crypto: sha1_generic - Add export/import support

This patch adds export/import support to sha1_generic.  The exported
type is defined by struct sha1_state, which is basically the entire
descriptor state of sha1_generic.

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

2 files changed, 33 insertions, 16 deletions

diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
index 9efef20454cb..0416091bf45a 100644
--- a/crypto/sha1_generic.c
+++ b/crypto/sha1_generic.c
@@ -25,31 +25,21 @@
 #include <crypto/sha.h>
 #include <asm/byteorder.h>
 
-struct sha1_ctx {
-        u64 count;
-        u32 state[5];
-        u8 buffer[64];
-};
-
 static int sha1_init(struct shash_desc *desc)
 {
-        struct sha1_ctx *sctx = shash_desc_ctx(desc);
+        struct sha1_state *sctx = shash_desc_ctx(desc);
 
-        static const struct sha1_ctx initstate = {
-          0,
-          { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
-          { 0, }
+        *sctx = (struct sha1_state){
+                .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
         };
 
-        *sctx = initstate;
-
         return 0;
 }
 
 static int sha1_update(struct shash_desc *desc, const u8 *data,
                         unsigned int len)
 {
-        struct sha1_ctx *sctx = shash_desc_ctx(desc);
+        struct sha1_state *sctx = shash_desc_ctx(desc);
         unsigned int partial, done;
         const u8 *src;
 
@@ -85,7 +75,7 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
 /* Add padding and return the message digest. */
 static int sha1_final(struct shash_desc *desc, u8 *out)
 {
-        struct sha1_ctx *sctx = shash_desc_ctx(desc);
+        struct sha1_state *sctx = shash_desc_ctx(desc);
         __be32 *dst = (__be32 *)out;
         u32 i, index, padlen;
         __be64 bits;
@@ -111,12 +101,31 @@ static int sha1_final(struct shash_desc *desc, u8 *out)
         return 0;
 }
 
+static int sha1_export(struct shash_desc *desc, void *out)
+{
+        struct sha1_state *sctx = shash_desc_ctx(desc);
+
+        memcpy(out, sctx, sizeof(*sctx));
+        return 0;
+}
+
+static int sha1_import(struct shash_desc *desc, const void *in)
+{
+        struct sha1_state *sctx = shash_desc_ctx(desc);
+
+        memcpy(sctx, in, sizeof(*sctx));
+        return 0;
+}
+
 static struct shash_alg alg = {
         .digestsize     =       SHA1_DIGEST_SIZE,
         .init           =       sha1_init,
         .update         =       sha1_update,
         .final          =       sha1_final,
-        .descsize       =       sizeof(struct sha1_ctx),
+        .export         =       sha1_export,
+        .import         =       sha1_import,
+        .descsize       =       sizeof(struct sha1_state),
+        .statesize      =       sizeof(struct sha1_state),
         .base           =       {
                 .cra_name       =       "sha1",
                 .cra_driver_name=       "sha1-generic",
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index c0ccc2b1a2d8..922a248bd04d 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -5,6 +5,8 @@
 #ifndef _CRYPTO_SHA_H
 #define _CRYPTO_SHA_H
 
+#include <linux/types.h>
+
 #define SHA1_DIGEST_SIZE        20
 #define SHA1_BLOCK_SIZE         64
 
@@ -62,4 +64,10 @@
 #define SHA512_H6       0x1f83d9abfb41bd6bULL
 #define SHA512_H7       0x5be0cd19137e2179ULL
 
+struct sha1_state {
+        u64 count;
+        u32 state[SHA1_DIGEST_SIZE / 4];
+        u8 buffer[SHA1_BLOCK_SIZE];
+};
+
 #endif