crypto.getDiffieHellman missing

[juliangruber]

will see if i can come up with a pr

[calvinmetcalf]

@indutny I figured I was missing something, thanks

[calvinmetcalf]

I don't think the modp primes are psudo-mersenne primes modp1 is 2^768 - 2^704 - 1 + 2^64 * { [2^638 pi] + 149686 } so k (which would have to be less then 2^(768/2) or 2^384 ) would be 36f0255dde973dcb3b399d747f23e32ed6fdb1f77598338bfdf44159c4ec64ddaeb5f78671cbfb22106ae64c32c5bce4cfd4f5920da0ebc8b01eca9292ae3dba1b7a4a899da181390bb3bd1659c5c9df0000000000000001 which comes out to be bigger then 2^384

[indutny]

@calvinmetcalf what prime are you using? :) Not every prime is pseudo-mersenne prime.

[calvinmetcalf]

the modp primes you get from crypto.getDiffieHellman, pseudo-mersenne might only work as a speed up when a prime is generated

On Mon, Nov 3, 2014 at 11:12 PM, Fedor Indutny notifications@github.com wrote:

@calvinmetcalf https://github.com/calvinmetcalf what prime are you using? :) Not every prime is pseudo-mersenne prime.

— Reply to this email directly or view it on GitHub https://github.com/dominictarr/crypto-browserify/issues/12#issuecomment-61591250 .

-Calvin W. Metcalf

[indutny]

Ah, it is for random primes. I guess then the Montgomery is the only way to go right now in bn.js.

[calvinmetcalf]

@indutny worse, random ones might sometimes work, these are specced to never work :) when generating primes we can (try) to make them pseudo-mersenne

[indutny]

@calvinmetcalf I think it is pretty dangerous business. I'd rather keep them random.

[calvinmetcalf]

I'm adding in the ability to generate primes, but the modp stuff is mainly to copy the current node api..

[calvinmetcalf]

Right read what you were responding to, generating them fully randomly

[dominictarr]

closed by: https://github.com/dominictarr/crypto-browserify/pull/62