[PATCH] s390: sha256 crypto code fix

Fix processing of messages larger than 2 * SHA256_BLOCK_SIZE.

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, 22 insertions, 7 deletions

diff --git a/arch/s390/crypto/sha256_s390.c b/arch/s390/crypto/sha256_s390.c
index b75bdbd476c7..1ec5e92b3454 100644
--- a/arch/s390/crypto/sha256_s390.c
+++ b/arch/s390/crypto/sha256_s390.c
@@ -51,6 +51,7 @@ static void sha256_update(void *ctx, const u8 *data, unsigned int len)
 {
         struct s390_sha256_ctx *sctx = ctx;
         unsigned int index;
+        int ret;
 
         /* how much is already in the buffer? */
         index = sctx->count / 8 & 0x3f;
@@ -58,15 +59,29 @@ static void sha256_update(void *ctx, const u8 *data, unsigned int len)
         /* update message bit length */
         sctx->count += len * 8;
 
-        /* process one block */
-        if ((index + len) >= SHA256_BLOCK_SIZE) {
+        if ((index + len) < SHA256_BLOCK_SIZE)
+                goto store;
+
+        /* process one stored block */
+        if (index) {
                 memcpy(sctx->buf + index, data, SHA256_BLOCK_SIZE - index);
-                crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
-                                SHA256_BLOCK_SIZE);
+                ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
+                                      SHA256_BLOCK_SIZE);
+                BUG_ON(ret != SHA256_BLOCK_SIZE);
                 data += SHA256_BLOCK_SIZE - index;
                 len -= SHA256_BLOCK_SIZE - index;
         }
 
+        /* process as many blocks as possible */
+        if (len >= SHA256_BLOCK_SIZE) {
+                ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, data,
+                                      len & ~(SHA256_BLOCK_SIZE - 1));
+                BUG_ON(ret != (len & ~(SHA256_BLOCK_SIZE - 1)));
+                data += ret;
+                len -= ret;
+        }
+
+store:
         /* anything left? */
         if (len)
                 memcpy(sctx->buf + index , data, len);
@@ -119,9 +134,9 @@ static struct crypto_alg alg = {
         .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 } }
+        .dia_init       =       sha256_init,
+        .dia_update     =       sha256_update,
+        .dia_final      =       sha256_final } }
 };
 
 static int init(void)