轨道加密/解密

Question

我需要在我的 Rails 应用程序中进行加密和解密。我尝试使用 ezcrypto，但每当我解密时都会出现此错误。

OpenSSL::Cipher::CipherError in ProfilesController#show

wrong final block length

需要更改哪些内容才能阻止此错误。我尝试使用这样的 openssl 的另一种实现（从我的模型中调用的方法）

def encrypt_attr(unencrypted)
    c = OpenSSL::Cipher.new("aes-256-cbc")
    c.encrypt
    c.key = Digest::SHA1.hexdigest('pass')
    e = c.update(unencrypted)
    e << c.final
    return e
end

def decrypt_attr(encrypted_attr)
  if encrypted_attr != ""
    c = OpenSSL::Cipher::Cipher.new("aes-256-cbc")
    c.decrypt
    c.key = Digest::SHA1.hexdigest('pass')
    d = c.update(encrypted_attr)
    d << c.final
    return d
  end
end

它在解密时抛出完全相同的错误。我应该如何进行加密和解密而不得到这个openssl错误。

Answer 1

require 'openssl'
require 'base64'

class AesEncryptDecrypt

  KEY = "EncryptDecryptGurudathBN"
  ALGORITHM = 'AES-128-ECB'

  def self.encryption(msg)
    begin
      cipher = OpenSSL::Cipher.new(ALGORITHM)
      cipher.encrypt()
      cipher.key = KEY
      crypt = cipher.update(msg) + cipher.final()
      crypt_string = (Base64.encode64(crypt))
      return crypt_string
    rescue Exception => exc
      puts ("Message for the encryption log file for message #{msg} = #{exc.message}")
    end
  end

  def self.decryption(msg)
    begin
      cipher = OpenSSL::Cipher.new(ALGORITHM)
      cipher.decrypt()
      cipher.key = KEY
      tempkey = Base64.decode64(msg)
      crypt = cipher.update(tempkey)
      crypt << cipher.final()
      return crypt
    rescue Exception => exc
      puts ("Message for the decryption log file for message #{msg} = #{exc.message}")
    end
  end
end

加密

irb(main):007:0> AesEncryptDecrypt.encryption('gurudath')
=> "rUPKObydUJd9cY9agm3Glw==\n"

解密

irb(main):008:0> AesEncryptDecrypt.decryption('rUPKObydUJd9cY9agm3Glw==')
=> "gurudath"

Answer 2

我知道 Ruby 的 openssl 包的文档非常少。但是，如果您想使用 cipher-block chaining，这里有一段简短的 sn-p 代码，概述了如何使用 AES-256-CBC 密码：

require 'openssl'

# your data
raw  = 'the data to be encrypted goes here'
pwd  = 'secret'
salt = OpenSSL::Random.random_bytes(8)

# prepare cipher for encryption
e = OpenSSL::Cipher.new('AES-256-CBC')
e.encrypt
# next, generate a PKCS5-based string for your key + initialization vector 
key_iv = OpenSSL::PKCS5.pbkdf2_hmac_sha1(pwd, salt, 2000, e.key_len+e.iv_len)
key = key_iv[0, e.key_len]
iv  = key_iv[e.key_len, e.iv_len]

# now set the key and iv for the encrypting cipher
e.key = key
e.iv  = iv

# encrypt the data!
encrypted = '' << e.update(raw) << e.final
p encrypted

# and now we prepare to decrypt
d = OpenSSL::Cipher.new('AES-256-CBC')
d.decrypt
# now set the key and iv for the decrypting cipher
# this assumes that the password, salt, and iv are known,
# so then you would be able to generate the key as per above
d.key = key
d.iv  = iv

# decrypt the data!
decrypted = '' << d.update(encrypted) << d.final
p decrypted

这个 sn-p 几乎一字不差地取自 Japanese (original?) version of the Ruby standard library documentation on openssl。但是，它确实为您和您的应用程序设计提出了一些问题：

1. 您需要保存salt 值。这与密码一起用于生成密钥（您不需要保存密钥）。
2. 您需要保存iv 初始化向量。这用于启动密码块链中的第一个块。无需加密此值，但应为您加密的每条消息生成此值。

祝你好运！

Answer 3

我遇到了和你一样的问题，我就是这样解决的：

1. 您的数据库列必须是：t.column :data, :binary, :limit => 10.megabyte。
2. 使用准确的代码this blog post。
3. 选择 AES-256-ECB
4. 将 ivs 设为 nil
5. 选择一个长键