php中生成随机字符串的函数

介绍一篇关于php中生成随机加密的函数，有需要朋友可以参考一下，是一个自定了的函数不是系统自带的。

代码如下

复制代码

function encrypt_str( $TXT, $KEY ) {         srand( ( double )microtime( ) * 1000000 );         $ENCRYPT_KEY = md5( rand( 0, 32000 ) );         $CTR = 0;         $TMP = "";         $I = 0;         for ( ;    $I         {                 if ( $CTR == strlen( $ENCRYPT_KEY ) )                 {                         $CTR = 0;                 }                 $TMP .= substr( $ENCRYPT_KEY, $CTR, 1 ).( substr( $TXT, $I, 1 ) ^ substr( $ENCRYPT_KEY, $CTR, 1 ) );                 ++$CTR;         }         return keyed_str( $TMP, $KEY ); } function decrypt_str( $TXT, $KEY ) {         $TXT = keyed_str( $TXT, $KEY );         $TMP = "";         $I = 0;         for ( ;    $I         {                 $MD5 = substr( $TXT, $I, 1 );                 ++$I;                 $TMP .= substr( $TXT, $I, 1 ) ^ $MD5;         }         return $TMP; } function keyed_str( $TXT, $ENCRYPT_KEY ) {         $ENCRYPT_KEY = md5( $ENCRYPT_KEY );         $CTR = 0;         $TMP = "";         $I = 0;         for ( ;    $I         {                 if ( $CTR == strlen( $ENCRYPT_KEY ) )                 {                         $CTR = 0;                 }                 $TMP .= substr( $TXT, $I, 1 ) ^ substr( $ENCRYPT_KEY, $CTR, 1 );                 ++$CTR;         }         return $TMP; }