hs-otr

Please do not use this code. I am not a cryptographer or security expert. It's probably FULL OF SECURITY HOLES. You have been warned.

Create a signing key

To create the DSA key you can do the following:

Create the parameter file.

This file can be reused for as many keys as you want.

openssl dsaparam -out <parameterfile.pem> 1024

The prime has to be 1024 bits in size, bigger key sizes unfortunately don't work with OTR.

Create the keypair

openssl gendsa -param <parameterfile.pem> -out <keyfile.pem>

Read the key

Here's a chunk of code to get the key pair from the file. It requires the packages

pem
crypto-pubkey-types
asn1-types
asn1-encoding

import           Crypto.Types.PubKey.DSA
import           Data.ASN1.BinaryEncoding
import           Data.ASN1.Encoding
import           Data.ASN1.Types
import qualified Data.ByteString.Lazy as BSL
import           Data.PEM

getKey = String ->  IO KeyPair
getKey keyFile = do
    Right ((PEM pName _ bs) : _) <- pemParseLBS `fmap` (BSL.readFile keyFile)
    let Right keysASN1 = decodeASN1 DER (BSL.fromChunks [bs])
    let Right (keyPair, _) = fromASN1 keysASN1
    return keyPair

Error handling is left as an exercise. ;-)

Philonous / hs-otr