query: curve25519-donna

[mrose17]

i have been looking around for a pure-javascript implementation of the "donna" -- https://code.google.com/p/curve25519-donna/ & http://cr.yp.to/ecdh.html

i have a sneaking suspicion that this is implemented in elliptic, although with a slightly different API/naming convention. am i right or just optimistic?

sorry for the lack of clue. thanks!

[indutny]

It seems to be just an alternative name for curve25519.

In this case - you could use either new elliptic.ec('curve25519') for ECDH(E) or new elliptic.ec('ed25519') for ECDSA.

[mrose17]

thanks very much for the reply. i was thinking that new elliptic.ec('curve25519') was the entry point for http://cr.yp.to/ecdh.html ...

what i wanted to confirm then is this: given key1 = ec.genKeyPair()

• key1.getPrivate('hex') corresponds to a 32-octet secret key with the bit manipulation on the first and final octets
• key1.getPublic() corresponds to a 32-octet public key corresponding to the secret key
• key1.derive(key2.getPublic()) corresponds to the 32-octet shared secret between key1 and another key, key2

what has me stumped is this: key1.getPublic('hex') throws an error in my test file:

node donna.js

/Users/mrose/Downloads/elliptic-master/lib/elliptic/ec/key.js:83
    var y = this.pub.getY().toArray();
                     ^
TypeError: Object #<Point> has no method 'getY'
    at KeyPair.getPublic (/Users/mrose/Downloads/elliptic-master/lib/elliptic/ec/key.js:83:22)
    at Object.<anonymous> (/Users/mrose/Downloads/elliptic-master/donna.js:9:32)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:902:3

so either i shouldn't be calling key1.getPublic with a parameter of hex or getY ought to be defined in mont.js in addition to short.js and edwards.js

sorry for the newbie questions... and, honestly, few things make me happier in my professional life that looking for a javascript-only implementation of something really complicated and finding it! many thanks!

[indutny]

@mrose17 ouch, you are right! Fixing it.

[mrose17]

@indutny - thanks! could i ask you to re-open the issue and then close it again, when it's fixed.

sorry!

[indutny]

@mrose17 please take a look at #22