Sure, you can use the OpenID Connect (OIDC) method for Google login with Ory Kratos. Here's a high-level overview of the process: 1. Initialization: The client (for example, your mobile application) makes a request to the flow's initialization endpoint (for example,

/self-service/login/api

). This endpoint creates a flow object and stores it in the database. The flow object has an ID and contains additional information about the flow such as the login methods and their form data.

bash curl -s -X GET \       -H "Accept: application/json"  \       <https://playground.projects.oryapis.com/self-service/login/api> | jq

2. Login with OIDC: The user needs to go through an OAuth 2.0 or OpenID Connect flow which involves logging into the upstream identity provider (such as Google) and giving consent. If the user has never signed in with the given provider before, a new account will be created. It's also possible to link upstream identities (such as Google profile) with an existing Ory Identities identity. Please note that using API flows in Single-Page-Apps as well as server-side apps opens up several potential attack vectors, including Login and other CSRF attacks. Therefore, it's recommended to use API flows for clients without browsers. For more detailed instructions, please refer to the [Ory Kratos documentation](https://www.ory.sh/docs/kratos/self-service/flows/user-login#login-with-google-facebook-github--openid-connect--oauth-20-1).

Sure, I can explain the flow for you. Here's a high-level overview of the process: 1. Get the User's Permission: The user clicks on a link or button on a web page that requests access to a resource. The requesting application sends a request to the Authorization Server with certain parameters like

response_type

,

client_id

,

redirect_uri

,

state

,

prompt

,

scope

,

max_age

etc. The

redirect_uri

needs to be pre-registered with the OAuth2 client. The

state

parameter is a random value that is generated by the requesting application to prevent cross-site request forgery (CSRF) attacks. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-1-get-the-users-permission) 2. Redirect to the Authorization Server: The user is redirected to the Authorization Server, where they authenticate themselves and grant permission to the requesting application. The Authorization Server could ask the user to log in or prompt them to authorize the access request. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-2-redirect-to-the-authorization-server) 3. Redirect Back to the App: If the user grants permission, the Authorization Server generates an authorization code and redirects the user back to the requesting application with the authorization code. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-3-redirect-back-to-the-app) 4. Exchange Code for Token: The requesting application exchanges the authorization code for an access token that can be used to access the protected resource. The requesting application sends a POST request to the Authorization Server with parameters like

grant_type

,

client_id

,

client_secret

,

code

,

redirect_uri

. The Authorization Server validates the request and responds with an access token and a refresh token (if enabled). The requesting application can use the access token to access the protected resource. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-4-exchange-code-for-token) Here's an example of how you can exchange the authorization code for an access token:

javascript const code = "authorization_code_received_from_auth_server"   const tokenUrl = "https://$<http://PROJECT_SLUG.projects.oryapis.com/oauth2/token|PROJECT_SLUG.projects.oryapis.com/oauth2/token>"   const requestBody = `grant_type=authorization_code&client_id=${clientId}&code_verifier=${codeVerifier}&code=${code}`      fetch(tokenUrl, {     method: "POST",     headers: { "Content-Type": "application/x-www-form-urlencoded" },     body: requestBody,   })     .then((response) => response.json())     .then((data) => console.log(data))     .catch((error) => console.error(error))

[source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#exchange-code-for-token-1) Please note that the actual implementation may vary depending on your specific use case and the OAuth2 client you are using.

The

code_verifier

is a cryptographically random string generated by the client, which is hashed (transformed) into the

code_challenge

. This is part of the Proof Key for Code Exchange (PKCE) extension to the OAuth2 protocol, which is used to secure OAuth2 in public clients. When the client initiates the authorization request, it sends the

code_challenge

to the Authorization Server. Later, when the client exchanges the authorization code for an access token, it sends the

code_verifier

. The Authorization Server hashes the

code_verifier

and ensures that it matches the

code_challenge

it received earlier. This confirms that the client exchanging the authorization code is the same as the client that initiated the authorization request. Here's an example of how to generate a

code_verifier

and `code_challenge`:

javascript // Generate PKCE code challenge and verifier   async function generatePKCES256() {     const array = new Uint8Array(64)     crypto.getRandomValues(array)     const codeVerifier = Buffer.from(array).toString("base64").replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_")        const codeChallenge = await crypto.subtle.digest("SHA-256", new TextEncoder().encode(verifier)).then((buffer) => {       return Buffer.from(buffer).toString("base64").replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_")     })        return { codeChallenge, codeVerifier }   }

[source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#perform-pkce)

To generate the Google authentication URL, you need to pass several parameters. Here's a general outline: 1. Client ID: This is the ID of your application that you received from the Google Developer Console when you registered your application. 2. Redirect URI: This is the URL where Google will redirect the user after they grant permission. This URL needs to be pre-registered with Google when you set up your application. 3. Response Type: This should be set to

code

to indicate that the Authorization Code flow will be used. 4. Scope: This specifies what resources your application can access. For Google, this could be something like

profile email

. 5. State: This is a random value generated by your application to prevent cross-site request forgery (CSRF) attacks. 6. Prompt: This parameter specifies whether the Authorization Server prompts the user for reauthentication and consent. Here's an example of how you might construct the Google authentication URL:

javascript const clientId = "your_client_id"; const redirectUri = encodeURIComponent("your_redirect_uri"); const responseType = "code"; const scope = encodeURIComponent("profile email"); const state = "random_state_value"; const prompt = "select_account";  const authUrl = `<https://accounts.google.com/o/oauth2/v2/auth?client_id=${clientId}&redirect_uri=${redirectUri}&response_type=${responseType}&scope=${scope}&state=${state}&prompt=${prompt}`;>  console.log(authUrl);

Please replace

"your_client_id"

and

"your_redirect_uri"

with your actual client ID and redirect URI. Remember, the actual implementation may vary depending on your specific use case and the OAuth2 client you are using. For more detailed instructions, please refer to the [Google OAuth2 documentation](https://developers.google.com/identity/protocols/oauth2) and the [Ory documentation](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-1-get-the-users-permission).

No, when you're constructing the Google authentication URL, you don't need to include the

flow_id

from Kratos. The

flow_id

is used in the context of Ory Kratos' self-service flows, such as login, registration, or settings, and it's used to fetch the flow's data or to submit data to the flow. The Google authentication URL is part of the OAuth2 Authorization Code flow, which is a separate process. After the user authenticates with Google and grants your application access, Google will redirect the user back to your application with an authorization code. You can then exchange this code for an access token and use the token to access Google APIs on behalf of the user. However, once you receive the token from Google, you would then use this token to complete the Ory Kratos login flow. This would involve submitting the token to the Kratos login flow endpoint, which would require the

flow_id

. For more information, please refer to the [Ory Kratos documentation](https://www.ory.sh/docs/kratos/self-service/flows/user-login#login-with-google-facebook-github--openid-connect--oauth-20-1) and the [Google OAuth2 documentation](https://developers.google.com/identity/protocols/oauth2).

The error message "404 page not found" typically means that the server could not find the requested URL. In this case, it seems like the URL you're trying to access (`http://localhost:4433/oauth2/auth`) might not be correct or the server at

localhost:4433

is not running. Here are a few things you can check: 1. Server Status: Make sure that your Ory Hydra server is running and listening on port 4433. 2. URL Format: Ensure that the URL is correctly formatted. The URL you provided seems to have some placeholders (

<Client_iD>

and `<http://localhost:3000/auth/google-login-callback`). You should replace these with your actual client ID and redirect URI. 3. Client Configuration: Make sure that the client ID you're using is correct and that the redirect URI you're using is registered with your OAuth2 client. Here's how the corrected URL might look:

javascript const clientId = "your_actual_client_id"; const redirectUri = encodeURIComponent("<http://localhost:3000/auth/google-login-callback>"); const authorizationUrl = `<http://localhost:4433/oauth2/auth?response_type=code&client_id=${clientId}&redirect_uri=${redirectUri}&scope=openid%20offline_access&state=12345`;>  // Redirect the user to the Authorization Server to start the authorization flow window.location = authorizationUrl;

Please replace

"your_actual_client_id"

with your actual client ID. If you're still having trouble, you might find it helpful to review the [Ory Hydra documentation](https://www.ory.sh/docs/hydra/5min-tutorial) and the [Ory OAuth2 & OpenID Connect documentation](https://www.ory.sh/docs/getting-started/oauth2-openid/add-oauth2-openid-connect-nodejs-expressjs#prerequisites).

Ory Kratos and Ory Hydra serve different purposes and are used for different aspects of authentication and authorization. Ory Kratos is an identity management server. It handles tasks like registration, login, account recovery, and account verification. It provides the functionality for managing user identities in your application. [source](https://www.ory.sh/docs/ecosystem/projects) Ory Hydra on the other hand, is an OAuth 2.0 and OpenID Connect provider. It doesn't handle user management, but instead connects to your existing user management system (like Ory Kratos or your own custom user system). It's responsible for issuing access, refresh, and ID tokens in a secure and OpenID Certified manner. [source](https://www.ory.sh/docs/ecosystem/projects#ory-hydra) So, if you're only using Ory Kratos, you're handling user management but not necessarily the delegation of permissions and authorization, which is where Ory Hydra comes in. If your application needs to support OAuth2 or OpenID Connect protocols, for example, to allow third-party applications to access your APIs on behalf of users, then you would need Ory Hydra. However, if your application doesn't require these features, and you're only interested in managing user identities, then using Ory Kratos alone might be sufficient for your needs.

You're correct. The page you're referring to explains the general process of the OAuth2 Authorization Code Flow, which is a standard protocol used in many different contexts, not just with Ory Hydra. This flow is used to obtain both access tokens and refresh tokens and is suitable for clients that can securely maintain a client secret between themselves and the Authorization Server. Here's a brief summary of the steps involved in the Authorization Code Flow: 1. Get the User's Permission: The user clicks on a link or button on a web page that requests access to a resource. The requesting application sends a request to the Authorization Server with certain parameters like

response_type

,

client_id

,

redirect_uri

,

state

,

prompt

,

scope

,

max_age

etc. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-1-get-the-users-permission) 2. Redirect to the Authorization Server: The user is redirected to the Authorization Server, where they authenticate themselves and grant permission to the requesting application. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-2-redirect-to-the-authorization-server) 3. Redirect Back to the App: If the user grants permission, the Authorization Server generates an authorization code and redirects the user back to the requesting application with the authorization code. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-3-redirect-back-to-the-app) 4. Exchange Code for Token: The requesting application exchanges the authorization code for an access token that can be used to access the protected resource. [source](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-4-exchange-code-for-token) While Ory Hydra is not specifically mentioned in these steps, it can act as the Authorization Server in this flow. If you're using Ory Hydra, it would be responsible for managing and issuing the authorization codes and access tokens as described in these steps.

Based on the information provided, it's difficult to pinpoint the exact cause of the "404 page not found" error you're encountering. However, here are a few common issues that could lead to this error: 1. Incorrect URL: Ensure that the URL you're trying to access is correct. The URL should match the endpoint specified in the Ory Kratos API documentation. 2. Server not running: Make sure that your Ory Kratos server is running and accessible. If the server is not running or if there's a network issue, you might see a "404 page not found" error. 3. Incorrect API route: Make sure you're using the correct API route for the operation you're trying to perform. For example, if you're trying to initiate a login flow, the correct route would be

/self-service/login/browser

. 4. Missing or incorrect parameters: Some API routes require specific parameters. Make sure you're providing all required parameters and that they are correct. Without more specific information about the API call you're trying to make, it's difficult to provide a more precise answer. I would recommend checking the [Ory Kratos API documentation](https://www.ory.sh/docs/kratos/reference/api) to ensure you're using the correct API route and parameters. If you're still having trouble, you might find it helpful to provide more details about the API call you're trying to make.