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.

Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
---
 crypto/Kconfig          |   1 +
 crypto/sha256_generic.c | 139 ++++++++++--------------------------------------
 include/crypto/sha.h    |   3 ++
 3 files changed, 31 insertions(+), 112 deletions(-)

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 83bc1680391a..72bf5af7240d 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -611,6 +611,7 @@ config CRYPTO_SHA256_BASE
 
 config CRYPTO_SHA256
        tristate "SHA224 and SHA256 digest algorithm"
+       select CRYPTO_SHA256_BASE
        select CRYPTO_HASH
        help
          SHA256 secure hash standard (DFIPS 180-2).
diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c
index b001ff5c2efc..d5c18c08b3da 100644
--- a/crypto/sha256_generic.c
+++ b/crypto/sha256_generic.c
@@ -214,136 +214,50 @@ 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(int blocks, u8 const *src, u32 *state,
+                                   const u8 *head, void *p)
 {
-       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;
+       if (head)
+               sha256_transform(state, head);
 
-       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(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 crypto_sha256_base_do_update(desc, data, len,
+                                           sha256_generic_block_fn, NULL);
 }
 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;
-}
-
-static int sha224_final(struct shash_desc *desc, 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)
+int crypto_sha256_finup(struct shash_desc *desc, const u8 *data,
+                       unsigned int len, u8 *hash)
 {
-       struct sha256_state *sctx = shash_desc_ctx(desc);
-
-       memcpy(out, sctx, sizeof(*sctx));
-       return 0;
+       if (len)
+               crypto_sha256_base_do_update(desc, data, len,
+                                            sha256_generic_block_fn, NULL);
+       crypto_sha256_base_do_finalize(desc, sha256_generic_block_fn, NULL);
+       return crypto_sha256_base_finish(desc, hash);
 }
+EXPORT_SYMBOL(crypto_sha256_finup);
 
-static int sha256_import(struct shash_desc *desc, const void *in)
+static int sha256_final(struct shash_desc *desc, u8 *out)
 {
-       struct sha256_state *sctx = shash_desc_ctx(desc);
-
-       memcpy(sctx, in, sizeof(*sctx));
-       return 0;
+       return crypto_sha256_finup(desc, NULL, 0, out);
 }
 
 static struct shash_alg sha256_algs[2] = { {
        .digestsize     =       SHA256_DIGEST_SIZE,
-       .init           =       sha256_init,
+       .init           =       crypto_sha256_base_init,
        .update         =       crypto_sha256_update,
        .final          =       sha256_final,
-       .export         =       sha256_export,
-       .import         =       sha256_import,
+       .finup          =       crypto_sha256_finup,
+       .export         =       crypto_sha256_base_export,
+       .import         =       crypto_sha256_base_import,
        .descsize       =       sizeof(struct sha256_state),
        .statesize      =       sizeof(struct sha256_state),
        .base           =       {
@@ -355,9 +269,10 @@ static struct shash_alg sha256_algs[2] = { {
        }
 }, {
        .digestsize     =       SHA224_DIGEST_SIZE,
-       .init           =       sha224_init,
+       .init           =       crypto_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 17a1c43b2a01..1b4d9a87c2a4 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -97,6 +97,9 @@ extern int crypto_sha1_update(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);
 
-- 
1.8.3.2

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