3 files changed, 161 insertions, 1 deletions
diff --git a/src/wallet/rpc/signmessage.cpp b/src/wallet/rpc/signmessage.cpp
index 275eb2f1f7..bb8d7fc13f 100644
--- a/src/wallet/rpc/signmessage.cpp
+++ b/src/wallet/rpc/signmessage.cpp
@@ -5,7 +5,7 @@
 #include <key_io.h>
 #include <rpc/util.h>
 #include <util/message.h>
-#include <wallet/rpcwallet.h>
+#include <wallet/rpc/util.h>
 #include <wallet/wallet.h>
 
 #include <univalue.h>
diff --git a/src/wallet/rpc/util.cpp b/src/wallet/rpc/util.cpp
new file mode 100644
index 0000000000..b926bfc75f
--- /dev/null
+++ b/src/wallet/rpc/util.cpp
@@ -0,0 +1,122 @@
+// Copyright (c) 2011-2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <wallet/rpc/util.h>
+
+#include <rpc/util.h>
+#include <util/url.h>
+#include <wallet/context.h>
+#include <wallet/wallet.h>
+
+#include <univalue.h>
+
+static const std::string WALLET_ENDPOINT_BASE = "/wallet/";
+const std::string HELP_REQUIRING_PASSPHRASE{"\nRequires wallet passphrase to be set with walletpassphrase call if wallet is encrypted.\n"};
+
+bool GetAvoidReuseFlag(const CWallet& wallet, const UniValue& param) {
+    bool can_avoid_reuse = wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
+    bool avoid_reuse = param.isNull() ? can_avoid_reuse : param.get_bool();
+
+    if (avoid_reuse && !can_avoid_reuse) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "wallet does not have the \"avoid reuse\" feature enabled");
+    }
+
+    return avoid_reuse;
+}
+
+/** Used by RPC commands that have an include_watchonly parameter.
+ *  We default to true for watchonly wallets if include_watchonly isn't
+ *  explicitly set.
+ */
+bool ParseIncludeWatchonly(const UniValue& include_watchonly, const CWallet& wallet)
+{
+    if (include_watchonly.isNull()) {
+        // if include_watchonly isn't explicitly set, then check if we have a watchonly wallet
+        return wallet.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
+    }
+
+    // otherwise return whatever include_watchonly was set to
+    return include_watchonly.get_bool();
+}
+
+bool GetWalletNameFromJSONRPCRequest(const JSONRPCRequest& request, std::string& wallet_name)
+{
+    if (URL_DECODE && request.URI.substr(0, WALLET_ENDPOINT_BASE.size()) == WALLET_ENDPOINT_BASE) {
+        // wallet endpoint was used
+        wallet_name = URL_DECODE(request.URI.substr(WALLET_ENDPOINT_BASE.size()));
+        return true;
+    }
+    return false;
+}
+
+std::shared_ptr<CWallet> GetWalletForJSONRPCRequest(const JSONRPCRequest& request)
+{
+    CHECK_NONFATAL(request.mode == JSONRPCRequest::EXECUTE);
+    WalletContext& context = EnsureWalletContext(request.context);
+
+    std::string wallet_name;
+    if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
+        const std::shared_ptr<CWallet> pwallet = GetWallet(context, wallet_name);
+        if (!pwallet) throw JSONRPCError(RPC_WALLET_NOT_FOUND, "Requested wallet does not exist or is not loaded");
+        return pwallet;
+    }
+
+    std::vector<std::shared_ptr<CWallet>> wallets = GetWallets(context);
+    if (wallets.size() == 1) {
+        return wallets[0];
+    }
+
+    if (wallets.empty()) {
+        throw JSONRPCError(
+            RPC_WALLET_NOT_FOUND, "No wallet is loaded. Load a wallet using loadwallet or create a new one with createwallet. (Note: A default wallet is no longer automatically created)");
+    }
+    throw JSONRPCError(RPC_WALLET_NOT_SPECIFIED,
+        "Wallet file not specified (must request wallet RPC through /wallet/<filename> uri-path).");
+}
+
+void EnsureWalletIsUnlocked(const CWallet& wallet)
+{
+    if (wallet.IsLocked()) {
+        throw JSONRPCError(RPC_WALLET_UNLOCK_NEEDED, "Error: Please enter the wallet passphrase with walletpassphrase first.");
+    }
+}
+
+WalletContext& EnsureWalletContext(const std::any& context)
+{
+    auto wallet_context = util::AnyPtr<WalletContext>(context);
+    if (!wallet_context) {
+        throw JSONRPCError(RPC_INTERNAL_ERROR, "Wallet context not found");
+    }
+    return *wallet_context;
+}
+
+// also_create should only be set to true only when the RPC is expected to add things to a blank wallet and make it no longer blank
+LegacyScriptPubKeyMan& EnsureLegacyScriptPubKeyMan(CWallet& wallet, bool also_create)
+{
+    LegacyScriptPubKeyMan* spk_man = wallet.GetLegacyScriptPubKeyMan();
+    if (!spk_man && also_create) {
+        spk_man = wallet.GetOrCreateLegacyScriptPubKeyMan();
+    }
+    if (!spk_man) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "This type of wallet does not support this command");
+    }
+    return *spk_man;
+}
+
+const LegacyScriptPubKeyMan& EnsureConstLegacyScriptPubKeyMan(const CWallet& wallet)
+{
+    const LegacyScriptPubKeyMan* spk_man = wallet.GetLegacyScriptPubKeyMan();
+    if (!spk_man) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "This type of wallet does not support this command");
+    }
+    return *spk_man;
+}
+
+std::string LabelFromValue(const UniValue& value)
+{
+    std::string label = value.get_str();
+    if (label == "*")
+        throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME, "Invalid label name");
+    return label;
+}
diff --git a/src/wallet/rpc/util.h b/src/wallet/rpc/util.h
new file mode 100644
index 0000000000..a493a80a74
--- /dev/null
+++ b/src/wallet/rpc/util.h
@@ -0,0 +1,38 @@
+// Copyright (c) 2017-2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WALLET_RPC_UTIL_H
+#define BITCOIN_WALLET_RPC_UTIL_H
+
+#include <any>
+#include <memory>
+#include <string>
+
+class CWallet;
+class JSONRPCRequest;
+class LegacyScriptPubKeyMan;
+class UniValue;
+struct WalletContext;
+
+extern const std::string HELP_REQUIRING_PASSPHRASE;
+
+/**
+ * Figures out what wallet, if any, to use for a JSONRPCRequest.
+ *
+ * @param[in] request JSONRPCRequest that wishes to access a wallet
+ * @return nullptr if no wallet should be used, or a pointer to the CWallet
+ */
+std::shared_ptr<CWallet> GetWalletForJSONRPCRequest(const JSONRPCRequest& request);
+bool GetWalletNameFromJSONRPCRequest(const JSONRPCRequest& request, std::string& wallet_name);
+
+void EnsureWalletIsUnlocked(const CWallet&);
+WalletContext& EnsureWalletContext(const std::any& context);
+LegacyScriptPubKeyMan& EnsureLegacyScriptPubKeyMan(CWallet& wallet, bool also_create = false);
+const LegacyScriptPubKeyMan& EnsureConstLegacyScriptPubKeyMan(const CWallet& wallet);
+
+bool GetAvoidReuseFlag(const CWallet& wallet, const UniValue& param);
+bool ParseIncludeWatchonly(const UniValue& include_watchonly, const CWallet& wallet);
+std::string LabelFromValue(const UniValue& value);
+
+#endif // BITCOIN_WALLET_RPC_UTIL_H