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PHP uses crypt() function for encryption sample code

怪我咯Original: 2017-07-13 14:50:361114browse

The crypt() function returns a string encrypted using the DES, Blowfish, or MD5 algorithm.

This function behaves differently on different operating systems, and some operating systems support more than one algorithm type. At installation time, PHP checks what algorithms are available and what algorithms are used.

The specific algorithm depends on the format and length of the salt parameter. Salt can make encryption more secure by increasing the number of strings generated by a specific string using a specific encryption method.

This article mainly introduces in detail the use of crypt() function for encryption in PHP

1. Code

<?php 
 $str = &#39;应用crypt()函数进行单向加密!&#39;;     //声明字符串变量$str 
 echo &#39;加密前$str的值为：&#39;.$str; 
 $crypttostr = crypt($str);      //对变量$str加密 
 echo &#39;<p>加密后$str的值为：&#39;.$crypttostr;  //输出加密后的变量 
?

2. Running results

The parameters do not contain salt, and the ciphertext obtained after each encryption is different.
The value of $str before encryption is: apply the crypt() function for one-way encryption!
The value of $str after encryption is: $1$Re4.Gg4.$D.yd00xX0fFfIfp6KrKGN0

3. Code

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> 
<title>使用crypt函数进行数据验证</title> 
<style type="text/css"> 
<!-- 
body,td,th { 
 font-size: 12px; 
} 
body { 
 margin-left: 10px; 
 margin-top: 10px; 
 margin-right: 10px; 
 margin-bottom: 10px; 
} 
.STYLE1 { 
 font-size: 14px; 
 font-weight: bold; 
} 
--> 
</style> 
</head> 
<body> 
<p align="center"> 
<?php 
 $conn = mysql_connect("localhost","root","root") or die("数据库链接错误".mysql_error()); 
 mysql_select_db("db_database21",$conn) or die("数据库访问错误".mysql_error()); 
 mysql_query("set names gb2312"); 
?> 
</p> 
<table width="777" height="587" border="0" align="center" cellpadding="0" cellspacing="0" background="images/bg.jpg"> 
 <tr> 
 <td width="149" height="200"> </td> 
 <td width="448"> </td> 
 <td width="158"> </td> 
 </tr> 
 <tr> 
 <td height="187"> </td> 
 <td align="center" valign="middle"> <form id="form1" name="form1" method="post" action="index.php"> 
 <table height="129" border="0" cellpadding="0" cellspacing="0"> 
  <tr> 
   <td width="100" height="30" align="right" valign="middle" scope="col"><span class="STYLE1">用户名：</span></td> 
  <td width="100" height="30" align="left" valign="middle" scope="col"><label for="textfield"></label> 
  <input name="username" type="text" id="username" size="24" /></td> 
  <td width="100" align="center" valign="middle" scope="col"> </td> 
  </tr> 
  <tr> 
  <td height="30" align="right" valign="middle" class="STYLE1" scope="col">密码：</td> 
  <td height="30" align="left" valign="middle" scope="col"><input name="password" type="password" id="password" size="25" /></td> 
  <td align="center" valign="middle" scope="col"> </td> 
  </tr> 
  <tr> 
  <td height="40" colspan="3" align="center" valign="middle" scope="col"><input type="image" name="imageField" src="images/bg2.JPG" />   
     <input type="image" name="imageField2" src="images/bg1.JPG" onclick="form.reset();return false;" /></td> 
  </tr> 
 </table> 
 </form> 
 <?php 
 if(trim($_POST[username])!= "" and trim($_POST[password])!= ""){ 
  $usr = crypt(trim($_POST[username]),$_POST[username]); 
  $pwd = crypt(trim($_POST[password]),$_POST[password]); 
  $sql = "select * from tb_user where username = &#39;".$usr."&#39; and password=&#39;".$pwd."&#39;"; 
  $rst = mysql_query($sql,$conn); 
  $result=mysql_num_rows($rst); 
  if($result>0){ 
   echo "<font color=&#39;red&#39;>用户登录成功。</font>"; 
  }else{ 
   echo "<font color=&#39;green&#39;>用户登录失败!</font>"; 
  } 
 }else{ 
  echo "请认真填写用户名和密码！"; 
 } 
?></td> 
 <td> </td> 
 </tr> 
 <tr> 
 <td height="200"> </td> 
 <td> </td> 
 <td> </td> 
 </tr> 
</table> 
</body> 
</html>

4. Running results

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