To reduce the number of copies of boilerplate code throughout
the tree, this patch implements generic glue for the SHA-1
algorithm. This allows a specific arch or hardware implementation
to only implement the special handling that it needs.
The users need to supply an implementation of
void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks)
and pass it to the SHA-1 base functions. For easy casting between the
prototype above and existing block functions that take a 'u32 state[]'
as their first argument, the 'state' member of struct sha1_state is
moved to the base of the struct.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
include/crypto/sha.h | 2 +-
include/crypto/sha1_base.h | 106 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 107 insertions(+), 1 deletion(-)
create mode 100644 include/crypto/sha1_base.h
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index 190f8a0e0242..a9aad8e63f43 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -65,8 +65,8 @@
#define SHA512_H7 0x5be0cd19137e2179ULL
struct sha1_state {
- u64 count;
u32 state[SHA1_DIGEST_SIZE / 4];
+ u64 count;
u8 buffer[SHA1_BLOCK_SIZE];
};
diff --git a/include/crypto/sha1_base.h b/include/crypto/sha1_base.h
new file mode 100644
index 000000000000..41ccc5f325a0
--- /dev/null
+++ b/include/crypto/sha1_base.h
@@ -0,0 +1,106 @@
+/*
+ * sha1_base.h - core logic for SHA-1 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 (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
+
+static inline int sha1_base_init(struct shash_desc *desc)
+{
+ struct sha1_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA1_H0;
+ sctx->state[1] = SHA1_H1;
+ sctx->state[2] = SHA1_H2;
+ sctx->state[3] = SHA1_H3;
+ sctx->state[4] = SHA1_H4;
+ sctx->count = 0;
+
+ return 0;
+}
+
+static inline int sha1_base_do_update(struct shash_desc *desc,
+ const u8 *data,
+ unsigned int len,
+ sha1_block_fn *block_fn)
+{
+ struct sha1_state *sctx = shash_desc_ctx(desc);
+ unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
+
+ sctx->count += len;
+
+ if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
+ int blocks;
+
+ if (partial) {
+ int p = SHA1_BLOCK_SIZE - partial;
+
+ memcpy(sctx->buffer + partial, data, p);
+ data += p;
+ len -= p;
+
+ block_fn(sctx, sctx->buffer, 1);
+ }
+
+ blocks = len / SHA1_BLOCK_SIZE;
+ len %= SHA1_BLOCK_SIZE;
+
+ if (blocks) {
+ block_fn(sctx, data, blocks);
+ data += blocks * SHA1_BLOCK_SIZE;
+ }
+ partial = 0;
+ }
+ if (len)
+ memcpy(sctx->buffer + partial, data, len);
+
+ return 0;
+}
+
+static inline int sha1_base_do_finalize(struct shash_desc *desc,
+ sha1_block_fn *block_fn)
+{
+ const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
+ struct sha1_state *sctx = shash_desc_ctx(desc);
+ __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
+ unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
+
+ sctx->buffer[partial++] = 0x80;
+ if (partial > bit_offset) {
+ memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
+ partial = 0;
+
+ block_fn(sctx, sctx->buffer, 1);
+ }
+
+ memset(sctx->buffer + partial, 0x0, bit_offset - partial);
+ *bits = cpu_to_be64(sctx->count << 3);
+ block_fn(sctx, sctx->buffer, 1);
+
+ return 0;
+}
+
+static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
+{
+ struct sha1_state *sctx = shash_desc_ctx(desc);
+ __be32 *digest = (__be32 *)out;
+ int i;
+
+ for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
+ put_unaligned_be32(sctx->state[i], digest++);
+
+ *sctx = (struct sha1_state){};
+ return 0;
+}
--
1.8.3.2
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