catacomb/__init__.py (_HashBase): Check that integers are within bounds.

[catacomb-python] / catacomb / __init__.py

diff --git a/catacomb/__init__.py b/catacomb/__init__.py
index ff771b9..24265ac 100644 (file)
--- a/catacomb/__init__.py
+++ b/catacomb/__init__.py
@@ -206,15 +206,31 @@ _augment(Poly1305Hash, _tmp)
 class _HashBase (object):
   ## The standard hash methods.  Assume that `hash' is defined and returns
   ## the receiver.
-  def hashu8(me, n): return me.hash(_pack('B', n))
-  def hashu16l(me, n): return me.hash(_pack('<H', n))
-  def hashu16b(me, n): return me.hash(_pack('>H', n))
+  def _check_range(me, n, max):
+    if not (0 <= n <= max): raise OverflowError("out of range")
+  def hashu8(me, n):
+    me._check_range(n, 0xff)
+    return me.hash(_pack('B', n))
+  def hashu16l(me, n):
+    me._check_range(n, 0xffff)
+    return me.hash(_pack('<H', n))
+  def hashu16b(me, n):
+    me._check_range(n, 0xffff)
+    return me.hash(_pack('>H', n))
   hashu16 = hashu16b
-  def hashu32l(me, n): return me.hash(_pack('<L', n))
-  def hashu32b(me, n): return me.hash(_pack('>L', n))
+  def hashu32l(me, n):
+    me._check_range(n, 0xffffffff)
+    return me.hash(_pack('<L', n))
+  def hashu32b(me, n):
+    me._check_range(n, 0xffffffff)
+    return me.hash(_pack('>L', n))
   hashu32 = hashu32b
-  def hashu64l(me, n): return me.hash(_pack('<Q', n))
-  def hashu64b(me, n): return me.hash(_pack('>Q', n))
+  def hashu64l(me, n):
+    me._check_range(n, 0xffffffffffffffff)
+    return me.hash(_pack('<Q', n))
+  def hashu64b(me, n):
+    me._check_range(n, 0xffffffffffffffff)
+    return me.hash(_pack('>Q', n))
   hashu64 = hashu64b
   def hashbuf8(me, s): return me.hashu8(len(s)).hash(s)
   def hashbuf16l(me, s): return me.hashu16l(len(s)).hash(s)
@@ -237,7 +253,7 @@ class _ShakeBase (_HashBase):
     me._h = me._SHAKE(perso = perso, func = me._FUNC)
 
   ## Delegate methods...
-  def copy(me): new = me.__class__(); new._copy(me)
+  def copy(me): new = me.__class__._bare_new(); new._copy(me); return new
   def _copy(me, other): me._h = other._h.copy()
   def hash(me, m): me._h.hash(m); return me
   def xof(me): me._h.xof(); return me
@@ -251,6 +267,8 @@ class _ShakeBase (_HashBase):
   def buffered(me): return me._h.buffered
   @property
   def rate(me): return me._h.rate
+  @classmethod
+  def _bare_new(cls): return cls()
 
 class _tmp:
   def check(me, h):
@@ -289,6 +307,8 @@ class KMAC (_ShakeBase):
   def xof(me):
     me.rightenc(0)
     return super(KMAC, me).xof()
+  @classmethod
+  def _bare_new(cls): return cls("")
 
 class KMAC128 (KMAC): _SHAKE = Shake128; _TAGSZ = 16
 class KMAC256 (KMAC): _SHAKE = Shake256; _TAGSZ = 32