Introduce Credentials support (XLS-70d): (#5103)

Amendment:
    - Credentials
    
    New Transactions:
    - CredentialCreate
    - CredentialAccept
    - CredentialDelete
    
    Modified Transactions:
    - DepositPreauth
    - Payment
    - EscrowFinish
    - PaymentChannelClaim
    - AccountDelete
    
    New Object:
    - Credential

    Modified Object:
    - DepositPreauth
    
    API updates:
    - ledger_entry
    - account_objects
    - ledger_data
    - deposit_authorized
    
    Read full spec: https://github.com/XRPLF/XRPL-Standards/tree/master/XLS-0070d-credentials

include/xrpl/protocol/detail/features.macro

@@ -29,6 +29,8 @@
 // If you add an amendment here, then do not forget to increment `numFeatures`
 // in include/xrpl/protocol/Feature.h.
 
+XRPL_FEATURE(Credentials,                Supported::yes, VoteBehavior::DefaultNo)
+XRPL_FEATURE(AMMClawback,                Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (AMMv1_2,                    Supported::yes, VoteBehavior::DefaultNo)
 // InvariantsV1_1 will be changes to Supported::yes when all the
 // invariants expected to be included under it are complete.
@@ -96,7 +98,7 @@ XRPL_FIX    (1513,                       Supported::yes, VoteBehavior::DefaultYe
 XRPL_FEATURE(FlowCross,                  Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(Flow,                       Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(OwnerPaysFee,               Supported::no,  VoteBehavior::DefaultNo)
-XRPL_FEATURE(AMMClawback,                Supported::yes,  VoteBehavior::DefaultYes)
+
 
 // The following amendments are obsolete, but must remain supported
 // because they could potentially get enabled.

include/xrpl/protocol/detail/ledger_entries.macro

@@ -245,10 +245,11 @@ LEDGER_ENTRY(ltOFFER, 0x006f, Offer, ({
  */
 LEDGER_ENTRY(ltDEPOSIT_PREAUTH, 0x0070, DepositPreauth, ({
     {sfAccount,              soeREQUIRED},
-    {sfAuthorize,            soeREQUIRED},
+    {sfAuthorize,            soeOPTIONAL},
     {sfOwnerNode,            soeREQUIRED},
     {sfPreviousTxnID,        soeREQUIRED},
     {sfPreviousTxnLgrSeq,    soeREQUIRED},
+    {sfAuthorizeCredentials, soeOPTIONAL},
 }))
 
 /** A claim id for a cross chain transaction.
@@ -420,3 +421,18 @@ LEDGER_ENTRY(ltMPTOKEN, 0x007f, MPToken, ({
     {sfPreviousTxnID,            soeREQUIRED},
     {sfPreviousTxnLgrSeq,        soeREQUIRED},
 }))
+
+/** A ledger object which tracks Credential
+    \sa keylet::credential
+ */
+LEDGER_ENTRY(ltCREDENTIAL, 0x0081, Credential, ({
+    {sfSubject,              soeREQUIRED},
+    {sfIssuer,               soeREQUIRED},
+    {sfCredentialType,       soeREQUIRED},
+    {sfExpiration,           soeOPTIONAL},
+    {sfURI,                  soeOPTIONAL},
+    {sfIssuerNode,           soeREQUIRED},
+    {sfSubjectNode,          soeREQUIRED},
+    {sfPreviousTxnID,        soeREQUIRED},
+    {sfPreviousTxnLgrSeq,    soeREQUIRED},
+}))

include/xrpl/protocol/detail/sfields.macro

@@ -140,6 +140,8 @@ TYPED_SFIELD(sfAssetPrice,               UINT64,    23)
 TYPED_SFIELD(sfMaximumAmount,            UINT64,    24, SField::sMD_BaseTen|SField::sMD_Default)
 TYPED_SFIELD(sfOutstandingAmount,        UINT64,    25, SField::sMD_BaseTen|SField::sMD_Default)
 TYPED_SFIELD(sfMPTAmount,                UINT64,    26, SField::sMD_BaseTen|SField::sMD_Default)
+TYPED_SFIELD(sfIssuerNode,               UINT64,    27)
+TYPED_SFIELD(sfSubjectNode,              UINT64,    28)
 
 // 128-bit
 TYPED_SFIELD(sfEmailHash,                UINT128,    1)
@@ -258,6 +260,7 @@ TYPED_SFIELD(sfData,                     VL,        27)
 TYPED_SFIELD(sfAssetClass,               VL,        28)
 TYPED_SFIELD(sfProvider,                 VL,        29)
 TYPED_SFIELD(sfMPTokenMetadata,          VL,        30)
+TYPED_SFIELD(sfCredentialType,           VL,        31)
 
 // account (common)
 TYPED_SFIELD(sfAccount,                  ACCOUNT,    1)
@@ -280,12 +283,14 @@ TYPED_SFIELD(sfAttestationSignerAccount, ACCOUNT,   20)
 TYPED_SFIELD(sfAttestationRewardAccount, ACCOUNT,   21)
 TYPED_SFIELD(sfLockingChainDoor,         ACCOUNT,   22)
 TYPED_SFIELD(sfIssuingChainDoor,         ACCOUNT,   23)
+TYPED_SFIELD(sfSubject,                  ACCOUNT,   24)
 
 // vector of 256-bit
 TYPED_SFIELD(sfIndexes,                  VECTOR256,  1, SField::sMD_Never)
 TYPED_SFIELD(sfHashes,                   VECTOR256,  2)
 TYPED_SFIELD(sfAmendments,               VECTOR256,  3)
 TYPED_SFIELD(sfNFTokenOffers,            VECTOR256,  4)
+TYPED_SFIELD(sfCredentialIDs,            VECTOR256,  5)
 
 // path set
 UNTYPED_SFIELD(sfPaths,                  PATHSET,    1)
@@ -337,6 +342,7 @@ UNTYPED_SFIELD(sfXChainCreateAccountProofSig, OBJECT, 29)
 UNTYPED_SFIELD(sfXChainClaimAttestationCollectionElement, OBJECT, 30)
 UNTYPED_SFIELD(sfXChainCreateAccountAttestationCollectionElement, OBJECT, 31)
 UNTYPED_SFIELD(sfPriceData,              OBJECT,    32)
+UNTYPED_SFIELD(sfCredential,             OBJECT,    33)
 
 // array of objects (common)
 // ARRAY/1 is reserved for end of array
@@ -364,3 +370,5 @@ UNTYPED_SFIELD(sfXChainCreateAccountAttestations, ARRAY, 22)
 //                                                  23 unused
 UNTYPED_SFIELD(sfPriceDataSeries,        ARRAY,     24)
 UNTYPED_SFIELD(sfAuthAccounts,           ARRAY,     25)
+UNTYPED_SFIELD(sfAuthorizeCredentials,   ARRAY,     26)
+UNTYPED_SFIELD(sfUnauthorizeCredentials, ARRAY,     27)

include/xrpl/protocol/detail/transactions.macro

@@ -37,6 +37,7 @@ TRANSACTION(ttPAYMENT, 0, Payment, ({
     {sfInvoiceID, soeOPTIONAL},
     {sfDestinationTag, soeOPTIONAL},
     {sfDeliverMin, soeOPTIONAL, soeMPTSupported},
+    {sfCredentialIDs, soeOPTIONAL},
 }))
 
 /** This transaction type creates an escrow object. */
@@ -55,6 +56,7 @@ TRANSACTION(ttESCROW_FINISH, 2, EscrowFinish, ({
     {sfOfferSequence, soeREQUIRED},
     {sfFulfillment, soeOPTIONAL},
     {sfCondition, soeOPTIONAL},
+    {sfCredentialIDs, soeOPTIONAL},
 }))
 
 
@@ -139,6 +141,7 @@ TRANSACTION(ttPAYCHAN_CLAIM, 15, PaymentChannelClaim, ({
     {sfBalance, soeOPTIONAL},
     {sfSignature, soeOPTIONAL},
     {sfPublicKey, soeOPTIONAL},
+    {sfCredentialIDs, soeOPTIONAL},
 }))
 
 /** This transaction type creates a new check. */
@@ -166,6 +169,8 @@ TRANSACTION(ttCHECK_CANCEL, 18, CheckCancel, ({
 TRANSACTION(ttDEPOSIT_PREAUTH, 19, DepositPreauth, ({
     {sfAuthorize, soeOPTIONAL},
     {sfUnauthorize, soeOPTIONAL},
+    {sfAuthorizeCredentials, soeOPTIONAL},
+    {sfUnauthorizeCredentials, soeOPTIONAL},
 }))
 
 /** This transaction type modifies a trustline between two accounts. */
@@ -179,6 +184,7 @@ TRANSACTION(ttTRUST_SET, 20, TrustSet, ({
 TRANSACTION(ttACCOUNT_DELETE, 21, AccountDelete, ({
     {sfDestination, soeREQUIRED},
     {sfDestinationTag, soeOPTIONAL},
+    {sfCredentialIDs, soeOPTIONAL},
 }))
 
 // 22 reserved
@@ -420,6 +426,28 @@ TRANSACTION(ttMPTOKEN_AUTHORIZE, 57, MPTokenAuthorize, ({
     {sfHolder, soeOPTIONAL},
 }))
 
+/** This transaction type create an Credential instance */
+TRANSACTION(ttCREDENTIAL_CREATE, 58, CredentialCreate, ({
+    {sfSubject, soeREQUIRED},
+    {sfCredentialType, soeREQUIRED},
+    {sfExpiration, soeOPTIONAL},
+    {sfURI, soeOPTIONAL},
+}))
+
+/** This transaction type accept an Credential object */
+TRANSACTION(ttCREDENTIAL_ACCEPT, 59, CredentialAccept, ({
+    {sfIssuer, soeREQUIRED},
+    {sfCredentialType, soeREQUIRED},
+}))
+
+/** This transaction type delete an Credential object */
+TRANSACTION(ttCREDENTIAL_DELETE, 60, CredentialDelete, ({
+    {sfSubject, soeOPTIONAL},
+    {sfIssuer, soeOPTIONAL},
+    {sfCredentialType, soeREQUIRED},
+}))
+
+
 /** This system-generated transaction type is used to update the status of the various amendments.
 
     For details, see: https://xrpl.org/amendments.html
@@ -455,3 +483,4 @@ TRANSACTION(ttUNL_MODIFY, 102, UNLModify, ({
     {sfLedgerSequence, soeREQUIRED},
     {sfUNLModifyValidator, soeREQUIRED},
 }))
+