crypto: sha256-generic - move to generic glue implementation

This updates the generic SHA-256 implementation to use the
new shared SHA-256 glue code.

It also implements a .finup hook crypto_sha256_finup() and exports
it to other modules. The import and export() functions and the
.statesize member are dropped, since the default implementation
is perfectly suitable for this module.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 23 insertions, 113 deletions

diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c
index b001ff5c2efc..78431163ed3c 100644
--- a/crypto/sha256_generic.c
+++ b/crypto/sha256_generic.c
@@ -23,6 +23,7 @@
 #include <linux/mm.h>
 #include <linux/types.h>
 #include <crypto/sha.h>
+#include <crypto/sha256_base.h>
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
 
@@ -214,138 +215,43 @@ static void sha256_transform(u32 *state, const u8 *input)
         memzero_explicit(W, 64 * sizeof(u32));
 }
 
-static int sha224_init(struct shash_desc *desc)
+static void sha256_generic_block_fn(struct sha256_state *sst, u8 const *src,
+                                    int blocks)
 {
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-        sctx->state[0] = SHA224_H0;
-        sctx->state[1] = SHA224_H1;
-        sctx->state[2] = SHA224_H2;
-        sctx->state[3] = SHA224_H3;
-        sctx->state[4] = SHA224_H4;
-        sctx->state[5] = SHA224_H5;
-        sctx->state[6] = SHA224_H6;
-        sctx->state[7] = SHA224_H7;
-        sctx->count = 0;
-
-        return 0;
-}
-
-static int sha256_init(struct shash_desc *desc)
-{
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-        sctx->state[0] = SHA256_H0;
-        sctx->state[1] = SHA256_H1;
-        sctx->state[2] = SHA256_H2;
-        sctx->state[3] = SHA256_H3;
-        sctx->state[4] = SHA256_H4;
-        sctx->state[5] = SHA256_H5;
-        sctx->state[6] = SHA256_H6;
-        sctx->state[7] = SHA256_H7;
-        sctx->count = 0;
-
-        return 0;
+        while (blocks--) {
+                sha256_transform(sst->state, src);
+                src += SHA256_BLOCK_SIZE;
+        }
 }
 
 int crypto_sha256_update(struct shash_desc *desc, const u8 *data,
                           unsigned int len)
 {
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-        unsigned int partial, done;
-        const u8 *src;
-
-        partial = sctx->count & 0x3f;
-        sctx->count += len;
-        done = 0;
-        src = data;
-
-        if ((partial + len) > 63) {
-                if (partial) {
-                        done = -partial;
-                        memcpy(sctx->buf + partial, data, done + 64);
-                        src = sctx->buf;
-                }
-
-                do {
-                        sha256_transform(sctx->state, src);
-                        done += 64;
-                        src = data + done;
-                } while (done + 63 < len);
-
-                partial = 0;
-        }
-        memcpy(sctx->buf + partial, src, len - done);
-
-        return 0;
+        return sha256_base_do_update(desc, data, len, sha256_generic_block_fn);
 }
 EXPORT_SYMBOL(crypto_sha256_update);
 
 static int sha256_final(struct shash_desc *desc, u8 *out)
 {
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-        __be32 *dst = (__be32 *)out;
-        __be64 bits;
-        unsigned int index, pad_len;
-        int i;
-        static const u8 padding[64] = { 0x80, };
-
-        /* Save number of bits */
-        bits = cpu_to_be64(sctx->count << 3);
-
-        /* Pad out to 56 mod 64. */
-        index = sctx->count & 0x3f;
-        pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
-        crypto_sha256_update(desc, padding, pad_len);
-
-        /* Append length (before padding) */
-        crypto_sha256_update(desc, (const u8 *)&bits, sizeof(bits));
-
-        /* Store state in digest */
-        for (i = 0; i < 8; i++)
-                dst[i] = cpu_to_be32(sctx->state[i]);
-
-        /* Zeroize sensitive information. */
-        memset(sctx, 0, sizeof(*sctx));
-
-        return 0;
+        sha256_base_do_finalize(desc, sha256_generic_block_fn);
+        return sha256_base_finish(desc, out);
 }
 
-static int sha224_final(struct shash_desc *desc, u8 *hash)
+int crypto_sha256_finup(struct shash_desc *desc, const u8 *data,
+                        unsigned int len, u8 *hash)
 {
-        u8 D[SHA256_DIGEST_SIZE];
-
-        sha256_final(desc, D);
-
-        memcpy(hash, D, SHA224_DIGEST_SIZE);
-        memzero_explicit(D, SHA256_DIGEST_SIZE);
-
-        return 0;
-}
-
-static int sha256_export(struct shash_desc *desc, void *out)
-{
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-
-        memcpy(out, sctx, sizeof(*sctx));
-        return 0;
-}
-
-static int sha256_import(struct shash_desc *desc, const void *in)
-{
-        struct sha256_state *sctx = shash_desc_ctx(desc);
-
-        memcpy(sctx, in, sizeof(*sctx));
-        return 0;
+        sha256_base_do_update(desc, data, len, sha256_generic_block_fn);
+        return sha256_final(desc, hash);
 }
+EXPORT_SYMBOL(crypto_sha256_finup);
 
 static struct shash_alg sha256_algs[2] = { {
         .digestsize     =       SHA256_DIGEST_SIZE,
-        .init           =       sha256_init,
+        .init           =       sha256_base_init,
         .update         =       crypto_sha256_update,
         .final          =       sha256_final,
-        .export         =       sha256_export,
-        .import         =       sha256_import,
+        .finup          =       crypto_sha256_finup,
         .descsize       =       sizeof(struct sha256_state),
-        .statesize      =       sizeof(struct sha256_state),
         .base           =       {
                 .cra_name       =       "sha256",
                 .cra_driver_name=       "sha256-generic",
@@ -355,9 +261,10 @@ static struct shash_alg sha256_algs[2] = { {
         }
 }, {
         .digestsize     =       SHA224_DIGEST_SIZE,
-        .init           =       sha224_init,
+        .init           =       sha224_base_init,
         .update         =       crypto_sha256_update,
-        .final          =       sha224_final,
+        .final          =       sha256_final,
+        .finup          =       crypto_sha256_finup,
         .descsize       =       sizeof(struct sha256_state),
         .base           =       {
                 .cra_name       =       "sha224",
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index a754cdd749c6..e28c4b5e805d 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -93,6 +93,9 @@ extern int crypto_sha1_finup(struct shash_desc *desc, const u8 *data,
 extern int crypto_sha256_update(struct shash_desc *desc, const u8 *data,
                               unsigned int len);
 
+extern int crypto_sha256_finup(struct shash_desc *desc, const u8 *data,
+                               unsigned int len, u8 *hash);
+
 extern int crypto_sha512_update(struct shash_desc *desc, const u8 *data,
                               unsigned int len);
 #endif