Adds the hashlib.algorithms attribute.  See issue7418.
diff --git a/Doc/library/hashlib.rst b/Doc/library/hashlib.rst
index 4e279de..a7f24d2 100644
--- a/Doc/library/hashlib.rst
+++ b/Doc/library/hashlib.rst
@@ -74,6 +74,15 @@
    >>> h.hexdigest()
    'cc4a5ce1b3df48aec5d22d1f16b894a0b894eccc'
 
+This module provides the following constant attribute:
+
+.. data:: hashlib.algorithms
+
+   A tuple providing the names of the hash algorithms guaranteed to be
+   supported by this module.
+
+   .. versionadded:: 2.7
+
 The following values are provided as constant attributes of the hash objects
 returned by the constructors:
 
diff --git a/Lib/hashlib.py b/Lib/hashlib.py
index 5ecca2b..48f2cfd 100644
--- a/Lib/hashlib.py
+++ b/Lib/hashlib.py
@@ -58,7 +58,9 @@
 # always available algorithm is added.
 __always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')
 
-__all__ = __always_supported + ('new',)
+algorithms = __always_supported
+
+__all__ = __always_supported + ('new', 'algorithms')
 
 
 def __get_builtin_constructor(name):
diff --git a/Lib/test/test_hashlib.py b/Lib/test/test_hashlib.py
index 6ef5557..8710dd6 100644
--- a/Lib/test/test_hashlib.py
+++ b/Lib/test/test_hashlib.py
@@ -102,6 +102,11 @@
             c = cons(a)
             c.hexdigest()
 
+    def test_algorithms_attribute(self):
+        self.assertEqual(hashlib.algorithms,
+            tuple([_algo for _algo in self.supported_hash_names if
+                                                _algo.islower()]))
+
     def test_unknown_hash(self):
         try:
             hashlib.new('spam spam spam spam spam')