Network.Haskoin.Script

This package provides functions for parsing and evaluating bitcoin transaction scripts. Data types are provided for building and deconstructing all of the standard input and output script types.

Scripts

More informations on scripts is available here: http://en.bitcoin.it/wiki/Script

data Script

Data type representing a transaction script. Scripts are defined as lists of script operators ScriptOp. Scripts are used to:

• Define the spending conditions in the output of a transaction
• Provide the spending signatures in the input of a transaction

Constructors

Script

Fields

scriptOps :: ![ScriptOp]

List of script operators defining this script

Instances

Eq Script

Read Script

Show Script

Binary Script

NFData Script

data ScriptOp

Data type representing all of the operators allowed inside a Script.

Constructors

OP_PUSHDATA !ByteString !PushDataType

OP_0

OP_1NEGATE

OP_RESERVED

OP_1

OP_2

OP_3

OP_4

OP_5

OP_6

OP_7

OP_8

OP_9

OP_10

OP_11

OP_12

OP_13

OP_14

OP_15

OP_16

OP_NOP

OP_VER

OP_IF

OP_NOTIF

OP_VERIF

OP_VERNOTIF

OP_ELSE

OP_ENDIF

OP_VERIFY

OP_RETURN

OP_TOALTSTACK

OP_FROMALTSTACK

OP_IFDUP

OP_DEPTH

OP_DROP

OP_DUP

OP_NIP

OP_OVER

OP_PICK

OP_ROLL

OP_ROT

OP_SWAP

OP_TUCK

OP_2DROP

OP_2DUP

OP_3DUP

OP_2OVER

OP_2ROT

OP_2SWAP

OP_CAT

OP_SUBSTR

OP_LEFT

OP_RIGHT

OP_SIZE

OP_INVERT

OP_AND

OP_OR

OP_XOR

OP_EQUAL

OP_EQUALVERIFY

OP_RESERVED1

OP_RESERVED2

OP_1ADD

OP_1SUB

OP_2MUL

OP_2DIV

OP_NEGATE

OP_ABS

OP_NOT

OP_0NOTEQUAL

OP_ADD

OP_SUB

OP_MUL

OP_DIV

OP_MOD

OP_LSHIFT

OP_RSHIFT

OP_BOOLAND

OP_BOOLOR

OP_NUMEQUAL

OP_NUMEQUALVERIFY

OP_NUMNOTEQUAL

OP_LESSTHAN

OP_GREATERTHAN

OP_LESSTHANOREQUAL

OP_GREATERTHANOREQUAL

OP_MIN

OP_MAX

OP_WITHIN

OP_RIPEMD160

OP_SHA1

OP_SHA256

OP_HASH160

OP_HASH256

OP_CODESEPARATOR

OP_CHECKSIG

OP_CHECKSIGVERIFY

OP_CHECKMULTISIG

OP_CHECKMULTISIGVERIFY

OP_NOP1

OP_NOP2

OP_NOP3

OP_NOP4

OP_NOP5

OP_NOP6

OP_NOP7

OP_NOP8

OP_NOP9

OP_NOP10

OP_PUBKEYHASH

OP_PUBKEY

OP_INVALIDOPCODE !Word8

Instances

Eq ScriptOp

Read ScriptOp

Show ScriptOp

Binary ScriptOp

NFData ScriptOp

data PushDataType

Data type representing the type of an OP_PUSHDATA opcode.

Constructors

OPCODE

The next opcode bytes is data to be pushed onto the stack

OPDATA1

The next byte contains the number of bytes to be pushed onto the stack

OPDATA2

The next two bytes contains the number of bytes to be pushed onto the stack

OPDATA4

The next four bytes contains the number of bytes to be pushed onto the stack

Instances

Eq PushDataType

Read PushDataType

Show PushDataType

NFData PushDataType

opPushData :: ByteString -> ScriptOp

Optimally encode data using one of the 4 types of data pushing opcodes

Script Parsing

Script Outputs

data ScriptOutput

Data type describing standard transaction output scripts. Output scripts provide the conditions that must be fulfilled for someone to spend the output coins.

Constructors

PayPK

Pay to a public key.

Fields

getOutputPubKey :: !PubKey

PayPKHash

Pay to a public key hash.

Fields

getOutputAddress :: !Address

PayMulSig

Pay to multiple public keys.

Fields

getOutputMulSigKeys :: ![PubKey]

getOutputMulSigRequired :: !Int

PayScriptHash

Pay to a script hash.

Fields

getOutputAddress :: !Address

Instances

Eq ScriptOutput

Read ScriptOutput

Show ScriptOutput

ToJSON ScriptOutput

FromJSON ScriptOutput

NFData ScriptOutput

encodeOutput :: ScriptOutput -> Script

Computes a Script from a ScriptOutput. The Script is a list of ScriptOp can can be used to build a Tx.

encodeOutputBS :: ScriptOutput -> ByteString

Similar to encodeOutput but encodes to a ByteString

decodeOutput :: Script -> Either String ScriptOutput

Tries to decode a ScriptOutput from a Script. This can fail if the script is not recognized as any of the standard output types.

decodeOutputBS :: ByteString -> Either String ScriptOutput

Similar to decodeOutput but decodes from a ByteString

isPayPK :: ScriptOutput -> Bool

Returns True if the script is a pay to public key output.

isPayPKHash :: ScriptOutput -> Bool

Returns True if the script is a pay to public key hash output.

isPayMulSig :: ScriptOutput -> Bool

Returns True if the script is a pay to multiple public keys output.

isPayScriptHash :: ScriptOutput -> Bool

Returns true if the script is a pay to script hash output.

scriptAddr :: ScriptOutput -> Address

Computes a script address from a script output. This address can be used in a pay to script hash output.

sortMulSig :: ScriptOutput -> ScriptOutput

Sorts the public keys of a multisignature output in ascending order by comparing their serialized representations. This feature allows for easier multisignature account management as participants in a multisignature wallet will blindly agree on an ordering of the public keys without having to communicate.

Script Inputs

data ScriptInput

Constructors

RegularInput

Fields

getRegularInput :: SimpleInput

ScriptHashInput

Fields

getScriptHashInput :: SimpleInput

getScriptHashRedeem :: RedeemScript

Instances

Eq ScriptInput

Read ScriptInput

Show ScriptInput

NFData ScriptInput

data SimpleInput

Data type describing standard transaction input scripts. Input scripts provide the signing data required to unlock the coins of the output they are trying to spend.

Constructors

SpendPK

Spend the coins of a PayPK output.

Fields

getInputSig :: !TxSignature

SpendPKHash

Spend the coins of a PayPKHash output.

Fields

getInputSig :: !TxSignature

getInputKey :: !PubKey

SpendMulSig

Spend the coins of a PayMulSig output.

Fields

getInputMulSigKeys :: ![TxSignature]

Instances

Eq SimpleInput

Read SimpleInput

Show SimpleInput

NFData SimpleInput

type RedeemScript = ScriptOutput

encodeInput :: ScriptInput -> Script

encodeInputBS :: ScriptInput -> ByteString

Similar to encodeInput but encodes to a ByteString

decodeInput :: Script -> Either String ScriptInput

Decodes a ScriptInput from a Script. This function fails if the script can not be parsed as a standard script input.

decodeInputBS :: ByteString -> Either String ScriptInput

Similar to decodeInput but decodes from a ByteString

isSpendPK :: ScriptInput -> Bool

Returns True if the input script is spending a public key.

isSpendPKHash :: ScriptInput -> Bool

Returns True if the input script is spending a public key hash.

isSpendMulSig :: ScriptInput -> Bool

Returns True if the input script is spending a multisignature output.

isScriptHashInput :: ScriptInput -> Bool

Helpers

scriptRecipient :: Script -> Either String Address

Computes the recipient address of a script. This function fails if the script could not be decoded as a pay to public key hash or pay to script hash.

scriptSender :: Script -> Either String Address

Computes the sender address of a script. This function fails if the script could not be decoded as a spend public key hash or script hash input.

intToScriptOp :: Int -> ScriptOp

Transforms integers [1 .. 16] to ScriptOp [OP_1 .. OP_16]

scriptOpToInt :: ScriptOp -> Either String Int

Decode ScriptOp [OP_1 .. OP_16] to integers [1 .. 16]. This functions fails for other values of ScriptOp

SigHash

For additional information on sighashes, see: http://en.bitcoin.it/wiki/OP_CHECKSIG

data SigHash

Data type representing the different ways a transaction can be signed. When producing a signature, a hash of the transaction is used as the message to be signed. The SigHash parameter controls which parts of the transaction are used or ignored to produce the transaction hash. The idea is that if some part of a transaction is not used to produce the transaction hash, then you can change that part of the transaction after producing a signature without invalidating that signature.

If the anyoneCanPay flag is True, then only the current input is signed. Otherwise, all of the inputs of a transaction are signed. The default value for anyoneCanPay is False.

Constructors

SigAll

Sign all of the outputs of a transaction (This is the default value). Changing any of the outputs of the transaction will invalidate the signature.

Fields

anyoneCanPay :: !Bool

SigNone

Sign none of the outputs of a transaction. This allows anyone to change any of the outputs of the transaction.

Fields

anyoneCanPay :: !Bool

SigSingle

Sign only the output corresponding the the current transaction input. You care about your own output in the transaction but you don't care about any of the other outputs.

Fields

anyoneCanPay :: !Bool

SigUnknown

Unrecognized sighash types will decode to SigUnknown.

Fields

anyoneCanPay :: !Bool

getSigCode :: !Word8

Instances

Eq SigHash

Read SigHash

Show SigHash

ToJSON SigHash

FromJSON SigHash

Binary SigHash

NFData SigHash

txSigHash

Arguments

:: Tx

Transaction to sign.

-> Script

Output script that is being spent.

-> Int

Index of the input that is being signed.

-> SigHash

What parts of the transaction should be signed.

-> Word256

Result hash to be signed.

Computes the hash that will be used for signing a transaction.

encodeSigHash32 :: SigHash -> ByteString

Encodes a SigHash to a 32 bit-long bytestring.

isSigAll :: SigHash -> Bool

Returns True if the SigHash has the value SigAll.

isSigNone :: SigHash -> Bool

Returns True if the SigHash has the value SigNone.

isSigSingle :: SigHash -> Bool

Returns True if the SigHash has the value SigSingle.

isSigUnknown :: SigHash -> Bool

Returns True if the SigHash has the value SigUnknown.

data TxSignature

Data type representing a Signature together with a SigHash. The SigHash is serialized as one byte at the end of a regular ECDSA Signature. All signatures in transaction inputs are of type TxSignature.

Constructors

TxSignature

Fields

txSignature :: !Signature

sigHashType :: !SigHash

Instances

Eq TxSignature

Read TxSignature

Show TxSignature

NFData TxSignature

encodeSig :: TxSignature -> ByteString

Serialize a TxSignature to a ByteString.

decodeSig :: ByteString -> Either String TxSignature

Decode a TxSignature from a ByteString.

decodeCanonicalSig :: ByteString -> Either String TxSignature

Decode a TxSignature from a ByteString. This function will check if the signature is canonical and fail if it is not.

Evaluation

evalScript :: Script -> Script -> SigCheck -> Bool

verifySpend

Arguments

:: Tx

The spending transaction

-> Int

The input index

-> Script

The output script we are spending

-> Bool

Uses evalScript to check that the input script of a spending transaction satisfies the output script.

type SigCheck = [ScriptOp] -> TxSignature -> PubKey -> Bool

Defines the type of function required by script evaluating functions to check transaction signatures.