60 lines
2.4 KiB
Go
60 lines
2.4 KiB
Go
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// Copyright (c) 2013 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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/*
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Package btcscript implements bitcoin transaction scripts.
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A complete description of the script language used by bitcoin can be found at
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https://en.bitcoin.it/wiki/Script. The following only serves as a quick
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overview to provide information on how to use the package.
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This package provides data structures and functions to parse and execute
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bitcoin transaction scripts.
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Script Overview
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Bitcoin transaction scripts are written in a stack-base, FORTH-like language.
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The bitcoin script language consists of a number of opcodes which fall into
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several categories such pushing and popping data to and from the stack,
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performing basic and bitwise arithmetic, conditional branching, comparing
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hashes, and checking cryptographic signatures. Scripts are processed from left
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to right and intentionally do not provide loops.
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The vast majority of Bitcoin scripts at the time of this writing are of several
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standard forms which consist of a spender providing a public key and a signature
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which proves the spender owns the associated private key. This information
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is used to prove the the spender is authorized to perform the transaction.
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One benefit of using a scripting language is added flexibility in specifying
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what conditions must be met in order to spend bitcoins.
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Usage
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The usage of this package consists of creating a new script engine for a pair
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of transaction inputs and outputs and using the engine to execute the scripts.
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The following function is an example of how to create and execute a script
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engine to validate a transaction.
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// ValidateTx validates the txIdx'th input of tx. The output transaction
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// corresponding to the this input is the txInIdx'th output of txIn. The
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// block timestamp of tx is timestamp and the protocol version involved
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// is pver.
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func ValidateTx(tx *btcwire.MsgTx, txIdx int, txIn *btcwire.MsgTx, txInIdx int, pver int, timestamp time.Time) {
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pkScript := txIn.TxOut[txInIdx].PkScript
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sigScript := tx.txIn[TxIdx]
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engine, err := btcscript.NewScript(sigScript, pkScript, txInIdx,
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tx, pver, timestamp.After(btcscript.Bip16Activation))
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return engine.Execute()
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}
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Errors
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Errors returned by this package are of the form btcscript.StackErrX where X
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indicates the specific error. See Variables in the package documentation for a
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full list.
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*/
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package btcscript
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