lbcd/txscript
Dave Collins d6b968c3ea
txscript: Refactor engine to use raw scripts.
This refactors the script engine to store and step through raw scripts
by making using of the new zero-allocation script tokenizer as opposed
to the less efficient method of storing and stepping through parsed
opcodes.  It also improves several aspects while refactoring such as
optimizing the disassembly trace, showing all scripts in the trace in
the case of execution failure, and providing additional comments
describing the purpose of each field in the engine.

It should be noted that this is a step towards removing the parsed
opcode struct and associated supporting code altogether, however, in
order to ease the review process, this retains the struct and all
function signatures for opcode execution which make use of an individual
parsed opcode.  Those will be updated in future commits.

The following is an overview of the changes:

- Modify internal engine scripts slice to use raw scripts instead of
  parsed opcodes
- Introduce a tokenizer to the engine to track the current script
- Remove no longer needed script offset parameter from the engine since
  that is tracked by the tokenizer
- Add an opcode index counter for disassembly purposes to the engine
- Update check for valid program counter to only consider the script
  index
  - Update tests for bad program counter accordingly
- Rework the NewEngine function
  - Store the raw scripts
  - Setup the initial tokenizer
  - Explicitly check against version 0 instead of DefaultScriptVersion
    which would break consensus if changed
  - Check the scripts parse according to version 0 semantics to retain
    current consensus rules
  - Improve comments throughout
- Rework the Step function
  - Use the tokenizer and raw scripts
  - Create a parsed opcode on the fly for now to retain existing
    opcode execution function signatures
  - Improve comments throughout
- Update the Execute function
  - Explicitly check against version 0 instead of DefaultScriptVersion
    which would break consensus if changed
  - Improve the disassembly tracing in the case of error
- Update the CheckErrorCondition function
  - Modify clean stack error message to make sense in all cases
  - Improve the comments
- Update the DisasmPC and DisasmScript functions on the engine
  - Use the tokenizer
  - Optimize construction via the use of strings.Builder
- Modify the subScript function to return the raw script bytes since the
  parsed opcodes are no longer stored
- Update the various signature checking opcodes to use the raw opcode
  data removal and signature hash calculation functions since the
  subscript is now a raw script
  - opcodeCheckSig
  - opcodeCheckMultiSig
  - opcodeCheckSigAlt
2021-11-16 18:49:08 -08:00
..
data txscript: Add benchmark for CalcSignatureHash 2021-11-16 18:45:14 -08:00
bench_test.go txscript: Add ExtractPkScriptAddrs benchmarks. 2021-11-16 18:47:59 -08:00
consensus.go txscript: Implement CheckSequenceVerify (BIP0112) 2016-10-19 12:06:44 -04:00
doc.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
engine.go txscript: Refactor engine to use raw scripts. 2021-11-16 18:49:08 -08:00
engine_test.go txscript: Refactor engine to use raw scripts. 2021-11-16 18:49:08 -08:00
error.go txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00
error_test.go txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00
example_test.go txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00
hashcache.go BIP0143+txscript: add segwit sighash, signing, and HashCache integration 2017-08-13 23:17:40 -05:00
hashcache_test.go txscript/hashcache_test: call rand.Seed once in init 2021-02-02 13:31:47 -08:00
log.go all: Remove seelog logger. 2017-06-19 16:46:50 -04:00
opcode.go txscript: Refactor engine to use raw scripts. 2021-11-16 18:49:08 -08:00
opcode_test.go txscript: Convert to use non-parsed opcode disasm. 2021-11-16 18:49:05 -08:00
pkscript.go txscript: refactor ComputePkScript 2019-06-03 13:55:28 -07:00
pkscript_test.go build: replace travis-ci with github actions. 2020-05-13 08:52:05 -04:00
README.md txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00
reference_test.go txscript/reference_test: Convert sighash calc test 2021-11-16 18:45:35 -08:00
script.go txscript: Use removeOpcodeRaw for CODESEP in calcSigHash 2021-11-16 18:48:52 -08:00
script_test.go txscript: Optimize removeOpcodeRaw 2021-11-16 18:48:47 -08:00
scriptbuilder.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
scriptbuilder_test.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
scriptnum.go txscript/scriptnum: add maxscriptnum and maxcltvlength 2021-11-16 18:47:54 -08:00
scriptnum_test.go txscript/scriptnum: add maxscriptnum and maxcltvlength 2021-11-16 18:47:54 -08:00
sigcache.go txscript: Drop the mutex before doing crypto 2017-01-31 13:47:41 -05:00
sigcache_test.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
sign.go txscript: Use raw scripts in SignTxOutput. 2021-11-16 18:48:42 -08:00
sign_test.go BIP0141+txscript: implement witness program validation 2017-08-13 23:17:40 -05:00
stack.go txscript/scriptnum: add maxscriptnum and maxcltvlength 2021-11-16 18:47:54 -08:00
stack_test.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
standard.go txscript: Optimize ExtractWitnessProgramInfo 2021-11-16 18:48:30 -08:00
standard_test.go txscript: Optimize CalcMultiSigStats. 2021-11-16 18:47:42 -08:00
tokenizer.go txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00
tokenizer_test.go txscript: Introduce zero-alloc script tokenizer. 2021-11-16 18:45:22 -08:00

txscript

Build Status ISC License GoDoc

Package txscript implements the bitcoin transaction script language. There is a comprehensive test suite.

This package has intentionally been designed so it can be used as a standalone package for any projects needing to use or validate bitcoin transaction scripts.

Bitcoin Scripts

Bitcoin provides a stack-based, FORTH-like language for the scripts in the bitcoin transactions. This language is not turing complete although it is still fairly powerful. A description of the language can be found at https://en.bitcoin.it/wiki/Script

Installation and Updating

$ go get -u github.com/btcsuite/btcd/txscript

Examples

GPG Verification Key

All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:

  • Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt

  • Import the public key into your GPG keyring:

    gpg --import GIT-GPG-KEY-conformal.txt
    
  • Verify the release tag with the following command where TAG_NAME is a placeholder for the specific tag:

    git tag -v TAG_NAME
    

License

Package txscript is licensed under the copyfree ISC License.