[crypto] Add SHA-224 algorithm

SHA-224 is almost identical to SHA-256, with differing initial hash
values and a truncated output length.

This implementation has been verified using the NIST SHA-224 test
vectors.

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

src/crypto/sha224.c

@@ -0,0 +1,82 @@
+/*
+ * 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-224 algorithm
+ *
+ */
+
+#include <stdint.h>
+#include <byteswap.h>
+#include <ipxe/crypto.h>
+#include <ipxe/asn1.h>
+#include <ipxe/sha256.h>
+
+/** SHA-224 initial digest values */
+static const struct sha256_digest sha224_init_digest = {
+	.h = {
+		cpu_to_be32 ( 0xc1059ed8 ),
+		cpu_to_be32 ( 0x367cd507 ),
+		cpu_to_be32 ( 0x3070dd17 ),
+		cpu_to_be32 ( 0xf70e5939 ),
+		cpu_to_be32 ( 0xffc00b31 ),
+		cpu_to_be32 ( 0x68581511 ),
+		cpu_to_be32 ( 0x64f98fa7 ),
+		cpu_to_be32 ( 0xbefa4fa4 ),
+	},
+};
+
+/**
+ * Initialise SHA-224 algorithm
+ *
+ * @v ctx		SHA-224 context
+ */
+static void sha224_init ( void *ctx ) {
+	struct sha256_context *context = ctx;
+
+	sha256_family_init ( context, &sha224_init_digest, SHA224_DIGEST_SIZE );
+}
+
+/** SHA-224 algorithm */
+struct digest_algorithm sha224_algorithm = {
+	.name		= "sha224",
+	.ctxsize	= sizeof ( struct sha256_context ),
+	.blocksize	= sizeof ( union sha256_block ),
+	.digestsize	= SHA224_DIGEST_SIZE,
+	.init		= sha224_init,
+	.update		= sha256_update,
+	.final		= sha256_final,
+};
+
+/** "sha224" object identifier */
+static uint8_t oid_sha224[] = { ASN1_OID_SHA224 };
+
+/** "sha224" OID-identified algorithm */
+struct asn1_algorithm oid_sha224_algorithm __asn1_algorithm = {
+	.name = "sha224",
+	.digest = &sha224_algorithm,
+	.oid = ASN1_OID_CURSOR ( oid_sha224 ),
+};

src/crypto/sha256.c

@@ -69,6 +69,37 @@ static const uint32_t k[64] = {
 	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };
 
+/** SHA-256 initial digest values */
+static const struct sha256_digest sha256_init_digest = {
+	.h = {
+		cpu_to_be32 ( 0x6a09e667 ),
+		cpu_to_be32 ( 0xbb67ae85 ),
+		cpu_to_be32 ( 0x3c6ef372 ),
+		cpu_to_be32 ( 0xa54ff53a ),
+		cpu_to_be32 ( 0x510e527f ),
+		cpu_to_be32 ( 0x9b05688c ),
+		cpu_to_be32 ( 0x1f83d9ab ),
+		cpu_to_be32 ( 0x5be0cd19 ),
+	},
+};
+
+/**
+ * Initialise SHA-256 family algorithm
+ *
+ * @v context		SHA-256 context
+ * @v init		Initial digest values
+ * @v digestsize	Digest size
+ */
+void sha256_family_init ( struct sha256_context *context,
+			  const struct sha256_digest *init,
+			  size_t digestsize ) {
+
+	context->len = 0;
+	context->digestsize = digestsize;
+	memcpy ( &context->ddd.dd.digest, init,
+		 sizeof ( context->ddd.dd.digest ) );
+}
+
 /**
  * Initialise SHA-256 algorithm
  *
@@ -77,15 +108,8 @@ static const uint32_t k[64] = {
 static void sha256_init ( void *ctx ) {
 	struct sha256_context *context = ctx;
 
-	context->ddd.dd.digest.h[0] = cpu_to_be32 ( 0x6a09e667 );
-	context->ddd.dd.digest.h[1] = cpu_to_be32 ( 0xbb67ae85 );
-	context->ddd.dd.digest.h[2] = cpu_to_be32 ( 0x3c6ef372 );
-	context->ddd.dd.digest.h[3] = cpu_to_be32 ( 0xa54ff53a );
-	context->ddd.dd.digest.h[4] = cpu_to_be32 ( 0x510e527f );
-	context->ddd.dd.digest.h[5] = cpu_to_be32 ( 0x9b05688c );
-	context->ddd.dd.digest.h[6] = cpu_to_be32 ( 0x1f83d9ab );
-	context->ddd.dd.digest.h[7] = cpu_to_be32 ( 0x5be0cd19 );
-	context->len = 0;
+	sha256_family_init ( context, &sha256_init_digest,
+			     sizeof ( struct sha256_digest ) );
 }
 
 /**
@@ -190,7 +214,7 @@ static void sha256_digest ( struct sha256_context *context ) {
  * @v data		Data
  * @v len		Length of data
  */
-static void sha256_update ( void *ctx, const void *data, size_t len ) {
+void sha256_update ( void *ctx, const void *data, size_t len ) {
 	struct sha256_context *context = ctx;
 	const uint8_t *byte = data;
 	size_t offset;
@@ -213,7 +237,7 @@ static void sha256_update ( void *ctx, const void *data, size_t len ) {
  * @v ctx		SHA-256 context
  * @v out		Output buffer
  */
-static void sha256_final ( void *ctx, void *out ) {
+void sha256_final ( void *ctx, void *out ) {
 	struct sha256_context *context = ctx;
 	uint64_t len_bits;
 	uint8_t pad;
@@ -234,8 +258,7 @@ static void sha256_final ( void *ctx, void *out ) {
 	assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
 
 	/* Copy out final digest */
-	memcpy ( out, &context->ddd.dd.digest,
-		 sizeof ( context->ddd.dd.digest ) );
+	memcpy ( out, &context->ddd.dd.digest, context->digestsize );
 }
 
 /** SHA-256 algorithm */