OAuth / OpenID Connect Sub Claim Regex for Go

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching oauth / openid connect sub claim, ported and verified for Go. 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 Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

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

package validation

import "regexp"

var oauthOpenidConnectSubClaimRe = regexp.MustCompile(`^[A-Za-z0-9\-._|]{8,255}$`)

func ValidateOauthOpenidConnectSubClaim(s string) bool {
    return oauthOpenidConnectSubClaimRe.MatchString(s)
}

// Example
// fmt.Println(ValidateOauthOpenidConnectSubClaim("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 Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. 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.