[CRYPTO] sha: Load the SHA[1|256] module by an alias

Loading the crypto algorithm by the alias instead of by module directly
has the advantage that all possible implementations of this algorithm
are loaded automatically and the crypto API can choose the best one
depending on its priority.

Additionally it ensures that the generic implementation as well as the
HW driver (if available) is loaded in case the HW driver needs the
generic version as fallback in corner cases.

Also remove the probe for sha1 in padlock's init code.

Quote from Herbert:
  The probe is actually pointless since we can always probe when
  the algorithm is actually used which does not lead to dead-locks
  like this.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 142 insertions, 0 deletions

diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
new file mode 100644
index 0000000..70364dd
--- /dev/null
+++ b/crypto/sha1_generic.c
@@ -0,0 +1,142 @@
+/*
+ * Cryptographic API.
+ *
+ * SHA1 Secure Hash Algorithm.
+ *
+ * Derived from cryptoapi implementation, adapted for in-place
+ * scatterlist interface.
+ *
+ * Copyright (c) Alan Smithee.
+ * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
+ * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
+ *
+ * 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/mm.h>
+#include <linux/crypto.h>
+#include <linux/cryptohash.h>
+#include <linux/types.h>
+#include <asm/scatterlist.h>
+#include <asm/byteorder.h>
+
+#define SHA1_DIGEST_SIZE	20
+#define SHA1_HMAC_BLOCK_SIZE	64
+
+struct sha1_ctx {
+        u64 count;
+        u32 state[5];
+        u8 buffer[64];
+};
+
+static void sha1_init(struct crypto_tfm *tfm)
+{
+	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	static const struct sha1_ctx initstate = {
+	  0,
+	  { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
+	  { 0, }
+	};
+
+	*sctx = initstate;
+}
+
+static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
+			unsigned int len)
+{
+	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	unsigned int partial, done;
+	const u8 *src;
+
+	partial = sctx->count & 0x3f;
+	sctx->count += len;
+	done = 0;
+	src = data;
+
+	if ((partial + len) > 63) {
+		u32 temp[SHA_WORKSPACE_WORDS];
+
+		if (partial) {
+			done = -partial;
+			memcpy(sctx->buffer + partial, data, done + 64);
+			src = sctx->buffer;
+		}
+
+		do {
+			sha_transform(sctx->state, src, temp);
+			done += 64;
+			src = data + done;
+		} while (done + 63 < len);
+
+		memset(temp, 0, sizeof(temp));
+		partial = 0;
+	}
+	memcpy(sctx->buffer + partial, src, len - done);
+}
+
+
+/* Add padding and return the message digest. */
+static void sha1_final(struct crypto_tfm *tfm, u8 *out)
+{
+	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
+	__be32 *dst = (__be32 *)out;
+	u32 i, index, padlen;
+	__be64 bits;
+	static const u8 padding[64] = { 0x80, };
+
+	bits = cpu_to_be64(sctx->count << 3);
+
+	/* Pad out to 56 mod 64 */
+	index = sctx->count & 0x3f;
+	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
+	sha1_update(tfm, padding, padlen);
+
+	/* Append length */
+	sha1_update(tfm, (const u8 *)&bits, sizeof(bits));
+
+	/* Store state in digest */
+	for (i = 0; i < 5; i++)
+		dst[i] = cpu_to_be32(sctx->state[i]);
+
+	/* Wipe context */
+	memset(sctx, 0, sizeof *sctx);
+}
+
+static struct crypto_alg alg = {
+	.cra_name	=	"sha1",
+	.cra_driver_name=	"sha1-generic",
+	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
+	.cra_blocksize	=	SHA1_HMAC_BLOCK_SIZE,
+	.cra_ctxsize	=	sizeof(struct sha1_ctx),
+	.cra_module	=	THIS_MODULE,
+	.cra_alignmask	=	3,
+	.cra_list       =       LIST_HEAD_INIT(alg.cra_list),
+	.cra_u		=	{ .digest = {
+	.dia_digestsize	=	SHA1_DIGEST_SIZE,
+	.dia_init   	= 	sha1_init,
+	.dia_update 	=	sha1_update,
+	.dia_final  	=	sha1_final } }
+};
+
+static int __init init(void)
+{
+	return crypto_register_alg(&alg);
+}
+
+static void __exit fini(void)
+{
+	crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
+
+MODULE_ALIAS("sha1");