Currently we trust the LDAP server to only return the `yubi_attr`
attribute, yet we loop over all possible attributes when there should
only be one.
Since the bundled test LDAP server ignores the requested attributes list,
we must make sure to only match against the `yubi_attr` attibute as
opposed to "all of them".
This also fixes an issue where AUTH_NOT_FOUND was returned instead
of AUTH_NO_TOKENS when there were no values returned for `yubi_attr`
but another attribute's value was considered as a candidate token.
Currently, if a user has no associated tokens, we still prompt for an
OTP challenge and attempt to verify it.
This adds a check earlier to avoid the useless prompt in that case.
The `nullok` option is also added. It changes the return value from
PAM_USER_UNKNOWN to PAM_IGNORE. (fixes#97)
Finally, some constants have been turned to symbolic form for clarity
and debugging output is improved.
When using `try_first_pass` or `use_first_pass`, the password we inherit
from PAM might not actually be an OTP challenge.
Currently, we happily leak it to the validation server without first
checking if it matches an authorized token ID.
This postpones sending the actual request until we know the token ID is
authorized.
The previous instructions create a global word-writeable path for challenge files. This is a security issue because all users and unprivileged processes can create challenge files for arbitrary users. This enables an attacker to bypass the second factor for authentication.
add a debug_file option for where to write debug info (default to stdout)
stop compiling with DEBUG_PAM and PAM_DEBUG
make debugging behave the same way on linux-pam and openpam
