cryptographic-failures

name	Cryptographic Failures
description	This skill should be used when the user asks about "cryptographic failures", "weak encryption", "hardcoded secrets", "insecure random", "MD5", "SHA1", "weak hashing", or needs to find crypto-related vulnerabilities during whitebox security review.
version	1.0.0

Cryptographic Failures (OWASP A02)

Purpose

Provide detection patterns for cryptographic vulnerabilities including weak algorithms, hardcoded secrets, insufficient key lengths, and insecure random number generation.

OWASP Top 10 Mapping

Category: A02 - Cryptographic Failures

CWEs:

• CWE-326: Inadequate Encryption Strength
• CWE-327: Use of Broken or Risky Crypto Algorithm
• CWE-328: Reversible One-Way Hash
• CWE-330: Use of Insufficiently Random Values
• CWE-338: Use of Cryptographically Weak PRNG
• CWE-798: Use of Hardcoded Credentials

When to Use

Activate this skill when:

• Reviewing password hashing implementations
• Checking encryption algorithm usage
• Looking for hardcoded secrets/API keys
• Auditing random number generation
• Verifying key management practices

---

Weak Hash Algorithms

Detection Patterns

# MD5 usage (broken for security)
grep -rniE "md5\(|MD5\.|hashlib\.md5|MessageDigest.*MD5|crypto\.MD5" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# SHA1 usage (deprecated for security)
grep -rniE "sha1\(|SHA1\.|hashlib\.sha1|MessageDigest.*SHA-1|crypto\.SHA1" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Password hashing with weak algorithms
grep -rniE "password.*md5|password.*sha1|hash.*password.*md5" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

Language-Specific Patterns

Python

# Weak hashing
grep -rniE "hashlib\.md5|hashlib\.sha1" --include="*.py"

# Should use: bcrypt, argon2, scrypt
grep -rniE "bcrypt|argon2|scrypt" --include="*.py"

Vulnerable:

# VULNERABLE: MD5 for passwords
password_hash = hashlib.md5(password.encode()).hexdigest()

Secure:

# SAFE: bcrypt for passwords
password_hash = bcrypt.hashpw(password.encode(), bcrypt.gensalt())

Java

# Weak MessageDigest
grep -rniE "MessageDigest\.getInstance.*MD5|MessageDigest\.getInstance.*SHA-1" --include="*.java"

# Should use: BCrypt, Argon2, PBKDF2
grep -rniE "BCrypt|Argon2|PBKDF2|SecretKeyFactory" --include="*.java"

Go

# Weak crypto imports
grep -rniE "crypto/md5|crypto/sha1" --include="*.go"

# Should use: bcrypt, argon2
grep -rniE "golang\.org/x/crypto/bcrypt|golang\.org/x/crypto/argon2" --include="*.go"

PHP

# Weak hashing
grep -rniE "md5\(|sha1\(" --include="*.php"

# Should use: password_hash
grep -rniE "password_hash|PASSWORD_BCRYPT|PASSWORD_ARGON2" --include="*.php"

TypeScript

# Weak crypto
grep -rniE "createHash.*md5|createHash.*sha1" --include="*.ts"

# Should use: bcrypt
grep -rniE "bcrypt\.hash|argon2" --include="*.ts"

---

Weak Encryption Algorithms

Detection Patterns

# DES (broken)
grep -rniE "DES|DESede|TripleDES" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# RC4 (broken)
grep -rniE "RC4|ARC4|ARCFOUR" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# ECB mode (insecure)
grep -rniE "ECB|AES/ECB|MODE_ECB" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Blowfish (deprecated)
grep -rniE "Blowfish|BLOWFISH" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

Secure Alternatives

Weak	Secure Alternative
DES	AES-256
3DES	AES-256
RC4	ChaCha20 or AES-GCM
ECB mode	GCM or CBC with HMAC
Blowfish	AES-256
RSA-1024	RSA-2048+ or ECDSA

---

Hardcoded Secrets

Detection Patterns

# API keys
grep -rniE "api[_-]?key\s*[=:]\s*['\"][a-zA-Z0-9]{16,}['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Passwords
grep -rniE "password\s*[=:]\s*['\"][^'\"]+['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Secret keys
grep -rniE "secret[_-]?key\s*[=:]\s*['\"][^'\"]+['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# AWS credentials
grep -rniE "AKIA[0-9A-Z]{16}|aws_secret_access_key" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php" --include="*.env"

# Private keys
grep -rniE "BEGIN RSA PRIVATE KEY|BEGIN PRIVATE KEY|BEGIN EC PRIVATE KEY" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php" --include="*.pem"

# JWT secrets
grep -rniE "jwt[_-]?secret\s*[=:]\s*['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

High-Entropy String Detection

# Long alphanumeric strings (potential secrets)
grep -rniE "['\"][a-zA-Z0-9+/=]{32,}['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

---

Insecure Random Number Generation

Detection Patterns

# JavaScript/TypeScript - Math.random (NOT cryptographically secure)
grep -rniE "Math\.random\(\)" --include="*.ts" --include="*.js"

# Python - random module (NOT cryptographically secure)
grep -rniE "import random|from random|random\.random|random\.randint" --include="*.py"

# Java - java.util.Random (NOT cryptographically secure)
grep -rniE "new Random\(\)|java\.util\.Random" --include="*.java"

# PHP - rand/mt_rand (NOT cryptographically secure)
grep -rniE "rand\(|mt_rand\(" --include="*.php"

# Go - math/rand (NOT cryptographically secure)
grep -rniE "math/rand|rand\.Intn|rand\.Int\(" --include="*.go"

Secure Alternatives

Language	Insecure	Secure
Python	random.random()	secrets.token_bytes()
Java	java.util.Random	java.security.SecureRandom
Go	math/rand	crypto/rand
JavaScript	Math.random()	crypto.randomBytes()
PHP	rand(), mt_rand()	random_bytes(), random_int()

---

Insufficient Key Length

Detection Patterns

# RSA key size (should be 2048+)
grep -rniE "RSA.*1024|keysize.*1024|KeyPairGenerator.*1024" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# AES key size (should be 256 for sensitive data)
grep -rniE "AES.*128|aes-128" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# HMAC key size
grep -rniE "hmac.*key.*['\"][a-zA-Z0-9]{1,15}['\"]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

Minimum Key Lengths

Algorithm	Minimum	Recommended
RSA	2048 bits	4096 bits
AES	128 bits	256 bits
ECDSA	256 bits	384 bits
HMAC	256 bits	512 bits

---

Predictable IVs/Nonces

Detection Patterns

# Static/zero IV
grep -rniE "iv\s*=\s*['\"]0{16,}['\"]|iv\s*=\s*bytes\(16\)|iv.*\[0,0,0" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Reused nonce
grep -rniE "nonce\s*=\s*['\"]|static.*nonce|const.*nonce" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

---

Missing Encryption

Detection Patterns

# Plaintext password storage
grep -rniE "password\s*=\s*request|user\.password\s*=\s*" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# HTTP instead of HTTPS
grep -rniE "http://[^localhost]|http://[^127\.0\.0\.1]" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php"

# Unencrypted database connection
grep -rniE "sslmode=disable|useSSL=false|ssl=false" --include="*.go" --include="*.py" --include="*.java" --include="*.ts" --include="*.php" --include="*.env"

---

Broken Certificate Validation

Detection Patterns

# Go - Skip TLS verification
grep -rniE "InsecureSkipVerify\s*:\s*true" --include="*.go"

# Python - Disable SSL verification
grep -rniE "verify\s*=\s*False|CERT_NONE" --include="*.py"

# Java - Trust all certificates
grep -rniE "TrustAllCerts|X509TrustManager|checkServerTrusted.*return" --include="*.java"

# Node.js - Reject unauthorized false
grep -rniE "rejectUnauthorized\s*:\s*false|NODE_TLS_REJECT_UNAUTHORIZED" --include="*.ts" --include="*.js"

# PHP - Disable SSL verification
grep -rniE "CURLOPT_SSL_VERIFYPEER\s*=>\s*false|verify_peer.*false" --include="*.php"

---

Secure Patterns

Password Hashing

# Python - Argon2 (recommended)
from argon2 import PasswordHasher
ph = PasswordHasher()
hash = ph.hash(password)

// Java - BCrypt
String hash = BCrypt.hashpw(password, BCrypt.gensalt(12));

// Go - bcrypt
hash, _ := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)

Encryption

# Python - AES-GCM
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
key = AESGCM.generate_key(bit_length=256)
aesgcm = AESGCM(key)
nonce = os.urandom(12)  # Random nonce
ciphertext = aesgcm.encrypt(nonce, plaintext, None)

Random Generation

# Python - Secure random
import secrets
token = secrets.token_hex(32)

---

Verification Checklist

• No MD5/SHA1 for password hashing
• No DES/RC4/ECB encryption
• No hardcoded secrets
• Cryptographically secure RNG used
• Key lengths meet minimums
• Random IVs/nonces
• TLS 1.2+ with valid certificates
• Secrets from environment/vault

---

CWE References

CWE	Name	Example
CWE-326	Inadequate Encryption	RSA-1024
CWE-327	Broken Crypto	MD5, DES, RC4
CWE-328	Reversible Hash	MD5 for passwords
CWE-330	Insufficient Randomness	Math.random for tokens
CWE-338	Weak PRNG	rand() for crypto
CWE-798	Hardcoded Credentials	API keys in code