1PAM_SM_CHAUTHTOK(3)            Linux-PAM Manual            PAM_SM_CHAUTHTOK(3)
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NAME

6       pam_sm_chauthtok - PAM service function for authentication token
7       management
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SYNOPSIS

10       #include <security/pam_modules.h>
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12       int pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc,
13                            const char **argv);
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DESCRIPTION

16       The pam_sm_chauthtok function is the service module's implementation of
17       the pam_chauthtok(3) interface.
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19       This function is used to (re-)set the authentication token of the user.
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21       Valid flags, which may be logically OR'd with PAM_SILENT, are:
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23       PAM_SILENT
24           Do not emit any messages.
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26       PAM_CHANGE_EXPIRED_AUTHTOK
27           This argument indicates to the module that the user's
28           authentication token (password) should only be changed if it has
29           expired. This flag is optional and must be combined with one of the
30           following two flags. Note, however, the following two options are
31           mutually exclusive.
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33       PAM_PRELIM_CHECK
34           This indicates that the modules are being probed as to their ready
35           status for altering the user's authentication token. If the module
36           requires access to another system over some network it should
37           attempt to verify it can connect to this system on receiving this
38           flag. If a module cannot establish it is ready to update the user's
39           authentication token it should return PAM_TRY_AGAIN, this
40           information will be passed back to the application.
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42           If the control value sufficient is used in the password stack, the
43           PAM_PRELIM_CHECK section of the modules following that control
44           value is not always executed.
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46       PAM_UPDATE_AUTHTOK
47           This informs the module that this is the call it should change the
48           authorization tokens. If the flag is logically OR'd with
49           PAM_CHANGE_EXPIRED_AUTHTOK, the token is only changed if it has
50           actually expired.
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52       The PAM library calls this function twice in succession. The first time
53       with PAM_PRELIM_CHECK and then, if the module does not return
54       PAM_TRY_AGAIN, subsequently with PAM_UPDATE_AUTHTOK. It is only on the
55       second call that the authorization token is (possibly) changed.
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RETURN VALUES

58       PAM_AUTHTOK_ERR
59           The module was unable to obtain the new authentication token.
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61       PAM_AUTHTOK_RECOVERY_ERR
62           The module was unable to obtain the old authentication token.
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64       PAM_AUTHTOK_LOCK_BUSY
65           Cannot change the authentication token since it is currently
66           locked.
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68       PAM_AUTHTOK_DISABLE_AGING
69           Authentication token aging has been disabled.
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71       PAM_PERM_DENIED
72           Permission denied.
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74       PAM_TRY_AGAIN
75           Preliminary check was unsuccessful. Signals an immediate return to
76           the application is desired.
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78       PAM_SUCCESS
79           The authentication token was successfully updated.
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81       PAM_USER_UNKNOWN
82           User unknown to password service.
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SEE ALSO

85       pam(3), pam_chauthtok(3), pam_sm_chauthtok(3), pam_strerror(3), PAM(8)
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89Linux-PAM                         05/07/2023               PAM_SM_CHAUTHTOK(3)
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