Merge bitcoin#13424: Consistently validate txid / blockhash length an…

…d encoding in rpc calls

5eb20f8 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 bitcoin#13420

Tree-SHA512: f0786b41c0d7793ff76e4b2bb35547873070bbf7561d510029e8edb93f59176277efcd4d183b3185532ea69fc0bbbf3dbe9e19362e8017007ae9d51266cd78ae

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");

src/rpc/mining.cpp

@@ -247,7 +247,7 @@ static UniValue prioritisetransaction(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    uint256 hash = ParseHashStr(request.params[0].get_str(), "txid");
+    uint256 hash(ParseHashV(request.params[0], "txid"));
     CAmount nAmount = request.params[2].get_int64();
 
     if (!(request.params[1].isNull() || request.params[1].get_real() == 0)) {
@@ -455,7 +455,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
             // Format: <hashBestChain><nTransactionsUpdatedLast>
             std::string lpstr = lpval.get_str();
 
-            hashWatchedChain.SetHex(lpstr.substr(0, 64));
+            hashWatchedChain = ParseHashV(lpstr.substr(0, 64), "longpollid");
             nTransactionsUpdatedLastLP = atoi64(lpstr.substr(64));
         }
         else

src/rpc/rawtransaction.cpp

@@ -226,9 +226,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     UniValue txids = request.params[0].get_array();
     for (unsigned int idx = 0; idx < txids.size(); idx++) {
         const UniValue& txid = txids[idx];
-        if (txid.get_str().length() != 64 || !IsHex(txid.get_str()))
-            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid txid ")+txid.get_str());
-        uint256 hash(uint256S(txid.get_str()));
+        uint256 hash(ParseHashV(txid, "txid"));
         if (setTxids.count(hash))
             throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ")+txid.get_str());
        setTxids.insert(hash);
@@ -239,7 +237,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     uint256 hashBlock;
     if (!request.params[1].isNull()) {
         LOCK(cs_main);
-        hashBlock = uint256S(request.params[1].get_str());
+        hashBlock = ParseHashV(request.params[1], "blockhash");
         pblockindex = LookupBlockIndex(hashBlock);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");

src/rpc/server.cpp

@@ -116,16 +116,12 @@ CAmount AmountFromValue(const UniValue& value)
 
 uint256 ParseHashV(const UniValue& v, std::string strName)
 {
-    std::string strHex;
-    if (v.isStr())
-        strHex = v.get_str();
+    std::string strHex(v.get_str());
+    if (64 != strHex.length())
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s must be of length %d (not %d, for '%s')", strName, 64, strHex.length(), strHex));
     if (!IsHex(strHex)) // Note: IsHex("") is false
         throw JSONRPCError(RPC_INVALID_PARAMETER, strName+" must be hexadecimal string (not '"+strHex+"')");
-    if (64 != strHex.length())
-        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s must be of length %d (not %d)", strName, 64, strHex.length()));
-    uint256 result;
-    result.SetHex(strHex);
-    return result;
+    return uint256S(strHex);
 }
 uint256 ParseHashO(const UniValue& o, std::string strKey)
 {

src/wallet/rpcdump.cpp

@@ -415,8 +415,7 @@ UniValue removeprunedfunds(const JSONRPCRequest& request)
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
     std::vector<uint256> vHash;
     vHash.push_back(hash);
     std::vector<uint256> vHashOut;

src/wallet/rpcwallet.cpp

@@ -1638,9 +1638,8 @@ static UniValue listsinceblock(const JSONRPCRequest& request)
     isminefilter filter = ISMINE_SPENDABLE;
 
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
-        uint256 blockId;
+        uint256 blockId(ParseHashV(request.params[0], "blockhash"));
 
-        blockId.SetHex(request.params[0].get_str());
         paltindex = pindex = LookupBlockIndex(blockId);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
@@ -1768,8 +1767,7 @@ static UniValue gettransaction(const JSONRPCRequest& request)
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
 
     isminefilter filter = ISMINE_SPENDABLE;
     if(!request.params[1].isNull())
@@ -1836,8 +1834,7 @@ static UniValue abandontransaction(const JSONRPCRequest& request)
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
 
     if (!pwallet->mapWallet.count(hash)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid or non-wallet transaction id");
@@ -2241,17 +2238,13 @@ static UniValue lockunspent(const JSONRPCRequest& request)
                 {"vout", UniValueType(UniValue::VNUM)},
             });
 
-        const std::string& txid = find_value(o, "txid").get_str();
-        if (!IsHex(txid)) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected hex txid");
-        }
-
+        const uint256 txid(ParseHashO(o, "txid"));
         const int nOutput = find_value(o, "vout").get_int();
         if (nOutput < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout must be positive");
         }
 
-        const COutPoint outpt(uint256S(txid), nOutput);
+        const COutPoint outpt(txid, nOutput);
 
         const auto it = pwallet->mapWallet.find(outpt.hash);
         if (it == pwallet->mapWallet.end()) {
@@ -3176,8 +3169,7 @@ static UniValue bumpfee(const JSONRPCRequest& request)
     }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VOBJ});
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
 
     // optional parameters
     CAmount totalFee = 0;

test/functional/mining_prioritisetransaction.py

@@ -29,7 +29,8 @@ def run_test(self):
         assert_raises_rpc_error(-1, "prioritisetransaction", self.nodes[0].prioritisetransaction, '', 0, 0, 0)
 
         # Test `prioritisetransaction` invalid `txid`
-        assert_raises_rpc_error(-1, "txid must be hexadecimal string", self.nodes[0].prioritisetransaction, txid='foo', fee_delta=0)
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 3, for 'foo')", self.nodes[0].prioritisetransaction, txid='foo', fee_delta=0)
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'Zd1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000')", self.nodes[0].prioritisetransaction, txid='Zd1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000', fee_delta=0)
 
         # Test `prioritisetransaction` invalid `dummy`
         txid = '1d1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000'

test/functional/p2p_compactblocks.py

@@ -293,7 +293,7 @@ def test_compactblock_construction(self, node, test_node, version, use_witness_a
         block_hash = int(node.generate(1)[0], 16)
 
         # Store the raw block in our internal format.
-        block = FromHex(CBlock(), node.getblock("%02x" % block_hash, False))
+        block = FromHex(CBlock(), node.getblock("%064x" % block_hash, False))
         for tx in block.vtx:
             tx.calc_sha256()
         block.rehash()

test/functional/p2p_sendheaders.py

@@ -402,7 +402,7 @@ def test_nonnull_locators(self, test_node, inv_node):
 
             block_time += 9
 
-            fork_point = self.nodes[0].getblock("%02x" % new_block_hashes[0])["previousblockhash"]
+            fork_point = self.nodes[0].getblock("%064x" % new_block_hashes[0])["previousblockhash"]
             fork_point = int(fork_point, 16)
 
             # Use getblocks/getdata

test/functional/rpc_blockchain.py

@@ -125,7 +125,9 @@ def _test_getchaintxstats(self):
 
         # Test `getchaintxstats` invalid `blockhash`
         assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getchaintxstats, blockhash=0)
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getchaintxstats, blockhash='0')
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 1, for '0')", self.nodes[0].getchaintxstats, blockhash='0')
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].getchaintxstats, blockhash='ZZZ0000000000000000000000000000000000000000000000000000000000000')
+        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getchaintxstats, blockhash='0000000000000000000000000000000000000000000000000000000000000000')
         blockhash = self.nodes[0].getblockhash(200)
         self.nodes[0].invalidateblock(blockhash)
         assert_raises_rpc_error(-8, "Block is not in main chain", self.nodes[0].getchaintxstats, blockhash=blockhash)
@@ -203,7 +205,9 @@ def _test_gettxoutsetinfo(self):
     def _test_getblockheader(self):
         node = self.nodes[0]
 
-        assert_raises_rpc_error(-5, "Block not found", node.getblockheader, "nonsense")
+        assert_raises_rpc_error(-8, "hash must be of length 64 (not 8, for 'nonsense')", node.getblockheader, "nonsense")
+        assert_raises_rpc_error(-8, "hash must be hexadecimal string (not 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844')", node.getblockheader, "ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844")
+        assert_raises_rpc_error(-5, "Block not found", node.getblockheader, "0cf7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844")
 
         besthash = node.getbestblockhash()
         secondbesthash = node.getblockhash(199)

test/functional/rpc_rawtransaction.py

@@ -80,8 +80,9 @@ def run_test(self):
         txid = '1d1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000'
         assert_raises_rpc_error(-3, "Expected type array", self.nodes[0].createrawtransaction, 'foo', {})
         assert_raises_rpc_error(-1, "JSON value is not an object as expected", self.nodes[0].createrawtransaction, ['foo'], {})
-        assert_raises_rpc_error(-8, "txid must be hexadecimal string", self.nodes[0].createrawtransaction, [{}], {})
-        assert_raises_rpc_error(-8, "txid must be hexadecimal string", self.nodes[0].createrawtransaction, [{'txid': 'foo'}], {})
+        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].createrawtransaction, [{}], {})
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 3, for 'foo')", self.nodes[0].createrawtransaction, [{'txid': 'foo'}], {})
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844')", self.nodes[0].createrawtransaction, [{'txid': 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844'}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, missing vout key", self.nodes[0].createrawtransaction, [{'txid': txid}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, missing vout key", self.nodes[0].createrawtransaction, [{'txid': txid, 'vout': 'foo'}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, vout must be positive", self.nodes[0].createrawtransaction, [{'txid': txid, 'vout': -1}], {})
@@ -224,9 +225,10 @@ def run_test(self):
         # We should not get the tx if we provide an unrelated block
         assert_raises_rpc_error(-5, "No such transaction found", self.nodes[0].getrawtransaction, tx, True, block2)
         # An invalid block hash should raise the correct errors
-        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal", self.nodes[0].getrawtransaction, tx, True, True)
-        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal", self.nodes[0].getrawtransaction, tx, True, "foobar")
-        assert_raises_rpc_error(-8, "parameter 3 must be of length 64", self.nodes[0].getrawtransaction, tx, True, "abcd1234")
+        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getrawtransaction, tx, True, True)
+        assert_raises_rpc_error(-8, "parameter 3 must be of length 64 (not 6, for 'foobar')", self.nodes[0].getrawtransaction, tx, True, "foobar")
+        assert_raises_rpc_error(-8, "parameter 3 must be of length 64 (not 8, for 'abcd1234')", self.nodes[0].getrawtransaction, tx, True, "abcd1234")
+        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].getrawtransaction, tx, True, "ZZZ0000000000000000000000000000000000000000000000000000000000000")
         assert_raises_rpc_error(-5, "Block hash not found", self.nodes[0].getrawtransaction, tx, True, "0000000000000000000000000000000000000000000000000000000000000000")
         # Undo the blocks and check in_active_chain
         self.nodes[0].invalidateblock(block1)

test/functional/rpc_txoutproof.py

@@ -66,12 +66,18 @@ def run_test(self):
         txid_spent = txin_spent["txid"]
         txid_unspent = txid1 if txin_spent["txid"] != txid1 else txid2
 
+        # Invalid txids
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 32, for '00000000000000000000000000000000')", self.nodes[2].gettxoutproof, ["00000000000000000000000000000000"], blockhash)
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[2].gettxoutproof, ["ZZZ0000000000000000000000000000000000000000000000000000000000000"], blockhash)
+        # Invalid blockhashes
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 32, for '00000000000000000000000000000000')", self.nodes[2].gettxoutproof, [txid_spent], "00000000000000000000000000000000")
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[2].gettxoutproof, [txid_spent], "ZZZ0000000000000000000000000000000000000000000000000000000000000")
         # We can't find the block from a fully-spent tx
         assert_raises_rpc_error(-5, "Transaction not yet in block", self.nodes[2].gettxoutproof, [txid_spent])
         # We can get the proof if we specify the block
         assert_equal(self.nodes[2].verifytxoutproof(self.nodes[2].gettxoutproof([txid_spent], blockhash)), [txid_spent])
         # We can't get the proof if we specify a non-existent block
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[2].gettxoutproof, [txid_spent], "00000000000000000000000000000000")
+        assert_raises_rpc_error(-5, "Block not found", self.nodes[2].gettxoutproof, [txid_spent], "0000000000000000000000000000000000000000000000000000000000000000")
         # We can get the proof if the transaction is unspent
         assert_equal(self.nodes[2].verifytxoutproof(self.nodes[2].gettxoutproof([txid_unspent])), [txid_unspent])
         # We can get the proof if we provide a list of transactions and one of them is unspent. The ordering of the list should not matter.

test/functional/wallet_basic.py

@@ -134,9 +134,15 @@ def run_test(self):
         assert_equal([unspent_0], self.nodes[2].listlockunspent())
         self.nodes[2].lockunspent(True, [unspent_0])
         assert_equal(len(self.nodes[2].listlockunspent()), 0)
-        assert_raises_rpc_error(-8, "Invalid parameter, unknown transaction",
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 34, for '0000000000000000000000000000000000')",
                                 self.nodes[2].lockunspent, False,
                                 [{"txid": "0000000000000000000000000000000000", "vout": 0}])
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')",
+                                self.nodes[2].lockunspent, False,
+                                [{"txid": "ZZZ0000000000000000000000000000000000000000000000000000000000000", "vout": 0}])
+        assert_raises_rpc_error(-8, "Invalid parameter, unknown transaction",
+                                self.nodes[2].lockunspent, False,
+                                [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0}])
         assert_raises_rpc_error(-8, "Invalid parameter, vout index out of bounds",
                                 self.nodes[2].lockunspent, False,
                                 [{"txid": unspent_0["txid"], "vout": 999}])

test/functional/wallet_listsinceblock.py

@@ -53,8 +53,10 @@ def test_invalid_blockhash(self):
                                 "42759cde25462784395a337460bde75f58e73d3f08bd31fdc3507cbac856a2c4")
         assert_raises_rpc_error(-5, "Block not found", self.nodes[0].listsinceblock,
                                 "0000000000000000000000000000000000000000000000000000000000000000")
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].listsinceblock,
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 11, for 'invalid-hex')", self.nodes[0].listsinceblock,
                                 "invalid-hex")
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'Z000000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].listsinceblock,
+                                "Z000000000000000000000000000000000000000000000000000000000000000")
 
     def test_reorg(self):
         '''