Cable-Desktop/build/curve25519.js
lilia 2f58ea5f3a Fixup curve25519 module
Rename methods on the curve25519 interface to be a bit more high level.
Cleanup emscripten wrapper class, wrap long lines and such. Also add a
grunt task alias for building the emscripten compiled curve
implementation.
2014-11-09 15:30:37 -08:00

124 lines
4.5 KiB
JavaScript

/* vim: ts=4:sw=4:expandtab
*
* 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/>.
*/
;(function() {
'use strict';
// Insert some bytes into the emscripten memory and return a pointer
function _allocate(bytes) {
var address = Module._malloc(bytes.length);
Module.HEAPU8.set(bytes, address);
return address;
}
function _readBytes(address, length, array) {
array.set(Module.HEAPU8.subarray(address, address + length));
}
var basepoint = new Uint8Array(32);
basepoint[0] = 9;
window.curve25519 = {
keyPair: function(privKey) {
var priv = new Uint8Array(privKey);
priv[0] &= 248;
priv[31] &= 127;
priv[31] |= 64
// Where to store the result
var publicKey_ptr = Module._malloc(32);
// Get a pointer to the private key
var privateKey_ptr = _allocate(priv);
// The basepoint for generating public keys
var basepoint_ptr = _allocate(basepoint);
// The return value is just 0, the operation is done in place
var err = Module._curve25519_donna(publicKey_ptr,
privateKey_ptr,
basepoint_ptr);
var res = new Uint8Array(32);
_readBytes(publicKey_ptr, 32, res);
return Promise.resolve({ pubKey: res.buffer, privKey: privKey });
},
sharedSecret: function(pubKey, privKey) {
// Where to store the result
var sharedKey_ptr = Module._malloc(32);
// Get a pointer to our private key
var privateKey_ptr = _allocate(new Uint8Array(privKey));
// Get a pointer to their public key, the basepoint when you're
// generating a shared secret
var basepoint_ptr = _allocate(new Uint8Array(pubKey));
// Return value is 0 here too of course
var err = Module._curve25519_donna(sharedKey_ptr,
privateKey_ptr,
basepoint_ptr);
var res = new Uint8Array(32);
_readBytes(sharedKey_ptr, 32, res);
return Promise.resolve(res.buffer);
},
sign: function(privKey, message) {
// Where to store the result
var signature_ptr = Module._malloc(32);
// Get a pointer to our private key
var privateKey_ptr = _allocate(new Uint8Array(privKey));
// Get a pointer to the message
var message_ptr = _allocate(new Uint8Array(message));
var err = Module._curve25519_sign(signature_ptr,
privateKey_ptr,
message_ptr,
message.byteLength);
var res = new Uint8Array(64);
_readBytes(signature_ptr, 64, res);
return Promise.resolve(res.buffer);
},
verify: function(pubKey, message, sig) {
// Get a pointer to their public key
var publicKey_ptr = _allocate(new Uint8Array(pubKey));
// Get a pointer to the signature
var signature_ptr = _allocate(new Uint8Array(sig));
// Get a pointer to the message
var message_ptr = _allocate(new Uint8Array(message));
var res = Module._curve25519_verify(signature_ptr,
publicKey_ptr,
message_ptr,
message.byteLength);
return new Promise(function(resolve, reject) {
if (res !== 0) {
reject(new Error("Invalid signature"));
} else {
resolve();
}
});
}
};
})();