HashiCorp Vault Token Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching hashicorp vault token, 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

// HashiCorp Vault Token
// ReDoS-safe | RegexVault — Security > Secrets & Config

package validation

import "regexp"

var hashicorpVaultTokenRe = regexp.MustCompile(`^(?:hvs\.|s\.)[A-Za-z0-9]{20,200}$`)

func ValidateHashicorpVaultToken(s string) bool {
    return hashicorpVaultTokenRe.MatchString(s)
}

// Example
// fmt.Println(ValidateHashicorpVaultToken("hvs.CAESILdJHHVdRKmXpGGNVRpzuIMz8NuNEMFWMJ0ZjUVNxWqp")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Security > Secrets & Config 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

Vault tokens: older format uses s. prefix; newer (Vault 1.10+) uses hvs. for service tokens, hvb. for batch tokens, hvr. for recovery tokens. Tokens expire based on TTL and are linked to specific Vault policies. Revoke via vault token revoke if exposed.