Fix #2: Import escape_attribute_value from upstream

2 files changed, 102 insertions, 2 deletions

diff --git a/radicale_auth_ldap/__init__.py b/radicale_auth_ldap/__init__.py
index d04c43b..5ef2b13 100644
--- a/radicale_auth_ldap/__init__.py
+++ b/radicale_auth_ldap/__init__.py
@@ -25,12 +25,15 @@ Authentication based on the ``ldap3`` module
 (https://github.com/cannatag/ldap3/).
 """
 
+
 import ldap3
 import ldap3.core.exceptions
-import ldap3.utils.dn
 
 from radicale.auth import BaseAuth
 
+import radicale_auth_ldap.ldap3imports
+
+
 class Auth(BaseAuth):
     def is_authenticated(self, user, password):
         """Check if ``user``/``password`` couple is valid."""
@@ -53,7 +56,7 @@ class Auth(BaseAuth):
         except Exception as err:
             self.logger.debug("LDAP error: %s" % err)
 
-        distinguished_name = "%s=%s" % (ATTRIBUTE, ldap3.utils.dn.escape_attribute_value(user))
+        distinguished_name = "%s=%s" % (ATTRIBUTE, ldap3imports.escape_attribute_value(user))
         self.logger.debug("LDAP bind for %s in base %s" % (distinguished_name, BASE))
 
         if FILTER:
diff --git a/radicale_auth_ldap/ldap3imports.py b/radicale_auth_ldap/ldap3imports.py
new file mode 100644
index 0000000..840ff21
--- /dev/null
+++ b/radicale_auth_ldap/ldap3imports.py
@@ -0,0 +1,97 @@
+# -*- coding: utf-8 -*-
+
+"""
+This code was imported from ldap3, because upstream obviously deprecated this.
+Until I come around finding a better solution, this will stay here.
+All this code was written by people from the ldap3 project and keeps the original license, of course.
+
+Original header below:
+
+# Created on 2014.09.08
+#
+# Author: Giovanni Cannata
+#
+# Copyright 2014, 2015, 2016 Giovanni Cannata
+#
+# This file is part of ldap3.
+#
+# ldap3 is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# ldap3 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with ldap3 in the COPYING and COPYING.LESSER files.
+# If not, see <http://www.gnu.org/licenses/>.
+"""
+from string import hexdigits
+
+STATE_ANY = 0
+STATE_ESCAPE = 1
+STATE_ESCAPE_HEX = 2
+
+
+def escape_attribute_value(attribute_value):
+    if not attribute_value:
+        return ''
+
+    if attribute_value[0] == '#':  # with leading SHARP only pairs of hex characters are valid
+        valid_hex = True
+        if len(attribute_value) % 2 == 0:  # string must be # + HEX HEX (an odd number of chars)
+            valid_hex = False
+
+        if valid_hex:
+            for c in attribute_value:
+                if c not in hexdigits:  # allowed only hex digits as per RFC 4514
+                    valid_hex = False
+                    break
+
+        if valid_hex:
+            return attribute_value
+
+    state = STATE_ANY
+    escaped = ''
+    tmp_buffer = ''
+    for c in attribute_value:
+        if state == STATE_ANY:
+            if c == '\\':
+                state = STATE_ESCAPE
+            elif c in '"#+,;<=>\00':
+                escaped += '\\' + c
+            else:
+                escaped += c
+        elif state == STATE_ESCAPE:
+            if c in hexdigits:
+                tmp_buffer = c
+                state = STATE_ESCAPE_HEX
+            elif c in ' "#+,;<=>\\\00':
+                escaped += '\\' + c
+                state = STATE_ANY
+            else:
+                escaped += '\\\\' + c
+        elif state == STATE_ESCAPE_HEX:
+            if c in hexdigits:
+                escaped += '\\' + tmp_buffer + c
+            else:
+                escaped += '\\\\' + tmp_buffer + c
+            tmp_buffer = ''
+            state = STATE_ANY
+
+    # final state
+    if state == STATE_ESCAPE:
+        escaped += '\\\\'
+    elif state == STATE_ESCAPE_HEX:
+        escaped += '\\\\' + tmp_buffer
+
+    if escaped[0] == ' ':  # leading SPACE must be escaped
+        escaped = '\\' + escaped
+
+    if escaped[-1] == ' ' and len(escaped) > 1 and escaped[-2] != '\\':  # trailing SPACE must be escaped
+        escaped = escaped[:-1] + '\\ '
+
+    return escaped