REGEXVAULTv2.0
Security/Secrets & Config
Verified Safe

Private Key PEM Header Detection (Any Type) Regex for Go

/-----BEGIN (?:RSA |EC |DSA |OPENSSH |ENCRYPTED )?PRIVATE KEY-----/

What this pattern does

This page provides a well-structured, multi-part regular expression for matching private key pem header detection (any type), 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

Go
// Private Key PEM Header Detection (Any Type)
// ReDoS-safe | RegexVault — Security > Secrets & Config

package validation

import "regexp"

var privateKeyPemHeaderDetectionAnyTypeRe = regexp.MustCompile(`-----BEGIN (?:RSA |EC |DSA |OPENSSH |ENCRYPTED )?PRIVATE KEY-----`)

func ValidatePrivateKeyPemHeaderDetectionAnyType(s string) bool {
    return privateKeyPemHeaderDetectionAnyTypeRe.MatchString(s)
}

// Example
// fmt.Println(ValidatePrivateKeyPemHeaderDetectionAnyType("-----BEGIN PRIVATE KEY-----")) // true

Test Cases

Matches (Valid)
Rejects (Invalid)
-----BEGIN PRIVATE KEY----------BEGIN CERTIFICATE-----
-----BEGIN RSA PRIVATE KEY----------BEGIN PUBLIC KEY-----
-----BEGIN EC PRIVATE KEY-----BEGIN RSA PRIVATE KEY
-----BEGIN OPENSSH PRIVATE KEY-----
-----BEGIN ENCRYPTED PRIVATE KEY-----

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

ENCRYPTED PRIVATE KEY is slightly less dangerous than plain PRIVATE KEY — but the passphrase is still crackable offline. Never treat encryption as a substitute for access control.

Technical Notes

Lightweight header-only scanner. More permissive than sec-pki-02 — useful as a first-pass trigger before more expensive full-block extraction. Matches any key type including PKCS#8 (PRIVATE KEY), PKCS#1 RSA (RSA PRIVATE KEY), SEC1 EC (EC PRIVATE KEY), and OpenSSH.

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