lbcd/txscript
Dave Collins 34ebf0f32f
txscript: Optimize IsMultisigSigScript.
This converts the IsMultisigSigScript function to analyze the raw script
and make use of the new tokenizer instead of the far less efficient
parseScript thereby significantly optimizing the function.

In order to accomplish this, it first rejects scripts that can't
possibly fit the bill due to the final byte of what would be the redeem
script not being the appropriate opcode or the overall script not having
enough bytes.  Then, it uses a new function that is introduced named
finalOpcodeData that uses the tokenizer to return any data associated
with the final opcode in the signature script (which will be nil for
non-push opcodes or if the script fails to parse) and analyzes it as if
it were a redeem script when it is non nil.

It is also worth noting that this new implementation intentionally has
the same semantic difference from the existing implementation as the
updated IsMultisigScript function in regards to allowing zero pubkeys
whereas previously it incorrectly required at least one pubkey.

Finally, the comment is modified to explicitly call out the script
version semantics.

The following is a before and after comparison of analyzing a large
script that is not a multisig script and both a 1-of-2 multisig public
key script (which should be false) and a signature script comprised of a
pay-to-script-hash 1-of-2 multisig redeem script (which should be true):

benchmark                               old ns/op     new ns/op     delta
BenchmarkIsMultisigSigScriptLarge-8     69328         2.93          -100.00%
BenchmarkIsMultisigSigScript-8          2375          146           -93.85%

benchmark                               old allocs     new allocs     delta
BenchmarkIsMultisigSigScriptLarge-8     5              0              -100.00%
BenchmarkIsMultisigSigScript-8          3              0              -100.00%

benchmark                               old bytes     new bytes     delta
BenchmarkIsMultisigSigScriptLarge-8     330035        0             -100.00%
BenchmarkIsMultisigSigScript-8          9472          0             -100.00%
2021-11-16 18:46:03 -08:00
..
data txscript: Add benchmark for CalcSignatureHash 2021-11-16 18:45:14 -08:00
bench_test.go txscript: Add benchmarks for IsMutlsigSigScript. 2021-11-16 18:46:01 -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: Optimize IsMultisigScript. 2021-11-16 18:45:59 -08:00
engine_test.go BIP0141+txscript: implement witness program validation 2017-08-13 23:17:40 -05:00
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: Introduce raw script sighash calc func. 2021-11-16 18:45:29 -08:00
opcode_test.go build: clean linter warnings 2020-05-13 08:58:39 -04:00
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: Optimize IsMultisigSigScript. 2021-11-16 18:46:03 -08:00
script_test.go txscript: add benchmark for IsUnspendable 2021-02-02 09:20:31 -05:00
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: Significantly improve errors. 2017-01-12 13:12:39 -06:00
scriptnum_test.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
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: Introduce raw script sighash calc func. 2021-11-16 18:45:29 -08:00
sign_test.go BIP0141+txscript: implement witness program validation 2017-08-13 23:17:40 -05:00
stack.go multi: Simplify code per gosimple linter. 2017-03-22 15:34:13 -05:00
stack_test.go txscript: Significantly improve errors. 2017-01-12 13:12:39 -06:00
standard.go txscript: Optimize IsMultisigSigScript. 2021-11-16 18:46:03 -08:00
standard_test.go rpcclient: implement getaddressinfo command 2020-09-21 09:47:58 -04:00
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.