A Guide to RFCs for HTTP Authentication

HTTP (Hypertext Transfer Protocol) is a popular protocol used to transfer data over the web. One of the essential components of HTTP is authentication, which allows clients to access restricted resources by providing credentials.

Over the years, several RFCs (Request for Comments) have been published to define various authentication schemes for use with HTTP.

In this article, we will explore some of the most commonly used RFCs that deal with HTTP authentication.

1. RFC 7235: This RFC provides a framework for authentication and authorization in HTTP, allowing servers to challenge clients for credentials and support a range of authentication schemes. One advantage is its flexibility, as it allows for different authentication schemes to be used. A potential disadvantage is that it requires careful implementation to ensure that sensitive user information is not leaked.
2. RFC 7616: This RFC specifies the use of HTTP Digest Authentication, which provides a secure way to authenticate clients using a hash function. One advantage is that it provides a higher level of security than Basic Authentication. A potential disadvantage is that it requires more computational resources to compute the hash function, which can slow down the authentication process.
3. RFC 7617: This RFC specifies the use of Basic Authentication with username and password credentials encoded in base64. One advantage is its simplicity, as it does not require any additional software or cryptographic algorithms. A potential disadvantage is that it does not provide strong security, as the credentials can easily be decoded if intercepted.
4. RFC 2069: This RFC defines an early version of HTTP Digest Authentication, which has since been updated and improved upon in later RFCs. One advantage is that it provided a framework for HTTP authentication when it was first introduced. A potential disadvantage is that it is no longer considered secure and should not be used in modern applications.
5. RFC 2617: This RFC updates and obsoletes RFC 2069, providing a more secure version of HTTP Digest Authentication. One advantage is its improved security, as it uses a stronger hash function and supports integrity protection. A potential disadvantage is that it requires more computational resources than Basic Authentication.
6. RFC 2831: This RFC introduces the use of HTTP Digest Authentication with mutual authentication, allowing the client to authenticate the server as well. One advantage is its increased security, as it provides protection against man-in-the-middle attacks. A potential disadvantage is that it requires additional computational resources for the client to authenticate the server.
7. RFC 4559: This RFC defines a method for using Kerberos as an authentication scheme in HTTP. One advantage is its high level of security, as Kerberos uses strong cryptographic algorithms. A potential disadvantage is that it requires additional setup and configuration to use in HTTP.
8. RFC 7618: This RFC updates and obsoletes RFC 2617, providing additional security recommendations and clarifications for HTTP Digest Authentication. One advantage is its improved security, as it provides guidance on best practices for implementation. A potential disadvantage is that it may not be widely adopted, as it is a relatively new RFC.

Q. Why Basic authentication credentials are encoded using base64 when it can easily be decoded ?

Encoding Basic authentication credentials using base64 is not aimed at providing encryption or security, but rather to ensure that they can be transmitted compatibly with the HTTP protocol.

Since HTTP is a text-based protocol, it only accepts ASCII characters for transmission. However, user credentials may contain non-ASCII characters, which can cause problems during transmission and lead to authentication failures.

Base64 encoding helps to overcome this challenge by transforming the credentials into ASCII characters that can be transmitted without any potential issues of character encoding. Furthermore, it offers a straightforward and lightweight method of converting binary data such as the username and password into a suitable format for internet transmission.

Links to the RFCs mentioned in this article:

RFC 7235: https://tools.ietf.org/html/rfc7235
RFC 7616: https://tools.ietf.org/html/rfc7616
RFC 7617: https://tools.ietf.org/html/rfc7617
RFC 2069: https://tools.ietf.org/html/rfc2069
RFC 2617: https://tools.ietf.org/html/rfc2617
RFC 2831: https://tools.ietf.org/html/rfc2831
RFC 4559: https://tools.ietf.org/html/rfc4559
RFC 7618: https://tools.ietf.org/html/rfc7618