X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Fpasswd.c;h=b7b7423fd6ac0278be0be90d0f3ac961c0b44a54;hb=517a82c5b6b5e279f3e96a6774445a2952ca312b;hp=5d8380d4cbd92ccede3b93aeead21cb0515b5b02;hpb=d5bd137a247145afabfbc3a3c376ad8787381d8f;p=oweals%2Fbusybox.git

diff --git a/loginutils/passwd.c b/loginutils/passwd.c
index 5d8380d4c..b7b7423fd 100644
--- a/loginutils/passwd.c
+++ b/loginutils/passwd.c
@@ -1,400 +1,245 @@
 /* vi: set sw=4 ts=4: */
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <signal.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <utime.h>
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//config:config PASSWD
+//config:	bool "passwd"
+//config:	default y
+//config:	select FEATURE_SYSLOG
+//config:	help
+//config:	  passwd changes passwords for user and group accounts. A normal user
+//config:	  may only change the password for his/her own account, the super user
+//config:	  may change the password for any account. The administrator of a group
+//config:	  may change the password for the group.
+//config:
+//config:	  Note that Busybox binary must be setuid root for this applet to
+//config:	  work properly.
+//config:
+//config:config FEATURE_PASSWD_WEAK_CHECK
+//config:	bool "Check new passwords for weakness"
+//config:	default y
+//config:	depends on PASSWD
+//config:	help
+//config:	  With this option passwd will refuse new passwords which are "weak".
+
+//applet:/* Needs to be run by root or be suid root - needs to change /etc/{passwd,shadow}: */
+//applet:IF_PASSWD(APPLET(passwd, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
+
+//kbuild:lib-$(CONFIG_PASSWD) += passwd.o
+
+//usage:#define passwd_trivial_usage
+//usage:       "[OPTIONS] [USER]"
+//usage:#define passwd_full_usage "\n\n"
+//usage:       "Change USER's password (default: current user)"
+//usage:     "\n"
+//usage:     "\n	-a ALG	"CRYPT_METHODS_HELP_STR
+//usage:     "\n	-d	Set password to ''"
+//usage:     "\n	-l	Lock (disable) account"
+//usage:     "\n	-u	Unlock (enable) account"
+
+#include "libbb.h"
 #include <syslog.h>
-#include <time.h>
-#include <sys/resource.h>
-#include <errno.h>
+#include <sys/resource.h> /* setrlimit */
 
-#include "busybox.h"
+static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
+{
+	char salt[MAX_PW_SALT_LEN];
+	char *orig = (char*)"";
+	char *newp = NULL;
+	char *cp = NULL;
+	char *ret = NULL; /* failure so far */
+
+	if (myuid != 0 && pw->pw_passwd[0]) {
+		char *encrypted;
+
+		orig = bb_ask_stdin("Old password: "); /* returns ptr to static */
+		if (!orig)
+			goto err_ret;
+		encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
+		if (strcmp(encrypted, pw->pw_passwd) != 0) {
+			syslog(LOG_WARNING, "incorrect password for %s", pw->pw_name);
+			bb_do_delay(LOGIN_FAIL_DELAY);
+			puts("Incorrect password");
+			goto err_ret;
+		}
+		if (ENABLE_FEATURE_CLEAN_UP)
+			free(encrypted);
+	}
+	orig = xstrdup(orig); /* or else bb_ask_stdin() will destroy it */
+	newp = bb_ask_stdin("New password: "); /* returns ptr to static */
+	if (!newp)
+		goto err_ret;
+	newp = xstrdup(newp); /* we are going to bb_ask_stdin() again, so save it */
+	if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
+	 && obscure(orig, newp, pw)
+	 && myuid != 0
+	) {
+		goto err_ret; /* non-root is not allowed to have weak passwd */
+	}
 
-static char crypt_passwd[128];
+	cp = bb_ask_stdin("Retype password: ");
+	if (!cp)
+		goto err_ret;
+	if (strcmp(cp, newp) != 0) {
+		puts("Passwords don't match");
+		goto err_ret;
+	}
 
-static int create_backup(const char *backup, FILE * fp);
-static int new_password(const struct passwd *pw, int amroot, int algo);
-static void set_filesize_limit(int blocks);
+	crypt_make_pw_salt(salt, algo);
 
+	/* pw_encrypt returns malloced str */
+	ret = pw_encrypt(newp, salt, 1);
+	/* whee, success! */
 
-static int get_algo(char *a)
-{
-	int x = 1;					/* standard: MD5 */
+ err_ret:
+	nuke_str(orig);
+	if (ENABLE_FEATURE_CLEAN_UP) free(orig);
 
-	if (strcasecmp(a, "des") == 0)
-		x = 0;
-	return x;
-}
+	nuke_str(newp);
+	if (ENABLE_FEATURE_CLEAN_UP) free(newp);
 
+	nuke_str(cp);
+	return ret;
+}
 
-static int update_passwd(const struct passwd *pw, char *crypt_pw)
+int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int passwd_main(int argc UNUSED_PARAM, char **argv)
 {
-	char filename[1024];
-	char buf[1025];
-	char buffer[80];
-	char username[32];
-	char *pw_rest;
-	int mask;
-	int continued;
-	FILE *fp;
-	FILE *out_fp;
-	struct stat sb;
-	struct flock lock;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-	if (access(bb_path_shadow_file, F_OK) == 0) {
-		snprintf(filename, sizeof filename, "%s", bb_path_shadow_file);
-	} else
+	enum {
+		OPT_algo   = (1 << 0), /* -a - password algorithm */
+		OPT_lock   = (1 << 1), /* -l - lock account */
+		OPT_unlock = (1 << 2), /* -u - unlock account */
+		OPT_delete = (1 << 3), /* -d - delete password */
+		OPT_lud    = OPT_lock | OPT_unlock | OPT_delete,
+	};
+	unsigned opt;
+	int rc;
+	const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
+	const char *filename;
+	char *myname;
+	char *name;
+	char *newp;
+	struct passwd *pw;
+	uid_t myuid;
+	struct rlimit rlimit_fsize;
+	char c;
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	/* Using _r function to avoid pulling in static buffers */
+	struct spwd spw;
+	char buffer[256];
 #endif
-	{
-		snprintf(filename, sizeof filename, "%s", bb_path_passwd_file);
-	}
 
-	if (((fp = fopen(filename, "r+")) == 0) || (fstat(fileno(fp), &sb))) {
-		/* return 0; */
-		return 1;
-	}
+	logmode = LOGMODE_BOTH;
+	openlog(applet_name, 0, LOG_AUTH);
+	opt = getopt32(argv, "a:lud", &opt_a);
+	//argc -= optind;
+	argv += optind;
 
-	/* Lock the password file before updating */
-	lock.l_type = F_WRLCK;
-	lock.l_whence = SEEK_SET;
-	lock.l_start = 0;
-	lock.l_len = 0;
-	if (fcntl(fileno(fp), F_SETLK, &lock) < 0) {
-		fprintf(stderr, "%s: %s\n", filename, strerror(errno));
-		return 1;
-	}
-	lock.l_type = F_UNLCK;
+	myuid = getuid();
+	/* -l, -u, -d require root priv and username argument */
+	if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
+		bb_show_usage();
 
-	snprintf(buf, sizeof buf, "%s-", filename);
-	if (create_backup(buf, fp)) {
-		fcntl(fileno(fp), F_SETLK, &lock);
-		fclose(fp);
-		return 1;
-	}
-	snprintf(buf, sizeof buf, "%s+", filename);
-	mask = umask(0777);
-	out_fp = fopen(buf, "w");
-	umask(mask);
-	if ((!out_fp) || (fchmod(fileno(out_fp), sb.st_mode & 0777))
-		|| (fchown(fileno(out_fp), sb.st_uid, sb.st_gid))) {
-		fcntl(fileno(fp), F_SETLK, &lock);
-		fclose(fp);
-		fclose(out_fp);
-		return 1;
+	/* Will complain and die if username not found */
+	myname = xstrdup(xuid2uname(myuid));
+	name = argv[0] ? argv[0] : myname;
+
+	pw = xgetpwnam(name);
+	if (myuid != 0 && pw->pw_uid != myuid) {
+		/* LOGMODE_BOTH */
+		bb_error_msg_and_die("%s can't change password for %s", myname, name);
 	}
 
-	continued = 0;
-	snprintf(username, sizeof username, "%s:", pw->pw_name);
-	rewind(fp);
-	while (!feof(fp)) {
-		fgets(buffer, sizeof buffer, fp);
-		if (!continued) {		// Check to see if we're updating this line.
-			if (strncmp(username, buffer, strlen(username)) == 0) {	// we have a match.
-				pw_rest = strchr(buffer, ':');
-				*pw_rest++ = '\0';
-				pw_rest = strchr(pw_rest, ':');
-				fprintf(out_fp, "%s:%s%s", buffer, crypt_pw, pw_rest);
-			} else {
-				fputs(buffer, out_fp);
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	{
+		/* getspnam_r may return 0 yet set result to NULL.
+		 * At least glibc 2.4 does this. Be extra paranoid here. */
+		struct spwd *result = NULL;
+		errno = 0;
+		if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
+		 || !result /* no error, but no record found either */
+		 || strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
+		) {
+			if (errno != ENOENT) {
+				/* LOGMODE_BOTH */
+				bb_perror_msg("no record of %s in %s, using %s",
+					name, bb_path_shadow_file,
+					bb_path_passwd_file);
 			}
+			/* else: /etc/shadow does not exist,
+			 * apparently we are on a shadow-less system,
+			 * no surprise there */
 		} else {
-			fputs(buffer, out_fp);
-		}
-		if (buffer[strlen(buffer) - 1] == '\n') {
-			continued = 0;
-		} else {
-			continued = 1;
+			pw->pw_passwd = result->sp_pwdp;
 		}
-		bzero(buffer, sizeof buffer);
 	}
+#endif
 
-	if (fflush(out_fp) || fsync(fileno(out_fp)) || fclose(out_fp)) {
-		unlink(buf);
-		fcntl(fileno(fp), F_SETLK, &lock);
-		fclose(fp);
-		return 1;
-	}
-	if (rename(buf, filename) < 0) {
-		fcntl(fileno(fp), F_SETLK, &lock);
-		fclose(fp);
-		return 1;
-	} else {
-		fcntl(fileno(fp), F_SETLK, &lock);
-		fclose(fp);
-		return 0;
-	}
-}
-
-
-extern int passwd_main(int argc, char **argv)
-{
-	int amroot;
-	char *cp;
-	char *np;
-	char *name;
-	char *myname;
-	int flag;
-	int algo = 1;				/* -a - password algorithm */
-	int lflg = 0;				/* -l - lock account */
-	int uflg = 0;				/* -u - unlock account */
-	int dflg = 0;				/* -d - delete password */
-	const struct passwd *pw;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-	const struct spwd *sp;
-#endif							/* CONFIG_FEATURE_SHADOWPASSWDS */
-	amroot = (getuid() == 0);
-	openlog("passwd", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
-	while ((flag = getopt(argc, argv, "a:dlu")) != EOF) {
-		switch (flag) {
-		case 'a':
-			algo = get_algo(optarg);
-			break;
-		case 'd':
-			dflg++;
-			break;
-		case 'l':
-			lflg++;
-			break;
-		case 'u':
-			uflg++;
-			break;
-		default:
-			bb_show_usage();
-		}
-	}
-	myname = (char *) bb_xstrdup(bb_getpwuid(NULL, getuid(), -1));
-	/* exits on error */
-	if (optind < argc) {
-		name = argv[optind];
-	} else {
-		name = myname;
-	}
-	if ((lflg || uflg || dflg) && (optind >= argc || !amroot)) {
-		bb_show_usage();
-	}
-	pw = getpwnam(name);
-	if (!pw) {
-		bb_error_msg_and_die("Unknown user %s\n", name);
-	}
-	if (!amroot && pw->pw_uid != getuid()) {
-		syslog(LOG_WARNING, "can't change pwd for `%s'", name);
-		bb_error_msg_and_die("Permission denied.\n");
-	}
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-	sp = getspnam(name);
-	if (!sp) {
-		sp = (struct spwd *) pwd_to_spwd(pw);
-	}
-	cp = sp->sp_pwdp;
-	np = sp->sp_namp;
-#else
-	cp = pw->pw_passwd;
-	np = name;
-#endif							/* CONFIG_FEATURE_SHADOWPASSWDS */
-
-	safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
-	if (!(dflg || lflg || uflg)) {
-		if (!amroot) {
-			if (cp[0] == '!') {
-				syslog(LOG_WARNING, "password locked for `%s'", np);
-				bb_error_msg_and_die( "The password for `%s' cannot be changed.\n", np);
-			}
+	/* Decide what the new password will be */
+	newp = NULL;
+	c = pw->pw_passwd[0] - '!';
+	if (!(opt & OPT_lud)) {
+		if (myuid != 0 && !c) { /* passwd starts with '!' */
+			/* LOGMODE_BOTH */
+			bb_error_msg_and_die("can't change "
+					"locked password for %s", name);
 		}
 		printf("Changing password for %s\n", name);
-		if (new_password(pw, amroot, algo)) {
-			bb_error_msg_and_die( "The password for %s is unchanged.\n", name);
-		}
-	} else if (lflg) {
-		if (crypt_passwd[0] != '!') {
-			memmove(&crypt_passwd[1], crypt_passwd,
-					sizeof crypt_passwd - 1);
-			crypt_passwd[sizeof crypt_passwd - 1] = '\0';
-			crypt_passwd[0] = '!';
-		}
-	} else if (uflg) {
-		if (crypt_passwd[0] == '!') {
-			memmove(crypt_passwd, &crypt_passwd[1],
-					sizeof crypt_passwd - 1);
+		newp = new_password(pw, myuid, opt_a);
+		if (!newp) {
+			logmode = LOGMODE_STDIO;
+			bb_error_msg_and_die("password for %s is unchanged", name);
 		}
-	} else if (dflg) {
-		crypt_passwd[0] = '\0';
-	}
-	set_filesize_limit(30000);
-	signal(SIGHUP, SIG_IGN);
-	signal(SIGINT, SIG_IGN);
-	signal(SIGQUIT, SIG_IGN);
+	} else if (opt & OPT_lock) {
+		if (!c)
+			goto skip; /* passwd starts with '!' */
+		newp = xasprintf("!%s", pw->pw_passwd);
+	} else if (opt & OPT_unlock) {
+		if (c)
+			goto skip; /* not '!' */
+		/* pw->pw_passwd points to static storage,
+		 * strdup'ing to avoid nasty surprizes */
+		newp = xstrdup(&pw->pw_passwd[1]);
+	} else if (opt & OPT_delete) {
+		newp = (char*)"";
+	}
+
+	rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
+	setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
+	bb_signals(0
+		+ (1 << SIGHUP)
+		+ (1 << SIGINT)
+		+ (1 << SIGQUIT)
+		, SIG_IGN);
 	umask(077);
-	if (setuid(0)) {
-		syslog(LOG_ERR, "can't setuid(0)");
-		bb_error_msg_and_die( "Cannot change ID to root.\n");
-	}
-	if (!update_passwd(pw, crypt_passwd)) {
-		syslog(LOG_INFO, "password for `%s' changed by user `%s'", name,
-			   myname);
-		printf("Password changed.\n");
-	} else {
-		syslog(LOG_WARNING, "an error occurred updating the password file");
-		bb_error_msg_and_die("An error occurred updating the password file.\n");
-	}
-	return (0);
-}
-
-
-
-static int create_backup(const char *backup, FILE * fp)
-{
-	struct stat sb;
-	struct utimbuf ub;
-	FILE *bkfp;
-	int c, mask;
-
-	if (fstat(fileno(fp), &sb))
-		/* return -1; */
-		return 1;
-
-	mask = umask(077);
-	bkfp = fopen(backup, "w");
-	umask(mask);
-	if (!bkfp)
-		/* return -1; */
-		return 1;
-
-	/* TODO: faster copy, not one-char-at-a-time.  --marekm */
-	rewind(fp);
-	while ((c = getc(fp)) != EOF) {
-		if (putc(c, bkfp) == EOF)
-			break;
-	}
-	if (c != EOF || fflush(bkfp)) {
-		fclose(bkfp);
-		/* return -1; */
-		return 1;
-	}
-	if (fclose(bkfp))
-		/* return -1; */
-		return 1;
-
-	ub.actime = sb.st_atime;
-	ub.modtime = sb.st_mtime;
-	utime(backup, &ub);
-	return 0;
-}
-
-static int i64c(int i)
-{
-	if (i <= 0)
-		return ('.');
-	if (i == 1)
-		return ('/');
-	if (i >= 2 && i < 12)
-		return ('0' - 2 + i);
-	if (i >= 12 && i < 38)
-		return ('A' - 12 + i);
-	if (i >= 38 && i < 63)
-		return ('a' - 38 + i);
-	return ('z');
-}
-
-static char *crypt_make_salt(void)
-{
-	time_t now;
-	static unsigned long x;
-	static char result[3];
-
-	time(&now);
-	x += now + getpid() + clock();
-	result[0] = i64c(((x >> 18) ^ (x >> 6)) & 077);
-	result[1] = i64c(((x >> 12) ^ x) & 077);
-	result[2] = '\0';
-	return result;
-}
-
-
-static int new_password(const struct passwd *pw, int amroot, int algo)
-{
-	char *clear;
-	char *cipher;
-	char *cp;
-	char orig[200];
-	char pass[200];
-	time_t start, now;
-
-	if (!amroot && crypt_passwd[0]) {
-		if (!(clear = bb_askpass(0, "Old password:"))) {
-			/* return -1; */
-			return 1;
-		}
-		cipher = pw_encrypt(clear, crypt_passwd);
-		if (strcmp(cipher, crypt_passwd) != 0) {
-			syslog(LOG_WARNING, "incorrect password for `%s'",
-				   pw->pw_name);
-			time(&start);
-			now = start;
-			while (difftime(now, start) < FAIL_DELAY) {
-				sleep(FAIL_DELAY);
-				time(&now);
-			}
-			fprintf(stderr, "Incorrect password.\n");
-			/* return -1; */
-			return 1;
-		}
-		safe_strncpy(orig, clear, sizeof(orig));
-		bzero(clear, strlen(clear));
-		bzero(cipher, strlen(cipher));
-	} else {
-		orig[0] = '\0';
-	}
-	if (! (cp=bb_askpass(0, "Enter the new password (minimum of 5, maximum of 8 characters)\n"
-					  "Please use a combination of upper and lower case letters and numbers.\n"
-					  "Enter new password: ")))
+	xsetuid(0);
+
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	filename = bb_path_shadow_file;
+	rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
+	if (rc > 0)
+		/* password in /etc/shadow was updated */
+		newp = (char*) "x";
+	if (rc >= 0)
+		/* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
+#endif
 	{
-		bzero(orig, sizeof orig);
-		/* return -1; */
-		return 1;
+		filename = bb_path_passwd_file;
+		rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
 	}
-	safe_strncpy(pass, cp, sizeof(pass));
-	bzero(cp, strlen(cp));
-	/* if (!obscure(orig, pass, pw)) { */
-	if (obscure(orig, pass, pw)) {
-		if (amroot) {
-			printf("\nWarning: weak password (continuing).\n");
-		} else {
-			/* return -1; */
-			return 1;
-		}
-	}
-	if (!(cp = bb_askpass(0, "Re-enter new password: "))) {
-		bzero(orig, sizeof orig);
-		/* return -1; */
-		return 1;
-	}
-	if (strcmp(cp, pass)) {
-		fprintf(stderr, "Passwords do not match.\n");
-		/* return -1; */
-		return 1;
+	/* LOGMODE_BOTH */
+	if (rc < 0)
+		bb_error_msg_and_die("can't update password file %s", filename);
+	bb_error_msg("password for %s changed by %s", name, myname);
+
+	/*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
+ skip:
+	if (!newp) {
+		bb_error_msg_and_die("password for %s is already %slocked",
+			name, (opt & OPT_unlock) ? "un" : "");
 	}
-	bzero(cp, strlen(cp));
-	bzero(orig, sizeof(orig));
 
-	if (algo == 1) {
-		cp = pw_encrypt(pass, "$1$");
-	} else
-		cp = pw_encrypt(pass, crypt_make_salt());
-	bzero(pass, sizeof pass);
-	safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd));
+	if (ENABLE_FEATURE_CLEAN_UP)
+		free(myname);
 	return 0;
 }
-
-static void set_filesize_limit(int blocks)
-{
-	struct rlimit rlimit_fsize;
-
-	rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * blocks;
-	setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
-}