[CRYPTO] hash: Add asynchronous hash support

This patch adds asynchronous hash and digest support.

Signed-off-by: Loc Ho <lho@amcc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 106 insertions, 0 deletions

diff --git a/crypto/ahash.c b/crypto/ahash.c
new file mode 100644
index 0000000..a83e035
--- /dev/null
+++ b/crypto/ahash.c
@@ -0,0 +1,106 @@
+/*
+ * Asynchronous Cryptographic Hash operations.
+ *
+ * This is the asynchronous version of hash.c with notification of
+ * completion via a callback.
+ *
+ * Copyright (c) 2008 Loc Ho <lho@amcc.com>
+ *
+ * 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 <crypto/algapi.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+
+#include "internal.h"
+
+static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
+				unsigned int keylen)
+{
+	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
+	unsigned long alignmask = crypto_ahash_alignmask(tfm);
+	int ret;
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+
+	absize = keylen + alignmask;
+	buffer = kmalloc(absize, GFP_ATOMIC);
+	if (!buffer)
+		return -ENOMEM;
+
+	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+	memcpy(alignbuffer, key, keylen);
+	ret = ahash->setkey(tfm, alignbuffer, keylen);
+	memset(alignbuffer, 0, keylen);
+	kfree(buffer);
+	return ret;
+}
+
+static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
+			unsigned int keylen)
+{
+	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
+	unsigned long alignmask = crypto_ahash_alignmask(tfm);
+
+	if ((unsigned long)key & alignmask)
+		return ahash_setkey_unaligned(tfm, key, keylen);
+
+	return ahash->setkey(tfm, key, keylen);
+}
+
+static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
+					u32 mask)
+{
+	return alg->cra_ctxsize;
+}
+
+static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+	struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
+	struct ahash_tfm *crt   = &tfm->crt_ahash;
+
+	if (alg->digestsize > crypto_tfm_alg_blocksize(tfm))
+		return -EINVAL;
+
+	crt->init = alg->init;
+	crt->update = alg->update;
+	crt->final  = alg->final;
+	crt->digest = alg->digest;
+	crt->setkey = ahash_setkey;
+	crt->base   = __crypto_ahash_cast(tfm);
+	crt->digestsize = alg->digestsize;
+
+	return 0;
+}
+
+static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	seq_printf(m, "type         : ahash\n");
+	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
+					     "yes" : "no");
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "digestsize   : %u\n", alg->cra_hash.digestsize);
+}
+
+const struct crypto_type crypto_ahash_type = {
+	.ctxsize = crypto_ahash_ctxsize,
+	.init = crypto_init_ahash_ops,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_ahash_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_ahash_type);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Asynchronous cryptographic hash type");