InsufficientPasswordHash.qhelp

<!DOCTYPE qhelp PUBLIC
"-//Semmle//qhelp//EN"
"qhelp.dtd">
<qhelp>

<overview>
	<p>
		Storing cryptographic hashes of passwords is standard security
		practice, but it is equally important to select the right
		hashing scheme.

		If an attacker obtains the hashed passwords of an application,
		the password hashing scheme should still prevent the attacker
		from easily obtaining the original cleartext passwords.
	</p>

	<p>
		A good password hashing scheme requires a computation that
		cannot be done efficiently. Standard hashing schemes, such as
		<code>md5</code> or <code>sha1</code>, are efficiently
		computable, and are therefore not suitable for password
		hashing.
	</p>
</overview>

<recommendation>
	<p>
		Use a secure password hashing scheme such as
		<code>bcrypt</code>, <code>scrypt</code>, <code>PBKDF2</code>,
		or <code>Argon2</code>.
	</p>
</recommendation>

<example>
	<p>
		In the example below, the <code>md5</code> algorithm computes
		the hash of a password.
	</p>

	<sample src="examples/InsufficientPasswordHash.js"/>

	<p>
		This is not secure, since the password can be efficiently
		cracked by an attacker that obtains the hash. A more secure
		scheme is to hash the password with the <code>bcrypt</code>
		algorithm:
	</p>

	<sample src="examples/InsufficientPasswordHash_fixed.js"/>
</example>

<references>
	<li>OWASP: <a href="https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html">Password storage</a>.</li>
</references>
</qhelp>