Cable-Desktop/nacl/curve25519-donna-wrapper.cpp
2014-07-20 16:49:40 -04:00

142 lines
3.9 KiB
C++

/*
* Copyright (c) 2013 Matt Corallo
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "curve25519-donna.h"
#include "ed25519/additions/curve_sigs.h"
#include <ppapi/cpp/instance.h>
#include <ppapi/cpp/module.h>
#include <ppapi/cpp/var.h>
#include <ppapi/cpp/var_dictionary.h>
#include <ppapi/cpp/var_array_buffer.h>
#include <string.h>
const unsigned char basepoint[32] = {9};
template<int Length>
class AutoArrayBufferObject {
private:
pp::VarArrayBuffer buf;
unsigned char* map;
public:
AutoArrayBufferObject(pp::Var v) : buf(v), map(NULL) {}
unsigned char *Get() {
if (map)
return map;
if (buf.is_null())
return NULL;
if (Length > 0 && buf.ByteLength() != Length)
return NULL;
map = static_cast<unsigned char*>(buf.Map());
return map;
}
long GetLength() {
return buf.is_null() ? -1 : buf.ByteLength();
}
~AutoArrayBufferObject() {
if (map)
buf.Unmap();
}
};
class Curve25519Instance : public pp::Instance {
public:
explicit Curve25519Instance(PP_Instance instance) : pp::Instance(instance) {}
virtual void HandleMessage(const pp::Var& var_message) {
if (!var_message.is_dictionary())
return; // Go away broken client
pp::VarDictionary dictionary(var_message);
std::string command = dictionary.Get("command").AsString();
pp::VarDictionary returnMessage;
pp::VarArrayBuffer resBuffer(64);
unsigned char* res = static_cast<unsigned char*>(resBuffer.Map());
if (command == "bytesToPriv") {
AutoArrayBufferObject<32> priv(dictionary.Get("priv"));
if (!priv.Get())
return; // Go away broken client
memcpy(res, priv.Get(), 32);
res[0] &= 248;
res[31] &= 127;
res[31] |= 64;
} else if (command == "privToPub") {
AutoArrayBufferObject<32> priv(dictionary.Get("priv"));
if (!priv.Get())
return; // Go away broken client
curve25519_donna(res, priv.Get(), basepoint);
} else if (command == "ECDHE") {
AutoArrayBufferObject<32> priv(dictionary.Get("priv"));
AutoArrayBufferObject<32> pub(dictionary.Get("pub"));
if (!priv.Get() || !pub.Get())
return; // Go away broken client
curve25519_donna(res, priv.Get(), pub.Get());
} else if (command == "Ed25519Sign") {
AutoArrayBufferObject<32> priv(dictionary.Get("priv"));
AutoArrayBufferObject<-1> msg(dictionary.Get("msg"));
if (!priv.Get() || !msg.Get())
return; // Go away broken client
curve25519_sign(res, priv.Get(), msg.Get(), msg.GetLength());
}
resBuffer.Unmap();
if (command != "Ed25519Verify")
returnMessage.Set("res", resBuffer);
else {
AutoArrayBufferObject<32> pub(dictionary.Get("pub"));
AutoArrayBufferObject<-1> msg(dictionary.Get("msg"));
AutoArrayBufferObject<64> sig(dictionary.Get("sig"));
if (!pub.Get() || !msg.Get() || !sig.Get())
return; // Go away broken client
bool res = curve25519_verify(sig.Get(), pub.Get(), msg.Get(), msg.GetLength()) == 0;
returnMessage.Set("res", res);
}
returnMessage.Set("call_id", dictionary.Get("call_id").AsInt());
PostMessage(returnMessage);
}
};
class Curve25519Module : public pp::Module {
public:
Curve25519Module() : pp::Module() {}
virtual pp::Instance* CreateInstance(PP_Instance instance) {
return new Curve25519Instance(instance);
}
};
namespace pp {
Module* CreateModule() {
return new Curve25519Module();
}
}