signatureHashData SignatureDSS mhash =
    case mhash of
        Nothing       -> SHA1
        Just HashSHA1 -> SHA1
        Just _        -> error "invalid DSA hash choice, only SHA1 allowed"
signatureHashData SignatureDSS mhash =
    case mhash of
        Nothing       -> SHA1
        Just HashSHA1 -> SHA1
        Just _        -> error "invalid DSA hash choice, only SHA1 allowed"
signatureHashData SignatureDSS mhash =
    case mhash of
        Nothing       -> SHA1
        Just HashSHA1 -> SHA1
        Just _        -> error "invalid DSA hash choice, only SHA1 allowed"