12199391122

Committed 06 Dec 2024 01:10PM UTC coverage: 49.807% (-9.1%) from 58.933%

Build # 12199391122

Build Type

push

github

Committed by

web-flow

Commit Message

Merge pull request #9337 from Guayaba221/patch-1

chore: fix typo in ruby.md

Run Details

100137 of 201051 relevant lines covered (49.81%)

2.07 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

76.21

/lnwallet/btcwallet/signer.go

package btcwallet

import (
        "fmt"

        "github.com/btcsuite/btcd/btcec/v2"
        "github.com/btcsuite/btcd/btcec/v2/ecdsa"
        "github.com/btcsuite/btcd/btcec/v2/schnorr"
        "github.com/btcsuite/btcd/btcutil"
        "github.com/btcsuite/btcd/btcutil/hdkeychain"
        "github.com/btcsuite/btcd/btcutil/psbt"
        "github.com/btcsuite/btcd/chaincfg/chainhash"
        "github.com/btcsuite/btcd/txscript"
        "github.com/btcsuite/btcd/wire"
        "github.com/btcsuite/btcwallet/waddrmgr"
        "github.com/btcsuite/btcwallet/walletdb"
        "github.com/lightningnetwork/lnd/input"
        "github.com/lightningnetwork/lnd/keychain"
        "github.com/lightningnetwork/lnd/lnwallet"
)

// FetchOutpointInfo queries for the WalletController's knowledge of the passed
// outpoint. If the base wallet determines this output is under its control,
// then the original txout should be returned. Otherwise, a non-nil error value
// of ErrNotMine should be returned instead.
//
// This is a part of the WalletController interface.
func (b *BtcWallet) FetchOutpointInfo(prevOut *wire.OutPoint) (*lnwallet.Utxo,
        error) {

        prevTx, txOut, confirmations, err := b.wallet.FetchOutpointInfo(prevOut)
        if err != nil {
                return nil, err
        }

        // Then, we'll populate all of the information required by the struct.
        addressType := lnwallet.UnknownAddressType
        switch {
        case txscript.IsPayToWitnessPubKeyHash(txOut.PkScript):
                addressType = lnwallet.WitnessPubKey
        case txscript.IsPayToScriptHash(txOut.PkScript):
                addressType = lnwallet.NestedWitnessPubKey
        case txscript.IsPayToTaproot(txOut.PkScript):
                addressType = lnwallet.TaprootPubkey
        }

        return &lnwallet.Utxo{
                AddressType:   addressType,
                Value:         btcutil.Amount(txOut.Value),
                PkScript:      txOut.PkScript,
                Confirmations: confirmations,
                OutPoint:      *prevOut,
                PrevTx:        prevTx,
        }, nil
}

// FetchDerivationInfo queries for the wallet's knowledge of the passed
// pkScript and constructs the derivation info and returns it.
func (b *BtcWallet) FetchDerivationInfo(
        pkScript []byte) (*psbt.Bip32Derivation, error) {

        return b.wallet.FetchDerivationInfo(pkScript)
}

// ScriptForOutput returns the address, witness program and redeem script for a
// given UTXO. An error is returned if the UTXO does not belong to our wallet or
// it is not a managed pubKey address.
func (b *BtcWallet) ScriptForOutput(output *wire.TxOut) (
        waddrmgr.ManagedPubKeyAddress, []byte, []byte, error) {

        return b.wallet.ScriptForOutput(output)
}

// deriveFromKeyLoc attempts to derive a private key using a fully specified
// KeyLocator.
func deriveFromKeyLoc(scopedMgr *waddrmgr.ScopedKeyManager,
        addrmgrNs walletdb.ReadWriteBucket,
        keyLoc keychain.KeyLocator) (*btcec.PrivateKey, error) {

        path := waddrmgr.DerivationPath{
                InternalAccount: uint32(keyLoc.Family),
                Account:         uint32(keyLoc.Family),
                Branch:          0,
                Index:           keyLoc.Index,
        }
        addr, err := scopedMgr.DeriveFromKeyPath(addrmgrNs, path)
        if err != nil {
                return nil, err
        }

        return addr.(waddrmgr.ManagedPubKeyAddress).PrivKey()
}

// deriveKeyByBIP32Path derives a key described by a BIP32 path. We expect the
// first three elements of the path to be hardened according to BIP44, so they
// must be a number >= 2^31.
func (b *BtcWallet) deriveKeyByBIP32Path(path []uint32) (*btcec.PrivateKey,
        error) {

        // Make sure we get a full path with exactly 5 elements. A path is
        // either custom purpose one with 4 dynamic and one static elements:
        //    m/1017'/coinType'/keyFamily'/0/index
        // Or a default BIP49/89 one with 5 elements:
        //    m/purpose'/coinType'/account'/change/index
        const expectedDerivationPathDepth = 5
        if len(path) != expectedDerivationPathDepth {
                return nil, fmt.Errorf("invalid BIP32 derivation path, "+
                        "expected path length %d, instead was %d",
                        expectedDerivationPathDepth, len(path))
        }

        // Assert that the first three parts of the path are actually hardened
        // to avoid under-flowing the uint32 type.
        if err := assertHardened(path[0], path[1], path[2]); err != nil {
                return nil, fmt.Errorf("invalid BIP32 derivation path, "+
                        "expected first three elements to be hardened: %w", err)
        }

        purpose := path[0] - hdkeychain.HardenedKeyStart
        coinType := path[1] - hdkeychain.HardenedKeyStart
        account := path[2] - hdkeychain.HardenedKeyStart
        change, index := path[3], path[4]

        // Is this a custom lnd internal purpose key?
        switch purpose {
        case keychain.BIP0043Purpose:
                // Make sure it's for the same coin type as our wallet's
                // keychain scope.
                if coinType != b.chainKeyScope.Coin {
                        return nil, fmt.Errorf("invalid BIP32 derivation "+
                                "path, expected coin type %d, instead was %d",
                                b.chainKeyScope.Coin, coinType)
                }

                return b.deriveKeyByLocator(keychain.KeyLocator{
                        Family: keychain.KeyFamily(account),
                        Index:  index,
                })

        // Is it a standard, BIP defined purpose that the wallet understands?
        case waddrmgr.KeyScopeBIP0044.Purpose,
                waddrmgr.KeyScopeBIP0049Plus.Purpose,
                waddrmgr.KeyScopeBIP0084.Purpose,
                waddrmgr.KeyScopeBIP0086.Purpose:

                // We're going to continue below the switch statement to avoid
                // unnecessary indentation for this default case.

        // Currently, there is no way to import any other key scopes than the
        // one custom purpose or three standard ones into lnd's wallet. So we
        // shouldn't accept any other scopes to sign for.
        default:
                return nil, fmt.Errorf("invalid BIP32 derivation path, "+
                        "unknown purpose %d", purpose)
        }

        // Okay, we made sure it's a BIP49/84 key, so we need to derive it now.
        // Interestingly, the btcwallet never actually uses a coin type other
        // than 0 for those keys, so we need to make sure this behavior is
        // replicated here.
        if coinType != 0 {
                return nil, fmt.Errorf("invalid BIP32 derivation path, coin " +
                        "type must be 0 for BIP49/84 btcwallet keys")
        }

        // We only expect to be asked to sign with key scopes that we know
        // about. So if the scope doesn't exist, we don't create it.
        scope := waddrmgr.KeyScope{
                Purpose: purpose,
                Coin:    coinType,
        }
        scopedMgr, err := b.wallet.Manager.FetchScopedKeyManager(scope)
        if err != nil {
                return nil, fmt.Errorf("error fetching manager for scope %v: "+
                        "%w", scope, err)
        }

        // Let's see if we can hit the private key cache.
        keyPath := waddrmgr.DerivationPath{
                InternalAccount: account,
                Account:         account,
                Branch:          change,
                Index:           index,
        }
        privKey, err := scopedMgr.DeriveFromKeyPathCache(keyPath)
        if err == nil {
                return privKey, nil
        }

        // The key wasn't in the cache, let's fully derive it now.
        err = walletdb.View(b.db, func(tx walletdb.ReadTx) error {
                addrmgrNs := tx.ReadBucket(waddrmgrNamespaceKey)

                addr, err := scopedMgr.DeriveFromKeyPath(addrmgrNs, keyPath)
                if err != nil {
                        return fmt.Errorf("error deriving private key: %w", err)
                }

                privKey, err = addr.(waddrmgr.ManagedPubKeyAddress).PrivKey()
                return err
        })
        if err != nil {
                return nil, fmt.Errorf("error deriving key from path %#v: %w",
                        keyPath, err)
        }

        return privKey, nil
}

// assertHardened makes sure each given element is >= 2^31.
func assertHardened(elements ...uint32) error {
        for idx, element := range elements {
                if element < hdkeychain.HardenedKeyStart {
                        return fmt.Errorf("element at index %d is not hardened",
                                idx)
                }
        }

        return nil
}

// deriveKeyByLocator attempts to derive a key stored in the wallet given a
// valid key locator.
func (b *BtcWallet) deriveKeyByLocator(
        keyLoc keychain.KeyLocator) (*btcec.PrivateKey, error) {

        // We'll assume the special lightning key scope in this case.
        scopedMgr, err := b.wallet.Manager.FetchScopedKeyManager(
                b.chainKeyScope,
        )
        if err != nil {
                return nil, err
        }

        // First try to read the key from the cached store, if this fails, then
        // we'll fall through to the method below that requires a database
        // transaction.
        path := waddrmgr.DerivationPath{
                InternalAccount: uint32(keyLoc.Family),
                Account:         uint32(keyLoc.Family),
                Branch:          0,
                Index:           keyLoc.Index,
        }
        privKey, err := scopedMgr.DeriveFromKeyPathCache(path)
        if err == nil {
                return privKey, nil
        }

        var key *btcec.PrivateKey
        err = walletdb.Update(b.db, func(tx walletdb.ReadWriteTx) error {
                addrmgrNs := tx.ReadWriteBucket(waddrmgrNamespaceKey)

                key, err = deriveFromKeyLoc(scopedMgr, addrmgrNs, keyLoc)
                if waddrmgr.IsError(err, waddrmgr.ErrAccountNotFound) {
                        // If we've reached this point, then the account
                        // doesn't yet exist, so we'll create it now to ensure
                        // we can sign.
                        acctErr := scopedMgr.NewRawAccount(
                                addrmgrNs, uint32(keyLoc.Family),
                        )
                        if acctErr != nil {
                                return acctErr
                        }

                        // Now that we know the account exists, we'll attempt
                        // to re-derive the private key.
                        key, err = deriveFromKeyLoc(
                                scopedMgr, addrmgrNs, keyLoc,
                        )
                        if err != nil {
                                return err
                        }
                }

                return err
        })
        if err != nil {
                return nil, err
        }

        return key, nil
}

// fetchPrivKey attempts to retrieve the raw private key corresponding to the
// passed public key if populated, or the key descriptor path (if non-empty).
func (b *BtcWallet) fetchPrivKey(
        keyDesc *keychain.KeyDescriptor) (*btcec.PrivateKey, error) {

        // If the key locator within the descriptor *isn't* empty, then we can
        // directly derive the keys raw.
        emptyLocator := keyDesc.KeyLocator.IsEmpty()
        if !emptyLocator || keyDesc.PubKey == nil {
                return b.deriveKeyByLocator(keyDesc.KeyLocator)
        }

        hash160 := btcutil.Hash160(keyDesc.PubKey.SerializeCompressed())
        addr, err := btcutil.NewAddressWitnessPubKeyHash(hash160, b.netParams)
        if err != nil {
                return nil, err
        }

        // Otherwise, we'll attempt to derive the key based on the address.
        // This will only work if we've already derived this address in the
        // past, since the wallet relies on a mapping of addr -> key.
        key, err := b.wallet.PrivKeyForAddress(addr)
        switch {
        // If we didn't find this key in the wallet, then there's a chance that
        // this is actually an "empty" key locator. The legacy KeyLocator
        // format failed to properly distinguish an empty key locator from the
        // very first in the index (0, 0).IsEmpty() == true.
        case waddrmgr.IsError(err, waddrmgr.ErrAddressNotFound) && emptyLocator:
                return b.deriveKeyByLocator(keyDesc.KeyLocator)

        case err != nil:
                return nil, err

        default:
                return key, nil
        }
}

// maybeTweakPrivKey examines the single and double tweak parameters on the
// passed sign descriptor and may perform a mapping on the passed private key
// in order to utilize the tweaks, if populated.
func maybeTweakPrivKey(signDesc *input.SignDescriptor,
        privKey *btcec.PrivateKey) (*btcec.PrivateKey, error) {

        var retPriv *btcec.PrivateKey
        switch {

        case signDesc.SingleTweak != nil:
                retPriv = input.TweakPrivKey(privKey,
                        signDesc.SingleTweak)

        case signDesc.DoubleTweak != nil:
                retPriv = input.DeriveRevocationPrivKey(privKey,
                        signDesc.DoubleTweak)

        default:
                retPriv = privKey
        }

        return retPriv, nil
}

// SignOutputRaw generates a signature for the passed transaction according to
// the data within the passed SignDescriptor.
//
// This is a part of the WalletController interface.
func (b *BtcWallet) SignOutputRaw(tx *wire.MsgTx,
        signDesc *input.SignDescriptor) (input.Signature, error) {

        witnessScript := signDesc.WitnessScript

        // First attempt to fetch the private key which corresponds to the
        // specified public key.
        privKey, err := b.fetchPrivKey(&signDesc.KeyDesc)
        if err != nil {
                return nil, err
        }

        // If a tweak (single or double) is specified, then we'll need to use
        // this tweak to derive the final private key to be used for signing
        // this output.
        privKey, err = maybeTweakPrivKey(signDesc, privKey)
        if err != nil {
                return nil, err
        }

        // In case of a taproot output any signature is always a Schnorr
        // signature, based on the new tapscript sighash algorithm.
        if txscript.IsPayToTaproot(signDesc.Output.PkScript) {
                sigHashes := txscript.NewTxSigHashes(
                        tx, signDesc.PrevOutputFetcher,
                )

                // Are we spending a script path or the key path? The API is
                // slightly different, so we need to account for that to get the
                // raw signature.
                var rawSig []byte
                switch signDesc.SignMethod {
                case input.TaprootKeySpendBIP0086SignMethod,
                        input.TaprootKeySpendSignMethod:

                        // This function tweaks the private key using the tap
                        // root key supplied as the tweak.
                        rawSig, err = txscript.RawTxInTaprootSignature(
                                tx, sigHashes, signDesc.InputIndex,
                                signDesc.Output.Value, signDesc.Output.PkScript,
                                signDesc.TapTweak, signDesc.HashType,
                                privKey,
                        )
                        if err != nil {
                                return nil, err
                        }

                case input.TaprootScriptSpendSignMethod:
                        leaf := txscript.TapLeaf{
                                LeafVersion: txscript.BaseLeafVersion,
                                Script:      witnessScript,
                        }
                        rawSig, err = txscript.RawTxInTapscriptSignature(
                                tx, sigHashes, signDesc.InputIndex,
                                signDesc.Output.Value, signDesc.Output.PkScript,
                                leaf, signDesc.HashType, privKey,
                        )
                        if err != nil {
                                return nil, err
                        }

                default:
                        return nil, fmt.Errorf("unknown sign method: %v",
                                signDesc.SignMethod)
                }

                // The signature returned above might have a sighash flag
                // attached if a non-default type was used. We'll slice this
                // off if it exists to ensure we can properly parse the raw
                // signature.
                sig, err := schnorr.ParseSignature(
                        rawSig[:schnorr.SignatureSize],
                )
                if err != nil {
                        return nil, err
                }

                return sig, nil
        }

        // TODO(roasbeef): generate sighash midstate if not present?

        amt := signDesc.Output.Value
        sig, err := txscript.RawTxInWitnessSignature(
                tx, signDesc.SigHashes, signDesc.InputIndex, amt,
                witnessScript, signDesc.HashType, privKey,
        )
        if err != nil {
                return nil, err
        }

        // Chop off the sighash flag at the end of the signature.
        return ecdsa.ParseDERSignature(sig[:len(sig)-1])
}

// ComputeInputScript generates a complete InputScript for the passed
// transaction with the signature as defined within the passed SignDescriptor.
// This method is capable of generating the proper input script for both
// regular p2wkh output and p2wkh outputs nested within a regular p2sh output.
//
// This is a part of the WalletController interface.
func (b *BtcWallet) ComputeInputScript(tx *wire.MsgTx,
        signDesc *input.SignDescriptor) (*input.Script, error) {

        // If a tweak (single or double) is specified, then we'll need to use
        // this tweak to derive the final private key to be used for signing
        // this output.
        privKeyTweaker := func(k *btcec.PrivateKey) (*btcec.PrivateKey, error) {
                return maybeTweakPrivKey(signDesc, k)
        }

        // Let the wallet compute the input script now.
        witness, sigScript, err := b.wallet.ComputeInputScript(
                tx, signDesc.Output, signDesc.InputIndex, signDesc.SigHashes,
                signDesc.HashType, privKeyTweaker,
        )
        if err != nil {
                return nil, err
        }

        return &input.Script{
                Witness:   witness,
                SigScript: sigScript,
        }, nil
}

// A compile time check to ensure that BtcWallet implements the Signer
// interface.
var _ input.Signer = (*BtcWallet)(nil)

// SignMessage attempts to sign a target message with the private key that
// corresponds to the passed key locator. If the target private key is unable to
// be found, then an error will be returned. The actual digest signed is the
// double SHA-256 of the passed message.
//
// NOTE: This is a part of the MessageSigner interface.
func (b *BtcWallet) SignMessage(keyLoc keychain.KeyLocator,
        msg []byte, doubleHash bool) (*ecdsa.Signature, error) {

        // First attempt to fetch the private key which corresponds to the
        // specified public key.
        privKey, err := b.fetchPrivKey(&keychain.KeyDescriptor{
                KeyLocator: keyLoc,
        })
        if err != nil {
                return nil, err
        }

        // Double hash and sign the data.
        var msgDigest []byte
        if doubleHash {
                msgDigest = chainhash.DoubleHashB(msg)
        } else {
                msgDigest = chainhash.HashB(msg)
        }
        return ecdsa.Sign(privKey, msgDigest), nil
}

// A compile time check to ensure that BtcWallet implements the MessageSigner
// interface.
var _ lnwallet.MessageSigner = (*BtcWallet)(nil)

1	package btcwallet
2
3	import (
4	"fmt"
5
6	"github.com/btcsuite/btcd/btcec/v2"
7	"github.com/btcsuite/btcd/btcec/v2/ecdsa"
8	"github.com/btcsuite/btcd/btcec/v2/schnorr"
9	"github.com/btcsuite/btcd/btcutil"
10	"github.com/btcsuite/btcd/btcutil/hdkeychain"
11	"github.com/btcsuite/btcd/btcutil/psbt"
12	"github.com/btcsuite/btcd/chaincfg/chainhash"
13	"github.com/btcsuite/btcd/txscript"
14	"github.com/btcsuite/btcd/wire"
15	"github.com/btcsuite/btcwallet/waddrmgr"
16	"github.com/btcsuite/btcwallet/walletdb"
17	"github.com/lightningnetwork/lnd/input"
18	"github.com/lightningnetwork/lnd/keychain"
19	"github.com/lightningnetwork/lnd/lnwallet"
20	)
21
22	// FetchOutpointInfo queries for the WalletController's knowledge of the passed
23	// outpoint. If the base wallet determines this output is under its control,
24	// then the original txout should be returned. Otherwise, a non-nil error value
25	// of ErrNotMine should be returned instead.
26	//
27	// This is a part of the WalletController interface.
28	func (b BtcWallet) FetchOutpointInfo(prevOut wire.OutPoint) (*lnwallet.Utxo,
29	error) {	4✔
30		4✔
31	prevTx, txOut, confirmations, err := b.wallet.FetchOutpointInfo(prevOut)	4✔
32	if err != nil {	8✔
33	return nil, err	4✔
34	}	4✔
35
36	// Then, we'll populate all of the information required by the struct.
37	addressType := lnwallet.UnknownAddressType	4✔
38	switch {	4✔
39	case txscript.IsPayToWitnessPubKeyHash(txOut.PkScript):	4✔
40	addressType = lnwallet.WitnessPubKey	4✔
41	case txscript.IsPayToScriptHash(txOut.PkScript):	4✔
42	addressType = lnwallet.NestedWitnessPubKey	4✔
43	case txscript.IsPayToTaproot(txOut.PkScript):	4✔
44	addressType = lnwallet.TaprootPubkey	4✔
45	}
46
47	return &lnwallet.Utxo{	4✔
48	AddressType: addressType,	4✔
49	Value: btcutil.Amount(txOut.Value),	4✔
50	PkScript: txOut.PkScript,	4✔
51	Confirmations: confirmations,	4✔
52	OutPoint: *prevOut,	4✔
53	PrevTx: prevTx,	4✔
54	}, nil	4✔
55	}
56
57	// FetchDerivationInfo queries for the wallet's knowledge of the passed
58	// pkScript and constructs the derivation info and returns it.
59	func (b *BtcWallet) FetchDerivationInfo(
60	pkScript []byte) (*psbt.Bip32Derivation, error) {	4✔
61		4✔
62	return b.wallet.FetchDerivationInfo(pkScript)	4✔
63	}	4✔
64
65	// ScriptForOutput returns the address, witness program and redeem script for a
66	// given UTXO. An error is returned if the UTXO does not belong to our wallet or
67	// it is not a managed pubKey address.
68	func (b BtcWallet) ScriptForOutput(output wire.TxOut) (
69	waddrmgr.ManagedPubKeyAddress, []byte, []byte, error) {	4✔
70		4✔
71	return b.wallet.ScriptForOutput(output)	4✔
72	}	4✔
73
74	// deriveFromKeyLoc attempts to derive a private key using a fully specified
75	// KeyLocator.
76	func deriveFromKeyLoc(scopedMgr *waddrmgr.ScopedKeyManager,
77	addrmgrNs walletdb.ReadWriteBucket,
78	keyLoc keychain.KeyLocator) (*btcec.PrivateKey, error) {	4✔
79		4✔
80	path := waddrmgr.DerivationPath{	4✔
81	InternalAccount: uint32(keyLoc.Family),	4✔
82	Account: uint32(keyLoc.Family),	4✔
83	Branch: 0,	4✔
84	Index: keyLoc.Index,	4✔
85	}	4✔
86	addr, err := scopedMgr.DeriveFromKeyPath(addrmgrNs, path)	4✔
87	if err != nil {	4✔
88	return nil, err	×
89	}	×
90
91	return addr.(waddrmgr.ManagedPubKeyAddress).PrivKey()	4✔
92	}
93
94	// deriveKeyByBIP32Path derives a key described by a BIP32 path. We expect the
95	// first three elements of the path to be hardened according to BIP44, so they
96	// must be a number >= 2^31.
97	func (b BtcWallet) deriveKeyByBIP32Path(path []uint32) (btcec.PrivateKey,
98	error) {	4✔
99		4✔
100	// Make sure we get a full path with exactly 5 elements. A path is	4✔
101	// either custom purpose one with 4 dynamic and one static elements:	4✔
102	// m/1017'/coinType'/keyFamily'/0/index	4✔
103	// Or a default BIP49/89 one with 5 elements:	4✔
104	// m/purpose'/coinType'/account'/change/index	4✔
105	const expectedDerivationPathDepth = 5	4✔
106	if len(path) != expectedDerivationPathDepth {	4✔
107	return nil, fmt.Errorf("invalid BIP32 derivation path, "+	×
108	"expected path length %d, instead was %d",	×
109	expectedDerivationPathDepth, len(path))	×
110	}	×
111
112	// Assert that the first three parts of the path are actually hardened
113	// to avoid under-flowing the uint32 type.
114	if err := assertHardened(path[0], path[1], path[2]); err != nil {	4✔
115	return nil, fmt.Errorf("invalid BIP32 derivation path, "+	×
116	"expected first three elements to be hardened: %w", err)	×
117	}	×
118
119	purpose := path[0] - hdkeychain.HardenedKeyStart	4✔
120	coinType := path[1] - hdkeychain.HardenedKeyStart	4✔
121	account := path[2] - hdkeychain.HardenedKeyStart	4✔
122	change, index := path[3], path[4]	4✔
123		4✔
124	// Is this a custom lnd internal purpose key?	4✔
125	switch purpose {	4✔
126	case keychain.BIP0043Purpose:	4✔
127	// Make sure it's for the same coin type as our wallet's	4✔
128	// keychain scope.	4✔
129	if coinType != b.chainKeyScope.Coin {	4✔
130	return nil, fmt.Errorf("invalid BIP32 derivation "+	×
131	"path, expected coin type %d, instead was %d",	×
132	b.chainKeyScope.Coin, coinType)	×
133	}	×
134
135	return b.deriveKeyByLocator(keychain.KeyLocator{	4✔
136	Family: keychain.KeyFamily(account),	4✔
137	Index: index,	4✔
138	})	4✔
139
140	// Is it a standard, BIP defined purpose that the wallet understands?
141	case waddrmgr.KeyScopeBIP0044.Purpose,
142	waddrmgr.KeyScopeBIP0049Plus.Purpose,
143	waddrmgr.KeyScopeBIP0084.Purpose,
144	waddrmgr.KeyScopeBIP0086.Purpose:	4✔
145
146	// We're going to continue below the switch statement to avoid
147	// unnecessary indentation for this default case.
148
149	// Currently, there is no way to import any other key scopes than the
150	// one custom purpose or three standard ones into lnd's wallet. So we
151	// shouldn't accept any other scopes to sign for.
152	default:	×
153	return nil, fmt.Errorf("invalid BIP32 derivation path, "+	×
154	"unknown purpose %d", purpose)	×
155	}
156
157	// Okay, we made sure it's a BIP49/84 key, so we need to derive it now.
158	// Interestingly, the btcwallet never actually uses a coin type other
159	// than 0 for those keys, so we need to make sure this behavior is
160	// replicated here.
161	if coinType != 0 {	4✔
162	return nil, fmt.Errorf("invalid BIP32 derivation path, coin " +	×
163	"type must be 0 for BIP49/84 btcwallet keys")	×
164	}	×
165
166	// We only expect to be asked to sign with key scopes that we know
167	// about. So if the scope doesn't exist, we don't create it.
168	scope := waddrmgr.KeyScope{	4✔
169	Purpose: purpose,	4✔
170	Coin: coinType,	4✔
171	}	4✔
172	scopedMgr, err := b.wallet.Manager.FetchScopedKeyManager(scope)	4✔
173	if err != nil {	4✔
174	return nil, fmt.Errorf("error fetching manager for scope %v: "+	×
175	"%w", scope, err)	×
176	}	×
177
178	// Let's see if we can hit the private key cache.
179	keyPath := waddrmgr.DerivationPath{	4✔
180	InternalAccount: account,	4✔
181	Account: account,	4✔
182	Branch: change,	4✔
183	Index: index,	4✔
184	}	4✔
185	privKey, err := scopedMgr.DeriveFromKeyPathCache(keyPath)	4✔
186	if err == nil {	8✔
187	return privKey, nil	4✔
188	}	4✔
189
190	// The key wasn't in the cache, let's fully derive it now.
191	err = walletdb.View(b.db, func(tx walletdb.ReadTx) error {	8✔
192	addrmgrNs := tx.ReadBucket(waddrmgrNamespaceKey)	4✔
193		4✔
194	addr, err := scopedMgr.DeriveFromKeyPath(addrmgrNs, keyPath)	4✔
195	if err != nil {	4✔
196	return fmt.Errorf("error deriving private key: %w", err)	×
197	}	×
198
199	privKey, err = addr.(waddrmgr.ManagedPubKeyAddress).PrivKey()	4✔
200	return err	4✔
201	})
202	if err != nil {	4✔
203	return nil, fmt.Errorf("error deriving key from path %#v: %w",	×
204	keyPath, err)	×
205	}	×
206
207	return privKey, nil	4✔
208	}
209
210	// assertHardened makes sure each given element is >= 2^31.
211	func assertHardened(elements ...uint32) error {	4✔
212	for idx, element := range elements {	8✔
213	if element < hdkeychain.HardenedKeyStart {	4✔
214	return fmt.Errorf("element at index %d is not hardened",	×
215	idx)	×
216	}	×
217	}
218
219	return nil	4✔
220	}
221
222	// deriveKeyByLocator attempts to derive a key stored in the wallet given a
223	// valid key locator.
224	func (b *BtcWallet) deriveKeyByLocator(
225	keyLoc keychain.KeyLocator) (*btcec.PrivateKey, error) {	4✔
226		4✔
227	// We'll assume the special lightning key scope in this case.	4✔
228	scopedMgr, err := b.wallet.Manager.FetchScopedKeyManager(	4✔
229	b.chainKeyScope,	4✔
230	)	4✔
231	if err != nil {	4✔
232	return nil, err	×
233	}	×
234
235	// First try to read the key from the cached store, if this fails, then
236	// we'll fall through to the method below that requires a database
237	// transaction.
238	path := waddrmgr.DerivationPath{	4✔
239	InternalAccount: uint32(keyLoc.Family),	4✔
240	Account: uint32(keyLoc.Family),	4✔
241	Branch: 0,	4✔
242	Index: keyLoc.Index,	4✔
243	}	4✔
244	privKey, err := scopedMgr.DeriveFromKeyPathCache(path)	4✔
245	if err == nil {	8✔
246	return privKey, nil	4✔
247	}	4✔
248
249	var key *btcec.PrivateKey	4✔
250	err = walletdb.Update(b.db, func(tx walletdb.ReadWriteTx) error {	8✔
251	addrmgrNs := tx.ReadWriteBucket(waddrmgrNamespaceKey)	4✔
252		4✔
253	key, err = deriveFromKeyLoc(scopedMgr, addrmgrNs, keyLoc)	4✔
254	if waddrmgr.IsError(err, waddrmgr.ErrAccountNotFound) {	4✔
255	// If we've reached this point, then the account	×
256	// doesn't yet exist, so we'll create it now to ensure	×
257	// we can sign.	×
258	acctErr := scopedMgr.NewRawAccount(	×
259	addrmgrNs, uint32(keyLoc.Family),	×
260	)	×
261	if acctErr != nil {	×
262	return acctErr	×
263	}	×
264
265	// Now that we know the account exists, we'll attempt
266	// to re-derive the private key.
267	key, err = deriveFromKeyLoc(	×
268	scopedMgr, addrmgrNs, keyLoc,	×
269	)	×
270	if err != nil {	×
271	return err	×
272	}	×
273	}
274
275	return err	4✔
276	})
277	if err != nil {	4✔
278	return nil, err	×
279	}	×
280
281	return key, nil	4✔
282	}
283
284	// fetchPrivKey attempts to retrieve the raw private key corresponding to the
285	// passed public key if populated, or the key descriptor path (if non-empty).
286	func (b *BtcWallet) fetchPrivKey(
287	keyDesc keychain.KeyDescriptor) (btcec.PrivateKey, error) {	4✔
288		4✔
289	// If the key locator within the descriptor isn't empty, then we can	4✔
290	// directly derive the keys raw.	4✔
291	emptyLocator := keyDesc.KeyLocator.IsEmpty()	4✔
292	if !emptyLocator \|\| keyDesc.PubKey == nil {	8✔
293	return b.deriveKeyByLocator(keyDesc.KeyLocator)	4✔
294	}	4✔
295
296	hash160 := btcutil.Hash160(keyDesc.PubKey.SerializeCompressed())	4✔
297	addr, err := btcutil.NewAddressWitnessPubKeyHash(hash160, b.netParams)	4✔
298	if err != nil {	4✔
299	return nil, err	×
300	}	×
301
302	// Otherwise, we'll attempt to derive the key based on the address.
303	// This will only work if we've already derived this address in the
304	// past, since the wallet relies on a mapping of addr -> key.
305	key, err := b.wallet.PrivKeyForAddress(addr)	4✔
306	switch {	4✔
307	// If we didn't find this key in the wallet, then there's a chance that
308	// this is actually an "empty" key locator. The legacy KeyLocator
309	// format failed to properly distinguish an empty key locator from the
310	// very first in the index (0, 0).IsEmpty() == true.
311	case waddrmgr.IsError(err, waddrmgr.ErrAddressNotFound) && emptyLocator:	4✔
312	return b.deriveKeyByLocator(keyDesc.KeyLocator)	4✔
313
314	case err != nil:	×
315	return nil, err	×
316
317	default:	4✔
318	return key, nil	4✔
319	}
320	}
321
322	// maybeTweakPrivKey examines the single and double tweak parameters on the
323	// passed sign descriptor and may perform a mapping on the passed private key
324	// in order to utilize the tweaks, if populated.
325	func maybeTweakPrivKey(signDesc *input.SignDescriptor,
326	privKey btcec.PrivateKey) (btcec.PrivateKey, error) {	4✔
327		4✔
328	var retPriv *btcec.PrivateKey	4✔
329	switch {	4✔
330
331	case signDesc.SingleTweak != nil:	4✔
332	retPriv = input.TweakPrivKey(privKey,	4✔
333	signDesc.SingleTweak)	4✔
334
335	case signDesc.DoubleTweak != nil:	4✔
336	retPriv = input.DeriveRevocationPrivKey(privKey,	4✔
337	signDesc.DoubleTweak)	4✔
338
339	default:	4✔
340	retPriv = privKey	4✔
341	}
342
343	return retPriv, nil	4✔
344	}
345
346	// SignOutputRaw generates a signature for the passed transaction according to
347	// the data within the passed SignDescriptor.
348	//
349	// This is a part of the WalletController interface.
350	func (b BtcWallet) SignOutputRaw(tx wire.MsgTx,
351	signDesc *input.SignDescriptor) (input.Signature, error) {	4✔
352		4✔
353	witnessScript := signDesc.WitnessScript	4✔
354		4✔
355	// First attempt to fetch the private key which corresponds to the	4✔
356	// specified public key.	4✔
357	privKey, err := b.fetchPrivKey(&signDesc.KeyDesc)	4✔
358	if err != nil {	4✔
359	return nil, err	×
360	}	×
361
362	// If a tweak (single or double) is specified, then we'll need to use
363	// this tweak to derive the final private key to be used for signing
364	// this output.
365	privKey, err = maybeTweakPrivKey(signDesc, privKey)	4✔
366	if err != nil {	4✔
367	return nil, err	×
368	}	×
369
370	// In case of a taproot output any signature is always a Schnorr
371	// signature, based on the new tapscript sighash algorithm.
372	if txscript.IsPayToTaproot(signDesc.Output.PkScript) {	8✔
373	sigHashes := txscript.NewTxSigHashes(	4✔
374	tx, signDesc.PrevOutputFetcher,	4✔
375	)	4✔
376		4✔
377	// Are we spending a script path or the key path? The API is	4✔
378	// slightly different, so we need to account for that to get the	4✔
379	// raw signature.	4✔
380	var rawSig []byte	4✔
381	switch signDesc.SignMethod {	4✔
382	case input.TaprootKeySpendBIP0086SignMethod,
383	input.TaprootKeySpendSignMethod:	4✔
384		4✔
385	// This function tweaks the private key using the tap	4✔
386	// root key supplied as the tweak.	4✔
387	rawSig, err = txscript.RawTxInTaprootSignature(	4✔
388	tx, sigHashes, signDesc.InputIndex,	4✔
389	signDesc.Output.Value, signDesc.Output.PkScript,	4✔
390	signDesc.TapTweak, signDesc.HashType,	4✔
391	privKey,	4✔
392	)	4✔
393	if err != nil {	4✔
394	return nil, err	×
395	}	×
396
397	case input.TaprootScriptSpendSignMethod:	4✔
398	leaf := txscript.TapLeaf{	4✔
399	LeafVersion: txscript.BaseLeafVersion,	4✔
400	Script: witnessScript,	4✔
401	}	4✔
402	rawSig, err = txscript.RawTxInTapscriptSignature(	4✔
403	tx, sigHashes, signDesc.InputIndex,	4✔
404	signDesc.Output.Value, signDesc.Output.PkScript,	4✔
405	leaf, signDesc.HashType, privKey,	4✔
406	)	4✔
407	if err != nil {	4✔
408	return nil, err	×
409	}	×
410
411	default:	×
412	return nil, fmt.Errorf("unknown sign method: %v",	×
413	signDesc.SignMethod)	×
414	}
415
416	// The signature returned above might have a sighash flag
417	// attached if a non-default type was used. We'll slice this
418	// off if it exists to ensure we can properly parse the raw
419	// signature.
420	sig, err := schnorr.ParseSignature(	4✔
421	rawSig[:schnorr.SignatureSize],	4✔
422	)	4✔
423	if err != nil {	4✔
424	return nil, err	×
425	}	×
426
427	return sig, nil	4✔
428	}
429
430	// TODO(roasbeef): generate sighash midstate if not present?
431
432	amt := signDesc.Output.Value	4✔
433	sig, err := txscript.RawTxInWitnessSignature(	4✔
434	tx, signDesc.SigHashes, signDesc.InputIndex, amt,	4✔
435	witnessScript, signDesc.HashType, privKey,	4✔
436	)	4✔
437	if err != nil {	4✔
438	return nil, err	×
439	}	×
440
441	// Chop off the sighash flag at the end of the signature.
442	return ecdsa.ParseDERSignature(sig[:len(sig)-1])	4✔
443	}
444
445	// ComputeInputScript generates a complete InputScript for the passed
446	// transaction with the signature as defined within the passed SignDescriptor.
447	// This method is capable of generating the proper input script for both
448	// regular p2wkh output and p2wkh outputs nested within a regular p2sh output.
449	//
450	// This is a part of the WalletController interface.
451	func (b BtcWallet) ComputeInputScript(tx wire.MsgTx,
452	signDesc input.SignDescriptor) (input.Script, error) {	4✔
453		4✔
454	// If a tweak (single or double) is specified, then we'll need to use	4✔
455	// this tweak to derive the final private key to be used for signing	4✔
456	// this output.	4✔
457	privKeyTweaker := func(k btcec.PrivateKey) (btcec.PrivateKey, error) {	8✔
458	return maybeTweakPrivKey(signDesc, k)	4✔
459	}	4✔
460
461	// Let the wallet compute the input script now.
462	witness, sigScript, err := b.wallet.ComputeInputScript(	4✔
463	tx, signDesc.Output, signDesc.InputIndex, signDesc.SigHashes,	4✔
464	signDesc.HashType, privKeyTweaker,	4✔
465	)	4✔
466	if err != nil {	4✔
467	return nil, err	×
468	}	×
469
470	return &input.Script{	4✔
471	Witness: witness,	4✔
472	SigScript: sigScript,	4✔
473	}, nil	4✔
474	}
475
476	// A compile time check to ensure that BtcWallet implements the Signer
477	// interface.
478	var _ input.Signer = (*BtcWallet)(nil)
479
480	// SignMessage attempts to sign a target message with the private key that
481	// corresponds to the passed key locator. If the target private key is unable to
482	// be found, then an error will be returned. The actual digest signed is the
483	// double SHA-256 of the passed message.
484	//
485	// NOTE: This is a part of the MessageSigner interface.
486	func (b *BtcWallet) SignMessage(keyLoc keychain.KeyLocator,
487	msg []byte, doubleHash bool) (*ecdsa.Signature, error) {	4✔
488		4✔
489	// First attempt to fetch the private key which corresponds to the	4✔
490	// specified public key.	4✔
491	privKey, err := b.fetchPrivKey(&keychain.KeyDescriptor{	4✔
492	KeyLocator: keyLoc,	4✔
493	})	4✔
494	if err != nil {	4✔
495	return nil, err	×
496	}	×
497
498	// Double hash and sign the data.
499	var msgDigest []byte	4✔
500	if doubleHash {	8✔
501	msgDigest = chainhash.DoubleHashB(msg)	4✔
502	} else {	4✔
503	msgDigest = chainhash.HashB(msg)	×
504	}	×
505	return ecdsa.Sign(privKey, msgDigest), nil	4✔
506	}
507
508	// A compile time check to ensure that BtcWallet implements the MessageSigner
509	// interface.
510	var _ lnwallet.MessageSigner = (*BtcWallet)(nil)

lightningnetwork / lnd / 12199391122

Source File Press 'n' to go to next uncovered line, 'b' for previous

Source File
Press 'n' to go to next uncovered line, 'b' for previous