Module: Origami::Encryption::EncryptedStream

Includes:
EncryptedObject
Defined in:
lib/origami/encryption.rb

Overview

Module for encrypted Stream.

Instance Attribute Summary

Attributes included from EncryptedObject

#decrypted

Class Method Summary collapse

Instance Method Summary collapse

Methods included from EncryptedObject

#post_build

Class Method Details

.extended(obj) ⇒ Object 



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# File 'lib/origami/encryption.rb', line 506

def self.extended(obj)
    obj.decrypted = false
end

Instance Method Details

#decrypt! ⇒ Object

Raises:



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# File 'lib/origami/encryption.rb', line 548

def decrypt!
    return self if @decrypted

    if self.filters.first == :Crypt
        params = decode_params.first

        if params.is_a?(Dictionary) and params.Name.is_a?(Name)
            crypt_filter = params.Name.value
        else
            crypt_filter = :Identity
        end

        cipher = self.document.encryption_cipher(crypt_filter)
    else
        cipher = self.document.stream_encryption_cipher
    end
    raise EncryptionError, "Cannot find stream encryption filter" if cipher.nil?

    key = compute_object_key(cipher)

    self.encoded_data = cipher.decrypt(key, @encoded_data)
    @decrypted = true

    self
end

#encrypt! ⇒ Object

Raises:



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# File 'lib/origami/encryption.rb', line 510

def encrypt!
    return self unless @decrypted

    encode!

    if self.filters.first == :Crypt
        params = decode_params.first

        if params.is_a?(Dictionary) and params.Name.is_a?(Name)
            crypt_filter = params.Name.value
        else
            crypt_filter = :Identity
        end

        cipher = self.document.encryption_cipher(crypt_filter)
    else
        cipher = self.document.stream_encryption_cipher
    end
    raise EncryptionError, "Cannot find stream encryption filter" if cipher.nil?

    key = compute_object_key(cipher)

    @encoded_data =
        if cipher == RC4 or cipher == Identity
            cipher.encrypt(key, self.encoded_data)
        else
            iv = Encryption.rand_bytes(AES::BLOCKSIZE)
            cipher.encrypt(key, iv, @encoded_data)
        end

    @decrypted = false

    @encoded_data.freeze
    self.freeze

    self
end