Facebook Login API

Package cognitoidentity provides the API client, operations, and parameter types for Amazon Cognito Identity. Amazon Cognito Federated Identities is a web service that delivers scoped temporary credentials to mobile devices and other untrusted environments. It uniquely identifies a device and supplies the user with a consistent identity over the lifetime of an application. Using Amazon Cognito Federated Identities, you can enable authentication with one or more third-party identity providers (Facebook, Google, or Login with Amazon) or an Amazon Cognito user pool, and you can also choose to support unauthenticated access from your app. Cognito delivers a unique identifier for each user and acts as an OpenID token provider trusted by AWS Security Token Service (STS) to access temporary, limited-privilege AWS credentials. For a description of the authentication flow from the Amazon Cognito Developer Guide see Authentication Flow. For more information see Amazon Cognito Federated Identities.

Package fbmsgr provides an API for interacting with Facebook Messenger. The first step is to create a new Messenger session. Do this as follows, replacing "USER" and "PASS" with your Facebook login credentials: Once you are done with a session you have allocated, you should call Close() on it to clear any resources (e.g. goroutines) that it is using. When sending a message, you specify a receiver by their FBID. The receiver may be another user, or it may be a group. For most methods related to message sending, there is one version of the method for a user and one for a group: To send or retract a typing notification, you might do: To send an attachment such as an image or a video, you can do the following: It is easy to receive events such as incoming messages using the ReadEvent method: With the EventStream API, you can get more fine-grained control over how you receive events. For example, you can read the next minute's worth of events like so: You can also create multiple EventStreams and read from different streams in different places. To list the threads (conversations) a user is in, you can use the Threads method to fetch a subset of threads at a time. You can also use the AllThreads method to fetch all the threads at once.

Package fbmsgr provides an API for interacting with Facebook Messenger. The first step is to create a new Messenger session. Do this as follows, replacing "USER" and "PASS" with your Facebook login credentials: Once you are done with a session you have allocated, you should call Close() on it to clear any resources (e.g. goroutines) that it is using. When sending a message, you specify a receiver by their FBID. The receiver may be another user, or it may be a group. For most methods related to message sending, there is one version of the method for a user and one for a group: To send or retract a typing notification, you might do: To send an attachment such as an image or a video, you can do the following: It is easy to receive events such as incoming messages using the ReadEvent method: With the EventStream API, you can get more fine-grained control over how you receive events. For example, you can read the next minute's worth of events like so: You can also create multiple EventStreams and read from different streams in different places. To list the threads (conversations) a user is in, you can use the Threads method to fetch a subset of threads at a time. You can also use the AllThreads method to fetch all the threads at once.

Package Authaus is an authentication and authorization system. Authaus brings together the following pluggable components: Any of these five components can be swapped out, and in fact the fourth, and fifth ones (Role Groups and User Store) are entirely optional. A typical setup is to use LDAP as an Authenticator, and Postgres as a Session, Permit, and Role Groups database. Your session database does not need to be particularly performant, since Authaus maintains an in-process cache of session keys and their associated tokens. Authaus was NOT designed to be a "Facebook Scale" system. The target audience is a system of perhaps 100,000 users. There is nothing fundamentally limiting about the API of Authaus, but the internals certainly have not been built with millions of users in mind. The intended usage model is this: Authaus is intended to be embedded inside your security system, and run as a standalone HTTP service (aka a REST service). This HTTP service CAN be open to the wide world, but it's also completely OK to let it listen only to servers inside your DMZ. Authaus only gives you the skeleton and some examples of HTTP responders. It's up to you to flesh out the details of your authentication HTTP interface, and whether you'd like that to face the world, or whether it should only be accessible via other services that you control. At startup, your services open an HTTP connection to the Authaus service. This connection will typically live for the duration of the service. For every incoming request, you peel off whatever authentication information is associated with that request. This is either a session key, or a username/password combination. Let's call it the authorization information. You then ask Authaus to tell you WHO this authorization information belongs to, as well as WHAT this authorization information allows the requester to do (ie Authentication and Authorization). Authaus responds either with a 401 (Unauthorized), 403 (Forbidden), or a 200 (OK) and a JSON object that tells you the identity of the agent submitting this request, as well the permissions that this agent posesses. It's up to your individual services to decide what to do with that information. It should be very easy to expose Authaus over a protocol other than HTTP, since Authaus is intended to be easy to embed. The HTTP API is merely an illustrative example. A `Session Key` is the long random number that is typically stored as a cookie. A `Permit` is a set of roles that has been granted to a user. Authaus knows nothing about the contents of a permit. It simply treats it as a binary blob, and when writing it to an SQL database, encodes it as base64. The interpretation of the permit is application dependent. Typically, a Permit will hold information such as "Allowed to view billing information", or "Allowed to paint your bathroom yellow". Authaus does have a built-in module called RoleGroupDB, which has its own interpretation of what a Permit is, but you do not need to use this. A `Token` is the result of a successful authentication. It stores the identity of a user, an expiry date, and a Permit. A token will usually be retrieved by a session key. However, you can also perform a once-off authentication, which also yields you a token, which you will typically throw away when you are finished with it. All public methods of the `Central` object are callable from multiple threads. Reader-Writer locks are used in all of the caching systems. The number of concurrent connections is limited only by the limits of the Go runtime, and the performance limits that are inherent to the simple reader-writer locks used to protect shared state. Authaus must be deployed as a single process (which implies running on a single logical machine). The sole reason why it must run on only one process and not more, is because of the state that lives inside the various Authaus caches. Were it not for these caches, then there would be nothing preventing you from running Authaus on as many machines as necessary. The cached state stored inside the Authaus server is: If you wanted to make Authaus runnable across multiple processes, then you would need to implement a cache invalidation system for these caches. Authaus makes no attempt to mitigate DOS attacks. The most sane approach in this domain seems to be this (http://security.stackexchange.com/questions/12101/prevent-denial-of-service-attacks-against-slow-hashing-functions). The password database (created via NewAuthenticationDB_SQL) stores password hashes using the scrypt key derivation system (http://www.tarsnap.com/scrypt.html). Internally, we store our hash in a format that can later be extended, should we wish to double-hash the passwords, etc. The hash is 65 bytes and looks like this: The first byte of the hash is a version number of the hash. The remaining 64 bytes are the salt and the hash itself. At present, only one version is supported, which is version 1. It consists of 32 bytes of salt, and 32 bytes of scrypt'ed hash, with scrypt parameters N=256 r=8 p=1. Note that the parameter N=256 is quite low, meaning that it is possible to compute this in approximately 1 millisecond (1,000,000 nanoseconds) on a 2009-era Intel Core i7. This is a deliberate tradeoff. On the same CPU, a SHA256 hash takes about 500 nanoseconds to compute, so we are still making it 2000 times harder to brute force the passwords than an equivalent system storing only a SHA256 salted hash. This discussion is only of relevance in the event that the password table is compromised. No cookie signing mechanism is implemented. Cookies are not presently transmitted with Secure:true. This must change. The LDAP Authenticator is extremely simple, and provides only one function: Authenticate a user against an LDAP system (often this means Active Directory, AKA a Windows Domain). It calls the LDAP "Bind" method, and if that succeeds for the given identity/password, then the user is considered authenticated. We take care not to allow an "anonymous bind", which many LDAP servers allow when the password is blank. The Session Database runs on Postgres. It stores a table of sessions, where each row contains the following information: When a permit is altered with Authaus, then all existing sessions have their permits altered transparently. For example, imagine User X is logged in, and his administrator grants him a new permission. User X does not need to log out and log back in again in order for his new permissions to be reflected. His new permissions will be available immediately. Similarly, if a password is changed with Authaus, then all sessions are invalidated. Do take note though, that if a password is changed through an external mechanism (such as with LDAP), then Authaus will have no way of knowing this, and will continue to serve up sessions that were authenticated with the old password. This is a problem that needs addressing. You can limit the number of concurrent sessions per user to 1, by setting MaxActiveSessions.ConfigSessionDB to 1. This setting may only be zero or one. Zero, which is the default, means an unlimited number of concurrent sessions per user. Authaus will always place your Session Database behind its own Session Cache. This session cache is a very simple single-process in-memory cache of recent sessions. The limit on the number of entries in this cache is hard-coded, and that should probably change. The Permit database runs on Postgres. It stores a table of permits, which is simply a 1:1 mapping from Identity -> Permit. The Permit is just an array of bytes, which we store base64 encoded, inside a text field. This part of the system doesn't care how you interpret that blob. The Role Group Database is an entirely optional component of Authaus. The other components of Authaus (Authenticator, PermitDB, SessionDB) do not understand your Permits. To them, a Permit is simply an arbitrary array of bytes. The Role Group Database is a component that adds a specific meaning to a permit blob. Let's see what that specific meaning looks like... The built-in Role Group Database interprets a permit blob as a string of 32-bit integer IDs: These 32-bit integer IDs refer to "role groups" inside a database table. The "role groups" table might look like this: The Role Group IDs use 32-bit indices, because we assume that you are not going to create more than 2^32 different role groups. The worst case we assume here is that of an automated system that creates 100,000 roles per day. Such a system would run for more than 100 years, given a 32-bit ID. These constraints are extraordinary, suggesting that we do not even need 32 bits, but could even get away with just a 16-bit group ID. However, we expect the number of groups to be relatively small. Our aim here, arbitrary though it may be, is to fit the permit and identity into a single ethernet packet, which one can reasonably peg at 1500 bytes. 1500 / 4 = 375. We assume that no sane human administrator will assign 375 security groups to any individual. We expect the number of groups assigned to any individual to be in the range of 1 to 20. This makes 375 a gigantic buffer. OAuth support in Authaus is limited to a very simple scenario: * You wish to allow your users to login using an OAuth service - thereby outsourcing the Authentication to that external service, and using it to populate the email address of your users. OAuth was developed in order to work with Microsoft Azure Active Directory, however it should be fairly easy to extend the code to be able to handle other OAuth providers. Inside the database are two tables related to OAuth: oauthchallenge: The challenge table holds OAuth sessions which have been started, and which are expected to either succeed or fail within the next few minutes. The default timeout for a challenge is 5 minutes. A challenge record is usually created the moment the user clicks on the "Sign in with Microsoft" button on your site, and it tracks that authentication attempt. oauthsession: The session table holds OAuth sessions which have successfully authenticated, and also the token that was retrieved by a successful authorization. If a token has expired, then it is refreshed and updated in-place, inside the oauthsession table. An OAuth login follows this sequence of events: 1. User clicks on a "Signin with X" button on your login page 2. A record is created in the oauthchallenge table, with a unique ID. This ID is a secret known only to the authaus server and the OAuth server. It is used as the `state` parameter in the OAuth login mechanism. 3. The HTTP call which prompts #2 return a redirect URL (eg via an HTTP 302 response), which redirects the user's browser to the OAuth website, so that the user can either grant or refuse access. If the user refuses, or fails to login, then the login sequence ends here. 4. Upon successful authorization with the OAuth system, the OAuth website redirects the user back to your website, to a URL such as example.com/auth/oauth/finish, and you'll typically want Authaus to handle this request directly (via HttpHandlerOAuthFinish). Authaus will extract the secrets from the URL, perform any validations necessary, and then move the record from the oauthchallenge table, into the oauthsession table. While 'moving' the record over, it will also add any additional information that was provided by the successful authentication, such as the token provided by the OAuth provider. 5. Authaus makes an API call to the OAuth system, to retrieve the email address and name of the person that just logged in, using the token just received. 6. If that email address does not exist inside authuserstore, then create a new user record for this identity. 7. Log the user into Authaus, by creating a record inside authsession, for the relevant identity. Inside the authsession table, store a link to the oauthsession record, so that there is a 1:1 link from the authsession table, to the oauthsession table (ie Authaus Session to OAuth Token). 8. Return an Authaus session cookie to the browser, thereby completing the login. Although we only use our OAuth token a single time, during login, to retrieve the user's email address and name, we retain the OAuth token, and so we maintain the ability to make other API calls on behalf of that user. This hasn't proven necessary yet, but it seems like a reasonable bit of future-proofing. See the guidelines at the top of all_test.go for testing instructions.

Package cognitoidentity provides the client and types for making API requests to Amazon Cognito Identity. Amazon Cognito is a web service that delivers scoped temporary credentials to mobile devices and other untrusted environments. Amazon Cognito uniquely identifies a device and supplies the user with a consistent identity over the lifetime of an application. Using Amazon Cognito, you can enable authentication with one or more third-party identity providers (Facebook, Google, or Login with Amazon), and you can also choose to support unauthenticated access from your app. Cognito delivers a unique identifier for each user and acts as an OpenID token provider trusted by AWS Security Token Service (STS) to access temporary, limited-privilege AWS credentials. To provide end-user credentials, first make an unsigned call to GetId. If the end user is authenticated with one of the supported identity providers, set the Logins map with the identity provider token. GetId returns a unique identifier for the user. Next, make an unsigned call to GetCredentialsForIdentity. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. Assuming your identity pool has been configured via the SetIdentityPoolRoles operation, GetCredentialsForIdentity will return AWS credentials for your use. If your pool has not been configured with SetIdentityPoolRoles, or if you want to follow legacy flow, make an unsigned call to GetOpenIdToken, which returns the OpenID token necessary to call STS and retrieve AWS credentials. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. The token returned by GetOpenIdToken can be passed to the STS operation AssumeRoleWithWebIdentity (http://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithWebIdentity.html) to retrieve AWS credentials. If you want to use Amazon Cognito in an Android, iOS, or Unity application, you will probably want to make API calls via the AWS Mobile SDK. To learn more, see the AWS Mobile SDK Developer Guide (http://docs.aws.amazon.com/mobile/index.html). See https://docs.aws.amazon.com/goto/WebAPI/cognito-identity-2014-06-30 for more information on this service. See cognitoidentity package documentation for more information. https://docs.aws.amazon.com/sdk-for-go/api/service/cognitoidentity/ To Amazon Cognito Identity with the SDK use the New function to create a new service client. With that client you can make API requests to the service. These clients are safe to use concurrently. See the SDK's documentation for more information on how to use the SDK. https://docs.aws.amazon.com/sdk-for-go/api/ See aws.Config documentation for more information on configuring SDK clients. https://docs.aws.amazon.com/sdk-for-go/api/aws/#Config See the Amazon Cognito Identity client CognitoIdentity for more information on creating client for this service. https://docs.aws.amazon.com/sdk-for-go/api/service/cognitoidentity/#New

Package fbmsgr provides an API for interacting with Facebook Messenger. The first step is to create a new Messenger session. Do this as follows, replacing "USER" and "PASS" with your Facebook login credentials: Once you are done with a session you have allocated, you should call Close() on it to clear any resources (e.g. goroutines) that it is using. When sending a message, you specify a receiver by their FBID. The receiver may be another user, or it may be a group. For most methods related to message sending, there is one version of the method for a user and one for a group: To send or retract a typing notification, you might do: To send an attachment such as an image or a video, you can do the following: It is easy to receive events such as incoming messages using the ReadEvent method: With the EventStream API, you can get more fine-grained control over how you receive events. For example, you can read the next minute's worth of events like so: You can also create multiple EventStreams and read from different streams in different places. To list the threads (conversations) a user is in, you can use the Threads method to fetch a subset of threads at a time. For example, you can print out the IDs of every thread as follows:

Package cognitoidentity provides the client and types for making API requests to Amazon Cognito Identity. Amazon Cognito is a web service that delivers scoped temporary credentials to mobile devices and other untrusted environments. Amazon Cognito uniquely identifies a device and supplies the user with a consistent identity over the lifetime of an application. Using Amazon Cognito, you can enable authentication with one or more third-party identity providers (Facebook, Google, or Login with Amazon), and you can also choose to support unauthenticated access from your app. Cognito delivers a unique identifier for each user and acts as an OpenID token provider trusted by AWS Security Token Service (STS) to access temporary, limited-privilege AWS credentials. To provide end-user credentials, first make an unsigned call to GetId. If the end user is authenticated with one of the supported identity providers, set the Logins map with the identity provider token. GetId returns a unique identifier for the user. Next, make an unsigned call to GetCredentialsForIdentity. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. Assuming your identity pool has been configured via the SetIdentityPoolRoles operation, GetCredentialsForIdentity will return AWS credentials for your use. If your pool has not been configured with SetIdentityPoolRoles, or if you want to follow legacy flow, make an unsigned call to GetOpenIdToken, which returns the OpenID token necessary to call STS and retrieve AWS credentials. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. The token returned by GetOpenIdToken can be passed to the STS operation AssumeRoleWithWebIdentity (http://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithWebIdentity.html) to retrieve AWS credentials. If you want to use Amazon Cognito in an Android, iOS, or Unity application, you will probably want to make API calls via the AWS Mobile SDK. To learn more, see the AWS Mobile SDK Developer Guide (http://docs.aws.amazon.com/mobile/index.html). See https://docs.aws.amazon.com/goto/WebAPI/cognito-identity-2014-06-30 for more information on this service. See cognitoidentity package documentation for more information. https://docs.aws.amazon.com/sdk-for-go/api/service/cognitoidentity/ To Amazon Cognito Identity with the SDK use the New function to create a new service client. With that client you can make API requests to the service. These clients are safe to use concurrently. See the SDK's documentation for more information on how to use the SDK. https://docs.aws.amazon.com/sdk-for-go/api/ See aws.Config documentation for more information on configuring SDK clients. https://docs.aws.amazon.com/sdk-for-go/api/aws/#Config See the Amazon Cognito Identity client CognitoIdentity for more information on creating client for this service. https://docs.aws.amazon.com/sdk-for-go/api/service/cognitoidentity/#New

Package auth provides a complete user authentication system for Go web applications. Quick Start: Features: 1. Email/Password Authentication 2. OAuth Support 3. SAML Single Sign-On Customizable User Info You can override the GetInfo method to return custom user information: type MyDB struct { *auth.UserDB } type CustomUserInfo struct { UserID int64 `json:"userid"` Email string `json:"email"` Name string `json:"name"` AvatarURL string `json:"avatar_url"` } func (db *MyDB) GetInfo(tx auth.Tx, userid int64, newAccount bool) auth.UserInfo { // Query additional user data from your database var info CustomUserInfo err := tx.(*auth.UserTx).Tx.Get(&info, `SELECT userid, email, name, avatar_url FROM users WHERE userid = ?`, userid) if err != nil { panic(err) } return info } // Use your custom DB: authHandler := auth.New(&MyDB{auth.NewUserDB(db)}, settings) API Endpoints: POST /user/auth - Sign in with email/password: email=user@example.com&password=secret - Sign in with OAuth: method=facebook&token=oauth-token - Sign in with SAML: email=user@company.com&sso=1 POST /user/create - Create account: email=user@example.com&password=secret - Optional signin=0 to create without signing in GET /user/get - Get current user info - Returns 401 if not signed in POST /user/signout - Sign out current user POST /user/update - Update email: email=new@example.com - Update password: password=newpassword POST /user/oauth/add - Add OAuth method: method=facebook&token=oauth-token - Optional update_email=true to update email POST /user/oauth/remove - Remove OAuth method: method=facebook POST /user/forgotpassword - Request password reset: email=user@example.com POST /user/resetpassword - Reset password: token=reset-token&password=newpassword GET /user/saml/metadata - Get SAML service provider metadata POST /user/saml/acs - SAML assertion consumer service endpoint Database Schema: The package automatically creates these tables: - Users: Basic user info and credentials - Sessions: Active login sessions - OAuth: Linked OAuth accounts - PasswordResetTokens: Password reset tokens - AuthSettings: Configuration settings See schema.go for complete table definitions. Security Features: - Passwords hashed with bcrypt - Rate limiting on authentication attempts - CSRF protection - Secure session cookies - SQL injection protection via sqlx Example_saml shows how to register Saml providers and override the GetSamlIdentityProviderForUser method