Cleanup pass on passwd, needs more testing.

1 files changed, 53 insertions, 128 deletions

diff --git a/toys/lsb/passwd.c b/toys/lsb/passwd.c
index 687d4c09..e23de1c6 100644
--- a/toys/lsb/passwd.c
+++ b/toys/lsb/passwd.c
@@ -26,10 +26,10 @@ config PASSWD_SAD
   default n
   depends on PASSWD
   help
-    Password changes are checked to make sure they don't include the entire
-    username (but not a subset of it), and the entire previous password
-    (but changing password1, password2, password3 is fine). This heuristic
-    accepts "aaaaaa" as a password.
+    Password changes are checked to make sure they're at least 6 chars long,
+    don't include the entire username (but not a subset of it), or the entire
+    previous password (but changing password1, password2, password3 is fine).
+    This heuristic accepts "aaaaaa" and "123456".
 */
 
 #define FOR_passwd
@@ -39,153 +39,78 @@ GLOBALS(
   char *algo;
 )
 
-static int str_check(char *s, char *p)
+// Sad advisory heuristic, won't find password1 password2 password3...
+static void weak_check(char *new, char *old, char *user)
 {
-  if (strnstr(s, p) || strnstr(p, s)) return 1;
-  return 0;
-}
-
-// Insane heuristic won't find password1 password2 password3...?
-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  && !strcmp(pass, pwd)) return 0;
-
-  return 1;
-}
+  char *msg = 0;
 
-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);
-  if (CFG_PASSWD_SAD) strength_check(newp, oldp, user);
-  if (read_password(toybuf, sizeof(toybuf), "Retype password:")) {
-    free(newp);
-    return NULL; //may be due to Ctrl-C
+  if (strlen(new) < 6) msg = "too short";
+  if (*new) {
+    if (strnstr(new, user) || strnstr(user, new)) msg = "user";
+    if (*old && (strnstr(new, old) || strnstr(old, new))) msg = "old";
   }
-
-  if (!strcmp(newp, toybuf)) return newp;
-  else error_msg("Passwords do not match.\n");
-  // Failure Case
-  free(newp);
-  return NULL;
+  if (msg) xprintf("BAD PASSWORD: %s\n",msg);
 }
 
 void passwd_main(void)
 {
   uid_t myuid;
-  struct passwd *pw;
+  struct passwd *pw = 0;
   struct spwd *sp;
-  char *name = NULL, *pass = NULL, *encrypted = NULL, *newp = NULL,
-       *orig = (char *)"", salt[MAX_SALT_LEN];
+  char *pass, *name, *encrypted = 0, salt[MAX_SALT_LEN];
   int ret = -1;
 
-  myuid = getuid();
-  if (myuid && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
-    error_exit("Not root");
-
-  pw = xgetpwuid(myuid);
-
-  if (*toys.optargs) name = toys.optargs[0];
-  else name = xstrdup(pw->pw_name);
-
-  pw = xgetpwnam(name);
-
-  if (myuid && (myuid != pw->pw_uid)) error_exit("Not root");
-
-  pass = pw->pw_passwd;
-  if (pw->pw_passwd[0] == 'x') {
-    //get shadow passwd
-    sp = getspnam(name);
-    if (sp) pass = sp->sp_pwdp;
+  // If we're root or not -lud, load specified user. Exit if not allowed.
+  if (!(myuid = getuid()) || !(toys.optflags&(FLAG_l|FLAG_u|FLAG_d))) {
+    if (*toys.optargs) pw = xgetpwnam(*toys.optargs);
+    else pw = xgetpwuid(myuid);
   }
+  if (!pw || (myuid && (myuid != pw->pw_uid))) error_exit("Not root");
 
+  // Get password from /etc/passwd or /etc/shadow
+  // TODO: why still support non-shadow passwords...?
+  name = pw->pw_name;
+  if (*(pass = pw->pw_passwd)=='x' && (sp = getspnam(name))) pass = sp->sp_pwdp;
 
-  if (!(toys.optflags & (FLAG_l | FLAG_u | FLAG_d))) {
-    
-    if (!(toys.optflags & FLAG_a)) TT.algo = "des";
-    if (get_salt(salt, TT.algo) == -1)
-      error_exit("Error: Unkown encryption algorithm\n");
+  if (toys.optflags & FLAG_l) {
+    if (*pass=='!') error_exit("already locked");
+    printf("Locking '%s'\n", name);
+    encrypted = xmprintf("!%s", pass);
+  } else if (toys.optflags & FLAG_u) {
+    if (*pass!='!') error_exit("already unlocked");
+    printf("Unlocking '%s'\n", name);
+    encrypted = pass+1;
+  } else if (toys.optflags & FLAG_d) {
+    printf("Deleting password for '%s'\n", name);
+    encrypted = "";
+  } else {
+    if (get_salt(salt, TT.algo ? TT.algo : "des")<0)
+      error_exit("bad -a '%s'", TT.algo);
 
-    printf("Changing password for %s\n",name);
-    if (myuid && pass[0] == '!')
-      error_exit("Can't change, password is locked for %s",name);
+    printf("Changing password for %s\n", name);
     if (myuid) {
-      //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");
-    }
+      if (*pass=='!') error_exit("'%s' locked", name);
 
-    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.
+      if (read_password(toybuf+2048, 2048, "Old password:")) return;
+      pass = crypt(toybuf+2048, pw->pw_passwd);
+      if (!pass || strcmp(pass, pw->pw_passwd)) error_exit("No");
     }
 
-    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 = xmprintf("!%s",pass);
-  } else if (toys.optflags & FLAG_u) {
-    if (pass[0] != '!') error_exit("password is already unlocked for %s",name);
+    if (read_password(toybuf, 2048, "New password:")) return;
 
-    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 = xstrdup(""); //1 = "", 2 = '\0'
+    if (CFG_PASSWD_SAD) weak_check(toybuf, toybuf+2048, name);
+    if (read_password(toybuf+2048, 2048, "Retype password:")) return;
+    if (strcmp(toybuf, toybuf+2048)) error_exit("Passwords do not match.");
+
+    encrypted = crypt(toybuf, salt);
   }
 
   // Update the passwd
-  if (pw->pw_passwd[0] == 'x')
-    ret = update_password("/etc/shadow", name, encrypted);
-  else ret = update_password("/etc/passwd", name, encrypted);
+  ret = update_password(*pw->pw_passwd=='x' ? "/etc/shadow" : "/etc/passwd",
+    name, encrypted);
 
-  if ((toys.optflags & (FLAG_l | FLAG_u | FLAG_d))) free(encrypted);
+  if (ret) error_msg("Failure");
+  else fprintf(stderr, "Success\n");
 
-  if (!toys.optargs[0]) free(name);
-  if (!ret) error_msg("Success");
-  else error_msg("Failure");
+  if (CFG_TOYBOX_FREE && (toys.optflags & FLAG_l)) free(encrypted);
 }