<HTML ><HEAD ><TITLE >mcrypt_generic_init</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="PHP Manual" HREF="index.html"><LINK REL="UP" TITLE="Mcrypt Encryption Functions" HREF="ref.mcrypt.html"><LINK REL="PREVIOUS" TITLE="mcrypt_generic_end" HREF="function.mcrypt-generic-end.html"><LINK REL="NEXT" TITLE="mcrypt_generic" HREF="function.mcrypt-generic.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=ISO-8859-1"></HEAD ><BODY CLASS="refentry" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >PHP Manual</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.mcrypt-generic-end.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.mcrypt-generic.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.mcrypt-generic-init" ></A >mcrypt_generic_init</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN49174" ></A ><P > (PHP 4 >= 4.0.2)</P >mcrypt_generic_init -- This function initializes all buffers needed for encryption</DIV ><DIV CLASS="refsect1" ><A NAME="AEN49177" ></A ><H2 >Description</H2 >int <B CLASS="methodname" >mcrypt_generic_init</B > ( resource td, string key, string iv)<BR ></BR ><P > The maximum length of the key should be the one obtained by calling <A HREF="function.mcrypt-enc-get-key-size.html" ><B CLASS="function" >mcrypt_enc_get_key_size()</B ></A > and every value smaller than this is legal. The IV should normally have the size of the algorithms block size, but you must obtain the size by calling <A HREF="function.mcrypt-enc-get-iv-size.html" ><B CLASS="function" >mcrypt_enc_get_iv_size()</B ></A >. IV is ignored in ECB. IV MUST exist in CFB, CBC, STREAM, nOFB and OFB modes. It needs to be random and unique (but not secret). The same IV must be used for encryption/decryption. If you do not want to use it you should set it to zeros, but this is not recommended. The function returns a negative value on error. </P ><P > You need to call this function before every call to <A HREF="function.mcrypt-generic.html" ><B CLASS="function" >mcrypt_generic()</B ></A > or <A HREF="function.mdecrypt-generic.html" ><B CLASS="function" >mdecrypt_generic()</B ></A >. </P ><P > See for an example <A HREF="function.mcrypt-module-open.html" ><B CLASS="function" >mcrypt_module_open()</B ></A > and the entry on <A HREF="function.mcrypt-generic-deinit.html" ><B CLASS="function" >mcrypt_generic_deinit()</B ></A >. </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="function.mcrypt-generic-end.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.mcrypt-generic.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >mcrypt_generic_end</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.mcrypt.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >mcrypt_generic</TD ></TR ></TABLE ></DIV ></BODY ></HTML >