Password Strength Meter
by Eric Montgomery
This utility aims to make it easy to determine and categorize the complexity of a password, hopefully simplifying writing validators for setting account passwords. By allowing or disallowing a password to be set based on its complexity alone, you remove the need for arbitrary restrictions like "must contain at least one upper-case letter and one number", "must contain at least one non-alphanumeric symbol", etc. This allows users to more freely choose passwords that fit their preferences while still enforcing some minimum level of security.
Password length also becomes less of an issue. For instance, the password "ئЖjΩ
Get an instance of the
PasswordStrengthMeter class and then use the
PasswordStrengthMeter passwordStrengthMeter = PasswordStrengthMeter.getInstance(); boolean passwordSecure = passwordStrengthMeter.satisfiesStrengthClass( "pAssword123", PasswordStrengthClass.LENGTH_10_MIXED_CASE_WITH_NUMBER);
You can also get the number of iterations it would take to guess the given password. Example:
BigInteger result = passwordStrengthMeter.iterationCount("pAssword123");
(Note that the iteration count assumes a naive, sequential approach to password generation. A brute force password utility may generate its guesses more effectively, i.e. by using statistical models or dictionary word lists, and so may be able to reach the password more quickly than the result indicates.)
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.
In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.
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