Licence (as given in the file
	* COPYING.UBDL), provided that you have satisfied its requirements.
	*/

	FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

	/** @file
	*
	* SHA-512 algorithm
	*
	*/

	#include <stdint.h>
	#include <string.h>
	#include <byteswap.h>
	#include <assert.h>
	#include <ipxe/rotate.h>
	#include <ipxe/crypto.h>
	#include <ipxe/sha512.h>

	/** SHA-512 variables */
	struct sha512_variables {
	/* This layout matches that of struct sha512_digest_data,
	* allowing for efficient endianness-conversion,
	*/
	uint64_t a;
	uint64_t b;
	uint64_t c;
	uint64_t d;
	uint64_t e;
	uint64_t f;
	uint64_t g;
	uint64_t h;
	uint64_t w[SHA512_ROUNDS];
	} __attribute__ (( packed ));

	/** SHA-512 constants */
	static const uint64_t k[SHA512_ROUNDS] = {
	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
	0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
	0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
	0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
	0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
	0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
	0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
	0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
	0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
	0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
	0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
	0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
	0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
	0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
	};

	/** SHA-512 initial digest values */
	static const struct sha512_digest sha512_init_digest = {
	.h = {
	cpu_to_be64 ( 0x6a09e667f3bcc908ULL ),
	cpu_to_be64 ( 0xbb67ae8584caa73bULL ),
	cpu_to_be64 ( 0x3c6ef372fe94f82bULL ),
	cpu_to_be64 ( 0xa54ff53a5f1d36f1ULL ),
	cpu_to_be64 ( 0x510e527fade682d1ULL ),
	cpu_to_be64 ( 0x9b05688c2b3e6c1fULL ),
	cpu_to_be64 ( 0x1f83d9abfb41bd6bULL ),
	cpu_to_be64 ( 0x5be0cd19137e2179ULL ),
	},
	};

	/**
	* Initialise SHA-512 family algorithm
	*
	* @v context SHA-512 context
	* @v init Initial digest values
	* @v digestsize Digest size
	*/
	void sha512_family_init ( struct sha512_context *context,
	const struct sha512_digest *init,
	size_t digestsize ) {

	context->len = 0;
	context->digestsize = digestsize;
	memcpy ( &context->ddq.dd.digest, init,
	sizeof ( context->ddq.dd.digest ) );
	}

	/**
	* Initialise SHA-512 algorithm
	*
	* @v ctx SHA-512 context
	*/
	static void sha512_init ( void *ctx ) {
	struct sha512_context *context = ctx;

	sha512_family_init ( context, &sha512_init_digest,
	sizeof ( struct sha512_digest ) );
	}

	/**
	* Calculate SHA-512 digest of accumulated data
	*
	* @v context SHA-512 context
	*/
	static void sha512_digest ( struct sha512_context *context ) {
	union {
	union sha512_digest_data_qwords ddq;
	struct sha512_variables v;
	} u;
	uint64_t *a = &u.v.a;
	uint64_t *b = &u.v.b;
	uint64_t *c = &u.v.c;
	uint64_t *d = &u.v.d;
	uint64_t *e = &u.v.e;
	uint64_t *f = &u.v.f;
	uint64_t *g = &u.v.g;
	uint64_t *h = &u.v.h;
	uint64_t *w = u.v.w;
	uint64_t s0;
	uint64_t s1;
	uint64_t maj;
	uint64_t t1;
	uint64_t t2;
	uint64_t ch;
	unsigned int i;

	/* Sanity checks */
	assert ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 );
	build_assert ( &u.ddq.dd.digest.h[0] == a );
	build_assert ( &u.ddq.dd.digest.h[1] == b );
	build_assert ( &u.ddq.dd.digest.h[2] == c );
	build_assert ( &u.ddq.dd.digest.h[3] == d );
	build_assert ( &u.ddq.dd.digest.h[4] == e );
	build_assert ( &u.ddq.dd.digest.h[5] == f );
	build_assert ( &u.ddq.dd.digest.h[6] == g );
	build_assert ( &u.ddq.dd.digest.h[7] == h );
	build_assert ( &u.ddq.dd.data.qword[0] == w );

	DBGC ( context, "SHA512 digesting:\n" );
	DBGC_HDA ( context, 0, &context->ddq.dd.digest,
	sizeof ( context->ddq.dd.digest ) );
	DBGC_HDA ( context, context->len, &context->ddq.dd.data,
	sizeof ( context->ddq.dd.data ) );

	/* Convert h[0..7] to host-endian, and initialise a, b, c, d,
	* e, f, g, h, and w[0..15]
	*/
	for ( i = 0 ; i < ( sizeof ( u.ddq.qword ) /
	sizeof ( u.ddq.qword[0] ) ) ; i++ ) {
	be64_to_cpus ( &context->ddq.qword[i] );
	u.ddq.qword[i] = context->ddq.qword[i];
	}

	/* Initialise w[16..79] */
	for ( i = 16 ; i < SHA512_ROUNDS ; i++ ) {
	s0 = ( ror64 ( w[i-15], 1 ) ^ ror64 ( w[i-15], 8 ) ^
	( w[i-15] >> 7 ) );
	s1 = ( ror64 ( w[i-2], 19 ) ^ ror64 ( w[i-2], 61 ) ^
	( w[i-2] >> 6 ) );
	w[i] = ( w[i-16] + s0 + w[i-7] + s1 );
	}

	/* Main loop */
	for ( i = 0 ; i < SHA512_ROUNDS ; i++ ) {
	s0 = ( ror64 ( a, 28 ) ^ ror64 ( a, 34 ) ^ ror64 ( *a, 39 ) );
	maj = ( ( a & b ) ^ ( a & c ) ^ ( b & c ) );
	t2 = ( s0 + maj );
	s1 = ( ror64 ( e, 14 ) ^ ror64 ( e, 18 ) ^ ror64 ( *e, 41 ) );
	ch = ( ( e & f ) ^ ( (~e) & g ) );
	t1 = ( *h + s1 + ch + k[i] + w[i] );
	h = g;
	g = f;
	f = e;
	e = ( d + t1 );
	d = c;
	c = b;
	b = a;
	*a = ( t1 + t2 );
	DBGC2 ( context, "%2d : %016llx %016llx %016llx %016llx "
	"%016llx %016llx %016llx %016llx\n",
	i, a, b, c, d, e, f, g, h );
	}

	/* Add chunk to hash and convert back to big-endian */
	for ( i = 0 ; i < 8 ; i++ ) {
	context->ddq.dd.digest.h[i] =
	cpu_to_be64 ( context->ddq.dd.digest.h[i] +
	u.ddq.dd.digest.h[i] );
	}

	DBGC ( context, "SHA512 digested:\n" );
	DBGC_HDA ( context, 0, &context->ddq.dd.digest,
	sizeof ( context->ddq.dd.digest ) );
	}

	/**
	* Accumulate data with SHA-512 algorithm
	*
	* @v ctx SHA-512 context
	* @v data Data
	* @v len Length of data
	*/
	void sha512_update ( void ctx, const void data, size_t len ) {
	struct sha512_context *context = ctx;
	const uint8_t *byte = data;
	size_t offset;

	/* Accumulate data a byte at a time, performing the digest
	* whenever we fill the data buffer
	*/
	while ( len-- ) {
	offset = ( context->len % sizeof ( context->ddq.dd.data ) );
	context->ddq.dd.data.byte[offset] = *(byte++);
	context->len++;
	if ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 )
	sha512_digest ( context );
	}
	}

	/**
	* Generate SHA-512 digest
	*
	* @v ctx SHA-512 context
	* @v out Output buffer
	*/
	void sha512_final ( void ctx, void out ) {
	struct sha512_context *context = ctx;
	uint64_t len_bits_hi;
	uint64_t len_bits_lo;
	uint8_t pad;

	/* Record length before pre-processing */
	len_bits_hi = 0;
	len_bits_lo = cpu_to_be64 ( ( ( uint64_t ) context->len ) * 8 );

	/* Pad with a single "1" bit followed by as many "0" bits as required */
	pad = 0x80;
	do {
	sha512_update ( ctx, &pad, sizeof ( pad ) );
	pad = 0x00;
	} while ( ( context->len % sizeof ( context->ddq.dd.data ) ) !=
	offsetof ( typeof ( context->ddq.dd.data ), final.len_hi ) );

	/* Append length (in bits) */
	sha512_update ( ctx, &len_bits_hi, sizeof ( len_bits_hi ) );
	sha512_update ( ctx, &len_bits_lo, sizeof ( len_bits_lo ) );
	assert ( ( context->len % sizeof ( context->ddq.dd.data ) ) == 0 );

	/* Copy out final digest */
	memcpy ( out, &context->ddq.dd.digest, context->digestsize );
	}

	/** SHA-512 algorithm */
	struct digest_algorithm sha512_algorithm = {
	.name = "sha512",
	.ctxsize = sizeof ( struct sha512_context ),
	.blocksize = sizeof ( union sha512_block ),
	.digestsize = sizeof ( struct sha512_digest ),
	.init = sha512_init,
	.update = sha512_update,
	.final = sha512_final,
	};