<h1 align="center">gowidevine</h1> <p align="center"> 🐭 Go implementation of Google's Widevine DRM CDM (Content Decryption Module) </p> <p align="center"> <img src="https://img.shields.io/github/go-mod/go-version/iyear/gowidevine?style=flat-square" alt=""> <img src="https://img.shields.io/github/license/iyear/gowidevine?style=flat-square" alt=""> <img src="https://img.shields.io/github/actions/workflow/status/iyear/gowidevine/ci.yml?branch=master&style=flat-square" alt=""> <img src="https://img.shields.io/github/v/release/iyear/gowidevine?color=red&style=flat-square" alt=""> </p>

Features

[x] Implementation of Widevine CDM/Device/Protobuf
[x] Decrypt MP4 with Widevine key
[x] Covered by realistic data tests
[x] Few third-party dependencies
[ ] License proxy server/client

Getting Started

Install

You first need Go installed (version 1.18+ is required), then you can use the below Go command to install gowidevine:

go get -u github.com/iyear/gowidevine

Import

Import the package into your project:

import "github.com/iyear/gowidevine"

Usage

package main

import (
    "bytes"
    "fmt"
    "io"
    "net/http"

    widevine "github.com/iyear/gowidevine"
    "github.com/iyear/gowidevine/widevinepb"
)

var (
    clientID   = []byte("foo")
    privateKey = []byte("bar")
    psshData   = []byte("baz")
)

func main() {
    keys, err := getKeys()
    if err != nil {
        panic(err)
    }
    if len(keys) == 0 {
        panic("no keys")
    }

    for _, key := range keys {
        fmt.Printf("type: %s, id: %x, key: %x\n", key.Type, key.ID, key.Key)
    }

    err = widevine.DecryptMP4Auto(bytes.NewBufferString("encrypted data"),
        keys, io.Discard)
    if err != nil {
        panic(err)
    }
}

func getKeys() ([]*widevine.Key, error) {
    // Create device from raw data or from wvd file
    device, err := widevine.NewDevice(
        widevine.FromRaw(clientID, privateKey),
        // widevine.FromWVD(bytes.NewReader([]byte("baz"))),
    )
    if err != nil {
        return nil, fmt.Errorf("create device: %w", err)
    }
    // Create CDM
    cdm := widevine.NewCDM(device)

    // Parse PSSH
    pssh, err := widevine.NewPSSH(psshData)
    if err != nil {
        return nil, fmt.Errorf("parse pssh: %w", err)
    }

    // Get license challenge
    challenge, parseLicense, err := cdm.GetLicenseChallenge(pssh, widevinepb.LicenseType_AUTOMATIC, false)
    if err != nil {
        return nil, fmt.Errorf("get license challenge: %w", err)
    }
    // Or use privacy mode
    cert, err := getServiceCert()
    if err != nil {
        return nil, fmt.Errorf("get service cert: %w", err)
    }
    challenge, parseLicense, err = cdm.GetLicenseChallenge(pssh, widevinepb.LicenseType_AUTOMATIC, true, cert)
    if err != nil {
        return nil, fmt.Errorf("get license challenge: %w", err)
    }

    // Send challenge to license server
    resp, err := http.DefaultClient.Do(&http.Request{Body: io.NopCloser(bytes.NewReader(challenge))})
    if err != nil {
        return nil, fmt.Errorf("request license: %w", err)
    }
    defer func() { _ = resp.Body.Close() }()

    license, err := io.ReadAll(resp.Body)
    if err != nil {
        return nil, fmt.Errorf("read resp: %w", err)
    }

    // Parse license
    keys, err := parseLicense(license)
    if err != nil {
        return nil, fmt.Errorf("parse license: %w", err)
    }

    return keys, nil
}

func getServiceCert() (*widevinepb.DrmCertificate, error) {
    resp, err := http.DefaultClient.Do(&http.Request{Body: io.NopCloser(bytes.NewReader(widevine.ServiceCertificateRequest))})
    if err != nil {
        return nil, fmt.Errorf("request service cert: %w", err)
    }
    defer func() { _ = resp.Body.Close() }()

    serviceCert, err := io.ReadAll(resp.Body)
    if err != nil {
        return nil, fmt.Errorf("read response: %w", err)
    }

    cert, err := widevine.ParseServiceCert(serviceCert)
    if err != nil {
        return nil, fmt.Errorf("parse service cert: %w", err)
    }

    return cert, nil
}

Thanks

Disclaimer

The project does not provide Google-provisioned private key and client id except for test purpose.
The project does not condone piracy or any action against the terms of the DRM systems.
The project is for study and research only, please do not use it for commercial purposes.

License

GPLv3 License

Gowidevine

Install / Use

README