<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >mcrypt_generic_init</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="PHP 手册" 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=UTF-8"></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 手册</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.mcrypt-generic-end.html" ACCESSKEY="P" >上一页</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" >下一页</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="AEN115735" ></A ><P > (PHP 4 >= 4.0.2, PHP 5)</P >mcrypt_generic_init -- This function initializes all buffers needed for encryption</DIV ><DIV CLASS="refsect1" ><A NAME="AEN115738" ></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. </P ><P > The function returns a negative value on error, -3 when the key length was incorrect, -4 when there was a memory allocation problem and any other return value is an unknown error. If an error occurs a warning will be displayed accordingly. <TT CLASS="constant" ><B >FALSE</B ></TT > is returned if incorrect parameters were passed. </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 >. </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" >上一页</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >起始页</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.mcrypt-generic.html" ACCESSKEY="N" >下一页</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" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >mcrypt_generic</TD ></TR ></TABLE ></DIV ></BODY ></HTML >