From: Sergey Matveev <stargrave@stargrave.org>
Date: Thu, 23 Jan 2020 15:59:49 +0000 (+0300)
Subject: PrintableString can optionally allow * and &
X-Git-Tag: 5.6^0
X-Git-Url: http://www.git.cypherpunks.ru/?p=pyderasn.git;a=commitdiff_plain;h=de2299f02a411f3b805058afa84118cf361c99c8

PrintableString can optionally allow * and &
---

diff --git a/doc/news.rst b/doc/news.rst
index fe3a293..4baa462 100644
--- a/doc/news.rst
+++ b/doc/news.rst
@@ -8,6 +8,10 @@ News
 * Convenient ``.decod()`` method, that raises if tail is not empty
 * Control characters (like newlines) of text fields in pprinted output
   are escaped
+* Ability to allow asterisk and ampersand characters
+  (``allow_asterisk``, ``allow_ampersand`` kwargs) in
+  ``PrintableString``, that unfortunately could be met
+  in X.509 certificates
 
 .. _release5.5:
 
diff --git a/pyderasn.py b/pyderasn.py
index 2972db7..f4f38a2 100755
--- a/pyderasn.py
+++ b/pyderasn.py
@@ -570,6 +570,7 @@ _____________
 PrintableString
 _______________
 .. autoclass:: pyderasn.PrintableString
+   :members: __init__
 
 UTCTime
 _______
@@ -3779,6 +3780,32 @@ class PrintableString(AllowableCharsMixin, CommonString):
     _allowable_chars = frozenset(
         (ascii_letters + digits + " '()+,-./:=?").encode("ascii")
     )
+    _asterisk = frozenset("*".encode("ascii"))
+    _ampersand = frozenset("&".encode("ascii"))
+
+    def __init__(
+            self,
+            value=None,
+            bounds=None,
+            impl=None,
+            expl=None,
+            default=None,
+            optional=False,
+            _decoded=(0, 0, 0),
+            allow_asterisk=False,
+            allow_ampersand=False,
+    ):
+        """
+        :param allow_asterisk: allow asterisk character
+        :param allow_ampersand: allow ampersand character
+        """
+        if allow_asterisk:
+            self._allowable_chars |= self._asterisk
+        if allow_ampersand:
+            self._allowable_chars |= self._ampersand
+        super(PrintableString, self).__init__(
+            value, bounds, impl, expl, default, optional, _decoded,
+        )
 
     def _value_sanitize(self, value):
         value = super(PrintableString, self)._value_sanitize(value)
@@ -3786,6 +3813,34 @@ class PrintableString(AllowableCharsMixin, CommonString):
             raise DecodeError("non-printable value")
         return value
 
+    def copy(self):
+        obj = super(PrintableString, self).copy()
+        obj._allowable_chars = self._allowable_chars
+        return obj
+
+    def __call__(
+            self,
+            value=None,
+            bounds=None,
+            impl=None,
+            expl=None,
+            default=None,
+            optional=None,
+    ):
+        return self.__class__(
+            value=value,
+            bounds=(
+                (self._bound_min, self._bound_max)
+                if bounds is None else bounds
+            ),
+            impl=self.tag if impl is None else impl,
+            expl=self._expl if expl is None else expl,
+            default=self.default if default is None else default,
+            optional=self.optional if optional is None else optional,
+            allow_asterisk=self._asterisk <= self._allowable_chars,
+            allow_ampersand=self._ampersand <= self._allowable_chars,
+        )
+
 
 class TeletexString(CommonString):
     __slots__ = ()
diff --git a/tests/test_pyderasn.py b/tests/test_pyderasn.py
index 9fbb33e..aaac6cd 100644
--- a/tests/test_pyderasn.py
+++ b/tests/test_pyderasn.py
@@ -3506,6 +3506,21 @@ class TestPrintableString(
         self.assertEqual(err.exception.offset, offset)
         self.assertEqual(err.exception.decode_path, decode_path)
 
+    def test_allowable_invalid_chars(self):
+        for c, kwargs in (
+                ("*", {"allow_asterisk": True}),
+                ("&", {"allow_ampersand": True}),
+                ("&*", {"allow_asterisk": True, "allow_ampersand": True}),
+        ):
+            s = "hello invalid " + c
+            with assertRaisesRegex(self, DecodeError, "non-printable"):
+                self.base_klass(s)
+            self.base_klass(s, **kwargs)
+            klass = self.base_klass(**kwargs)
+            obj = klass(s)
+            obj = obj.copy()
+            obj(s)
+
 
 class TestTeletexString(
         UnicodeDecodeErrorMixin,