python: Support the Assuan engine.

* lang/python/gpgme.i: Add typemaps for the Assuan protocol callbacks.
* lang/python/helpers.c (_pyme_assuan_{data,inquire,status}_cb): New
functions.
* lang/python/private.h (_pyme_assuan_{data,inquire,status}_cb): New
prototypes.
* lang/python/pyme/core.py (Context.assuan_transact): New method.
* lang/python/pyme/util.py (percent_escape): New function.
* lang/python/tests/Makefile.am (py_tests): Add new test.
* lang/python/tests/t-protocol-assuan.py: New file.

Signed-off-by: Justus Winter <[email protected]>

2 files changed, 56 insertions, 0 deletions

diff --git a/lang/python/pyme/core.py b/lang/python/pyme/core.py
index 216e26fd..b25808dc 100644
--- a/lang/python/pyme/core.py
+++ b/lang/python/pyme/core.py
@@ -31,6 +31,7 @@ from . import pygpgme
 from .errors import errorcheck, GPGMEError
 from . import constants
 from . import errors
+from . import util
 
 class GpgmeWrapper(object):
     """Base wrapper class
@@ -467,6 +468,55 @@ class Context(GpgmeWrapper):
             plainbytes = data.read()
         return plainbytes, result
 
+    def assuan_transact(self, command,
+                        data_cb=None, inquire_cb=None, status_cb=None):
+        """Issue a raw assuan command
+
+        This function can be used to issue a raw assuan command to the
+        engine.
+
+        If command is a string or bytes, it will be used as-is.  If it
+        is an iterable of strings, it will be properly escaped and
+        joined into an well-formed assuan command.
+
+        Keyword arguments:
+        data_cb		-- a callback receiving data lines
+        inquire_cb	-- a callback providing more information
+        status_cb	-- a callback receiving status lines
+
+        Returns:
+        result		-- the result of command as GPGMEError
+
+        Raises:
+        GPGMEError	-- as signaled by the underlying library
+
+        """
+
+        if isinstance(command, (str, bytes)):
+            cmd = command
+        else:
+            cmd = " ".join(util.percent_escape(f) for f in command)
+
+        errptr = pygpgme.new_gpgme_error_t_p()
+
+        err = pygpgme.gpgme_op_assuan_transact_ext(
+            self.wrapped,
+            cmd,
+            (weakref.ref(self), data_cb) if data_cb else None,
+            (weakref.ref(self), inquire_cb) if inquire_cb else None,
+            (weakref.ref(self), status_cb) if status_cb else None,
+            errptr)
+
+        if self._callback_excinfo:
+            pygpgme.pygpgme_raise_callback_exception(self)
+
+        errorcheck(err)
+
+        status = pygpgme.gpgme_error_t_p_value(errptr)
+        pygpgme.delete_gpgme_error_t_p(errptr)
+
+        return GPGMEError(status) if status != 0 else None
+
     @property
     def signers(self):
         """Keys used for signing"""
diff --git a/lang/python/pyme/util.py b/lang/python/pyme/util.py
index bbd28fe7..7eb6353f 100644
--- a/lang/python/pyme/util.py
+++ b/lang/python/pyme/util.py
@@ -31,3 +31,9 @@ def process_constants(prefix, scope):
                  if identifier.startswith(prefix)}
     scope.update(constants)
     return list(constants.keys())
+
+def percent_escape(s):
+    return ''.join(
+        '%{0:2x}'.format(ord(c))
+        if c == '+' or c == '"' or c == '%' or ord(c) <= 0x20 else c
+        for c in s)