# Tron Signer Kit This module provides the implementation of the Ledger Tron signer of the Device Management Kit. It enables interaction with the Tron (TRX) application on a Ledger device including: - Retrieving the Tron address using a given derivation path - Signing a Tron transaction - Signing a Tron transaction hash - Signing a personal message - Retrieving the app configuration - Computing an ECDH shared secret with a peer public key ## 🔹 Index 1. [How it works](#-how-it-works) 2. [Installation](#-installation) 3. [Initialisation](#-initialisation) 4. [Use Cases](#-use-cases) - [Get App Configuration](#use-case-1-get-app-configuration) - [Get Address](#use-case-2-get-address) - [Sign Transaction](#use-case-3-sign-transaction) - [Sign Transaction Hash](#use-case-4-sign-transaction-hash) - [Sign Personal Message](#use-case-5-sign-personal-message) - [Get ECDH Secret](#use-case-6-get-ecdh-secret) 5. [Observable Behavior](#-observable-behavior) 6. [Example](#-example) ## 🔹 How it works The Ledger Tron Signer utilizes the advanced capabilities of the Ledger device to provide secure operations for end users. It takes advantage of the interface provided by the Device Management Kit to establish communication with the Ledger device and execute various operations. The communication with the Ledger device is performed using [APDU](https://en.wikipedia.org/wiki/Smart_card_application_protocol_data_unit)s (Application Protocol Data Units), which are encapsulated within the `Command` object. These commands are then organized into tasks, allowing for the execution of complex operations with one or more APDUs. The tasks are further encapsulated within `DeviceAction` objects to handle different real-world scenarios. Finally, the Signer exposes dedicated and independent use cases that can be directly utilized by end users. ## 🔹 Installation > **Note:** This module is not standalone; it depends on the [@ledgerhq/device-management-kit](https://github.com/LedgerHQ/device-sdk-ts/tree/develop/packages/device-management-kit) package, so you need to install it first. To install the `device-signer-kit-tron` package, run the following command: ```sh npm install @ledgerhq/device-signer-kit-tron ``` ## 🔹 Initialisation To initialise a Tron signer instance, you need a Ledger Device Management Kit instance and the ID of the session of the connected device. Use the `SignerTrxBuilder`: ```typescript const signerTrx = new SignerTrxBuilder({ dmk, sessionId }).build(); ``` ## 🔹 Use Cases The `SignerTrxBuilder.build()` method will return a `SignerTrx` instance that exposes 6 dedicated methods, each of which calls an independent use case. Each use case will return an object that contains an observable and a method called `cancel`. > **Note:** Tron uses the BIP44 coin type `195`, so derivation paths look like `"44'/195'/0'/0/0"`. --- ### Use Case 1: Get App Configuration This method allows users to retrieve the app configuration from the Ledger device. ```typescript const { observable, cancel } = signerTrx.getAppConfiguration(); ``` #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript type AppConfiguration = { version: string; versionN: number; allowData: boolean; allowContract: boolean; truncateAddress: boolean; signByHash: boolean; }; ``` - `cancel` A function to cancel the action on the Ledger device. --- ### Use Case 2: Get Address This method allows users to retrieve the Tron address based on a given `derivationPath`. ```typescript const { observable, cancel } = signerTrx.getAddress(derivationPath, options); ``` #### **Parameters** - `derivationPath` - **Required** - **Type:** `string` (e.g., `"44'/195'/0'/0/0"`) - The derivation path used for the Tron address. See [here](https://www.ledger.com/blog/understanding-crypto-addresses-and-derivation-paths) for more information. - `options` - Optional - Type: `AddressOptions` ```typescript type AddressOptions = { checkOnDevice?: boolean; skipOpenApp?: boolean; }; ``` - `checkOnDevice`: An optional boolean indicating whether user confirmation on the device is required (`true`) or not (`false`). - `skipOpenApp`: An optional boolean indicating whether to skip opening the Tron app automatically (`true`) or not (`false`). #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript type GetAddressCommandResponse = { publicKey: string; // hex-encoded public key address: string; // Base58 Tron address (e.g. "TWdnWBzFdBP1b8sqZ5RcFDbkV3sBmnxsYu") chainCode?: string; }; ``` - `cancel` A function to cancel the action on the Ledger device. --- ### Use Case 3: Sign Transaction This method allows users to sign a Tron transaction. ```typescript const { observable, cancel } = signerTrx.signTransaction( derivationPath, transaction, options, ); ``` #### **Parameters** - `derivationPath` - **Required** - **Type:** `string` (e.g., `"44'/195'/0'/0/0"`) - The derivation path used for the Tron transaction. - `transaction` - **Required** - **Type:** `Uint8Array` - The serialized (protobuf) transaction to be signed. - `options` - Optional - Type: `TransactionOptions` ```typescript type TransactionOptions = { skipOpenApp?: boolean; }; ``` - `skipOpenApp`: An optional boolean indicating whether to skip opening the Tron app automatically (`true`) or not (`false`). #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript type Signature = Uint8Array; // 65-byte signature ``` - `cancel` A function to cancel the action on the Ledger device. --- ### Use Case 4: Sign Transaction Hash This method allows users to sign a raw Tron transaction hash. Signing a bare hash is a blind-signing operation, so use it with caution. ```typescript const { observable, cancel } = signerTrx.signTransactionHash( derivationPath, transactionHash, options, ); ``` #### **Parameters** - `derivationPath` - **Required** - **Type:** `string` (e.g., `"44'/195'/0'/0/0"`) - The derivation path used for the Tron transaction hash. - `transactionHash` - **Required** - **Type:** `Uint8Array` - The 32-byte transaction hash to be signed. - `options` - Optional - Type: `TransactionOptions` ```typescript type TransactionOptions = { skipOpenApp?: boolean; }; ``` - `skipOpenApp`: An optional boolean indicating whether to skip opening the Tron app automatically (`true`) or not (`false`). #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript type Signature = Uint8Array; // 65-byte signature ``` - `cancel` A function to cancel the action on the Ledger device. --- ### Use Case 5: Sign Personal Message This method allows users to sign a personal message (TRON's `signMessage` / TIP-191 flow). ```typescript const { observable, cancel } = signerTrx.signPersonalMessage( derivationPath, message, options, ); ``` #### **Parameters** - `derivationPath` - **Required** - **Type:** `string` (e.g., `"44'/195'/0'/0/0"`) - The derivation path used to sign the message. - `message` - **Required** - **Type:** `string | Uint8Array` - The message to be signed, either as a UTF-8 string or as raw bytes. - `options` - Optional - Type: `MessageOptions` ```typescript type MessageOptions = { skipOpenApp?: boolean; }; ``` - `skipOpenApp`: An optional boolean indicating whether to skip opening the Tron app automatically (`true`) or not (`false`). #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript type Signature = Uint8Array; // 65-byte signature ``` - `cancel` A function to cancel the action on the Ledger device. --- ### Use Case 6: Get ECDH Secret This method computes an ECDH shared secret between the device key (derived from the BIP32 path) and a peer's uncompressed secp256k1 public key. The operation is shown on the device for approval. ```typescript const { observable, cancel } = signerTrx.getECDHSecret( derivationPath, publicKey, options, ); ``` #### **Parameters** - `derivationPath` - **Required** - **Type:** `string` (e.g., `"44'/195'/0'/0/0"`) - The derivation path used to derive the device key. - `publicKey` - **Required** - **Type:** `Uint8Array` - The peer's uncompressed secp256k1 public key (65 bytes, `0x04 || X || Y`). - `options` - Optional - Type: `EcdhOptions` ```typescript type EcdhOptions = { skipOpenApp?: boolean; }; ``` - `skipOpenApp`: An optional boolean indicating whether to skip opening the Tron app automatically (`true`) or not (`false`). #### **Returns** - `observable` Emits DeviceActionState updates, including the following details: ```typescript // The 65-byte ECDH shared point (0x04 || X || Y). type GetECDHSecretDAOutput = Uint8Array; ``` - `cancel` A function to cancel the action on the Ledger device. --- ## 🔹 Observable Behavior Each method returns an [Observable](https://rxjs.dev/guide/observable) emitting updates structured as [`DeviceActionState`](https://github.com/LedgerHQ/device-sdk-ts/blob/develop/packages/device-management-kit/src/api/device-action/model/DeviceActionState.ts). These updates reflect the operation's progress and status: - **NotStarted**: The operation hasn't started. - **Pending**: The operation is in progress and may require user interaction. - **Stopped**: The operation was canceled or stopped. - **Completed**: The operation completed successfully, with results available. - **Error**: An error occurred. **Example Observable Subscription:** ```typescript observable.subscribe({ next: (state: DeviceActionState) => { switch (state.status) { case DeviceActionStatus.NotStarted: { console.log("The action is not started yet."); break; } case DeviceActionStatus.Pending: { const { intermediateValue: { requiredUserInteraction }, } = state; // Access the intermediate value here, explained below console.log( "The action is pending and the intermediate value is: ", intermediateValue, ); break; } case DeviceActionStatus.Stopped: { console.log("The action has been stopped."); break; } case DeviceActionStatus.Completed: { const { output } = state; // Access the output of the completed action here console.log("The action has been completed: ", output); break; } case DeviceActionStatus.Error: { const { error } = state; // Access the error here if occurred console.log("An error occurred during the action: ", error); break; } } }, }); ``` **Intermediate Values in Pending Status:** When the status is DeviceActionStatus.Pending, the state will include an `intermediateValue` object that provides useful information for interaction: ```typescript const { requiredUserInteraction } = intermediateValue; switch (requiredUserInteraction) { case UserInteractionRequired.VerifyAddress: { // User needs to verify the address displayed on the device console.log("User needs to verify the address displayed on the device."); break; } case UserInteractionRequired.SignTransaction: { // User needs to sign the transaction displayed on the device console.log("User needs to sign the transaction displayed on the device."); break; } case UserInteractionRequired.SignPersonalMessage: { // User needs to sign the message displayed on the device console.log("User needs to sign the message displayed on the device."); break; } case UserInteractionRequired.None: { // No user action required console.log("No user action needed."); break; } case UserInteractionRequired.UnlockDevice: { // User needs to unlock the device console.log("The user needs to unlock the device."); break; } case UserInteractionRequired.ConfirmOpenApp: { // User needs to confirm on the device to open the app console.log("The user needs to confirm on the device to open the app."); break; } default: // Type guard to ensure all cases are handled const uncaughtUserInteraction: never = requiredUserInteraction; console.error("Unhandled user interaction case:", uncaughtUserInteraction); } ``` ## 🔹 Example We encourage you to explore the Tron Signer by trying it out in our online [sample application](https://app.devicesdk.ledger-test.com/). Experience how it works and see its capabilities in action. Of course, you will need a Ledger device connected.