1 files changed, 113 insertions, 0 deletions
diff --git a/src/rpc/signmessage.cpp b/src/rpc/signmessage.cpp
new file mode 100644
index 0000000000..8c752ba1fd
--- /dev/null
+++ b/src/rpc/signmessage.cpp
@@ -0,0 +1,113 @@
+// Copyright (c) 2010 Satoshi Nakamoto
+// Copyright (c) 2009-2022 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 <key.h>
+#include <key_io.h>
+#include <rpc/protocol.h>
+#include <rpc/request.h>
+#include <rpc/server.h>
+#include <rpc/util.h>
+#include <univalue.h>
+#include <util/message.h>
+
+#include <string>
+
+static RPCHelpMan verifymessage()
+{
+    return RPCHelpMan{"verifymessage",
+        "Verify a signed message.",
+        {
+            {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The bitcoin address to use for the signature."},
+            {"signature", RPCArg::Type::STR, RPCArg::Optional::NO, "The signature provided by the signer in base 64 encoding (see signmessage)."},
+            {"message", RPCArg::Type::STR, RPCArg::Optional::NO, "The message that was signed."},
+        },
+        RPCResult{
+            RPCResult::Type::BOOL, "", "If the signature is verified or not."
+        },
+        RPCExamples{
+            "\nUnlock the wallet for 30 seconds\n"
+            + HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +
+            "\nCreate the signature\n"
+            + HelpExampleCli("signmessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"my message\"") +
+            "\nVerify the signature\n"
+            + HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"signature\" \"my message\"") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"signature\", \"my message\"")
+        },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            std::string strAddress = request.params[0].get_str();
+            std::string strSign = request.params[1].get_str();
+            std::string strMessage = request.params[2].get_str();
+
+            switch (MessageVerify(strAddress, strSign, strMessage)) {
+            case MessageVerificationResult::ERR_INVALID_ADDRESS:
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
+            case MessageVerificationResult::ERR_ADDRESS_NO_KEY:
+                throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
+            case MessageVerificationResult::ERR_MALFORMED_SIGNATURE:
+                throw JSONRPCError(RPC_TYPE_ERROR, "Malformed base64 encoding");
+            case MessageVerificationResult::ERR_PUBKEY_NOT_RECOVERED:
+            case MessageVerificationResult::ERR_NOT_SIGNED:
+                return false;
+            case MessageVerificationResult::OK:
+                return true;
+            }
+
+            return false;
+        },
+    };
+}
+
+static RPCHelpMan signmessagewithprivkey()
+{
+    return RPCHelpMan{"signmessagewithprivkey",
+        "\nSign a message with the private key of an address\n",
+        {
+            {"privkey", RPCArg::Type::STR, RPCArg::Optional::NO, "The private key to sign the message with."},
+            {"message", RPCArg::Type::STR, RPCArg::Optional::NO, "The message to create a signature of."},
+        },
+        RPCResult{
+            RPCResult::Type::STR, "signature", "The signature of the message encoded in base 64"
+        },
+        RPCExamples{
+            "\nCreate the signature\n"
+            + HelpExampleCli("signmessagewithprivkey", "\"privkey\" \"my message\"") +
+            "\nVerify the signature\n"
+            + HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"signature\" \"my message\"") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("signmessagewithprivkey", "\"privkey\", \"my message\"")
+        },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            std::string strPrivkey = request.params[0].get_str();
+            std::string strMessage = request.params[1].get_str();
+
+            CKey key = DecodeSecret(strPrivkey);
+            if (!key.IsValid()) {
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid private key");
+            }
+
+            std::string signature;
+
+            if (!MessageSign(key, strMessage, signature)) {
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Sign failed");
+            }
+
+            return signature;
+        },
+    };
+}
+
+void RegisterSignMessageRPCCommands(CRPCTable& t)
+{
+    static const CRPCCommand commands[]{
+        {"util", &verifymessage},
+        {"util", &signmessagewithprivkey},
+    };
+    for (const auto& c : commands) {
+        t.appendCommand(c.name, &c);
+    }
+}