Module: ICAPrb::Filter::Steganography::Cryptography

Defined in:
lib/icaprb/filter/steganography.rb

Overview

contains the code to encrypt the watermarks

Constant Summary collapse

Cipher_To_Use =

Cipher to use

'CAMELLIA-256-CBC'

Class Method Summary collapse

Class Method Details

.decrypt(data, key) ⇒ Object

decrypt data using the the algorithm given in Cipher_To_Use using OpenSSL parameters:

data

data to decrypt

key

the key to use when decrypting data - when the default cipher is used, this must be 32 bytes

returns the decrypted string raises an error if the decryption is not successful



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# File 'lib/icaprb/filter/steganography.rb', line 40

def decrypt(data, key)
  cipher = OpenSSL::Cipher.new(Cipher_To_Use)
  cipher.decrypt
  iv = data[0..15]
  encrypted_data = data[16...(data.length)]
  cipher.iv = iv
  cipher.key = key
  cipher.update(encrypted_data) + cipher.final
end

.encrypt(data, key) ⇒ Object

encrypt data using the the algorithm given in Cipher_To_Use using OpenSSL parameters:

data

data to encrypt

key

the key to use when encrypting data - when the default cipher is used, this must be 32 bytes

returns the cipher string



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# File 'lib/icaprb/filter/steganography.rb', line 24

def encrypt(data, key)
  cipher = OpenSSL::Cipher.new(Cipher_To_Use)
    cipher.encrypt
    iv = cipher.random_iv
    cipher.key = key
    encrypted_data = cipher.update(data) + cipher.final
    iv + encrypted_data
end