plugin XEP-0300: hashes management first draft

src/plugins/plugin_xep_0300.py

@@ -0,0 +1,63 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# SAT plugin for Hash functions (XEP-0300)
+# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from sat.core.i18n import _
+from sat.core.log import getLogger
+log = getLogger(__name__)
+from twisted.words.xish import domish
+import hashlib
+
+
+NS_HASHES = "urn:xmpp:hashes:1"
+
+PLUGIN_INFO = {
+    "name": "Cryptographic Hash Functions",
+    "import_name": "XEP-0300",
+    "type": "XEP",
+    "protocols": ["XEP-0300"],
+    "main": "XEP_0300",
+    "handler": "no",
+    "description": _("""Management of cryptographic hashes""")
+}
+
+
+class XEP_0300(object):
+    ALGOS = {u'md5': hashlib.md5,
+             u'sha-1': hashlib.sha1,
+             u'sha-256': hashlib.sha256,
+             u'sha-512': hashlib.sha512,
+            }
+
+    def __init__(self, host):
+        log.info(_("plugin Hashes initialization"))
+
+    def buidHash(self, file_obj=None, algo='sha-256'):
+        """Compute hash and build hash element
+
+        @param file_obj(file, None): file to use to calculate the hash
+            if file_obj is None, en empty hash element will be returned (useful e.g. in XEP-0234)
+        @param algo(unicode): algorithme to use, must be a key of XEP_0300.ALGOS
+        @return (domish.Element): computed hash
+        """
+        hasher = self.ALGOS[algo]
+        hash_elt = domish.Element((NS_HASHES, 'hash'))
+        hash_elt['algo']=algo
+        # TODO: actually hash, use deferToThread
+        return hash_elt
+