Merge #11423: [Policy] Several transaction standardness rules

364bae5 qa: Pad scriptPubKeys to get minimum sized txs (MarcoFalke)
7485488 Policy to reject extremely small transactions (Johnson Lau)
0f8719b Add transaction tests for constant scriptCode (Johnson Lau)
9dabfe4 Add constant scriptCode policy in non-segwit scripts (Johnson Lau)

Pull request description:

  This disables `OP_CODESEPARATOR` in non-segwit scripts (even in an unexecuted branch), and makes a positive `FindAndDelete` result invalid. This ensures that the `scriptCode` serialized in `SignatureHash` is always the same as the script passing to the `EvalScript`.

Tree-SHA512: a0552cb920294d130251c48053fa2ff1fbdd26332e62b52147d918837852750f0ce35ce2cd1cbdb86588943312f8154ccb4925e850dbb7c2254bc353070cd5f8

10 files changed, 91 insertions, 8 deletions

diff --git a/src/policy/policy.h b/src/policy/policy.h
index e4eda4b635..5ce019df4c 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -22,6 +22,8 @@ static const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000;
 static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000;
 /** The maximum weight for transactions we're willing to relay/mine */
 static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000;
+/** The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) */
+static const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82;
 /** Maximum number of signature check operations in an IsStandard() P2SH script */
 static const unsigned int MAX_P2SH_SIGOPS = 15;
 /** The maximum number of sigops we're willing to relay/mine in a single tx */
@@ -63,7 +65,8 @@ static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VE
                                                              SCRIPT_VERIFY_LOW_S |
                                                              SCRIPT_VERIFY_WITNESS |
                                                              SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM |
-                                                             SCRIPT_VERIFY_WITNESS_PUBKEYTYPE;
+                                                             SCRIPT_VERIFY_WITNESS_PUBKEYTYPE |
+                                                             SCRIPT_VERIFY_CONST_SCRIPTCODE;
 
 /** For convenience, standard but not mandatory verify flags. */
 static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index e0d193fa38..13f41a7cbf 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -336,6 +336,10 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
                 opcode == OP_RSHIFT)
                 return set_error(serror, SCRIPT_ERR_DISABLED_OPCODE); // Disabled opcodes.
 
+            // With SCRIPT_VERIFY_CONST_SCRIPTCODE, OP_CODESEPARATOR in non-segwit script is rejected even in an unexecuted branch
+            if (opcode == OP_CODESEPARATOR && sigversion == SigVersion::BASE && (flags & SCRIPT_VERIFY_CONST_SCRIPTCODE))
+                return set_error(serror, SCRIPT_ERR_OP_CODESEPARATOR);
+
             if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) {
                 if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) {
                     return set_error(serror, SCRIPT_ERR_MINIMALDATA);
@@ -899,6 +903,9 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
 
                 case OP_CODESEPARATOR:
                 {
+                    // If SCRIPT_VERIFY_CONST_SCRIPTCODE flag is set, use of OP_CODESEPARATOR is rejected in pre-segwit
+                    // script, even in an unexecuted branch (this is checked above the opcode case statement).
+
                     // Hash starts after the code separator
                     pbegincodehash = pc;
                 }
@@ -919,7 +926,9 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
 
                     // Drop the signature in pre-segwit scripts but not segwit scripts
                     if (sigversion == SigVersion::BASE) {
-                        FindAndDelete(scriptCode, CScript(vchSig));
+                        int found = FindAndDelete(scriptCode, CScript(vchSig));
+                        if (found > 0 && (flags & SCRIPT_VERIFY_CONST_SCRIPTCODE))
+                            return set_error(serror, SCRIPT_ERR_SIG_FINDANDDELETE);
                     }
 
                     if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, sigversion, serror)) {
@@ -983,7 +992,9 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
                     {
                         valtype& vchSig = stacktop(-isig-k);
                         if (sigversion == SigVersion::BASE) {
-                            FindAndDelete(scriptCode, CScript(vchSig));
+                            int found = FindAndDelete(scriptCode, CScript(vchSig));
+                            if (found > 0 && (flags & SCRIPT_VERIFY_CONST_SCRIPTCODE))
+                                return set_error(serror, SCRIPT_ERR_SIG_FINDANDDELETE);
                         }
                     }
 
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index 50c747900a..2800473a68 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -111,6 +111,10 @@ enum
     // Public keys in segregated witness scripts must be compressed
     //
     SCRIPT_VERIFY_WITNESS_PUBKEYTYPE = (1U << 15),
+
+    // Making OP_CODESEPARATOR and FindAndDelete fail any non-segwit scripts
+    //
+    SCRIPT_VERIFY_CONST_SCRIPTCODE = (1U << 16),
 };
 
 bool CheckSignatureEncoding(const std::vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror);
diff --git a/src/script/script_error.cpp b/src/script/script_error.cpp
index dbceb1f740..ceda740580 100644
--- a/src/script/script_error.cpp
+++ b/src/script/script_error.cpp
@@ -89,6 +89,10 @@ const char* ScriptErrorString(const ScriptError serror)
             return "Witness provided for non-witness script";
         case SCRIPT_ERR_WITNESS_PUBKEYTYPE:
             return "Using non-compressed keys in segwit";
+        case SCRIPT_ERR_OP_CODESEPARATOR:
+            return "Using OP_CODESEPARATOR in non-witness script";
+        case SCRIPT_ERR_SIG_FINDANDDELETE:
+            return "Signature is found in scriptCode";
         case SCRIPT_ERR_UNKNOWN_ERROR:
         case SCRIPT_ERR_ERROR_COUNT:
         default: break;
diff --git a/src/script/script_error.h b/src/script/script_error.h
index 3200e94707..6982a087f4 100644
--- a/src/script/script_error.h
+++ b/src/script/script_error.h
@@ -64,6 +64,10 @@ typedef enum ScriptError_t
     SCRIPT_ERR_WITNESS_UNEXPECTED,
     SCRIPT_ERR_WITNESS_PUBKEYTYPE,
 
+    /* Constant scriptCode */
+    SCRIPT_ERR_OP_CODESEPARATOR,
+    SCRIPT_ERR_SIG_FINDANDDELETE,
+
     SCRIPT_ERR_ERROR_COUNT
 } ScriptError;
 
diff --git a/src/test/data/tx_invalid.json b/src/test/data/tx_invalid.json
index abb46fe533..918df6d8d9 100644
--- a/src/test/data/tx_invalid.json
+++ b/src/test/data/tx_invalid.json
@@ -340,5 +340,53 @@
 [[["9628667ad48219a169b41b020800162287d2c0f713c04157e95c484a8dcb7592", 7500, "0x00 0x20 0x9b66c15b4e0b4eb49fa877982cafded24859fe5b0e2dbfbe4f0df1de7743fd52", 200000]],
 "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", "P2SH,WITNESS"],
 
+["SCRIPT_VERIFY_CONST_SCRIPTCODE tests"],
+["All transactions are copied from OP_CODESEPARATOR tests in tx_valid.json"],
+
+[[["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"],
+
+["CODESEPARATOR in an unexecuted IF block is still invalid"],
+[[["a955032f4d6b0c9bfe8cad8f00a8933790b9c1dc28c82e0f48e75b35da0e4944", 0, "IF CODESEPARATOR ENDIF 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 CHECKSIGVERIFY CODESEPARATOR 1"]],
+  "010000000144490eda355be7480f2ec828dcc1b9903793a8008fad8cfe9b0c6b4d2f0355a9000000004a48304502207a6974a77c591fa13dff60cabbb85a0de9e025c09c65a4b2285e47ce8e22f761022100f0efaac9ff8ac36b10721e0aae1fb975c90500b50c56e8a0cc52b0403f0425dd0100ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+
+["CODESEPARATOR in an executed IF block is invalid"],
+[[["a955032f4d6b0c9bfe8cad8f00a8933790b9c1dc28c82e0f48e75b35da0e4944", 0, "IF CODESEPARATOR ENDIF 0x21 0x0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71 CHECKSIGVERIFY CODESEPARATOR 1"]],
+  "010000000144490eda355be7480f2ec828dcc1b9903793a8008fad8cfe9b0c6b4d2f0355a9000000004a483045022100fa4a74ba9fd59c59f46c3960cf90cbe0d2b743c471d24a3d5d6db6002af5eebb02204d70ec490fd0f7055a7c45f86514336e3a7f03503dacecabb247fc23f15c83510151ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+
+
+["Using CHECKSIG with singatures in scriptSigs will trigger FindAndDelete, which is invalid"],
+[[["ccf7f4053a02e653c36ac75c891b7496d0dc5ce5214f6c913d9cf8f1329ebee0", 0, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+  "0100000001e0be9e32f1f89c3d916c4f21e55cdcd096741b895cc76ac353e6023a05f4f7cc00000000d86149304602210086e5f736a2c3622ebb62bd9d93d8e5d76508b98be922b97160edc3dcca6d8c47022100b23c312ac232a4473f19d2aeb95ab7bdf2b65518911a0d72d50e38b5dd31dc820121038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041ac4730440220508fa761865c8abd81244a168392876ee1d94e8ed83897066b5e2df2400dad24022043f5ee7538e87e9c6aef7ef55133d3e51da7cc522830a9c4d736977a76ef755c0121038479a0fa998cd35259a2ef0a7a5c68662c1474f88ccb6d08a7677bbec7f22041ffffffff010000000000000000016a00000000", "P2SH,CONST_SCRIPTCODE"],
+
+["OP_CODESEPARATOR in scriptSig is invalid"],
+[[["10c9f0effe83e97f80f067de2b11c6a00c3088a4bce42c5ae761519af9306f3c", 1, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+  "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", "P2SH,CONST_SCRIPTCODE"],
+
+["Again, FindAndDelete() in scriptSig"],
+[[["6056ebd549003b10cbbd915cea0d82209fe40b8617104be917a26fa92cbe3d6f", 0, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+  "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", "P2SH,CONST_SCRIPTCODE"],
+
+[[["5a6b0021a6042a686b6b94abc36b387bef9109847774e8b1e51eb8cc55c53921", 1, "DUP HASH160 0x14 0xee5a6aa40facefb2655ac23c0c28c57c65c41f9b EQUALVERIFY CHECKSIG"]],
+  "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", "P2SH,CONST_SCRIPTCODE"],
+
+["FindAndDelete() in redeemScript"],
+[[["b5b598de91787439afd5938116654e0b16b7a0d0f82742ba37564219c5afcbf9", 0, "DUP HASH160 0x14 0xf6f365c40f0739b61de827a44751e5e99032ed8f EQUALVERIFY CHECKSIG"],
+  ["ab9805c6d57d7070d9a42c5176e47bb705023e6b67249fb6760880548298e742", 0, "HASH160 0x14 0xd8dacdadb7462ae15cd906f1878706d0da8660e6 EQUAL"]],
+  "0100000002f9cbafc519425637ba4227f8d0a0b7160b4e65168193d5af39747891de98b5b5000000006b4830450221008dd619c563e527c47d9bd53534a770b102e40faa87f61433580e04e271ef2f960220029886434e18122b53d5decd25f1f4acb2480659fea20aabd856987ba3c3907e0121022b78b756e2258af13779c1a1f37ea6800259716ca4b7f0b87610e0bf3ab52a01ffffffff42e7988254800876b69f24676b3e0205b77be476512ca4d970707dd5c60598ab00000000fd260100483045022015bd0139bcccf990a6af6ec5c1c52ed8222e03a0d51c334df139968525d2fcd20221009f9efe325476eb64c3958e4713e9eefe49bf1d820ed58d2112721b134e2a1a53034930460221008431bdfa72bc67f9d41fe72e94c88fb8f359ffa30b33c72c121c5a877d922e1002210089ef5fc22dd8bfc6bf9ffdb01a9862d27687d424d1fefbab9e9c7176844a187a014c9052483045022015bd0139bcccf990a6af6ec5c1c52ed8222e03a0d51c334df139968525d2fcd20221009f9efe325476eb64c3958e4713e9eefe49bf1d820ed58d2112721b134e2a1a5303210378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71210378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c7153aeffffffff01a08601000000000017a914d8dacdadb7462ae15cd906f1878706d0da8660e68700000000", "P2SH,CONST_SCRIPTCODE"],
+
+["FindAndDelete() in bare CHECKMULTISIG"],
+[[["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"]
 ]
diff --git a/src/test/data/tx_valid.json b/src/test/data/tx_valid.json
index 0bcecc58fe..4a1c77166d 100644
--- a/src/test/data/tx_valid.json
+++ b/src/test/data/tx_valid.json
@@ -477,17 +477,17 @@
 ["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"],
+"0100000000010280e68831516392fcd100d186b3c2c7b95c80b53c77e77c35ba03a66b429a2a1b0000000000ffffffffe9b542c5176808107ff1df906f46bb1f2583b16112b95ee5380665ba7fcfc0010000000000ffffffff0280969800000000001976a9146648a8cd4531e1ec47f35916de8e259237294d1e88ac80969800000000001976a914de4b231626ef508c9a74a8517e6783c0546d6b2888ac024730440220032521802a76ad7bf74d0e2c218b72cf0cbc867066e2e53db905ba37f130397e02207709e2188ed7f08f4c952d9d13986da504502b8c3be59617e043552f506c46ff83275163ab68210392972e2eb617b2388771abe27235fd5ac44af8e61693261550447a4c3e39da98ac02483045022100f6a10b8604e6dc910194b79ccfc93e1bc0ec7c03453caaa8987f7d6c3413566002206216229ede9b4d6ec2d325be245c5b508ff0339bf1794078e20bfe0babc7ffe683270063ab68210392972e2eb617b2388771abe27235fd5ac44af8e61693261550447a4c3e39da98ac00000000", "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]],
@@ -504,7 +504,7 @@
 "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"],
@@ -514,7 +514,7 @@
 "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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"],
 
 ["Test long outputs, which are streamed using length-prefixed bitcoin strings. This might be surprising."],
 [[["1111111111111111111111111111111111111111111111111111111111111111", 0, "0x00 0x14 0x751e76e8199196d454941c45d1b3a323f1433bd6", 5000000]],
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index f561660fef..33b31565a6 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -97,6 +97,8 @@ static ScriptErrorDesc script_errors[]={
     {SCRIPT_ERR_WITNESS_MALLEATED_P2SH, "WITNESS_MALLEATED_P2SH"},
     {SCRIPT_ERR_WITNESS_UNEXPECTED, "WITNESS_UNEXPECTED"},
     {SCRIPT_ERR_WITNESS_PUBKEYTYPE, "WITNESS_PUBKEYTYPE"},
+    {SCRIPT_ERR_OP_CODESEPARATOR, "OP_CODESEPARATOR"},
+    {SCRIPT_ERR_SIG_FINDANDDELETE, "SIG_FINDANDDELETE"},
 };
 
 static const char *FormatScriptError(ScriptError_t err)
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index c753e0a11d..cc72e96eb1 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -53,6 +53,7 @@ static std::map<std::string, unsigned int> mapFlagNames = {
     {std::string("WITNESS"), (unsigned int)SCRIPT_VERIFY_WITNESS},
     {std::string("DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM"), (unsigned int)SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM},
     {std::string("WITNESS_PUBKEYTYPE"), (unsigned int)SCRIPT_VERIFY_WITNESS_PUBKEYTYPE},
+    {std::string("CONST_SCRIPTCODE"), (unsigned int)SCRIPT_VERIFY_CONST_SCRIPTCODE},
 };
 
 unsigned int ParseScriptFlags(std::string strFlags)
diff --git a/src/validation.cpp b/src/validation.cpp
index 8a941561bb..cd5f9d8ec0 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -582,6 +582,12 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
     if (fRequireStandard && !IsStandardTx(tx, reason, witnessEnabled))
         return state.DoS(0, false, REJECT_NONSTANDARD, reason);
 
+    // Do not work on transactions that are too small.
+    // A transaction with 1 segwit input and 1 P2WPHK output has non-witness size of 82 bytes.
+    // Transactions smaller than this are not relayed to reduce unnecessary malloc overhead.
+    if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) < MIN_STANDARD_TX_NONWITNESS_SIZE)
+        return state.DoS(0, false, REJECT_NONSTANDARD, "tx-size-small");
+
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.