From 978f1f3f6d44d1e71c85b5ea2ac13e80cde773bb Mon Sep 17 00:00:00 2001 From: Dmitry Yu Okunev Date: Mon, 25 Jun 2018 23:52:55 +0200 Subject: Implemented the support of Trezor devices. --- internal/readpassword/trezor.go | 84 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 75 insertions(+), 9 deletions(-) diff --git a/internal/readpassword/trezor.go b/internal/readpassword/trezor.go index 45edfd8..be9c22a 100644 --- a/internal/readpassword/trezor.go +++ b/internal/readpassword/trezor.go @@ -5,31 +5,97 @@ import ( "github.com/rfjakob/gocryptfs/internal/exitcodes" "github.com/rfjakob/gocryptfs/internal/tlog" + + "github.com/xaionaro-go/cryptoWallet" + "github.com/xaionaro-go/cryptoWallet/vendors" ) const ( // TrezorPayloadLen is the length of the payload data passed to Trezor's // CipherKeyValue function. - TrezorPayloadLen = 32 + TrezorPayloadLen = 32 + trezorNonce = "" // the "nonce" is optional and has no use in here + trezorKeyName = "gocryptfs" + trezorKeyDerivationPath = `m/10019'/0'` ) -// Trezor reads 16 deterministically derived bytes from a +func trezorGetPin(title, description, ok, cancel string) ([]byte, error) { + return Once("", title), nil +} +func trezorGetConfirm(title, description, ok, cancel string) (bool, error) { + return false, nil // do not retry on connection failure +} + +// Trezor reads 32 deterministically derived bytes from a // SatoshiLabs Trezor USB security module. // The bytes are pseudorandom binary data and may contain null bytes. -// This function either succeeds and returns 16 bytes or calls os.Exit to end +// This function either succeeds and returns 32 bytes or calls os.Exit to end // the application. func Trezor(payload []byte) []byte { if len(payload) != TrezorPayloadLen { tlog.Fatal.Printf("Invalid TrezorPayload length: wanted %d, got %d bytes\n", TrezorPayloadLen, len(payload)) os.Exit(exitcodes.LoadConf) } - var err error - // TODO try to read bytes here.... - // Handle errors + + // Find all trezor devices + trezors := cryptoWallet.Find(cryptoWallet.Filter{ + VendorID: &[]uint16{vendors.GetVendorID("satoshilabs")}[0], + ProductIDs: []uint16{1 /* Trezor One */}, + }) + + // ATM, we require to one and only one trezor device to be connected. + // The support of multiple trezor devices is not implemented, yet. + if len(trezors) == 0 { + tlog.Fatal.Printf("Trezor device is not found. Check the connection.") + os.Exit(exitcodes.TrezorError) + } + if len(trezors) > 1 { + tlog.Fatal.Printf("It's more than one Trezor device connected. This case is not implemented, yet. The number of currently connected devices: %v.", len(trezors)) + os.Exit(exitcodes.TrezorError) + } + + // Using the first found device + trezor := trezors[0] + + // Trezor may ask for PIN or Passphrase. Setting the handler for this case. + trezor.SetGetPinFunc(trezorGetPin) + + // In some cases (like lost connection to the Trezor device and cannot + // reconnect) it's required to get a confirmation from the user to + // retry to reconnect. Setting the handler for this case. + trezor.SetGetConfirmFunc(trezorGetConfirm) + + // To reset the state of the device and check if it's initialized. + // If device is not initialized then trezor.Reset() will return an + // error. + err := trezor.Reset() if err != nil { - tlog.Fatal.Printf("xxx some error was encountered...") + tlog.Fatal.Printf("Cannot reset the Trezor device. Error: %v", err.Error()) os.Exit(exitcodes.TrezorError) } - tlog.Warn.Println("XXX readpassword.Trezor(): not implemented yet - returning hardcoded dummy bytes XXX") - return []byte("1234567890123456") + + // To generate a deterministic key we trying to decrypt our + // predefined constant key using the Trezor device. The resulting key + // will depend on next variables: + // * the Trezor master key; + // * the passphrase (passed to the Trezor). + // + // The right key will be received only if both values (mentioned + // above) are correct. + // + // Note: + // Also the resulting key depends on this values (that we defined as + // constants above): + // * the key derivation path; + // * the "encrypted" payload; + // * the nonce; + // * the key name. + key, err := trezor.DecryptKey(trezorKeyDerivationPath, payload, []byte(trezorNonce), trezorKeyName) + if err != nil { + tlog.Fatal.Printf("Cannot get the key from the Trezor device. Error description:\n\t%v", err.Error()) + os.Exit(exitcodes.TrezorError) + } + + // Everything ok + return key } -- cgit v1.2.3