Try #2229:

lib/core-integration/src/Test/Integration/Framework/DSL.hs

@@ -114,6 +114,7 @@ module Test.Integration.Framework.DSL
     , rootPrvKeyFromMnemonics
     , unsafeGetTransactionTime
     , getTxId
+    , getWalletKey
 
     -- * Delegation helpers
     , mkEpochInfo
@@ -174,6 +175,7 @@ import Cardano.Wallet.Api.Types
     , ApiTransaction
     , ApiTxId (ApiTxId)
     , ApiUtxoStatistics (..)
+    , ApiVerificationKeyHash
     , ApiWallet
     , ApiWalletDelegation (..)
     , ApiWalletDelegationNext (..)
@@ -212,6 +214,7 @@ import Cardano.Wallet.Primitive.Types
     ( ActiveSlotCoefficient (..)
     , Address (..)
     , Coin (..)
+    , DerivationIndex
     , EpochLength (..)
     , EpochNo
     , Hash (..)
@@ -1348,6 +1351,17 @@ listAddresses ctx w = do
     (_, addrs) <- unsafeRequest @[ApiAddress n] ctx link Empty
     return addrs
 
+getWalletKey
+    :: forall t w. ( HasType (ApiT WalletId) w )
+    => Context t
+    -> w
+    -> ApiT DerivationIndex
+    -> IO ApiVerificationKeyHash
+getWalletKey ctx w index = do
+    let link = Link.getWalletKey w index
+    (_, keyHash) <- unsafeRequest @ApiVerificationKeyHash ctx link Empty
+    return keyHash
+
 listAllTransactions
     :: forall n t w.
         ( DecodeAddress n

lib/core-integration/src/Test/Integration/Scenario/API/Shelley/Wallets.hs

@@ -28,6 +28,7 @@ import Cardano.Wallet.Api.Types
     , ApiT (..)
     , ApiTransaction
     , ApiUtxoStatistics
+    , ApiVerificationKeyHash
     , ApiWallet
     , DecodeAddress
     , DecodeStakeAddress
@@ -1118,6 +1119,24 @@ spec = describe "SHELLEY_WALLETS" $ do
             r <- request @ApiUtxoStatistics ctx (Link.getUTxOsStatistics @'Shelley w) headers Empty
             verify r expectations
 
+    describe "WALLETS_GET_KEY_01 - can get verification key hash for valid indices" $ do
+        let indices = fmap (ApiT . DerivationIndex) [ 0, 100, 2147483647 ]
+        forM_ indices $ \index -> it (show index) $ \ctx -> do
+
+            m <- genMnemonics M15
+            let payload = Json [json| {
+                    "name": "Wallet",
+                    "mnemonic_sentence": #{m},
+                    "passphrase": #{fixturePassphrase}
+                    } |]
+            r <- request @ApiWallet ctx (Link.postWallet @'Shelley) Default payload
+            verify r [ expectResponseCode @IO HTTP.status201 ]
+            let apiWal = getFromResponse id r
+
+            let link = Link.getWalletKey (apiWal ^. id) index
+            rGet <- request @ApiVerificationKeyHash ctx link Default Empty
+            verify rGet [ expectResponseCode @IO HTTP.status200 ]
+
     it "BYRON_WALLETS_UTXO -\
         \ Cannot show Byron wal utxo with shelley ep (404)" $ \ctx -> do
         w <- emptyRandomWallet ctx

lib/core/src/Cardano/Wallet/Api.hs

@@ -29,6 +29,9 @@ module Cardano.Wallet.Api
         , PutWalletPassphrase
         , GetUTxOsStatistics
 
+    , WalletKeys
+        , GetWalletKey
+
     , Addresses
         , ListAddresses
         , InspectAddress
@@ -128,6 +131,7 @@ import Cardano.Wallet.Api.Types
     , ApiTransactionT
     , ApiTxId
     , ApiUtxoStatistics
+    , ApiVerificationKeyHash
     , ApiWallet
     , ApiWalletMigrationInfo
     , ApiWalletMigrationPostDataT
@@ -156,6 +160,7 @@ import Cardano.Wallet.Primitive.Types
     ( AddressState
     , Block
     , Coin (..)
+    , DerivationIndex
     , NetworkParameters
     , SortOrder (..)
     , WalletId (..)
@@ -205,6 +210,7 @@ type ApiV2 n apiPool = "v2" :> Api n apiPool
 -- The API used in cardano-wallet-jormungandr may differ from this one.
 type Api n apiPool =
          Wallets
+    :<|> WalletKeys
     :<|> Addresses n
     :<|> CoinSelections n
     :<|> Transactions n
@@ -273,6 +279,22 @@ type GetUTxOsStatistics = "wallets"
     :> "utxos"
     :> Get '[JSON] ApiUtxoStatistics
 
+{-------------------------------------------------------------------------------
+                                  Wallet Keys
+  See also: https://input-output-hk.github.io/cardano-wallet/api/#tag/WalletKeys
+-------------------------------------------------------------------------------}
+
+type WalletKeys =
+    GetWalletKey
+
+-- | https://input-output-hk.github.io/cardano-wallet/api/#operation/getWalletKey
+type GetWalletKey = "wallets"
+    :> Capture "walletId" (ApiT WalletId)
+    :> "keys"
+    :> "script"
+    :> Capture "index" (ApiT DerivationIndex)
+    :> Get '[JSON] ApiVerificationKeyHash
+
 {-------------------------------------------------------------------------------
                                   Addresses
 

lib/core/src/Cardano/Wallet/Api/Link.hs

@@ -48,6 +48,9 @@ module Cardano.Wallet.Api.Link
     , getMigrationInfo
     , migrateWallet
 
+     -- * WalletKeys
+    , getWalletKey
+
       -- * Addresses
     , postRandomAddress
     , putRandomAddresses
@@ -104,7 +107,14 @@ import Cardano.Wallet.Api.Types
 import Cardano.Wallet.Primitive.AddressDerivation
     ( NetworkDiscriminant (..) )
 import Cardano.Wallet.Primitive.Types
-    ( AddressState, Coin (..), Hash, PoolId, SortOrder, WalletId (..) )
+    ( AddressState
+    , Coin (..)
+    , DerivationIndex
+    , Hash
+    , PoolId
+    , SortOrder
+    , WalletId (..)
+    )
 import Data.Function
     ( (&) )
 import Data.Generics.Internal.VL.Lens
@@ -255,6 +265,22 @@ getMigrationInfo w = discriminate @style
   where
     wid = w ^. typed @(ApiT WalletId)
 
+--
+-- WalletKeys
+--
+
+getWalletKey
+    :: forall w.
+        ( HasType (ApiT WalletId) w
+        )
+    => w
+    -> ApiT DerivationIndex
+    -> (Method, Text)
+getWalletKey w index =
+    endpoint @Api.GetWalletKey (\mk -> mk wid index)
+  where
+    wid = w ^. typed @(ApiT WalletId)
+
 --
 -- Addresses
 --

lib/core/src/Cardano/Wallet/Api/Server.hs

@@ -73,6 +73,7 @@ module Cardano.Wallet.Api.Server
     , putWalletPassphrase
     , quitStakePool
     , selectCoins
+    , getWalletKeyHash
 
     -- * Internals
     , LiftHandler(..)
@@ -95,8 +96,12 @@ import Prelude
 
 import Cardano.Address.Derivation
     ( XPrv, XPub )
+import Cardano.Address.Style.Shelley
+    ( deriveMultisigPublicKey, hashKey, liftXPub )
 import Cardano.Mnemonic
     ( SomeMnemonic )
+import Cardano.Script
+    ( KeyHash (..) )
 import Cardano.Wallet
     ( ErrAdjustForFee (..)
     , ErrCannotJoin (..)
@@ -185,6 +190,7 @@ import Cardano.Wallet.Api.Types
     , ApiTxInput (..)
     , ApiTxMetadata (..)
     , ApiUtxoStatistics (..)
+    , ApiVerificationKeyHash (..)
     , ApiWallet (..)
     , ApiWalletDelegation (..)
     , ApiWalletDelegationNext (..)
@@ -430,6 +436,7 @@ import qualified Cardano.Wallet.Api.Types as Api
 import qualified Cardano.Wallet.Network as NW
 import qualified Cardano.Wallet.Primitive.AddressDerivation.Byron as Byron
 import qualified Cardano.Wallet.Primitive.AddressDerivation.Icarus as Icarus
+import qualified Cardano.Wallet.Primitive.AddressDerivation.Shelley as Shelley
 import qualified Cardano.Wallet.Primitive.Slotting as S
 import qualified Cardano.Wallet.Primitive.Types as W
 import qualified Cardano.Wallet.Registry as Registry
@@ -1101,6 +1108,26 @@ getUTxOsStatistics ctx (ApiT wid) = do
         W.listUtxoStatistics wrk wid
     return $ toApiUtxoStatistics stats
 
+getWalletKeyHash
+    :: forall ctx s t k n.
+        ( s ~ SeqState n k
+        , ctx ~ ApiLayer s t k
+        , k ~ ShelleyKey
+        )
+    => ctx
+    -> ApiT WalletId
+    -> ApiT DerivationIndex
+    -> Handler ApiVerificationKeyHash
+getWalletKeyHash ctx (ApiT wid) (ApiT (DerivationIndex index)) =
+    withWorkerCtx @_ @s @k ctx wid liftE liftE $ \wrk -> do
+        (cp, _, _) <- liftHandler $ W.readWallet @_ @s @k wrk wid
+        let accPub = getState cp ^. #externalPool . #accountPubKey
+        let (KeyHash bytes) =
+                hashKey $ deriveMultisigPublicKey
+                (liftXPub $ Shelley.getKey accPub)
+                (toEnum $ fromInteger $ toInteger index)
+        pure $ ApiVerificationKeyHash $ ApiT $ Hash bytes
+
 {-------------------------------------------------------------------------------
                                   Coin Selections
 -------------------------------------------------------------------------------}

lib/core/src/Cardano/Wallet/Api/Types.hs

@@ -90,6 +90,7 @@ module Cardano.Wallet.Api.Types
     , ApiWalletMigrationPostData (..)
     , ApiWalletMigrationInfo (..)
     , ApiWithdrawal (..)
+    , ApiVerificationKeyHash (..)
 
     -- * API Types (Byron)
     , ApiByronWallet (..)
@@ -711,6 +712,10 @@ data ApiWalletMigrationInfo = ApiWalletMigrationInfo
 newtype ApiWithdrawRewards = ApiWithdrawRewards Bool
     deriving (Eq, Generic, Show)
 
+newtype ApiVerificationKeyHash = ApiVerificationKeyHash
+    { verificationKeyHash :: ApiT (Hash "ScriptKey")
+    } deriving (Eq, Generic, Show)
+
 -- | Error codes returned by the API, in the form of snake_cased strings
 data ApiErrorCode
     = NoSuchWallet
@@ -986,6 +991,17 @@ instance FromJSON (ApiT DerivationIndex) where
                 Just s ->
                     pure s
 
+instance FromJSON (ApiT (Hash "ScriptKey")) where
+    parseJSON =
+        parseJSON >=> eitherToParser . bimap ShowFmt ApiT . fromText
+instance ToJSON (ApiT (Hash "ScriptKey")) where
+    toJSON = toJSON . toText . getApiT
+
+instance ToJSON ApiVerificationKeyHash where
+    toJSON = genericToJSON defaultRecordTypeOptions
+instance FromJSON ApiVerificationKeyHash where
+    parseJSON = genericParseJSON defaultRecordTypeOptions
+
 instance FromJSON ApiEpochInfo where
     parseJSON = genericParseJSON defaultRecordTypeOptions
 instance ToJSON ApiEpochInfo where

lib/core/src/Cardano/Wallet/Primitive/Types.hs

@@ -1191,6 +1191,12 @@ newtype DerivationIndex
 
 instance NFData DerivationIndex
 
+instance FromText DerivationIndex where
+    fromText = fmap DerivationIndex . fromText
+
+instance ToText DerivationIndex where
+    toText (DerivationIndex index) = toText index
+
 {-------------------------------------------------------------------------------
                                      Coin
 -------------------------------------------------------------------------------}
@@ -1848,6 +1854,7 @@ instance FromText (Hash "Genesis")         where fromText = hashFromText 32
 instance FromText (Hash "Block")           where fromText = hashFromText 32
 instance FromText (Hash "BlockHeader")     where fromText = hashFromText 32
 instance FromText (Hash "ChimericAccount") where fromText = hashFromText 28
+instance FromText (Hash "ScriptKey")       where fromText = hashFromText 28
 
 hashFromText
     :: forall t. (KnownSymbol t)

lib/core/test/data/Cardano/Wallet/Api/ApiVerificationKeyHash.json

@@ -0,0 +1,35 @@
+{
+    "seed": 3843240765986310815,
+    "samples": [
+        {
+            "verification_key_hash": "f83d391427406d430e30534349563a7f58c9383c3b0a9d21091e6354"
+        },
+        {
+            "verification_key_hash": "2b5a99483598726a1975e3465a1a1bdf08516715254a7b4b784b1a22"
+        },
+        {
+            "verification_key_hash": "082d0f1d626904470724a7d8374f4bf20a0218500b057fb85b3b8445"
+        },
+        {
+            "verification_key_hash": "666b2a40060e37485c5633397e354a430b18126b4634335f5d3701cd"
+        },
+        {
+            "verification_key_hash": "3a612ab449126476577c656a92333f7d401021e2283a375abf49a627"
+        },
+        {
+            "verification_key_hash": "0669fc3c392c5e37474eb4031c8125101230f01260472720646b1b44"
+        },
+        {
+            "verification_key_hash": "7f2869354b6a66d10dd9685c04586e252f2c457856123d66896c680a"
+        },
+        {
+            "verification_key_hash": "625301105b51b91772532b55a202104f03251949720c6c7b0327530b"
+        },
+        {
+            "verification_key_hash": "9a6a1860033e420319030e59015d544b0669298d1203097710d34f2a"
+        },
+        {
+            "verification_key_hash": "308e7f5902082e041774b45c515d9801702276230b792a6b76314277"
+        }
+    ]
+}

lib/core/test/unit/Cardano/Wallet/Api/Malformed.hs

@@ -73,7 +73,7 @@ import Cardano.Wallet.Api.Types
 import Cardano.Wallet.Primitive.AddressDerivation
     ( NetworkDiscriminant (..) )
 import Cardano.Wallet.Primitive.Types
-    ( Address, WalletId, walletNameMaxLength )
+    ( Address, DerivationIndex, WalletId, walletNameMaxLength )
 import Control.Arrow
     ( first )
 import Data.Aeson.QQ
@@ -151,6 +151,22 @@ instance Malformed (PathParam ApiTxId) where
       where
         msg = "Invalid tx hash: expecting a hex-encoded value that is 32 bytes in length."
 
+instance Wellformed (PathParam (ApiT DerivationIndex)) where
+    wellformed = PathParam <$>
+        [ "0"
+        , "1000"
+        , "2147483647"
+        ]
+
+instance Malformed (PathParam (ApiT DerivationIndex)) where
+    malformed = first PathParam <$>
+        [ ("-1",msg)
+        , ("4.3",msg)
+        , ("something",msg)
+        ]
+      where
+        msg = "Expecting natural number"
+
 instance Wellformed (PathParam ApiPoolId) where
     wellformed = PathParam <$>
         [ T.replicate 64 "0"