Add flag bitmask to NewScript for canonical sig checks.

This removes the bip16 bool from NewScript and adds it to flags (with
the constant ScriptBip16), and also adds a new flag,
ScriptCanonicalSignatures, which will call btcec.ParseDERSignature
parsing a signature during an Execute.  This is needed to emulate
bitcoind behavior, as bitcoind performs canonical signature validation
(DER format) in some places (like mempool acceptance) but not others
(like block validation).

Updated tests and test coverage file to reflect changes.

opcode.go

@@ -1682,7 +1682,12 @@ func opcodeCheckSig(op *parsedOpcode, s *Script) error {
 		return err
 	}
 
-	signature, err := btcec.ParseSignature(sigStr, btcec.S256())
+	var signature *btcec.Signature
+	if s.der {
+		signature, err = btcec.ParseDERSignature(sigStr, btcec.S256())
+	} else {
+		signature, err = btcec.ParseSignature(sigStr, btcec.S256())
+	}
 	if err != nil {
 		log.Warnf("can't parse signature from string: %v", err)
 		return err
@@ -1761,10 +1766,17 @@ func opcodeCheckMultiSig(op *parsedOpcode, s *Script) error {
 			return err
 		}
 		// skip off the last byte for hashtype
+		if s.der {
+			signatures[i], err =
+				btcec.ParseDERSignature(
+					sigStrings[i][:len(sigStrings[i])-1],
+					btcec.S256())
+		} else {
 			signatures[i], err =
 				btcec.ParseSignature(
 					sigStrings[i][:len(sigStrings[i])-1],
 					btcec.S256())
+		}
 		if err != nil {
 			return err
 		}

opcode_test.go

@@ -19,6 +19,7 @@ import (
 // All run on a fake tx with a single in, single out.
 type opcodeTest struct {
 	script     []byte
+	canonical  bool
 	shouldPass bool
 	shouldFail error
 }
@@ -384,6 +385,18 @@ var opcodeTests = []opcodeTest{
 		0x8a, 0x06, 0x26, 0xf1, 0xba, 0xde, 0xd5, 0xc7, 0x2a, 0x70,
 		0x4f, 0x7e, 0x6c, 0xd8, 0x4c,
 		btcscript.OP_1, btcscript.OP_CHECK_MULTISIG},
+		canonical:  false,
+		shouldPass: false},
+	{script: []byte{btcscript.OP_1, btcscript.OP_1, btcscript.OP_DATA_65,
+		0x04, 0xae, 0x1a, 0x62, 0xfe, 0x09, 0xc5, 0xf5, 0x1b, 0x13,
+		0x90, 0x5f, 0x07, 0xf0, 0x6b, 0x99, 0xa2, 0xf7, 0x15, 0x9b,
+		0x22, 0x25, 0xf3, 0x74, 0xcd, 0x37, 0x8d, 0x71, 0x30, 0x2f,
+		0xa2, 0x84, 0x14, 0xe7, 0xaa, 0xb3, 0x73, 0x97, 0xf5, 0x54,
+		0xa7, 0xdf, 0x5f, 0x14, 0x2c, 0x21, 0xc1, 0xb7, 0x30, 0x3b,
+		0x8a, 0x06, 0x26, 0xf1, 0xba, 0xde, 0xd5, 0xc7, 0x2a, 0x70,
+		0x4f, 0x7e, 0x6c, 0xd8, 0x4c,
+		btcscript.OP_1, btcscript.OP_CHECK_MULTISIG},
+		canonical:  true,
 		shouldPass: false},
 	/* up here because no defined error case. */
 	{script: []byte{btcscript.OP_1, btcscript.OP_1, btcscript.OP_DATA_65,
@@ -468,7 +481,7 @@ var opcodeTests = []opcodeTest{
 	{script: []byte{252}, shouldPass: false},
 }
 
-func testScript(t *testing.T, script []byte) (err error) {
+func testScript(t *testing.T, script []byte, canonical bool) (err error) {
 	// mock up fake tx.
 	tx := &btcwire.MsgTx{
 		Version: 1,
@@ -493,8 +506,13 @@ func testScript(t *testing.T, script []byte) (err error) {
 
 	tx.TxOut[0].PkScript = script
 
+	var flags btcscript.ScriptFlags
+	if canonical {
+		flags = btcscript.ScriptCanonicalSignatures
+	}
+
 	engine, err := btcscript.NewScript(tx.TxIn[0].SignatureScript,
-		tx.TxOut[0].PkScript, 0, tx, false)
+		tx.TxOut[0].PkScript, 0, tx, flags)
 	if err != nil {
 		return err
 	}
@@ -514,7 +532,7 @@ func TestScripts(t *testing.T) {
 	for i := range opcodeTests {
 		shouldPass := opcodeTests[i].shouldPass
 		shouldFail := opcodeTests[i].shouldFail
-		err := testScript(t, opcodeTests[i].script)
+		err := testScript(t, opcodeTests[i].script, opcodeTests[i].canonical)
 		if shouldFail != nil {
 			if err == nil {
 				t.Errorf("test %d passed should fail with %v", i, err)
@@ -4279,7 +4297,7 @@ func testOpcode(t *testing.T, test *detailedTest) {
 	tx.TxOut[0].PkScript = test.script
 
 	engine, err := btcscript.NewScript(tx.TxIn[0].SignatureScript,
-		tx.TxOut[0].PkScript, 0, tx, false)
+		tx.TxOut[0].PkScript, 0, tx, 0)
 	if err != nil {
 		if err != test.expectedReturn {
 			t.Errorf("Error return not expected %s: %v %v",

script.go

@@ -159,6 +159,7 @@ type Script struct {
 	condStack       []int
 	numOps          int
 	bip16           bool     // treat execution as pay-to-script-hash
+	der             bool     // enforce DER encoding
 	savedFirstStack [][]byte // stack from first script for bip16 scripts
 }
 
@@ -361,11 +362,35 @@ func unparseScript(pops []parsedOpcode) ([]byte, error) {
 	return script, nil
 }
 
+// ScriptFlags is a bitmask defining additional operations or
+// tests that will be done when executing a Script.
+type ScriptFlags uint32
+
+const (
+	// ScriptBip16 defines whether the bip16 threshhold has passed and thus
+	// pay-to-script hash transactions will be fully validated.
+	ScriptBip16 ScriptFlags = 1 << iota
+
+	// ScriptCanonicalSignatures defines whether additional canonical
+	// signature checks are performed when parsing a signature.
+	//
+	// Canonical (DER) signatures are not required in the tx rules for
+	// block acceptance, but are checked in recent versions of bitcoind
+	// when accepting transactions to the mempool.  Non-canonical (valid
+	// BER but not valid DER) transactions can potentially be changed
+	// before mined into a block, either by adding extra padding or
+	// flipping the sign of the R or S value in the signature, creating a
+	// transaction that still validates and spends the inputs, but is not
+	// recognized by creator of the transaction.  Performing a canonical
+	// check enforces script signatures use a unique DER format.
+	ScriptCanonicalSignatures
+)
+
 // NewScript returns a new script engine for the provided tx and input idx with
 // a signature script scriptSig and a pubkeyscript scriptPubKey. If bip16 is
 // true then it will be treated as if the bip16 threshhold has passed and thus
 // pay-to-script hash transactions will be fully validated.
-func NewScript(scriptSig []byte, scriptPubKey []byte, txidx int, tx *btcwire.MsgTx, bip16 bool) (*Script, error) {
+func NewScript(scriptSig []byte, scriptPubKey []byte, txidx int, tx *btcwire.MsgTx, flags ScriptFlags) (*Script, error) {
 	var m Script
 	scripts := [][]byte{scriptSig, scriptPubKey}
 	m.scripts = make([][]parsedOpcode, len(scripts))
@@ -385,6 +410,8 @@ func NewScript(scriptSig []byte, scriptPubKey []byte, txidx int, tx *btcwire.Msg
 		}
 	}
 
+	// Parse flags.
+	bip16 := flags&ScriptBip16 == ScriptBip16
 	if bip16 && isScriptHash(m.scripts[1]) {
 		// if we are pay to scripthash then we only accept input
 		// scripts that push data
@@ -393,6 +420,9 @@ func NewScript(scriptSig []byte, scriptPubKey []byte, txidx int, tx *btcwire.Msg
 		}
 		m.bip16 = true
 	}
+	if flags&ScriptCanonicalSignatures == ScriptCanonicalSignatures {
+		m.der = true
+	}
 
 	m.tx = *tx
 	m.txidx = txidx
@@ -964,19 +994,39 @@ func signatureScriptCustomReader(reader io.Reader, tx *btcwire.MsgTx, idx int,
 //
 //  0x30 <length> 0x02 <length r> r 0x02 <length s> s
 func sigDER(r, s *big.Int) []byte {
+	// In DER format, a leading 0x00 octet must be prepended to
+	// the byte slice so it cannot be interpreted as a negative
+	// big-endian number.  This is only done if the sign bit on
+	// the first byte is set.
+	var rb, sb []byte
+	if r.Bytes()[0]&0x80 != 0 {
+		paddedBytes := make([]byte, len(r.Bytes())+1)
+		copy(paddedBytes[1:], r.Bytes())
+		rb = paddedBytes
+	} else {
+		rb = r.Bytes()
+	}
+	if s.Bytes()[0]&0x80 != 0 {
+		paddedBytes := make([]byte, len(s.Bytes())+1)
+		copy(paddedBytes[1:], s.Bytes())
+		sb = paddedBytes
+	} else {
+		sb = s.Bytes()
+	}
+
 	// total length of returned signature is 1 byte for each magic and
 	// length (6 total), plus lengths of r and s
-	length := 6 + len(r.Bytes()) + len(s.Bytes())
+	length := 6 + len(rb) + len(sb)
 	b := make([]byte, length, length)
 
 	b[0] = 0x30
 	b[1] = byte(length - 2)
 	b[2] = 0x02
-	b[3] = byte(len(r.Bytes()))
+	b[3] = byte(len(rb))
-	offset := copy(b[4:], r.Bytes()) + 4
+	offset := copy(b[4:], rb) + 4
 	b[offset] = 0x02
-	b[offset+1] = byte(len(s.Bytes()))
+	b[offset+1] = byte(len(sb))
-	copy(b[offset+2:], s.Bytes())
+	copy(b[offset+2:], sb)
 	return b
 }
 

script_test.go

@@ -20,6 +20,7 @@ type txTest struct {
 	pkScript      []byte               // output script of previous tx
 	idx           int                  // tx idx to be run.
 	bip16         bool                 // is bip16 active?
+	canonicalSigs bool                 // should signatures be validated as canonical?
 	parseErr      error                // failure of NewScript
 	err           error                // Failure of Executre
 	shouldFail    bool                 // Execute should fail with nonspecified error.
@@ -566,6 +567,178 @@ var txTests = []txTest{
 			SigOps:         1,
 		},
 	},
+	txTest{
+		name: "Non-canonical signature: R value negative",
+		tx: &btcwire.MsgTx{
+			Version: 1,
+			TxIn: []*btcwire.TxIn{
+				&btcwire.TxIn{
+					PreviousOutpoint: btcwire.OutPoint{
+						Hash: btcwire.ShaHash([32]byte{
+							0xfe, 0x15, 0x62, 0xc4,
+							0x8b, 0x3a, 0xa6, 0x37,
+							0x3f, 0x42, 0xe9, 0x61,
+							0x51, 0x89, 0xcf, 0x73,
+							0x32, 0xd7, 0x33, 0x5c,
+							0xbe, 0xa7, 0x80, 0xbe,
+							0x69, 0x6a, 0xc6, 0xc6,
+							0x50, 0xfd, 0xda, 0x4a,
+						}),
+						Index: 1,
+					},
+					SignatureScript: []byte{
+						btcscript.OP_DATA_71,
+						0x30, 0x44, 0x02, 0x20, 0xa0,
+						0x42, 0xde, 0xe5, 0x52, 0x6b,
+						0xf2, 0x29, 0x4d, 0x3f, 0x3e,
+						0xb9, 0x5a, 0xa7, 0x73, 0x19,
+						0xd3, 0xff, 0x56, 0x7b, 0xcf,
+						0x36, 0x46, 0x07, 0x0c, 0x81,
+						0x12, 0x33, 0x01, 0xca, 0xce,
+						0xa9, 0x02, 0x20, 0xea, 0x48,
+						0xae, 0x58, 0xf5, 0x54, 0x10,
+						0x96, 0x3f, 0xa7, 0x03, 0xdb,
+						0x56, 0xf0, 0xba, 0xb2, 0x70,
+						0xb1, 0x08, 0x22, 0xc5, 0x1c,
+						0x68, 0x02, 0x6a, 0x97, 0x5c,
+						0x7d, 0xae, 0x11, 0x2e, 0x4f,
+						0x01,
+						btcscript.OP_DATA_65,
+						0x04, 0x49, 0x45, 0x33, 0x18,
+						0xbd, 0x5e, 0xcf, 0xea, 0x5f,
+						0x86, 0x32, 0x8c, 0x6d, 0x8e,
+						0xd4, 0x12, 0xb4, 0xde, 0x2c,
+						0xab, 0xd7, 0xb8, 0x56, 0x51,
+						0x2f, 0x8c, 0xb7, 0xfd, 0x25,
+						0xf6, 0x03, 0xb0, 0x55, 0xc5,
+						0xdf, 0xe6, 0x22, 0x4b, 0xc4,
+						0xfd, 0xbb, 0x6a, 0x7a, 0xa0,
+						0x58, 0xd7, 0x5d, 0xad, 0x92,
+						0x99, 0x45, 0x4f, 0x62, 0x1a,
+						0x95, 0xb4, 0xb0, 0x21, 0x0e,
+						0xc4, 0x09, 0x2b, 0xe5, 0x27,
+					},
+					Sequence: 4294967295,
+				},
+				&btcwire.TxIn{
+					PreviousOutpoint: btcwire.OutPoint{
+						Hash: btcwire.ShaHash([32]byte{
+							0x2a, 0xc7, 0xee, 0xf8,
+							0xa9, 0x62, 0x2d, 0xda,
+							0xec, 0x18, 0x3b, 0xba,
+							0xa9, 0x92, 0xb0, 0x7a,
+							0x70, 0x3b, 0x48, 0x86,
+							0x27, 0x9c, 0x46, 0xac,
+							0x25, 0xeb, 0x91, 0xec,
+							0x4c, 0x86, 0xd2, 0x9c,
+						}),
+						Index: 1,
+					},
+					SignatureScript: []byte{
+						btcscript.OP_DATA_71,
+						0x30, 0x44, 0x02, 0x20, 0xc3,
+						0x02, 0x3b, 0xed, 0x85, 0x0d,
+						0x94, 0x27, 0x8e, 0x06, 0xd2,
+						0x37, 0x92, 0x21, 0x55, 0x28,
+						0xdd, 0xdb, 0x63, 0xa4, 0xb6,
+						0x88, 0x33, 0x92, 0x06, 0xdd,
+						0xf9, 0xee, 0x72, 0x97, 0xa3,
+						0x08, 0x02, 0x20, 0x25, 0x00,
+						0x42, 0x8b, 0x26, 0x36, 0x45,
+						0x54, 0xcb, 0x11, 0xd3, 0x3e,
+						0x85, 0x35, 0x23, 0x49, 0x65,
+						0x82, 0x8e, 0x33, 0x6e, 0x1a,
+						0x4a, 0x72, 0x73, 0xeb, 0x5b,
+						0x8d, 0x1d, 0xd7, 0x02, 0xcc,
+						0x01,
+						btcscript.OP_DATA_65,
+						0x04, 0x49, 0x5c, 0x8f, 0x66,
+						0x90, 0x0d, 0xb7, 0x62, 0x69,
+						0x0b, 0x54, 0x49, 0xa1, 0xf4,
+						0xe7, 0xc2, 0xed, 0x1f, 0x4b,
+						0x34, 0x70, 0xfd, 0x42, 0x79,
+						0x68, 0xa1, 0x31, 0x76, 0x0c,
+						0x25, 0xf9, 0x12, 0x63, 0xad,
+						0x51, 0x73, 0x8e, 0x19, 0xb6,
+						0x07, 0xf5, 0xcf, 0x5f, 0x94,
+						0x27, 0x4a, 0x8b, 0xbc, 0x74,
+						0xba, 0x4b, 0x56, 0x0c, 0xe0,
+						0xb3, 0x08, 0x8f, 0x7f, 0x5c,
+						0x5f, 0xcf, 0xd6, 0xa0, 0x4b,
+					},
+					Sequence: 4294967295,
+				},
+			},
+			TxOut: []*btcwire.TxOut{
+				&btcwire.TxOut{
+					Value: 630320000,
+					PkScript: []byte{
+						btcscript.OP_DUP,
+						btcscript.OP_HASH160,
+						btcscript.OP_DATA_20,
+						0x43, 0xdc, 0x32, 0x1b, 0x66,
+						0x00, 0x51, 0x1f, 0xe0, 0xa9,
+						0x6a, 0x97, 0xc2, 0x59, 0x3a,
+						0x90, 0x54, 0x29, 0x74, 0xd6,
+						btcscript.OP_EQUALVERIFY,
+						btcscript.OP_CHECKSIG,
+					},
+				},
+				&btcwire.TxOut{
+					Value: 100000181,
+					PkScript: []byte{
+						btcscript.OP_DUP,
+						btcscript.OP_HASH160,
+						btcscript.OP_DATA_20,
+						0xa4, 0x05, 0xea, 0x18, 0x09,
+						0x14, 0xa9, 0x11, 0xd0, 0xb8,
+						0x07, 0x99, 0x19, 0x2b, 0x0b,
+						0x84, 0xae, 0x80, 0x1e, 0xbd,
+						btcscript.OP_EQUALVERIFY,
+						btcscript.OP_CHECKSIG,
+					},
+				},
+				&btcwire.TxOut{
+					Value: 596516343,
+					PkScript: []byte{
+						btcscript.OP_DUP,
+						btcscript.OP_HASH160,
+						btcscript.OP_DATA_20,
+						0x24, 0x56, 0x76, 0x45, 0x4f,
+						0x6f, 0xff, 0x28, 0x88, 0x39,
+						0x47, 0xea, 0x70, 0x23, 0x86,
+						0x9b, 0x8a, 0x71, 0xa3, 0x05,
+						btcscript.OP_EQUALVERIFY,
+						btcscript.OP_CHECKSIG,
+					},
+				},
+			},
+			LockTime: 0,
+		},
+		// Test input 0
+		pkScript: []byte{
+			btcscript.OP_DUP,
+			btcscript.OP_HASH160,
+			btcscript.OP_DATA_20,
+			0xfd, 0xf6, 0xea, 0xe7, 0x10,
+			0xa0, 0xc4, 0x49, 0x7a, 0x8d,
+			0x0f, 0xd2, 0x9a, 0xf6, 0x6b,
+			0xac, 0x94, 0xaf, 0x6c, 0x98,
+			btcscript.OP_EQUALVERIFY,
+			btcscript.OP_CHECKSIG,
+		},
+		idx:           0,
+		canonicalSigs: true,
+		shouldFail:    true,
+		nSigOps:       1,
+		scriptInfo: btcscript.ScriptInfo{
+			PkScriptClass:  btcscript.PubKeyHashTy,
+			NumInputs:      2,
+			ExpectedInputs: 2,
+			SigOps:         1,
+		},
+	},
+
 	// tx 51bf528ecf3c161e7c021224197dbe84f9a8564212f6207baa014c01a1668e1e
 	// first instance of an AnyoneCanPay signature in the blockchain
 	txTest{
@@ -1265,9 +1438,16 @@ var txTests = []txTest{
 // nothing in the blockchain that we have yet seen uses them, making it hard
 // to confirm we implemented the spec correctly.
 func testTx(t *testing.T, test txTest) {
+	var flags btcscript.ScriptFlags
+	if test.bip16 {
+		flags |= btcscript.ScriptBip16
+	}
+	if test.canonicalSigs {
+		flags |= btcscript.ScriptCanonicalSignatures
+	}
 	engine, err := btcscript.NewScript(
 		test.tx.TxIn[test.idx].SignatureScript, test.pkScript,
-		test.idx, test.tx, test.bip16)
+		test.idx, test.tx, flags)
 	if err != nil {
 		if err != test.parseErr {
 			t.Errorf("Failed to parse %s: got \"%v\" expected "+
@@ -1983,7 +2163,7 @@ func TestBadPC(t *testing.T) {
 
 	for _, test := range pcTests {
 		engine, err := btcscript.NewScript(tx.TxIn[0].SignatureScript,
-			pkScript, 0, tx, false)
+			pkScript, 0, tx, 0)
 		if err != nil {
 			t.Errorf("Failed to create script: %v", err)
 		}
@@ -2053,7 +2233,7 @@ func TestCheckErrorCondition(t *testing.T) {
 	}
 
 	engine, err := btcscript.NewScript(tx.TxIn[0].SignatureScript, pkScript,
-		0, tx, false)
+		0, tx, 0)
 	if err != nil {
 		t.Errorf("failed to create script: %v", err)
 	}
@@ -2460,10 +2640,11 @@ nexttest:
 		}
 
 		// Validate tx input scripts
+		scriptFlags := btcscript.ScriptBip16 | btcscript.ScriptCanonicalSignatures
 		for j, txin := range tx.TxIn {
 			engine, err := btcscript.NewScript(txin.SignatureScript,
 				SigScriptTests[i].inputs[j].txout.PkScript,
-				j, tx, true)
+				j, tx, scriptFlags)
 			if err != nil {
 				t.Errorf("cannot create script vm for test %v: %v",
 					SigScriptTests[i].name, err)

test_coverage.txt

@@ -4,17 +4,17 @@ github.com/conformal/btcscript/script.go	 Script.Step			 100.00% (37/37)
 github.com/conformal/btcscript/script.go	 parseScriptTemplate		 100.00% (30/30)
 github.com/conformal/btcscript/script.go	 CalcScriptInfo			 100.00% (25/25)
 github.com/conformal/btcscript/opcode.go	 parsedOpcode.bytes		 100.00% (23/23)
+github.com/conformal/btcscript/script.go	 sigDER				 100.00% (22/22)
+github.com/conformal/btcscript/script.go	 NewScript			 100.00% (21/21)
 github.com/conformal/btcscript/stack.go		 asInt				 100.00% (21/21)
-github.com/conformal/btcscript/script.go	 NewScript			 100.00% (18/18)
 github.com/conformal/btcscript/script.go	 signatureScriptCustomReader	 100.00% (15/15)
 github.com/conformal/btcscript/stack.go		 fromInt			 100.00% (14/14)
 github.com/conformal/btcscript/stack.go		 Stack.nipN			 100.00% (14/14)
+github.com/conformal/btcscript/script.go	 GetPreciseSigOpCount		 100.00% (13/13)
 github.com/conformal/btcscript/opcode.go	 opcodeWithin			 100.00% (13/13)
 github.com/conformal/btcscript/script.go	 isMultiSig			 100.00% (13/13)
-github.com/conformal/btcscript/script.go	 GetPreciseSigOpCount		 100.00% (13/13)
 github.com/conformal/btcscript/opcode.go	 parsedOpcode.print		 100.00% (12/12)
 github.com/conformal/btcscript/opcode.go	 opcodeNotIf			 100.00% (11/11)
-github.com/conformal/btcscript/script.go	 sigDER				 100.00% (11/11)
 github.com/conformal/btcscript/opcode.go	 opcodeIf			 100.00% (11/11)
 github.com/conformal/btcscript/opcode.go	 opcodeMax			 100.00% (10/10)
 github.com/conformal/btcscript/script.go	 getSigOpCount			 100.00% (10/10)
@@ -140,8 +140,8 @@ github.com/conformal/btcscript/script.go	 Script.SetStack		 100.00% (1/1)
 github.com/conformal/btcscript/stack.go		 Stack.PushByteArray		 100.00% (1/1)
 github.com/conformal/btcscript/stack.go		 Stack.PushInt			 100.00% (1/1)
 github.com/conformal/btcscript/opcode.go	 opcodeRot			 100.00% (1/1)
-github.com/conformal/btcscript/opcode.go	 opcodeCheckMultiSig		 98.21% (55/56)
+github.com/conformal/btcscript/opcode.go	 opcodeCheckMultiSig		 98.28% (57/58)
-github.com/conformal/btcscript/opcode.go	 opcodeCheckSig			 96.15% (25/26)
+github.com/conformal/btcscript/opcode.go	 opcodeCheckSig			 96.55% (28/29)
 github.com/conformal/btcscript/script.go	 calcScriptHash			 82.05% (32/39)
 github.com/conformal/btcscript/script.go	 Script.CheckErrorCondition	 78.57% (11/14)
 github.com/conformal/btcscript/opcode.go	 opcodeCheckSigVerify		 75.00% (3/4)
@@ -149,5 +149,5 @@ github.com/conformal/btcscript/script.go	 Script.Execute			 44.44% (8/18)
 github.com/conformal/btcscript/log.go		 SetLogWriter			 0.00% (0/7)
 github.com/conformal/btcscript/script.go	 IsPushOnlyScript		 0.00% (0/4)
 github.com/conformal/btcscript/log.go		 logClosure.String		 0.00% (0/1)
-github.com/conformal/btcscript			 ---------------------------	 96.52% (970/1005)
+github.com/conformal/btcscript			 ---------------------------	 96.58% (989/1024)