Because it is easy to extract strings from an application source code or binary, secrets should not be hard-coded. This is particularly true for
applications that are distributed or that are open-source.
In the past, it has led to the following vulnerabilities:
Secrets should be stored outside of the source code in a configuration file or a management service for secrets.
This rule detects variables/fields having a name matching a list of words (secret, token, credential, auth, api[_.-]?key) being assigned a
pseudorandom hard-coded value. The pseudorandomness of the hard-coded value is based on its entropy and the probability to be human-readable. The
randomness sensibility can be adjusted if needed. Lower values will detect less random values, raising potentially more false positives.
Ask Yourself Whether
- The secret allows access to a sensitive component like a database, a file storage, an API, or a service.
- The secret is used in a production environment.
- Application re-distribution is required before updating the secret.
There would be a risk if you answered yes to any of those questions.
Recommended Secure Coding Practices
- Store the secret in a configuration file that is not pushed to the code repository.
- Use your cloud provider’s service for managing secrets.
- If a secret has been disclosed through the source code: revoke it and create a new one.
Sensitive Code Example
$secret = '47828a8dd77ee1eb9dde2d5e93cb221ce8c32b37';
MyClass->callMyService($secret);
Compliant Solution
Using AWS Secrets Manager:
use Aws\SecretsManager\SecretsManagerClient;
use Aws\Exception\AwsException;
$client = new SecretsManagerClient(...);
$secretName = 'example';
doSomething($client, $secretName)
function doSomething($client, $secretName) {
try {
$result = $client->getSecretValue([
'SecretId' => $secretName,
]);
} catch (AwsException $e) {
...
}
if (isset($result['SecretString'])) {
$secret = $result['SecretString'];
} else {
$secret = base64_decode($result['SecretBinary']);
}
// do something with the secret
MyClass->callMyService($secret);
}
See
