Botan.MAC

A Message Authentication Code algorithm computes a tag over a message utilizing a shared secret key. Thus a valid tag confirms the authenticity and integrity of the message. Only entities in possession of the shared secret key are able to verify the tag.

Note

When combining a MAC with unauthenticated encryption mode, prefer to first encrypt the message and then MAC the ciphertext. The alternative is to MAC the plaintext, which depending on exact usage can suffer serious security issues. For a detailed discussion of this issue see the paper “The Order of Encryption and Authentication for Protecting Communications” by Hugo Krawczyk

The Botan MAC computation is split into five stages.

• Instantiate the MAC algorithm.
• Set the secret key.
• Process IV.
• Process data.
• Finalize the MAC computation.

Message Authentication Codes

Usage

Idiomatic interface

Data type

data MAC

Constructors

CMAC BlockCipher

GMAC BlockCipher

CBC_MAC BlockCipher -- No longer supported (possibly due to security issues)

HMAC CryptoHash

Poly1305

KMAC_128 Int -- Output length | KMAC_256 Int -- Output length

SipHash Int Int

X9_19_MAC

Instances

Show MAC

Defined in Botan.MAC

Methods

showsPrec :: Int -> MAC -> ShowS

show :: MAC -> String

showList :: [MAC] -> ShowS

Eq MAC

Defined in Botan.MAC

Methods

(==) :: MAC -> MAC -> Bool

(/=) :: MAC -> MAC -> Bool

Enumerations

macs :: [MAC]

Associated types

type MACKeySpec = KeySpec

type MACKey = ByteString

newMACKey :: MonadRandomIO m => MAC -> m MACKey

newMACKeyMaybe :: MonadRandomIO m => Int -> MAC -> m (Maybe MACKey)

type MACDigest = ByteString

Accessors

macName :: MAC -> ByteString

macKeySpec :: MAC -> KeySpec

macDigestLength :: MAC -> Int

Idiomatic algorithm

mac :: MAC -> MACKey -> ByteString -> Maybe MACDigest

gmac :: MAC -> MACKey -> GMACNonce -> ByteString -> Maybe MACDigest

macLazy :: MAC -> MACKey -> ByteString -> Maybe MACDigest

Mutable interface

Tagged mutable context

data MutableMAC

Constructors

MkMutableMAC

Fields

• mutableMACType :: MAC
• mutableMACCtx :: MAC

Destructor

destroyMAC :: MonadIO m => MutableMAC -> m ()

Initializers

newMAC :: MonadIO m => MAC -> m MutableMAC

Accessors

getMACName :: MonadIO m => MutableMAC -> m MACName

getMACKeySpec :: MonadIO m => MutableMAC -> m MACKeySpec

getMACDigestLength :: MonadIO m => MutableMAC -> m Int

setMACKey :: MonadIO m => MACKey -> MutableMAC -> m Bool

GMAC-specific functions

type GMACNonce = ByteString

setGMACNonce :: MonadIO m => GMACNonce -> MutableMAC -> m ()

Accessory functions

clearMAC :: MonadIO m => MutableMAC -> m ()

Mutable algorithm

updateMAC :: MonadIO m => MutableMAC -> ByteString -> m ()

finalizeMAC :: MonadIO m => MutableMAC -> m MACDigest

updateFinalizeMAC :: MonadIO m => MutableMAC -> ByteString -> m MACDigest

updateFinalizeClearMAC :: MonadIO m => MutableMAC -> ByteString -> m MACDigest

Algorithm references

cmac :: BlockCipher -> MAC

GMAC BlockCipher -- Requires a nonce "GMAC can accept initialization vectors of arbitrary length" | HMAC Hash -- Must be a (CS)Hash, and not a Checksum -- New in 3.2 -- | KMAC_128 Int -- Output length -- | KMAC_256 Int -- Output length | Poly1305 -- Requires a unique key per message (key r and nonce s have been combined) | SipHash Int Int -- Number of input and finalization rounds | X9_19_MAC

hmac :: CryptoHash -> MAC

poly1305 :: MAC

sipHash :: MAC

x9_19_mac :: MAC