Exemplo n.º 1
0
// OP_CHECKSIG
// OP_CHECKSIGVERIFY
func execCheckSig(ctx *execContext, op Opcode, _ []byte) error {
	if ctx.stack.height() < 2 {
		return errStackItemMissing
	}
	pk := ctx.stack.pop()
	sig := ctx.stack.pop()
	subScript := make([]byte, len(ctx.script)-ctx.separator)
	copy(subScript, ctx.script[ctx.separator:])
	subScript, err := removeSig(subScript, sig)
	if err != nil {
		return err
	}
	err = checkKeySig(ctx.sctx, pk, sig, subScript, ctx.flags)
	if op == OP_CHECKSIGVERIFY {
		if err != nil {
			return errSigVerify
		}
	} else { // OP_CHECKSIG
		b := klib.ScriptInt(1)
		if err != nil {
			b = 0
		}
		ctx.stack.push(b.Bytes())
	}
	return nil
}
Exemplo n.º 2
0
func (s *Script) AppendPushInt(v int64) {
	if v == int64(OP_1NEGATE) || (v >= 1 && v <= 16) {
		s.AppendOp(Opcode(v + int64(OP_1) - 1))
	} else {
		i := klib.ScriptInt(v)
		s.AppendPushData(i.Bytes())
	}
}
Exemplo n.º 3
0
// OP_CHECKMULTISIG
// OP_CHECKMULTISIGVERIFY
func execCheckMultiSig(ctx *execContext, op Opcode, _ []byte) error {
	i := 1
	if ctx.stack.height() < i {
		return errStackItemMissing
	}
	kCount := int(klib.ToScriptInt(ctx.stack.top(-i)))
	if kCount < 0 || kCount > numbers.MaxMultiSigKeyCount {
		return errKeySigCountOutOfRange
	}
	ctx.opCount += kCount
	if ctx.opCount > numbers.MaxOpcodeCount {
		return errOpcodeCount
	}
	i++
	iKey := i
	i += kCount
	if ctx.stack.height() < i {
		return errStackItemMissing
	}
	sCount := int(klib.ToScriptInt(ctx.stack.top(-i)))
	if sCount < 0 || sCount > kCount {
		return errKeySigCountOutOfRange
	}
	i++
	iSig := i
	i += sCount
	if ctx.stack.height() < i {
		return errStackItemMissing
	}

	subScript := make([]byte, len(ctx.script)-ctx.separator)
	copy(subScript, ctx.script[ctx.separator:])
	for k := 0; k < sCount; k++ {
		var err error
		subScript, err = removeSig(subScript, ctx.stack.top(-(iSig + k)))
		if err != nil {
			return err
		}
	}
	success := true
	for success && (sCount > 0) {
		pk := ctx.stack.top(-iKey)
		sig := ctx.stack.top(-iSig)
		err := checkKeySig(ctx.sctx, pk, sig, subScript, ctx.flags)
		if err == nil {
			iSig++
			sCount--
		}
		iKey++
		kCount--
		// If there are more signatures left than keys left,
		// then too many signatures have failed
		if sCount > kCount {
			success = false
		}
	}

	// A Satoshi Bug causes CHECKMULTISIG to consume an extra item on the stack
	// We first clear all the "real" arguments
	stk := *ctx.stack
	*ctx.stack = stk[:len(stk)-i+1]
	// The dummy item is still requried
	if ctx.stack.empty() {
		return errStackItemMissing
	}
	// Now we check dummy being null when required
	si := ctx.stack.pop()
	if (ctx.flags&EvalFlagNullDummy) != 0 && len(si) > 0 {
		return errDummyArgNotNull
	}

	if op == OP_CHECKMULTISIGVERIFY {
		if !success {
			return errSigVerify
		}
	} else { // OP_CHECKMULTISIG
		b := klib.ScriptInt(1)
		if !success {
			b = 0
		}
		ctx.stack.push(b.Bytes())
	}
	return nil
}
Exemplo n.º 4
0
func intToStackItem(i int) stackItem {
	return klib.ScriptInt(i).Bytes()
}