1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/dnspython/dns/hash.py b/third_party/dnspython/dns/hash.py
new file mode 100644
index 0000000000..0c708036b1
--- /dev/null
+++ b/third_party/dnspython/dns/hash.py
@@ -0,0 +1,67 @@
+# Copyright (C) 2011 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""Hashing backwards compatibility wrapper"""
+
+import sys
+
+_hashes = None
+
+def _need_later_python(alg):
+    def func(*args, **kwargs):
+        raise NotImplementedError("TSIG algorithm " + alg +
+                                  " requires Python 2.5.2 or later")
+    return func
+
+def _setup():
+    global _hashes
+    _hashes = {}
+    try:
+        import hashlib
+        _hashes['MD5'] = hashlib.md5
+        _hashes['SHA1'] = hashlib.sha1
+        _hashes['SHA224'] = hashlib.sha224
+        _hashes['SHA256'] = hashlib.sha256
+        if sys.hexversion >= 0x02050200:
+            _hashes['SHA384'] = hashlib.sha384
+            _hashes['SHA512'] = hashlib.sha512
+        else:
+            _hashes['SHA384'] = _need_later_python('SHA384')
+            _hashes['SHA512'] = _need_later_python('SHA512')
+
+        if sys.hexversion < 0x02050000:
+            # hashlib doesn't conform to PEP 247: API for
+            # Cryptographic Hash Functions, which hmac before python
+            # 2.5 requires, so add the necessary items.
+            class HashlibWrapper:
+                def __init__(self, basehash):
+                    self.basehash = basehash
+                    self.digest_size = self.basehash().digest_size
+
+                def new(self, *args, **kwargs):
+                    return self.basehash(*args, **kwargs)
+
+            for name in _hashes:
+                _hashes[name] = HashlibWrapper(_hashes[name])
+
+    except ImportError:
+        import md5, sha
+        _hashes['MD5'] =  md5
+        _hashes['SHA1'] = sha
+
+def get(algorithm):
+    if _hashes is None:
+        _setup()
+    return _hashes[algorithm.upper()]