To reduce the number of copies of boilerplate code throughout
the tree, this patch implements generic glue for the SHA-256
algorithm. This allows a specific arch or hardware implementation
to only implement the special handling that it needs.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
include/crypto/sha256_base.h | 144 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 144 insertions(+)
create mode 100644 include/crypto/sha256_base.h
diff --git a/include/crypto/sha256_base.h b/include/crypto/sha256_base.h
new file mode 100644
index 000000000000..237d549b4093
--- /dev/null
+++ b/include/crypto/sha256_base.h
@@ -0,0 +1,144 @@
+/*
+ * sha256_base.h - core logic for SHA-256 implementations
+ *
+ * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <crypto/internal/hash.h>
+#include <crypto/sha.h>
+#include <linux/crypto.h>
+#include <linux/module.h>
+
+#include <asm/unaligned.h>
+
+typedef void (sha256_block_fn)(int blocks, u8 const *src, u32 *state,
+ const u8 *head, void *p);
+
+static inline int sha224_base_init(struct shash_desc *desc)
+{
+ 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 inline int sha256_base_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;
+}
+
+static inline int sha256_base_export(struct shash_desc *desc, void *out)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ struct sha256_state *dst = out;
+
+ *dst = *sctx;
+
+ return 0;
+}
+
+static inline int sha256_base_import(struct shash_desc *desc, const void *in)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ struct sha256_state const *src = in;
+
+ *sctx = *src;
+
+ return 0;
+}
+
+static inline int sha256_base_do_update(struct shash_desc *desc, const u8 *data,
+ unsigned int len,
+ sha256_block_fn *block_fn, void *p)
+{
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
+
+ sctx->count += len;
+
+ if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
+ int blocks;
+
+ if (partial) {
+ int p = SHA256_BLOCK_SIZE - partial;
+
+ memcpy(sctx->buf + partial, data, p);
+ data += p;
+ len -= p;
+ }
+
+ blocks = len / SHA256_BLOCK_SIZE;
+ len %= SHA256_BLOCK_SIZE;
+
+ block_fn(blocks, data, sctx->state,
+ partial ? sctx->buf : NULL, p);
+ data += blocks * SHA256_BLOCK_SIZE;
+ partial = 0;
+ }
+ if (len)
+ memcpy(sctx->buf + partial, data, len);
+
+ return 0;
+}
+
+static inline int sha256_base_do_finalize(struct shash_desc *desc,
+ sha256_block_fn *block_fn, void *p)
+{
+ const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
+ unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
+
+ sctx->buf[partial++] = 0x80;
+ if (partial > bit_offset) {
+ memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
+ partial = 0;
+
+ block_fn(1, sctx->buf, sctx->state, NULL, p);
+ }
+
+ memset(sctx->buf + partial, 0x0, bit_offset - partial);
+ *bits = cpu_to_be64(sctx->count << 3);
+ block_fn(1, sctx->buf, sctx->state, NULL, p);
+
+ return 0;
+}
+
+static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
+{
+ unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
+ struct sha256_state *sctx = shash_desc_ctx(desc);
+ __be32 *digest = (__be32 *)out;
+ int i;
+
+ for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
+ put_unaligned_be32(sctx->state[i], digest++);
+
+ *sctx = (struct sha256_state){};
+ return 0;
+}
--
1.8.3.2
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