b871286f98
This refactors the script engine to store and step through raw scripts
by making using of the new zero-allocation script tokenizer as opposed
to the less efficient method of storing and stepping through parsed
opcodes. It also improves several aspects while refactoring such as
optimizing the disassembly trace, showing all scripts in the trace in
the case of execution failure, and providing additional comments
describing the purpose of each field in the engine.
It should be noted that this is a step towards removing the parsed
opcode struct and associated supporting code altogether, however, in
order to ease the review process, this retains the struct and all
function signatures for opcode execution which make use of an individual
parsed opcode. Those will be updated in future commits.
The following is an overview of the changes:
- Modify internal engine scripts slice to use raw scripts instead of
parsed opcodes
- Introduce a tokenizer to the engine to track the current script
- Remove no longer needed script offset parameter from the engine since
that is tracked by the tokenizer
- Add an opcode index counter for disassembly purposes to the engine
- Update check for valid program counter to only consider the script
index
- Update tests for bad program counter accordingly
- Rework the NewEngine function
- Store the raw scripts
- Setup the initial tokenizer
- Explicitly check against version 0 instead of DefaultScriptVersion
which would break consensus if changed
- Check the scripts parse according to version 0 semantics to retain
current consensus rules
- Improve comments throughout
- Rework the Step function
- Use the tokenizer and raw scripts
- Create a parsed opcode on the fly for now to retain existing
opcode execution function signatures
- Improve comments throughout
- Update the Execute function
- Explicitly check against version 0 instead of DefaultScriptVersion
which would break consensus if changed
- Improve the disassembly tracing in the case of error
- Update the CheckErrorCondition function
- Modify clean stack error message to make sense in all cases
- Improve the comments
- Update the DisasmPC and DisasmScript functions on the engine
- Use the tokenizer
- Optimize construction via the use of strings.Builder
- Modify the subScript function to return the raw script bytes since the
parsed opcodes are no longer stored
- Update the various signature checking opcodes to use the raw opcode
data removal and signature hash calculation functions since the
subscript is now a raw script
- opcodeCheckSig
- opcodeCheckMultiSig
- opcodeCheckSigAlt
428 lines
11 KiB
Go
428 lines
11 KiB
Go
// Copyright (c) 2013-2017 The btcsuite developers
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// Copyright (c) 2015-2019 The Decred developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package txscript
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import (
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"testing"
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"github.com/btcsuite/btcd/chaincfg/chainhash"
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"github.com/btcsuite/btcd/wire"
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)
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// TestBadPC sets the pc to a deliberately bad result then confirms that Step
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// and Disasm fail correctly.
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func TestBadPC(t *testing.T) {
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t.Parallel()
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tests := []struct {
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scriptIdx int
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}{
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{scriptIdx: 2},
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{scriptIdx: 3},
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}
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// tx with almost empty scripts.
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tx := &wire.MsgTx{
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Version: 1,
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TxIn: []*wire.TxIn{
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{
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PreviousOutPoint: wire.OutPoint{
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Hash: chainhash.Hash([32]byte{
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0xc9, 0x97, 0xa5, 0xe5,
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0x6e, 0x10, 0x41, 0x02,
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0xfa, 0x20, 0x9c, 0x6a,
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0x85, 0x2d, 0xd9, 0x06,
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0x60, 0xa2, 0x0b, 0x2d,
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0x9c, 0x35, 0x24, 0x23,
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0xed, 0xce, 0x25, 0x85,
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0x7f, 0xcd, 0x37, 0x04,
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}),
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Index: 0,
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},
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SignatureScript: mustParseShortForm("NOP"),
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Sequence: 4294967295,
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},
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},
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TxOut: []*wire.TxOut{{
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Value: 1000000000,
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PkScript: nil,
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}},
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LockTime: 0,
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}
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pkScript := mustParseShortForm("NOP")
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for _, test := range tests {
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vm, err := NewEngine(pkScript, tx, 0, 0, nil, nil, -1)
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if err != nil {
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t.Errorf("Failed to create script: %v", err)
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}
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// Set to after all scripts.
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vm.scriptIdx = test.scriptIdx
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// Ensure attempting to step fails.
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_, err = vm.Step()
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if err == nil {
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t.Errorf("Step with invalid pc (%v) succeeds!", test)
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continue
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}
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// Ensure attempting to disassemble the current program counter fails.
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_, err = vm.DisasmPC()
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if err == nil {
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t.Errorf("DisasmPC with invalid pc (%v) succeeds!", test)
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}
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}
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}
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// TestCheckErrorCondition tests the execute early test in CheckErrorCondition()
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// since most code paths are tested elsewhere.
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func TestCheckErrorCondition(t *testing.T) {
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t.Parallel()
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// tx with almost empty scripts.
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tx := &wire.MsgTx{
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Version: 1,
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TxIn: []*wire.TxIn{{
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PreviousOutPoint: wire.OutPoint{
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Hash: chainhash.Hash([32]byte{
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0xc9, 0x97, 0xa5, 0xe5,
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0x6e, 0x10, 0x41, 0x02,
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0xfa, 0x20, 0x9c, 0x6a,
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0x85, 0x2d, 0xd9, 0x06,
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0x60, 0xa2, 0x0b, 0x2d,
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0x9c, 0x35, 0x24, 0x23,
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0xed, 0xce, 0x25, 0x85,
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0x7f, 0xcd, 0x37, 0x04,
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}),
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Index: 0,
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},
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SignatureScript: nil,
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Sequence: 4294967295,
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}},
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TxOut: []*wire.TxOut{{
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Value: 1000000000,
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PkScript: nil,
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}},
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LockTime: 0,
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}
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pkScript := mustParseShortForm("NOP NOP NOP NOP NOP NOP NOP NOP NOP" +
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" NOP TRUE")
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vm, err := NewEngine(pkScript, tx, 0, 0, nil, nil, 0)
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if err != nil {
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t.Errorf("failed to create script: %v", err)
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}
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for i := 0; i < len(pkScript)-1; i++ {
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done, err := vm.Step()
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if err != nil {
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t.Fatalf("failed to step %dth time: %v", i, err)
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}
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if done {
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t.Fatalf("finshed early on %dth time", i)
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}
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err = vm.CheckErrorCondition(false)
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if !IsErrorCode(err, ErrScriptUnfinished) {
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t.Fatalf("got unexepected error %v on %dth iteration",
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err, i)
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}
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}
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done, err := vm.Step()
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if err != nil {
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t.Fatalf("final step failed %v", err)
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}
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if !done {
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t.Fatalf("final step isn't done!")
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}
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err = vm.CheckErrorCondition(false)
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if err != nil {
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t.Errorf("unexpected error %v on final check", err)
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}
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}
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// TestInvalidFlagCombinations ensures the script engine returns the expected
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// error when disallowed flag combinations are specified.
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func TestInvalidFlagCombinations(t *testing.T) {
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t.Parallel()
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tests := []ScriptFlags{
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ScriptVerifyCleanStack,
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}
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// tx with almost empty scripts.
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tx := &wire.MsgTx{
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Version: 1,
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TxIn: []*wire.TxIn{
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{
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PreviousOutPoint: wire.OutPoint{
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Hash: chainhash.Hash([32]byte{
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0xc9, 0x97, 0xa5, 0xe5,
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0x6e, 0x10, 0x41, 0x02,
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0xfa, 0x20, 0x9c, 0x6a,
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0x85, 0x2d, 0xd9, 0x06,
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0x60, 0xa2, 0x0b, 0x2d,
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0x9c, 0x35, 0x24, 0x23,
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0xed, 0xce, 0x25, 0x85,
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0x7f, 0xcd, 0x37, 0x04,
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}),
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Index: 0,
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},
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SignatureScript: []uint8{OP_NOP},
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Sequence: 4294967295,
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},
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},
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TxOut: []*wire.TxOut{
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{
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Value: 1000000000,
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PkScript: nil,
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},
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},
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LockTime: 0,
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}
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pkScript := []byte{OP_NOP}
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for i, test := range tests {
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_, err := NewEngine(pkScript, tx, 0, test, nil, nil, -1)
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if !IsErrorCode(err, ErrInvalidFlags) {
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t.Fatalf("TestInvalidFlagCombinations #%d unexpected "+
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"error: %v", i, err)
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}
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}
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}
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// TestCheckPubKeyEncoding ensures the internal checkPubKeyEncoding function
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// works as expected.
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func TestCheckPubKeyEncoding(t *testing.T) {
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t.Parallel()
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tests := []struct {
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name string
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key []byte
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isValid bool
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}{
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{
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name: "uncompressed ok",
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key: hexToBytes("0411db93e1dcdb8a016b49840f8c53bc1eb68" +
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"a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf" +
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"9744464f82e160bfa9b8b64f9d4c03f999b8643f656b" +
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"412a3"),
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isValid: true,
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},
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{
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name: "compressed ok",
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key: hexToBytes("02ce0b14fb842b1ba549fdd675c98075f12e9" +
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"c510f8ef52bd021a9a1f4809d3b4d"),
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isValid: true,
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},
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{
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name: "compressed ok",
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key: hexToBytes("032689c7c2dab13309fb143e0e8fe39634252" +
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"1887e976690b6b47f5b2a4b7d448e"),
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isValid: true,
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},
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{
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name: "hybrid",
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key: hexToBytes("0679be667ef9dcbbac55a06295ce870b07029" +
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"bfcdb2dce28d959f2815b16f81798483ada7726a3c46" +
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"55da4fbfc0e1108a8fd17b448a68554199c47d08ffb1" +
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"0d4b8"),
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isValid: false,
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},
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{
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name: "empty",
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key: nil,
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isValid: false,
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},
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}
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vm := Engine{flags: ScriptVerifyStrictEncoding}
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for _, test := range tests {
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err := vm.checkPubKeyEncoding(test.key)
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if err != nil && test.isValid {
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t.Errorf("checkSignatureEncoding test '%s' failed "+
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"when it should have succeeded: %v", test.name,
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err)
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} else if err == nil && !test.isValid {
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t.Errorf("checkSignatureEncooding test '%s' succeeded "+
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"when it should have failed", test.name)
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}
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}
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}
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// TestCheckSignatureEncoding ensures the internal checkSignatureEncoding
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// function works as expected.
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func TestCheckSignatureEncoding(t *testing.T) {
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t.Parallel()
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tests := []struct {
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name string
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sig []byte
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isValid bool
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}{
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{
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name: "valid signature",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: true,
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},
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{
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name: "empty.",
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sig: nil,
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isValid: false,
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},
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{
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name: "bad magic",
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sig: hexToBytes("314402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "bad 1st int marker magic",
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sig: hexToBytes("304403204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "bad 2nd int marker",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41032018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "short len",
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sig: hexToBytes("304302204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "long len",
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sig: hexToBytes("304502204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "long X",
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sig: hexToBytes("304402424e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "long Y",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022118152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "short Y",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41021918152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "trailing crap",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d0901"),
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isValid: false,
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},
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{
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name: "X == N ",
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sig: hexToBytes("30440220fffffffffffffffffffffffffffff" +
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"ffebaaedce6af48a03bbfd25e8cd0364141022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "X == N ",
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sig: hexToBytes("30440220fffffffffffffffffffffffffffff" +
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"ffebaaedce6af48a03bbfd25e8cd0364142022018152" +
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"2ec8eca07de4860a4acdd12909d831cc56cbbac46220" +
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"82221a8768d1d09"),
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isValid: false,
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},
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{
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name: "Y == N",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd410220fffff" +
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"ffffffffffffffffffffffffffebaaedce6af48a03bb" +
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"fd25e8cd0364141"),
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isValid: false,
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},
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{
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name: "Y > N",
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sig: hexToBytes("304402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd410220fffff" +
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"ffffffffffffffffffffffffffebaaedce6af48a03bb" +
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"fd25e8cd0364142"),
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isValid: false,
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},
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{
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name: "0 len X",
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sig: hexToBytes("302402000220181522ec8eca07de4860a4acd" +
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"d12909d831cc56cbbac4622082221a8768d1d09"),
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isValid: false,
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},
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{
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name: "0 len Y",
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sig: hexToBytes("302402204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd410200"),
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isValid: false,
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},
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{
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name: "extra R padding",
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sig: hexToBytes("30450221004e45e16932b8af514961a1d3a1a" +
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"25fdf3f4f7732e9d624c6c61548ab5fb8cd410220181" +
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"522ec8eca07de4860a4acdd12909d831cc56cbbac462" +
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"2082221a8768d1d09"),
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isValid: false,
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},
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{
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name: "extra S padding",
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sig: hexToBytes("304502204e45e16932b8af514961a1d3a1a25" +
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"fdf3f4f7732e9d624c6c61548ab5fb8cd41022100181" +
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"522ec8eca07de4860a4acdd12909d831cc56cbbac462" +
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"2082221a8768d1d09"),
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isValid: false,
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},
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}
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|
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vm := Engine{flags: ScriptVerifyStrictEncoding}
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for _, test := range tests {
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err := vm.checkSignatureEncoding(test.sig)
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if err != nil && test.isValid {
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t.Errorf("checkSignatureEncoding test '%s' failed "+
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"when it should have succeeded: %v", test.name,
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err)
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} else if err == nil && !test.isValid {
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t.Errorf("checkSignatureEncooding test '%s' succeeded "+
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"when it should have failed", test.name)
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}
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}
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}
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