Browser Fingerprint Hash Regex for Go

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching browser fingerprint hash, 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

// Browser Fingerprint Hash
// ReDoS-safe | RegexVault — Identity & PII > Digital Identity

package validation

import "regexp"

var browserFingerprintHashRe = regexp.MustCompile(`^[0-9a-f]{32}$|^[0-9a-f]{64}$`)

func ValidateBrowserFingerprintHash(s string) bool {
    return browserFingerprintHashRe.MatchString(s)
}

// Example
// fmt.Println(ValidateBrowserFingerprintHash("d41d8cd98f00b204e9800998ecf8427e")) // 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

Browser fingerprinting combines canvas, WebGL, fonts, plugins, and device characteristics into a hash. Under GDPR recital 30, fingerprinting constitutes tracking. Under ePrivacy Directive, it requires consent. 32 chars = MD5, 64 chars = SHA-256.