Most of cryptographic systems require a sufficient key size to be robust against brute-force attacks.
NIST recommendations will be checked:
| Use / Algorithm | DSA | RSA | ECDSA | DH | MQV | ECDH | ECMQV | Block Cipher | ||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Digital Signature Generation | p ≥ 2048 AND q ≥ 224 | n ≥ 2048 | See table below | x | x | x | x | x |
Digital Signature Verification | p ≥ 2048 AND q ≥ 224 | n ≥ 2048 | See table below | x | x | x | x | x |
Key Agreement | x | x | x | p ≥ 2048 AND q ≥ 224 | p ≥ 2048 AND q ≥ 224 | See table below | See table below | x |
Encryption and Decryption | x | x | x | x | x | x | x | AES-128, 192, 256 This rule will not raise issues for ciphers that are considered weak (no matter the key size) like DES, Blowfish.h3. Notation * DSA ([Digital Signature Algorithm |
https://en.wikipedia.org/wiki/Digital_Signature_Algorithm]): p is key length and q the modulus length* EC ([Elliptic-curve |
https://en.wikipedia.org/wiki/Elliptic-curve_cryptography]) |
EC parameters | EB | EC | ED | EE | ||||||
| Length of n | 224-255 | 256-383 | 384-511 | 512+ |
Maximum bit length of cofactor h | 14 | 16 | 24 |
$config = array(
"digest_alg" => "sha512",
"private_key_bits" => 1024, // Noncompliant
"private_key_type" => OPENSSL_KEYTYPE_RSA,
);
$res = openssl_pkey_new($config);
$config = array(
"digest_alg" => "sha512",
"private_key_bits" => 2048 // Compliant
"private_key_type" => OPENSSL_KEYTYPE_RSA,
);
$res = openssl_pkey_new($config);
* OWASP Top 10 2017 Category A3 - Sensitive Data Exposure
* OWASP Top 10 2017 Category A9 - Security Misconfiguration
* NIST 800-131A - Recommendation for Transitioning the Use of Cryptographic Algorithms and Key Lengths
* MITRE, CWE-326 - Inadequate Encryption Strength