Study Note | SQL Injection

Treep — Mon, 27 Nov 2023 14:44:09 +0000

Wide Byte Injection

For some wide byte charset, such as GBK and GB2312, special character (the character expect English letter) will be 2 bytes. So, we could prevent the quotation mark (') from being escaped by adding %df to make the slash used to escape single quotation mark be regarded as a special character through combining with %df.

For instance, we have a original string admin' , after processing by addslashes() in PHP, it will be admin\' now. So, we can transform the original string to admin%df' , it will be escaped as admin%df\' , then the %df and \ will be combined to a wide byte. So, we have a single quotation that is not escaped now.

Error Injection

Description

Use EXTRACTVALUE method to get sensitive information of target database. For the principle, EXTRACTVALUE(xml_code_or_file, xpath) will display result of xpath parameter if the grammar of XPath is invalid. So, you could use the symbol that will cause wrong grammar in XPath, such as symbol ~ or 0x7e.

Common Usage

View name of database: SELECT EXTRACTVALUE(1, CONCAT(0x7e, (SELECT DATABASE())))
View names of tables: SELECT EXTRACTVALUE(1, CONCAT(0x7e, (SELECT GROUP_CONCAT(table_name) FROM information_schema.tables WHERE table_schema=DATABASE())))
View names of columns: SELECT EXTRACTVALUE(1, CONCAT(0x7e, (SELECT GROUP_CONCAT(column_name) FROM information_schema.columns WHERE table_name="table_name")))
View data of table: SELECT ECTRACTVALUE(1, CONCAT(0x7e, (SELECT GROUP_CONCAT(column_name) FROM table_name)))

Attention

The maximum length of EXTRACTVALUE 's result is 32, SUBSTR() or LIMIT should be used when the length is greater than 32.

Convert PHP Project to Android App

Treep — Thu, 27 Jul 2023 07:09:21 +0000

Before Beginning

PHP is an excellent choice for beginners to learn about development of Web App. For a PHP learner, if you want to share your works to others, making it to an Android App is a best choice without establishing a website. Don't worry about matters, what we need is just a mobile phone!

HopWeb App can just make an Android App from a PHP project.

Content

Preparations
Preview Project
Customize Your App
Install & Share Your App
FAQ

Preparations

HopWeb (Version 2.7.0 or above, download via Google Play)
An Android phone with Android 8.0 and above. (64-bit ARM CPU is also necessary.)

Create or Import A PHP project on HopWeb

Open HopWeb, create a PHP project by pressing [Create Project] button. And then check "PHP Template".

If you want to import an existing PHP project, you can press [IMPORT PROJECT] button on "Create Project" dialog, and then choose the ZIP file of your project.
Furthermore, you could download a project that is shared by others on ideaSky. As a demonstration, I downloaded the resource named "Simple User System". You can find it by searching RID: IDEA-10002.

Go back Home after downloading, and you can see the project. Just open it.

Preview Project

HopWeb has a built-in PHP environment, so that you can preview the PHP project directly through HopWeb.

Touch the "≡" icon in the left to open project manager.

Click index.html or index.php to open the file and preview it by the green triangle icon in the bottom right corner.
Let's register an account, and log in then.

You can find the registered accounts information in the data folder. Clear the content of file users.json to delete registered accounts.

Customize Your App

If you want to use a different icon rather than the default, you need to import the icon image file to the project first.

Click [Import]-[Import Media File], and choose an image file you like. You can see the image file you imported in the file list after importing.

Click [Publish Your Website], and click [Convert to Android App] then.

Click [Application Icon] and choose the image file we've just imported.

Modify other information of the App to your liking. Don't forget to check [Carry PHP Environment].

After customizing, press the OK icon at the bottom of the page to produce the APK installer file.

Install & Share Your App

After conversion, go back to the project manager, and refresh the file list by swiping it down. You can see the produced APK file.

You could open the system file manager App and locate into "Internal storage -> Venter -> HopWeb -> Simple User System", and you will see the APK file. Install by clicking on it.

Open your App, and the webpage has become a client application. The PHP code can also run as normal.

FAQ

There is an error when open the produced App: The port of PHP environment may be incorrect. You can modify the port in the Convert to Android App page. The range of ports is 1024 ~ 65535. Common ports like 8080 are not recommended.
The PHP project used MySQL: HopWeb will support database server like MySQL in the future version, but not currently supported.
Incompatible PHP version: The PHP version of HopWeb 2.7.0 is 8.2.8. If your PHP project uses some syntactic features of PHP 7, there may be some problems.
System requirement of produced App: Require Android 6.0 and above systems. The architecture of CPU must be ARM 64.

DEV Community: Treep