[CRYPTO] digest: Added user API for new hash type

The existing digest user interface is inadequate for support asynchronous
operations.  For one it doesn't return a value to indicate success or
failure, nor does it take a per-operation descriptor which is essential
for the issuing of requests while other requests are still outstanding.

This patch is the first in a series of steps to remodel the interface
for asynchronous operations.

For the ease of transition the new interface will be known as "hash"
while the old one will remain as "digest".

This patch also changes sg_next to allow chaining.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 102 insertions, 27 deletions

diff --git a/crypto/digest.c b/crypto/digest.c
index 96244a528844..5873063db840 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -11,29 +11,89 @@
  * any later version.
  *
  */
-#include <linux/crypto.h>
+
 #include <linux/mm.h>
 #include <linux/errno.h>
 #include <linux/highmem.h>
-#include <asm/scatterlist.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+
 #include "internal.h"
+#include "scatterwalk.h"
 
-static void init(struct crypto_tfm *tfm)
+void crypto_digest_init(struct crypto_tfm *tfm)
 {
-	tfm->__crt_alg->cra_digest.dia_init(tfm);
+	struct crypto_hash *hash = crypto_hash_cast(tfm);
+	struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
+
+	crypto_hash_init(&desc);
 }
+EXPORT_SYMBOL_GPL(crypto_digest_init);
 
-static void update(struct crypto_tfm *tfm,
-                   struct scatterlist *sg, unsigned int nsg)
+void crypto_digest_update(struct crypto_tfm *tfm,
+			  struct scatterlist *sg, unsigned int nsg)
 {
+	struct crypto_hash *hash = crypto_hash_cast(tfm);
+	struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
+	unsigned int nbytes = 0;
 	unsigned int i;
+
+	for (i = 0; i < nsg; i++)
+		nbytes += sg[i].length;
+
+	crypto_hash_update(&desc, sg, nbytes);
+}
+EXPORT_SYMBOL_GPL(crypto_digest_update);
+
+void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
+{
+	struct crypto_hash *hash = crypto_hash_cast(tfm);
+	struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
+
+	crypto_hash_final(&desc, out);
+}
+EXPORT_SYMBOL_GPL(crypto_digest_final);
+
+void crypto_digest_digest(struct crypto_tfm *tfm,
+			  struct scatterlist *sg, unsigned int nsg, u8 *out)
+{
+	struct crypto_hash *hash = crypto_hash_cast(tfm);
+	struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
+	unsigned int nbytes = 0;
+	unsigned int i;
+
+	for (i = 0; i < nsg; i++)
+		nbytes += sg[i].length;
+
+	crypto_hash_digest(&desc, sg, nbytes, out);
+}
+EXPORT_SYMBOL_GPL(crypto_digest_digest);
+
+static int init(struct hash_desc *desc)
+{
+	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
+
+	tfm->__crt_alg->cra_digest.dia_init(tfm);
+	return 0;
+}
+
+static int update(struct hash_desc *desc,
+		  struct scatterlist *sg, unsigned int nbytes)
+{
+	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
 	unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
 
-	for (i = 0; i < nsg; i++) {
+	if (!nbytes)
+		return 0;
+
+	for (;;) {
+		struct page *pg = sg->page;
+		unsigned int offset = sg->offset;
+		unsigned int l = sg->length;
 
-		struct page *pg = sg[i].page;
-		unsigned int offset = sg[i].offset;
-		unsigned int l = sg[i].length;
+		if (unlikely(l > nbytes))
+			l = nbytes;
+		nbytes -= l;
 
 		do {
 			unsigned int bytes_from_page = min(l, ((unsigned int)
@@ -55,16 +115,23 @@ static void update(struct crypto_tfm *tfm,
 			tfm->__crt_alg->cra_digest.dia_update(tfm, p,
 							      bytes_from_page);
 			crypto_kunmap(src, 0);
-			crypto_yield(tfm->crt_flags);
+			crypto_yield(desc->flags);
 			offset = 0;
 			pg++;
 			l -= bytes_from_page;
 		} while (l > 0);
+
+		if (!nbytes)
+			break;
+		sg = sg_next(sg);
 	}
+
+	return 0;
 }
 
-static void final(struct crypto_tfm *tfm, u8 *out)
+static int final(struct hash_desc *desc, u8 *out)
 {
+	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
 	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 	struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
 
@@ -78,26 +145,30 @@ static void final(struct crypto_tfm *tfm, u8 *out)
 		memcpy(out, dst, digest->dia_digestsize);
 	} else
 		digest->dia_final(tfm, out);
+
+	return 0;
 }
 
-static int nosetkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
 {
-	tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+	crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
 	return -ENOSYS;
 }
 
-static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
 {
-	tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+	struct crypto_tfm *tfm = crypto_hash_tfm(hash);
+
+	crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
 	return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
 }
 
-static void digest(struct crypto_tfm *tfm,
-                   struct scatterlist *sg, unsigned int nsg, u8 *out)
+static int digest(struct hash_desc *desc,
+		  struct scatterlist *sg, unsigned int nbytes, u8 *out)
 {
-	init(tfm);
-	update(tfm, sg, nsg);
-	final(tfm, out);
+	init(desc);
+	update(desc, sg, nbytes);
+	return final(desc, out);
 }
 
 int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
@@ -107,14 +178,18 @@ int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
 
 int crypto_init_digest_ops(struct crypto_tfm *tfm)
 {
-	struct digest_tfm *ops = &tfm->crt_digest;
+	struct hash_tfm *ops = &tfm->crt_hash;
 	struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
+
+	if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
+		return -EINVAL;
 	
-	ops->dit_init	= init;
-	ops->dit_update	= update;
-	ops->dit_final	= final;
-	ops->dit_digest	= digest;
-	ops->dit_setkey	= dalg->dia_setkey ? setkey : nosetkey;
+	ops->init	= init;
+	ops->update	= update;
+	ops->final	= final;
+	ops->digest	= digest;
+	ops->setkey	= dalg->dia_setkey ? setkey : nosetkey;
+	ops->digestsize	= dalg->dia_digestsize;
 	
 	return crypto_alloc_hmac_block(tfm);
 }