AWS Secret Access Key Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching aws secret access key, ported and verified for Python. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# AWS Secret Access Key
# ReDoS-safe | RegexVault — Security > API Keys & Tokens

import re

aws_secret_access_key_pattern = re.compile(r'(?:aws_secret_access_key|AWS_SECRET_ACCESS_KEY|secret.?access.?key)(?:[\s=:"']+)([A-Za-z0-9/+=]{40})(?:["'\s]|$)')

def validate_aws_secret_access_key(value: str) -> bool:
    return bool(aws_secret_access_key_pattern.fullmatch(value))

# Example
print(validate_aws_secret_access_key("aws_secret_access_key = wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Security > API Keys & Tokens category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Context-aware pattern — requires the key name label to be present (common in config files, environment variables, and .env files). The secret itself is 40 base64 characters. Bare 40-char base64 strings without the label context are too broad to match reliably.