Add google-endpoints to third_party/.

third_party/google-endpoints/Crypto/Random/OSRNG/posix.py

+#
+#  Random/OSRNG/posix.py : OS entropy source for POSIX systems
+#
+# Written in 2008 by Dwayne C. Litzenberger <dlitz@dlitz.net>
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain.  To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+
+__revision__ = "$Id$"
+__all__ = ['DevURandomRNG']
+
+import errno
+import os
+import stat
+
+from rng_base import BaseRNG
+from Crypto.Util.py3compat import b
+
+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
+
+        BaseRNG.__init__(self)
+
+    def _close(self):
+        self.__file.close()
+
+    def _read(self, N):
+        # Starting with Python 3 open with buffering=0 returns a FileIO object.
+        # FileIO.read behaves like read(2) and not like fread(3) and thus we
+        # have to handle the case that read returns less data as requested here
+        # more carefully.
+        data = b("")
+        while len(data) < N:
+            try:
+                d = self.__file.read(N - len(data))
+            except IOError, e:
+                # read(2) has been interrupted by a signal; redo the read
+                if e.errno == errno.EINTR:
+                    continue
+                raise
+
+            if d is None:
+                # __file is in non-blocking mode and no data is available
+                return data
+            if len(d) == 0:
+                # __file is in blocking mode and arrived at EOF
+                return data
+
+            data += d
+        return data
+
+def new(*args, **kwargs):
+    return DevURandomRNG(*args, **kwargs)
+
+
+# vim:set ts=4 sw=4 sts=4 expandtab: