Add delegation tests for Confidential Transfers (#6729)

src/test/app/ConfidentialTransfer_test.cpp

@@ -7311,6 +7311,325 @@ class ConfidentialTransfer_test : public beast::unit_test::suite
         mptAlice.mergeInbox({.account = bob, .ticketSeq = 1, .err = tefNO_TICKET});
     }
 
+    // Basic tests of confidential transfer through delegation. Verifies that a delegated account
+    // with the appropriate permissions can execute confidential transfer transactions
+    // on behalf of the delegator.
+    void
+    testConfidentialDelegation(FeatureBitset features)
+    {
+        testcase("Confidential transfers through delegation");
+        using namespace test::jtx;
+
+        Env env{*this, features};
+        Account const alice{"alice"};
+        Account const bob{"bob"};
+        Account const carol{"carol"};
+        Account const dave{"dave"};
+
+        MPTTester mptAlice(env, alice, {.holders = {bob, carol}});
+        env.fund(XRP(10000), dave);
+        env.close();
+
+        mptAlice.create({
+            .ownerCount = 1,
+            .flags =
+                tfMPTCanTransfer | tfMPTCanLock | tfMPTCanClawback | tfMPTCanConfidentialAmount,
+        });
+        mptAlice.authorize({.account = bob});
+        mptAlice.authorize({.account = carol});
+        mptAlice.pay(alice, bob, 200);
+        mptAlice.pay(alice, carol, 100);
+
+        mptAlice.generateKeyPair(alice);
+        mptAlice.generateKeyPair(bob);
+        mptAlice.generateKeyPair(carol);
+        mptAlice.set({.issuerPubKey = mptAlice.getPubKey(alice)});
+
+        // Bob delegates Convert, MergeInbox to dave.
+        env(delegate::set(bob, dave, {"ConfidentialMPTConvert", "ConfidentialMPTMergeInbox"}));
+        env.close();
+
+        // Carol has no permission from bob to convert on his behalf.
+        mptAlice.convert({
+            .account = bob,
+            .amt = 10,
+            .holderPubKey = mptAlice.getPubKey(bob),
+            .delegate = carol,
+            .err = terNO_DELEGATE_PERMISSION,
+        });
+
+        // Dave executes Convert on behalf of bob, registering bob's key.
+        mptAlice.convert({
+            .account = bob,
+            .amt = 100,
+            .holderPubKey = mptAlice.getPubKey(bob),
+            .delegate = dave,
+        });
+        env.require(mptbalance(mptAlice, bob, 100));
+
+        // Dave executes Convert again on behalf of bob (no key registration).
+        mptAlice.convert({.account = bob, .amt = 50, .delegate = dave});
+
+        // Dave executes MergeInbox on behalf of bob.
+        mptAlice.mergeInbox({.account = bob, .delegate = dave});
+
+        // Carol converts and merge inbox.
+        mptAlice.convert({
+            .account = carol,
+            .amt = 100,
+            .holderPubKey = mptAlice.getPubKey(carol),
+        });
+        mptAlice.mergeInbox({.account = carol});
+
+        // Dave does not have permission to send on behalf of bob.
+        mptAlice.send(
+            {.account = bob,
+             .dest = carol,
+             .amt = 10,
+             .delegate = dave,
+             .err = terNO_DELEGATE_PERMISSION});
+
+        // Bob delegates ConfidentialMPTSend to dave.
+        env(delegate::set(
+            bob,
+            dave,
+            {"ConfidentialMPTConvert", "ConfidentialMPTMergeInbox", "ConfidentialMPTSend"}));
+        env.close();
+
+        // Dave executes Send on behalf of bob.
+        mptAlice.send({.account = bob, .dest = carol, .amt = 10, .delegate = dave});
+        mptAlice.mergeInbox({.account = carol});
+
+        // Dave does not have permission to convert back on behalf of bob.
+        mptAlice.convertBack(
+            {.account = bob, .amt = 10, .delegate = dave, .err = terNO_DELEGATE_PERMISSION});
+
+        // Bob delegates ConfidentialMPTConvertBack to dave.
+        env(delegate::set(
+            bob,
+            dave,
+            {"ConfidentialMPTConvert",
+             "ConfidentialMPTMergeInbox",
+             "ConfidentialMPTSend",
+             "ConfidentialMPTConvertBack"}));
+        env.close();
+
+        // Dave executes ConvertBack on behalf of bob.
+        mptAlice.convertBack({.account = bob, .amt = 10, .delegate = dave});
+
+        // Dave does not have permission to clawback on behalf of alice.
+        mptAlice.confidentialClaw(
+            {.holder = bob, .amt = 130, .delegate = dave, .err = terNO_DELEGATE_PERMISSION});
+
+        // Alice delegates ConfidentialMPTClawback to dave.
+        env(delegate::set(alice, dave, {"ConfidentialMPTClawback"}));
+        env.close();
+
+        // Dave executes Clawback on behalf of alice.
+        mptAlice.confidentialClaw({.holder = bob, .amt = 130, .delegate = dave});
+    }
+
+    // Verifies that revoking delegation prevents further delegated operations.
+    void
+    testDelegationRevocation(FeatureBitset features)
+    {
+        testcase("Confidential delegation revocation");
+        using namespace test::jtx;
+
+        Env env{*this, features};
+        Account const alice{"alice"};
+        Account const bob{"bob"};
+        Account const carol{"carol"};
+
+        MPTTester mptAlice(env, alice, {.holders = {bob}});
+        env.fund(XRP(10000), carol);
+        env.close();
+
+        mptAlice.create({
+            .ownerCount = 1,
+            .flags = tfMPTCanTransfer | tfMPTCanConfidentialAmount,
+        });
+        mptAlice.authorize({.account = bob});
+        mptAlice.pay(alice, bob, 100);
+
+        mptAlice.generateKeyPair(alice);
+        mptAlice.generateKeyPair(bob);
+        mptAlice.set({.issuerPubKey = mptAlice.getPubKey(alice)});
+
+        // Creating the Delegate SLE consumes one owner reserve slot for bob.
+        auto const bobOwnersBefore = ownerCount(env, bob);
+        env(delegate::set(bob, carol, {"ConfidentialMPTConvert", "ConfidentialMPTMergeInbox"}));
+        env.close();
+        env.require(owners(bob, bobOwnersBefore + 1));
+
+        // Carol converts and merge inbox on behalf of bob.
+        mptAlice.convert({
+            .account = bob,
+            .amt = 50,
+            .holderPubKey = mptAlice.getPubKey(bob),
+            .delegate = carol,
+        });
+        mptAlice.mergeInbox({.account = bob, .delegate = carol});
+
+        // Bob revokes all permissions, deletes the Delegate SLE, releasing the reserve.
+        env(delegate::set(bob, carol, std::vector<std::string>{}));
+        env.close();
+        env.require(owners(bob, bobOwnersBefore));
+
+        // Carol can no longer convert on behalf of bob.
+        mptAlice.convert({
+            .account = bob,
+            .amt = 30,
+            .delegate = carol,
+            .err = terNO_DELEGATE_PERMISSION,
+        });
+
+        // Bob can still convert by himself.
+        mptAlice.convert({.account = bob, .amt = 30});
+    }
+
+    // Verifies that a delegated confidential transfer works correctly when an
+    // auditor is configured on the issuance.
+    void
+    testDelegationWithAuditor(FeatureBitset features)
+    {
+        testcase("Confidential delegation with auditor");
+        using namespace test::jtx;
+
+        Env env{*this, features};
+        Account const alice{"alice"};
+        Account const bob{"bob"};
+        Account const carol{"carol"};
+        Account const dave{"dave"};
+        Account const auditor{"auditor"};
+
+        MPTTester mptAlice(env, alice, {.holders = {bob, carol}, .auditor = auditor});
+        env.fund(XRP(10000), dave);
+        env.close();
+
+        mptAlice.create({
+            .ownerCount = 1,
+            .flags = tfMPTCanTransfer | tfMPTCanConfidentialAmount,
+        });
+        mptAlice.authorize({.account = bob});
+        mptAlice.authorize({.account = carol});
+        mptAlice.pay(alice, bob, 100);
+        mptAlice.pay(alice, carol, 100);
+
+        mptAlice.generateKeyPair(alice);
+        mptAlice.generateKeyPair(bob);
+        mptAlice.generateKeyPair(carol);
+        mptAlice.generateKeyPair(auditor);
+        mptAlice.set(
+            {.issuerPubKey = mptAlice.getPubKey(alice),
+             .auditorPubKey = mptAlice.getPubKey(auditor)});
+
+        // Bob delegates Convert and Send permissions to dave.
+        env(delegate::set(bob, dave, {"ConfidentialMPTSend", "ConfidentialMPTConvert"}));
+        env.close();
+
+        // Dave converts on behalf of bob.
+        mptAlice.convert(
+            {.account = bob, .amt = 50, .holderPubKey = mptAlice.getPubKey(bob), .delegate = dave});
+        mptAlice.mergeInbox({.account = bob});
+
+        mptAlice.convert({
+            .account = carol,
+            .amt = 50,
+            .holderPubKey = mptAlice.getPubKey(carol),
+        });
+        mptAlice.mergeInbox({.account = carol});
+
+        // Dave sends on behalf of bob.
+        mptAlice.send({.account = bob, .dest = carol, .amt = 20, .delegate = dave});
+        mptAlice.send({.account = bob, .dest = carol, .amt = 10, .delegate = dave});
+
+        // Bob delegates ConvertBack and Send permissions to auditor.
+        env(delegate::set(bob, auditor, {"ConfidentialMPTSend", "ConfidentialMPTConvertBack"}));
+        env.close();
+
+        // auditor can send and convert back on behalf of bob as well.
+        mptAlice.send({.account = bob, .dest = carol, .amt = 10, .delegate = auditor});
+        mptAlice.convertBack({.account = bob, .amt = 10, .delegate = auditor});
+    }
+
+    // Verifies that a non-issuer delegating clawback to a third party does not
+    // allow that party to execute clawback, since clawback is issuer-only.
+    void
+    testDelegationClawbackIssuerOnly(FeatureBitset features)
+    {
+        testcase("Confidential clawback delegation requires issuer");
+        using namespace test::jtx;
+
+        Env env{*this, features};
+        Account const alice{"alice"};
+        Account const bob{"bob"};
+        Account const carol{"carol"};
+        Account const dave{"dave"};
+
+        MPTTester mptAlice(env, alice, {.holders = {bob, carol}});
+        env.fund(XRP(10000), dave);
+        env.close();
+
+        mptAlice.create({
+            .ownerCount = 1,
+            .flags = tfMPTCanTransfer | tfMPTCanClawback | tfMPTCanConfidentialAmount,
+        });
+        mptAlice.authorize({.account = bob});
+        mptAlice.authorize({.account = carol});
+        mptAlice.pay(alice, bob, 100);
+        mptAlice.pay(alice, carol, 100);
+
+        mptAlice.generateKeyPair(alice);
+        mptAlice.generateKeyPair(bob);
+        mptAlice.generateKeyPair(carol);
+        mptAlice.set({.issuerPubKey = mptAlice.getPubKey(alice)});
+
+        mptAlice.convert({
+            .account = bob,
+            .amt = 50,
+            .holderPubKey = mptAlice.getPubKey(bob),
+        });
+        mptAlice.mergeInbox({.account = bob});
+
+        mptAlice.convert({
+            .account = carol,
+            .amt = 100,
+            .holderPubKey = mptAlice.getPubKey(carol),
+        });
+        mptAlice.mergeInbox({.account = carol});
+
+        // Bob delegates Clawback permission to dave.
+        env(delegate::set(bob, dave, {"ConfidentialMPTClawback"}));
+        env.close();
+
+        // Dave attempts clawback on behalf of bob targetting bob, but since bob is not the issuer,
+        // the transaction should be rejected.
+        {
+            Json::Value jv;
+            jv[jss::Account] = bob.human();
+            jv[jss::TransactionType] = jss::ConfidentialMPTClawback;
+            jv[sfMPTokenIssuanceID] = to_string(mptAlice.issuanceID());
+            jv[sfHolder] = bob.human();
+            jv[sfMPTAmount.jsonName] = "50";
+            jv[sfZKProof.jsonName] = std::string(ecEqualityProofLength * 2, '0');
+            env(jv, delegate::as(dave), ter(temMALFORMED));
+        }
+
+        // Dave attempts clawback on behalf of bob targeting carol, but since bob is not the issuer,
+        // the transaction should be rejected.
+        {
+            Json::Value jv;
+            jv[jss::Account] = bob.human();
+            jv[jss::TransactionType] = jss::ConfidentialMPTClawback;
+            jv[sfMPTokenIssuanceID] = to_string(mptAlice.issuanceID());
+            jv[sfHolder] = carol.human();
+            jv[sfMPTAmount.jsonName] = "100";
+            jv[sfZKProof.jsonName] = std::string(ecEqualityProofLength * 2, '0');
+            env(jv, delegate::as(dave), ter(temMALFORMED));
+        }
+    }
+
     void
     testWithFeats(FeatureBitset features)
     {
@@ -7377,6 +7696,12 @@ class ConfidentialTransfer_test : public beast::unit_test::suite
         testWithTickets(features);
         testConvertTicketProofBinding(features);
         testTicketErrors(features);
+
+        // Delegation Tests
+        testConfidentialDelegation(features);
+        testDelegationRevocation(features);
+        testDelegationWithAuditor(features);
+        testDelegationClawbackIssuerOnly(features);
     }
 
 public:

src/test/jtx/mpt.h

@@ -200,6 +200,7 @@ struct MPTConvert
     std::optional<Buffer> auditorEncryptedAmt = std::nullopt;
 
     std::optional<Buffer> blindingFactor = std::nullopt;
+    std::optional<Account> delegate = std::nullopt;
     std::optional<std::uint32_t> ticketSeq = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
@@ -211,6 +212,7 @@ struct MPTMergeInbox
 {
     std::optional<Account> account = std::nullopt;
     std::optional<MPTID> id = std::nullopt;
+    std::optional<Account> delegate = std::nullopt;
     std::optional<std::uint32_t> ticketSeq = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
@@ -235,6 +237,7 @@ struct MPTConfidentialSend
     std::optional<Buffer> blindingFactor = std::nullopt;
     std::optional<Buffer> amountCommitment = std::nullopt;
     std::optional<Buffer> balanceCommitment = std::nullopt;
+    std::optional<Account> delegate = std::nullopt;
     std::optional<std::uint32_t> ticketSeq = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
@@ -255,6 +258,7 @@ struct MPTConvertBack
     // not an txn param, only used for autofilling
     std::optional<Buffer> blindingFactor = std::nullopt;
     std::optional<Buffer> pedersenCommitment = std::nullopt;
+    std::optional<Account> delegate = std::nullopt;
     std::optional<std::uint32_t> ticketSeq = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
@@ -269,6 +273,7 @@ struct MPTConfidentialClawback
     std::optional<MPTID> id = std::nullopt;
     std::optional<std::uint64_t> amt = std::nullopt;
     std::optional<std::string> proof = std::nullopt;
+    std::optional<Account> delegate = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
     std::optional<std::uint32_t> flags = std::nullopt;
@@ -530,17 +535,28 @@ private:
     {
         auto const expectedFlags = txflags(arg.flags.value_or(0));
         auto const expectedTer = ter(arg.err.value_or(tesSUCCESS));
+
+        std::optional<std::uint32_t> ticketSeq;
         if constexpr (requires { arg.ticketSeq; })
-        {
-            if (arg.ticketSeq)
-                env_(jv, expectedFlags, expectedTer, ticket::use(*arg.ticketSeq));
-            else
-                env_(jv, expectedFlags, expectedTer);
-        }
+            ticketSeq = arg.ticketSeq;
+
+        std::optional<Account> delegateAcct;
+        if constexpr (requires { arg.delegate; })
+            delegateAcct = arg.delegate;
+
+        if (ticketSeq && delegateAcct)
+            env_(
+                jv,
+                expectedFlags,
+                expectedTer,
+                ticket::use(*ticketSeq),
+                delegate::as(*delegateAcct));
+        else if (ticketSeq)
+            env_(jv, expectedFlags, expectedTer, ticket::use(*ticketSeq));
+        else if (delegateAcct)
+            env_(jv, expectedFlags, expectedTer, delegate::as(*delegateAcct));
         else
-        {
             env_(jv, expectedFlags, expectedTer);
-        }
         auto const err = env_.ter();
         if (close_)
             env_.close();