https://github.com/tahoe-lafs/pycryptopp/issues/42

--- old/src/pycryptopp/cipher/aesmodule.cpp
+++ old/src/pycryptopp/cipher/aesmodule.cpp
@@ -20,6 +20,8 @@
 #include <src-cryptopp/aes.h>
 #endif
 
+typedef unsigned char byte;
+
 static const char*const aes___doc__ = "_aes counter mode cipher\n\
 You are advised to run aes.start_up_self_test() after importing this module.";
 
--- old/src/pycryptopp/cipher/xsalsa20module.cpp
+++ old/src/pycryptopp/cipher/xsalsa20module.cpp
@@ -16,6 +16,8 @@
 #include <src-cryptopp/salsa.h>
 #endif
 
+typedef unsigned char byte;
+
 static const char* const xsalsa20__doc__ = "_xsalsa20 cipher";
 
 static PyObject *xsalsa20_error;
--- old/src/pycryptopp/hash/sha256module.cpp
+++ old/src/pycryptopp/hash/sha256module.cpp
@@ -21,6 +21,8 @@
 #include <src-cryptopp/filters.h>
 #endif
 
+typedef unsigned char byte;
+
 static const char*const sha256___doc__ = "_sha256 hash function";
 
 static PyObject *sha256_error;
--- old/src/pycryptopp/publickey/rsamodule.cpp
+++ old/src/pycryptopp/publickey/rsamodule.cpp
@@ -87,7 +87,7 @@
 VerifyingKey_serialize(VerifyingKey *self, PyObject *dummy) {
     std::string outstr;
     StringSink ss(outstr);
-    self->k->DEREncode(ss);
+    self->k->GetMaterial().Save(ss);
     PyStringObject* result = reinterpret_cast<PyStringObject*>(PyString_FromStringAndSize(outstr.c_str(), outstr.size()));
     if (!result)
         return NULL;
@@ -216,7 +216,7 @@
 SigningKey_serialize(SigningKey *self, PyObject *dummy) {
     std::string outstr;
     StringSink ss(outstr);
-    self->k->DEREncode(ss);
+    self->k->GetMaterial().Save(ss);
     PyStringObject* result = reinterpret_cast<PyStringObject*>(PyString_FromStringAndSize(outstr.c_str(), outstr.size()));
     if (!result)
         return NULL;