sign.go

package getstream

import (
	"crypto/hmac"
	"crypto/sha1"
	"encoding/base64"
	"strings"
)

func urlSafe(src string) string {
	src = strings.Replace(src, "+", "-", -1)
	src = strings.Replace(src, "/", "_", -1)
	src = strings.Trim(src, "=")
	return src
}

func Sign(secret, message string) string {
	hash := sha1.New()
	hash.Write([]byte(secret))
	key := hash.Sum(nil)
	mac := hmac.New(sha1.New, key)
	mac.Write([]byte(message))
	digest := base64.StdEncoding.EncodeToString(mac.Sum(nil))
	return urlSafe(digest)
}

func SignSlug(secret string, slug Slug) Slug {
	return Slug{slug.Slug, slug.ID, Sign(secret, slug.Slug+slug.ID)}
}

func SignActivity(secret string, activity *Activity) *Activity {
	result := &Activity{}
	*result = *activity
	for i, slug := range result.To {
		result.To[i] = SignSlug(secret, slug)
	}

	return result
}