diff -r 9fdeca5fdbf0 Doc/library/hashlib.rst
--- a/Doc/library/hashlib.rst	Mon Mar 28 06:13:52 2016 +0000
+++ b/Doc/library/hashlib.rst	Wed Mar 30 15:45:54 2016 +0300
@@ -176,6 +176,29 @@
    compute the digests of data sharing a common initial substring.
 
 
+.. _hashlib-commandline:
+
+Command Line Interface
+----------------------
+
+.. versionadded:: 3.6
+
+:mod:`hashlib` can also be invoked directly using the :option:`-m` switch of
+the interpreter with a ``algorithm`` argument. Available algorithms
+are :func:`md5`, :func:`sha1`, :func:`sha224`, :func:`sha256`, :func:`sha384`,
+and :func:`sha512`. Additional algorithms may also be available depending upon
+the OpenSSL library that Python uses on your platform.
+
+When a ``file`` argument is given the hash is calculated on the file::
+
+    $ python -m hashlib md5 /bin/sh
+    $ d985d0ea551c1253c2305140c583d11f
+
+With no ``file``, or when ``file`` is -, read standard input::
+
+    $ cat /bin/sh | python -m hashlib md5
+    $ d985d0ea551c1253c2305140c583d11f
+
 Key derivation
 --------------
 
diff -r 9fdeca5fdbf0 Lib/hashlib.py
--- a/Lib/hashlib.py	Mon Mar 28 06:13:52 2016 +0000
+++ b/Lib/hashlib.py	Wed Mar 30 15:45:54 2016 +0300
@@ -1,3 +1,4 @@
+#! /usr/bin/env python3
 #.  Copyright (C) 2005-2010   Gregory P. Smith (greg@krypto.org)
 #  Licensed to PSF under a Contributor Agreement.
 #
@@ -215,3 +216,30 @@
 # Cleanup locals()
 del __always_supported, __func_name, __get_hash
 del __py_new, __hash_new, __get_openssl_constructor
+
+
+# Usable as a script...
+def main():
+    import argparse
+    import sys
+    import os
+    parser = argparse.ArgumentParser()
+    parser.add_argument('algorithm', action='store',
+                        choices=algorithms_available,
+                        help='Specify algorithm to use for hash calculation.')
+    parser.add_argument('file', metavar='FILE', type=argparse.FileType("rb"),
+                        default=sys.stdin.buffer, nargs='?',
+                        help='Calculate hash on given file. With no FILE, or when FILE is -, read standard input.')
+    args = parser.parse_args()
+    hash_obj = new(args.algorithm)
+    block_size = os.stat(args.file.fileno()).st_blksize
+    while True:
+        data = args.file.read(block_size)
+        hash_obj.update(data)
+        if len(data) < block_size:
+            break
+    print(hash_obj.hexdigest())
+
+
+if __name__ == '__main__':
+    main()
diff -r 9fdeca5fdbf0 Lib/test/test_hashlib.py
--- a/Lib/test/test_hashlib.py	Mon Mar 28 06:13:52 2016 +0000
+++ b/Lib/test/test_hashlib.py	Wed Mar 30 15:45:54 2016 +0300
@@ -18,7 +18,7 @@
 import unittest
 import warnings
 from test import support
-from test.support import _4G, bigmemtest, import_fresh_module
+from test.support import _4G, bigmemtest, import_fresh_module, script_helper
 
 # Were we compiled --with-pydebug or with #define Py_DEBUG?
 COMPILED_WITH_PYDEBUG = hasattr(sys, 'gettotalrefcount')
@@ -526,5 +526,36 @@
         self._test_pbkdf2_hmac(c_hashlib.pbkdf2_hmac)
 
 
+class TestMain(unittest.TestCase):
+    supported_algorithms = hashlib.algorithms_available
+    data = b"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
+
+    def setUp(self):
+        with open(support.TESTFN, 'wb') as fp:
+            fp.write(self.data)
+
+    def tearDown(self):
+        if os.path.exists(support.TESTFN):
+            os.unlink(support.TESTFN)
+
+    def get_output(self, *args):
+        return script_helper.assert_python_ok('-m', 'hashlib', *args).out.rstrip()
+
+    def expected_output(self, algorithm):
+        return hashlib.new(algorithm, self.data).hexdigest().encode("ascii")
+
+    def test_calculate_file_hash(self):
+        for algorithm in self.supported_algorithms:
+            output = self.get_output(algorithm, support.TESTFN)
+            self.assertEqual(output, self.expected_output(algorithm))
+
+    def test_calculate_hash_from_stdin(self):
+        for algorithm in self.supported_algorithms:
+            with script_helper.spawn_python('-m', 'hashlib', algorithm) as proc:
+                out, err = proc.communicate(self.data)
+            self.assertEqual(out.rstrip(), self.expected_output(algorithm))
+            self.assertIsNone(err)
+
+
 if __name__ == "__main__":
     unittest.main()