Initial (only partially working) attempt to allow filters to be implemented

in Python.

3 files changed, 79 insertions, 9 deletions

diff --git a/misc/python/src/filter.cpp b/misc/python/src/filter.cpp
index bf3632fab..edd282048 100644
--- a/misc/python/src/filter.cpp
+++ b/misc/python/src/filter.cpp
@@ -1,6 +1,6 @@
 /*************************************************
-* Wrappers for Botan Filters                     *
-* (C) 2005-2006 Jack Lloyd <[email protected]> *
+* Boost.Python module definition                 *
+* (C) 1999-2006 The Botan Project                *
 *************************************************/
 
 #include <boost/python.hpp>
@@ -10,6 +10,46 @@ using namespace boost::python;
 #include <botan/lookup.h>
 using namespace Botan;
 
+class StringFilter : public Filter
+   {
+   public:
+      virtual void write_str(const std::string&) = 0;
+      void write(const byte data[], u32bit length)
+         {
+         write_str(std::string((const char*)data, length));
+         }
+
+      void send_str(const std::string& str)
+         {
+         send((const byte*)str.data(), str.length());
+         }
+   };
+
+class FilterWrapper : public StringFilter, public wrapper<StringFilter>
+   {
+   public:
+      void start_msg()
+         {
+         if(override start_msg = this->get_override("start_msg"))
+            start_msg();
+         }
+
+      void end_msg()
+         {
+         if(override end_msg = this->get_override("end_msg"))
+            end_msg();
+         }
+
+      void default_start_msg() {}
+      void default_end_msg() {}
+
+      virtual void write_str(const std::string& str)
+         {
+         this->get_override("write")(str);
+         }
+
+   };
+
 Filter* return_or_raise(Filter* filter, const std::string& name)
    {
    if(filter)
@@ -65,6 +105,12 @@ void append_filter(Pipe& pipe, std::auto_ptr<Filter> filter)
    filter.release();
    }
 
+void append_pyfilter(Pipe& pipe, std::auto_ptr<FilterWrapper> filter)
+   {
+   pipe.append(filter.get());
+   filter.release();
+   }
+
 void prepend_filter(Pipe& pipe, std::auto_ptr<Filter> filter)
    {
    pipe.prepend(filter.get());
@@ -87,6 +133,15 @@ void export_filters()
    def("make_filter", make_filter4,
        return_value_policy<manage_new_object>());
 
+   // This might not work - Pipe will delete the filter, but Python
+   // might have allocated the space with malloc() or who-knows-what -> bad
+   class_<FilterWrapper, std::auto_ptr<FilterWrapper>, boost::noncopyable>
+      ("FilterObj")
+      .def("write", pure_virtual(&StringFilter::write_str))
+      .def("send_str", &StringFilter::send_str)
+      .def("start_msg", &Filter::start_msg, &FilterWrapper::default_start_msg)
+      .def("end_msg", &Filter::end_msg, &FilterWrapper::default_end_msg);
+
    void (Pipe::*pipe_write_str)(const std::string&) = &Pipe::write;
    void (Pipe::*pipe_process_str)(const std::string&) = &Pipe::process_msg;
 
@@ -97,6 +152,7 @@ void export_filters()
       .add_property("default_msg", &Pipe::default_msg, &Pipe::set_default_msg)
       .add_property("msg_count", &Pipe::message_count)
       .def("append", append_filter)
+      .def("append", append_pyfilter)
       .def("prepend", prepend_filter)
       .def("reset", &Pipe::reset)
       .def("pop", &Pipe::pop)
diff --git a/misc/python/src/x509.cpp b/misc/python/src/x509.cpp
index af50dc903..d51d5e706 100644
--- a/misc/python/src/x509.cpp
+++ b/misc/python/src/x509.cpp
@@ -1,6 +1,6 @@
 /*************************************************
-* Wrappers for X.509 types                       *
-* (C) 2005-2006 Jack Lloyd <[email protected]> *
+* Boost.Python module definition                 *
+* (C) 1999-2006 The Botan Project                *
 *************************************************/
 
 #include <botan/oids.h>
diff --git a/misc/python/test.py b/misc/python/test.py
index e2f1e61fa..416797099 100755
--- a/misc/python/test.py
+++ b/misc/python/test.py
@@ -2,16 +2,30 @@
 
 import sys, botan
 
+class PyFilter(botan.FilterObj):
+    def start_msg(self):
+        print "PyFilter start_msg"
+        self.send_str('initial')
+
+    def end_msg(self):
+        print "PyFilter end_msg"
+
+    def write(self, data):
+        print "PyFilter write called with", data
+        self.send_str(data.replace('h', 'r'))
+
 def encrypt(input):
-    pipe = botan.Pipe(botan.Filter("ARC4",
-                                   key = botan.SymmetricKey("AABB")),
-                      botan.Filter("Hex_Encoder"))
+    filter = PyFilter()
+    
+    pipe = botan.Pipe(filter)
 
     pipe.start_msg()
     pipe.write(input)
     pipe.end_msg()
 
-    return pipe.read_all()
+    str = pipe.read_all()
+    print str
+    return str
 
 def decrypt(input):
     pipe = botan.Pipe(botan.Filter("Hex_Decoder"),
@@ -24,7 +38,7 @@ def decrypt(input):
 def main():
     ciphertext = encrypt("hi chappy")
     print ciphertext
-    print decrypt(ciphertext)
+    #print decrypt(ciphertext)
 
 if __name__ == "__main__":
     sys.exit(main())