Crypto.Classes.Exceptions

The Hash class is intended as the generic interface targeted by maintainers of Haskell digest implementations. Using this generic interface, higher level functions such as hash and hash' provide a useful API for comsumers of hash implementations.

Any instantiated implementation must handle unaligned data.

Minimum complete definition: outputLength, blockLength, initialCtx, updateCtx, and finalize.

Asymetric ciphers (common ones being RSA or EC based)

A class of random bit generators that allows for the possibility of failure, reseeding, providing entropy at the same time as requesting bytes

Minimum complete definition: newGen, genSeedLength, genBytes, reseed, reseedInfo, reseedPeriod.

The BlockCipher class is intended as the generic interface targeted by maintainers of Haskell cipher implementations.

Minimum complete definition: blockSize, encryptBlock, decryptBlock, buildKey, and keyLength.

Instances must handle unaligned data

Obtain a strict hash function whose result is the same type as the given digest, which is discarded. If the type is already inferred then consider using the hash' function instead.

Obtain a lazy hash function whose result is the same type as the given digest, which is discarded. If the type is already inferred then consider using the hash function instead.

Key construction from raw material (typically including key expansion)

This is a wrapper that can throw a CipherError on exception.

Build a symmetric key using the system entropy (see System.Entropy)

Symmetric key generation

This is a wrapper that can throw a GenError on exception.

Random IV generation

This is a wrapper that can throw a GenError on exception.

Obtain an IV using the system entropy (see System.Entropy)

Obtain an IV made only of zeroes

Instantiate a new random bit generator. The provided bytestring should be of length >= genSeedLength. If the bytestring is shorter then the call may fail (suggested error: NotEnoughEntropy). If the bytestring is of sufficent length the call should always succeed.

This is a wrapper that can throw GenError types as exceptions.

genBytes len g generates a random ByteString of length len and new generator. The MonadCryptoRandom package has routines useful for converting the ByteString to commonly needed values (but cereal or other deserialization libraries would also work).

This is a wrapper that can throw GenError types as exceptions.

genBytesWithEntropy g i entropy generates i random bytes and use the additional input entropy in the generation of the requested data to increase the confidence our generated data is a secure random stream.

This is a wrapper that can throw GenError types as exceptions.

If the generator has produced too many random bytes on its existing seed it will throw a NeedReseed exception. In that case, reseed the generator using this function and a new high-entropy seed of length >= genSeedLength. Using bytestrings that are too short can result in an exception (NotEnoughEntropy).

While the safety and wisdom of a splitting function depends on the properties of the generator being split, several arguments from informed people indicate such a function is safe for NIST SP 800-90 generators. (see libraries@haskell.org discussion around Sept, Oct 2010). You can find implementations of such generators in the DRBG package.

This is a wrapper for splitGen which throws errors as exceptions.

Length of input entropy necessary to instantiate or reseed a generator

Indicates how soon a reseed is needed

Indicates the period between reseeds (constant for most generators).

By default this uses System.Entropy to obtain entropy for newGen. WARNING: The default implementation opens a file handle which will never be closed!

Generator failures should always return the appropriate GenError. Note GenError in an instance of exception but wether or not an exception is thrown depends on if the selected generator (read: if you don't want execptions from code that uses throw then pass in a generator that never has an error for the used functions)

Asymetric key generation

This is a wrapper that can throw a GenError on exception.

Asymmetric encryption

This is a wrapper that can throw a GenError on exception.

Asymmetric decryption

This is a wrapper that can throw a GenError on exception.

A class for signing operations which inherently can not be as generic as asymetric ciphers (ex: DSA).

Build a pair of asymmetric keys using the system random generator. WARNING: This function opens a file handle which will never be closed!