OAuth / OpenID Connect Sub Claim Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching oauth / openid connect sub claim, ported and verified for Python. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. 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

# OAuth / OpenID Connect Sub Claim
# ReDoS-safe | RegexVault — Identity & PII > Digital Identity

import re

oauth_openid_connect_sub_claim_pattern = re.compile(r'^[A-Za-z0-9\-._|]{8,255}$')

def validate_oauth_openid_connect_sub_claim(value: str) -> bool:
    return bool(oauth_openid_connect_sub_claim_pattern.fullmatch(value))

# Example
print(validate_oauth_openid_connect_sub_claim("248289761001"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Digital Identity 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

OIDC sub (subject) is a locally unique, never-reassigned identifier for the end user. Format is provider-specific: Google uses numeric strings, Auth0 uses provider|id format, Okta uses UUID format. Must be stable and not reassigned.