I am investigating bcrypt_pbkdf(3) or bcrypt(3) to secure passphrases within an existing application.
However, the man page for bcrypt_pbkdf() does not mention the 72-character password limit that bcrypt() does, especially given bcrypt_pbkdf() appears to accept an output buffer whose length is the caller's choice. 72 characters may seem short, but the application currently concatenates a non-secret global file ID to the passphrase; this can easily make the total length go past 72 characters. I am interested in knowing if I will need to remove the concatenated info from the input. 1. Does the 72-character limit also apply to bcrypt_pbkdf() [presumably this will mean softraid(4) crypto won't accept passwords >72 chars anymore]? 2. What is the recommended buffer size to be passed to bcrypt_pbkdf()? 3. In the BUGS section in the bcrypt(3) man page it mentions that crypt() returns a pointer to static data. Is it safe/smart to assume this constraint also applies to bcrypt() calls? Some assistance clarifying this would be appreciated. Thanks.
