@yume-chan/adb

@yume-chan/adb

TypeScript implementation of Android Debug Bridge (ADB) protocol.

WARNING: The public API is UNSTABLE. If you have any questions, please open an issue.

• Compatibility
  • Basic usage
  • Use without bundlers
• Connection
  • Backend
    • connect
• Authentication
  • AdbCredentialStore
    • generateKey
    • iterateKeys
    • Implementations
  • AdbAuthenticator
  • authenticate
• Stream multiplex
• Commands
  • subprocess
    • raw mode
    • pty mode
  • usb
  • tcpip
  • sync
    • LIST
    • LIS2
    • STAT
    • LST2
    • STA2
    • RECV
    • RCV2
    • SEND
    • SND2
• Useful links

Compatibility

Here is a list of features, their used APIs, and their compatibilities. If an optional feature is not actually used, its requirements can be ignored.

Some features can be polyfilled to support older runtimes, but this library doesn't ship with any polyfills.

Each backend may have different requirements.

Basic usage

	Chrome	Edge	Firefox	Internet Explorer	Safari	Node.js
@yume-chan/struct1	67	79	68	No	14	8.32, 11
Overall	67	79	No	No	14.1	16.5

¹ uint64 and string are used.

² TextEncoder and TextDecoder are only available in util module. Need to be assigned to globalThis.

Use without bundlers

	Chrome	Edge	Firefox	Internet Explorer	Safari	Node.js
Top-level await	89	89	89	No	15	14.8

Connection

This library doesn't tie to a specific transportation method.

Instead, a Backend is responsible for transferring data in its own way (USB, WebSocket, TCP, etc).

Backend

connect

connect(): ValueOrPromise<ReadableWritablePair<AdbPacketCore, AdbPacketInit>>

Connect to a device and create a pair of AdbPacket streams.

The backend, instead of the core library, is responsible for serializing and deserializing the packets. Because it's extreme slow for WebUSB backend (@yume-chan/adb-backend-webusb) to read packets with unknown size.

Authentication

For how does ADB authentication work, see https://chensi.moe/blog/2020/09/30/webadb-part2-connection/#auth.

In this library, authentication comes in two parts:

AdbCredentialStore

An interface to generate, store and iterate ADB private keys on each runtime. (Because Node.js and Browsers have different APIs to do this)

generateKey

generateKey(): ValueOrPromise<Uint8Array>

Generate and store a RSA private key with modulus length 2048 and public exponent 65537.

The returned Uint8Array is the private key in PKCS #8 format.

iterateKeys

iterateKeys(): Iterator<ArrayBuffer> | AsyncIterator<ArrayBuffer>

Synchronously or asynchronously iterate through all stored RSA private keys.

Each call to iterateKeys must return a different iterator that iterate through all stored keys.

Implementations

The @yume-chan/adb-credential-web package contains a AdbWebCredentialStore implementation using Web Crypto API for generating keys and Web Storage API for storing keys.

AdbAuthenticator

An AdbAuthenticator generates AUTH responses for each AUTH request from server.

This package contains AdbSignatureAuthenticator and AdbPublicKeyAuthenticator, the two basic modes.

authenticate

static async authenticate(
    connection: ReadableWritablePair<AdbPacketCore, AdbPacketCore>,
    credentialStore: AdbCredentialStore,
    authenticators = AdbDefaultAuthenticators,
): Promise<Adb>

Call this method to authenticate the connection and create an Adb instance.

If an authentication process failed, it's possible to call authenticate again on the same connection (AdbPacket stream pair). Every time the device receives a CNXN packet, it resets all internal state, and starts a new authentication process.

Stream multiplex

ADB commands are all based on streams. Multiple streams can send and receive at the same time in one connection.

1. Client sends an OPEN packet to create a stream.
2. Server responds with OKAY or FAIL.
3. Client and server read/write on the stream.
4. Client/server sends a CLSE to close the stream.

Commands

subprocess

ADB has two subprocess invocation modes and two data protocols (4 combinations).

raw mode

In raw mode, Shell protocol transfers stdout and stderr separately. It also supports returning exit code.

	Legacy protocol	Shell Protocol
Feature flag	-	shell_v2
Implementation	AdbNoneSubprocessProtocol	AdbShellSubprocessProtocol
Splitting stdout and stderr	No	Yes
Returning exit code	No	Yes

Use spawn method to create a subprocess in raw mode.

pty mode

In PTY mode, the subprocess has a pseudo-terminal, so it can send special control sequences like clear screen and set cursor position. The two protocols both send data in stdout, but Shell Protocol also supports resizing the terminal from client.

	Legacy protocol	Shell Protocol
Feature flag	-	shell_v2
Implementation	AdbNoneSubprocessProtocol	AdbShellSubprocessProtocol
Resizing window	No	Yes

Use shell method to create a subprocess in PTY mode.

usb

Disable ADB over WiFi.

tcpip

Enable ADB over WiFi.

sync

Client and server will communicate with another protocol on the opened stream.

LIST

Request server to list the content of a folder.

LIS2

Version 2 of the LIST command, contains more information.

Supported on devices with ls_v2 feature.

STAT

Request server to return the information of a file.

If path is a symbolic link, the returned information is about the link itself.

So it's actually the lstat system call.

LST2

Version 2 of the STAT command, contains more information.

Supported on devices with stat_v2 feature.

STA2

Basically identical to LST2, but if path is a symbolic link, the information is about the file it refers to.

Supported on devices with stat_v2 feature.

RECV

Request server to send the content of a file.

RCV2

(Not Implemented)

Version 2 of the RECV command.

Supported on devices with sendrecv_v2 feature.

SEND

(Not Implemented)

Send a file onto server's file system.

SND2

(Not Implemented)

Version 2 of the SEND command.

Supported on devices with sendrecv_v2 feature.

Useful links

• ADB protocol overview
• ADB commands