如何使Ruby的AES-256-CBC和PHP MCRYPT_RIJNDAEL_128配合默契

Question

我生成要发送的数据从一个Ruby堆栈的PHP堆栈。我使用Ruby端和PHP的“的mcrypt”库OpenSSL的::密码库。当我加密使用“AES-256-CBC”（256位的块大小）的红宝石我需要使用在PHP MCRYPT_RIJNDAEL_128（128位块大小）进行解密。我怀疑Ruby代码被打破，因为cipher.iv_len为16;我相信它应为32：

>> cipher = OpenSSL::Cipher::Cipher.new('aes-128-cbc')
=> #<OpenSSL::Cipher::Cipher:0x3067c5c>
>> cipher.key_len
=> 16
>> cipher.iv_len
=> 16
>> cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
=> #<OpenSSL::Cipher::Cipher:0x306de18>
>> cipher.key_len
=> 32
>> cipher.iv_len
=> 16

因此，这里是我的测试。在Ruby侧，第一I生成密钥和IV：

>> cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
>> cipher.encrypt
>> iv = cipher.random_iv
>> iv64 = [iv].pack("m").strip
=> "vCkaypm5tPmtP3TF7aWrug=="
>> key = cipher.random_key
>> key64 = [key].pack("m").strip
=> "RIvFgoi9xZaHS/0Bp0J9WDRyND6Z7jrd3btiAfcQ8Y0="

然后，我使用这些密钥执行加密：

>> plain_data = "Hi, Don, this is a string."
>> cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
>> cipher.encrypt
>> cipher.key = Base64.decode64(key64)
>> cipher.iv = Base64.decode64(iv64)
>> encrypted_data = cipher.update(plain_data)
>> encrypted_data << cipher.final
>> crypt64 = [encrypted_data].pack("m").strip
=> "5gfC/kJcnAV2fJI0haxnLcdraIKWgtu54UoznVxf8K0="

这里的PHP解密：

$ruby_crypt = "5gfC/kJcnAV2fJI0haxnLcdraIKWgtu54UoznVxf8K0=";
$encrypted_data = base64_decode($ruby_crypt);
$key = base64_decode("RIvFgoi9xZaHS/0Bp0J9WDRyND6Z7jrd3btiAfcQ8Y0=");
$iv = base64_decode("vCkaypm5tPmtP3TF7aWrug==");
$result = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $encrypted_data, MCRYPT_MODE_CBC, $iv);
$unencrypt = rtrim($result, "\x00..\x1F");
print "\nUnencrypted token:\n'$unencrypt'\n";

RESULT:
Unencrypted token:
'Hi, Don, this is a string.'

我宁愿使用较长的块大小。显然我误解的API。帮助

Answer 1

我不知道PHP，而是通过侧栏上的相关问题读书，我看到的转换红宝石AES256解密功能，PHP 。这包括参照此页面，指出在MCRYPT_RIJNDAEL_128 128指的加密块的大小，而不是密钥大小。你会发现，你已经Ruby和PHP之间传递的密钥长度是在两种情况下256位。换句话说，这似乎是预期的行为，并且您已经使用了较大的密钥。

#!/usr/bin/ruby
require 'base64'

puts((Base64.decode64("RIvFgoi9xZaHS/0Bp0J9WDRyND6Z7jrd3btiAfcQ8Y0=").length * 8).to_s)

HTH

Answer 2

我写一个例子别人可能发现上述讨论的说明：

$猫publisher.rb

#!/usr/bin/env ruby

require 'openssl'
require 'base64'

key = '7fc4d85e2e4193b842bb0541de51a497'

cipher = OpenSSL::Cipher::Cipher.new('aes-128-cbc')
cipher.encrypt()
iv = cipher.random_iv

cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
cipher.encrypt()
cipher.key = key
cipher.iv = iv
crypt = cipher.update('This is my text')
crypt << cipher.final()

puts [Base64.encode64(crypt).strip(), Base64.encode64(iv).strip()].join('|')

$猫consumer.php

$key256 = '7fc4d85e2e4193b842bb0541de51a497';

$fd = fopen("php://stdin", "r");
$tokens = '';
while (!feof($fd))
  $tokens .= fread($fd, 1024);
fclose($fd);

$tokens = explode('|', trim($tokens));
$crypt = $tokens[0];
$iv = $tokens[1];

$crypttext = base64_decode($crypt);
$iv = base64_decode($iv);
$decrypted = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key256, $crypttext, MCRYPT_MODE_CBC, $iv);

print $decrypted ."\n";

要测试它，从命令行尝试：

  

$红宝石publisher.rb | PHP consumer.php

     

这是我的文本

Answer 3

我因为PHP是使用密码小于8个字符有很多麻烦。在这种情况下，一个需要添加0，以使其与PHP兼容：

的mcrypt-加密手册页 “键

与该数据将被加密的密钥。如果它不是必需的密钥大小小，则填充为“\ 0”。这是最好不要使用ASCII字符串钥匙。 http://php.net/manual/en/function.mcrypt-encrypt.php 建议使用Mhash函数库来创建从字符串的密钥“。

require 'openssl'
cipher = OpenSSL::Cipher.new('DES-ECB')
cipher.encrypt
key =  'passwrd'[0...7].ljust(8, 0.chr)  #Pad the key smaller than 8 chars
cipher.key = key
encrypted = cipher.update('33')
encrypted << cipher.final
dec = Base64.encode64(encrypted).strip()

Answer 4

让我告诉你一些代码。

PHP代码：

$privateKey = "1234567890123456"; # the size is 16.
$data = "hello";
$iv = "0123456789012345";

$result = mcrypt_encrypt(
  MCRYPT_RIJNDAEL_128, $privateKey, $data, MCRYPT_MODE_CBC, $iv
)

$base64str = base64_encode($result);
$base64str = str_replace("+", "-",  $base64str);
$base64str = str_replace("/","_",  $base64str);

# => f-WffBXnf122NcVBUZ6Rlg==

Ruby代码：

require 'base64'
require 'openssl'

private_key = "1234567890123456"
data = "hello"
iv = "0123456789012345"

cipher = OpenSSL::Cipher::AES.new(128, :CBC) 
cipher.encrypt

cipher.padding = 0 # we must disable padding in ruby.
cipher.key = private_key
cipher.iv = iv
block_size = cipher.block_size

# Add padding by yourself.
data = data + "\0" * (block_size - data.bytesize % block_size)
result = cipher.update(data) + cipher.final

Base64.urlsafe_encode64(result)
# ==> f-WffBXnf122NcVBUZ6Rlg==

正如你可以看到我使用AES-128中红宝石因为private_key的大小为16。 所以，你必须使用AES-256，如果你的private_key的大小为32。

式：size_of_private_key * 8