🐛 [Bug]: X-Forwarded-Host, X-Forwarded-Proto, X-Forwarded-Protocol can have a comma-separated list

[supakornbabe]

Bug Description

The implement of c.Protocol() and c.Hostname() is wrong and the problem is happen when request is go through more than 1 proxies.

Reference: https://httpd.apache.org/docs/2.2/mod/mod_proxy.html#page-header

Be careful when using these headers on the origin server, since they will contain more than one (comma-separated) value if the original request already contained one of these headers. For example, you can use %{X-Forwarded-For}i in the log format string of the origin server to log the original clients IP address, but you may get more than one address if the request passes through several proxies.

xp-framework/xp-framework#162

How to Reproduce

Steps to reproduce the behavior:

1. Set up go fiber behind 2 proxies
2. Use c.BaseURL(), c.Protocol(), c.Hostname() then these return comma separated list

BaseURL: https, https://hello.world.com, hello.world.com
Protocol: https, https
Hostname: hello.world.com, hello.world.com

Expected Behavior

c.BaseURL(), c.Protocol(), c.Hostname() return only first item in list

Reference: xp-framework/xp-framework#162

Fiber Version

v2.38.1

Code Snippet (optional)

package main

import "github.com/gofiber/fiber/v2"
import "log"

func main() {
  app := fiber.New()

  // Steps to reproduce

  log.Fatal(app.Listen(":3000"))
}

func LoginHandler(c *fiber.Ctx) error {
	fmt.Println("BaseURL: "+c.BaseURL())
	fmt.Println("Protocol: "+c.Protocol())
        fmt.Println("Hostname: "+c.Hostname())
}

Result
BaseURL: https, https://hello.world.com, hello.world.com
Protocol: https, https
Hostname: hello.world.com, hello.world.com

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my problem prior to opening this one.
• I understand that improperly formatted bug reports may be closed without explanation.

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