🔐 Middleware for keeping track of users, login states and permissions
Go

README.md

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Middleware for keeping track of users, login states and permissions.

Online API Documentation

godoc.org

Features and limitations

  • Uses secure cookies and stores user information in a Redis database.
  • Suitable for running a local Redis server, registering/confirming users and managing public/user/admin pages.
  • Also supports connecting to remote Redis servers.
  • Does not support SQL databases. For MariaDB/MySQL support, look into permissionsql.
  • For Bolt database support (no database host needed, uses a file), look into permissionbolt.
  • Supports registration and confirmation via generated confirmation codes.
  • Tries to keep things simple.
  • Only supports public, user and admin permissions out of the box, but offers functionality for implementing more fine grained permissions, if so desired.
  • The default permissions can be cleared with the Clear() function.
  • Supports Negroni, Martini, Gin, Macaron, Goji and plain net/http.
  • Should also work with other frameworks, since the standard http.HandlerFunc is used everywhere.

Example for Negroni

package main

import (
    "fmt"
    "net/http"
    "strings"
    "log"

    "github.com/codegangsta/negroni"
    "github.com/xyproto/permissions2"
)

func main() {
    n := negroni.Classic()
    mux := http.NewServeMux()

    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "Has user bob: %v\n", userstate.HasUser("bob"))
        fmt.Fprintf(w, "Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        fmt.Fprintf(w, "Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        fmt.Fprintf(w, "Username stored in cookies (or blank): %v\n", userstate.Username(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(req))
        fmt.Fprintf(w, "\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
    })

    mux.HandleFunc("/register", func(w http.ResponseWriter, req *http.Request) {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        fmt.Fprintf(w, "User bob was created: %v\n", userstate.HasUser("bob"))
    })

    mux.HandleFunc("/confirm", func(w http.ResponseWriter, req *http.Request) {
        userstate.MarkConfirmed("bob")
        fmt.Fprintf(w, "User bob was confirmed: %v\n", userstate.IsConfirmed("bob"))
    })

    mux.HandleFunc("/remove", func(w http.ResponseWriter, req *http.Request) {
        userstate.RemoveUser("bob")
        fmt.Fprintf(w, "User bob was removed: %v\n", !userstate.HasUser("bob"))
    })

    mux.HandleFunc("/login", func(w http.ResponseWriter, req *http.Request) {
        userstate.Login(w, "bob")
        fmt.Fprintf(w, "bob is now logged in: %v\n", userstate.IsLoggedIn("bob"))
    })

    mux.HandleFunc("/logout", func(w http.ResponseWriter, req *http.Request) {
        userstate.Logout("bob")
        fmt.Fprintf(w, "bob is now logged out: %v\n", !userstate.IsLoggedIn("bob"))
    })

    mux.HandleFunc("/makeadmin", func(w http.ResponseWriter, req *http.Request) {
        userstate.SetAdminStatus("bob")
        fmt.Fprintf(w, "bob is now administrator: %v\n", userstate.IsAdmin("bob"))
    })

    mux.HandleFunc("/clear", func(w http.ResponseWriter, req *http.Request) {
        userstate.ClearCookie(w)
        fmt.Fprintf(w, "Clearing cookie")
    })

    mux.HandleFunc("/data", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "user page that only logged in users must see!")
    })

    mux.HandleFunc("/admin", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            fmt.Fprintf(w, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Custom handler for when permissions are denied
    perm.SetDenyFunction(func(w http.ResponseWriter, req *http.Request) {
        http.Error(w, "Permission denied!", http.StatusForbidden)
    })

    // Enable the permissions middleware
    n.Use(perm)

    // Use mux for routing, this goes last
    n.UseHandler(mux)

    // Serve
    n.Run(":3000")
}

Example for Martini

package main

import (
    "fmt"
    "net/http"
    "strings"
    "log"

    "github.com/go-martini/martini"
    "github.com/xyproto/permissions2"
)

func main() {
    m := martini.Classic()

    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    m.Get("/", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "Has user bob: %v\n", userstate.HasUser("bob"))
        fmt.Fprintf(w, "Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        fmt.Fprintf(w, "Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        fmt.Fprintf(w, "Username stored in cookies (or blank): %v\n", userstate.Username(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(req))
        fmt.Fprintf(w, "\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
    })

    m.Get("/register", func(w http.ResponseWriter) {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        fmt.Fprintf(w, "User bob was created: %v\n", userstate.HasUser("bob"))
    })

    m.Get("/confirm", func(w http.ResponseWriter) {
        userstate.MarkConfirmed("bob")
        fmt.Fprintf(w, "User bob was confirmed: %v\n", userstate.IsConfirmed("bob"))
    })

    m.Get("/remove", func(w http.ResponseWriter) {
        userstate.RemoveUser("bob")
        fmt.Fprintf(w, "User bob was removed: %v\n", !userstate.HasUser("bob"))
    })

    m.Get("/login", func(w http.ResponseWriter) {
        userstate.Login(w, "bob")
        fmt.Fprintf(w, "bob is now logged in: %v\n", userstate.IsLoggedIn("bob"))
    })

    m.Get("/logout", func(w http.ResponseWriter) {
        userstate.Logout("bob")
        fmt.Fprintf(w, "bob is now logged out: %v\n", !userstate.IsLoggedIn("bob"))
    })

    m.Get("/makeadmin", func(w http.ResponseWriter) {
        userstate.SetAdminStatus("bob")
        fmt.Fprintf(w, "bob is now administrator: %v\n", userstate.IsAdmin("bob"))
    })

    m.Get("/clear", func(w http.ResponseWriter) {
        userstate.ClearCookie(w)
        fmt.Fprintf(w, "Clearing cookie")
    })

    m.Get("/data", func(w http.ResponseWriter) {
        fmt.Fprintf(w, "user page that only logged in users must see!")
    })

    m.Get("/admin", func(w http.ResponseWriter) {
        fmt.Fprintf(w, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            fmt.Fprintf(w, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Set up a middleware handler for Martini, with a custom "permission denied" message.
    permissionHandler := func(w http.ResponseWriter, req *http.Request, c martini.Context) {
        // Check if the user has the right admin/user rights
        if perm.Rejected(w, req) {
            // Deny the request
            http.Error(w, "Permission denied!", http.StatusForbidden)
            // Reject the request by not calling the next handler below
            return
        }
        // Call the next middleware handler
        c.Next()
    }

    // Enable the permissions middleware
    m.Use(permissionHandler)

    // Serve
    m.Run()
}

Example for Gin

package main

import (
    "fmt"
    "net/http"
    "strings"
    "log"

    "github.com/gin-gonic/gin"
    "github.com/xyproto/permissions2"
)

func main() {
    g := gin.New()

    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Set up a middleware handler for Gin, with a custom "permission denied" message.
    permissionHandler := func(c *gin.Context) {
        // Check if the user has the right admin/user rights
        if perm.Rejected(c.Writer, c.Request) {
            // Deny the request, don't call other middleware handlers
            c.AbortWithStatus(http.StatusForbidden)
            fmt.Fprint(c.Writer, "Permission denied!")
            return
        }
        // Call the next middleware handler
        c.Next()
    }

    // Logging middleware
    g.Use(gin.Logger())

    // Enable the permissions middleware, must come before recovery
    g.Use(permissionHandler)

    // Recovery middleware
    g.Use(gin.Recovery())

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    g.GET("/", func(c *gin.Context) {
        msg := ""
        msg += fmt.Sprintf("Has user bob: %v\n", userstate.HasUser("bob"))
        msg += fmt.Sprintf("Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        msg += fmt.Sprintf("Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        msg += fmt.Sprintf("Username stored in cookies (or blank): %v\n", userstate.Username(c.Request))
        msg += fmt.Sprintf("Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(c.Request))
        msg += fmt.Sprintf("Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(c.Request))
        msg += fmt.Sprintln("\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
        c.String(http.StatusOK, msg)
    })

    g.GET("/register", func(c *gin.Context) {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        c.String(http.StatusOK, fmt.Sprintf("User bob was created: %v\n", userstate.HasUser("bob")))
    })

    g.GET("/confirm", func(c *gin.Context) {
        userstate.MarkConfirmed("bob")
        c.String(http.StatusOK, fmt.Sprintf("User bob was confirmed: %v\n", userstate.IsConfirmed("bob")))
    })

    g.GET("/remove", func(c *gin.Context) {
        userstate.RemoveUser("bob")
        c.String(http.StatusOK, fmt.Sprintf("User bob was removed: %v\n", !userstate.HasUser("bob")))
    })

    g.GET("/login", func(c *gin.Context) {
        // Headers will be written, for storing a cookie
        userstate.Login(c.Writer, "bob")
        c.String(http.StatusOK, fmt.Sprintf("bob is now logged in: %v\n", userstate.IsLoggedIn("bob")))
    })

    g.GET("/logout", func(c *gin.Context) {
        userstate.Logout("bob")
        c.String(http.StatusOK, fmt.Sprintf("bob is now logged out: %v\n", !userstate.IsLoggedIn("bob")))
    })

    g.GET("/makeadmin", func(c *gin.Context) {
        userstate.SetAdminStatus("bob")
        c.String(http.StatusOK, fmt.Sprintf("bob is now administrator: %v\n", userstate.IsAdmin("bob")))
    })

    g.GET("/clear", func(c *gin.Context) {
        userstate.ClearCookie(c.Writer)
        c.String(http.StatusOK, "Clearing cookie")
    })

    g.GET("/data", func(c *gin.Context) {
        c.String(http.StatusOK, "user page that only logged in users must see!")
    })

    g.GET("/admin", func(c *gin.Context) {
        c.String(http.StatusOK, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            c.String(http.StatusOK, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Serve
    g.Run(":3000")
}

Example for Macaron

package main

import (
    "fmt"
    "net/http"
    "strings"
    "log"

    "github.com/Unknwon/macaron"
    "github.com/xyproto/permissions2"
)

func main() {
    m := macaron.Classic()

    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Logging middleware
    m.Use(macaron.Logger())

    // Renderer middleware
    m.Use(macaron.Renderer())

    // Set up a middleware handler for Macaron, with a custom "permission denied" message.
    permissionHandler := func(ctx *macaron.Context) {
        // Check if the user has the right admin/user rights
        if perm.Rejected(ctx.Resp, ctx.Req.Request) {
            fmt.Fprintf(ctx.Resp, "Permission denied!")
            // Deny the request
            ctx.Error(http.StatusForbidden)
            // Don't call other middleware handlers
            return
        }
        // Call the next middleware handler
        ctx.Next()
    }

    // Enable the permissions middleware, must come before recovery
    m.Use(permissionHandler)

    // Recovery middleware
    m.Use(macaron.Recovery())

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    m.Get("/", func(ctx *macaron.Context) string {
        msg := ""
        msg += fmt.Sprintf("Has user bob: %v\n", userstate.HasUser("bob"))
        msg += fmt.Sprintf("Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        msg += fmt.Sprintf("Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        msg += fmt.Sprintf("Username stored in cookies (or blank): %v\n", userstate.Username(ctx.Req.Request))
        msg += fmt.Sprintf("Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(ctx.Req.Request))
        msg += fmt.Sprintf("Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(ctx.Req.Request))
        msg += fmt.Sprintln("\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
        return msg
    })

    m.Get("/register", func(ctx *macaron.Context) string {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        return fmt.Sprintf("User bob was created: %v\n", userstate.HasUser("bob"))
    })

    m.Get("/confirm", func(ctx *macaron.Context) string {
        userstate.MarkConfirmed("bob")
        return fmt.Sprintf("User bob was confirmed: %v\n", userstate.IsConfirmed("bob"))
    })

    m.Get("/remove", func(ctx *macaron.Context) string {
        userstate.RemoveUser("bob")
        return fmt.Sprintf("User bob was removed: %v\n", !userstate.HasUser("bob"))
    })

    m.Get("/login", func(ctx *macaron.Context) string {
        // Headers will be written, for storing a cookie
        userstate.Login(ctx.Resp, "bob")
        return fmt.Sprintf("bob is now logged in: %v\n", userstate.IsLoggedIn("bob"))
    })

    m.Get("/logout", func(ctx *macaron.Context) string {
        userstate.Logout("bob")
        return fmt.Sprintf("bob is now logged out: %v\n", !userstate.IsLoggedIn("bob"))
    })

    m.Get("/makeadmin", func(ctx *macaron.Context) string {
        userstate.SetAdminStatus("bob")
        return fmt.Sprintf("bob is now administrator: %v\n", userstate.IsAdmin("bob"))
    })

    m.Get("/clear", func(ctx *macaron.Context) string {
        userstate.ClearCookie(ctx.Resp)
        return "Clearing cookie"
    })

    m.Get("/data", func(ctx *macaron.Context) string {
        return "user page that only logged in users must see!"
    })

    m.Get("/admin", func(ctx *macaron.Context) {
        fmt.Fprintf(ctx.Resp, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            fmt.Fprintf(ctx.Resp, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Serve
    m.Run(3000)
}

Example for Goji

package main

import (
    "fmt"
    "net/http"
    "strings"
    "log"

    "github.com/xyproto/permissions2"
    "github.com/zenazn/goji"
)

func main() {
    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    goji.Get("/", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "Has user bob: %v\n", userstate.HasUser("bob"))
        fmt.Fprintf(w, "Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        fmt.Fprintf(w, "Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        fmt.Fprintf(w, "Username stored in cookies (or blank): %v\n", userstate.Username(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(req))
        fmt.Fprintf(w, "\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
    })

    goji.Get("/register", func(w http.ResponseWriter, req *http.Request) {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        fmt.Fprintf(w, "User bob was created: %v\n", userstate.HasUser("bob"))
    })

    goji.Get("/confirm", func(w http.ResponseWriter, req *http.Request) {
        userstate.MarkConfirmed("bob")
        fmt.Fprintf(w, "User bob was confirmed: %v\n", userstate.IsConfirmed("bob"))
    })

    goji.Get("/remove", func(w http.ResponseWriter, req *http.Request) {
        userstate.RemoveUser("bob")
        fmt.Fprintf(w, "User bob was removed: %v\n", !userstate.HasUser("bob"))
    })

    goji.Get("/login", func(w http.ResponseWriter, req *http.Request) {
        userstate.Login(w, "bob")
        fmt.Fprintf(w, "bob is now logged in: %v\n", userstate.IsLoggedIn("bob"))
    })

    goji.Get("/logout", func(w http.ResponseWriter, req *http.Request) {
        userstate.Logout("bob")
        fmt.Fprintf(w, "bob is now logged out: %v\n", !userstate.IsLoggedIn("bob"))
    })

    goji.Get("/makeadmin", func(w http.ResponseWriter, req *http.Request) {
        userstate.SetAdminStatus("bob")
        fmt.Fprintf(w, "bob is now administrator: %v\n", userstate.IsAdmin("bob"))
    })

    goji.Get("/clear", func(w http.ResponseWriter, req *http.Request) {
        userstate.ClearCookie(w)
        fmt.Fprintf(w, "Clearing cookie")
    })

    goji.Get("/data", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "user page that only logged in users must see!")
    })

    goji.Get("/admin", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            fmt.Fprintf(w, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Custom "permissions denied" message
    perm.SetDenyFunction(func(w http.ResponseWriter, req *http.Request) {
        http.Error(w, "Permission denied!", http.StatusForbidden)
    })

    // Permissions middleware for Goji
    permissionHandler := func(next http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
            // Check if the user has the right admin/user rights
            if perm.Rejected(w, req) {
                // Deny the request
                perm.DenyFunction()(w, req)
                return
            }
            // Serve the requested page
            next.ServeHTTP(w, req)
        })
    }

    // Enable the permissions middleware
    goji.Use(permissionHandler)

    // Goji will listen to port 8000 by default
    goji.Serve()
}

Example for just net/http

package main

import (
    "fmt"
    "log"
    "net/http"
    "strings"
    "time"

    "github.com/xyproto/permissions2"
    "github.com/xyproto/pinterface"
)

type permissionHandler struct {
    // perm is a Permissions structure that can be used to deny requests
    // and acquire the UserState. By using `pinterface.IPermissions` instead
    // of `*permissions.Permissions`, the code is compatible with not only
    // `permissions2`, but also other modules that uses other database
    // backends, like `permissionbolt` which uses Bolt.
    perm pinterface.IPermissions

    // The HTTP multiplexer
    mux *http.ServeMux
}

// Implement the ServeHTTP method to make a permissionHandler a http.Handler
func (ph *permissionHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    // Check if the user has the right admin/user rights
    if ph.perm.Rejected(w, req) {
        // Let the user know, by calling the custom "permission denied" function
        ph.perm.DenyFunction()(w, req)
        // Reject the request
        return
    }
    // Serve the requested page if permissions were granted
    ph.mux.ServeHTTP(w, req)
}

func main() {
    mux := http.NewServeMux()

    // New permissions middleware
    perm, err := permissions.New2()
    if err != nil {
        log.Fatalln(err)
    }

    // Blank slate, no default permissions
    //perm.Clear()

    // Get the userstate, used in the handlers below
    userstate := perm.UserState()

    mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "Has user bob: %v\n", userstate.HasUser("bob"))
        fmt.Fprintf(w, "Logged in on server: %v\n", userstate.IsLoggedIn("bob"))
        fmt.Fprintf(w, "Is confirmed: %v\n", userstate.IsConfirmed("bob"))
        fmt.Fprintf(w, "Username stored in cookies (or blank): %v\n", userstate.Username(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *user rights*: %v\n", userstate.UserRights(req))
        fmt.Fprintf(w, "Current user is logged in, has a valid cookie and *admin rights*: %v\n", userstate.AdminRights(req))
        fmt.Fprintf(w, "\nTry: /register, /confirm, /remove, /login, /logout, /makeadmin, /clear, /data and /admin")
    })

    mux.HandleFunc("/register", func(w http.ResponseWriter, req *http.Request) {
        userstate.AddUser("bob", "hunter1", "bob@zombo.com")
        fmt.Fprintf(w, "User bob was created: %v\n", userstate.HasUser("bob"))
    })

    mux.HandleFunc("/confirm", func(w http.ResponseWriter, req *http.Request) {
        userstate.MarkConfirmed("bob")
        fmt.Fprintf(w, "User bob was confirmed: %v\n", userstate.IsConfirmed("bob"))
    })

    mux.HandleFunc("/remove", func(w http.ResponseWriter, req *http.Request) {
        userstate.RemoveUser("bob")
        fmt.Fprintf(w, "User bob was removed: %v\n", !userstate.HasUser("bob"))
    })

    mux.HandleFunc("/login", func(w http.ResponseWriter, req *http.Request) {
        userstate.Login(w, "bob")
        fmt.Fprintf(w, "bob is now logged in: %v\n", userstate.IsLoggedIn("bob"))
    })

    mux.HandleFunc("/logout", func(w http.ResponseWriter, req *http.Request) {
        userstate.Logout("bob")
        fmt.Fprintf(w, "bob is now logged out: %v\n", !userstate.IsLoggedIn("bob"))
    })

    mux.HandleFunc("/makeadmin", func(w http.ResponseWriter, req *http.Request) {
        userstate.SetAdminStatus("bob")
        fmt.Fprintf(w, "bob is now administrator: %v\n", userstate.IsAdmin("bob"))
    })

    mux.HandleFunc("/clear", func(w http.ResponseWriter, req *http.Request) {
        userstate.ClearCookie(w)
        fmt.Fprintf(w, "Clearing cookie")
    })

    mux.HandleFunc("/data", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "user page that only logged in users must see!")
    })

    mux.HandleFunc("/admin", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "super secret information that only logged in administrators must see!\n\n")
        if usernames, err := userstate.AllUsernames(); err == nil {
            fmt.Fprintf(w, "list of all users: "+strings.Join(usernames, ", "))
        }
    })

    // Custom handler for when permissions are denied
    perm.SetDenyFunction(func(w http.ResponseWriter, req *http.Request) {
        http.Error(w, "Permission denied!", http.StatusForbidden)
    })

    // Configure the HTTP server and permissionHandler struct
    s := &http.Server{
        Addr:           ":3000",
        Handler:        &permissionHandler{perm, mux},
        ReadTimeout:    10 * time.Second,
        WriteTimeout:   10 * time.Second,
        MaxHeaderBytes: 1 << 20,
    }

    log.Println("Listening for requests on port 3000")

    // Start listening
    s.ListenAndServe()
}

Default permissions

  • The /admin path prefix has admin rights by default.
  • These path prefixes have user rights by default: /repo and /data
  • These path prefixes are public by default: /, /login, /register, /style, /img, /js, /favicon.ico, /robots.txt and /sitemap_index.xml

The default permissions can be cleared with the Clear() function.

Password hashing

  • bcrypt is used by default for hashing passwords. sha256 is also supported.
  • By default, all new password will be hashed with bcrypt.
  • For backwards compatibility, old password hashes with the length of a sha256 hash will be checked with sha256. To disable this behavior, and only ever use bcrypt, add this line: userstate.SetPasswordAlgo("bcrypt")

Passing userstate to functions

One way of passing a userstate to a function is to use the pinterface package, like in this source file (using perm pinterface.IPermissions as the argument). Another method is to use a closure, as in the examples above.

Coding style

  • The code shall always be formatted with go fmt.

Setting and getting properties for users

  • Setting a property:
username := "bob"
propertyName := "clever"
propertyValue := "yes"

userstate.Users().Set(username, propertyName, propertyValue)
  • Getting a property:
username := "bob"
propertyName := "clever"
propertyValue, err := userstate.Users().Get(username, propertyName)
if err != nil {
    log.Print(err)
    return err
}
fmt.Printf("%s is %s: %s\n", username, propertyName, propertyValue)

General information

  • Version: 2.2
  • License: MIT
  • Alexander F Rødseth