To reduce the number of copies of boilerplate code throughout
the tree, this patch implements generic glue for the SHA-512
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 (sha512_block_fn)(struct sha512_state *sst, u8 const *src, int blocks)
and pass it to the SHA-512 base functions. For easy casting between the
prototype above and existing block functions that take a 'u64 state[]'
as their first argument, the 'state' member of struct sha512_state is
moved to the base of the struct.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
include/crypto/sha.h | 2 +-
include/crypto/sha512_base.h | 131 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 132 insertions(+), 1 deletion(-)
create mode 100644 include/crypto/sha512_base.h
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index a75bc80cc776..05e82cbc4d8f 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -77,8 +77,8 @@ struct sha256_state {
};
struct sha512_state {
- u64 count[2];
u64 state[SHA512_DIGEST_SIZE / 8];
+ u64 count[2];
u8 buf[SHA512_BLOCK_SIZE];
};
diff --git a/include/crypto/sha512_base.h b/include/crypto/sha512_base.h
new file mode 100644
index 000000000000..6c5341e005ea
--- /dev/null
+++ b/include/crypto/sha512_base.h
@@ -0,0 +1,131 @@
+/*
+ * sha512_base.h - core logic for SHA-512 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 (sha512_block_fn)(struct sha512_state *sst, u8 const *src,
+ int blocks);
+
+static inline int sha384_base_init(struct shash_desc *desc)
+{
+ struct sha512_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA384_H0;
+ sctx->state[1] = SHA384_H1;
+ sctx->state[2] = SHA384_H2;
+ sctx->state[3] = SHA384_H3;
+ sctx->state[4] = SHA384_H4;
+ sctx->state[5] = SHA384_H5;
+ sctx->state[6] = SHA384_H6;
+ sctx->state[7] = SHA384_H7;
+ sctx->count[0] = sctx->count[1] = 0;
+
+ return 0;
+}
+
+static inline int sha512_base_init(struct shash_desc *desc)
+{
+ struct sha512_state *sctx = shash_desc_ctx(desc);
+
+ sctx->state[0] = SHA512_H0;
+ sctx->state[1] = SHA512_H1;
+ sctx->state[2] = SHA512_H2;
+ sctx->state[3] = SHA512_H3;
+ sctx->state[4] = SHA512_H4;
+ sctx->state[5] = SHA512_H5;
+ sctx->state[6] = SHA512_H6;
+ sctx->state[7] = SHA512_H7;
+ sctx->count[0] = sctx->count[1] = 0;
+
+ return 0;
+}
+
+static inline int sha512_base_do_update(struct shash_desc *desc,
+ const u8 *data,
+ unsigned int len,
+ sha512_block_fn *block_fn)
+{
+ struct sha512_state *sctx = shash_desc_ctx(desc);
+ unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
+
+ sctx->count[0] += len;
+ if (sctx->count[0] < len)
+ sctx->count[1]++;
+
+ if (unlikely((partial + len) >= SHA512_BLOCK_SIZE)) {
+ int blocks;
+
+ if (partial) {
+ int p = SHA512_BLOCK_SIZE - partial;
+
+ memcpy(sctx->buf + partial, data, p);
+ data += p;
+ len -= p;
+
+ block_fn(sctx, sctx->buf, 1);
+ }
+
+ blocks = len / SHA512_BLOCK_SIZE;
+ len %= SHA512_BLOCK_SIZE;
+
+ if (blocks) {
+ block_fn(sctx, data, blocks);
+ data += blocks * SHA512_BLOCK_SIZE;
+ }
+ partial = 0;
+ }
+ if (len)
+ memcpy(sctx->buf + partial, data, len);
+
+ return 0;
+}
+
+static inline int sha512_base_do_finalize(struct shash_desc *desc,
+ sha512_block_fn *block_fn)
+{
+ const int bit_offset = SHA512_BLOCK_SIZE - sizeof(__be64[2]);
+ struct sha512_state *sctx = shash_desc_ctx(desc);
+ __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
+ unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
+
+ sctx->buf[partial++] = 0x80;
+ if (partial > bit_offset) {
+ memset(sctx->buf + partial, 0x0, SHA512_BLOCK_SIZE - partial);
+ partial = 0;
+
+ block_fn(sctx, sctx->buf, 1);
+ }
+
+ memset(sctx->buf + partial, 0x0, bit_offset - partial);
+ bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);
+ bits[1] = cpu_to_be64(sctx->count[0] << 3);
+ block_fn(sctx, sctx->buf, 1);
+
+ return 0;
+}
+
+static inline int sha512_base_finish(struct shash_desc *desc, u8 *out)
+{
+ unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
+ struct sha512_state *sctx = shash_desc_ctx(desc);
+ __be64 *digest = (__be64 *)out;
+ int i;
+
+ for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64))
+ put_unaligned_be64(sctx->state[i], digest++);
+
+ *sctx = (struct sha512_state){};
+ return 0;
+}
--
1.8.3.2
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