1  // Copyright (c) 2020-2022 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 <chainparams.h>
 6  #include <common/args.h>
 7  #include <common/system.h>
 8  #include <external_signer.h>
 9  #include <wallet/external_signer_scriptpubkeyman.h>
10  
11  #include <iostream>
12  #include <memory>
13  #include <stdexcept>
14  #include <string>
15  #include <utility>
16  #include <vector>
17  
18  namespace wallet {
19  bool ExternalSignerScriptPubKeyMan::SetupDescriptor(WalletBatch& batch, std::unique_ptr<Descriptor> desc)
20  {
21      LOCK(cs_desc_man);
22      assert(m_storage.IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS));
23      assert(m_storage.IsWalletFlagSet(WALLET_FLAG_EXTERNAL_SIGNER));
24  
25      int64_t creation_time = GetTime();
26  
27      // Make the descriptor
28      WalletDescriptor w_desc(std::move(desc), creation_time, 0, 0, 0);
29      m_wallet_descriptor = w_desc;
30  
31      // Store the descriptor
32      if (!batch.WriteDescriptor(GetID(), m_wallet_descriptor)) {
33          throw std::runtime_error(std::string(__func__) + ": writing descriptor failed");
34      }
35  
36      // TopUp
37      TopUpWithDB(batch);
38  
39      m_storage.UnsetBlankWalletFlag(batch);
40      return true;
41  }
42  
43  ExternalSigner ExternalSignerScriptPubKeyMan::GetExternalSigner() {
44      const std::string command = gArgs.GetArg("-signer", "");
45      if (command == "") throw std::runtime_error(std::string(__func__) + ": restart bitcoind with -signer=<cmd>");
46      std::vector<ExternalSigner> signers;
47      ExternalSigner::Enumerate(command, signers, Params().GetChainTypeString());
48      if (signers.empty()) throw std::runtime_error(std::string(__func__) + ": No external signers found");
49      // TODO: add fingerprint argument instead of failing in case of multiple signers.
50      if (signers.size() > 1) throw std::runtime_error(std::string(__func__) + ": More than one external signer found. Please connect only one at a time.");
51      return signers[0];
52  }
53  
54  bool ExternalSignerScriptPubKeyMan::DisplayAddress(const CScript scriptPubKey, const ExternalSigner &signer) const
55  {
56      // TODO: avoid the need to infer a descriptor from inside a descriptor wallet
57      auto provider = GetSolvingProvider(scriptPubKey);
58      auto descriptor = InferDescriptor(scriptPubKey, *provider);
59  
60      signer.DisplayAddress(descriptor->ToString());
61      // TODO inspect result
62      return true;
63  }
64  
65  // If sign is true, transaction must previously have been filled
66  TransactionError ExternalSignerScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbt, const PrecomputedTransactionData& txdata, int sighash_type, bool sign, bool bip32derivs, int* n_signed, bool finalize) const
67  {
68      if (!sign) {
69          return DescriptorScriptPubKeyMan::FillPSBT(psbt, txdata, sighash_type, false, bip32derivs, n_signed, finalize);
70      }
71  
72      // Already complete if every input is now signed
73      bool complete = true;
74      for (const auto& input : psbt.inputs) {
75          // TODO: for multisig wallets, we should only care if all _our_ inputs are signed
76          complete &= PSBTInputSigned(input);
77      }
78      if (complete) return TransactionError::OK;
79  
80      std::string strFailReason;
81      if(!GetExternalSigner().SignTransaction(psbt, strFailReason)) {
82          tfm::format(std::cerr, "Failed to sign: %s\n", strFailReason);
83          return TransactionError::EXTERNAL_SIGNER_FAILED;
84      }
85      if (finalize) FinalizePSBT(psbt); // This won't work in a multisig setup
86      return TransactionError::OK;
87  }
88  } // namespace wallet