Quote from: gigi0ne on Today at 09:59:21 PM

this is what they sent me

.To lock a transaction with this Script, do the following:

Serialize OP_ADD 99 OP_EQUAL:

* OP_ADD = 0x93 — a simple opcode translation
* 99 = 0x01, 0x63 — this opcode pushes one byte onto the stack, 99 (hex: 0x63)
* No worries about endian conversion because it's only one byte
* OP_EQUAL = 0x87 — a simple opcode translation
* <serialized99Equal> = "93016387"
$ btcc OP_ADD 99 OP_EQUAL
93016387

Save <serialized99Equal> for future reference as the redeemScript.

* <redeemScript> = "93016387"

SHA-256 and RIPEMD-160 hash the serialized script.

* <hashed99Equal> = "3f58b4f7b14847a9083694b9b3b52a4cea2569ed"

Produce a P2SH locking script that includes the <hashed99Equal>.

* scriptPubKey = "a9143f58b4f7b14847a9083694b9b3b52a4cea2569ed87"
You can then create a transaction using this scriptPubKey, probably via an API.

To unlock this transaction requires that the recipient produce a scriptSig that prepends two constants totalling ninety-nine to the serialized script: 1 98 <serialized99Equal>.

The process of unlocking the P2SH transaction then begins with a first round of validation, which checks that the redeem script matches the hashed value in the locking script.
Concatenate scriptSig and scriptPubKey and execute them, as normal:
Script: 1 98 <serialized99Equal> OP_HASH160 <hashed99Equal> OP_EQUAL
Stack: []

Script: 98 <serialized99Equal> OP_HASH160 <hashed99Equal> OP_EQUAL
Stack: [ 1 ]

Script: <serialized99Equal> OP_HASH160 <hashed99Equal> OP_EQUAL
Stack: [ 1 98 ]

Script: OP_HASH160 <hashed99Equal> OP_EQUAL
Stack: [ 1 98 <serialized99Equal> ]

Script: <hashed99Equal> OP_EQUAL
Running: <serialized99Equal> OP_HASH160
Stack: [ 1 98 <hashed99Equal> ]

Script: OP_EQUAL
Stack: [ 1 98 <hashed99Equal> <hashed99Equal> ]

Script:
Running: <hashed99Equal> <hashed99Equal> OP_EQUAL
Stack: [ 1 98 True ]
The Script ends with a True on top of the stack, and so it succeeds ... even though there's other cruft below it.
However, because this was a P2SH script, the execution isn't done.

For the second round of validation, verify that the values in the unlocking script satisfy the redeemScript: deserialize the redeemScript ("93016387" = "OP_ADD 99 OP_EQUAL"), then execute it using the items in the scriptSig prior to the serialized script:
Script: 1 98 OP_ADD 99 OP_EQUAL
Stack: [ ]

Script: 98 OP_ADD 99 OP_EQUAL
Stack: [ 1 ]

Script: OP_ADD 99 OP_EQUAL
Stack: [ 1 98 ]

Script: 99 OP_EQUAL
Running: 1 98 OP_ADD
Stack: [ 99 ]

Script: OP_EQUAL
Stack: [ 99 99 ]

Script:
Running: 99 99 OP_EQUAL
Stack: [ True ]
With that second validation also true, the UTXO can now be spent

The concept of Pay-to-Script-Hash (P2SH) did not exist in 2009. It was introduced to Bitcoin in 2012 as part of Bitcoin Improvement Proposal 16 (BIP16).