Why is this an issue?
Most of cryptographic systems require a sufficient key size to be robust against brute-force attacks.
NIST recommendations will be checked for these
use-cases:
Digital Signature Generation and Verification:
- p ≥ 2048 AND q ≥ 224 for DSA (
p is key length and q the modulus length)
- n ≥ 2048 for RSA (
n is the key length)
Key Agreement:
- p ≥ 2048 AND q ≥ 224 for DH and MQV
- n ≥ 224 for ECDH and ECMQV (Examples:
secp192r1 is a non-compliant curve (n < 224) but secp224k1 is
compliant (n >= 224))
Symmetric keys:
This rule will not raise issues for ciphers that are considered weak (no matter the key size) like DES, Blowfish.
Noncompliant code example
val keyPairGen1 = KeyPairGenerator.getInstance("RSA")
keyPairGen1.initialize(1024) // Noncompliant
val keyPairGen5 = KeyPairGenerator.getInstance("EC")
val ecSpec1 = ECGenParameterSpec("secp112r1") // Noncompliant
keyPairGen5.initialize(ecSpec1)
val keyGen1 = KeyGenerator.getInstance("AES")
keyGen1.init(64) // Noncompliant
Compliant solution
val keyPairGen6 = KeyPairGenerator.getInstance("RSA")
keyPairGen6.initialize(2048) // Compliant
val keyPairGen5 = KeyPairGenerator.getInstance("EC")
val ecSpec1 = ECGenParameterSpec("secp256r1") // Compliant
keyPairGen5.initialize(ecSpec1)
val keyGen2 = KeyGenerator.getInstance("AES")
keyGen2.init(128) // Compliant
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