1RPC.YPPASSWDD(8) NIS Reference Manual RPC.YPPASSWDD(8)
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6 rpc.yppasswdd - NIS password update daemon
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9 rpc.yppasswdd [-D directory] -e chsh|chfn [--port number]
10 rpc.yppasswdd [-s shadow] [-p passwd] -e chsh|chfn [--port number]
12 rpc.yppasswdd -x program | -E program -e chsh|chfn [--port number]
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16 rpc.yppasswdd is the RPC server that lets users change their passwords
17 in the presence of NIS (a.k.a. YP). It must be run on the NIS master
18 server for that NIS domain.
19 When a yppasswd(1) client contacts the server, it sends the old user
21 password along with the new one. rpc.yppasswdd will search the
22 system's passwd file for the specified user name, verify that the given
23 (old) password matches, and update the entry. If the user specified
24 does not exist, or if the password, UID or GID doesn't match the
25 information in the password file, the update request is rejected, and
26 an error returned to the client.
27 If this version of the server is compiled with the CHECKROOT=1 option,
29 the password given is also checked against the systems root password.
30 After updating the passwd file and returning a success notification to
32 the client, rpc.yppasswdd executes the pwupdate script that updates the
33 NIS server's passwd.* and shadow.byname maps. This script assumes all
34 NIS maps are kept in directories named /var/yp/nisdomain that each
35 contain a Makefile customized for that NIS domain. If no such Makefile
36 is found, the scripts uses the generic one in /var/yp.
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39 The following options are available:
40 -D directory
42 The passwd and shadow files are located under the specified
43 directory path. rpc.yppasswdd will use this files, not /etc/passwd
44 and /etc/shadow. This is useful if you do not want to give all
45 users in the NIS database automatic access to your NIS server.
46 -E program
48 Instead of rpc.yppasswdd editing the passwd & shadow files, the
49 specified program will be run to do the editing. The following
50 environment variables will be set for the program: YP_PASSWD_OLD,
51 YP_PASSWD_NEW, YP_USER, YP_GECOS, YP_SHELL. The program should
52 return an exit status of 0 if the change completes successfully, 1
53 if the change completes successfully but pwupdate should not be
54 run, and otherwise if the change fails.
55 -p passwdfile
57 This options tells rpc.yppasswdd to use a different source file
58 instead of /etc/passwd This is useful if you do not want to give
59 all users in the NIS database automatic access to your NIS server.
60 -s shadowfile
62 This options tells rpc.yppasswdd to use a different source file
63 instead of /etc/passwd. See below for a brief discussion of shadow
64 support.
65 -e [chsh|chfn]
67 By default, rpc.yppasswdd will not allow users to change the shell
68 or GECOS field of their passwd entry. Using the -e option, you can
69 enable either of these. Note that when enabling support for
70 ypchsh(1), you have to list all shells users are allowed to select
71 in /etc/shells.
72 -x program
74 When the -x option is used, rpc.yppasswdd will not attempt to
75 modify any files itself, but will instead run the specified
76 program, passing to its stdin information about the requested
77 operation(s). There is a defined protocol used to communicate with
78 this external program, which has total freedom in how it propagates
79 the change request. See below for more details on this.
80 -m
82 Will be ignored, for compatibility with Solaris only.
83 --port number
85 rpc.yppasswdd will try to register itself to this port. This makes
86 it possible to have a router filter packets to the NIS ports.
87 -v --version
89 Prints the version number and if this package is compiled with the
90 CHECKROOT option.
91
93 Shadow Passwords
94 Using Shadow passwords alongside NIS does not make too much sense,
95 because the supposedly inaccesible passwords now become readable
96 through a simple invocation of ypcat(1).
97 Shadow support in rpc.yppasswdd does not mean that it offers a very
99 clever solution to this problem, it simply means that it can read and
100 write password entries in the system's shadow file. You have to produce
101 a shadow.byname NIS map to distribute password information to your NIS
102 clients. rpc.yppasswdd will search at first in the /etc/passwd file
103 for the user and password. If it find's the user, but the password is
104 "x" and a /etc/shadow file exists, it will update the password in the
105 shadow map.
106 Use of the -x option
108 The program should expect to read a single line from stdin, which is
109 formatted as follows:
110 <username> o:<oldpass> p:<password> s:<shell> g:<gcos>\n
112 where any of the three fields [p, s, g] may or may not be present.
114 This program should write "OK\n" to stdout if the operation succeeded.
116 On any other result, rpc.yppasswdd will report failure to the client.
117 Note that the program specified by the -x option is responsible for
119 doing any NIS make and build, and for doing any necessary validation on
120 the shell and gcos field information supplied. The password passed to
121 the client will be in UNIX crypt() format.
122 Logging
124 rpc.yppasswdd logs all password update requests to syslogd(8)'s auth
125 facility. The logging information includes the originating host's IP
126 address and the user name and UID contained in the request. The
127 user-supplied password itself is not logged.
128 Security
130 rpc.yppasswdd should be as secure or insecure as any program relying on
131 simple password authentication. If you feel that this is not enough,
132 you may want to protect rpc.yppasswdd from outside access by using the
133 `securenets' feature of the new portmap(8) version 3. Better still,
134 look at rpasswdd(8).
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137 /usr/sbin/rpc.yppasswdd
138 /usr/lib/yp/pwupdate
140 /etc/passwd
142 /etc/shadow
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146 passwd(5), shadow(5), passwd(1), rpasswdd(8), yppasswd(1), ypchsh(1),
147 ypchfn(1), ypserv(8), ypcat(1)
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150 Olaf Kirch <okir@monad.swb.de> and Thorsten Kukuk <kukuk@linux-nis.org>
151NIS Reference Manual 07/29/2020 RPC.YPPASSWDD(8)