[PATCH] s390: sha256 support

Add support for the hardware accelerated sha256 crypto algorithm.

Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 151 insertions, 0 deletions

diff --git a/arch/s390/crypto/sha256_s390.c b/arch/s390/crypto/sha256_s390.c
new file mode 100644
index 000000000000..b75bdbd476c7
--- /dev/null
+++ b/arch/s390/crypto/sha256_s390.c
@@ -0,0 +1,151 @@
+/*
+ * Cryptographic API.
+ *
+ * s390 implementation of the SHA256 Secure Hash Algorithm.
+ *
+ * s390 Version:
+ *   Copyright (C) 2005 IBM Deutschland GmbH, IBM Corporation
+ *   Author(s): Jan Glauber (jang@de.ibm.com)
+ *
+ * Derived from "crypto/sha256.c"
+ * and "arch/s390/crypto/sha1_s390.c"
+ *
+ * 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 (at your option)
+ * any later version.
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+
+#include "crypt_s390.h"
+
+#define SHA256_DIGEST_SIZE	32
+#define SHA256_BLOCK_SIZE	64
+
+struct s390_sha256_ctx {
+	u64 count;
+	u32 state[8];
+	u8 buf[2 * SHA256_BLOCK_SIZE];
+};
+
+static void sha256_init(void *ctx)
+{
+	struct s390_sha256_ctx *sctx = ctx;
+
+	sctx->state[0] = 0x6a09e667;
+	sctx->state[1] = 0xbb67ae85;
+	sctx->state[2] = 0x3c6ef372;
+	sctx->state[3] = 0xa54ff53a;
+	sctx->state[4] = 0x510e527f;
+	sctx->state[5] = 0x9b05688c;
+	sctx->state[6] = 0x1f83d9ab;
+	sctx->state[7] = 0x5be0cd19;
+	sctx->count = 0;
+	memset(sctx->buf, 0, sizeof(sctx->buf));
+}
+
+static void sha256_update(void *ctx, const u8 *data, unsigned int len)
+{
+	struct s390_sha256_ctx *sctx = ctx;
+	unsigned int index;
+
+	/* how much is already in the buffer? */
+	index = sctx->count / 8 & 0x3f;
+
+	/* update message bit length */
+	sctx->count += len * 8;
+
+	/* process one block */
+	if ((index + len) >= SHA256_BLOCK_SIZE) {
+		memcpy(sctx->buf + index, data, SHA256_BLOCK_SIZE - index);
+		crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
+				SHA256_BLOCK_SIZE);
+		data += SHA256_BLOCK_SIZE - index;
+		len -= SHA256_BLOCK_SIZE - index;
+	}
+
+	/* anything left? */
+	if (len)
+		memcpy(sctx->buf + index , data, len);
+}
+
+static void pad_message(struct s390_sha256_ctx* sctx)
+{
+	int index, end;
+
+	index = sctx->count / 8 & 0x3f;
+	end = index < 56 ? SHA256_BLOCK_SIZE : 2 * SHA256_BLOCK_SIZE;
+
+	/* start pad with 1 */
+	sctx->buf[index] = 0x80;
+
+	/* pad with zeros */
+	index++;
+	memset(sctx->buf + index, 0x00, end - index - 8);
+
+	/* append message length */
+	memcpy(sctx->buf + end - 8, &sctx->count, sizeof sctx->count);
+
+	sctx->count = end * 8;
+}
+
+/* Add padding and return the message digest */
+static void sha256_final(void* ctx, u8 *out)
+{
+	struct s390_sha256_ctx *sctx = ctx;
+
+	/* must perform manual padding */
+	pad_message(sctx);
+
+	crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
+			sctx->count / 8);
+
+	/* copy digest to out */
+	memcpy(out, sctx->state, SHA256_DIGEST_SIZE);
+
+	/* wipe context */
+	memset(sctx, 0, sizeof *sctx);
+}
+
+static struct crypto_alg alg = {
+	.cra_name	=	"sha256",
+	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
+	.cra_blocksize	=	SHA256_BLOCK_SIZE,
+	.cra_ctxsize	=	sizeof(struct s390_sha256_ctx),
+	.cra_module	=	THIS_MODULE,
+	.cra_list	=	LIST_HEAD_INIT(alg.cra_list),
+	.cra_u		=	{ .digest = {
+	.dia_digestsize	=	SHA256_DIGEST_SIZE,
+	.dia_init   	= 	sha256_init,
+	.dia_update 	=	sha256_update,
+	.dia_final  	=	sha256_final } }
+};
+
+static int init(void)
+{
+	int ret;
+
+	if (!crypt_s390_func_available(KIMD_SHA_256))
+		return -ENOSYS;
+
+	ret = crypto_register_alg(&alg);
+	if (ret != 0)
+		printk(KERN_INFO "crypt_s390: sha256_s390 couldn't be loaded.");
+	return ret;
+}
+
+static void __exit fini(void)
+{
+	crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_ALIAS("sha256");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm");