Auth Sasl Laravel Package

Getting Started

pear/auth_sasl is a low-level PEAR library, not a Laravel package. It has no service provider, facade, config file, or Laravel integration. Treat it as a narrow utility for generating SASL authentication responses when you must speak a legacy protocol directly.

Minimal steps:

1. Install it:

   composer require pear/auth_sasl
   

2. Verify Composer autoloading. PEAR packages use legacy underscore class names such as Auth_SASL and Auth_SASL_DigestMD5:

   php artisan tinker
   

   class_exists(\Auth_SASL::class); // true
   

3. Look first at:

   • vendor/pear/auth_sasl/Auth/SASL.php — the factory() switch and supported mechanism names.
   • vendor/pear/auth_sasl/Auth/SASL/*.php — each mechanism’s getResponse() signature. They are not identical.
   • vendor/composer/autoload_classmap.php if the class is not found.

4. First real use case: authenticating against a legacy SMTP/IMAP service that requires a mechanism Laravel/Symfony Mailer does not expose, or generating a SASL token for a diagnostic command. For example, a basic PLAIN response:

   $sasl = \Auth_SASL::factory('PLAIN');
   
   if (!is_object($sasl) || !method_exists($sasl, 'getResponse')) {
       throw new RuntimeException('SASL mechanism unavailable');
   }
   
   $token = $sasl->getResponse([
       'authcid' => config('mail.mailers.smtp.username'),
       'authzid' => '',
   ], config('mail.mailers.smtp.password'));
   

Do not reach for this package for ordinary Laravel mail. Symfony Mailer already handles PLAIN, LOGIN, CRAM-MD5, and XOAUTH2. Use pear/auth_sasl only when you need a mechanism Symfony does not provide, or when maintaining an integration that already depends on PEAR’s Net_SMTP.

Implementation Patterns

Wrap it behind an application service. Do not call Auth_SASL::factory() throughout controllers or jobs. Isolate mechanism-specific signatures and PEAR error handling:

namespace App\Support;

final class SaslAuthenticator
{
    public function plain(string $username, string $password, string $authzid = ''): string
    {
        return $this->factory('PLAIN')->getResponse([
            'authcid' => $username,
            'authzid' => $authzid,
        ], $password);
    }

    public function cramMd5(string $challenge, string $username, string $password): string
    {
        return $this->factory('CRAM-MD5')->getResponse(
            $challenge,
            ['authcid' => $username],
            $password
        );
    }

    private function factory(string $mechanism): object
    {
        $sasl = \Auth_SASL::factory($mechanism);

        if (!is_object($sasl) || !method_exists($sasl, 'getResponse')) {
            throw new \RuntimeException("Unsupported SASL mechanism [{$mechanism}]");
        }

        return $sasl;
    }
}

Bind this in a service provider if you use it in multiple places. This also gives you a seam to replace Auth_SASL later with a maintained SCRAM/SASL implementation.

Use it in a custom Symfony Mailer authenticator. If you need DIGEST-MD5 or NTLM for an SMTP server, implement Symfony\Component\Mailer\Transport\Smtp\Auth\AuthenticatorInterface and call Auth_SASL from authenticate(). Register the authenticator on an EsmtpTransport instance or from a custom transport factory. This keeps Laravel’s mail API intact while extending only the authentication step.

Use it in a legacy PEAR stack. If an existing project uses pear/net_smtp or pear/mail, Auth_SASL is already a transitive dependency. Configure the mechanism through Net_SMTP rather than calling Auth_SASL directly, unless you need to debug the token flow.

Build a reusable protocol health check. An Artisan command that connects to an SMTP server, reads the EHLO AUTH capabilities, chooses the strongest mutually supported mechanism, and generates a response with Auth_SASL is a practical diagnostic tool. Keep credentials in config and redact tokens from output.

Test with known vectors. PLAIN and LOGIN are easy to assert exactly. CRAM-MD5 has stable RFC test vectors. DIGEST-MD5 and NTLM are stateful and may include a random client nonce, so assert protocol flow and response structure rather than exact bytes unless you can inject deterministic values.

Create one instance per authentication session. Challenge-response mechanisms can retain challenge/state internally. Do not register a configured Auth_SASL object as a singleton and reuse it across users or connections.

Gotchas and Tips

• PEAR errors are not exceptions. Auth_SASL::factory() can return a PEAR_Error object for an unknown mechanism. PHP try/catch will not catch it. Check PEAR::isError() if PEAR core is available, or at minimum check is_object($sasl) and method_exists($sasl, 'getResponse').
• getResponse() signatures vary by mechanism. PLAIN and LOGIN generally take ($authData, $password). CRAM-MD5, DIGEST-MD5, and NTLM are challenge-response and generally take ($challenge, $authData, $password). Always read the concrete mechanism class before integrating.
• LOGIN returns two lines. Auth_SASL_Login commonly returns base64 username and base64 password separated by \r\n, not one SMTP token. If you send it as a single AUTH response, the server may reject it. Split and send each line in response to the appropriate 334 challenge.
• Do not double-encode. Most mechanisms return a base64 token ready for the protocol. If your transport also base64-encodes responses, authentication will fail.
• CRAM-MD5 challenge handling. Pass the server challenge in the form expected by the mechanism class. In practice the class base64-decodes it internally, so preserve the server’s base64 challenge string rather than decoding it yourself.
• DIGEST-MD5 is not a one-call flow. It is stateful, depends on realm/nonce/cnonce/qop values, and may require rspauth verification. Treat it as a multi-step protocol, not a drop-in token generator.
• Use TLS. PLAIN and LOGIN are base64, not encryption. Never send them over plaintext SMTP. Avoid logging passwords, challenges, or generated tokens; Laravel’s debug logging can accidentally capture them.
• Prefer modern mechanisms. CRAM-MD5 and DIGEST-MD5 are deprecated or weak by modern standards. If the server supports SCRAM-SHA-256, verify whether this package supports it; if not, use a maintained SASL/SCRAM library instead.
• Autoloading can be a problem. These are legacy global classes. If class_exists('Auth_SASL') is false after install, run composer dump-autoload and inspect Composer’s classmap. Avoid editing files under vendor/; if necessary, add a small bootstrap that requires the package’s Auth/SASL.php from a known path.
• Default mechanism is surprising. Calling Auth_SASL::factory() without an argument may default to DIGEST-MD5. Always pass the mechanism explicitly.
• Mechanism names are specific. Use names such as 'PLAIN', 'LOGIN', 'CRAM-MD5', 'DIGEST-MD5', and 'NTLM' as expected by the factory switch. The factory normalizes case, but the mechanism must still be supported by the installed version.
• No Laravel config or container integration. Keep credentials in config/mail.php or your own config file. Wrap the package in your own adapter so you can swap it for Symfony authenticators or another library without touching call sites.
• Maintenance risk. This is an old, low-activity PEAR package. Pin the version in composer.json, run your test suite on the target PHP version, and watch for deprecation notices. The package is safest as a temporary compatibility adapter, not a core dependency.