cleanup: Move modules to "lib/Crypto" subdirectory.

This will avoid the previous situation where scripts like the old "test.py"
get included accidentally in a release.  It also frees us to put additional
build scripts in the top-level directory of the source tree.

5 files changed, 321 insertions, 0 deletions

diff --git a/lib/Crypto/Random/OSRNG/__init__.py b/lib/Crypto/Random/OSRNG/__init__.py
new file mode 100644
index 0000000..c7def0f
--- /dev/null
+++ b/lib/Crypto/Random/OSRNG/__init__.py
@@ -0,0 +1,43 @@
+#
+#  Random/OSRNG/__init__.py : Platform-independent OS RNG API
+#
+# Copyright (C) 2008  Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# =======================================================================
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =======================================================================
+
+"""Provides a platform-independent interface to the random number generators
+supplied by various operating systems."""
+
+__revision__ = "$Id$"
+
+import os
+
+if os.name == 'posix':
+    from Crypto.Random.OSRNG.posix import new
+elif os.name == 'nt':
+    from Crypto.Random.OSRNG.nt import new
+elif hasattr(os, 'urandom'):
+    from Crypto.Random.OSRNG.fallback import new
+else:
+    raise ImportError("Not implemented")
+
+# vim:set ts=4 sw=4 sts=4 expandtab:
diff --git a/lib/Crypto/Random/OSRNG/fallback.py b/lib/Crypto/Random/OSRNG/fallback.py
new file mode 100644
index 0000000..dceaf69
--- /dev/null
+++ b/lib/Crypto/Random/OSRNG/fallback.py
@@ -0,0 +1,48 @@
+#
+#  Random/OSRNG/fallback.py : Fallback entropy source for systems with os.urandom
+#
+# Copyright (C) 2008  Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# =======================================================================
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =======================================================================
+
+__revision__ = "$Id$"
+__all__ = ['PythonOSURandomRNG']
+
+import os
+
+from rng_base import BaseRNG
+
+class PythonOSURandomRNG(BaseRNG):
+
+    name = "<os.urandom>"
+
+    def __init__(self):
+        self._read = os.urandom
+        BaseRNG.__init__(self)
+
+    def _close(self):
+        self._read = None
+
+def new(*args, **kwargs):
+    return PythonOSURandomRNG(*args, **kwargs)
+
+# vim:set ts=4 sw=4 sts=4 expandtab:
diff --git a/lib/Crypto/Random/OSRNG/nt.py b/lib/Crypto/Random/OSRNG/nt.py
new file mode 100644
index 0000000..06f6fec
--- /dev/null
+++ b/lib/Crypto/Random/OSRNG/nt.py
@@ -0,0 +1,76 @@
+#
+#  Random/OSRNG/nt.py : OS entropy source for MS Windows
+#
+# Copyright (C) 2008  Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# =======================================================================
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =======================================================================
+
+__revision__ = "$Id$"
+__all__ = ['WindowsRNG']
+
+import winrandom
+from rng_base import BaseRNG
+
+class WindowsRNG(BaseRNG):
+
+    name = "<CryptGenRandom>"
+
+    def __init__(self):
+        self.__winrand = winrandom.new()
+        BaseRNG.__init__(self)
+
+    def flush(self):
+        """Work around weakness in Windows RNG.
+
+        The CryptGenRandom mechanism in some versions of Windows allows an
+        attacker to learn 128 KiB of past and future output.  As a workaround,
+        this function reads 128 KiB of 'random' data from Windows and discards
+        it.
+
+        For more information about the weaknesses in CryptGenRandom, see
+        _Cryptanalysis of the Random Number Generator of the Windows Operating
+        System_, by Leo Dorrendorf and Zvi Gutterman and Benny Pinkas
+        http://eprint.iacr.org/2007/419
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        data = self.__winrand.get_bytes(128*1024)
+        assert (len(data) == 128*1024)
+        BaseRNG.flush(self)
+
+    def _close(self):
+        self.__winrand = None
+
+    def _read(self, N):
+        # Unfortunately, research shows that CryptGenRandom doesn't provide
+        # forward secrecy and fails the next-bit test unless we apply a
+        # workaround, which we do here.  See http://eprint.iacr.org/2007/419
+        # for information on the vulnerability.
+        self.flush()
+        data = self.__winrand.get_bytes(N)
+        self.flush()
+        return data
+
+def new(*args, **kwargs):
+    return WindowsRNG(*args, **kwargs)
+
+# vim:set ts=4 sw=4 sts=4 expandtab:
diff --git a/lib/Crypto/Random/OSRNG/posix.py b/lib/Crypto/Random/OSRNG/posix.py
new file mode 100644
index 0000000..08d22c8
--- /dev/null
+++ b/lib/Crypto/Random/OSRNG/posix.py
@@ -0,0 +1,65 @@
+#
+#  Random/OSRNG/posix.py : OS entropy source for POSIX systems
+#
+# Copyright (C) 2008  Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# =======================================================================
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =======================================================================
+
+__revision__ = "$Id$"
+__all__ = ['DevURandomRNG']
+
+import os
+import stat
+
+from rng_base import BaseRNG
+
+class DevURandomRNG(BaseRNG):
+
+    def __init__(self, devname=None):
+        if devname is None:
+            self.name = "/dev/urandom"
+        else:
+            self.name = devname
+
+        # Test that /dev/urandom is a character special device
+        f = open(self.name, "rb", 0)
+        fmode = os.fstat(f.fileno())[stat.ST_MODE]
+        if not stat.S_ISCHR(fmode):
+            f.close()
+            raise TypeError("%r is not a character special device" % (self.name,))
+
+        self.__file = f
+        self._read = f.read
+
+        BaseRNG.__init__(self)
+
+    def _close(self):
+        self.__file.close()
+
+    def _read(self, N):
+        return self.__file.read(N)
+
+def new(*args, **kwargs):
+    return DevURandomRNG(*args, **kwargs)
+
+
+# vim:set ts=4 sw=4 sts=4 expandtab:
diff --git a/lib/Crypto/Random/OSRNG/rng_base.py b/lib/Crypto/Random/OSRNG/rng_base.py
new file mode 100644
index 0000000..8e08dc9
--- /dev/null
+++ b/lib/Crypto/Random/OSRNG/rng_base.py
@@ -0,0 +1,89 @@
+#
+#  Random/OSRNG/rng_base.py : Base class for OSRNG
+#
+# Copyright (C) 2008  Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# =======================================================================
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# =======================================================================
+
+__revision__ = "$Id$"
+
+from Crypto.Util.python_compat import *
+
+class BaseRNG(object):
+
+    def __init__(self):
+        self.closed = False
+        self._selftest()
+
+    def __del__(self):
+        self.close()
+
+    def _selftest(self):
+        # Test that urandom can return data
+        data = self.read(16)
+        if len(data) != 16:
+            raise AssertionError("read truncated")
+
+        # Test that we get different data every time (if we don't, the RNG is
+        # probably malfunctioning)
+        data2 = self.read(16)
+        if data == data2:
+            raise AssertionError("OS RNG returned duplicate data")
+
+    # PEP 343: Support for the "with" statement
+    def __enter__(self):
+        pass
+    def __exit__(self):
+        """PEP 343 support"""
+        self.close()
+
+    def close(self):
+        if not self.closed:
+            self._close()
+        self.closed = True
+
+    def flush(self):
+        pass
+
+    def read(self, N=-1):
+        """Return N bytes from the RNG."""
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        if not isinstance(N, (long, int)):
+            raise TypeError("an integer is required")
+        if N < 0:
+            raise ValueError("cannot read to end of infinite stream")
+        elif N == 0:
+            return ""
+        data = self._read(N)
+        if len(data) != N:
+            raise AssertionError("%s produced truncated output (requested %d, got %d)" % (self.name, N, len(data)))
+        return data
+
+    def _close(self):
+        raise NotImplementedError("child class must implement this")
+
+    def _read(self, N):
+        raise NotImplementedError("child class must implement this")
+
+
+# vim:set ts=4 sw=4 sts=4 expandtab: