Advanced cookie library for Go, support signed cookies.

1. Lazy: Since cookie verification against multiple keys could be expensive, cookies are only verified lazily when accessed, not eagerly on each request.
2. Convenient: Signed cookies are stored the same way as unsigned cookies. An additional signature cookie is stored for each signed cookie, using a standard naming convention (cookie-name.sig). This allows other libraries to access the original cookies without having to know the signing mechanism.
3. compatibility for https://github.com/pillarjs/cookies

It returns a Cookies instance with optional keygrip for signed cookies.

It set the given cookie to the response and returns the current context to allow chaining. If options omit, it will use default options.

Options:

• MaxAge: a number representing the milliseconds for expiry (default to 0)
• Path: a string indicating the path of the cookie (default to "/").
• Domain: a string indicating the domain of the cookie (default to "").
• Secure: a boolean indicating whether the cookie is only to be sent over HTTP(S) (default to false).
• HTTPOnly: a boolean indicating whether the cookie is only to be sent over HTTP(S) (default to true).
• Signed: a boolean indicating whether the cookie is to be signed (default to false). If this is true, another cookie of the same name with the .sig suffix appended will also be sent.

It returns the cookie with the given name from the Cookie header in the request. If such a cookie exists, its value is returned. Otherwise, nothing is returned. signed = true can optionally be passed as the second parameter. In this case, a signature cookie (a cookie of same name ending with the .sig suffix appended) is fetched. If the signature cookie does exist, cookie will check the hash of cookie-value whether matches registered keys.

package main

import (
  "net/http"

  "github.com/go-http-utils/cookie"
)

func main() {
  http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    cookies := cookie.New(w, r, "some key")

    cookies.Set("test", "some cookie", &cookie.Options{
      Signed:   true,
      HTTPOnly: true,
    })

    value, err := cookies.Get("test", true)
    if err != nil {
      w.WriteHeader(500)
      w.Write([]byte(err.Error()))
    } else {
      w.Write([]byte(value))
    }
  })

  http.ListenAndServe(":8080", nil)
}