crypto: fix bug in large buffer handling

Problem reported by Serge Belyshev for glibc in
<http://sourceware.org/bugzilla/show_bug.cgi?id=14090> and for gnulib in
<http://lists.gnu.org/archive/html/bug-gnulib/2012-05/msg00226.html>.
* lib/md4.c (md4_process_block):
* lib/md5.c (md5_process_block):
* lib/sha1.c (sha1_process_block):
* lib/sha256.c (sha256_process_block):
Don't assume the buffer length is less than 2**32.

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/md4.c b/lib/md4.c
index 6307b46bcd..3d1c369ed4 100644
--- a/lib/md4.c
+++ b/lib/md4.c
@@ -301,13 +301,13 @@ md4_process_block (const void *buffer, size_t len, struct md4_ctx *ctx)
   uint32_t B = ctx->B;
   uint32_t C = ctx->C;
   uint32_t D = ctx->D;
+  uint32_t lolen = len;
 
   /* First increment the byte count.  RFC 1320 specifies the possible
      length of the file up to 2^64 bits.  Here we only compute the
      number of bytes.  Do a double word increment.  */
-  ctx->total[0] += len;
-  if (ctx->total[0] < len)
-    ++ctx->total[1];
+  ctx->total[0] += lolen;
+  ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
 
   /* Process all bytes in the buffer with 64 bytes in each round of
      the loop.  */