OpenID Connect ID Token (JWT) Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching openid connect id token (jwt), ported and verified for Go. 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 Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// OpenID Connect ID Token (JWT)
// ReDoS-safe | RegexVault — Security > OAuth & OIDC

package validation

import "regexp"

var openidConnectIdTokenJwtRe = regexp.MustCompile(`^([A-Za-z0-9_-]+)\.([A-Za-z0-9_-]+)\.([A-Za-z0-9_-]*)$`)

func ValidateOpenidConnectIdTokenJwt(s string) bool {
    return openidConnectIdTokenJwtRe.MatchString(s)
}

// Example
// fmt.Println(ValidateOpenidConnectIdTokenJwt("eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJ1c2VyMTIzIiwiYXVkIjoiY2xpZW50XzEifQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Security > OAuth & OIDC 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 ID tokens are JWTs with specific required claims: iss (issuer), sub (subject), aud (audience), exp (expiry), iat (issued at). Always validate: 1) signature, 2) iss matches expected provider, 3) aud matches client_id, 4) exp is in the future, 5) nonce (if used). Never trust an ID token without validation.