Make SHA-512 use the new _gcry_md_block_write helper

* cipher/hash-common.c (_gcry_md_block_write): Check that hd->buf is
large enough.
* cipher/hash-common.h (MD_BLOCK_MAX_BLOCKSIZE, MD_NBLOCKS_TYPE): New
macros.
(gcry_md_block_ctx_t): Use above macros for 'nblocks' and 'buf'.
* cipher/sha512.c (SHA512_STATE): New struct.
(SHA512_CONTEXT): Add 'bctx' and 'state'.
(sha512_init, sha384_init): Initialize 'bctx'.
(__transform, _gcry_sha512_transform_armv7_neon): Use SHA512_STATE for
'hd'.
(transform): For now, do not return burn stack.
(sha512_write): Remove.
(sha512_final): Use _gcry_md_block_write and bctx.
(_gcry_digest_spec_sha512, _gcry_digest_spec_sha384): Use
_gcry_md_block_write.
--

Patch changes 'nblocks' counter to 64-bits when SHA-512 is enabled. This does
not cause problems with other algorithms; they are already casting 'nblocks'
to u32 variable in their finalization functions. Also move 'buf' member to
head of 'gcry_md_block_ctx_t' to ensure proper alignment; this is because some
algorithms cast buffer pointer to (u64*) in final endian conversion.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

1 files changed, 14 insertions, 3 deletions

diff --git a/cipher/hash-common.h b/cipher/hash-common.h
index 1d1d4ec5..4dd54411 100644
--- a/cipher/hash-common.h
+++ b/cipher/hash-common.h
@@ -20,6 +20,8 @@
 #ifndef GCRY_HASH_COMMON_H
 #define GCRY_HASH_COMMON_H
 
+#include "types.h"
+
 
 const char * _gcry_hash_selftest_check_one
 /**/         (int algo,
@@ -29,11 +31,20 @@ const char * _gcry_hash_selftest_check_one
 /* Type for the md_write helper function.  */
 typedef void (*_gcry_md_block_write_t) (void *c, const unsigned char *buf);
 
+#if defined(HAVE_U64_TYPEDEF) && defined(USE_SHA512)
+/* SHA-512 needs u64 and larger buffer. */
+# define MD_BLOCK_MAX_BLOCKSIZE 128
+# define MD_NBLOCKS_TYPE u64
+#else
+# define MD_BLOCK_MAX_BLOCKSIZE 64
+# define MD_NBLOCKS_TYPE u32
+#endif
+
 typedef struct gcry_md_block_ctx
 {
-    u32  nblocks;
-    int  count;
-    byte buf[64];
+    byte buf[MD_BLOCK_MAX_BLOCKSIZE];
+    MD_NBLOCKS_TYPE nblocks;
+    int count;
     size_t blocksize;
     _gcry_md_block_write_t bwrite;
     size_t stack_burn;