Class crypto

Example

// Step 1: Generate a state parameter and code verifier for PKCE
const state = crypto.randomUUID();
console.log('OAuth2 State:', state);

const codeVerifierArray = new Uint8Array(32); // Secure random array
crypto.getRandomValues(codeVerifierArray);
const codeVerifier = Array.from(codeVerifierArray).map(b => b.toString(16).padStart(2, '0')).join('');
console.log('Code Verifier:', codeVerifier);

// Step 2: Create a code challenge from the code verifier (SHA-256 hash, Base64-URL encoded)
const encoder = new TextEncoder();
const data = encoder.encode(codeVerifier);

try {
  const hashArray = await crypto.subtle.digest('SHA-256', data);
  const codeChallenge = btoa(String.fromCharCode.apply(null, hashArray))
                          .replace(/\+/g, '-').replace(///g, '_').replace(/=+$/, '');
  console.log('Code Challenge:', codeChallenge);

  // Mock Authorization URL for User to Consent
  const authUrl = `https://authorization.server/auth?response_type=code&client_id=YOUR_CLIENT_ID&scope=YOUR_SCOPES&state=${state}&code_challenge=${codeChallenge}&code_challenge_method=S256`;
  console.log('Authorization URL:', authUrl);

  // Note: The user is redirected to the `authUrl` to authorize and generate an authorization code.

  // Step 3: Assume the authorization server redirects back with a code
  const authorizationCode = 'example_auth_code'; // Placeholder for authorization server response

  // Step 4: Exchange authorization code for access token
  const tokenRequestBody = {
    grant_type: 'authorization_code',
    code: authorizationCode,
    redirect_uri: 'https://your.redirection.uri/callback',
    client_id: 'YOUR_CLIENT_ID',
    code_verifier: codeVerifier,
  };

  // Mock token exchange request (simulate HTTP request)
  // In practice, you would send a POST request to the token endpoint
  console.log('Token Request Body:', JSON.stringify(tokenRequestBody, null, 2));

} catch (error) {
  console.error('Error during OAuth2 flow:', error);
}
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