Refactor authentication handler

Signed-off-by: gearnode <bryan@frimin.fr>

pkg/securecookie/securecookie.go

@@ -0,0 +1,164 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package securecookie
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+var (
+	ErrInvalidCookie    = errors.New("invalid cookie")
+	ErrCookieNotFound   = errors.New("cookie not found")
+	ErrInvalidSignature = errors.New("invalid signature")
+)
+
+// Config holds the configuration for secure cookies
+type Config struct {
+	// Name is the name of the cookie
+	Name string
+
+	// Secret is the secret key used for signing cookies
+	Secret string
+
+	// Domain is the cookie domain
+	Domain string
+
+	// Path is the cookie path
+	Path string
+
+	// MaxAge is the maximum age of the cookie in seconds
+	MaxAge int
+
+	// Secure indicates if the cookie should only be sent over HTTPS
+	Secure bool
+
+	// HTTPOnly indicates if the cookie should be inaccessible to JavaScript
+	HTTPOnly bool
+
+	// SameSite defines the SameSite attribute of the cookie
+	SameSite http.SameSite
+}
+
+// DefaultConfig returns a default secure cookie configuration
+func DefaultConfig(name, secret string) Config {
+	return Config{
+		Name:     name,
+		Secret:   secret,
+		Path:     "/",
+		MaxAge:   86400 * 30, // 30 days
+		Secure:   true,
+		HTTPOnly: true,
+		SameSite: http.SameSiteStrictMode,
+	}
+}
+
+// Set creates and sets a secure cookie with the given value
+func Set(w http.ResponseWriter, config Config, value string) error {
+	signedValue, err := Sign(value, config.Secret)
+	if err != nil {
+		return fmt.Errorf("failed to sign cookie value: %w", err)
+	}
+
+	cookie := &http.Cookie{
+		Name:     config.Name,
+		Value:    signedValue,
+		Path:     config.Path,
+		Domain:   config.Domain,
+		MaxAge:   config.MaxAge,
+		Secure:   config.Secure,
+		HttpOnly: config.HTTPOnly,
+		SameSite: config.SameSite,
+	}
+
+	http.SetCookie(w, cookie)
+	return nil
+}
+
+// Get retrieves and verifies a secure cookie
+func Get(r *http.Request, config Config) (string, error) {
+	cookie, err := r.Cookie(config.Name)
+	if err != nil {
+		return "", ErrCookieNotFound
+	}
+
+	value, err := Verify(cookie.Value, config.Secret)
+	if err != nil {
+		return "", ErrInvalidCookie
+	}
+
+	return value, nil
+}
+
+// Clear removes a cookie by setting its expiration in the past
+func Clear(w http.ResponseWriter, config Config) {
+	cookie := &http.Cookie{
+		Name:     config.Name,
+		Value:    "",
+		Path:     config.Path,
+		Domain:   config.Domain,
+		MaxAge:   -1,
+		Expires:  time.Now().Add(-1 * time.Hour),
+		Secure:   config.Secure,
+		HttpOnly: config.HTTPOnly,
+		SameSite: config.SameSite,
+	}
+	http.SetCookie(w, cookie)
+}
+
+// Sign creates a signed value using HMAC-SHA256
+func Sign(value, secret string) (string, error) {
+	if secret == "" {
+		return "", fmt.Errorf("secret cannot be empty")
+	}
+
+	h := hmac.New(sha256.New, []byte(secret))
+	h.Write([]byte(value))
+
+	signature := base64.RawURLEncoding.EncodeToString(h.Sum(nil))
+
+	return value + "." + signature, nil
+}
+
+// Verify checks if a signed value is valid
+func Verify(signedValue, secret string) (string, error) {
+	if secret == "" {
+		return "", fmt.Errorf("secret cannot be empty")
+	}
+
+	parts := strings.Split(signedValue, ".")
+	if len(parts) != 2 {
+		return "", fmt.Errorf("invalid signed value format")
+	}
+
+	value := parts[0]
+
+	expectedSignedValue, err := Sign(value, secret)
+	if err != nil {
+		return "", fmt.Errorf("failed to sign value: %w", err)
+	}
+
+	if signedValue != expectedSignedValue {
+		return "", ErrInvalidSignature
+	}
+
+	return value, nil
+}