BrokenCryptoAlgorithm.qhelp

<!DOCTYPE qhelp PUBLIC
"-//Semmle//qhelp//EN"
"qhelp.dtd">
<qhelp>
	<overview>
		<p>
			Using broken or weak cryptographic algorithms may compromise
			security guarantees such as confidentiality, integrity, and
			authenticity.
		</p>

		<p>
			Many cryptographic algorithms are known to be weak or flawed. The
			security guarantees of a system often rely on the underlying
			cryptography, so using a weak algorithm can have severe consequences.
			For example:
		</p>

		<ul>
			<li>
			If a weak encryption algorithm is used, an attacker may be able to
			decrypt sensitive data.
			</li>
			<li>
			If a weak hashing algorithm is used to protect data integrity, an
			attacker may be able to craft a malicious input that has the same
			hash as a benign one.
			</li>
			<li>
			If a weak algorithm is used for digital signatures, an attacker may
			be able to forge signatures and impersonate legitimate users.
			</li>
		</ul>

	</overview>
	<recommendation>

		<p>
			Ensure that you use a strong, modern cryptographic
			algorithm. Use at least AES-128 or RSA-2048 for
			encryption, and SHA-2 or SHA-3 for secure hashing.
		</p>

	</recommendation>
	<example>

		<p>
			The following code shows an example of using the builtin
			cryptographic library of NodeJS to encrypt some secret
			data. When creating a <code>Cipher</code> instance to encrypt
			the secret data with, you must specify the encryption
			algorithm to use. The first example uses DES, which is an
			older algorithm that is now considered weak. The second
			example uses AES, which is a strong modern algorithm.
		</p>

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

	</example>

	<references>
		<li>NIST, FIPS 140 Annex a: <a href="http://csrc.nist.gov/publications/fips/fips140-2/fips1402annexa.pdf"> Approved Security Functions</a>.</li>
		<li>NIST, SP 800-131A: <a href="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar1.pdf"> Transitions: Recommendation for Transitioning the Use of Cryptographic Algorithms and Key Lengths</a>.</li>
		<li>OWASP: <a
		href="https://cheatsheetseries.owasp.org/cheatsheets/Cryptographic_Storage_Cheat_Sheet.html#rule---use-strong-approved-authenticated-encryption">Rule
		- Use strong approved cryptographic algorithms</a>.
		</li>
	</references>

</qhelp>