Encrypt Cookie

Encrypt Cookie is a middleware for Fiber that secures your cookie values through encryption.

note

This middleware encrypts cookie values and not the cookie names.

Signatures

// Intitializes the middleware
func New(config ...Config) fiber.Handler

// GenerateKey returns a random string of 16, 24, or 32 bytes.
// The length of the key determines the AES encryption algorithm used:
// 16 bytes for AES-128, 24 bytes for AES-192, and 32 bytes for AES-256-GCM.
func GenerateKey(length int) string

Examples

To use the Encrypt Cookie middleware, first, import the middleware package as part of the Fiber web framework:

import (
    "github.com/gofiber/fiber/v3"
    "github.com/gofiber/fiber/v3/middleware/encryptcookie"
)

Once you've imported the middleware package, you can use it inside your Fiber app:

// Provide a minimal configuration
app.Use(encryptcookie.New(encryptcookie.Config{
    Key: "secret-thirty-2-character-string",
}))

// Retrieve the encrypted cookie value
app.Get("/", func(c fiber.Ctx) error {
    return c.SendString("value=" + c.Cookies("test"))
})

// Create an encrypted cookie
app.Post("/", func(c fiber.Ctx) error {
    c.Cookie(&fiber.Cookie{
        Name:  "test",
        Value: "SomeThing",
    })
    return nil
})

note

The Key parameter requires an encoded string of 16, 24, or 32 bytes for encryption, corresponding to AES-128, AES-192, and AES-256-GCM standards, respectively. Ensure the key is randomly generated and securely stored. To generate a 32 char key, use openssl rand -base64 32 or encryptcookie.GenerateKey(32). Avoid dynamically generating a new Key with encryptcookie.GenerateKey(32) at each application startup to prevent rendering previously encrypted data inaccessible.

Config

Property	Type	Description	Default
Next	func(fiber.Ctx) bool	A function to skip this middleware when returned true.	nil
Except	[]string	Array of cookie keys that should not be encrypted.	[]
Key	string	A base64-encoded unique key to encode & decode cookies. Required. Key length should be 32 characters.	(No default, required field)
Encryptor	func(decryptedString, key string) (string, error)	A custom function to encrypt cookies.	EncryptCookie
Decryptor	func(encryptedString, key string) (string, error)	A custom function to decrypt cookies.	DecryptCookie

Default Config

var ConfigDefault = Config{
    Next:      nil,
    Except:    []string{},
    Key:       "",
    Encryptor: EncryptCookie,
    Decryptor: DecryptCookie,
}

Usage With Other Middlewares That Reads Or Modify Cookies

Place the encryptcookie middleware before any other middleware that reads or modifies cookies. For example, if you are using the CSRF middleware, ensure that the encryptcookie middleware is placed before it. Failure to do so may prevent the CSRF middleware from reading the encrypted cookie.

You may also choose to exclude certain cookies from encryption. For instance, if you are using the CSRF middleware with a frontend framework like Angular, and the framework reads the token from a cookie, you should exclude that cookie from encryption. This can be achieved by adding the cookie name to the Except array in the configuration:

app.Use(encryptcookie.New(encryptcookie.Config{
    Key:    "secret-thirty-2-character-string",
    Except: []string{csrf.ConfigDefault.CookieName}, // exclude CSRF cookie
}))
app.Use(csrf.New(csrf.Config{
    KeyLookup:      "header:" + csrf.HeaderName,
    CookieSameSite: "Lax",
    CookieSecure:   true,
    CookieHTTPOnly: false,
}))

Encryption Algorithms

The default Encryptor and Decryptor functions use AES-256-GCM for encryption and decryption. If you need to use AES-128 or AES-192 instead, you can do so by changing the length of the key when calling encryptcookie.GenerateKey(length) or by providing a key of one of the following lengths:

• AES-128 requires a 16-byte key.
• AES-192 requires a 24-byte key.
• AES-256 requires a 32-byte key.

For example, to generate a key for AES-128:

key := encryptcookie.GenerateKey(16)

And for AES-192:

key := encryptcookie.GenerateKey(24)