rpc: use `HexToPubKey` helper for all legacy pubkey-parsing RPCs

This deduplicates code and leads to more consistent and detailed error
messages. Affected are legacy import RPCs (`importpubkey`,
`importmulti`) and other ones where solving data can be provided
(`fundrawtransaction`, `walletcreatefundedpsbt`, `send`, `sendall`).

2 files changed, 3 insertions, 24 deletions

diff --git a/src/wallet/rpc/backup.cpp b/src/wallet/rpc/backup.cpp
index 99c548bf1d..d17a220603 100644
--- a/src/wallet/rpc/backup.cpp
+++ b/src/wallet/rpc/backup.cpp
@@ -460,12 +460,7 @@ RPCHelpMan importpubkey()
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");
     }
 
-    if (!IsHex(request.params[0].get_str()))
-        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey must be a hex string");
-    std::vector<unsigned char> data(ParseHex(request.params[0].get_str()));
-    CPubKey pubKey(data);
-    if (!pubKey.IsFullyValid())
-        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey is not a valid public key");
+    CPubKey pubKey = HexToPubKey(request.params[0].get_str());
 
     {
         LOCK(pwallet->cs_wallet);
@@ -986,15 +981,7 @@ static UniValue ProcessImportLegacy(ImportData& import_data, std::map<CKeyID, CP
         import_data.witnessscript = std::make_unique<CScript>(parsed_witnessscript.begin(), parsed_witnessscript.end());
     }
     for (size_t i = 0; i < pubKeys.size(); ++i) {
-        const auto& str = pubKeys[i].get_str();
-        if (!IsHex(str)) {
-            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey \"" + str + "\" must be a hex string");
-        }
-        auto parsed_pubkey = ParseHex(str);
-        CPubKey pubkey(parsed_pubkey);
-        if (!pubkey.IsFullyValid()) {
-            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey \"" + str + "\" is not a valid public key");
-        }
+        CPubKey pubkey = HexToPubKey(pubKeys[i].get_str());
         pubkey_map.emplace(pubkey.GetID(), pubkey);
         ordered_pubkeys.push_back(pubkey.GetID());
     }
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 6060f017ce..1a364a75ed 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -627,15 +627,7 @@ CreatedTransactionResult FundTransaction(CWallet& wallet, const CMutableTransact
         const UniValue solving_data = options["solving_data"].get_obj();
         if (solving_data.exists("pubkeys")) {
             for (const UniValue& pk_univ : solving_data["pubkeys"].get_array().getValues()) {
-                const std::string& pk_str = pk_univ.get_str();
-                if (!IsHex(pk_str)) {
-                    throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("'%s' is not hex", pk_str));
-                }
-                const std::vector<unsigned char> data(ParseHex(pk_str));
-                const CPubKey pubkey(data.begin(), data.end());
-                if (!pubkey.IsFullyValid()) {
-                    throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("'%s' is not a valid public key", pk_str));
-                }
+                const CPubKey pubkey = HexToPubKey(pk_univ.get_str());
                 coinControl.m_external_provider.pubkeys.emplace(pubkey.GetID(), pubkey);
                 // Add witness script for pubkeys
                 const CScript wit_script = GetScriptForDestination(WitnessV0KeyHash(pubkey));