PHP中加密解密函数与DES加密解密实例

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"; echo '密文：',$encrypt."

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"; echo '译文：',$decrypt."

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";

function DES( $key,$iv=0 ) {
//key长度8例如:1234abcd
$this->key = $key;
if( $iv == 0 ) {
$this->iv = $key;
} else {
$this->iv = $iv; //mcrypt_create_iv ( mcrypt_get_block_size (MCRYPT_DES,MCRYPT_MODE_CBC),MCRYPT_DEV_RANDOM );
}
}

function encrypt($str) {
//加密，返回大写十六进制字符串
$size = mcrypt_get_block_size ( MCRYPT_DES,MCRYPT_MODE_CBC );
$str = $this->pkcs5Pad ( $str,$size );
return strtoupper( bin2hex( mcrypt_cbc(MCRYPT_DES,$this->key,$str,MCRYPT_ENCRYPT,$this->iv ) ) );
}

function decrypt($str) {
//解密
$strBin = $this->hex2bin( strtolower( $str ) );
$str = mcrypt_cbc( MCRYPT_DES,$strBin,MCRYPT_DECRYPT,$this->iv );
$str = $this->pkcs5Unpad( $str );
return $str;
}

function hex2bin($hexData) {
$binData = "";
for($i = 0; $i < strlen ( $hexData ); $i += 2) {
$binData .= chr ( hexdec ( substr ( $hexData,$i,2 ) ) );
}
return $binData;
}

function pkcs5Pad($text,$blocksize) {
$pad = $blocksize - (strlen ( $text ) % $blocksize);
return $text . str_repeat ( chr ( $pad ),$pad );
}

function pkcs5Unpad($text) {
$pad = ord ( $text {strlen ( $text ) - 1} );
if ($pad > strlen ( $text ))
return false;
if (strspn ( $text,chr ( $pad ),strlen ( $text ) - $pad ) != $pad)
return false;
return substr ( $text,- 1 * $pad );
}
}
?>