OAuth / OpenID Connect Sub Claim Regex for PHP

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching oauth / openid connect sub claim, ported and verified for PHP. 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 PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

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

define('OAUTH_OPENID_CONNECT_SUB_CLAIM_PATTERN', '/^[A-Za-z0-9\-._|]{8,255}$/');

function validate_oauth_openid_connect_sub_claim(string $input): bool {
    return (bool) preg_match(OAUTH_OPENID_CONNECT_SUB_CLAIM_PATTERN, $input);
}

// Example
var_dump(validate_oauth_openid_connect_sub_claim("248289761001")); // bool(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 PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. 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.