Merge #13424: Consistently validate txid / blockhash length and encoding in rpc calls

5eb20f81d9 Consistently use ParseHashV to validate hash inputs in rpc (Ben Woosley)

Pull request description:

  ParseHashV validates the length and encoding of the string and throws
  an informative RPC error on failure, which is as good or better than
  these alternative calls.

  Note I switched ParseHashV to check string length first, because
  IsHex tests that the length is even, and an error like:
  "must be of length 64 (not 63, for X)" is much more informative than
  "must be hexadecimal string (not X)" in that case.

  Split from #13420

Tree-SHA512: f0786b41c0d7793ff76e4b2bb35547873070bbf7561d510029e8edb93f59176277efcd4d183b3185532ea69fc0bbbf3dbe9e19362e8017007ae9d51266cd78ae

1 files changed, 9 insertions, 16 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 439427cd7e..47ee4fd6db 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -260,7 +260,7 @@ static UniValue waitforblock(const JSONRPCRequest& request)
         );
     int timeout = 0;
 
-    uint256 hash = uint256S(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     if (!request.params[1].isNull())
         timeout = request.params[1].get_int();
@@ -727,8 +727,7 @@ static UniValue getblockheader(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "hash"));
 
     bool fVerbose = true;
     if (!request.params[1].isNull())
@@ -822,8 +821,7 @@ static UniValue getblock(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     int verbosity = 1;
     if (!request.params[1].isNull()) {
@@ -1055,8 +1053,7 @@ UniValue gettxout(const JSONRPCRequest& request)
 
     UniValue ret(UniValue::VOBJ);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "txid"));
     int n = request.params[1].get_int();
     COutPoint out(hash, n);
     bool fMempool = true;
@@ -1464,8 +1461,7 @@ static UniValue preciousblock(const JSONRPCRequest& request)
             + HelpExampleRpc("preciousblock", "\"blockhash\"")
         );
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
     CBlockIndex* pblockindex;
 
     {
@@ -1500,8 +1496,7 @@ static UniValue invalidateblock(const JSONRPCRequest& request)
             + HelpExampleRpc("invalidateblock", "\"blockhash\"")
         );
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
     CValidationState state;
 
     {
@@ -1540,8 +1535,7 @@ static UniValue reconsiderblock(const JSONRPCRequest& request)
             + HelpExampleRpc("reconsiderblock", "\"blockhash\"")
         );
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     {
         LOCK(cs_main);
@@ -1594,7 +1588,7 @@ static UniValue getchaintxstats(const JSONRPCRequest& request)
         LOCK(cs_main);
         pindex = chainActive.Tip();
     } else {
-        uint256 hash = uint256S(request.params[1].get_str());
+        uint256 hash(ParseHashV(request.params[1], "blockhash"));
         LOCK(cs_main);
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
@@ -1768,8 +1762,7 @@ static UniValue getblockstats(const JSONRPCRequest& request)
 
         pindex = chainActive[height];
     } else {
-        const std::string strHash = request.params[0].get_str();
-        const uint256 hash(uint256S(strHash));
+        const uint256 hash(ParseHashV(request.params[0], "hash_or_height"));
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");