processPSKs :: (Cipher c, DH d, Hash h)
            => (ScrubbedBytes -> NoiseState c d h -> NoiseResult c d h)
            -> [ScrubbedBytes]
            -> NoiseResult c d h
            -> ([ScrubbedBytes], NoiseResult c d h)
processPSKs _ []                result = ([], result)
processPSKs :: (Cipher c, DH d, Hash h)
            => (ScrubbedBytes -> NoiseState c d h -> NoiseResult c d h)
            -> [ScrubbedBytes]
            -> NoiseResult c d h
            -> ([ScrubbedBytes], NoiseResult c d h)
processPSKs _ []                result = ([], result)
processPSKs _ []                result = ([], result)