Class: Themis::ScellSealPassphrase

Inherits:
ScellSeal show all
Includes:
ThemisCommon, ThemisImport
Defined in:
lib/rbthemis.rb

Overview

Secure Cell in Seal mode.

Constant Summary

Constants included from ThemisImport

ThemisImport::THEMIS_KEY_EC_PRIVATE, ThemisImport::THEMIS_KEY_EC_PUBLIC, ThemisImport::THEMIS_KEY_INVALID, ThemisImport::THEMIS_KEY_RSA_PRIVATE, ThemisImport::THEMIS_KEY_RSA_PUBLIC

Constants inherited from Scell

Themis::Scell::CONTEXT_IMPRINT_MODE, Themis::Scell::SEAL_MODE, Themis::Scell::TOKEN_PROTECT_MODE

Instance Method Summary collapse

Methods included from ThemisCommon

empty?, string_to_pointer_size

Constructor Details

#initialize(passphrase, encoding: Encoding::UTF_8) ⇒ ScellSealPassphrase

Make a new Secure Cell with given passphrase. The passphrase must not be empty. If the passphrase is not binary it will be encoded in UTF-8 by default, you can use optional “encoding:” argument to use a different encoding.



648
649
650
651
652
653
654
655
656
 
# File 'lib/rbthemis.rb', line 648

def initialize(passphrase, encoding: Encoding::UTF_8)
  if empty? passphrase
    raise ThemisError, "passphrase cannot be empty"
  end
  if passphrase.encoding != Encoding::BINARY
    passphrase = passphrase.encode(encoding)
  end
  @passphrase, @passphrase_length = string_to_pointer_size(passphrase)
end

Instance Method Details

#decrypt(message, context = nil) ⇒ Object

Decrypts message with given context. The context must be the same as the one used during encryption, or be omitted or set to nil if no context were used. Decrypted message is returned as binary data.



696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
 
# File 'lib/rbthemis.rb', line 696

def decrypt(message, context = nil)
  if empty? message
    raise ThemisError, "message cannot be empty"
  end

  message_, message_length_ = string_to_pointer_size(message)
  context_, context_length_ =
    context.nil? ? [nil, 0] : string_to_pointer_size(context)

  decrypted_length = FFI::MemoryPointer.new(:uint)
  res = themis_secure_cell_decrypt_seal_with_passphrase(
    @passphrase, @passphrase_length, context_, context_length_,
    message_, message_length_, nil, decrypted_length)
  if res != BUFFER_TOO_SMALL
    raise ThemisError.new(res), "decrypt failed"
  end

  decrypted_message = FFI::MemoryPointer.new(:char, decrypted_length.read_uint)
  res = themis_secure_cell_decrypt_seal_with_passphrase(
    @passphrase, @passphrase_length, context_, context_length_,
    message_, message_length_, decrypted_message, decrypted_length)
  if res != SUCCESS
    raise ThemisError.new(res), "decrypt failed"
  end

  decrypted_message.get_bytes(0, decrypted_length.read_uint)
end

#encrypt(message, context = nil) ⇒ Object

Encrypts message with given optional context. The context is cryptographically combined with message but is not included into encrypted data, you will need to provide the same context for decryption. Resulting encrypted message includes authentication token. Message must not be empty, but context may be omitted. Both message and context are treated as binary data.



664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
 
# File 'lib/rbthemis.rb', line 664

def encrypt(message, context = nil)
  if empty? message
    raise ThemisError, "message cannot be empty"
  end

  message_, message_length_ = string_to_pointer_size(message)
  context_, context_length_ =
    context.nil? ? [nil, 0] : string_to_pointer_size(context)

  encrypted_length = FFI::MemoryPointer.new(:uint)
  res = themis_secure_cell_encrypt_seal_with_passphrase(
    @passphrase, @passphrase_length, context_, context_length_,
    message_, message_length_, nil, encrypted_length)
  if res != BUFFER_TOO_SMALL
    raise ThemisError.new(res), "encrypt failed"
  end

  encrypted_message = FFI::MemoryPointer.new(:char, encrypted_length.read_uint)
  res = themis_secure_cell_encrypt_seal_with_passphrase(
    @passphrase, @passphrase_length, context_, context_length_,
    message_, message_length_, encrypted_message, encrypted_length)
  if res != SUCCESS
    raise ThemisError.new(res), "encrypt failed"
  end

  encrypted_message.get_bytes(0, encrypted_length.read_uint)
end