1  // Copyright (c) 2011-present The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <common/signmessage.h>
 6  #include <key_io.h>
 7  #include <rpc/util.h>
 8  #include <wallet/rpc/util.h>
 9  #include <wallet/wallet.h>
10  
11  #include <univalue.h>
12  
13  namespace wallet {
14  RPCHelpMan signmessage()
15  {
16      return RPCHelpMan{
17          "signmessage",
18          "Sign a message with the private key of an address" +
19            HELP_REQUIRING_PASSPHRASE,
20          {
21              {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The bitcoin address to use for the private key."},
22              {"message", RPCArg::Type::STR, RPCArg::Optional::NO, "The message to create a signature of."},
23          },
24          RPCResult{
25              RPCResult::Type::STR, "signature", "The signature of the message encoded in base 64"
26          },
27          RPCExamples{
28              "\nUnlock the wallet for 30 seconds\n"
29              + HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +
30              "\nCreate the signature\n"
31              + HelpExampleCli("signmessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"my message\"") +
32              "\nVerify the signature\n"
33              + HelpExampleCli("verifymessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\" \"signature\" \"my message\"") +
34              "\nAs a JSON-RPC call\n"
35              + HelpExampleRpc("signmessage", "\"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX\", \"my message\"")
36          },
37          [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
38          {
39              const std::shared_ptr<const CWallet> pwallet = GetWalletForJSONRPCRequest(request);
40              if (!pwallet) return UniValue::VNULL;
41  
42              LOCK(pwallet->cs_wallet);
43  
44              EnsureWalletIsUnlocked(*pwallet);
45  
46              std::string strAddress = request.params[0].get_str();
47              std::string strMessage = request.params[1].get_str();
48  
49              CTxDestination dest = DecodeDestination(strAddress);
50              if (!IsValidDestination(dest)) {
51                  throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
52              }
53  
54              const PKHash* pkhash = std::get_if<PKHash>(&dest);
55              if (!pkhash) {
56                  throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
57              }
58  
59              std::string signature;
60              SigningResult err = pwallet->SignMessage(strMessage, *pkhash, signature);
61              if (err == SigningResult::SIGNING_FAILED) {
62                  throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, SigningResultString(err));
63              } else if (err != SigningResult::OK) {
64                  throw JSONRPCError(RPC_WALLET_ERROR, SigningResultString(err));
65              }
66  
67              return signature;
68          },
69      };
70  }
71  } // namespace wallet