Password mask is a template defining allowed characters for each position of the password
candidates. The mask has the form of a string containing one or more symbols. A password mask m
of length n is defined as:
m = s1 s2 … sn
Obviously, the candidate passwords has the same length n as the mask. The meaning of symbol in the mask is:
| symbol | description | characters in set |
| ?l | lowercase Latin letters | abcdefghijklmnopqrstuvwxyz |
| ?u | uppercase Latin letters | ABCDEFGHIJKLMNOPQRSTUVWXYZ |
| ?d | digits | 0123456789 |
| ?s | special characters | (space)!”#$%&’()*+,-./ :;<=>?@[\]^_‘{|}~ |
| ?h | hexadecimal digits with small letters | 0123456789abcdef |
| ?H | hexadecimal digits with big letters | 0123456789ABCDEF |
| ?a | all standard ASCII characters: ?l, ?u, ?d, ?s | |
| ?b | binary – all bytes with values between 0x00 and 0xFF | |
| ?1 | user-defined character set no. 1 | |
| ?2 | user-defined character set no. 2 | |
| ?3 | user-defined character set no. 3 | |
| ?4 | user-defined character set no. 4 |