Commit | Line | Data |
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252e456d | 1 | #ifndef lint |
9ae20471 | 2 | static char sccsid[] = "@(#)passwd.c 4.6 (Berkeley) %G%"; |
252e456d SL |
3 | #endif |
4 | ||
5 | /* | |
9a59f452 SL |
6 | * Enter a password in the password file. |
7 | * This program should be suid with an owner | |
8 | * with write permission on /etc/passwd. | |
252e456d SL |
9 | */ |
10 | #include <sys/file.h> | |
11 | ||
12 | #include <stdio.h> | |
13 | #include <signal.h> | |
14 | #include <pwd.h> | |
9ae20471 | 15 | #include <ndbm.h> |
252e456d SL |
16 | #include <errno.h> |
17 | ||
8d3b95af | 18 | char temp[] = "/etc/ptmp"; |
252e456d | 19 | char passwd[] = "/etc/passwd"; |
252e456d | 20 | struct passwd *pwd; |
252e456d SL |
21 | char *strcpy(); |
22 | char *crypt(); | |
23 | char *getpass(); | |
24 | char *getlogin(); | |
25 | char *pw; | |
26 | char pwbuf[10]; | |
27 | extern int errno; | |
28 | ||
29 | main(argc, argv) | |
30 | char *argv[]; | |
31 | { | |
32 | char *p; | |
33 | int i; | |
34 | char saltc[2]; | |
35 | long salt; | |
36 | int u; | |
37 | int insist; | |
38 | int ok, flags; | |
39 | int c, pwlen, fd; | |
40 | FILE *tf; | |
41 | char *uname; | |
9ae20471 | 42 | DBM *dp; |
252e456d SL |
43 | |
44 | insist = 0; | |
45 | if (argc < 2) { | |
46 | if ((uname = getlogin()) == NULL) { | |
47 | printf ("Usage: passwd user\n"); | |
48 | exit(1); | |
49 | } | |
50 | printf("Changing password for %s\n", uname); | |
51 | } else | |
52 | uname = argv[1]; | |
8d3b95af | 53 | pwd = getpwnam(uname); |
252e456d SL |
54 | u = getuid(); |
55 | if (pwd == NULL || (u != 0 && u != pwd->pw_uid)) { | |
56 | printf("Permission denied.\n"); | |
57 | exit(1); | |
58 | } | |
252e456d SL |
59 | if (pwd->pw_passwd[0] && u != 0) { |
60 | strcpy(pwbuf, getpass("Old password:")); | |
61 | pw = crypt(pwbuf, pwd->pw_passwd); | |
62 | if (strcmp(pw, pwd->pw_passwd) != 0) { | |
63 | printf("Sorry.\n"); | |
64 | exit(1); | |
65 | } | |
66 | } | |
67 | tryagain: | |
68 | strcpy(pwbuf, getpass("New password:")); | |
69 | pwlen = strlen(pwbuf); | |
70 | if (pwlen == 0) { | |
71 | printf("Password unchanged.\n"); | |
72 | exit(1); | |
73 | } | |
74 | /* | |
75 | * Insure password is of reasonable length and | |
76 | * composition. If we really wanted to make things | |
77 | * sticky, we could check the dictionary for common | |
78 | * words, but then things would really be slow. | |
79 | */ | |
80 | ok = 0; | |
81 | flags = 0; | |
82 | p = pwbuf; | |
83 | while (c = *p++) { | |
84 | if (c >= 'a' && c <= 'z') | |
85 | flags |= 2; | |
86 | else if (c >= 'A' && c <= 'Z') | |
87 | flags |= 4; | |
88 | else if (c >= '0' && c <= '9') | |
89 | flags |= 1; | |
90 | else | |
91 | flags |= 8; | |
92 | } | |
93 | if (flags >= 7 && pwlen >= 4) | |
94 | ok = 1; | |
95 | if ((flags == 2 || flags == 4) && pwlen >= 6) | |
96 | ok = 1; | |
97 | if ((flags == 3 || flags == 5 || flags == 6) && pwlen >= 5) | |
98 | ok = 1; | |
99 | if (!ok && insist < 2) { | |
252e456d SL |
100 | printf("Please use %s.\n", flags == 1 ? |
101 | "at least one non-numeric character" : | |
102 | "a longer password"); | |
103 | insist++; | |
104 | goto tryagain; | |
105 | } | |
106 | if (strcmp(pwbuf, getpass("Retype new password:")) != 0) { | |
107 | printf("Mismatch - password unchanged.\n"); | |
108 | exit(1); | |
109 | } | |
110 | time(&salt); | |
111 | salt = 9 * getpid(); | |
112 | saltc[0] = salt & 077; | |
113 | saltc[1] = (salt>>6) & 077; | |
114 | for (i = 0; i < 2; i++) { | |
115 | c = saltc[i] + '.'; | |
116 | if (c > '9') | |
117 | c += 7; | |
118 | if (c > 'Z') | |
119 | c += 6; | |
120 | saltc[i] = c; | |
121 | } | |
122 | pw = crypt(pwbuf, saltc); | |
123 | signal(SIGHUP, SIG_IGN); | |
124 | signal(SIGINT, SIG_IGN); | |
125 | signal(SIGQUIT, SIG_IGN); | |
643bb829 | 126 | (void) umask(0); |
9a59f452 | 127 | fd = open(temp, O_WRONLY|O_CREAT|O_EXCL, 0644); |
252e456d SL |
128 | if (fd < 0) { |
129 | fprintf(stderr, "passwd: "); | |
9a59f452 | 130 | if (errno == EEXIST) |
252e456d SL |
131 | fprintf(stderr, "password file busy - try again.\n"); |
132 | else | |
133 | perror(temp); | |
134 | exit(1); | |
135 | } | |
136 | signal(SIGTSTP, SIG_IGN); | |
137 | if ((tf = fdopen(fd, "w")) == NULL) { | |
138 | fprintf(stderr, "passwd: fdopen failed?\n"); | |
139 | exit(1); | |
140 | } | |
9ae20471 RC |
141 | if ((dp = ndbmopen(passwd, O_RDWR, 0644)) == NULL) { |
142 | fprintf(stderr, "Warning: dbminit failed: "); | |
143 | perror(passwd); | |
144 | } else if (flock(dp->db_dirf, LOCK_EX) < 0) { | |
145 | perror("Warning: lock failed"); | |
146 | ndbmclose(dp); | |
147 | dp = NULL; | |
148 | } | |
252e456d SL |
149 | /* |
150 | * Copy passwd to temp, replacing matching lines | |
151 | * with new password. | |
152 | */ | |
153 | while ((pwd = getpwent()) != NULL) { | |
8d3b95af | 154 | if (strcmp(pwd->pw_name, uname) == 0) { |
252e456d SL |
155 | if (u && u != pwd->pw_uid) { |
156 | fprintf(stderr, "passwd: permission denied.\n"); | |
8d3b95af | 157 | goto out; |
252e456d SL |
158 | } |
159 | pwd->pw_passwd = pw; | |
160 | if (pwd->pw_gecos[0] == '*') | |
161 | pwd->pw_gecos++; | |
9ae20471 | 162 | replace(dp, pwd); |
252e456d SL |
163 | } |
164 | fprintf(tf,"%s:%s:%d:%d:%s:%s:%s\n", | |
165 | pwd->pw_name, | |
166 | pwd->pw_passwd, | |
167 | pwd->pw_uid, | |
168 | pwd->pw_gid, | |
169 | pwd->pw_gecos, | |
170 | pwd->pw_dir, | |
171 | pwd->pw_shell); | |
172 | } | |
173 | endpwent(); | |
9ae20471 RC |
174 | (void) fclose(tf); |
175 | ndbmclose(dp); | |
176 | if (rename(temp, passwd) < 0) { | |
8d3b95af | 177 | fprintf(stderr, "passwd: "), perror("rename"); |
9ae20471 RC |
178 | out: |
179 | unlink(temp); | |
180 | exit(1); | |
181 | } | |
182 | exit(0); | |
8d3b95af RC |
183 | } |
184 | ||
9ae20471 RC |
185 | /* |
186 | * Replace the password entry in the dbm data base with pwd. | |
187 | */ | |
188 | replace(dp, pwd) | |
189 | DBM *dp; | |
190 | struct passwd *pwd; | |
8d3b95af | 191 | { |
9ae20471 RC |
192 | datum key, content; |
193 | register char *cp, *tp; | |
194 | char buf[BUFSIZ]; | |
8d3b95af | 195 | |
9ae20471 RC |
196 | if (dp == NULL) |
197 | return; | |
198 | ||
199 | cp = buf; | |
200 | #define COMPACT(e) tp = pwd->pw_/**/e; while (*cp++ = *tp++); | |
201 | COMPACT(name); | |
202 | COMPACT(passwd); | |
203 | *(int *)cp = pwd->pw_uid; cp += sizeof (int); | |
204 | *(int *)cp = pwd->pw_gid; cp += sizeof (int); | |
205 | *(int *)cp = pwd->pw_quota; cp += sizeof (int); | |
206 | COMPACT(comment); | |
207 | COMPACT(gecos); | |
208 | COMPACT(dir); | |
209 | COMPACT(shell); | |
210 | content.dptr = buf; | |
211 | content.dsize = cp - buf; | |
212 | key.dptr = pwd->pw_name; | |
213 | key.dsize = strlen(pwd->pw_name); | |
214 | dbmstore(dp, key, content, DB_REPLACE); | |
215 | key.dptr = (char *)&pwd->pw_uid; | |
216 | key.dsize = sizeof (int); | |
217 | dbmstore(dp, key, content, DB_REPLACE); | |
252e456d | 218 | } |