Fixing decrypt script for modified model

Author: martinthomson

nodejs/decrypt.js

@@ -4,20 +4,26 @@ var base64 = require('urlsafe-base64');
 var crypto = require('crypto');
 var ece = require('./ece.js');
 
-if (process.argv.length < 6) {
+if (process.argv.length < 7) {
   console.warn('Usage: ' + process.argv.slice(0, 2).join(' ') +
-               ' <receiver-private> <sender-public> <salt> <message>');
+               ' <receiver-private> <receiver-public> <sender-public> <salt> <message>');
   process.exit(2);
 }
 
 var receiver = crypto.createECDH('prime256v1');
+// node crypto is finicky about accessing the public key
+// 1. it can't generate the public key from the private key
+// 2. it barfs when you try to access the public key, even after you set it
+// This hack squelches the complaints at the cost of a few wasted cycles
+receiver.generateKeys();
+receiver.setPublicKey(base64.decode(process.argv[3]));
 receiver.setPrivateKey(base64.decode(process.argv[2]));
-ece.saveKey('keyid', receiver);
+ece.saveKey('keyid', receiver, "P-256");
 
-var result = ece.decrypt(base64.decode(process.argv[5]), {
+var result = ece.decrypt(base64.decode(process.argv[6]), {
   keyid: 'keyid',
-  dh: process.argv[3],
-  salt: process.argv[4]
+  dh: process.argv[4],
+  salt: process.argv[5]
 });
 
 console.log(base64.encode(result));