* The `module_constraints` function should return the minimum and maximum length of the password, salt and the combination of password and salt in following order: password (pure), salt (pure), password (optimized), salt (optimized) and combination (optimized).
Each pair should be set to -1 if the hash mode is not supporting theappropriate field. For example, if a hash-mode does not support a salt, it should be set to -1. The last field (combination) is important if the password and the salt is stored in the same buffer in the kernel (typically raw hashes only).
* The first parameter to `module_generate_hash` is the password, which can be either in ASCII or binary (packed) form. The second parameter is the salt *which can be undefined for unsalted hash modes).
During `single` and `passthrough` tests the `module_generate_hash` function must provide random values (e.g. salt) for hash generation if necessary. The test.pl script offers a few handy functions like `random_hex_string`, `random_numeric_string` and `random_bytes`. You can implement your own salt generation functions, if your mode has specific requirements.
During `verify` tests the `module_verify_hash` function must parse the hash:password line and calculate a hash by passing all necessary data to `module_generate_hash`. How you pass it is up to you, as long as the first parameter is the password.
**Important**: You have to call `pack_if_HEX_notation` as soon as you have parsed the password, or your tests will fail on passwords in the `$HEX[...]` format.
If the algorithm has ambiguous hashes (e.g. partial case-insensitivity), the test module can provide an optional function `module_preprocess_hashlist`. It receives a reference to the hashlist array and can unify the hashes in a way that guarantees the match with the output of `module_verify_hash`.
