@ledgerhq/devices

Logic for all Ledger devices.

API

Table of Contents

• receiveAPDU
  • Parameters
• createChunkedBuffers
  • Parameters
• sendAPDU
  • Parameters
• createHIDframing
  • Parameters
• makeBlocks
  • Parameters
• reduceResponse
  • Parameters
• getReducedResult
  • Parameters
• IIGenericHID
• ledgerUSBVendorId
• getDeviceModel
  • Parameters
• identifyTargetId
  • Parameters
• identifyUSBProductId
  • Parameters
• getBluetoothServiceUuids
• getInfosForServiceUuid
  • Parameters
• DeviceModel
• BluetoothInfos

receiveAPDU

Parses a raw stream coming from a BLE communication into an APDU response

Parameters

• rawStream Observable<(Buffer | Error)> An observable containing the raw stream as emitted buffers

• options {context: TraceContext?} Optional options containing:* context An optional context object for log/tracing strategy (optional, default {})

  • options.context

Returns Observable<Buffer> An observable containing the APDU response as one emitted buffer

createChunkedBuffers

Creates a list of chunked buffer from one buffer

If this is using a Node buffer: the chunked buffers reference to the same memory as the original buffer. If this is using a Uint8Array: each part of the original buffer is copied into the chunked buffers

Parameters

• buffer Buffer a Node Buffer, or a Uint8Array
• sizeForIndex function (arg0: number): number A function that takes an index (on the buffer) and returns the size of the chunk at that index

Returns Array<Buffer> a list of chunked buffers

sendAPDU

Sends an APDU by encoding it into chunks and sending the chunks using the given write function

Parameters

• write function (arg0: Buffer): Promise<void> The function to send each chunk to the device

• apdu Buffer

• mtuSize number The negotiated maximum size of the data to be sent in one chunk

• options {context: TraceContext?} Optional options containing:* context An optional context object for log/tracing strategy (optional, default {})

  • options.context

Returns Observable<Buffer> An observable that will only emit if an error occurred, otherwise it will complete

createHIDframing

Object to handle HID frames (encoding and decoding)

Parameters

• channel number
• packetSize number The HID protocol packet size in bytes (usually 64)

makeBlocks

Frames/encodes an APDU message into HID USB packets/frames

Parameters

• apdu Buffer The APDU message to send, in a Buffer containing [cla, ins, p1, p2, data length, data(if not empty)]

Returns Array<Buffer> an array of HID USB frames ready to be sent

reduceResponse

Reduces HID USB packets/frames to one response.

Parameters

• acc ResponseAcc The value resulting from (accumulating) the previous call of reduceResponse. On first call initialized to initialAcc. The accumulator enables handling multi-frames messages.
• chunk Buffer Current chunk to reduce into accumulator

Returns ResponseAcc An accumulator value updated with the current chunk

getReducedResult

Returns the response message that has been reduced from the HID USB frames

Parameters

• acc ResponseAcc The accumulator

Returns (Buffer | null | undefined) A Buffer containing the cleaned response message, or null if no response message, or undefined if the accumulator is incorrect (message length is not valid)

IIGenericHID

The USB product IDs will be defined as MMII, encoding a model (MM) and an interface bitfield (II)

• Model Ledger Nano S : 0x10 Ledger Blue : 0x00 Ledger Nano X : 0x40

• Interface support bitfield Generic HID : 0x01 Keyboard HID : 0x02 U2F : 0x04 CCID : 0x08 WebUSB : 0x10

Type: number

ledgerUSBVendorId

Type: number

getDeviceModel

Parameters

• id DeviceModelId

Returns DeviceModel

identifyTargetId

Given a targetId, return the deviceModel associated to it, based on the first two bytes.

Parameters

• targetId number

Returns (DeviceModel | null | undefined)

identifyUSBProductId

From a given USB product id, return the deviceModel associated to it.

The mapping from the product id is only based on the 2 most significant bytes. For example, Stax is defined with a product id of 0x60ii, a product id 0x6011 would be mapped to it.

Parameters

• usbProductId number

Returns (DeviceModel | null | undefined)

getBluetoothServiceUuids

Returns Array<string>

getInfosForServiceUuid

Parameters

• uuid string

Returns (BluetoothInfos | undefined)

DeviceModel

BluetoothInfos