symm/cbc-def.h: Fix discarding output for short inputs.

[catacomb] / symm / hash.h

diff --git a/symm/hash.h b/symm/hash.h
index dc9ad02..420277d 100644 (file)
--- a/symm/hash.h
+++ b/symm/hash.h
@@ -59,6 +59,8 @@
   pre##_ctx *_bctx = (ictx);                                           \
   size_t _bsz = (isz);                                                 \
   const octet *_bbuf = (octet *)(ibuf);                                        \
+  size_t _s;                                                           \
+  uint32 _l, _h;                                                       \
                                                                        \
   /* --- Add on the size done so far --- *                             \
    *                                                                   \
@@ -66,29 +68,23 @@
    * how many bits you've actually got.                                        \
    */                                                                  \
                                                                        \
-  {                                                                    \
-    uint32 _l = U32(_bsz);                                             \
-    uint32 _h = ((_bsz & ~MASK32) >> 16) >> 16;                                \
-    _bctx->nh += _h;                                                   \
-    _bctx->nl += _l;                                                   \
-    if (_bctx->nl < _l || _bctx->nl & ~MASK32)                         \
-      _bctx->nh++;                                                     \
-  }                                                                    \
+  _l = U32(_bsz); _h = ((_bsz & ~(size_t)MASK32) >> 16) >> 16;         \
+  _bctx->nl += _l; if (_bctx->nl < _l || _bctx->nl & ~(uint32)MASK32) _h++; \
+  _bctx->nh += _h;                                                     \
                                                                        \
   /* --- Handle very small contributions --- */                                \
                                                                        \
-  if (_bctx->off + _bsz < PRE##_BUFSZ) {                               \
-    memcpy(_bctx->buf + _bctx->off, _bbuf, _bsz);                      \
-    _bctx->off += _bsz;                                                        \
-  } else {                                                             \
+  if (_bctx->off + _bsz < PRE##_BUFSZ)                                 \
+    { memcpy(_bctx->buf + _bctx->off, _bbuf, _bsz); _bctx->off += _bsz; } \
+  else {                                                               \
                                                                        \
     /* --- Handle an initial partial buffer --- */                     \
                                                                        \
     if (_bctx->off) {                                                  \
-      size_t s = PRE##_BUFSZ - _bctx->off;                             \
-      memcpy(_bctx->buf + _bctx->off, _bbuf, s);                       \
+      _s = PRE##_BUFSZ - _bctx->off;                                   \
+      memcpy(_bctx->buf + _bctx->off, _bbuf, _s);                      \
       pre##_compress(_bctx, _bctx->buf);                               \
-      _bsz -= s; _bbuf += s;                                           \
+      _bsz -= _s; _bbuf += _s;                                         \
     }                                                                  \
                                                                        \
     /* --- Do whole buffers while we can --- */                                \
@@ -100,8 +96,7 @@
                                                                        \
     /* --- And wrap up at the end --- */                               \
                                                                        \
-    if (_bsz)                                                          \
-      memcpy(_bctx->buf, _bbuf, _bsz);                                 \
+    if (_bsz) memcpy(_bctx->buf, _bbuf, _bsz);                         \
     _bctx->off = _bsz;                                                 \
   }                                                                    \
 } while (0)