1 /* $OpenBSD: local_passwd.c,v 1.24 2001/12/07 04:15:08 millert Exp $ */ 2 3 /*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #ifndef lint 37 /*static const char sccsid[] = "from: @(#)local_passwd.c 5.5 (Berkeley) 5/6/91";*/ 38 static const char rcsid[] = "$OpenBSD: local_passwd.c,v 1.24 2001/12/07 04:15:08 millert Exp $"; 39 #endif /* not lint */ 40 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <sys/uio.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <pwd.h> 49 #include <stdio.h> 50 #include <signal.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <util.h> 54 #include <login_cap.h> 55 56 static uid_t uid; 57 extern int pwd_gensalt __P((char *, int, struct passwd *, login_cap_t *, char)); 58 extern int pwd_check __P((struct passwd *, login_cap_t *, char *)); 59 extern int pwd_gettries __P((struct passwd *, login_cap_t *)); 60 61 char *getnewpasswd __P((struct passwd *, login_cap_t *, int)); 62 void kbintr __P((int)); 63 64 int 65 local_passwd(uname, authenticated) 66 char *uname; 67 int authenticated; 68 { 69 struct passwd *pw; 70 login_cap_t *lc; 71 sigset_t fullset; 72 time_t period; 73 int i, pfd, tfd = -1; 74 int pwflags = _PASSWORD_OMITV7; 75 76 if (!(pw = getpwnam(uname))) { 77 #ifdef YP 78 extern int use_yp; 79 if (!use_yp) 80 #endif 81 warnx("unknown user %s.", uname); 82 return(1); 83 } 84 if ((lc = login_getclass(pw->pw_class)) == NULL) { 85 warnx("unable to get login class for user %s.", uname); 86 return(1); 87 } 88 89 uid = authenticated ? pw->pw_uid : getuid(); 90 if (uid && uid != pw->pw_uid) { 91 warnx("login/uid mismatch, username argument required."); 92 return(1); 93 } 94 95 /* Get the new password. */ 96 pw->pw_passwd = getnewpasswd(pw, lc, authenticated); 97 98 /* Reset password change time based on login.conf. */ 99 period = login_getcaptime(lc, "passwordtime", 0, 0); 100 if (period > 0) { 101 pw->pw_change = time(NULL) + period; 102 } else { 103 /* 104 * If the pw change time is the same we only need 105 * to update the spwd.db file. 106 */ 107 if (pw->pw_change != 0) 108 pw->pw_change = 0; 109 else 110 pwflags = _PASSWORD_SECUREONLY; 111 } 112 113 /* Drop user's real uid and block all signals to avoid a DoS. */ 114 setuid(0); 115 sigfillset(&fullset); 116 sigdelset(&fullset, SIGINT); 117 sigprocmask(SIG_BLOCK, &fullset, NULL); 118 119 /* Get a lock on the passwd file and open it. */ 120 pw_init(); 121 for (i = 1; (tfd = pw_lock(0)) == -1; i++) { 122 if (i == 4) 123 (void)fputs("Attempting lock password file, " 124 "please wait or press ^C to abort", stderr); 125 (void)signal(SIGINT, kbintr); 126 if (i % 16 == 0) 127 fputc('.', stderr); 128 usleep(250000); 129 (void)signal(SIGINT, SIG_IGN); 130 } 131 if (i >= 4) 132 fputc('\n', stderr); 133 pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); 134 if (pfd < 0 || fcntl(pfd, F_SETFD, 1) == -1) 135 pw_error(_PATH_MASTERPASSWD, 1, 1); 136 137 /* Update master.passwd file and rebuild spwd.db. */ 138 pw_copy(pfd, tfd, pw); 139 if (pw_mkdb(uname, pwflags) < 0) 140 pw_error(NULL, 0, 1); 141 142 return(0); 143 } 144 145 char * 146 getnewpasswd(pw, lc, authenticated) 147 struct passwd *pw; 148 login_cap_t *lc; 149 int authenticated; 150 { 151 char *p; 152 int tries, pwd_tries; 153 char buf[_PASSWORD_LEN+1], salt[_PASSWORD_LEN]; 154 sig_t saveint, savequit; 155 156 saveint = signal(SIGINT, kbintr); 157 savequit = signal(SIGQUIT, kbintr); 158 159 if (!authenticated) { 160 (void)printf("Changing local password for %s.\n", pw->pw_name); 161 if (uid && pw->pw_passwd[0] && 162 strcmp(crypt(getpass("Old password:"), pw->pw_passwd), 163 pw->pw_passwd)) { 164 errno = EACCES; 165 pw_error(NULL, 1, 1); 166 } 167 } 168 169 pwd_tries = pwd_gettries(pw, lc); 170 171 for (buf[0] = '\0', tries = 0;;) { 172 p = getpass("New password:"); 173 if (!*p) { 174 (void)printf("Password unchanged.\n"); 175 pw_error(NULL, 0, 0); 176 } 177 if (strcmp(p, "s/key") == 0) { 178 printf("That password collides with a system feature. Choose another.\n"); 179 continue; 180 } 181 182 if ((tries++ < pwd_tries || pwd_tries == 0) 183 && pwd_check(pw, lc, p) == 0) 184 continue; 185 strlcpy(buf, p, sizeof(buf)); 186 if (!strcmp(buf, getpass("Retype new password:"))) 187 break; 188 (void)printf("Mismatch; try again, EOF to quit.\n"); 189 } 190 if (!pwd_gensalt(salt, _PASSWORD_LEN, pw, lc, 'l')) { 191 (void)printf("Couldn't generate salt.\n"); 192 pw_error(NULL, 0, 0); 193 } 194 (void)signal(SIGINT, saveint); 195 (void)signal(SIGQUIT, savequit); 196 197 return(crypt(buf, salt)); 198 } 199 200 void 201 kbintr(signo) 202 int signo; 203 { 204 char msg[] = "\nPassword unchanged.\n"; 205 struct iovec iv[5]; 206 extern char *__progname; 207 208 iv[0].iov_base = msg; 209 iv[0].iov_len = sizeof(msg) - 1; 210 iv[1].iov_base = __progname; 211 iv[1].iov_len = strlen(__progname); 212 iv[2].iov_base = ": "; 213 iv[2].iov_len = 2; 214 iv[3].iov_base = _PATH_MASTERPASSWD; 215 iv[3].iov_len = sizeof(_PATH_MASTERPASSWD) - 1; 216 iv[4].iov_base = " unchanged\n"; 217 iv[4].iov_len = 11; 218 writev(STDERR_FILENO, iv, 5); 219 220 _exit(1); 221 } 222