decryptValue method
Decrypts a config value produced by encryptValue (or encrypted at rest
in env files). Values MUST carry the ENC: prefix: any non-empty value
without it throws a FormatException — plaintext values are not
supported. An empty value is returned unchanged.
When failOnInvalid is false, values that cannot be decrypted (missing
the ENC: prefix, malformed base64, or failing GCM authentication) are
returned unchanged instead of throwing. Use this for values sourced from
systems that may still deliver plaintext (e.g. remote config flags).
Implementation
String decryptValue(String value, {bool failOnInvalid = true}) =>
decodeConfigValue(value, failOnInvalid: failOnInvalid);