Merge #14477: Add ability to convert solvability info to descriptor

109699dd33 Add release notes (Pieter Wuille)
b65326b562 Add matching descriptors to scantxoutset output + tests (Pieter Wuille)
16203d5df7 Add descriptors to listunspent and getaddressinfo + tests (Pieter Wuille)
9b2a25b13f Add tests for InferDescriptor and Descriptor::IsSolvable (Pieter Wuille)
225bf3e3b0 Add Descriptor::IsSolvable() to distinguish addr/raw from others (Pieter Wuille)
4d78bd93b5 Add support for inferring descriptors from scripts (Pieter Wuille)

Pull request description:

  This PR adds functionality to convert a script to a descriptor, given a `SigningProvider` with the relevant information about public keys and redeemscripts/witnessscripts.

  The feature is exposed in `listunspent`, `getaddressinfo`, and `scantxoutset` whenever these calls are applied to solvable outputs/addresses.

  This is not very useful on its own, though when we add RPCs to import descriptors, or sign PSBTs using descriptors, these strings become a compact and standalone way of conveying everything necessary to sign an output (excluding private keys).

  Unit tests and rudimentary RPC tests are included (more relevant tests can be added once RPCs support descriptors).

  Fixes #14503.

Tree-SHA512: cb36b84a3e0200375b7e06a98c7e750cfaf95cf5de132cad59f7ec3cbd201f739427de0dc108f515be7aca203652089fbf5f24ed283d4553bddf23a3224ab31f

1 files changed, 13 insertions, 0 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index d4806b4c6b..b4c21631ab 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -22,6 +22,7 @@
 #include <rpc/rawtransaction.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
+#include <script/descriptor.h>
 #include <script/sign.h>
 #include <shutdown.h>
 #include <timedata.h>
@@ -2845,6 +2846,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
             "    \"redeemScript\" : n        (string) The redeemScript if scriptPubKey is P2SH\n"
             "    \"spendable\" : xxx,        (bool) Whether we have the private keys to spend this output\n"
             "    \"solvable\" : xxx,         (bool) Whether we know how to spend this output, ignoring the lack of keys\n"
+            "    \"desc\" : xxx,             (string, only when solvable) A descriptor for spending this output\n"
             "    \"safe\" : xxx              (bool) Whether this output is considered safe to spend. Unconfirmed transactions\n"
             "                              from outside keys and unconfirmed replacement transactions are considered unsafe\n"
             "                              and are not eligible for spending by fundrawtransaction and sendtoaddress.\n"
@@ -2963,6 +2965,10 @@ static UniValue listunspent(const JSONRPCRequest& request)
         entry.pushKV("confirmations", out.nDepth);
         entry.pushKV("spendable", out.fSpendable);
         entry.pushKV("solvable", out.fSolvable);
+        if (out.fSolvable) {
+            auto descriptor = InferDescriptor(scriptPubKey, *pwallet);
+            entry.pushKV("desc", descriptor->ToString());
+        }
         entry.pushKV("safe", out.fSafe);
         results.push_back(entry);
     }
@@ -3749,6 +3755,8 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
             "  \"ismine\" : true|false,        (boolean) If the address is yours or not\n"
             "  \"solvable\" : true|false,      (boolean) If the address is solvable by the wallet\n"
             "  \"iswatchonly\" : true|false,   (boolean) If the address is watchonly\n"
+            "  \"solvable\" : true|false,      (boolean) Whether we know how to spend coins sent to this address, ignoring the possible lack of private keys\n"
+            "  \"desc\" : \"desc\",            (string, optional) A descriptor for spending coins sent to this address (only when solvable)\n"
             "  \"isscript\" : true|false,      (boolean) If the key is a script\n"
             "  \"ischange\" : true|false,      (boolean) If the address was used for change output\n"
             "  \"iswitness\" : true|false,     (boolean) If the address is a witness address\n"
@@ -3802,6 +3810,11 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
 
     isminetype mine = IsMine(*pwallet, dest);
     ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
+    bool solvable = IsSolvable(*pwallet, scriptPubKey);
+    ret.pushKV("solvable", solvable);
+    if (solvable) {
+       ret.pushKV("desc", InferDescriptor(scriptPubKey, *pwallet)->ToString());
+    }
     ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
     ret.pushKV("solvable", IsSolvable(*pwallet, scriptPubKey));
     UniValue detail = DescribeWalletAddress(pwallet, dest);