slackhq/nebula · error

error while verifying certificate %+v: %w

Error message

error while verifying certificate %+v: %w

What it means

Catch-all diagnostic wrapper in nebula-cert verify: VerifyCertificate failed with something other than ErrCaNotFound (expired cert, bad signature, blocklisted, fingerprint mismatch, etc.). The full certificate details are rendered with %+v and the underlying error preserved via %w.

Source

Thrown at cmd/nebula-cert/verify.go:81

		return fmt.Errorf("unable to read crt: %w", err)
	}
	var errs []error
	for {
		if len(rawCert) == 0 {
			break
		}
		c, extra, err := cert.UnmarshalCertificateFromPEM(rawCert)
		if err != nil {
			return fmt.Errorf("error while parsing crt: %w", err)
		}
		rawCert = extra
		_, err = caPool.VerifyCertificate(time.Now(), c)
		if err != nil {
			switch {
			case errors.Is(err, cert.ErrCaNotFound):
				errs = append(errs, fmt.Errorf("error while verifying certificate v%d %s with issuer %s: %w", c.Version(), c.Name(), c.Issuer(), err))
			default:
				errs = append(errs, fmt.Errorf("error while verifying certificate %+v: %w", c, err))
			}
		}
	}

	return errors.Join(errs...)
}

func verifySummary() string {
	return "verify <flags>: verifies a certificate isn't expired and was signed by a trusted authority."
}

func verifyHelp(out io.Writer) {
	vf := newVerifyFlags()
	_, _ = out.Write([]byte("Usage of " + os.Args[0] + " " + verifySummary() + "\n"))
	_, _ = out.Write([]byte(stdioHelpText))
	vf.set.SetOutput(out)
	vf.set.PrintDefaults()
}

View on GitHub (pinned to dd8f660c0a)

Solutions

1. Read the wrapped error to identify the concrete failure (expiry, signature, block list)
2. Renew or re-sign the certificate as appropriate
3. Ensure the CA pool contains the correct, valid CAs

When it happens

Trigger: Thrown at cmd/nebula-cert/verify.go:81 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• SSL/TLS and certificate errors — how TLS handshakes and certificate validation fail.

AI-assisted analysis of slackhq/nebula@dd8f660c0a (2026-09-03). Data as JSON: /api/errors/a78500d44683b7cb. Report an issue: GitHub.