P day 6 PHP and mysqlweb Development

Chapter 2 Web Application Security

Chapter 17 authentication using PHP and MySQL...

Password hash encryption ,,,

Shal (); returns a pseudo-random string of 40 bytes ....

MySQL also provides the SHA-1 algorithm.  
Sha1 ('value ');

Chapter 18 Use PHP and MySQL for security transactions

Some technologies that shield user input

1. You must use addslashes () to filter user data before it is inserted into the database. Use the stripslashes () function to return the data to the original form.

2. Enable magic_quotes_gpc and magic_quotes_runtime in PHP. ini.

3. When the number of users is passed to system () or exec (), the escapeshellcmd () function must be used to filter out malicious commands.

4. Use strip_tags () to remove HTML and PHP tags from strings to prevent users from embedding malicious scripts into user information.

5. Use htmlspecialchars () to convert any script tag to harmless characters.
<Convert to $ lt;

 

 

 

Article 4 advanced PHP Technology

Chapter 4 interaction with file systems and servers

File Upload

First, you need to know several configurations in PHP. ini.

File_uploads       
Upload allowed?             
Default on

Upload_tmp_dir     
Folder when files are uploaded           
 Null

Upload_max_filesize
Maximum file size allowed to be uploaded        
2 m

Post_max_size      
The largest amount of data uploaded through post  
8 m

 Form

<Input type = "hidden" name = "max_file_size"
Value = "10000000"/> set the maximum length of the uploaded file.

The information of the uploaded file is stored in the super Global Array $ _ file.

$ _ File ["name of the file in the upload form"] ['tmp _ name'] location where the file is stored on the Web Server

['Name'] file name ['SIZE'] File Size ['type'] File's mine type ['error'] any error code related to File Upload

You also need to determine whether it is an uploaded file function. 
Is_upload_file ()

Move the uploaded file move_upload_file ()

Basename ('path', 'filter characters ')

Echo
'File upload error code: '. $ _ FILES ['userfile'] ['error'].' <br
/> ';
Echo 'file upload path: '. $ _ FILES ['userfile'] ['tmp _ name'].' <br
/> ';
Echo 'file upload name: '. $ _ FILES ['userfile'] ['name'].' <br
/> ';
Echo 'file size: '. $ _ FILES ['userfile'] ['SIZE'].' <br
/> ';
Echo 'file type: '. $ _ FILES ['userfile'] ['type'].' <br
/> ';

 

File Upload error code: 0
File Upload path: C: \ WINDOWS \ temp \ php9b. tmp
File Upload name: install.html
Size: 2867
File Type: text/html

Directory reading

Opendir (directory name) Open a directory 
Flase! === ($ File = readdir () read a directory
Last closedir ()Rewinddir () restores the read file to the start directory.