| File: | src/libexec/login_lchpass/../../usr.bin/passwd/local_passwd.c |
| Warning: | line 131, column 2 The return value from the call to 'setuid' is not checked. If an error occurs in 'setuid', the following code may execute with unexpected privileges |
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| 1 | /* $OpenBSD: local_passwd.c,v 1.62 2021/10/24 21:24:17 deraadt 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. Neither the name of the University nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | * SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | #include <sys/types.h> |
| 33 | #include <sys/stat.h> |
| 34 | #include <sys/uio.h> |
| 35 | |
| 36 | #include <err.h> |
| 37 | #include <errno(*__errno()).h> |
| 38 | #include <fcntl.h> |
| 39 | #include <paths.h> |
| 40 | #include <pwd.h> |
| 41 | #include <stdio.h> |
| 42 | #include <stdlib.h> |
| 43 | #include <signal.h> |
| 44 | #include <string.h> |
| 45 | #include <unistd.h> |
| 46 | #include <util.h> |
| 47 | #include <login_cap.h> |
| 48 | #include <readpassphrase.h> |
| 49 | |
| 50 | #define UNCHANGED_MSG"Password unchanged." "Password unchanged." |
| 51 | |
| 52 | static uid_t uid; |
| 53 | extern int pwd_check(login_cap_t *, char *); |
| 54 | extern int pwd_gettries(login_cap_t *); |
| 55 | |
| 56 | int local_passwd(char *, int); |
| 57 | char *getnewpasswd(struct passwd *, login_cap_t *, int); |
| 58 | void kbintr(int); |
| 59 | |
| 60 | int |
| 61 | local_passwd(char *uname, int authenticated) |
| 62 | { |
| 63 | struct passwd *pw, *opw; |
| 64 | login_cap_t *lc; |
| 65 | sigset_t fullset; |
| 66 | time_t period; |
| 67 | int i, pfd, tfd = -1; |
| 68 | int pwflags = _PASSWORD_OMITV70x02; |
| 69 | |
| 70 | if (!(pw = getpwnam_shadow(uname))) { |
| 71 | warnx("unknown user %s.", uname); |
| 72 | return(1); |
| 73 | } |
| 74 | |
| 75 | if (unveil(_PATH_MASTERPASSWD_LOCK"/etc/ptmp", "rwc") == -1) |
| 76 | err(1, "unveil %s", _PATH_MASTERPASSWD_LOCK"/etc/ptmp"); |
| 77 | if (unveil(_PATH_MASTERPASSWD"/etc/master.passwd", "r") == -1) |
| 78 | err(1, "unveil %s", _PATH_MASTERPASSWD"/etc/master.passwd"); |
| 79 | if (unveil(_PATH_LOGIN_CONF"/etc/login.conf", "r") == -1) |
| 80 | err(1, "unveil %s", _PATH_LOGIN_CONF"/etc/login.conf"); |
| 81 | if (unveil(_PATH_LOGIN_CONF"/etc/login.conf" ".db", "r") == -1) |
| 82 | err(1, "unveil %s.db", _PATH_LOGIN_CONF"/etc/login.conf"); |
| 83 | if (unveil(_PATH_BSHELL"/bin/sh", "x") == -1) |
| 84 | err(1, "unveil %s", _PATH_BSHELL"/bin/sh"); |
| 85 | if (unveil(_PATH_SHELLS"/etc/shells", "r") == -1) |
| 86 | err(1, "unveil %s", _PATH_SHELLS"/etc/shells"); |
| 87 | if (unveil(_PATH_PWD_MKDB"/usr/sbin/pwd_mkdb", "x") == -1) |
| 88 | err(1, "unveil %s", _PATH_PWD_MKDB"/usr/sbin/pwd_mkdb"); |
| 89 | if (pledge("stdio rpath wpath cpath getpw tty id proc exec", NULL((void *)0)) == -1) |
| 90 | err(1, "pledge"); |
| 91 | |
| 92 | if ((opw = pw_dup(pw)) == NULL((void *)0)) { |
| 93 | warn(NULL((void *)0)); |
| 94 | return(1); |
| 95 | } |
| 96 | if ((lc = login_getclass(pw->pw_class)) == NULL((void *)0)) { |
| 97 | warnx("unable to get login class for user %s.", uname); |
| 98 | free(opw); |
| 99 | return(1); |
| 100 | } |
| 101 | |
| 102 | uid = authenticated ? pw->pw_uid : getuid(); |
| 103 | if (uid && uid != pw->pw_uid) { |
| 104 | warnx("login/uid mismatch, username argument required."); |
| 105 | free(opw); |
| 106 | return(1); |
| 107 | } |
| 108 | |
| 109 | /* Get the new password. */ |
| 110 | pw->pw_passwd = getnewpasswd(pw, lc, authenticated); |
| 111 | |
| 112 | if (pledge("stdio rpath wpath cpath getpw id proc exec", NULL((void *)0)) == -1) |
| 113 | err(1, "pledge"); |
| 114 | |
| 115 | /* Reset password change time based on login.conf. */ |
| 116 | period = (time_t)login_getcaptime(lc, "passwordtime", 0, 0); |
| 117 | if (period > 0) { |
| 118 | pw->pw_change = time(NULL((void *)0)) + period; |
| 119 | } else { |
| 120 | /* |
| 121 | * If the pw change time is the same we only need |
| 122 | * to update the spwd.db file. |
| 123 | */ |
| 124 | if (pw->pw_change != 0) |
| 125 | pw->pw_change = 0; |
| 126 | else |
| 127 | pwflags = _PASSWORD_SECUREONLY0x01; |
| 128 | } |
| 129 | |
| 130 | /* Drop user's real uid and block all signals to avoid a DoS. */ |
| 131 | setuid(0); |
The return value from the call to 'setuid' is not checked. If an error occurs in 'setuid', the following code may execute with unexpected privileges | |
| 132 | sigfillset(&fullset); |
| 133 | sigdelset(&fullset, SIGINT2); |
| 134 | sigprocmask(SIG_BLOCK1, &fullset, NULL((void *)0)); |
| 135 | |
| 136 | if (pledge("stdio rpath wpath cpath proc exec", NULL((void *)0)) == -1) |
| 137 | err(1, "pledge"); |
| 138 | |
| 139 | /* Get a lock on the passwd file and open it. */ |
| 140 | pw_init(); |
| 141 | for (i = 1; (tfd = pw_lock(0)) == -1; i++) { |
| 142 | if (i == 4) |
| 143 | (void)fputs("Attempting to lock password file, " |
| 144 | "please wait or press ^C to abort", stderr(&__sF[2])); |
| 145 | (void)signal(SIGINT2, kbintr); |
| 146 | if (i % 16 == 0) |
| 147 | fputc('.', stderr(&__sF[2])); |
| 148 | usleep(250000); |
| 149 | (void)signal(SIGINT2, SIG_IGN(void (*)(int))1); |
| 150 | } |
| 151 | if (i >= 4) |
| 152 | fputc('\n', stderr(&__sF[2])); |
| 153 | pfd = open(_PATH_MASTERPASSWD"/etc/master.passwd", O_RDONLY0x0000 | O_CLOEXEC0x10000); |
| 154 | if (pfd == -1) |
| 155 | pw_error(_PATH_MASTERPASSWD"/etc/master.passwd", 1, 1); |
| 156 | |
| 157 | /* Update master.passwd file and rebuild spwd.db. */ |
| 158 | pw_copy(pfd, tfd, pw, opw); |
| 159 | free(opw); |
| 160 | if (pw_mkdb(uname, pwflags) == -1) |
| 161 | pw_error(NULL((void *)0), 0, 1); |
| 162 | |
| 163 | fprintf(stderr(&__sF[2]), "passwd: password updated successfully\n"); |
| 164 | |
| 165 | return(0); |
| 166 | } |
| 167 | |
| 168 | char * |
| 169 | getnewpasswd(struct passwd *pw, login_cap_t *lc, int authenticated) |
| 170 | { |
| 171 | static char hash[_PASSWORD_LEN128]; |
| 172 | char newpass[1024]; |
| 173 | char *p, *pref; |
| 174 | int tries, pwd_tries; |
| 175 | sig_t saveint, savequit; |
| 176 | |
| 177 | saveint = signal(SIGINT2, kbintr); |
| 178 | savequit = signal(SIGQUIT3, kbintr); |
| 179 | |
| 180 | if (!authenticated) { |
| 181 | fprintf(stderr(&__sF[2]), "Changing password for %s.\n", pw->pw_name); |
| 182 | if (uid != 0 && pw->pw_passwd[0] != '\0') { |
| 183 | char oldpass[1024]; |
| 184 | |
| 185 | p = readpassphrase("Old password:", oldpass, |
| 186 | sizeof(oldpass), RPP_ECHO_OFF0x00); |
| 187 | if (p == NULL((void *)0) || *p == '\0') { |
| 188 | fprintf(stderr(&__sF[2]), "%s\n", UNCHANGED_MSG"Password unchanged."); |
| 189 | pw_abort(); |
| 190 | exit(p == NULL((void *)0) ? 1 : 0); |
| 191 | } |
| 192 | if (crypt_checkpass(p, pw->pw_passwd) != 0) { |
| 193 | errno(*__errno()) = EACCES13; |
| 194 | explicit_bzero(oldpass, sizeof(oldpass)); |
| 195 | pw_error(NULL((void *)0), 1, 1); |
| 196 | } |
| 197 | explicit_bzero(oldpass, sizeof(oldpass)); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | pwd_tries = pwd_gettries(lc); |
| 202 | |
| 203 | for (newpass[0] = '\0', tries = 0;;) { |
| 204 | char repeat[1024]; |
| 205 | |
| 206 | p = readpassphrase("New password:", newpass, sizeof(newpass), |
| 207 | RPP_ECHO_OFF0x00); |
| 208 | if (p == NULL((void *)0) || *p == '\0') { |
| 209 | fprintf(stderr(&__sF[2]), "%s\n", UNCHANGED_MSG"Password unchanged."); |
| 210 | pw_abort(); |
| 211 | exit(p == NULL((void *)0) ? 1 : 0); |
| 212 | } |
| 213 | if (strcmp(p, "s/key") == 0) { |
| 214 | fprintf(stderr(&__sF[2]), "That password collides with a system feature. Choose another.\n"); |
| 215 | continue; |
| 216 | } |
| 217 | |
| 218 | if ((tries++ < pwd_tries || pwd_tries == 0) && |
| 219 | pwd_check(lc, p) == 0) |
| 220 | continue; |
| 221 | p = readpassphrase("Retype new password:", repeat, sizeof(repeat), |
| 222 | RPP_ECHO_OFF0x00); |
| 223 | if (p != NULL((void *)0) && strcmp(newpass, p) == 0) { |
| 224 | explicit_bzero(repeat, sizeof(repeat)); |
| 225 | break; |
| 226 | } |
| 227 | fprintf(stderr(&__sF[2]), "Mismatch; try again, EOF to quit.\n"); |
| 228 | explicit_bzero(repeat, sizeof(repeat)); |
| 229 | explicit_bzero(newpass, sizeof(newpass)); |
| 230 | } |
| 231 | |
| 232 | (void)signal(SIGINT2, saveint); |
| 233 | (void)signal(SIGQUIT3, savequit); |
| 234 | |
| 235 | pref = login_getcapstr(lc, "localcipher", NULL((void *)0), NULL((void *)0)); |
| 236 | if (crypt_newhash(newpass, pref, hash, sizeof(hash)) != 0) { |
| 237 | fprintf(stderr(&__sF[2]), "Couldn't generate hash.\n"); |
| 238 | explicit_bzero(newpass, sizeof(newpass)); |
| 239 | pw_error(NULL((void *)0), 0, 0); |
| 240 | } |
| 241 | explicit_bzero(newpass, sizeof(newpass)); |
| 242 | free(pref); |
| 243 | return hash; |
| 244 | } |
| 245 | |
| 246 | void |
| 247 | kbintr(int signo) |
| 248 | { |
| 249 | dprintf(STDOUT_FILENO1, "\n%s\n", UNCHANGED_MSG"Password unchanged."); |
| 250 | _exit(0); |
| 251 | } |