bitcoin/bips
1
0
Fork 0
mirror of https://github.com/bitcoin/bips.git synced 2026-03-30 16:06:44 +00:00
Code Issues Releases Wiki Activity

Remove P2SH support

Browse Source
This commit is contained in:
Pieter Wuille
2019-09-20 16:14:25 -07:00
parent 8ea6798a9d
commit 972136beb6
2 changed files with 16 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
bip-tapscript.mediawiki
View File

@@ -44,8 +44,8 @@ Additionally, the new tapscript <code>OP_SUCCESS</code> opcodes allow introducin
==Specification==
The rules below only apply when validating a transaction input for which all of the conditions below are true:
* The transaction output is a '''segregated witness spend''' (i.e., either the scriptPubKey or BIP16 redeemScript is a witness program as defined in BIP141).
* It is a '''taproot spend''' as defined in bip-taproot (i.e., the witness version is 1, the witness program is 32 bytes).
* The transaction output is a '''segregated witness spend''' (i.e., the scriptPubKey is a witness program as defined in BIP141).
* It is a '''taproot spend''' as defined in bip-taproot (i.e., the witness version is 1, the witness program is 32 bytes, and it is not P2SH wrapped).
* It is a '''script path spend''' as defined in bip-taproot (i.e., after removing the optional annex from the witness stack, two or more stack elements remain).
* The leaf version is ''0xc0'' (i.e. the first byte of the last witness element after removing the optional annex is ''0xc0'')<ref>'''How is the ''0xc0'' constant chosen?''' Following the guidelines in bip-taproot, by choosing a value having the two top bits set, tapscript spends are identifiable even without access to the UTXO being spent.</ref>, marking it as a '''tapscript spend'''.
@@ -103,10 +103,9 @@ These opcodes count toward the 201 non-push opcodes limit.
As the message for signature opcodes signature verification, transaction digest has the same definition as in bip-taproot, except the following:
The one-byte <code>spend_type</code> has a different value, specificially at bit-2:
* Bit-0 is set if the <code>scriptPubKey</code> being spent is P2SH (opposed to "native segwit").
* Bit-1 is set if an annex is present (the original witness stack has at least two witness elements, and the first byte of the last element is <code>0x50</code>).
* Bit-2 is set.
The one-byte <code>spend_type</code> has a different value, specificially at bit 1:
* Bit 0 is set if an annex is present (the original witness stack has at least two witness elements, and the first byte of the last element is <code>0x50</code>).
* Bit 1 is set.
* The other bits are unset.
As additional pieces of data, added at the end of the input to the ''hash<sub>TapSighash</sub>'' function:
@@ -114,7 +113,7 @@ As additional pieces of data, added at the end of the input to the ''hash<sub>Ta
* <code>key_version</code> (1): a constant value <code>0x00</code> representing the current version of public keys in the tapscript signature opcode execution.
* <code>codeseparator_position</code> (2): the opcode position of the last executed <code>OP_CODESEPARATOR</code> before the currently executed signature opcode, with the value in little endian (or <code>0xffff</code> if none executed). The first opcode in a script has a position of 0. A multi-byte push opcode is counted as one opcode, regardless of the size of data being pushed.
The total number of bytes hashed is at most ''244''<ref>'''What is the number of bytes hashed for the signature hash?''' The total size of the input to ''hash<sub>TapSighash</sub>'' (excluding the initial 64-byte hash tag) can be computed using the following formula: ''211 - is_anyonecanpay * 50 - is_none * 32 - is_p2sh_spending * 11 + has_annex * 32''.</ref>.
The total number of bytes hashed is at most ''244''<ref>'''What is the number of bytes hashed for the signature hash?''' The total size of the input to ''hash<sub>TapSighash</sub>'' (excluding the initial 64-byte hash tag) can be computed using the following formula: ''211 - is_anyonecanpay * 50 - is_none * 32 + has_annex * 32''.</ref>.
In summary, the semantics of the BIP143 sighash types remain unchanged, except the following:
# The exceptions mentioned in bip-taproot.