From b60e3547d2602b23fedf191d44377f3084f65a9a Mon Sep 17 00:00:00 2001
From: Dave Collins <davec@conformal.com>
Date: Wed, 19 Oct 2016 22:50:53 -0500
Subject: [PATCH] txscript: Correct nulldata standardness check.
This corrects the isNullData standard transaction type test to work
properly with canonically-encoded data pushes. In particular, single
byte data pushes that are small integers (0-16) are converted to the
equivalent numeric opcodes when canonically encoded and the code failed
to detect them properly.
It also adds several tests to ensure that both canonical and
non-canonical nulldata scripts are recognized properly and modifies the
test failure print to include the script that failed.
This does not affect consensus since it is just a standardness check.
---
txscript/standard.go | 3 +-
txscript/standard_test.go | 71 ++++++++++++++++++++++++++++-----------
2 files changed, 53 insertions(+), 21 deletions(-)
diff --git a/txscript/standard.go b/txscript/standard.go
index 921208f1..f64ff099 100644
--- a/txscript/standard.go
+++ b/txscript/standard.go
@@ -138,7 +138,8 @@ func isNullData(pops []parsedOpcode) bool {
return l == 2 &&
pops[0].opcode.value == OP_RETURN &&
- pops[1].opcode.value <= OP_PUSHDATA4 &&
+ (isSmallInt(pops[1].opcode) || pops[1].opcode.value <=
+ OP_PUSHDATA4) &&
len(pops[1].data) <= MaxDataCarrierSize
}
diff --git a/txscript/standard_test.go b/txscript/standard_test.go
index a7f74165..09ab135a 100644
--- a/txscript/standard_test.go
+++ b/txscript/standard_test.go
@@ -804,19 +804,15 @@ func TestCalcMultiSigStats(t *testing.T) {
}
}
-// scriptClassTest houses a test used to ensure various scripts have the
-// expected class.
-type scriptClassTest struct {
- name string
- script string
- class txscript.ScriptClass
-}
-
// scriptClassTests houses several test scripts used to ensure various class
// determination is working as expected. It's defined as a test global versus
// inside a function scope since this spans both the standard tests and the
// consensus tests (pay-to-script-hash is part of consensus).
-var scriptClassTests = []scriptClassTest{
+var scriptClassTests = []struct {
+ name string
+ script string
+ class txscript.ScriptClass
+}{
{
name: "Pay Pubkey",
script: "DATA_65 0x0411db93e1dcdb8a016b49840f8c53bc1eb68a382e" +
@@ -847,21 +843,56 @@ var scriptClassTests = []scriptClassTest{
"9ae88 EQUAL",
class: txscript.ScriptHashTy,
},
+
{
// Nulldata with no data at all.
- name: "nulldata",
+ name: "nulldata no data",
script: "RETURN",
class: txscript.NullDataTy,
},
{
- // Nulldata with small data.
- name: "nulldata2",
+ // Nulldata with single zero push.
+ name: "nulldata zero",
+ script: "RETURN 0",
+ class: txscript.NullDataTy,
+ },
+ {
+ // Nulldata with small integer push.
+ name: "nulldata small int",
+ script: "RETURN 1",
+ class: txscript.NullDataTy,
+ },
+ {
+ // Nulldata with max small integer push.
+ name: "nulldata max small int",
+ script: "RETURN 16",
+ class: txscript.NullDataTy,
+ },
+ {
+ // Nulldata with small data push.
+ name: "nulldata small data",
script: "RETURN DATA_8 0x046708afdb0fe554",
class: txscript.NullDataTy,
},
{
- // Nulldata with max allowed data.
- name: "nulldata3",
+ // Canonical nulldata with 60-byte data push.
+ name: "canonical nulldata 60-byte push",
+ script: "RETURN 0x3c 0x046708afdb0fe5548271967f1a67130b7105cd" +
+ "6a828e03909a67962e0ea1f61deb649f6bc3f4cef3046708afdb" +
+ "0fe5548271967f1a67130b7105cd6a",
+ class: txscript.NullDataTy,
+ },
+ {
+ // Non-canonical nulldata with 60-byte data push.
+ name: "non-canonical nulldata 60-byte push",
+ script: "RETURN PUSHDATA1 0x3c 0x046708afdb0fe5548271967f1a67" +
+ "130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3" +
+ "046708afdb0fe5548271967f1a67130b7105cd6a",
+ class: txscript.NullDataTy,
+ },
+ {
+ // Nulldata with max allowed data to be considered standard.
+ name: "nulldata max standard push",
script: "RETURN PUSHDATA1 0x50 0x046708afdb0fe5548271967f1a67" +
"130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3" +
"046708afdb0fe5548271967f1a67130b7105cd6a828e03909a67" +
@@ -869,9 +900,9 @@ var scriptClassTests = []scriptClassTest{
class: txscript.NullDataTy,
},
{
- // Nulldata with more than max allowed data (so therefore
- // nonstandard)
- name: "nulldata4",
+ // Nulldata with more than max allowed data to be considered
+ // standard (so therefore nonstandard)
+ name: "nulldata exceed max standard push",
script: "RETURN PUSHDATA1 0x51 0x046708afdb0fe5548271967f1a67" +
"130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3" +
"046708afdb0fe5548271967f1a67130b7105cd6a828e03909a67" +
@@ -881,7 +912,7 @@ var scriptClassTests = []scriptClassTest{
{
// Almost nulldata, but add an additional opcode after the data
// to make it nonstandard.
- name: "nulldata5",
+ name: "almost nulldata",
script: "RETURN 4 TRUE",
class: txscript.NonStandardTy,
},
@@ -951,8 +982,8 @@ func TestScriptClass(t *testing.T) {
script := mustParseShortForm(test.script)
class := txscript.GetScriptClass(script)
if class != test.class {
- t.Errorf("%s: expected %s got %s", test.name,
- test.class, class)
+ t.Errorf("%s: expected %s got %s (script %x)", test.name,
+ test.class, class, script)
return
}
}