🔐 git-oidc

TL;DR

• Rust library for validating GitHub OIDC tokens
• Fetches JWKS and verifies token claims for GitHub Actions
• No more long-lived credentials in your repository

🚀 Installation

cargo add git-oidc

🤔 Use Case Scenario

git-oidc enables secure, credential-free authentication for custom GitHub integrations:

1. Set up a custom OIDC provider service (e.g., railway.app).
2. GitHub Actions generates an OIDC token for your Github Actions.
3. Your custom OIDC provider service uses git-oidc to validate the token.
4. Validation can be used for any Github Actions workflow

⚙️ Usage

Example Rust Service

use actix_web::{web, App, HttpResponse, HttpServer, Responder};
use git_oidc::{fetch_jwks, validate_github_token};

async fn custom_endpoint(
    token_request: web::Json<TokenRequest>,
    data: web::Data<AppState>,
) -> impl Responder {
    match validate_github_token(&token_request.token, data.jwks.clone(), "https://github.com/your-username").await {
        Ok(claims) => {
            info!("Token validated successfully");
            HttpResponse::Ok().json(claims)
        }
        Err(e) => {
            error!("Token validation error: {:?}", e);
            HttpResponse::BadRequest().body(format!("Invalid token: {}", e))
        }
    }
}    

#[actix_web::main]
async fn main() -> Result<()> {
    env_logger::init_from_env(Env::default().default_filter_or("debug"));
    color_eyre::install()?;

    let github_oidc_url = "https://token.actions.githubusercontent.com";
    let jwks = Arc::new(RwLock::new(fetch_jwks(github_oidc_url).await?));

    HttpServer::new(move || {
        App::new()
            .app_data(web::Data::new(AppState { jwks: jwks.clone() }))
            .route("/token", web::post().to(custom_endpoint))
    })
    .bind("0.0.0.0:3000")?
    .run()
    .await?;

    Ok(())
}

Example GitHub Actions Workflow that uses OIDC URL Server

name: Get and Validate JWT

on:
  workflow_dispatch:

jobs:
  get_and_validate_jwt:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: read
    steps:
      - name: Get JWT
        id: get_token
        uses: actions/github-script@v6
        with:
          script: |
            const token = await core.getIDToken()
            core.setOutput('token', token)

      - name: Validate JWT
        env:
          OIDC_SERVICE_URL: ${{ secrets.OIDC_SERVICE_URL }}
        run: |
          TOKEN="${{ steps.get_token.outputs.token }}"
          RESPONSE=$(curl -s -X POST $OIDC_SERVICE_URL \
            -H "Content-Type: application/json" \
            -d "{\"token\": \"$TOKEN\"}")
          echo "OIDC Service Response: $RESPONSE"
          
          if [[ $RESPONSE == *"Invalid token"* ]]; then
            echo "::error::Token validation failed: $RESPONSE"
            exit 1
          elif [[ $RESPONSE == *"error"* ]]; then
            echo "::warning::Unexpected error occurred: $RESPONSE"
            exit 1
          elif [[ -z "$RESPONSE" ]]; then
            echo "::error::Empty response from OIDC service"
            exit 1
          else
            echo "::notice::Token validated successfully"
            echo "$RESPONSE" | jq .
          fi