Merge pull request #2178 from ProofOfKeags/standardness-cleanup

Update standardness rules congruent to Bitcoin Core

mempool/mempool.go

@@ -49,6 +49,10 @@ const (
 	// can be evicted from the mempool when accepting a transaction
 	// replacement.
 	MaxReplacementEvictions = 100
+
+	// Transactions smaller than 65 non-witness bytes are not relayed to
+	// mitigate CVE-2017-12842.
+	MinStandardTxNonWitnessSize = 65
 )
 
 // Tag represents an identifier to use for tagging orphan transactions.  The
@@ -1355,6 +1359,12 @@ func (mp *TxPool) checkMempoolAcceptance(tx *btcutil.Tx,
 		return nil, txRuleError(wire.RejectDuplicate, str)
 	}
 
+	// Disallow transactions under the minimum standardness size.
+	if tx.MsgTx().SerializeSizeStripped() < MinStandardTxNonWitnessSize {
+		str := fmt.Sprintf("tx %v is too small", txHash)
+		return nil, txRuleError(wire.RejectNonstandard, str)
+	}
+
 	// Perform preliminary sanity checks on the transaction. This makes use
 	// of blockchain which contains the invariant rules for what
 	// transactions are allowed into blocks.

txscript/data/tx_invalid.json

@@ -333,6 +333,32 @@
 ["BIP143: wrong sighash (with FindAndDelete) = 17c50ec2181ecdfdc85ca081174b248199ba81fff730794d4f69b8ec031f2dce"],
 [[["9628667ad48219a169b41b020800162287d2c0f713c04157e95c484a8dcb7592", 7500, "0x00 0x20 0x9b66c15b4e0b4eb49fa877982cafded24859fe5b0e2dbfbe4f0df1de7743fd52", 200000]],
 "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", "P2SH,WITNESS"],
+[[["bc7fd132fcf817918334822ee6d9bd95c889099c96e07ca2c1eb2cc70db63224", 0, "CODESEPARATOR 0x21 0x038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041 CHECKSIG"]],
+"01000000012432b60dc72cebc1a27ce0969c0989c895bdd9e62e8234839117f8fc32d17fbc000000004a493046022100a576b52051962c25e642c0fd3d77ee6c92487048e5d90818bcf5b51abaccd7900221008204f8fb121be4ec3b24483b1f92d89b1b0548513a134e345c5442e86e8617a501ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["83e194f90b6ef21fa2e3a365b63794fb5daa844bdc9b25de30899fcfe7b01047", 0, "CODESEPARATOR CODESEPARATOR 0x21 0x038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041 CHECKSIG"]],
+"01000000014710b0e7cf9f8930de259bdc4b84aa5dfb9437b665a3e3a21ff26e0bf994e183000000004a493046022100a166121a61b4eeb19d8f922b978ff6ab58ead8a5a5552bf9be73dc9c156873ea02210092ad9bc43ee647da4f6652c320800debcf08ec20a094a0aaf085f63ecb37a17201ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["326882a7f22b5191f1a0cc9962ca4b878cd969cf3b3a70887aece4d801a0ba5e", 0, "0x21 0x038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041 CODESEPARATOR CHECKSIG"]],
+"01000000015ebaa001d8e4ec7a88703a3bcf69d98c874bca6299cca0f191512bf2a7826832000000004948304502203bf754d1c6732fbf87c5dcd81258aefd30f2060d7bd8ac4a5696f7927091dad1022100f5bcb726c4cf5ed0ed34cc13dadeedf628ae1045b7cb34421bc60b89f4cecae701ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["a955032f4d6b0c9bfe8cad8f00a8933790b9c1dc28c82e0f48e75b35da0e4944", 0, "0x21 0x038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041 CHECKSIGVERIFY CODESEPARATOR 0x21 0x038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041 CHECKSIGVERIFY CODESEPARATOR 1"]],
+"010000000144490eda355be7480f2ec828dcc1b9903793a8008fad8cfe9b0c6b4d2f0355a900000000924830450221009c0a27f886a1d8cb87f6f595fbc3163d28f7a81ec3c4b252ee7f3ac77fd13ffa02203caa8dfa09713c8c4d7ef575c75ed97812072405d932bd11e6a1593a98b679370148304502201e3861ef39a526406bad1e20ecad06be7375ad40ddb582c9be42d26c3a0d7b240221009d0a3985e96522e59635d19cc4448547477396ce0ef17a58e7d74c3ef464292301ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["a955032f4d6b0c9bfe8cad8f00a8933790b9c1dc28c82e0f48e75b35da0e4944", 0, "IF CODESEPARATOR ENDIF 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 CHECKSIGVERIFY CODESEPARATOR 1"]],
+"010000000144490eda355be7480f2ec828dcc1b9903793a8008fad8cfe9b0c6b4d2f0355a9000000004a48304502207a6974a77c591fa13dff60cabbb85a0de9e025c09c65a4b2285e47ce8e22f761022100f0efaac9ff8ac36b10721e0aae1fb975c90500b50c56e8a0cc52b0403f0425dd0100ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["a955032f4d6b0c9bfe8cad8f00a8933790b9c1dc28c82e0f48e75b35da0e4944", 0, "IF CODESEPARATOR ENDIF 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 CHECKSIGVERIFY CODESEPARATOR 1"]],
+"010000000144490eda355be7480f2ec828dcc1b9903793a8008fad8cfe9b0c6b4d2f0355a9000000004a483045022100fa4a74ba9fd59c59f46c3960cf90cbe0d2b743c471d24a3d5d6db6002af5eebb02204d70ec490fd0f7055a7c45f86514336e3a7f03503dacecabb247fc23f15c83510151ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["ccf7f4053a02e653c36ac75c891b7496d0dc5ce5214f6c913d9cf8f1329ebee0", 0, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+"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", "P2SH,CONST_SCRIPTCODE"],
+[[["10c9f0effe83e97f80f067de2b11c6a00c3088a4bce42c5ae761519af9306f3c", 1, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+"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", "P2SH,CONST_SCRIPTCODE"],
+[[["6056ebd549003b10cbbd915cea0d82209fe40b8617104be917a26fa92cbe3d6f", 0, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+"01000000016f3dbe2ca96fa217e94b1017860be49f20820dea5c91bdcb103b0049d5eb566000000000fd1d0147304402203989ac8f9ad36b5d0919d97fa0a7f70c5272abee3b14477dc646288a8b976df5022027d19da84a066af9053ad3d1d7459d171b7e3a80bc6c4ef7a330677a6be548140147304402203989ac8f9ad36b5d0919d97fa0a7f70c5272abee3b14477dc646288a8b976df5022027d19da84a066af9053ad3d1d7459d171b7e3a80bc6c4ef7a330677a6be548140121038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041ac47304402203757e937ba807e4a5da8534c17f9d121176056406a6465054bdd260457515c1a02200f02eccf1bec0f3a0d65df37889143c2e88ab7acec61a7b6f5aa264139141a2b0121038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+[[["5a6b0021a6042a686b6b94abc36b387bef9109847774e8b1e51eb8cc55c53921", 1, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+"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", "P2SH,CONST_SCRIPTCODE"],
+[[["b5b598de91787439afd5938116654e0b16b7a0d0f82742ba37564219c5afcbf9", 0, "DUP HASH160 0x14 0xf6f365c40f0739b61de827a44751e5e99032ed8f EQUALVERIFY CHECKSIG"],
+["ab9805c6d57d7070d9a42c5176e47bb705023e6b67249fb6760880548298e742", 0, "HASH160 0x14 0xd8dacdadb7462ae15cd906f1878706d0da8660e6 EQUAL"]],
+"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", "P2SH,CONST_SCRIPTCODE"],
+[[["ceafe58e0f6e7d67c0409fbbf673c84c166e3c5d3c24af58f7175b18df3bb3db", 0, "DUP HASH160 0x14 0xf6f365c40f0739b61de827a44751e5e99032ed8f EQUALVERIFY CHECKSIG"],
+["ceafe58e0f6e7d67c0409fbbf673c84c166e3c5d3c24af58f7175b18df3bb3db", 1, "2 0x48 0x3045022015bd0139bcccf990a6af6ec5c1c52ed8222e03a0d51c334df139968525d2fcd20221009f9efe325476eb64c3958e4713e9eefe49bf1d820ed58d2112721b134e2a1a5303 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 3 CHECKMULTISIG"]],
+"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", "P2SH,CONST_SCRIPTCODE"],
 
 ["Make diffs cleaner by leaving a comment here without comma at the end"]
 ]

txscript/data/tx_valid.json

@@ -471,17 +471,17 @@
 ["BIP143 example: P2WSH with OP_CODESEPARATOR and out-of-range SIGHASH_SINGLE."],
 [[["6eb316926b1c5d567cd6f5e6a84fec606fc53d7b474526d1fff3948020c93dfe", 0, "0x21 0x036d5c20fa14fb2f635474c1dc4ef5909d4568e5569b79fc94d3448486e14685f8 CHECKSIG", 156250000],
 ["f825690aee1b3dc247da796cacb12687a5e802429fd291cfd63e010f02cf1508", 0, "0x00 0x20 0x5d1b56b63d714eebe542309525f484b7e9d6f686b3781b6f61ef925d66d6f6a0", 4900000000]],
-"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", "P2SH,WITNESS"],
+"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", "P2SH,WITNESS,CONST_SCRIPTCODE"],
 
 ["BIP143 example: P2WSH with unexecuted OP_CODESEPARATOR and SINGLE|ANYONECANPAY"],
 [[["01c0cf7fba650638e55eb91261b183251fbb466f90dff17f10086817c542b5e9", 0, "0x00 0x20 0xba468eea561b26301e4cf69fa34bde4ad60c81e70f059f045ca9a79931004a4d", 16777215],
 ["1b2a9a426ba603ba357ce7773cb5805cb9c7c2b386d100d1fc9263513188e680", 0, "0x00 0x20 0xd9bbfbe56af7c4b7f960a70d7ea107156913d9e5a26b0a71429df5e097ca6537", 16777215]],
-"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", "P2SH,WITNESS"],
+"01000000000102e9b542c5176808107ff1df906f46bb1f2583b16112b95ee5380665ba7fcfc0010000000000ffffffff80e68831516392fcd100d186b3c2c7b95c80b53c77e77c35ba03a66b429a2a1b0000000000ffffffff0280969800000000001976a914de4b231626ef508c9a74a8517e6783c0546d6b2888ac80969800000000001976a9146648a8cd4531e1ec47f35916de8e259237294d1e88ac02483045022100f6a10b8604e6dc910194b79ccfc93e1bc0ec7c03453caaa8987f7d6c3413566002206216229ede9b4d6ec2d325be245c5b508ff0339bf1794078e20bfe0babc7ffe683270063ab68210392972e2eb617b2388771abe27235fd5ac44af8e61693261550447a4c3e39da98ac024730440220032521802a76ad7bf74d0e2c218b72cf0cbc867066e2e53db905ba37f130397e02207709e2188ed7f08f4c952d9d13986da504502b8c3be59617e043552f506c46ff83275163ab68210392972e2eb617b2388771abe27235fd5ac44af8e61693261550447a4c3e39da98ac00000000", "P2SH,WITNESS,CONST_SCRIPTCODE"],
 
 ["BIP143 example: Same as the previous example with input-output pairs swapped"],
 [[["1b2a9a426ba603ba357ce7773cb5805cb9c7c2b386d100d1fc9263513188e680", 0, "0x00 0x20 0xd9bbfbe56af7c4b7f960a70d7ea107156913d9e5a26b0a71429df5e097ca6537", 16777215],
 ["01c0cf7fba650638e55eb91261b183251fbb466f90dff17f10086817c542b5e9", 0, "0x00 0x20 0xba468eea561b26301e4cf69fa34bde4ad60c81e70f059f045ca9a79931004a4d", 16777215]],
-"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", "P2SH,WITNESS"],
+"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", "P2SH,WITNESS,CONST_SCRIPTCODE"],
 
 ["BIP143 example: P2SH-P2WSH 6-of-6 multisig signed with 6 different SIGHASH types"],
 [[["6eb98797a21c6c10aa74edf29d618be109f48a8e94c694f3701e08ca69186436", 1, "HASH160 0x14 0x9993a429037b5d912407a71c252019287b8d27a5 EQUAL", 987654321]],
@@ -498,7 +498,7 @@
 "010000000169c12106097dc2e0526493ef67f21269fe888ef05c7a3a5dacab38e1ac8387f1581b0000b64830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e0121037a3fb04bcdb09eba90f69961ba1692a3528e45e67c85b200df820212d7594d334aad4830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e01ffffffff0101000000000000000000000000", "P2SH,WITNESS"],
 ["BIP143: correct sighash (without FindAndDelete) = 71c9cd9b2869b9c70b01b1f0360c148f42dee72297db312638df136f43311f23"],
 [[["f18783ace138abac5d3a7a5cf08e88fe6912f267ef936452e0c27d090621c169", 7500, "0x00 0x20 0x9e1be07558ea5cc8e02ed1d80c0911048afad949affa36d5c3951e3159dbea19", 200000]],
-"0100000000010169c12106097dc2e0526493ef67f21269fe888ef05c7a3a5dacab38e1ac8387f14c1d000000ffffffff01010000000000000000034830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e012102a9781d66b61fb5a7ef00ac5ad5bc6ffc78be7b44a566e3c87870e1079368df4c4aad4830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e0100000000", "P2SH,WITNESS"],
+"0100000000010169c12106097dc2e0526493ef67f21269fe888ef05c7a3a5dacab38e1ac8387f14c1d000000ffffffff01010000000000000000034830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e012102a9781d66b61fb5a7ef00ac5ad5bc6ffc78be7b44a566e3c87870e1079368df4c4aad4830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e0100000000", "P2SH,WITNESS,CONST_SCRIPTCODE"],
 ["This is multisig version of the FindAndDelete tests"],
 ["Script is 2 CHECKMULTISIGVERIFY <sig1> <sig2> DROP"],
 ["52af4830450220487fb382c4974de3f7d834c1b617fe15860828c7f96454490edd6d891556dcc9022100baf95feb48f845d5bfc9882eb6aeefa1bc3790e39f59eaa46ff7f15ae626c53e0148304502205286f726690b2e9b0207f0345711e63fa7012045b9eb0f19c2458ce1db90cf43022100e89f17f86abc5b149eba4115d4f128bcf45d77fb3ecdd34f594091340c0395960175"],
@@ -508,7 +508,9 @@
 "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", "P2SH,WITNESS"],
 ["BIP143: correct sighash (without FindAndDelete) = c1628a1e7c67f14ca0c27c06e4fdeec2e6d1a73c7a91d7c046ff83e835aebb72"],
 [[["9628667ad48219a169b41b020800162287d2c0f713c04157e95c484a8dcb7592", 7500, "0x00 0x20 0x9b66c15b4e0b4eb49fa877982cafded24859fe5b0e2dbfbe4f0df1de7743fd52", 200000]],
-"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", "P2SH,WITNESS"],
+"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", "P2SH,WITNESS,CONST_SCRIPTCODE"],
+[[["7a554c397846f025738965683b8448d79458c54b869f6391ece95145c962e65f", 0, "OP_HASH160 0x149512447916448e4193c321f2d599dff2538973f3 OP_EQUAL", 0]],
+"02000000015fe662c94551e9ec91639f864bc55894d748843b6865897325f04678394c557a0000000039093006020101020101012103f0665be3ccc59a592608790e84bcf117349fc76c77d06cd3fb323548c310ff340cad0a09300602010102010101ffffffff010000000000000000015100000000", "CHECKLOCKTIMEVERIFY,CHECKSEQUENCEVERIFY,CLEANSTACK,DERSIG,DISCOURAGE_UPGRADABLE_NOPS,LOW_S,MINIMALDATA,NULLDUMMY,NULLFAIL,P2SH,SIGPUSHONLY,STRICTENC,WITNESS,DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM,MINIMALIF,WITNESS_PUBKEYTYPE,TAPROOT"],
 
 ["Make diffs cleaner by leaving a comment here without comma at the end"]
 ]

txscript/engine.go

@@ -114,6 +114,10 @@ const (
 	// ScriptVerifyDiscourageUpgradeablePubkeyType defines if unknown
 	// public key versions (during tapscript execution) is non-standard.
 	ScriptVerifyDiscourageUpgradeablePubkeyType
+
+	// ScriptVerifyConstScriptCode fails non-segwit scripts if a signature
+	// match is found in the script code or if OP_CODESEPARATOR is used.
+	ScriptVerifyConstScriptCode
 )
 
 const (

txscript/error.go

@@ -408,6 +408,14 @@ const (
 	// is exceeded during taproot execution.
 	ErrTaprootMaxSigOps
 
+	// ErrNonConstScriptCode is returned when a signature match is found when
+	// calling removeOpcodeByData in a non-segwit script.
+	ErrNonConstScriptCode
+
+	// ErrCodeSeparator is returned when OP_CODESEPARATOR is used in a
+	// non-segwit script.
+	ErrCodeSeparator
+
 	// numErrorCodes is the maximum error code number used in tests.  This
 	// entry MUST be the last entry in the enum.
 	numErrorCodes
@@ -494,6 +502,8 @@ var errorCodeStrings = map[ErrorCode]string{
 	ErrInvalidTaprootSigLen:                "ErrInvalidTaprootSigLen",
 	ErrTaprootPubkeyIsEmpty:                "ErrTaprootPubkeyIsEmpty",
 	ErrTaprootMaxSigOps:                    "ErrTaprootMaxSigOps",
+	ErrNonConstScriptCode:                  "ErrNonConstScriptCode",
+	ErrCodeSeparator:                       "ErrCodeSeparator",
 }
 
 // String returns the ErrorCode as a human-readable name.

txscript/error_test.go

@@ -96,6 +96,8 @@ func TestErrorCodeStringer(t *testing.T) {
 		{ErrInvalidTaprootSigLen, "ErrInvalidTaprootSigLen"},
 		{ErrTaprootPubkeyIsEmpty, "ErrTaprootPubkeyIsEmpty"},
 		{ErrTaprootMaxSigOps, "ErrTaprootMaxSigOps"},
+		{ErrNonConstScriptCode, "ErrNonConstScriptCode"},
+		{ErrCodeSeparator, "ErrCodeSeparator"},
 		{0xffff, "Unknown ErrorCode (65535)"},
 	}
 

txscript/opcode.go

@@ -1953,6 +1953,12 @@ func opcodeCodeSeparator(op *opcode, data []byte, vm *Engine) error {
 
 	if vm.taprootCtx != nil {
 		vm.taprootCtx.codeSepPos = uint32(vm.tokenizer.OpcodePosition())
+	} else if vm.witnessProgram == nil &&
+		vm.hasFlag(ScriptVerifyConstScriptCode) {
+
+		// Disable OP_CODESEPARATOR for non-segwit scripts.
+		str := "OP_CODESEPARATOR used in non-segwit script"
+		return scriptError(ErrCodeSeparator, str)
 	}
 
 	return nil
@@ -2073,7 +2079,13 @@ func opcodeCheckSig(op *opcode, data []byte, vm *Engine) error {
 		// TODO(roasbeef): return an error?
 	}
 
-	valid := sigVerifier.Verify()
+	result := sigVerifier.Verify()
+	valid := result.sigValid
+
+	if vm.hasFlag(ScriptVerifyConstScriptCode) && result.sigMatch {
+		str := "non-const script code"
+		return scriptError(ErrNonConstScriptCode, str)
+	}
 
 	switch {
 	// For tapscript, and prior execution with null fail active, if the
@@ -2166,11 +2178,11 @@ func opcodeCheckSigAdd(op *opcode, data []byte, vm *Engine) error {
 		return err
 	}
 
-	valid := sigVerifier.Verify()
+	result := sigVerifier.Verify()
 
 	// If the signature is invalid, this we fail execution, as it should
 	// have been an empty signature.
-	if !valid {
+	if !result.sigValid {
 		str := "signature not empty on failed checksig"
 		return scriptError(ErrNullFail, str)
 	}
@@ -2303,7 +2315,13 @@ func opcodeCheckMultiSig(op *opcode, data []byte, vm *Engine) error {
 	// no way for a signature to sign itself.
 	if !vm.isWitnessVersionActive(0) {
 		for _, sigInfo := range signatures {
-			script = removeOpcodeByData(script, sigInfo.signature)
+			var match bool
+			script, match = removeOpcodeByData(script, sigInfo.signature)
+			if vm.hasFlag(ScriptVerifyConstScriptCode) && match {
+				str := fmt.Sprintf("got match of %v in %v", sigInfo.signature,
+					script)
+				return scriptError(ErrNonConstScriptCode, str)
+			}
 		}
 	}
 

txscript/reference_test.go

@@ -196,6 +196,8 @@ func parseScriptFlags(flagStr string) (ScriptFlags, error) {
 			flags |= ScriptVerifyWitnessPubKeyType
 		case "TAPROOT":
 			flags |= ScriptVerifyTaproot
+		case "CONST_SCRIPTCODE":
+			flags |= ScriptVerifyConstScriptCode
 		default:
 			return flags, fmt.Errorf("invalid flag: %s", flag)
 		}

txscript/script.go

@@ -255,10 +255,10 @@ func isCanonicalPush(opcode byte, data []byte) bool {
 // NOTE: This function is only valid for version 0 scripts.  Since the function
 // does not accept a script version, the results are undefined for other script
 // versions.
-func removeOpcodeByData(script []byte, dataToRemove []byte) []byte {
+func removeOpcodeByData(script []byte, dataToRemove []byte) ([]byte, bool) {
 	// Avoid work when possible.
 	if len(script) == 0 || len(dataToRemove) == 0 {
-		return script
+		return script, false
 	}
 
 	// Parse through the script looking for a canonical data push that contains
@@ -266,8 +266,28 @@ func removeOpcodeByData(script []byte, dataToRemove []byte) []byte {
 	const scriptVersion = 0
 	var result []byte
 	var prevOffset int32
+	var match bool
 	tokenizer := MakeScriptTokenizer(scriptVersion, script)
 	for tokenizer.Next() {
+		var found bool
+		result, prevOffset, found = removeOpcodeCanonical(
+			&tokenizer, script, dataToRemove, prevOffset, result,
+		)
+		if found {
+			match = true
+		}
+	}
+	if result == nil {
+		result = script
+	}
+	return result, match
+}
+
+func removeOpcodeCanonical(t *ScriptTokenizer, script, dataToRemove []byte,
+	prevOffset int32, result []byte) ([]byte, int32, bool) {
+
+	var found bool
+
 	// In practice, the script will basically never actually contain the
 	// data since this function is only used during signature verification
 	// to remove the signature itself which would require some incredibly
@@ -275,23 +295,19 @@ func removeOpcodeByData(script []byte, dataToRemove []byte) []byte {
 	//
 	// Thus, as an optimization, avoid allocating a new script unless there
 	// is actually a match that needs to be removed.
-		op, data := tokenizer.Opcode(), tokenizer.Data()
+	op, data := t.Opcode(), t.Data()
-		if isCanonicalPush(op, data) && bytes.Contains(data, dataToRemove) {
+	if isCanonicalPush(op, data) && bytes.Equal(data, dataToRemove) {
 		if result == nil {
-				fullPushLen := tokenizer.ByteIndex() - prevOffset
+			fullPushLen := t.ByteIndex() - prevOffset
 			result = make([]byte, 0, int32(len(script))-fullPushLen)
 			result = append(result, script[0:prevOffset]...)
 		}
+		found = true
 	} else if result != nil {
-			result = append(result, script[prevOffset:tokenizer.ByteIndex()]...)
+		result = append(result, script[prevOffset:t.ByteIndex()]...)
 	}
 
-		prevOffset = tokenizer.ByteIndex()
+	return result, t.ByteIndex(), found
-	}
-	if result == nil {
-		result = script
-	}
-	return result
 }
 
 // AsSmallInt returns the passed opcode, which must be true according to

txscript/script_test.go

@@ -357,6 +357,12 @@ func TestRemoveOpcodeByData(t *testing.T) {
 			remove: []byte{1, 2, 3, 4},
 			after:  []byte{OP_NOP},
 		},
+		{
+			name:   "",
+			before: []byte{OP_NOP, OP_DATA_8, 1, 2, 3, 4, 5, 6, 7, 8, OP_DATA_4, 1, 2, 3, 4},
+			remove: []byte{1, 2, 3, 4},
+			after:  []byte{OP_NOP, OP_DATA_8, 1, 2, 3, 4, 5, 6, 7, 8},
+		},
 		{
 			name:   "simple case",
 			before: []byte{OP_DATA_4, 1, 2, 3, 4},
@@ -376,7 +382,9 @@ func TestRemoveOpcodeByData(t *testing.T) {
 				bytes.Repeat([]byte{0}, 72)...),
 				[]byte{1, 2, 3, 4}...),
 			remove: []byte{1, 2, 3, 4},
-			after:  nil,
+			after: append(append([]byte{OP_PUSHDATA1, 76},
+				bytes.Repeat([]byte{0}, 72)...),
+				[]byte{1, 2, 3, 4}...),
 		},
 		{
 			name: "simple case (pushdata1 miss)",
@@ -400,7 +408,9 @@ func TestRemoveOpcodeByData(t *testing.T) {
 				bytes.Repeat([]byte{0}, 252)...),
 				[]byte{1, 2, 3, 4}...),
 			remove: []byte{1, 2, 3, 4},
-			after:  nil,
+			after: append(append([]byte{OP_PUSHDATA2, 0, 1},
+				bytes.Repeat([]byte{0}, 252)...),
+				[]byte{1, 2, 3, 4}...),
 		},
 		{
 			name: "simple case (pushdata2 miss)",
@@ -425,7 +435,9 @@ func TestRemoveOpcodeByData(t *testing.T) {
 				bytes.Repeat([]byte{0}, 65532)...),
 				[]byte{1, 2, 3, 4}...),
 			remove: []byte{1, 2, 3, 4},
-			after:  nil,
+			after: append(append([]byte{OP_PUSHDATA4, 0, 0, 1, 0},
+				bytes.Repeat([]byte{0}, 65532)...),
+				[]byte{1, 2, 3, 4}...),
 		},
 		{
 			name:   "simple case (pushdata4 miss noncanonical)",
@@ -465,16 +477,17 @@ func TestRemoveOpcodeByData(t *testing.T) {
 	// tstRemoveOpcodeByData is a convenience function to ensure the provided
 	// script parses before attempting to remove the passed data.
 	const scriptVersion = 0
-	tstRemoveOpcodeByData := func(script []byte, data []byte) ([]byte, error) {
+	tstRemoveOpcodeByData := func(script []byte, data []byte) ([]byte, bool, error) {
 		if err := checkScriptParses(scriptVersion, script); err != nil {
-			return nil, err
+			return nil, false, err
 		}
 
-		return removeOpcodeByData(script, data), nil
+		result, match := removeOpcodeByData(script, data)
+		return result, match, nil
 	}
 
 	for _, test := range tests {
-		result, err := tstRemoveOpcodeByData(test.before, test.remove)
+		result, _, err := tstRemoveOpcodeByData(test.before, test.remove)
 		if e := tstCheckScriptError(err, test.err); e != nil {
 			t.Errorf("%s: %v", test.name, e)
 			continue

txscript/sigvalidate.go

@@ -20,9 +20,14 @@ import (
 // pre-segwit, segwit v0, segwit v1 (taproot key spend validation), and the
 // base tapscript verification.
 type signatureVerifier interface {
-	// Verify returns true if the signature verifier context deems the
+	// Verify returns whether or not the signature verifier context deems the
 	// signature to be valid for the given context.
-	Verify() bool
+	Verify() verifyResult
+}
+
+type verifyResult struct {
+	sigValid bool
+	sigMatch bool
 }
 
 // baseSigVerifier is used to verify signatures for the _base_ system, meaning
@@ -147,20 +152,23 @@ func (b *baseSigVerifier) verifySig(sigHash []byte) bool {
 	return valid
 }
 
-// Verify returns true if the signature verifier context deems the signature to
+// Verify returns whether or not the signature verifier context deems the
-// be valid for the given context.
+// signature to be valid for the given context.
 //
 // NOTE: This is part of the baseSigVerifier interface.
-func (b *baseSigVerifier) Verify() bool {
+func (b *baseSigVerifier) Verify() verifyResult {
 	// Remove the signature since there is no way for a signature
 	// to sign itself.
-	subScript := removeOpcodeByData(b.subScript, b.fullSigBytes)
+	subScript, match := removeOpcodeByData(b.subScript, b.fullSigBytes)
 
 	sigHash := calcSignatureHash(
 		subScript, b.hashType, &b.vm.tx, b.vm.txIdx,
 	)
 
-	return b.verifySig(sigHash)
+	return verifyResult{
+		sigValid: b.verifySig(sigHash),
+		sigMatch: match,
+	}
 }
 
 // A compile-time assertion to ensure baseSigVerifier implements the
@@ -192,7 +200,7 @@ func newBaseSegwitSigVerifier(pkBytes, fullSigBytes []byte,
 // be valid for the given context.
 //
 // NOTE: This is part of the baseSigVerifier interface.
-func (s *baseSegwitSigVerifier) Verify() bool {
+func (s *baseSegwitSigVerifier) Verify() verifyResult {
 	var sigHashes *TxSigHashes
 	if s.vm.hashCache != nil {
 		sigHashes = s.vm.hashCache
@@ -208,10 +216,12 @@ func (s *baseSegwitSigVerifier) Verify() bool {
 		// TODO(roasbeef): this doesn't need to return an error, should
 		// instead be further up the stack? this only returns an error
 		// if the input index is greater than the number of inputs
-		return false
+		return verifyResult{}
 	}
 
-	return s.verifySig(sigHash)
+	return verifyResult{
+		sigValid: s.verifySig(sigHash),
+	}
 }
 
 // A compile-time assertion to ensure baseSegwitSigVerifier implements the
@@ -356,11 +366,11 @@ func (t *taprootSigVerifier) verifySig(sigHash []byte) bool {
 	return false
 }
 
-// Verify returns true if the signature verifier context deems the signature to
+// Verify returns whether or not the signature verifier context deems the
-// be valid for the given context.
+// signature to be valid for the given context.
 //
 // NOTE: This is part of the baseSigVerifier interface.
-func (t *taprootSigVerifier) Verify() bool {
+func (t *taprootSigVerifier) Verify() verifyResult {
 	var opts []TaprootSigHashOption
 	if t.annex != nil {
 		opts = append(opts, WithAnnex(t.annex))
@@ -374,10 +384,12 @@ func (t *taprootSigVerifier) Verify() bool {
 	)
 	if err != nil {
 		// TODO(roasbeef): propagate the error here?
-		return false
+		return verifyResult{}
 	}
 
-	return t.verifySig(sigHash)
+	return verifyResult{
+		sigValid: t.verifySig(sigHash),
+	}
 }
 
 // A compile-time assertion to ensure taprootSigVerifier implements the
@@ -439,16 +451,18 @@ func newBaseTapscriptSigVerifier(pkBytes, rawSig []byte,
 	}
 }
 
-// Verify returns true if the signature verifier context deems the signature to
+// Verify returns whether or not the signature verifier context deems the
-// be valid for the given context.
+// signature to be valid for the given context.
 //
 // NOTE: This is part of the baseSigVerifier interface.
-func (b *baseTapscriptSigVerifier) Verify() bool {
+func (b *baseTapscriptSigVerifier) Verify() verifyResult {
 	// If the public key is blank, then that means it wasn't 0 or 32 bytes,
 	// so we'll treat this as an unknown public key version and return
-	// true.
+	// that it's valid.
 	if b.pubKey == nil {
-		return true
+		return verifyResult{
+			sigValid: true,
+		}
 	}
 
 	var opts []TaprootSigHashOption
@@ -468,10 +482,12 @@ func (b *baseTapscriptSigVerifier) Verify() bool {
 	)
 	if err != nil {
 		// TODO(roasbeef): propagate the error here?
-		return false
+		return verifyResult{}
 	}
 
-	return b.verifySig(sigHash)
+	return verifyResult{
+		sigValid: b.verifySig(sigHash),
+	}
 }
 
 // A compile-time assertion to ensure baseTapscriptSigVerifier implements the

txscript/standard.go

@@ -46,7 +46,8 @@ const (
 		ScriptVerifyTaproot |
 		ScriptVerifyDiscourageUpgradeableTaprootVersion |
 		ScriptVerifyDiscourageOpSuccess |
-		ScriptVerifyDiscourageUpgradeablePubkeyType
+		ScriptVerifyDiscourageUpgradeablePubkeyType |
+		ScriptVerifyConstScriptCode
 )
 
 // ScriptClass is an enumeration for the list of standard types of script.

txscript/taproot.go

@@ -84,8 +84,8 @@ func VerifyTaprootKeySpend(witnessProgram []byte, rawSig []byte, tx *wire.MsgTx,
 		return err
 	}
 
-	valid := keySpendVerifier.Verify()
+	result := keySpendVerifier.Verify()
-	if valid {
+	if result.sigValid {
 		return nil
 	}
 

wire/msgtx.go

@@ -112,6 +112,14 @@ const (
 	maxWitnessItemSize = 4_000_000
 )
 
+var (
+	// errSuperfluousWitnessRecord is returned during tx deserialization when
+	// a tx has the witness marker flag set but has no witnesses.
+	errSuperfluousWitnessRecord = fmt.Errorf(
+		"witness flag set but tx has no witnesses",
+	)
+)
+
 // TxFlagMarker is the first byte of the FLAG field in a bitcoin tx
 // message. It allows decoders to distinguish a regular serialized
 // transaction from one that would require a different parsing logic.
@@ -601,8 +609,7 @@ func (msg *MsgTx) btcDecode(r io.Reader, pver uint32, enc MessageEncoding,
 			txin.Witness = make([][]byte, witCount)
 			for j := uint64(0); j < witCount; j++ {
 				txin.Witness[j], err = readScriptBuf(
-					r, pver, buf, sbuf, maxWitnessItemSize,
+					r, pver, buf, sbuf, "script witness item",
-					"script witness item",
 				)
 				if err != nil {
 					return err
@@ -611,6 +618,12 @@ func (msg *MsgTx) btcDecode(r io.Reader, pver uint32, enc MessageEncoding,
 				sbuf = sbuf[len(txin.Witness[j]):]
 			}
 		}
+
+		// Check that if the witness flag is set that we actually have
+		// witnesses. This check is also done by bitcoind.
+		if !msg.HasWitness() {
+			return errSuperfluousWitnessRecord
+		}
 	}
 
 	if _, err := io.ReadFull(r, buf[:4]); err != nil {
@@ -1004,7 +1017,7 @@ func writeOutPointBuf(w io.Writer, pver uint32, version int32, op *OutPoint,
 //
 // NOTE: b MUST either be nil or at least an 8-byte slice.
 func readScriptBuf(r io.Reader, pver uint32, buf, s []byte,
-	maxAllowed uint32, fieldName string) ([]byte, error) {
+	fieldName string) ([]byte, error) {
 
 	count, err := ReadVarIntBuf(r, pver, buf)
 	if err != nil {
@@ -1014,9 +1027,9 @@ func readScriptBuf(r io.Reader, pver uint32, buf, s []byte,
 	// Prevent byte array larger than the max message size.  It would
 	// be possible to cause memory exhaustion and panics without a sane
 	// upper bound on this count.
-	if count > uint64(maxAllowed) {
+	if count > maxWitnessItemSize {
 		str := fmt.Sprintf("%s is larger than the max allowed size "+
-			"[count %d, max %d]", fieldName, count, maxAllowed)
+			"[count %d, max %d]", fieldName, count, maxWitnessItemSize)
 		return nil, messageError("readScript", str)
 	}
 
@@ -1043,8 +1056,9 @@ func readTxInBuf(r io.Reader, pver uint32, version int32, ti *TxIn,
 		return err
 	}
 
-	ti.SignatureScript, err = readScriptBuf(r, pver, buf, s, MaxMessagePayload,
+	ti.SignatureScript, err = readScriptBuf(
-		"transaction input signature script")
+		r, pver, buf, s, "transaction input signature script",
+	)
 	if err != nil {
 		return err
 	}
@@ -1107,8 +1121,7 @@ func readTxOutBuf(r io.Reader, pver uint32, version int32, to *TxOut,
 	to.Value = int64(littleEndian.Uint64(buf))
 
 	to.PkScript, err = readScriptBuf(
-		r, pver, buf, s, MaxMessagePayload,
+		r, pver, buf, s, "transaction output public key script",
-		"transaction output public key script",
 	)
 	return err
 }

wire/msgtx_test.go

@@ -6,6 +6,7 @@ package wire
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"reflect"
@@ -877,6 +878,17 @@ func TestTxOutPointFromString(t *testing.T) {
 	}
 }
 
+// TestTxSuperfluousWitnessRecord ensures that btcd fails to parse a tx with
+// the witness marker flag set but without any actual witnesses.
+func TestTxSuperfluousWitnessRecord(t *testing.T) {
+	m := &MsgTx{}
+	rbuf := bytes.NewReader(multiWitnessFlagNoWitness)
+	err := m.BtcDecode(rbuf, ProtocolVersion, WitnessEncoding)
+	if !errors.Is(err, errSuperfluousWitnessRecord) {
+		t.Fatalf("should have failed with %v", errSuperfluousWitnessRecord)
+	}
+}
+
 // multiTx is a MsgTx with an input and output and used in various tests.
 var multiTx = &MsgTx{
 	Version: 1,
@@ -1029,6 +1041,33 @@ var multiWitnessTx = &MsgTx{
 	},
 }
 
+// multiWitnessFlagNoWitness is the wire encoded bytes for multiWitnessTx with
+// the witness flag set but with witnesses omitted.
+var multiWitnessFlagNoWitness = []byte{
+	0x1, 0x0, 0x0, 0x0, // Version
+	TxFlagMarker, // Marker byte indicating 0 inputs, or a segwit encoded tx
+	WitnessFlag,  // Flag byte
+	0x1,          // Varint for number of inputs
+	0xa5, 0x33, 0x52, 0xd5, 0x13, 0x57, 0x66, 0xf0,
+	0x30, 0x76, 0x59, 0x74, 0x18, 0x26, 0x3d, 0xa2,
+	0xd9, 0xc9, 0x58, 0x31, 0x59, 0x68, 0xfe, 0xa8,
+	0x23, 0x52, 0x94, 0x67, 0x48, 0x1f, 0xf9, 0xcd, // Previous output hash
+	0x13, 0x0, 0x0, 0x0, // Little endian previous output index
+	0x0,                    // No sig script (this is a witness input)
+	0xff, 0xff, 0xff, 0xff, // Sequence
+	0x1,                                    // Varint for number of outputs
+	0xb, 0x7, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, // Output amount
+	0x16, // Varint for length of pk script
+	0x0,  // Version 0 witness program
+	0x14, // OP_DATA_20
+	0x9d, 0xda, 0xc6, 0xf3, 0x9d, 0x51, 0xe0, 0x39,
+	0x8e, 0x53, 0x2a, 0x22, 0xc4, 0x1b, 0xa1, 0x89,
+	0x40, 0x6a, 0x85, 0x23, // 20-byte pub key hash
+	0x00,               // No item on the witness stack for the first input
+	0x00,               // No item on the witness stack for the second input
+	0x0, 0x0, 0x0, 0x0, // Lock time
+}
+
 // multiWitnessTxEncoded is the wire encoded bytes for multiWitnessTx including inputs
 // with witness data using protocol version 70012 and is used in the various
 // tests.