oblivious-file-sharing/obliv-c-ssl

Obliv-C with TLS support

This repository contains a modified version of Obliv-C with TLS support.

The original Obliv-C can be found here: https://github.com/samee/obliv-c

In particular, two parties in the secure computation share a pre-shared secret key and use the TLS protocol for network communication.

Installation

Please follow the original Obliv-C installation instructions.

In addition, we require tcmalloc, which is part of Google's gperftools.

For Ubuntu, it can be installed using apt-get.

sudo apt-get install libgoogle-perftools-dev

The rest of the steps are similar with the original Obliv-C's.

Example

A toy, insecure example to set up the TLS connections is as follow:

void ocTestUtilTcpOrDieBuffered(ProtocolDesc* pd, bool isServer, const char* remote_host, const char* port, bool isProfiled, size_t first_party_send_buffer_size, size_t second_party_send_buffer_size) {
	const char key[] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF};
	if(isServer) {
		int res;
		res = protocolAcceptTLS2P(pd, port, key, isProfiled, first_party_send_buffer_size);
		if(res!=0) {
			fprintf(stderr,"TLS accept failed\n");
			exit(1);
		}
	} else {
		int res;
		res = protocolConnectTLS2P(pd, remote_host, port, key, isProfiled, second_party_send_buffer_size);
		if (res!=0) {
			fprintf(stderr,"TLS connect failed\n");
			exit(1);
		}
	}
}	

Note that key is the pre-shared secret key. One should better not hard-code this key in the code.

Buffering is crucial for the performance since every TLS packet needs to carry additional payload. Thus, the buffer sizes need to be provided. Some of our experiments use 32768 and yield a good result.

Licenses

Note that this library is based on CIL and Obliv-C. They both use BSD licenses.

See LICENSE-cil and LICENSE-oblivcc for more information.