| name | performing-cryptographic-audit-of-application |
| description | A cryptographic audit systematically reviews an application's use of cryptographic primitives, protocols, and key management to identify vulnerabilities such as weak algorithms, insecure modes, hardco |
| domain | cybersecurity |
| subdomain | cryptography |
| tags | ["cryptography","audit","security-review","compliance","vulnerability-assessment"] |
| version | 1.0 |
| author | mahipal |
| license | Apache-2.0 |
| nist_csf | ["PR.DS-01","PR.DS-02","PR.DS-10"] |
Performing Cryptographic Audit of Application
Overview
A cryptographic audit systematically reviews an application's use of cryptographic primitives, protocols, and key management to identify vulnerabilities such as weak algorithms, insecure modes, hardcoded keys, insufficient entropy, and protocol misconfigurations. This skill covers building an automated crypto audit tool that scans Python and configuration files for common cryptographic weaknesses.
When to Use
- When conducting security assessments that involve performing cryptographic audit of application
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing
Most Often Missed & How to Confirm
Automated crypto audits routinely under-report because scanners only grep for obvious names. The items below are the ones most often skipped — check every one before concluding a codebase is clean.
- Hardcoded keys/secrets beyond
password=: base64/hex byte-string literals passed straight into AESGCM(key) or Fernet(key), IVs/nonces defined as constants, and .pem/.env files committed to the repo. Grep for Cipher(, os.urandom results assigned at module scope, and high-entropy string literals — not just the word "secret".
- Weak PRNG for crypto:
random.random(), random.randint, numpy.random, or time-seeded values used for keys/IVs/tokens/salts. Flag any non-secrets/os.urandom source feeding a crypto API.
- Deprecated TLS / cipher config:
ssl.PROTOCOL_TLSv1, ssl_version=TLSv1_1, CERT_NONE/check_hostname=False, and server configs allowing SSLv3/TLS1.0/1.1 or RC4/3DES/EXPORT suites. Audit config files and live endpoints, not just code.
- Insecure modes / weak KDF hiding in wrappers:
modes.ECB(), static IVs, PBKDF2 with low iterations, MD5/SHA-1 used as a "KDF", and hashlib.md5(password) for storage.
- Positive signal (how to confirm a real finding vs. noise): a true positive is reachable application code where attacker-influenced data meets the weak primitive — confirm the call is live (not test/vendored/dead code), trace the key/IV to its actual source, and show the concrete impact (e.g., ECB on PII, MD5 for password storage). Report severity, file:line, and remediation; keep false positives <10% by excluding , fixtures, and non-security hash uses (e.g., MD5 for a cache key).
