Copyright	(c) Joseph Abrahamson 2013
License	MIT
Maintainer	me@jspha.com
Stability	experimental
Portability	non-portable
Safe Haskell	None
Language	Haskell2010

Crypto.Saltine.Core.Box

Description

Public-key cryptography abstraction: Crypto.Saltine.Core.Box

This module consists of functions dealing with two public-key cryptography concepts in libsodium.

The first one is an authenticated encryption scheme. In this scheme, the box function encrypts and authenticates a message ByteString using the sender's secret key, the receiver's public key, and a nonce. The boxOpen function verifies and decrypts a ciphertext ByteString using the receiver's secret key, the sender's public key, and a nonce. If the ciphertext fails verification, boxOpen returns Nothing.

The set of box functions is designed to meet the standard notions of privacy and third-party unforgeability for a public-key authenticated-encryption scheme using nonces. For formal definitions see, e.g., Jee Hea An, "Authenticated encryption in the public-key setting: security notions and analyses," http://eprint.iacr.org/2001/079.

Distinct messages between the same {sender, receiver} set are required to have distinct nonces. For example, the lexicographically smaller public key can use nonce 1 for its first message to the other key, nonce 3 for its second message, nonce 5 for its third message, etc., while the lexicographically larger public key uses nonce 2 for its first message to the other key, nonce 4 for its second message, nonce 6 for its third message, etc. Nonces are long enough that randomly generated nonces have negligible risk of collision.

There is no harm in having the same nonce for different messages if the {sender, receiver} sets are different. This is true even if the sets overlap. For example, a sender can use the same nonce for two different messages if the messages are sent to two different public keys.

The second concept is sealed boxes, which provide encryption and preservation of integrity, but not authentication. Technically, the sender of a message generates a keypair, uses the regular box mechanism, attaches the public key to the message and then immediately destroys the private key. This is useful, e.g. when the receiver cannot know the sender's public key in advance and hence cannot use the regular box functions, or when you want to send messages anonymously.

The Crypto.Saltine.Core.Box module is not meant to provide non-repudiation. On the contrary: the crypto_box function guarantees repudiability. A receiver can freely modify a boxed message, and therefore cannot convince third parties that this particular message came from the sender. The sender and receiver are nevertheless protected against forgeries by other parties. In the terminology of http://groups.google.com/group/sci.crypt/msg/ec5c18b23b11d82c, crypto_box uses "public-key authenticators" rather than "public-key signatures."

Users who want public verifiability (or receiver-assisted public verifiability) should instead use signatures (or signcryption). Signatures are documented in the Crypto.Saltine.Core.Sign module.

Crypto.Saltine.Core.Box is curve25519xsalsa20poly1305, a particular combination of Curve25519, Salsa20, and Poly1305 specified in "Cryptography in NaCl" (http://nacl.cr.yp.to/valid.html). This function is conjectured to meet the standard notions of privacy and third-party unforgeability.

This is version 2010.08.30 of the box.html web page.

Synopsis

data SecretKey
data PublicKey
data Keypair = Keypair {
- secretKey :: SecretKey
- publicKey :: PublicKey
}
data CombinedKey
data Nonce
newKeypair :: IO Keypair
beforeNM :: SecretKey -> PublicKey -> CombinedKey
newNonce :: IO Nonce
box :: PublicKey -> SecretKey -> Nonce -> ByteString -> ByteString
boxOpen :: PublicKey -> SecretKey -> Nonce -> ByteString -> Maybe ByteString
boxAfterNM :: CombinedKey -> Nonce -> ByteString -> ByteString
boxOpenAfterNM :: CombinedKey -> Nonce -> ByteString -> Maybe ByteString
boxSeal :: PublicKey -> ByteString -> IO ByteString
boxSealOpen :: PublicKey -> SecretKey -> ByteString -> Maybe ByteString

Documentation

data SecretKey Source #

An opaque box cryptographic secret key.

Instances

Instances details

Eq SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods (==) :: SecretKey -> SecretKey -> Bool # (/=) :: SecretKey -> SecretKey -> Bool #
Data SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> SecretKey -> c SecretKey # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c SecretKey # toConstr :: SecretKey -> Constr # dataTypeOf :: SecretKey -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c SecretKey) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c SecretKey) # gmapT :: (forall b. Data b => b -> b) -> SecretKey -> SecretKey # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> SecretKey -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> SecretKey -> r # gmapQ :: (forall d. Data d => d -> u) -> SecretKey -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> SecretKey -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> SecretKey -> m SecretKey # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> SecretKey -> m SecretKey # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> SecretKey -> m SecretKey #
Ord SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods compare :: SecretKey -> SecretKey -> Ordering # (<) :: SecretKey -> SecretKey -> Bool # (<=) :: SecretKey -> SecretKey -> Bool # (>) :: SecretKey -> SecretKey -> Bool # (>=) :: SecretKey -> SecretKey -> Bool # max :: SecretKey -> SecretKey -> SecretKey # min :: SecretKey -> SecretKey -> SecretKey #
Show SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods showsPrec :: Int -> SecretKey -> ShowS # show :: SecretKey -> String # showList :: [SecretKey] -> ShowS #
Generic SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Associated Types type Rep SecretKey :: Type -> Type # Methods from :: SecretKey -> Rep SecretKey x # to :: Rep SecretKey x -> SecretKey #
NFData SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods rnf :: SecretKey -> () #
Hashable SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods hashWithSalt :: Int -> SecretKey -> Int # hash :: SecretKey -> Int #
IsEncoding SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods encode :: SecretKey -> ByteString Source # decode :: ByteString -> Maybe SecretKey Source # encoded :: (Choice p, Applicative f) => p SecretKey (f SecretKey) -> p ByteString (f ByteString) Source #
type Rep SecretKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box type Rep SecretKey = D1 ('MetaData "SecretKey" "Crypto.Saltine.Internal.Box" "saltine-0.2.0.1-inplace" 'True) (C1 ('MetaCons "SK" 'PrefixI 'True) (S1 ('MetaSel ('Just "unSK") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 ByteString)))

data PublicKey Source #

An opaque box cryptographic public key.

Instances

Instances details

Eq PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods (==) :: PublicKey -> PublicKey -> Bool # (/=) :: PublicKey -> PublicKey -> Bool #
Data PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> PublicKey -> c PublicKey # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c PublicKey # toConstr :: PublicKey -> Constr # dataTypeOf :: PublicKey -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c PublicKey) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c PublicKey) # gmapT :: (forall b. Data b => b -> b) -> PublicKey -> PublicKey # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> PublicKey -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> PublicKey -> r # gmapQ :: (forall d. Data d => d -> u) -> PublicKey -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> PublicKey -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> PublicKey -> m PublicKey # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> PublicKey -> m PublicKey # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> PublicKey -> m PublicKey #
Ord PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods compare :: PublicKey -> PublicKey -> Ordering # (<) :: PublicKey -> PublicKey -> Bool # (<=) :: PublicKey -> PublicKey -> Bool # (>) :: PublicKey -> PublicKey -> Bool # (>=) :: PublicKey -> PublicKey -> Bool # max :: PublicKey -> PublicKey -> PublicKey # min :: PublicKey -> PublicKey -> PublicKey #
Show PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods showsPrec :: Int -> PublicKey -> ShowS # show :: PublicKey -> String # showList :: [PublicKey] -> ShowS #
Generic PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Associated Types type Rep PublicKey :: Type -> Type # Methods from :: PublicKey -> Rep PublicKey x # to :: Rep PublicKey x -> PublicKey #
NFData PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods rnf :: PublicKey -> () #
Hashable PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods hashWithSalt :: Int -> PublicKey -> Int # hash :: PublicKey -> Int #
IsEncoding PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods encode :: PublicKey -> ByteString Source # decode :: ByteString -> Maybe PublicKey Source # encoded :: (Choice p, Applicative f) => p PublicKey (f PublicKey) -> p ByteString (f ByteString) Source #
type Rep PublicKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box type Rep PublicKey = D1 ('MetaData "PublicKey" "Crypto.Saltine.Internal.Box" "saltine-0.2.0.1-inplace" 'True) (C1 ('MetaCons "PK" 'PrefixI 'True) (S1 ('MetaSel ('Just "unPK") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 ByteString)))

data Keypair Source #

A convenience type for keypairs

Constructors

Keypair
Fields secretKey :: SecretKey publicKey :: PublicKey

Instances

Instances details

Eq Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods (==) :: Keypair -> Keypair -> Bool # (/=) :: Keypair -> Keypair -> Bool #
Data Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Keypair -> c Keypair # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Keypair # toConstr :: Keypair -> Constr # dataTypeOf :: Keypair -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Keypair) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Keypair) # gmapT :: (forall b. Data b => b -> b) -> Keypair -> Keypair # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Keypair -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Keypair -> r # gmapQ :: (forall d. Data d => d -> u) -> Keypair -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Keypair -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Keypair -> m Keypair # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Keypair -> m Keypair # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Keypair -> m Keypair #
Ord Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods compare :: Keypair -> Keypair -> Ordering # (<) :: Keypair -> Keypair -> Bool # (<=) :: Keypair -> Keypair -> Bool # (>) :: Keypair -> Keypair -> Bool # (>=) :: Keypair -> Keypair -> Bool # max :: Keypair -> Keypair -> Keypair # min :: Keypair -> Keypair -> Keypair #
Generic Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Associated Types type Rep Keypair :: Type -> Type # Methods from :: Keypair -> Rep Keypair x # to :: Rep Keypair x -> Keypair #
NFData Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods rnf :: Keypair -> () #
Hashable Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods hashWithSalt :: Int -> Keypair -> Int # hash :: Keypair -> Int #
type Rep Keypair Source #
Instance details Defined in Crypto.Saltine.Internal.Box type Rep Keypair = D1 ('MetaData "Keypair" "Crypto.Saltine.Internal.Box" "saltine-0.2.0.1-inplace" 'False) (C1 ('MetaCons "Keypair" 'PrefixI 'True) (S1 ('MetaSel ('Just "secretKey") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 SecretKey) :*: S1 ('MetaSel ('Just "publicKey") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 PublicKey)))

data CombinedKey Source #

An opaque boxAfterNM cryptographic combined key.

Instances

Instances details

Eq CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods (==) :: CombinedKey -> CombinedKey -> Bool # (/=) :: CombinedKey -> CombinedKey -> Bool #
Data CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> CombinedKey -> c CombinedKey # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c CombinedKey # toConstr :: CombinedKey -> Constr # dataTypeOf :: CombinedKey -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c CombinedKey) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c CombinedKey) # gmapT :: (forall b. Data b => b -> b) -> CombinedKey -> CombinedKey # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> CombinedKey -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> CombinedKey -> r # gmapQ :: (forall d. Data d => d -> u) -> CombinedKey -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> CombinedKey -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> CombinedKey -> m CombinedKey # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> CombinedKey -> m CombinedKey # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> CombinedKey -> m CombinedKey #
Ord CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods compare :: CombinedKey -> CombinedKey -> Ordering # (<) :: CombinedKey -> CombinedKey -> Bool # (<=) :: CombinedKey -> CombinedKey -> Bool # (>) :: CombinedKey -> CombinedKey -> Bool # (>=) :: CombinedKey -> CombinedKey -> Bool # max :: CombinedKey -> CombinedKey -> CombinedKey # min :: CombinedKey -> CombinedKey -> CombinedKey #
Show CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods showsPrec :: Int -> CombinedKey -> ShowS # show :: CombinedKey -> String # showList :: [CombinedKey] -> ShowS #
Generic CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Associated Types type Rep CombinedKey :: Type -> Type # Methods from :: CombinedKey -> Rep CombinedKey x # to :: Rep CombinedKey x -> CombinedKey #
NFData CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods rnf :: CombinedKey -> () #
Hashable CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods hashWithSalt :: Int -> CombinedKey -> Int # hash :: CombinedKey -> Int #
IsEncoding CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods encode :: CombinedKey -> ByteString Source # decode :: ByteString -> Maybe CombinedKey Source # encoded :: (Choice p, Applicative f) => p CombinedKey (f CombinedKey) -> p ByteString (f ByteString) Source #
type Rep CombinedKey Source #
Instance details Defined in Crypto.Saltine.Internal.Box type Rep CombinedKey = D1 ('MetaData "CombinedKey" "Crypto.Saltine.Internal.Box" "saltine-0.2.0.1-inplace" 'True) (C1 ('MetaCons "CK" 'PrefixI 'True) (S1 ('MetaSel ('Just "unCK") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 ByteString)))

data Nonce Source #

An opaque box nonce.

Instances

Instances details

Eq Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods (==) :: Nonce -> Nonce -> Bool # (/=) :: Nonce -> Nonce -> Bool #
Data Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Nonce -> c Nonce # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Nonce # toConstr :: Nonce -> Constr # dataTypeOf :: Nonce -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Nonce) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Nonce) # gmapT :: (forall b. Data b => b -> b) -> Nonce -> Nonce # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Nonce -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Nonce -> r # gmapQ :: (forall d. Data d => d -> u) -> Nonce -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Nonce -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Nonce -> m Nonce # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Nonce -> m Nonce # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Nonce -> m Nonce #
Ord Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods compare :: Nonce -> Nonce -> Ordering # (<) :: Nonce -> Nonce -> Bool # (<=) :: Nonce -> Nonce -> Bool # (>) :: Nonce -> Nonce -> Bool # (>=) :: Nonce -> Nonce -> Bool # max :: Nonce -> Nonce -> Nonce # min :: Nonce -> Nonce -> Nonce #
Show Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods showsPrec :: Int -> Nonce -> ShowS # show :: Nonce -> String # showList :: [Nonce] -> ShowS #
Generic Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Associated Types type Rep Nonce :: Type -> Type # Methods from :: Nonce -> Rep Nonce x # to :: Rep Nonce x -> Nonce #
NFData Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods rnf :: Nonce -> () #
Hashable Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods hashWithSalt :: Int -> Nonce -> Int # hash :: Nonce -> Int #
IsNonce Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods zero :: Nonce Source # nudge :: Nonce -> Nonce Source #
IsEncoding Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box Methods encode :: Nonce -> ByteString Source # decode :: ByteString -> Maybe Nonce Source # encoded :: (Choice p, Applicative f) => p Nonce (f Nonce) -> p ByteString (f ByteString) Source #
type Rep Nonce Source #
Instance details Defined in Crypto.Saltine.Internal.Box type Rep Nonce = D1 ('MetaData "Nonce" "Crypto.Saltine.Internal.Box" "saltine-0.2.0.1-inplace" 'True) (C1 ('MetaCons "Nonce" 'PrefixI 'True) (S1 ('MetaSel ('Just "unNonce") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 ByteString)))

newKeypair :: IO Keypair Source #

Randomly generates a secret key and a corresponding public key.

beforeNM :: SecretKey -> PublicKey -> CombinedKey Source #

Build a CombinedKey for sending from SecretKey to PublicKey. This is a precomputation step which can accelerate later encryption calls.

newNonce :: IO Nonce Source #

Randomly generates a nonce for usage with box and boxOpen.

box Source #

Arguments

:: PublicKey
-> SecretKey
-> Nonce
-> ByteString	Message
-> ByteString	Ciphertext (incl. authentication tag)

Encrypts a message for sending to the owner of the public key. They must have your public key in order to decrypt the message. It is infeasible for an attacker to decrypt the message so long as the Nonce is not repeated.

boxOpen Source #

Arguments

:: PublicKey
-> SecretKey
-> Nonce
-> ByteString	Ciphertext (incl. authentication tag)
-> Maybe ByteString	Message

Decrypts a message sent from the owner of the public key. They must have encrypted it using your public key. Returns Nothing if the keys and message do not match.

boxAfterNM Source #

Arguments

:: CombinedKey
-> Nonce
-> ByteString	Message
-> ByteString	Ciphertext (incl. authentication tag)

box using a CombinedKey and thus faster.

boxOpenAfterNM Source #

Arguments

:: CombinedKey
-> Nonce
-> ByteString	Ciphertext (incl. authentication tag)
-> Maybe ByteString	Message

boxOpen using a CombinedKey and is thus faster.

boxSeal :: PublicKey -> ByteString -> IO ByteString Source #

Encrypts a message for sending to the owner of the public key. The message is unauthenticated, but permits integrity checking. This function is non-deterministic, it uses newly created ephemeral keys internally, and thus in IO.

boxSealOpen Source #

Arguments

:: PublicKey
-> SecretKey
-> ByteString	Ciphertext
-> Maybe ByteString	Message

Decrypts a sealed box message. The message must have been encrypted using the receiver's public key. Returns Nothing if keys and message do not match or integrity is violated.