[crypto] Replace SHA-1 implementation

Replace SHA-1 implementation from AXTLS with a dedicated iPXE
implementation which is around 40% smaller.  This implementation has
been verified using the existing SHA-1 self-tests (including the NIST
SHA-1 test vectors).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 270 insertions, 0 deletions

diff --git a/src/crypto/sha1.c b/src/crypto/sha1.c
new file mode 100644
index 00000000..834d9a21
--- /dev/null
+++ b/src/crypto/sha1.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright (C) 2012 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * SHA-1 algorithm
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <byteswap.h>
+#include <assert.h>
+#include <ipxe/crypto.h>
+#include <ipxe/sha1.h>
+
+/**
+ * Rotate dword left
+ *
+ * @v dword		Dword
+ * @v rotate		Amount of rotation
+ */
+static inline __attribute__ (( always_inline )) uint32_t
+rol32 ( uint32_t dword, unsigned int rotate ) {
+	return ( ( dword << rotate ) | ( dword >> ( 32 - rotate ) ) );
+}
+
+/** SHA-1 variables */
+struct sha1_variables {
+	/* This layout matches that of struct sha1_digest_data,
+	 * allowing for efficient endianness-conversion,
+	 */
+	uint32_t a;
+	uint32_t b;
+	uint32_t c;
+	uint32_t d;
+	uint32_t e;
+	uint32_t w[80];
+} __attribute__ (( packed ));
+
+/**
+ * f(a,b,c,d) for steps 0 to 19
+ *
+ * @v v		SHA-1 variables
+ * @ret f	f(a,b,c,d)
+ */
+static uint32_t sha1_f_0_19 ( struct sha1_variables *v ) {
+	return ( ( v->b & v->c ) | ( (~v->b) & v->d ) );
+}
+
+/**
+ * f(a,b,c,d) for steps 20 to 39 and 60 to 79
+ *
+ * @v v		SHA-1 variables
+ * @ret f	f(a,b,c,d)
+ */
+static uint32_t sha1_f_20_39_60_79 ( struct sha1_variables *v ) {
+	return ( v->b ^ v->c ^ v->d );
+}
+
+/**
+ * f(a,b,c,d) for steps 40 to 59
+ *
+ * @v v		SHA-1 variables
+ * @ret f	f(a,b,c,d)
+ */
+static uint32_t sha1_f_40_59 ( struct sha1_variables *v ) {
+	return ( ( v->b & v->c ) | ( v->b & v->d ) | ( v->c & v->d ) );
+}
+
+/** An SHA-1 step function */
+struct sha1_step {
+	/**
+	 * Calculate f(a,b,c,d)
+	 *
+	 * @v v		SHA-1 variables
+	 * @ret f	f(a,b,c,d)
+	 */
+	uint32_t ( * f ) ( struct sha1_variables *v );
+	/** Constant k */
+	uint32_t k;
+};
+
+/** SHA-1 steps */
+static struct sha1_step sha1_steps[4] = {
+	/** 0 to 19 */
+	{ .f = sha1_f_0_19,		.k = 0x5a827999 },
+	/** 20 to 39 */
+	{ .f = sha1_f_20_39_60_79,	.k = 0x6ed9eba1 },
+	/** 40 to 59 */
+	{ .f = sha1_f_40_59,		.k = 0x8f1bbcdc },
+	/** 60 to 79 */
+	{ .f = sha1_f_20_39_60_79,	.k = 0xca62c1d6 },
+};
+
+/**
+ * Initialise SHA-1 algorithm
+ *
+ * @v ctx		SHA-1 context
+ */
+static void sha1_init ( void *ctx ) {
+	struct sha1_context *context = ctx;
+
+	context->ddd.dd.digest.h[0] = cpu_to_be32 ( 0x67452301 );
+	context->ddd.dd.digest.h[1] = cpu_to_be32 ( 0xefcdab89 );
+	context->ddd.dd.digest.h[2] = cpu_to_be32 ( 0x98badcfe );
+	context->ddd.dd.digest.h[3] = cpu_to_be32 ( 0x10325476 );
+	context->ddd.dd.digest.h[4] = cpu_to_be32 ( 0xc3d2e1f0 );
+	context->len = 0;
+}
+
+/**
+ * Calculate SHA-1 digest of accumulated data
+ *
+ * @v context		SHA-1 context
+ */
+static void sha1_digest ( struct sha1_context *context ) {
+        union {
+		union sha1_digest_data_dwords ddd;
+		struct sha1_variables v;
+	} u;
+	uint32_t *a = &u.v.a;
+	uint32_t *b = &u.v.b;
+	uint32_t *c = &u.v.c;
+	uint32_t *d = &u.v.d;
+	uint32_t *e = &u.v.e;
+	uint32_t *w = u.v.w;
+	uint32_t f;
+	uint32_t k;
+	uint32_t temp;
+	struct sha1_step *step;
+	unsigned int i;
+
+	/* Sanity checks */
+	assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
+	linker_assert ( &u.ddd.dd.digest.h[0] == a, sha1_bad_layout );
+	linker_assert ( &u.ddd.dd.digest.h[1] == b, sha1_bad_layout );
+	linker_assert ( &u.ddd.dd.digest.h[2] == c, sha1_bad_layout );
+	linker_assert ( &u.ddd.dd.digest.h[3] == d, sha1_bad_layout );
+	linker_assert ( &u.ddd.dd.digest.h[4] == e, sha1_bad_layout );
+	linker_assert ( &u.ddd.dd.data.dword[0] == w, sha1_bad_layout );
+
+	DBGC ( context, "SHA1 digesting:\n" );
+	DBGC_HDA ( context, 0, &context->ddd.dd.digest,
+		   sizeof ( context->ddd.dd.digest ) );
+	DBGC_HDA ( context, context->len, &context->ddd.dd.data,
+		   sizeof ( context->ddd.dd.data ) );
+
+	/* Convert h[0..4] to host-endian, and initialise a, b, c, d,
+	 * e, and w[0..15]
+	 */
+	for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
+			    sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
+		be32_to_cpus ( &context->ddd.dword[i] );
+		u.ddd.dword[i] = context->ddd.dword[i];
+	}
+
+	/* Initialise w[16..79] */
+	for ( i = 16 ; i < 80 ; i++ )
+		w[i] = rol32 ( ( w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16] ), 1 );
+
+	/* Main loop */
+	for ( i = 0 ; i < 80 ; i++ ) {
+		step = &sha1_steps[ i / 20 ];
+		f = step->f ( &u.v );
+		k = step->k;
+		temp = ( rol32 ( *a, 5 ) + f + *e + k + w[i] );
+		*e = *d;
+		*d = *c;
+		*c = rol32 ( *b, 30 );
+		*b = *a;
+		*a = temp;
+		DBGC2 ( context, "%2d : %08x %08x %08x %08x %08x\n",
+			i, *a, *b, *c, *d, *e );
+	}
+
+	/* Add chunk to hash and convert back to big-endian */
+	for ( i = 0 ; i < 5 ; i++ ) {
+		context->ddd.dd.digest.h[i] =
+			cpu_to_be32 ( context->ddd.dd.digest.h[i] +
+				      u.ddd.dd.digest.h[i] );
+	}
+
+	DBGC ( context, "SHA1 digested:\n" );
+	DBGC_HDA ( context, 0, &context->ddd.dd.digest,
+		   sizeof ( context->ddd.dd.digest ) );
+}
+
+/**
+ * Accumulate data with SHA-1 algorithm
+ *
+ * @v ctx		SHA-1 context
+ * @v data		Data
+ * @v len		Length of data
+ */
+static void sha1_update ( void *ctx, const void *data, size_t len ) {
+	struct sha1_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->ddd.dd.data ) );
+		context->ddd.dd.data.byte[offset] = *(byte++);
+		context->len++;
+		if ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 )
+			sha1_digest ( context );
+	}
+}
+
+/**
+ * Generate SHA-1 digest
+ *
+ * @v ctx		SHA-1 context
+ * @v out		Output buffer
+ */
+static void sha1_final ( void *ctx, void *out ) {
+	struct sha1_context *context = ctx;
+	uint64_t len_bits;
+	uint8_t pad;
+
+	/* Record length before pre-processing */
+	len_bits = 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 {
+		sha1_update ( ctx, &pad, sizeof ( pad ) );
+		pad = 0x00;
+	} while ( ( context->len % sizeof ( context->ddd.dd.data ) ) !=
+		  offsetof ( typeof ( context->ddd.dd.data ), final.len ) );
+
+	/* Append length (in bits) */
+	sha1_update ( ctx, &len_bits, sizeof ( len_bits ) );
+	assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
+
+	/* Copy out final digest */
+	memcpy ( out, &context->ddd.dd.digest,
+		 sizeof ( context->ddd.dd.digest ) );
+}
+
+/** SHA-1 algorithm */
+struct digest_algorithm sha1_algorithm = {
+	.name		= "sha1",
+	.ctxsize	= sizeof ( struct sha1_context ),
+	.blocksize	= sizeof ( union sha1_block ),
+	.digestsize	= sizeof ( struct sha1_digest ),
+	.init		= sha1_init,
+	.update		= sha1_update,
+	.final		= sha1_final,
+};