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-rw-r--r--login-utils/passwd.c466
1 files changed, 313 insertions, 153 deletions
diff --git a/login-utils/passwd.c b/login-utils/passwd.c
index 1c786e94e..f707c0521 100644
--- a/login-utils/passwd.c
+++ b/login-utils/passwd.c
@@ -1,12 +1,43 @@
-/* passwd.c - change password on an account
+/*
+ * passwd.c - change password on an account
+ *
* Initially written for Linux by Peter Orbaek <poe@daimi.aau.dk>
* Currently maintained at ftp://ftp.daimi.aau.dk/pub/linux/poe/
+
+ Hacked by Alvaro Martinez Echevarria, alvaro@enano.etsit.upm.es,
+ to allow peaceful coexistence with yp. Nov 94.
+
+ Hacked to allow root to set passwd from command line.
+ by Arpad Magossanyi (mag@tas.vein.hu)
+
+ Hacked by Peter Breitenlohner, peb@mppmu.mpg.de,
+ moved Alvaro's changes to setpwnam.c (so they get used
+ by chsh and chfn as well). Oct 5, 96.
+
*/
-/* Hacked by Alvaro Martinez Echevarria, alvaro@enano.etsit.upm.es,
- to allow peaceful coexistence with yp. Nov 94. */
-/* Hacked to allow root to set passwd from command line.
- by Arpad Magossanyi (mag@tas.vein.hu) */
+/*
+ * Sun Oct 15 13:18:34 1995 Martin Schulze <joey@finlandia.infodrom.north.de>
+ *
+ * I have completely rewritten the whole argument handlig (what?)
+ * to support two things. First I wanted "passwd $user $pw" to
+ * work and second I wanted simplicity checks to be done for
+ * root, too. Only root can turn this of using the -f
+ * switch. Okay, I started with this to support -V version
+ * information, but one thing comes to the next. *sigh*
+ * In a later step perhaps we'll be able to support shadow
+ * passwords. (?)
+ *
+ * I have also included a DEBUG mode (-DDEBUG) to test the
+ * argument handling _without_ any write attempt to
+ * /etc/passwd.
+ *
+ * If you're paranoid about security on your system, you may want
+ * to add -DLOGALL to CFLAGS. This will turn on additional syslog
+ * logging of every password change. (user changes are logged as
+ * auth.notice, but changing root's password is logged as
+ * auth.warning. (Of course, the password itself is not logged.)
+ */
/*
* Usage: passwd [username [password]]
@@ -17,7 +48,10 @@
#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
+#include <stdarg.h>
#include <termios.h>
+#include <getopt.h>
+#include <malloc.h>
#include <fcntl.h>
#include <pwd.h>
#include <ctype.h>
@@ -26,21 +60,170 @@
#include <errno.h>
#include <sys/resource.h>
-extern int is_local(char *);
+#if defined (__GNU_LIBRARY__) && __GNU_LIBRARY__ > 1
+#include <crypt.h>
+#endif
+
+#if 0
+# include "../version.h"
+#else
+char version[] = "admutil 1.18, 15-Oct-95";
+#endif
+
+#ifndef _PATH_CHFN
+# define _PATH_CHFN "/usr/bin/chfn"
+# define _PATH_CHSH "/usr/bin/chsh"
+#endif
+
+#define LOGALL
+
+#ifdef LOGALL
+#include <syslog.h>
+#endif /* LOGALL */
+
+extern int is_local(char *); /* islocal.c */
+extern int setpwnam(struct passwd *); /* setpwnam.c */
#define ascii_to_bin(c) ((c)>='a'?(c-59):(c)>='A'?((c)-53):(c)-'.')
#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
-#define MAX_LENGTH 1024
-
static void
-pexit(str)
- char *str;
+pexit(char *str, ...)
{
- perror(str);
+ va_list vlst;
+
+ va_start(vlst, str);
+ vfprintf(stderr, str, vlst);
+ fprintf(stderr, ": ");
+ perror("");
+ va_end(vlst);
exit(1);
}
+/*
+ * Do various checks for stupid passwords here...
+ *
+ * This would probably be the best place for checking against
+ * dictionaries. :-)
+ */
+
+int check_passwd_string(char *passwd, char *string)
+{
+ int r;
+ char *p, *q;
+
+ r = 0;
+ /* test for string at the beginning of passwd */
+ for (p = passwd, q = string; *q && *p; q++, p++) {
+ if(tolower(*p) != tolower(*q)) {
+ r++;
+ break;
+ }
+ }
+
+ /* test for reverse string at the beginning of passwd */
+ for (p = passwd, q = string + strlen(string)-1;
+ *p && q >= string; p++, q--) {
+ if(tolower(*p) != tolower(*q)) {
+ r++;
+ break;
+ }
+ }
+
+ /* test for string at the end of passwd */
+ for (p = passwd + strlen(passwd)-1, q = string + strlen(string)-1;
+ q >= string && p >= passwd; q--, p--) {
+ if(tolower(*p) != tolower(*q)) {
+ r++;
+ break;
+ }
+ }
+
+ /* test for reverse string at the beginning of passwd */
+ for (p = passwd + strlen(passwd)-1, q = string;
+ p >= passwd && *q; p--, q++) {
+ if(tolower(*p) != tolower(*q)) {
+ r++;
+ break;
+ }
+ }
+
+ if (r != 4) {
+ return 0;
+ }
+ return 1;
+}
+
+int check_passwd(char *passwd, char *oldpasswd, char *user, char *gecos)
+{
+ int ucase, lcase, digit, other;
+ char *c, *g, *p;
+
+ if ( (strlen(passwd) < 6) ) {
+ printf("The password must have at least 6 characters, try again.\n");
+ return 0;
+ }
+
+ other = digit = ucase = lcase = 0;
+ for (p = passwd; *p; p++) {
+ ucase = ucase || isupper(*p);
+ lcase = lcase || islower(*p);
+ digit = digit || isdigit(*p);
+ other = other || !isalnum(*p);
+ }
+
+ if ( (other + digit + ucase + lcase) < 2) {
+ printf("The password must contain characters out of two of the following\n");
+ printf("classes: upper and lower case letters, digits and non alphanumeric\n");
+ printf("characters. See passwd(1) for more information.\n");
+ return 0;
+ }
+
+ if ( oldpasswd[0] && !strncmp(oldpasswd, crypt(passwd, oldpasswd), 13) ) {
+ printf("You cannot reuse the old password.\n");
+ return 0;
+ }
+
+ if ( !check_passwd_string(passwd, user) ) {
+ printf("Please don't use something like your username as password!\n");
+ return 0;
+ }
+
+ /* check against realname */
+ if ( (c = index(gecos, ',')) ) {
+ if ( c-gecos && (g = (char *)malloc (c-gecos+1)) ) {
+ strncpy (g, gecos, c-gecos);
+ g[c-gecos] = 0;
+ while ( (c=rindex(g, ' ')) ) {
+ if ( !check_passwd_string(passwd, c+1) ) {
+ printf("Please don't use something like your realname as password!\n");
+ free (g);
+ return 0;
+ }
+ *c = '\0';
+ } /* while */
+ if ( !check_passwd_string(passwd, g) ) {
+ printf("Please don't use something like your realname as password!\n");
+ free (g);
+ return 0;
+ }
+ free (g);
+ } /* if malloc */
+ }
+
+ /*
+ * if ( !check_password_dict(passwd) ) ...
+ */
+
+ return 1; /* fine */
+}
+
+void usage()
+{
+ printf ("Usage: passwd [username [password]]\n");
+ printf("Only root may use the one and two argument forms.\n");
+}
+
int
main(argc, argv)
int argc;
@@ -50,56 +233,101 @@ main(argc, argv)
uid_t gotuid = getuid();
char *pwdstr = NULL, *cryptstr, *oldstr;
char pwdstr1[10];
- int ucase, lcase, other;
- char *p, *q, *user;
+ char *user;
time_t tm;
char salt[2];
- FILE *fd_in, *fd_out;
- char line[MAX_LENGTH];
- char colonuser[16];
- int error=0;
- int r;
- int ptmp;
-#ifndef USE_SETPWNAM
- struct rlimit rlim;
-#endif
+ int force_passwd = 0;
+ int silent = 0;
+ char c;
+ int opt_index;
+ int fullname = 0, shell = 0;
+ static const struct option long_options[] =
+ {
+ {"fullname", no_argument, 0, 'f'},
+ {"shell", no_argument, 0, 's'},
+ {"force", no_argument, 0, 'o'},
+ {"quiet", no_argument, 0, 'q'},
+ {"silent", no_argument, 0, 'q'},
+ {"version", no_argument, 0, 'v'},
+ {0, 0, 0, 0}
+ };
- if(argc > 3) {
- puts("Too many arguments");
- exit(1);
- } else if(argc >= 2) {
- if(gotuid) {
- puts("Only root can change the password for others");
+ optind = 0;
+ while ( (c = getopt_long(argc, argv, "foqsvV", long_options, &opt_index)) != -1 ) {
+ switch (c) {
+ case 'f':
+ fullname = 1;
+ break;
+ case 's':
+ shell = 1;
+ break;
+ case 'o':
+ force_passwd = 1;
+ break;
+ case 'q':
+ silent = 1;
+ break;
+ case 'V':
+ case 'v':
+ printf("%s\n", version);
+ exit(0);
+ default:
+ fprintf(stderr, "Usage: passwd [-foqsvV] [user [password]]\n");
exit(1);
- }
- user = argv[1];
-
- if (argc == 3) pwdstr = argv[2];
-
- } else {
- if (!(user = getlogin())) {
- if (!(pe = getpwuid( getuid() ))) {
+ } /* switch (c) */
+ } /* while */
+
+ if (fullname || shell) {
+ char *args[100];
+ int i, j;
+
+ setuid(getuid()); /* drop special privs. */
+ if (fullname)
+ args[0] = _PATH_CHFN;
+ else
+ args[0] = _PATH_CHSH;
+
+ for (i = optind, j = 1; (i < argc) && (j < 99); i++, j++)
+ args[j] = argv[i];
+
+ args[j] = NULL;
+ execv(args[0], args);
+ fprintf(stderr, "Can't exec %s: %s\n", args[0], strerror(errno));
+ exit(1);
+ }
+
+ switch (argc - optind) {
+ case 0:
+ if ( !(user = getlogin()) ) {
+ if ( !(pe = getpwuid( getuid() )) ) {
pexit("Cannot find login name");
} else
- user = pe->pw_name;
+ user = pe->pw_name;
}
- }
+ break;
+ case 1:
+ if(gotuid) {
+ printf("Only root can change the password for others.\n");
+ exit (1);
+ } else
+ user = argv[optind];
+ break;
+ case 2:
+ if(gotuid) {
+ printf("Only root can change the password for others.\n");
+ exit(1);
+ } else {
+ user = argv[optind];
+ pwdstr = argv[optind+1];
+ }
+ break;
+ default:
+ printf("Too many arguments.\n");
+ exit (1);
+ } /* switch */
-#ifndef USE_SETPWNAM
- umask(022);
-
- rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
- setrlimit(RLIMIT_CPU, &rlim);
- setrlimit(RLIMIT_FSIZE, &rlim);
- setrlimit(RLIMIT_STACK, &rlim);
- setrlimit(RLIMIT_DATA, &rlim);
- setrlimit(RLIMIT_RSS, &rlim);
- rlim.rlim_cur = rlim.rlim_max = 0;
- setrlimit(RLIMIT_CORE, &rlim);
-#endif
-
if(!(pe = getpwnam(user))) {
- pexit("Can't find username anywhere. Are you really a user?");
+ pexit("Can't find username anywhere. Is `%s' really a user?", user);
}
if (!(is_local(user))) {
@@ -113,9 +341,11 @@ main(argc, argv)
exit(1);
}
- printf( "Changing password for %s\n", user );
+ if ( !silent )
+ printf( "Changing password for %s\n", user );
- if(gotuid && pe->pw_passwd && pe->pw_passwd[0]) {
+ if ( (gotuid && pe->pw_passwd && pe->pw_passwd[0])
+ || (!gotuid && !strcmp(user,"root")) ) {
oldstr = getpass("Enter old password: ");
if(strncmp(pe->pw_passwd, crypt(oldstr, pe->pw_passwd), 13)) {
puts("Illegal password, imposter.");
@@ -123,7 +353,10 @@ main(argc, argv)
}
}
- if (!pwdstr) {
+ if ( pwdstr ) { /* already set on command line */
+ if ( !force_passwd && !check_passwd(pwdstr, pe->pw_passwd, user, pe->pw_gecos) )
+ exit (1);
+ } else {
/* password not set on command line by root, ask for it ... */
redo_it:
@@ -132,126 +365,53 @@ main(argc, argv)
puts("Password not changed.");
exit(1);
}
-
- if((strlen(pwdstr) < 6) && gotuid) {
- puts("The password must have at least 6 characters, try again.");
- goto redo_it;
- }
-
- other = ucase = lcase = 0;
- for(p = pwdstr; *p; p++) {
- ucase = ucase || isupper(*p);
- lcase = lcase || islower(*p);
- other = other || !isalpha(*p);
- }
-
- if((!ucase || !lcase) && !other && gotuid) {
- puts("The password must have both upper- and lowercase");
- puts("letters, or non-letters; try again.");
- goto redo_it;
- }
-
- if (pe->pw_passwd[0]
- && !strncmp(pe->pw_passwd, crypt(pwdstr, pe->pw_passwd), 13)
- && gotuid) {
- puts("You cannot reuse the old password.");
- goto redo_it;
- }
-
- r = 0;
- for(p = pwdstr, q = pe->pw_name; *q && *p; q++, p++) {
- if(tolower(*p) != tolower(*q)) {
- r = 1;
- break;
- }
- }
-
- for(p = pwdstr + strlen(pwdstr)-1, q = pe->pw_name;
- *q && p >= pwdstr; q++, p--) {
- if(tolower(*p) != tolower(*q)) {
- r += 2;
- break;
- }
- }
-
- if(gotuid && r != 3) {
- puts("Please don't use something like your username as password!");
+
+ if ( (gotuid || (!gotuid && !force_passwd))
+ && !check_passwd(pwdstr, pe->pw_passwd, user, pe->pw_gecos) )
goto redo_it;
- }
-
- /* do various other checks for stupid passwords here... */
strncpy(pwdstr1, pwdstr, 9);
+ pwdstr1[9] = 0;
pwdstr = getpass("Re-type new password: ");
if(strncmp(pwdstr, pwdstr1, 8)) {
puts("You misspelled it. Password not changed.");
exit(1);
}
- } /* pwdstr != argv[2] i.e. password set on command line */
+ } /* pwdstr i.e. password set on command line */
- time(&tm);
+ time(&tm); tm ^= getpid();
salt[0] = bin_to_ascii(tm & 0x3f);
salt[1] = bin_to_ascii((tm >> 6) & 0x3f);
cryptstr = crypt(pwdstr, salt);
if (pwdstr[0] == 0) cryptstr = "";
-#ifdef USE_SETPWNAM
+#ifdef LOGALL
+ openlog("passwd", 0, LOG_AUTH);
+ if (gotuid)
+ syslog(LOG_NOTICE,"password changed, user %s",user);
+ else {
+ if ( !strcmp(user, "root") )
+ syslog(LOG_WARNING,"ROOT PASSWORD CHANGED");
+ else
+ syslog(LOG_NOTICE,"password changed by root, user %s",user);
+ }
+ closelog();
+#endif /* LOGALL */
+
pe->pw_passwd = cryptstr;
+#ifdef DEBUG
+ printf ("calling setpwnam to set password.\n");
+#else
if (setpwnam( pe ) < 0) {
perror( "setpwnam" );
printf( "Password *NOT* changed. Try again later.\n" );
exit( 1 );
}
-#else
- if ((ptmp = open("/etc/ptmp", O_CREAT|O_EXCL|O_WRONLY, 0600)) < 0) {
- pexit("Can't exclusively open /etc/ptmp, can't update password");
- }
- fd_out = fdopen(ptmp, "w");
-
- if(!(fd_in = fopen("/etc/passwd", "r"))) {
- pexit("Can't read /etc/passwd, can't update password");
- }
-
- strcpy(colonuser, user);
- strcat(colonuser, ":");
- while(fgets(line, sizeof(line), fd_in)) {
- if(!strncmp(line,colonuser,strlen(colonuser))) {
- pe->pw_passwd = cryptstr;
- if(putpwent(pe, fd_out) < 0) {
- error = 1;
- }
- } else {
- if(fputs(line,fd_out) < 0) {
- error = 1;
- }
- }
- if(error) {
- puts("Error while writing new password file, password not changed.");
- fclose(fd_out);
- endpwent();
- unlink("/etc/ptmp");
- exit(1);
- }
- }
- fclose(fd_in);
- fclose(fd_out);
-
- unlink("/etc/passwd.OLD"); /* passwd.OLD not required */
- if (link("/etc/passwd", "/etc/passwd.OLD"))
- pexit("link(/etc/passwd, /etc/passwd.OLD) failed: no change");
- if (unlink("/etc/passwd") < 0)
- pexit("unlink(/etc/passwd) failed: no change");
- if (link("/etc/ptmp", "/etc/passwd") < 0)
- pexit("link(/etc/ptmp, /etc/passwd) failed: PASSWD file DROPPED!!");
- if (unlink("/etc/ptmp") < 0)
- pexit("unlink(/etc/ptmp) failed: /etc/ptmp still exists");
-
- chmod("/etc/passwd", 0644);
- chown("/etc/passwd", 0, 0);
#endif
-
- puts("Password changed.");
+
+ if ( !silent )
+ printf("Password changed.\n");
exit(0);
}
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