PHP-密码学算法及其应用-对称密码算法

mcrypt support: enabled
Version:  2.5.8  
Api No: 20021217  
Supported ciphers:  cast-128 gost rijndael-128 twofish arcfour cast-256 loki97 rijndael-192 saferplus wake blowfish-compat des rijndael-256 serpent xtea blowfish enigma rc2 tripledes  
Supported modes:  cbc cfb ctr ecb ncfb nofb ofb stream  

resource mcrypt_module_open ( string algorithm, string algorithm_directory, string mode, string mode_directory)

<?php
    $key = "security matrix";  //密钥
    $input = "mathmatica sounds very terrible!"; //明文
    
    //加密
    $td = mcrypt_module_open(‘rijndael-256‘, ‘‘, ‘cbc‘, ‘‘); //创建加密环境
    $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); //由于采用了cbc模式，我们需要一个初始化向量iv。
    mcrypt_generic_init($td, $key, $iv); //初始化加密算法，当算法模式是ecb时候，会自动忽略iv
    $encrypted_out_data = mcrypt_generic($td, $input);  //执行加密
    mcrypt_generic_deinit($td);  //释放加密算法资源      
    mcrypt_module_close($td);    //关闭加密环境，释放资源
    echo "明文是:$input";
    echo ‘<br>‘;
    echo "密钥是:$key";
    echo ‘<br>‘;
    echo "密文是:$encrypted_out_data";
    echo ‘<br>‘;
    //解密，由于$iv没有被清掉，所以我们还可以继续用这个。实际使用中一定要保存起来
    $td = mcrypt_module_open(‘rijndael-256‘, ‘‘, ‘cbc‘, ‘‘); //创建加密环境
    mcrypt_generic_init($td, $key, $iv);
    $decrypted_out_data=mdecrypt_generic($td,  $encrypted_out_data);
    mcrypt_generic_deinit($td);  //释放加密算法资源      
    mcrypt_module_close($td);    //关闭加密环境，释放资源
    
    echo ‘<br>‘;
    echo "密钥是:$key";
    echo ‘<br>‘;
    echo "明文是:$decrypted_out_data";

mcrypt_enc_get_algorithms_name –获取算法具体名称
mcrypt_enc_get_block_size – 获取算法的分组大小
mcrypt_enc_get_iv_size – 获取算法的IV初始化向量大小
mcrypt_enc_get_key_size – 获取算法支持的最大密钥长度
mcrypt_enc_get_modes_name – 获取算法支持的加密模式
mcrypt_enc_get_supported_key_sizes –返回一个数组，里面有算法支持的各种密钥长度 

<?php
    $td = mcrypt_module_open (MCRYPT_BLOWFISH, ‘‘, ‘ecb‘, ‘‘);
    echo mcrypt_enc_get_algorithms_name($td). "\n";
    echo mcrypt_enc_get_block_size($td). "\n";
    echo mcrypt_enc_get_iv_size($td). "\n";
    echo mcrypt_enc_get_key_size($td). "\n";
    echo mcrypt_enc_get_modes_name($td). "\n";
    //结果：Blowfish 8 8 56 ECB

string mcrypt_encrypt ( string cipher, string key, string data, string mode [, string iv])
string mcrypt_decrypt ( string cipher, string key, string data, string mode [, string iv])

<?php
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC);  //获取该算法在OFB模式下的IV向量大小
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); //创建一个初始化IV向量
    $key = "security matrix";   //密钥
    $plaintext = "you should arrive here in eight clock"; //明文
    $ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $plaintext, MCRYPT_MODE_CBC, $iv); //直接执行加密
    echo  "明文是：$plaintext.<br> 密文是: $ciphertext";

    $outtext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key,$ciphertext, MCRYPT_MODE_CBC, $iv); //执行解密
    echo "<br>";
    echo  "解密后的明文是:  $outtext<br>";
    //结果：
    // 明文是：you should arrive here in eight clock.
    //密文是: p 蜉~嵁‘mh!Bl廀‘Es??{ ?e斤舉* YC¬濤溋C海Rc敻J 偰k躕"蟸v勸
    //解密后的明文是: you should arrive here in eight clock

string mcrypt_cbc ( int cipher, string key, string data, int mode [, string iv])
string mcrypt_cbc ( string cipher, string key, string data, int mode [, string iv])

<?php
$key = "security matrix";
$text = "fleshwound is a farmer,deadly wounded ";//明文

$ctext = mcrypt_ecb (MCRYPT_3DES, $key, $text, MCRYPT_ENCRYPT); //加密
$ptext = mcrypt_ecb (MCRYPT_3DES, $key, $ctext, MCRYPT_DECRYPT); //解密

echo "明文：$text <br> 密文：$ctext <br>解密后明文:$ptext"
//结果：
//明文：fleshwound is a farmer,deadly wounded
//密文：皚剢GsXe?+ ?v?3佉:?缟2 拉哣 磀毄+?
//解密后明文:fleshwound is a farmer,deadly wounded