Find answers to frequently asked questions and read through some tips and tricks related to all Setasign PHP products.
All SetaPDF APIs are written in pure PHP and does not need any other libraries installed except a PHP environment of a version later than 4.3 (until 2010) and an installed Zend Optimizer or installed Ioncube loader.
All releases since 2010 require PHP 5.
As shown in the next paragraph, it is also recommended to install MCrypt.
The SetaPDF APIs have their own integrated RC4 function for encrypting and decrypting the contents of a PDF file. For performance reasons, the APIs initially tries to use the MCrypt library, if that is installed. If MCrypt is available, the APIs require the arcfour algorithm. The use of MCrypt increases the performance by up to 90% if encryption or decryption is needed. If MCrypt is not available, the APIs automatically fall back to their internal RC4 function.
Depending on the file size of the PDF files to be processed, some adjustment to the php.ini directives max_execution_time and memory_limit are recommended.
For performance optimization, all SetaPDF APIs provides a caching system that prevents the unnecessary reparsing of PDF files.
To use the AES algorithm for encryption MCrypt is required!
Furthermore for AES encryption with a 256-bit key the API needs the hash()-function which is available since PHP 5.1.2 or through PECL.