WARNING: THIS CODE HAS NOT BEEN AUDITED. TIMING ATTACKS ARE ESPECIALLY OF CONCERN. YOU PROBABLY SHOULD NOT USE IT.
An emscripten compiled port of curve25519-donna, with a super light wrapper around it.
Interacting with the compiled JS from your own code can be a bit of a pain thanks to pointers and what not. I've tried to abstract this away with a light wrapper around the compiled code from emscripten. There are two functions.
// A key is a 32 byte Uint8Array
curve25519.getPublicFromPrivate(privateKey);
curve25519.getSharedSecret(myPrivate, theirPublic);The implementation of curve25519 in this repo is from agl/curve25519-donna. If you'd like to compile the library yourself, there is a nice Make file that will run the commands. You need to have emcc (the emscripten compiler) and uglifyjs in your path for it to do its thing.
Testing is pretty simple right now. Open up test/test.html in a browser to see it at work.
The c/curve25519-donna.c file has its own license from Google. See the comment in that file. That's where the meat of this comes from. The little wrapper I wrote around it is in the public domain.
The wrapper is pretty simple, so hopefully it won't need many bug fixes once it's stable. If you see something wrong or you have something to add, feel free to open up an issue or submit a pull request. I'll take a look and we'll decide if it should be patched in.
All contributions have to be licensed in the public domain like the rest of the wrapper.
Changes to the C code don't belong here of course.