ScriptSignature from P2WSH Witness #1605
Conversation
| @@ -106,6 +110,21 @@ sealed abstract class P2WSHWitnessV0 extends ScriptWitnessV0 { | |||
| relevantStack.map(ECDigitalSignature.fromBytes) | |||
| } | |||
|
|
|||
| // Note that this is not guaranteed to work for non-standard script signatures | |||
| lazy val scriptSignature: ScriptSignature = { | |||
There was a problem hiding this comment.
Should this be an Option[ScriptSignature]?
This throws on the case where the stack is empty (.tail)
There was a problem hiding this comment.
Upon further evaluation, I believe that this actually does work in all cases, and the thing that doesn't work is the apply method below which takes in a ScriptSignature (which will fail to act as expected if there's anything other than push ops). So no Option, but you're right that we should require that there be a redeem script (i.e. stack.nonEmpty) at the top of this trait
| lazy val scriptSignature: ScriptSignature = { | ||
| val asm = stack.toVector.tail.reverse.flatMap { bytes => | ||
| if (bytes.isEmpty) { | ||
| Vector(OP_0) |
There was a problem hiding this comment.
Why OP_0 if there is nothing on the stack?
There was a problem hiding this comment.
Not nothing on the stack, an empty element on the stack (a Script zero)
| val asm = stack.toVector.tail.reverse.flatMap { bytes => | ||
| if (bytes.isEmpty) { | ||
| Vector(OP_0) | ||
| } else if (bytes.length == 1 && bytes.head <= 16 && bytes.head >= -1) { |
There was a problem hiding this comment.
Maybe just
val numOpt = bytes.headOption.flatMap(byte => ScriptNumberOperation.fromNumber(byte))
...
else if (numOpt.isDefined)) {
Vector(numOpt.get)
}
...There was a problem hiding this comment.
I personally like how it is because it clearly enumerates all cases
Added method to pull script signature out of P2WSH witness