PWAUTH(8) System Manager's Manual PWAUTH(8)NAME
pwauth - authenticator for mod_authnz_external and the Apache HTTP Daemon
SYNOPSIS
pwauth
DESCRIPTION
Pwauth is an authenticator designed to be used with mod_auth_external or mod_authnz_external and the Apache HTTP Daemon to support reason-
ably secure web authentication out of the system password database on most versions of Unix. Particulary - secure authentication against
PAM.
The simplest test pwauth is to start a root shell and just run pwauth. It will attempt to read the login and password from standard input,
so type a login name, hit return, then type a password, and hit return (the password will echo on your screen). The check the status code
that was returned (in csh: "echo $status" in sh: "echo $?").
If the login/password were correct you should get a zero status code. If not, you will get some other value. See below the list of status
codes to find the meaning of the various values returned. Any values 50 or greater indicate a configuration error.
STATUS CODES
0 STATUS_OK
Login OK.
1 STATUS_UNKNOWN
Nonexistant login or (for some configurations) incorrect password.
2 STATUS_INVALID
Incorrect password (for some configurations).
3 STATUS_BLOCKED
Uid number is below MIN_UNIX_UID value configured in config.h.
4 STATUS_EXPIRED
Login ID has expired.
5 STATUS_PW_EXPIRED
Login's password has expired.
6 SSTATUS_NOLOGIN
Logins to system have been turned off (usually by /etc/nologin file).
7 STATUS_MANYFAILES
Limit on number of bad logins exceeded.
50 STATUS_INT_USER
pwauth was invoked by a uid not on the SERVER_UIDS list. If you get this error code, you probably have SERVER_UIDS set incorrectly
in pwauth's config.h file.
51 STATUS_INT_ARGS
pwauth was not given a login & password to check. The means the passing of data from mod_auth_external to pwauth is messed up. Most
likely one is trying to pass data via environment variables, while the other is trying to pass data via a pipe.
52 STATUS_INT_ERR
one of several rare and unlikely internal errors occurred. You'll have to read the source code to figure these out.
53 STATUS_INT_NOROOT
pwauth was not able to read the password database. Usually this means it is not running as root. (PAM and login.conf configurations
will return 1 in this case.)
AUTHOR
pwauth was written by Jan Wolter <jan@unixpapa.com>.
This manual page was written by Hai Zaar <haizaar@haizaar.com>, for the Debian project (but may be used by others).
2009-05-02 PWAUTH(8)
Check Out this Related Man Page
authenticate_user(3x)authenticate_user(3x)Name
authenticate_user - authenticate user
Syntax
#include <pwd.h>
#include <auth.h> /* For error codes */
int authenticate_user(user, password, line)
struct passwd *user;
char *password;
char *line;
Arguments
user
A pointer to the passwd entry.
password
A pointer to the password.
line
The name of the terminal line as it is listed in the file.
Description
The routine authenticates a user name or UID against a supplied password and returns a nonnegative integer on success. The value returned
is the number of failed login authentication attempts since the last successful login authentication (or zero if this feature is not
enabled). This routine is found in the library and loaded with the -lauth option.
At all security levels higher than BSD, the login fail count in the auth database is incremented if authentication fails, and cleared if it
succeeds. In addition, the account must be marked enabled for logins as defined by the Account Mask value for A_LOGIN. See for informa-
tion about the Account Mask values.
If a non-NULL value is supplied for the argument and the argument is not the empty string, the function also verifies that the specified
user is allowed access through that line. In particular, accounts with a UID equal to zero will return success only if the specified line
is marked secure in the file.
Restrictions
The process must have read access to the auth database to authenticate users in a secure environment.
The process must have read/write access to the auth database to update the authentication fail count.
If auth information is being served through BIND, the process is required to obtain a Kerberos ticket for that service before invoking this
function.
Example
extern int errno;
struct passwd *pwd;
int status;
pwd = getpwnam("root");
status = authenticate_user(pwd, "rootpass", "/dev/console");
if(status < 0)
if(errno == EPERM)
puts("Login failed");
else
perror("authenticate_user");
else
if(status > 0)
printf("%d failed attempts
", status);
Return Values
When successful, the routine returns the number of failed login authentication attempts since last successful login authentication.
When an error occurs, errno is set and a negative error code is returned. The error code returned may be the same as errno or it may be an
extended error code defined in
Diagnostics
On error return errno may be set to one of the following values:
[EPERM] Either the password is incorrect, the password is expired, the specified line needs to be secure and is not, or the
account is disabled and a login authentication is required.
[EINVAL] No authentication information for user.
[ENOSYS] Security subsystem not configured correctly.
[EACCES] Process does not have read access to the necessary information.
On error return the return value may be the same as errno or, if errno is [EPERM], it may be one of the following additional values defined
in
[A_EBADPASS] The supplied password was incorrect.
[A_ESOFTEXP] The account's password expired recently.
[A_EHARDEXP] The account's password expired quite some time ago.
[A_ENOLOGIN] The account is not enabled.
[A_EOPENLINE] The account requires a secure line and the specified line was not marked that way in the file.
FilesEnvironment
If the system is operating in the BSD security level, the password expiration, login fail count, and account disabling features are not
available (and therefore are not used in authentication computations).
See Alsogetauthent(3x), getpwent(3), auth(5), passwd(5yp), ttys(5)authenticate_user(3x)