Implement SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS

Author: petertodd

bitcoin/core/scripteval.py

@@ -591,9 +591,15 @@ def check_args(n):
                 check_args(2)
                 del stack[-2]
 
-            elif sop == OP_NOP or (sop >= OP_NOP1 and sop <= OP_NOP10):
+            elif sop == OP_NOP:
                 pass
 
+            elif sop >= OP_NOP1 and sop <= OP_NOP10:
+                if SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS in flags:
+                    err_raiser(EvalScriptError, "%s reserved for soft-fork upgrades" % OPCODE_NAMES[sop])
+                else:
+                    pass
+
             elif sop == OP_OVER:
                 check_args(2)
                 vch = stack[-2]

bitcoin/tests/data/script_invalid.json

@@ -163,6 +163,23 @@
 ["1","NOP1 CHECKLOCKTIMEVERIFY NOP3 NOP4 NOP5 NOP6 NOP7 NOP8 NOP9 NOP10 2 EQUAL", "P2SH,STRICTENC"],
 ["'NOP_1_to_10' NOP1 CHECKLOCKTIMEVERIFY NOP3 NOP4 NOP5 NOP6 NOP7 NOP8 NOP9 NOP10","'NOP_1_to_11' EQUAL", "P2SH,STRICTENC"],
 
+["Ensure 100% coverage of discouraged NOPS"],
+["1", "NOP1",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "CHECKLOCKTIMEVERIFY",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP3",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP4",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP5",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP6",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP7",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP8",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP9",  "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+["1", "NOP10", "P2SH,DISCOURAGE_UPGRADABLE_NOPS"],
+
+["NOP10", "1", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "Discouraged NOP10 in scriptSig"],
+
+["1 0x01 0xb9", "HASH160 0x14 0x15727299b05b45fdaf9ac9ecf7565cfe27c3e567 EQUAL",
+ "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "Discouraged NOP10 in redeemScript"],
+
 ["0x50","1", "P2SH,STRICTENC", "opcode 0x50 is reserved"],
 ["1", "IF 0xba ELSE 1 ENDIF", "P2SH,STRICTENC", "opcodes above NOP10 invalid if executed"],
 ["1", "IF 0xbb ELSE 1 ENDIF", "P2SH,STRICTENC"],