== Why is this an issue?

When generating cryptographic keys (or key pairs), it is important to use strong parameters. Key length, for instance, should provide enough entropy against brute-force attacks. 


* For ``++RSA++`` and ``++DSA++`` algorithms key size should be at least 2048 bits long
* For ``++ECC++`` (elliptic curve cryptography) algorithms key size should be at least 224 bits long
* For ``++RSA++`` public key exponent should be at least 65537.

This rule raises an issue when a ``++RSA++``, ``++DSA++`` or ``++ECC++`` key-pair generator is initialized using weak parameters. 

It supports the following libraries:

* https://github.com/pyca/cryptography[cryptography]
* https://github.com/dlitz/pycrypto[PyCrypto]
* https://github.com/Legrandin/pycryptodome[Cryptodome]

=== Noncompliant code example

[source,python]
----
from cryptography.hazmat.primitives.asymmetric import rsa, ec, dsa

dsa.generate_private_key(key_size=1024, backend=backend) # Noncompliant
rsa.generate_private_key(public_exponent=999, key_size=2048, backend=backend) # Noncompliant
ec.generate_private_key(curve=ec.SECT163R2, backend=backend)  # Noncompliant
----

=== Compliant solution

[source,python]
----
from cryptography.hazmat.primitives.asymmetric import rsa, ec, dsa

dsa.generate_private_key(key_size=2048, backend=backend) # Compliant
rsa.generate_private_key(public_exponent=65537, key_size=2048, backend=backend) # Compliant
ec.generate_private_key(curve=ec.SECT409R1, backend=backend) # Compliant
----

== Resources

* https://owasp.org/Top10/A02_2021-Cryptographic_Failures/[OWASP Top 10 2021 Category A2] - Cryptographic Failures
* https://www.owasp.org/www-project-top-ten/2017/A3_2017-Sensitive_Data_Exposure[OWASP Top 10 2017 Category A3] - Sensitive Data Exposure
* https://owasp.org/www-project-top-ten/2017/A6_2017-Security_Misconfiguration[OWASP Top 10 2017 Category A6] - Security Misconfiguration
* https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf[NIST FIPS 186-4] - Digital Signature Standard (DSS)
* https://cwe.mitre.org/data/definitions/326[MITRE, CWE-326] - Inadequate Encryption Strength

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