|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "fmt" |
| 5 | + |
| 6 | + chantools_lnd "github.com/lightninglabs/chantools/lnd" |
| 7 | + "github.com/lightningnetwork/lnd/keychain" |
| 8 | + "github.com/spf13/cobra" |
| 9 | + "github.com/tv42/zbase32" |
| 10 | +) |
| 11 | + |
| 12 | +var ( |
| 13 | + signedMsgPrefix = []byte("Lightning Signed Message:") |
| 14 | +) |
| 15 | + |
| 16 | +type signMessageCommand struct { |
| 17 | + Msg string |
| 18 | + |
| 19 | + rootKey *rootKey |
| 20 | + cmd *cobra.Command |
| 21 | +} |
| 22 | + |
| 23 | +func newSignMessageCommand() *cobra.Command { |
| 24 | + cc := &signMessageCommand{} |
| 25 | + cc.cmd = &cobra.Command{ |
| 26 | + Use: "signmessage", |
| 27 | + Short: "Sign a message with the node's private key.", |
| 28 | + Long: `Sign msg with the resident node's private key. |
| 29 | + Returns the signature as a zbase32 string.`, |
| 30 | + Example: `chantools signmessage --msg=foobar`, |
| 31 | + RunE: cc.Execute, |
| 32 | + } |
| 33 | + cc.cmd.Flags().StringVar( |
| 34 | + &cc.Msg, "msg", "", "the message to sign", |
| 35 | + ) |
| 36 | + |
| 37 | + cc.rootKey = newRootKey(cc.cmd, "decrypting the backup") |
| 38 | + |
| 39 | + return cc.cmd |
| 40 | +} |
| 41 | + |
| 42 | +func (c *signMessageCommand) Execute(_ *cobra.Command, _ []string) error { |
| 43 | + if c.Msg == "" { |
| 44 | + return fmt.Errorf("please enter a valid msg") |
| 45 | + } |
| 46 | + |
| 47 | + extendedKey, err := c.rootKey.read() |
| 48 | + if err != nil { |
| 49 | + return fmt.Errorf("error reading root key: %w", err) |
| 50 | + } |
| 51 | + |
| 52 | + signer := &chantools_lnd.Signer{ |
| 53 | + ExtendedKey: extendedKey, |
| 54 | + ChainParams: chainParams, |
| 55 | + } |
| 56 | + |
| 57 | + // Create the key locator for the node key. |
| 58 | + keyLocator := keychain.KeyLocator{ |
| 59 | + Family: keychain.KeyFamilyNodeKey, |
| 60 | + Index: 0, |
| 61 | + } |
| 62 | + |
| 63 | + // Fetch the private key for node key. |
| 64 | + privKey, err := signer.FetchPrivKey(&keychain.KeyDescriptor{ |
| 65 | + KeyLocator: keyLocator, |
| 66 | + }) |
| 67 | + if err != nil { |
| 68 | + return err |
| 69 | + } |
| 70 | + |
| 71 | + // Create a new signer. |
| 72 | + privKeyMsgSigner := keychain.NewPrivKeyMessageSigner( |
| 73 | + privKey, keyLocator, |
| 74 | + ) |
| 75 | + |
| 76 | + // Prepend the special lnd prefix. |
| 77 | + // See: https://github.com/lightningnetwork/lnd/blob/63e698ec4990e678089533561fd95cfd684b67db/rpcserver.go#L1576 . |
| 78 | + msg := []byte(c.Msg) |
| 79 | + msg = append(signedMsgPrefix, msg...) |
| 80 | + sigBytes, err := privKeyMsgSigner.SignMessageCompact(msg, true) |
| 81 | + if err != nil { |
| 82 | + return err |
| 83 | + } |
| 84 | + |
| 85 | + // Encode the signature. |
| 86 | + sig := zbase32.EncodeToString(sigBytes) |
| 87 | + fmt.Println(sig) |
| 88 | + |
| 89 | + return nil |
| 90 | +} |
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