BIP 16 changes (list inside)

Hi,

Is this an accurate and precise summary of the changes needed for P2SH and BIP 16?

== Block validation (starting with ProcessBlock) ==

* SigOpCount is now a LegacySigOpCount (CheckBlock)
* Main body of AcceptBlock() and rest of ProcessBlock() is unchanged.
* AddToBlockIndex() unchanged
* Some nice efficient improvements to SetBestChain(), but not related to BIP 16
* ConnectBlock() has new SigOp calculation.
* No important changes to FetchInputs()/ConnectInputs()

== Script ==

* Solver has special case to check for TX_SCRIPTHASH. Returns hash of input eval script * Another Solver which a) returns signature of pubkey script or b) TX_SCRIPTHASH - finds redeem script in KeyStore and returns it. * ExtractAddress(es) * VerifyScript: ** After running input script (scriptSig), copy stack ** Evaluate script as normal ** if block date (fValidatePayToScriptHash) and output script (scriptPubKey) is P2SH: *** scriptSig must be only push operations *** evaluate last item of copied stack as a script using the copied stack as the stack * SigOpCount (used inside CBlock::ConnectBlock main loop) does scoring checksigs and multisigs. ** Newly added DecodeOP_N to normal SigOpCount

== Address ==

* Set main hash160 data with a beginning byte (nVersion) of 0x05

On Sunday, March 18, 2012 10:04:27 AM Amir Taaki wrote:

> Is this an accurate and precise summary of the changes needed for P2SH and
> BIP 16?

You might find my 0.4.x backport helpful:
    https://github.com/luke-jr/bitcoin/commit/bip16_0.4.x
Be aware, this still needs auditing (nobody else has looked it over), but I
believe should cover only the minimal changes required to get P2SH validation
(though not the "standard" rule changes to accept them into blocks).