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JBaczuk / bitcoin-script-js

Bitcoin script interpreter written in javascript for browsers and node.js
MIT License
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Standard Bitcoin Script Assembly #19

Closed wardlem closed 5 years ago

wardlem commented 5 years ago

Is there a standard for how bitcoin script asm is supposed to be written? I have seen several different formats including:

OP_DUP OP_HASH160 ab68025513c3dbd2f7b92a94e0581f5d50f654e7 OP_EQUALVERIFY OP_CHECKSIG
OP_DUP OP_HASH160 [ab68025513c3dbd2f7b92a94e0581f5d50f654e7] OP_EQUALVERIFY OP_CHECKSIG
OP_DUP OP_HASH160 PUSHDATA(20)[ab68025513c3dbd2f7b92a94e0581f5d50f654e7] OP_EQUALVERIFY OP_CHECKSIG
OP_DUP OP_HASH160 0xab68025513c3dbd2f7b92a94e0581f5d50f654e7 OP_EQUALVERIFY OP_CHECKSIG

Additionally, does a literal 0 represent an OP_0 (empty array of bytes) or a literal 0.

JBaczuk commented 5 years ago

These are good questions. It depends on the platform. I think we should match how Bitcoin Core prints the assembly when you get a raw block or transaction.

JBaczuk commented 5 years ago

For the example above, it would look like this:

OP_DUP OP_HASH160 ab68025513c3dbd2f7b92a94e0581f5d50f654e7 OP_EQUALVERIFY OP_CHECKSIG

And a 0 can be either an OP_0 or a literal 0, but in order to push literal values to the stack, you first need a PUSH_DATA byte like 0x01 for 1 byte.

Example:

"asm": "0 30450221008d5ec57d362ff6ef6602e4e756ef1bdeee12bd5c5c72697ef1455b379c90531002202ef3ea04dfbeda043395e5bc701e4878c15baab9c6ba5808eb3d04c91f641a0c[ALL] 522103310188e911026cf18c3ce274e0ebb5f95b007f230d8cb7d09879d96dbeab1aff210243930746e6ed6552e03359db521b088134652905bd2d1541fa9124303a41e95621029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c7725553ae",
"hex": "004830450221008d5ec57d362ff6ef6602e4e756ef1bdeee12bd5c5c72697ef1455b379c90531002202ef3ea04dfbeda043395e5bc701e4878c15baab9c6ba5808eb3d04c91f641a0c014c69522103310188e911026cf18c3ce274e0ebb5f95b007f230d8cb7d09879d96dbeab1aff210243930746e6ed6552e03359db521b088134652905bd2d1541fa9124303a41e95621029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c7725553ae"