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@26zl/performing-cryptographic-audit-of-application

A

A cryptographic audit systematically reviews an application's use of

skillclaude

Install

agr install @26zl/performing-cryptographic-audit-of-application --target claude

Writes 2 files into .claude/skills/, pinned to git-b1b2cc28.

  • .claude/skills/performing-cryptographic-audit-of-application/LICENSE
  • .claude/skills/performing-cryptographic-audit-of-application/SKILL.md

Document


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 mitre_attack:
  • T1600
  • T1573
  • T1553

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

Prerequisites

  • Familiarity with cryptography concepts and tools
  • Access to a test or lab environment for safe execution
  • Python 3.8+ with required dependencies installed
  • Appropriate authorization for any testing activities

Objectives

  • Detect usage of deprecated algorithms (MD5, SHA-1, DES, RC4)
  • Identify insecure cipher modes (ECB) and padding schemes
  • Find hardcoded keys, passwords, and secrets in source code
  • Verify TLS/SSL configuration strength
  • Check key derivation function parameters
  • Validate random number generator usage
  • Produce a structured audit report with findings and remediation

Key Concepts

Cryptographic Weakness Categories

CategoryExamplesRisk Level
Weak HashingMD5, SHA-1 for integrity/signaturesHigh
Insecure EncryptionDES, 3DES, RC4, BlowfishHigh
Bad Cipher ModeECB mode for any block cipherHigh
Insufficient Key SizeRSA < 2048, AES-128 for long-termMedium
Hardcoded SecretsKeys/passwords in source codeCritical
Weak KDFLow iteration PBKDF2, plain MD5High
Poor Entropytime-based seeds, predictable IVsHigh
Deprecated ProtocolsSSLv3, TLS 1.0, TLS 1.1High

Security Considerations

  • Review both application code and configuration files
  • Check third-party dependencies for known crypto vulnerabilities
  • Verify certificates and TLS configurations on deployed servers
  • Ensure secrets are loaded from environment variables or vaults
  • Review key storage and rotation practices

Validation Criteria

  • Scanner detects all injected test weaknesses
  • MD5/SHA-1 usage for security purposes is flagged
  • ECB mode usage is flagged
  • Hardcoded keys/passwords are detected
  • Weak KDF parameters are identified
  • Report includes severity, location, and remediation
  • False positive rate is below 10%

Trustgrade A

  • passBody integrity

    Whether the stored document is plausibly the kind of file the artifact declares, rather than something fetched by mistake.

  • passType matchnot applicable to this artifact type

    Whether the artifact is really the kind of thing its metadata claims it is.

  • passFreshness

    How long since the source repository was last pushed to.

  • passPrompt injection

    Scans the artifact's own text for instructions aimed at your agent rather than at you.

  • passLicense

    Whether the source repository declares an SPDX license permissive enough to redistribute.

How the grade is calculated

Each check contributes 0 points when it passes, 1 when it warns, and 2 when it fails. The total maps to a letter:

  • Aevery check passed
  • Bone warning
  • Ctwo warnings
  • Dprompt injection or body integrity failed, or three warnings
  • Fone of those failed, and something else is wrong

These are automated hygiene checks, not a security audit, and not a dependency or vulnerability scan. A grade of A means nothing was flagged — not that the artifact is safe.

Versions

  • git-b1b2cc2843252026-07-31