Improved Security with passwords read from stdin, length limited user-id

1 files changed, 83 insertions, 50 deletions

diff --git a/www/commission/index.php b/www/commission/index.php
index 3e87e7a..ef8b68d 100644
--- a/www/commission/index.php
+++ b/www/commission/index.php
@@ -27,7 +27,7 @@ openlog("Commission:", LOG_PID | LOG_PERROR, LOG_LOCAL0);
 
 // uid number must be 1000 or larger.
 function chk_username($userid) {
-    $cmd = "/usr/bin/id -u " . $userid . " 2>/dev/null";
+    $cmd = "/usr/bin/id -u \"" . $userid . "\" 2>/dev/null";
     syslog(LOG_ALERT, "/usr/bin/id cmd: $cmd");
     $handle = popen($cmd, 'r');
     $result = trim(fread($handle, 4192));
@@ -59,16 +59,22 @@ if($_SERVER["REQUEST_METHOD"] == "POST"){
         goto err_exit;
     }
 
-    $save_password = trim($_POST["save_password"]);
+    $save_password = $_POST["save_password"];
 
 
     syslog(LOG_ALERT, "Enter post: save_password = $save_password");
 
+    $username = trim($_POST["username"]);
+    $userlen = strlen($username);
     // Validate username
-    if(strlen(trim($_POST["username"])) == 0){
+    // Be generous on the character length of the username
+    // in case it is some kind of character encoding scheme.
+    // useradd should catch it if the length is a little off.
+    if($userlen == 0) {
         $username_err = "Please enter a username.";
+    } elseif ($userlen > 80) {
+        $username_err = "mLinux username must not exceed 32 characters";
     } else {
-        $username = trim($_POST["username"]);
         syslog(LOG_ALERT, "Enter username check: $username");
         $id = chk_username($username);
         syslog(LOG_ALERT, "after username check: chk_username $id");
@@ -77,26 +83,45 @@ if($_SERVER["REQUEST_METHOD"] == "POST"){
         }
     }
 
-    // Validate password
-    if(strlen(trim($_POST["password"])) == 0){
+    // Validate password.  Password length is not set in
+    // Linux.  It depends on how much memory we have.
+    // To avoid unknown issues, reject if > 4096
+    $tmpfile = tempnam("/var/volatile/tmp","commission");
+    $password = $_POST["password"];
+    $passlen = strlen($password);
+    $save_passwordlen = strlen($save_password);
+    syslog(LOG_ALERT, "passlen: $passlen, save_password len: $save_passwordlen");
+    syslog(LOG_ALERT, "password: $password, save_password: $save_password");
+    if ($passlen == 0) {
         $password_err = "Please enter a password.";
         $mismatch = 0;
+    } elseif ($passlen > 4096) {
+        $password_err = "Too long. Limit password length to 4096 characters";
+        $password = "";
+
     } else {
-        $password = trim($_POST["password"]);
-        if (strlen($save_password) == 0) {
+        if ($save_passwordlen === 0) {
             $mismatch = 0;
-            $cmd = "echo '" . $password . "' | /usr/bin/pwscore 2>&1";
-            $handle = popen($cmd, 'r');
-            $result = trim(fread($handle,4192));
-            if (pclose($handle) === 0) {
-                $pwdscore = "Password score: " . $result;
+            $cmd = "/usr/bin/pwscore >$tmpfile 2>&1";
+            $handle = popen($cmd, 'w');
+            fwrite($handle,$password);
+            $status = pclose($handle);
+            
+	    $result2 = file_get_contents($tmpfile);
+            if (strlen($result2) > 0)
+                syslog(LOG_ALERT, "read pwscore log: status: $status result: $result2");
+            else
+                syslog(LOG_ALERT, "pwscore has no results!");
+
+            if ($status === 0) {
+                $pwdscore = "Password score: " . $result2;
                 $save_password = $password;
                 $password = "";
                 $conftxt = "Re-Enter";
             } else {
                 $conftxt = "Re-Enter";
-                $password_err = $result .
-                    ". Confirm password if you really want this." .
+                $password_err = $result2 .
+                    " Confirm password if you really want this." .
                     " Click reset to start again";
                 $save_password = $password;
                 $password = "";
@@ -106,19 +131,24 @@ if($_SERVER["REQUEST_METHOD"] == "POST"){
         }
     }
 
-    if ((strlen($password) != 0) && ($password === $save_password) && (strlen($username) != 0)) {
-        syslog(LOG_ALERT, "Have password: $password username: $password");
+    if (($passlen != 0) && ($password === $save_password))
+        $mismatch = 0;
+    
+    if (($mismatch === 0) && ($passlen > 0) && ($save_passwordlen > 0)) {
+        syslog(LOG_ALERT, "Have password: $password username: $username");
         if((strlen($username_err) == 0) && (strlen($password_err) == 0) && (strlen($confirm_password_err) == 0)){
             // Create user in sudo group
-            $cmd = "/usr/sbin/useradd -U -m -G sudo,dialout,disk -s /bin/bash " . $username . " 2>&1";
+            $cmd = "/usr/sbin/useradd -U -m -G sudo,dialout,disk -s /bin/bash -- \"" . $username . "\" 2>&1";
             syslog(LOG_ALERT, "useradd cmd: $cmd");
             $handle = popen($cmd, 'r');
             $username_err = trim(fread($handle, 4192));
             $status = pclose($handle);
             syslog(LOG_ALERT, "useradd: status: $status result: $result");
             $uid = chk_username($username);
-            $cmd = "/usr/bin/id " . $username . " 2>/dev/null";
-            if (! ($uid > 999)) {
+            if ($uid === -1) {
+                syslog(LOG_ALERT, "useradd: $status");
+                goto err_exit;
+            } elseif (! ($uid > 999)) {
                 syslog(LOG_ALERT, "useradd: system user-id cannot be chosen: $username uid: $uid");
                 $username_err = "useradd: system user-id cannot be chosen: $username uid: $uid";
                 $username = "";
@@ -126,29 +156,38 @@ if($_SERVER["REQUEST_METHOD"] == "POST"){
                 $password = "";
                 goto err_exit;
             } // Must have uid > 999
-            $tmpfile = tempnam("/var/volatile/tmp","commission");
 
-            $cmd = "/usr/bin/passwd " . $username . " 2>&1 >$tmpfile";
+            $cmd = "/usr/bin/passwd \"" . $username . "\" 2>&1 >$tmpfile";
             $handle = popen($cmd, 'w');
             $pwdtxt = $password . "\n" . $password;
             fwrite($handle, $pwdtxt);
             $status = pclose($handle);
             syslog(LOG_ALERT, "set passwd: status: $status result: $result");
 
-            $cmd = "/bin/cat $tmpfile";
-            $handle = popen($cmd, 'r');
-            $result2 = trim(fread($handle, 4192));
-            $status2 = pclose($handle);
-            if (($result2 != 0) || (strlen($result2) > 0))
-                syslog(LOG_ALERT, "read passwd log: status: $status2 result: $result2");
+	    $result2 = file_get_contents($tmpfile);
+            if (strlen($result2) > 0) {
+                syslog(LOG_ALERT, "passwd log: status: $status2 result: $result2");
+            }
+                
+            $cmd = "/sbin/mts-ubpasswd -up >$tmpfile 2>&1";
+            $handle = popen($cmd, 'w');
+            fwrite($handle,$password);
+            $status = pclose($handle);
+            
+	    $result3 = file_get_contents($tmpfile);
 
-            $cmd = "/sbin/mts-ubpasswd -u " . $password;
-            $handle = popen($cmd, 'r');
-            $result3 = trim(fread($handle, 4192));
-            $status3 = pclose($handle);
-            if ($status != 0)
-                syslog(LOG_ALERT, "mts-ubpasswd: status: $status result: $result");
-            else
+            // Delete the password entry log
+            $handle = fopen($tmpfile, 'w');
+            ftruncate($handle,0);
+            fclose($handle);
+
+            if (strlen($result2) > 0)
+                syslog(LOG_ALERT, "read mts-ubpasswd log: result: $result2");
+            
+            if ($status != 0) {
+                syslog(LOG_ALERT, "mts-ubpasswd failed: status: $status");
+                syslog(LOG_ALERT, "mts-ubpasswd failed: result: $result3");
+            } else  // Dont print if successful or password is in the log.
                 syslog(LOG_ALERT, "mts-ubpasswd: set u-boot password");
 
             if ($status == 0) {
@@ -156,25 +195,19 @@ if($_SERVER["REQUEST_METHOD"] == "POST"){
                 $password_err = $result2;
                 $username_err = $result;
                 // Disable commissioning
-                $cmd = "echo 'ENABLED=\"no\"' >/run/mt-commission 2>&1";
+                $data = 'ENABLED=\"no\"';
+                file_put_contents("/run/mt-commission",$data);
+
+                // shut off web server
+                $cmd = "/usr/sbin/start-stop-daemon -S -p /var/run/commissionoff.pid -b -a /bin/bash -- -c " .
+                    "/usr/libexec/commission/off.sh";
+                syslog(LOG_ALERT, "turn off web server: command: $cmd");
                 $handle = popen($cmd, 'r');
                 $result = trim(fread($handle, 4192));
                 $status = pclose($handle);
                 if ($status > 0) {
-                    syslog(LOG_ALERT, "configure commissioning off failure: command: $cmd");
-                    syslog(LOG_ALERT, "passwd: status: $status result: $result");
-                } else {
-                    // shut off web server
-                    $cmd = "/usr/sbin/start-stop-daemon -S -p /var/run/commissionoff.pid -b -a /bin/bash -- -c " .
-                        "/usr/libexec/commission/off.sh";
-                    syslog(LOG_ALERT, "turn off web server: command: $cmd");
-                    $handle = popen($cmd, 'r');
-                    $result = trim(fread($handle, 4192));
-                    $status = pclose($handle);
-                    if ($status > 0) {
-                        syslog(LOG_ALERT, "turn off commissioning service: command: $cmd");
-                        syslog(LOG_ALERT, "stopping service: status: $status result: $result");
-                    }
+                    syslog(LOG_ALERT, "turn off commissioning service: command: $cmd");
+                    syslog(LOG_ALERT, "stopping service: status: $status result: $result");
                 }
             } else {
                 $finished = "Errors: " . $result;