<HTML ><HEAD ><TITLE >mcrypt_encrypt</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_enc_self_test" HREF="function.mcrypt-enc-self-test.html"><LINK REL="NEXT" TITLE="mcrypt_generic_deinit" HREF="function.mcrypt-generic-deinit.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-enc-self-test.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-deinit.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.mcrypt-encrypt" ></A >mcrypt_encrypt</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN49086" ></A ><P > (PHP 4 >= 4.0.2)</P >mcrypt_encrypt -- Encrypts plaintext with given parameters</DIV ><DIV CLASS="refsect1" ><A NAME="AEN49089" ></A ><H2 >Description</H2 >string <B CLASS="methodname" >mcrypt_encrypt</B > ( string cipher, string key, string data, string mode [, string iv])<BR ></BR ><P > <B CLASS="function" >mcrypt_encrypt()</B > encrypts the data and returns the encrypted data. </P ><P > <TT CLASS="parameter" ><I >Cipher</I ></TT > is one of the MCRYPT_ciphername constants of the name of the algorithm as string. </P ><P > <TT CLASS="parameter" ><I >Key</I ></TT > is the key with which the data will be encrypted. If it's smaller that the required keysize, it is padded with '<TT CLASS="literal" >\0</TT >'. It is better not to use ASCII strings for keys. It is recommended to use the mhash functions to create a key from a string. </P ><P > <TT CLASS="parameter" ><I >Data</I ></TT > is the data that will be encrypted with the given cipher and mode. If the size of the data is not n * blocksize, the data will be padded with '<TT CLASS="literal" >\0</TT >'. The returned crypttext can be larger that the size of the data that is given by <TT CLASS="parameter" ><I >data</I ></TT >. </P ><P > <TT CLASS="parameter" ><I >Mode</I ></TT > is one of the MCRYPT_MODE_modename constants of one of "ecb", "cbc", "cfb", "ofb", "nofb" or "stream". </P ><P > The <TT CLASS="parameter" ><I >IV</I ></TT > parameter is used for the initialisation in CBC, CFB, OFB modes, and in some algorithms in STREAM mode. If you do not supply an IV, while it is needed for an algorithm, the function issues a warning and uses an IV with all bytes set to '<TT CLASS="literal" >\0</TT >'. </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN49126" ></A ><P ><B >Example 1. <B CLASS="function" >mcrypt_encrypt()</B > Example</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="php" ><?php $iv = mcrypt_create_iv (mcrypt_get_iv_size (MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND); $key = "This is a very secret key"; $text = "Meet me at 11 o'clock behind the monument."; echo strlen ($text)."\n"; $crypttext = mcrypt_encrypt (MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_ECB, $iv); echo strlen ($crypttext)."\n"; ?></PRE ></TD ></TR ></TABLE ><P > The above example will print out: <TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="screen" >42 64</PRE ></TD ></TR ></TABLE > </P ></DIV ></TD ></TR ></TABLE > </P ><P > See also <A HREF="function.mcrypt-module-open.html" ><B CLASS="function" >mcrypt_module_open()</B ></A > for a more advanced API and an example. </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-enc-self-test.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-deinit.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >mcrypt_enc_self_test</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_deinit</TD ></TR ></TABLE ></DIV ></BODY ></HTML >