Encryption / decryption

Question

I need to do encryption and decryption in my rails application. I try to use ezcrypto, but whenever I do the decryption, I get this error.

OpenSSL::Cipher::CipherError in ProfilesController#show

wrong final block length

What needs to be changed to stop this error. I tried using another openssl implementation like this (methods that will be called from my model)

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

It gives the same decryption error. How can I do encryption and decryption, and not get this openssl error.

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

Encryption

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

decryption

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

Answer 2

, Ruby openssl. , , , , AES-256-CBC:

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

(?) Ruby openssl. , :

• salt. ( ).
• iv. . , .

!

Answer 3

, , :

• : t.column: data,: binary,: limit = > 10.megabyte.
• .
• AES-256-ECB
• ivs nil