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-rw-r--r--toys/lsb/passwd.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/toys/lsb/passwd.c b/toys/lsb/passwd.c
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+/* vi: set sw=4 ts=4:
+ *
+ * passwd.c - Program to upadte user password.
+ *
+ * Copyright 2012 Ashwini Kumar <ak.ashwini@gmail.com>
+ * Modified 2012 Jason Kyungwan Han <asura321@gmail.com>
+ *
+ * Not in SUSv4.
+
+USE_PASSWD(NEWTOY(passwd, ">1a:dlu", TOYFLAG_STAYROOT|TOYFLAG_USR|TOYFLAG_BIN))
+
+config PASSWD
+ bool "passwd"
+ default y
+ help
+ usage: passwd [-a ALGO] [-d] [-l] [-u] <account name>
+
+ update user’s authentication tokens. Default : current user
+
+ -a ALGO Encryption method (des, md5, sha256, sha512) default: des
+ -d Set password to ''
+ -l Lock (disable) account
+ -u Unlock (enable) account
+
+*/
+
+#include "toys.h"
+#include <time.h>
+
+
+DEFINE_GLOBALS(
+ char *algo;
+)
+
+#define TT this.passwd
+
+#define FLAG_u (1 << 0)
+#define FLAG_l (1 << 1)
+#define FLAG_d (1 << 2)
+#define FLAG_a (1 << 3)
+
+#define MAX_SALT_LEN 20 //3 for id, 16 for key, 1 for '\0'
+#define URANDOM_PATH "/dev/urandom"
+
+#ifndef _GNU_SOURCE
+char *strcasestr(const char *haystack, const char *needle);
+#endif
+
+unsigned int random_number_generator(int fd)
+{
+ unsigned int randnum;
+ xreadall(fd, &randnum, sizeof(randnum));
+ return randnum;
+}
+
+
+
+char inttoc(int i)
+{
+ // salt value uses 64 chracters in "./0-9a-zA-Z"
+ const char character_set[]="./0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+ i &= 0x3f; // masking for using 10 bits only
+ return character_set[i];
+}
+
+int get_salt(char *salt)
+{
+ int i, salt_length = 0;
+ int randfd;
+ if(!strncmp(TT.algo,"des",3)){
+ // 2 bytes salt value is used in des
+ salt_length = 2;
+ } else {
+ *salt++ = '$';
+ if(!strncmp(TT.algo,"md5",3)){
+ *salt++ = '1';
+ // 8 bytes salt value is used in md5
+ salt_length = 8;
+ } else if(!strncmp(TT.algo,"sha256",6)){
+ *salt++ = '5';
+ // 16 bytes salt value is used in sha256
+ salt_length = 16;
+ } else if(!strncmp(TT.algo,"sha512",6)){
+ *salt++ = '6';
+ // 16 bytes salt value is used in sha512
+ salt_length = 16;
+ } else return 1;
+
+ *salt++ = '$';
+ }
+
+ randfd = xopen(URANDOM_PATH, O_RDONLY);
+ for(i=0; i<salt_length; i++)
+ salt[i] = inttoc(random_number_generator(randfd));
+ salt[salt_length+1] = '\0';
+ xclose(randfd);
+
+ return 0;
+}
+
+static int str_check(char *s, char *p)
+{
+ if((strcasestr(s, p) != NULL) || (strcasestr(p, s) != NULL))
+ return 1;
+ return 0;
+}
+
+static void strength_check(char *newp, char *oldp, char *user)
+{
+ char *msg = NULL;
+ if(strlen(newp) < 6) { //Min passwd len
+ msg = "too short";
+ xprintf("BAD PASSWORD: %s\n",msg);
+ }
+ if(!newp[0])
+ return; //passwd is empty
+
+ if(str_check(newp, user)) {
+ msg = "user based password";
+ xprintf("BAD PASSWORD: %s\n",msg);
+ }
+
+ if(oldp[0] && str_check(newp, oldp)) {
+ msg = "based on old passwd";
+ xprintf("BAD PASSWORD: %s\n",msg);
+ }
+}
+
+static int verify_passwd(char * pwd)
+{
+ char * pass;
+
+ if (!pwd) return 1;
+ if (pwd[0] == '!' || pwd[0] == '*') return 1;
+
+ pass = crypt(toybuf, pwd);
+ if (pass != NULL && strcmp(pass, pwd)==0)
+ return 0;
+
+ return 1;
+}
+
+static char *new_password(char *oldp, char *user)
+{
+ char *newp = NULL;
+
+ if(read_password(toybuf, sizeof(toybuf), "New password:"))
+ return NULL; //may be due to Ctrl-C
+
+ newp = xstrdup(toybuf);
+ strength_check(newp, oldp, user);
+ if(read_password(toybuf, sizeof(toybuf), "Retype password:")) {
+ free(newp);
+ return NULL; //may be due to Ctrl-C
+ }
+
+ if(strcmp(newp, toybuf) == 0)
+ return newp;
+ else error_msg("Passwords do not match.\n");
+ /*Failure Case */
+ free(newp);
+ return NULL;
+}
+
+
+void passwd_main(void)
+{
+ uid_t myuid;
+ struct passwd *pw;
+ struct spwd *sp;
+ char *name = NULL;
+ char *pass = NULL, *encrypted = NULL, *newp = NULL;
+ char *orig = (char *)"";
+ char salt[MAX_SALT_LEN];
+ int ret = -1;
+
+ myuid = getuid();
+ if((myuid != 0) && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
+ error_exit("You need to be root to do these actions\n");
+
+ pw = getpwuid(myuid);
+
+ if(!pw)
+ error_exit("Unknown uid '%u'",myuid);
+
+ if(toys.optargs[0])
+ name = toys.optargs[0];
+ else
+ name = xstrdup(pw->pw_name);
+
+ pw = getpwnam(name);
+ if(!pw) error_exit("Unknown user '%s'",name);
+
+ if(myuid != 0 && (myuid != pw->pw_uid))
+ error_exit("You need to be root to change '%s' password\n", name);
+
+ pass = pw->pw_passwd;
+ if(pw->pw_passwd[0] == 'x') {
+ /*get shadow passwd */
+ sp = getspnam(name);
+ if(sp)
+ pass = sp->sp_pwdp;
+ }
+
+
+ if(!(toys.optflags & (FLAG_l | FLAG_u | FLAG_d))) {
+ printf("Changing password for %s\n",name);
+ if(pass[0] == '!')
+ error_exit("Can't change, password is locked for %s",name);
+ if(myuid != 0) {
+ /*Validate user */
+
+ if(read_password(toybuf, sizeof(toybuf), "Origial password:")) {
+ if(!toys.optargs[0]) free(name);
+ return;
+ }
+ orig = toybuf;
+ if(verify_passwd(pass))
+ error_exit("Authentication failed\n");
+ }
+
+ orig = xstrdup(orig);
+
+ /*Get new password */
+ newp = new_password(orig, name);
+ if(!newp) {
+ free(orig);
+ if(!toys.optargs[0]) free(name);
+ return; //new password is not set well.
+ }
+
+ /*Encrypt the passwd */
+ if(!(toys.optflags & FLAG_a)) TT.algo = "des";
+
+ if(get_salt(salt))
+ error_exit("Error: Unkown encryption algorithm\n");
+
+ encrypted = crypt(newp, salt);
+ free(newp);
+ free(orig);
+ }
+ else if(toys.optflags & FLAG_l) {
+ if(pass[0] == '!')
+ error_exit("password is already locked for %s",name);
+ printf("Locking password for %s\n",name);
+ encrypted = xmsprintf("!%s",pass);
+ }
+ else if(toys.optflags & FLAG_u) {
+ if(pass[0] != '!')
+ error_exit("password is already unlocked for %s",name);
+
+ printf("Unlocking password for %s\n",name);
+ encrypted = xstrdup(&pass[1]);
+ }
+ else if(toys.optflags & FLAG_d) {
+ printf("Deleting password for %s\n",name);
+ encrypted = (char*)xzalloc(sizeof(char)*2); //1 = "", 2 = '\0'
+ }
+
+ /*Update the passwd */
+ if(pw->pw_passwd[0] == 'x')
+ ret = update_password("/etc/shadow", name, encrypted);
+ else
+ ret = update_password("/etc/passwd", name, encrypted);
+
+ if((toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
+ free(encrypted);
+
+ if(!toys.optargs[0]) free(name);
+ if(!ret)
+ error_msg("Success");
+ else
+ error_msg("Failure");
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-23 14:25:34 +0000