Use hash transform function return type for passing burn stack depth

* cipher/gostr4311-94.c (transform): Return stack burn depth.
* cipher/hash-common.c (_gcry_md_block_write): Use stack burn depth
returned by 'hd->bwrite'.
* cipher/hash-common.h (_gcry_md_block_write_t): Change return type to
'unsigned int'.
(gry_md_block_ctx_t): Remove 'stack_burn'.
* cipher/md4.c (transform): Return stack burn depth.
(md4_final): Use stack burn depth from transform.
* cipher/md5.c (transform): Return stack burn depth.
(md5_final): Use stack burn depth from transform.
* cipher/rmd160.c (transform): Return stack burn depth.
(rmd160_final): Use stack burn depth from transform.
* cipher/sha1.c (transform): Return stack burn depth.
(sha1_final): Use stack burn depth from transform.
* cipher/sha256.c (transform): Return stack burn depth.
(sha256_final): Use stack burn depth from transform.
* cipher/sha512.c (__transform, transform): Return stack burn depth.
(sha512_final): Use stack burn depth from transform.
* cipher/stribog.c (transform64): Return stack burn depth.
* cipher/tiger.c (transform): Return stack burn depth.
(tiger_final): Use stack burn depth from transform.
--

Transform function might want different depth of stack burn depending on
detected CPU features (like in SHA-512 on ARM with NEON). So return
stack burn depth from transform functions as a request or a hint to
calling function.

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

1 files changed, 6 insertions, 4 deletions

diff --git a/cipher/hash-common.c b/cipher/hash-common.c
index 1a6e8e9f..e318e7e1 100644
--- a/cipher/hash-common.c
+++ b/cipher/hash-common.c
@@ -101,6 +101,7 @@ _gcry_md_block_write (void *context, const void *inbuf_arg, size_t inlen)
 {
   const unsigned char *inbuf = inbuf_arg;
   gcry_md_block_ctx_t *hd = context;
+  unsigned int stack_burn = 0;
 
   if (sizeof(hd->buf) < hd->blocksize)
     BUG();
@@ -110,8 +111,9 @@ _gcry_md_block_write (void *context, const void *inbuf_arg, size_t inlen)
 
   if (hd->count == hd->blocksize)  /* Flush the buffer. */
     {
-      hd->bwrite (hd, hd->buf);
-      _gcry_burn_stack (hd->stack_burn);
+      stack_burn = hd->bwrite (hd, hd->buf);
+      _gcry_burn_stack (stack_burn);
+      stack_burn = 0;
       hd->count = 0;
       hd->nblocks++;
     }
@@ -129,13 +131,13 @@ _gcry_md_block_write (void *context, const void *inbuf_arg, size_t inlen)
 
   while (inlen >= hd->blocksize)
     {
-      hd->bwrite (hd, inbuf);
+      stack_burn = hd->bwrite (hd, inbuf);
       hd->count = 0;
       hd->nblocks++;
       inlen -= hd->blocksize;
       inbuf += hd->blocksize;
     }
-  _gcry_burn_stack (hd->stack_burn);
+  _gcry_burn_stack (stack_burn);
   for (; inlen && hd->count < hd->blocksize; inlen--)
     hd->buf[hd->count++] = *inbuf++;
 }