diff --git a/crypto/digest.c b/crypto/digest.c
new file mode 100644
index 0000000..d9b6ac9
--- /dev/null
+++ b/crypto/digest.c
@@ -0,0 +1,107 @@
+/*
+ * Cryptographic API.
+ *
+ * Digest operations.
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ *
+ * 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/crypto.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/highmem.h>
+#include <asm/scatterlist.h>
+#include "internal.h"
+
+static void init(struct crypto_tfm *tfm)
+{
+	tfm->__crt_alg->cra_digest.dia_init(crypto_tfm_ctx(tfm));
+}
+
+static void update(struct crypto_tfm *tfm,
+                   struct scatterlist *sg, unsigned int nsg)
+{
+	unsigned int i;
+
+	for (i = 0; i < nsg; i++) {
+
+		struct page *pg = sg[i].page;
+		unsigned int offset = sg[i].offset;
+		unsigned int l = sg[i].length;
+
+		do {
+			unsigned int bytes_from_page = min(l, ((unsigned int)
+							   (PAGE_SIZE)) - 
+							   offset);
+			char *p = crypto_kmap(pg, 0) + offset;
+
+			tfm->__crt_alg->cra_digest.dia_update
+					(crypto_tfm_ctx(tfm), p,
+					 bytes_from_page);
+			crypto_kunmap(p, 0);
+			crypto_yield(tfm);
+			offset = 0;
+			pg++;
+			l -= bytes_from_page;
+		} while (l > 0);
+	}
+}
+
+static void final(struct crypto_tfm *tfm, u8 *out)
+{
+	tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
+}
+
+static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+{
+	u32 flags;
+	if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
+		return -ENOSYS;
+	return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
+						     key, keylen, &flags);
+}
+
+static void digest(struct crypto_tfm *tfm,
+                   struct scatterlist *sg, unsigned int nsg, u8 *out)
+{
+	unsigned int i;
+
+	tfm->crt_digest.dit_init(tfm);
+		
+	for (i = 0; i < nsg; i++) {
+		char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
+		tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
+		                                      p, sg[i].length);
+		crypto_kunmap(p, 0);
+		crypto_yield(tfm);
+	}
+	crypto_digest_final(tfm, out);
+}
+
+int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
+{
+	return flags ? -EINVAL : 0;
+}
+
+int crypto_init_digest_ops(struct crypto_tfm *tfm)
+{
+	struct digest_tfm *ops = &tfm->crt_digest;
+	
+	ops->dit_init	= init;
+	ops->dit_update	= update;
+	ops->dit_final	= final;
+	ops->dit_digest	= digest;
+	ops->dit_setkey	= setkey;
+	
+	return crypto_alloc_hmac_block(tfm);
+}
+
+void crypto_exit_digest_ops(struct crypto_tfm *tfm)
+{
+	crypto_free_hmac_block(tfm);
+}