crypto-api-0.12.2: A generic interface for cryptographic operations

Safe HaskellNone



A small selection of utilities that might be of use to others working with bytestring/number combinations.



incBS :: ByteString -> ByteStringSource

incBS bs inefficiently computes the value i2bs (8 * B.length bs) (bs2i bs + 1)

i2bs :: Int -> Integer -> ByteStringSource

i2bs bitLen i converts i to a ByteString of bitLen bits (must be a multiple of 8).

i2bs_unsized :: Integer -> ByteStringSource

i2bs_unsized i converts i to a ByteString of sufficient bytes to express the integer. The integer must be non-negative and a zero will be encoded in one byte.

throwLeft :: Exception e => Either e a -> aSource

Useful utility to extract the result of a generator operation and translate error results to exceptions.

for :: Tagged a b -> a -> bSource

Obtain a tagged value for a particular instantiated type.

(.::.) :: Tagged a b -> a -> bSource

Infix for operator

constTimeEq :: ByteString -> ByteString -> BoolSource

Checks two bytestrings for equality without breaches for timing attacks.

Semantically, constTimeEq = (==). However, x == y takes less time when the first byte is different than when the first byte is equal. This side channel allows an attacker to mount a timing attack. On the other hand, constTimeEq always takes the same time regardless of the bytestrings' contents, unless they are of difference size.

You should always use constTimeEq when comparing secrets, otherwise you may leave a significant security hole (cf.

bs2i :: ByteString -> IntegerSource

Helper function to convert bytestrings to integers

zwp' :: ByteString -> ByteString -> ByteStringSource

zipWith xor + Pack As a result of rewrite rules, this should automatically be optimized (at compile time). to use the bytestring libraries zipWith' function.