2
0
mirror of https://github.com/lightninglabs/loop synced 2024-11-08 01:10:29 +00:00

Merge pull request #220 from wpaulino/walletkit-coin-selection

lndclient: expose basic coin selection RPCs for WalletKitClient
This commit is contained in:
Olaoluwa Osuntokun 2020-06-16 19:04:50 -07:00 committed by GitHub
commit 0d67b3987a
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 166 additions and 15 deletions

5
go.mod
View File

@ -4,6 +4,7 @@ require (
github.com/btcsuite/btcd v0.20.1-beta.0.20200515232429-9f0179fd2c46
github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f
github.com/btcsuite/btcutil v1.0.2
github.com/btcsuite/btcwallet/wtxmgr v1.1.1-0.20200604005347-6390f167e5f8
github.com/coreos/bbolt v1.3.3
github.com/fortytw2/leaktest v1.3.0
github.com/golang/protobuf v1.3.2
@ -11,9 +12,9 @@ require (
github.com/grpc-ecosystem/grpc-gateway v1.14.3
github.com/jessevdk/go-flags v1.4.0
github.com/lightninglabs/protobuf-hex-display v1.3.3-0.20191212020323-b444784ce75d
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200603030653-09bb9db78246
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200615174244-103c59a4889f
github.com/lightningnetwork/lnd/queue v1.0.4
github.com/stretchr/testify v1.4.0
github.com/stretchr/testify v1.5.1
github.com/urfave/cli v1.20.0
golang.org/x/net v0.0.0-20191002035440-2ec189313ef0
golang.org/x/text v0.3.2 // indirect

24
go.sum
View File

@ -30,8 +30,8 @@ github.com/btcsuite/btcutil v1.0.2 h1:9iZ1Terx9fMIOtq1VrwdqfsATL9MC2l8ZrUY6YZ2ut
github.com/btcsuite/btcutil v1.0.2/go.mod h1:j9HUFwoQRsZL3V4n+qG+CUnEGHOarIxfC3Le2Yhbcts=
github.com/btcsuite/btcutil/psbt v1.0.2 h1:gCVY3KxdoEVU7Q6TjusPO+GANIwVgr9yTLqM+a6CZr8=
github.com/btcsuite/btcutil/psbt v1.0.2/go.mod h1:LVveMu4VaNSkIRTZu2+ut0HDBRuYjqGocxDMNS1KuGQ=
github.com/btcsuite/btcwallet v0.11.1-0.20200515224913-e0e62245ecbe h1:0m9uXDcnUc3Fv72635O/MfLbhbW+0hfSVgRiWezpkHU=
github.com/btcsuite/btcwallet v0.11.1-0.20200515224913-e0e62245ecbe/go.mod h1:9+AH3V5mcTtNXTKe+fe63fDLKGOwQbZqmvOVUef+JFE=
github.com/btcsuite/btcwallet v0.11.1-0.20200604005347-6390f167e5f8 h1:wyooGuOeqcpJDK9+KgO5/yfb3nmEhakbdKHERhEylNE=
github.com/btcsuite/btcwallet v0.11.1-0.20200604005347-6390f167e5f8/go.mod h1:9+AH3V5mcTtNXTKe+fe63fDLKGOwQbZqmvOVUef+JFE=
github.com/btcsuite/btcwallet/wallet/txauthor v1.0.0 h1:KGHMW5sd7yDdDMkCZ/JpP0KltolFsQcB973brBnfj4c=
github.com/btcsuite/btcwallet/wallet/txauthor v1.0.0/go.mod h1:VufDts7bd/zs3GV13f/lXc/0lXrPnvxD/NvmpG/FEKU=
github.com/btcsuite/btcwallet/wallet/txrules v1.0.0 h1:2VsfS0sBedcM5KmDzRMT3+b6xobqWveZGvjb+jFez5w=
@ -43,8 +43,8 @@ github.com/btcsuite/btcwallet/walletdb v1.2.0/go.mod h1:9cwc1Yyg4uvd4ZdfdoMnALji
github.com/btcsuite/btcwallet/walletdb v1.3.1 h1:lW1Ac3F1jJY4K11P+YQtRNcP5jFk27ASfrV7C6mvRU0=
github.com/btcsuite/btcwallet/walletdb v1.3.1/go.mod h1:9cwc1Yyg4uvd4ZdfdoMnALji+V9gfWSMfxEdLdR5Vwc=
github.com/btcsuite/btcwallet/wtxmgr v1.0.0/go.mod h1:vc4gBprll6BP0UJ+AIGDaySoc7MdAmZf8kelfNb8CFY=
github.com/btcsuite/btcwallet/wtxmgr v1.1.1-0.20200515224913-e0e62245ecbe h1:yQbJVYfsKbdqDQNLxd4hhiLSiMkIygefW5mSHMsdKpc=
github.com/btcsuite/btcwallet/wtxmgr v1.1.1-0.20200515224913-e0e62245ecbe/go.mod h1:OwC0W0HhUszbWdvJvH6xvgabKSJ0lXl11YbmmqF9YXQ=
github.com/btcsuite/btcwallet/wtxmgr v1.1.1-0.20200604005347-6390f167e5f8 h1:tfeGHvGrm5nYE92eaO8PChBvMinpcq566dG1xPO08GI=
github.com/btcsuite/btcwallet/wtxmgr v1.1.1-0.20200604005347-6390f167e5f8/go.mod h1:cJGqxXtqQbmXuL7RlXjIM18x0bGHy1407/85mQCLca4=
github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd h1:R/opQEbFEy9JGkIguV40SvRY1uliPX8ifOvi6ICsFCw=
github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
github.com/btcsuite/golangcrypto v0.0.0-20150304025918-53f62d9b43e8/go.mod h1:tYvUd8KLhm/oXvUeSEs2VlLghFjQt9+ZaF9ghH0JNjc=
@ -123,7 +123,6 @@ github.com/grpc-ecosystem/go-grpc-middleware v1.0.0 h1:Iju5GlWwrvL6UBg4zJJt3btmo
github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 h1:Ovs26xHkKqVztRpIrF/92BcuyuQ/YW4NSIpoGtfXNho=
github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
github.com/grpc-ecosystem/grpc-gateway v1.8.6/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
github.com/grpc-ecosystem/grpc-gateway v1.14.3 h1:OCJlWkOUoTnl0neNGlf4fUm3TmbEtguw7vR+nGtnDjY=
github.com/grpc-ecosystem/grpc-gateway v1.14.3/go.mod h1:6CwZWGDSPRJidgKAtJVvND6soZe6fT7iteq8wDPdhb0=
github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
@ -176,11 +175,12 @@ github.com/lightninglabs/protobuf-hex-display v1.3.3-0.20191212020323-b444784ce7
github.com/lightninglabs/protobuf-hex-display v1.3.3-0.20191212020323-b444784ce75d/go.mod h1:KDb67YMzoh4eudnzClmvs2FbiLG9vxISmLApUkCa4uI=
github.com/lightningnetwork/lightning-onion v1.0.2-0.20200501022730-3c8c8d0b89ea h1:oCj48NQ8u7Vz+MmzHqt0db6mxcFZo3Ho7M5gCJauY/k=
github.com/lightningnetwork/lightning-onion v1.0.2-0.20200501022730-3c8c8d0b89ea/go.mod h1:rigfi6Af/KqsF7Za0hOgcyq2PNH4AN70AaMRxcJkff4=
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200603030653-09bb9db78246 h1:jQssf6KXK4cP4OkZj3Fi6wf88PXkFOeg/ZnF1joKjQM=
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200603030653-09bb9db78246/go.mod h1:CfulZMor9slr+ZrrbzGVTV4/AJ8SnQCnLNPEvk6Tzng=
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200615174244-103c59a4889f h1:/IS0Gy94ZZ0pJdwMmyb1B8RKszTY1aFm2+r/PItpbvs=
github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200615174244-103c59a4889f/go.mod h1:a2ejAHgjuwQ9YQJBzlMD8ZJHUcyWxXb8HRGe5QlJh9Y=
github.com/lightningnetwork/lnd/cert v1.0.2/go.mod h1:fmtemlSMf5t4hsQmcprSoOykypAPp+9c+0d0iqTScMo=
github.com/lightningnetwork/lnd/clock v1.0.0 h1:U9uknV7DwBsNUzc+x11tx1bPvoXiEYcJ9wrIemRibKE=
github.com/lightningnetwork/lnd/clock v1.0.0/go.mod h1:KnQudQ6w0IAMZi1SgvecLZQZ43ra2vpDNj7H/aasemg=
github.com/lightningnetwork/lnd/clock v1.0.1 h1:QQod8+m3KgqHdvVMV+2DRNNZS1GRFir8mHZYA+Z2hFo=
github.com/lightningnetwork/lnd/clock v1.0.1/go.mod h1:KnQudQ6w0IAMZi1SgvecLZQZ43ra2vpDNj7H/aasemg=
github.com/lightningnetwork/lnd/queue v1.0.1 h1:jzJKcTy3Nj5lQrooJ3aaw9Lau3I0IwvQR5sqtjdv2R0=
github.com/lightningnetwork/lnd/queue v1.0.1/go.mod h1:vaQwexir73flPW43Mrm7JOgJHmcEFBWWSl9HlyASoms=
github.com/lightningnetwork/lnd/queue v1.0.4 h1:8Dq3vxAFSACPy+pKN88oPFhuCpCoAAChPBwa4BJxH4k=
github.com/lightningnetwork/lnd/queue v1.0.4/go.mod h1:YTkTVZCxz8tAYreH27EO3s8572ODumWrNdYW2E/YKxg=
@ -226,7 +226,6 @@ github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R
github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084 h1:sofwID9zm4tzrgykg80hfFph1mryUeLRsUfoocVVmRY=
github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
github.com/rogpeppe/fastuuid v1.2.0 h1:Ppwyp6VYCF1nvBTXL3trRso7mXMlRrw9ooo375wvi2s=
github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
@ -242,6 +241,8 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5 h1:LnC5Kc/wtumK+WB441p7ynQJzVuNRJiqddSIE3IlSEQ=
github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
@ -285,7 +286,6 @@ golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73r
golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20181106065722-10aee1819953/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20190206173232-65e2d4e15006/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
@ -354,10 +354,8 @@ gopkg.in/macaroon.v2 v2.1.0 h1:HZcsjBCzq9t0eBPMKqTN/uSN6JOm78ZJ2INbqcBQOUI=
gopkg.in/macaroon.v2 v2.1.0/go.mod h1:OUb+TQP/OP0WOerC2Jp/3CwhIKyIa9kQjuc7H24e6/o=
gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22 h1:VpOs+IwYnYBaFnrNAeB8UUWtL3vEUnzSCL1nVjPhqrw=
gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22/go.mod h1:yeKp02qBN3iKW1OzL3MGk2IdtZzaj7SFntXj72NppTA=
gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.2.3 h1:fvjTMHxHEw/mxHbtzPi3JCcKXQRAnQTBRo6YCJSVHKI=

View File

@ -2,20 +2,46 @@ package lndclient
import (
"context"
"encoding/hex"
"fmt"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/btcsuite/btcwallet/wtxmgr"
"github.com/lightninglabs/loop/swap"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnrpc/signrpc"
"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/lnwallet/chainfee"
"google.golang.org/grpc"
)
// WalletKitClient exposes wallet functionality.
type WalletKitClient interface {
// ListUnspent returns a list of all utxos spendable by the wallet with
// a number of confirmations between the specified minimum and maximum.
ListUnspent(ctx context.Context, minConfs, maxConfs int32) (
[]*lnwallet.Utxo, error)
// LeaseOutput locks an output to the given ID, preventing it from being
// available for any future coin selection attempts. The absolute time
// of the lock's expiration is returned. The expiration of the lock can
// be extended by successive invocations of this call. Outputs can be
// unlocked before their expiration through `ReleaseOutput`.
LeaseOutput(ctx context.Context, lockID wtxmgr.LockID,
op wire.OutPoint) (time.Time, error)
// ReleaseOutput unlocks an output, allowing it to be available for coin
// selection if it remains unspent. The ID should match the one used to
// originally lock the output.
ReleaseOutput(ctx context.Context, lockID wtxmgr.LockID,
op wire.OutPoint) error
DeriveNextKey(ctx context.Context, family int32) (
*keychain.KeyDescriptor, error)
@ -38,6 +64,10 @@ type walletKitClient struct {
walletKitMac serializedMacaroon
}
// A compile-time constraint to ensure walletKitclient satisfies the
// WalletKitClient interface.
var _ WalletKitClient = (*walletKitClient)(nil)
func newWalletKitClient(conn *grpc.ClientConn,
walletKitMac serializedMacaroon) *walletKitClient {
@ -47,6 +77,107 @@ func newWalletKitClient(conn *grpc.ClientConn,
}
}
// ListUnspent returns a list of all utxos spendable by the wallet with a number
// of confirmations between the specified minimum and maximum.
func (m *walletKitClient) ListUnspent(ctx context.Context, minConfs,
maxConfs int32) ([]*lnwallet.Utxo, error) {
rpcCtx, cancel := context.WithTimeout(ctx, rpcTimeout)
defer cancel()
rpcCtx = m.walletKitMac.WithMacaroonAuth(rpcCtx)
resp, err := m.client.ListUnspent(rpcCtx, &walletrpc.ListUnspentRequest{
MinConfs: minConfs,
MaxConfs: maxConfs,
})
if err != nil {
return nil, err
}
utxos := make([]*lnwallet.Utxo, 0, len(resp.Utxos))
for _, utxo := range resp.Utxos {
var addrType lnwallet.AddressType
switch utxo.AddressType {
case lnrpc.AddressType_WITNESS_PUBKEY_HASH:
addrType = lnwallet.WitnessPubKey
case lnrpc.AddressType_NESTED_PUBKEY_HASH:
addrType = lnwallet.NestedWitnessPubKey
default:
return nil, fmt.Errorf("invalid utxo address type %v",
utxo.AddressType)
}
pkScript, err := hex.DecodeString(utxo.PkScript)
if err != nil {
return nil, err
}
opHash, err := chainhash.NewHash(utxo.Outpoint.TxidBytes)
if err != nil {
return nil, err
}
utxos = append(utxos, &lnwallet.Utxo{
AddressType: addrType,
Value: btcutil.Amount(utxo.AmountSat),
Confirmations: utxo.Confirmations,
PkScript: pkScript,
OutPoint: wire.OutPoint{
Hash: *opHash,
Index: utxo.Outpoint.OutputIndex,
},
})
}
return utxos, nil
}
// LeaseOutput locks an output to the given ID, preventing it from being
// available for any future coin selection attempts. The absolute time of the
// lock's expiration is returned. The expiration of the lock can be extended by
// successive invocations of this call. Outputs can be unlocked before their
// expiration through `ReleaseOutput`.
func (m *walletKitClient) LeaseOutput(ctx context.Context, lockID wtxmgr.LockID,
op wire.OutPoint) (time.Time, error) {
rpcCtx, cancel := context.WithTimeout(ctx, rpcTimeout)
defer cancel()
rpcCtx = m.walletKitMac.WithMacaroonAuth(rpcCtx)
resp, err := m.client.LeaseOutput(rpcCtx, &walletrpc.LeaseOutputRequest{
Id: lockID[:],
Outpoint: &lnrpc.OutPoint{
TxidBytes: op.Hash[:],
OutputIndex: op.Index,
},
})
if err != nil {
return time.Time{}, err
}
return time.Unix(int64(resp.Expiration), 0), nil
}
// ReleaseOutput unlocks an output, allowing it to be available for coin
// selection if it remains unspent. The ID should match the one used to
// originally lock the output.
func (m *walletKitClient) ReleaseOutput(ctx context.Context,
lockID wtxmgr.LockID, op wire.OutPoint) error {
rpcCtx, cancel := context.WithTimeout(ctx, rpcTimeout)
defer cancel()
rpcCtx = m.walletKitMac.WithMacaroonAuth(rpcCtx)
_, err := m.client.ReleaseOutput(rpcCtx, &walletrpc.ReleaseOutputRequest{
Id: lockID[:],
Outpoint: &lnrpc.OutPoint{
TxidBytes: op.Hash[:],
OutputIndex: op.Index,
},
})
return err
}
func (m *walletKitClient) DeriveNextKey(ctx context.Context, family int32) (
*keychain.KeyDescriptor, error) {

View File

@ -3,13 +3,16 @@ package test
import (
"context"
"errors"
"time"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/btcsuite/btcwallet/wtxmgr"
"github.com/lightninglabs/loop/lndclient"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/lnwallet/chainfee"
)
@ -21,6 +24,24 @@ type mockWalletKit struct {
var _ lndclient.WalletKitClient = (*mockWalletKit)(nil)
func (m *mockWalletKit) ListUnspent(ctx context.Context, minConfs,
maxConfs int32) ([]*lnwallet.Utxo, error) {
return nil, nil
}
func (m *mockWalletKit) LeaseOutput(ctx context.Context, lockID wtxmgr.LockID,
op wire.OutPoint) (time.Time, error) {
return time.Now(), nil
}
func (m *mockWalletKit) ReleaseOutput(ctx context.Context,
lockID wtxmgr.LockID, op wire.OutPoint) error {
return nil
}
func (m *mockWalletKit) DeriveNextKey(ctx context.Context, family int32) (
*keychain.KeyDescriptor, error) {