Merge #610: All peg-out related detection pushes should be <= OP_PUSHDATA4

instagibbs · instagibbs · commit 1ccb0b67f976 · 2019-06-05T11:28:27.000+02:00
cff50f5 All peg-out related detection pushes should be <= OP_PUSHDATA4 (Gregory Sanders) Pull request description: related to #598 , #596, #597 This does not affect consensus, but affects consumers of these parsing rules such as rust-elements. cc @apoelstra @roconnor-blockstream Tree-SHA512: 4ab6f0be52c3804b2af43c7b3eecbbe8f2868d3f33385dc54f3acb0e441188018a2b3df197801f2c20fa96e224b6acacb642ecf2f030227618e0aea1e2da44ea
diff --git a/src/primitives/pak.cpp b/src/primitives/pak.cpp
@@ -185,7 +185,7 @@ bool ScriptHasValidPAKProof(const CScript& script, const uint256& genesis_hash)
     std::vector<unsigned char> extracted_pubkey_hash;
 
     // Get full pubkey
-    if (!script.GetOp(pc, opcode, data) || opcode != 33 || data.size() != 33) {
+    if (!script.GetOp(pc, opcode, data) || data.size() != 33 || opcode > OP_PUSHDATA4) {
         return false;
     }
     CPubKey full_pubkey(data.begin(), data.end());
diff --git a/src/script/script.cpp b/src/script/script.cpp
@@ -213,17 +213,24 @@ bool CScript::IsPegoutScript(uint256& genesis_hash, CScript& pegout_scriptpubkey
         return false;
     }
 
-    if (!GetOp(pc, opcode, data) || data.size() != 32 ) {
+    if (!GetOp(pc, opcode, data) || data.size() != 32 || opcode > OP_PUSHDATA4) {
         return false;
     }
     genesis_hash = uint256(data);
 
     // Read in parent chain destination scriptpubkey
-    if (!GetOp(pc, opcode, data) || data.size() == 0 ) {
+    if (!GetOp(pc, opcode, data) || opcode > OP_PUSHDATA4 ) {
         return false;
     }
     pegout_scriptpubkey = CScript(data.begin(), data.end());
 
+    // All extra opcodes must be pushes
+    while(GetOp(pc, opcode, data)) {
+        if (opcode > OP_PUSHDATA4) {
+            return false;
+        }
+    }
+
     return true;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -185,7 +185,7 @@ bool ScriptHasValidPAKProof(const CScript& script, const uint256& genesis_hash)`
`185`	`185`	`std::vector<unsigned char> extracted_pubkey_hash;`
`186`	`186`
`187`	`187`	`// Get full pubkey`
`188`		`- if (!script.GetOp(pc, opcode, data) \|\| opcode != 33 \|\| data.size() != 33) {`
	`188`	`+ if (!script.GetOp(pc, opcode, data) \|\| data.size() != 33 \|\| opcode > OP_PUSHDATA4) {`
`189`	`189`	`return false;`
`190`	`190`	`}`
`191`	`191`	`CPubKey full_pubkey(data.begin(), data.end());`
Original file line number	Diff line number	Diff line change
`@@ -213,17 +213,24 @@ bool CScript::IsPegoutScript(uint256& genesis_hash, CScript& pegout_scriptpubkey`
`213`	`213`	`return false;`
`214`	`214`	`}`
`215`	`215`
`216`		`- if (!GetOp(pc, opcode, data) \|\| data.size() != 32 ) {`
	`216`	`+ if (!GetOp(pc, opcode, data) \|\| data.size() != 32 \|\| opcode > OP_PUSHDATA4) {`
`217`	`217`	`return false;`
`218`	`218`	`}`
`219`	`219`	`genesis_hash = uint256(data);`
`220`	`220`
`221`	`221`	`// Read in parent chain destination scriptpubkey`
`222`		`- if (!GetOp(pc, opcode, data) \|\| data.size() == 0 ) {`
	`222`	`+ if (!GetOp(pc, opcode, data) \|\| opcode > OP_PUSHDATA4 ) {`
`223`	`223`	`return false;`
`224`	`224`	`}`
`225`	`225`	`pegout_scriptpubkey = CScript(data.begin(), data.end());`
`226`	`226`
	`227`	`+ // All extra opcodes must be pushes`
	`228`	`+ while(GetOp(pc, opcode, data)) {`
	`229`	`+ if (opcode > OP_PUSHDATA4) {`
	`230`	`+ return false;`
	`231`	`+ }`
	`232`	`+ }`
	`233`	`+`
`227`	`234`	`return true;`
`228`	`235`	`}`
`229`	`236`