Class: BlockCipherKit::BaseScheme

Inherits:
Object
  • Object
show all
Defined in:
lib/block_cipher_kit/base_scheme.rb

Instance Method Summary collapse

Instance Method Details

#decrypt_range(from_ciphertext_io:, range:) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 14

def decrypt_range(from_ciphertext_io:, range:)
  buf = StringIO.new.binmode
  streaming_decrypt_range(from_ciphertext_io: from_ciphertext_io, range: range, into_plaintext_io: buf)
  buf.string
end

#read_copy_stream_via_cipher(source_io:, cipher:, read_limit: nil, destination_io: nil, finalize_cipher: true, &block_accepting_byte_chunks) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 20

def read_copy_stream_via_cipher(source_io:, cipher:, read_limit: nil, destination_io: nil, finalize_cipher: true, &block_accepting_byte_chunks)
  writable = BlockCipherKit::BlockWritable.new(destination_io, &block_accepting_byte_chunks)
  cipher_io = BlockCipherKit::CipherIO.new(writable, cipher)
  IO.copy_stream(source_io, cipher_io, read_limit)
  # Some cases require us to skip authentication which gets performed in cipher.final
  # - like decrypting a few blocks of CBC without decrypting the last block. This skips cipher
  # authentication but is required for random access.
  writable.write(cipher.final) if finalize_cipher
end

#streaming_decrypt(from_ciphertext_io:, into_plaintext_io: nil, &blk) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 2

def streaming_decrypt(from_ciphertext_io:, into_plaintext_io: nil, &blk)
  raise "Unimplemented"
end

#streaming_decrypt_range(from_ciphertext_io:, range:, into_plaintext_io: nil, &blk) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 10

def streaming_decrypt_range(from_ciphertext_io:, range:, into_plaintext_io: nil, &blk)
  raise "Unimplemented"
end

#streaming_encrypt(into_ciphertext_io:, from_plaintext_io: nil, &blk) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 6

def streaming_encrypt(into_ciphertext_io:, from_plaintext_io: nil, &blk)
  raise "Unimplemented"
end

#write_copy_stream_via_cipher(cipher:, destination_io:, source_io: nil, read_limit: nil, &block_accepting_writable_io) ⇒ Object 



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# File 'lib/block_cipher_kit/base_scheme.rb', line 30

def write_copy_stream_via_cipher(cipher:, destination_io:, source_io: nil, read_limit: nil, &block_accepting_writable_io)
  w = BlockCipherKit::CipherIO.new(destination_io, cipher)
  if !source_io && block_accepting_writable_io && !read_limit
    block_accepting_writable_io.call(w)
  elsif !source_io && block_accepting_writable_io && read_limit
    raise "write_copy_stream_via_cipher cannot enforce read_limit when writing via a block"
  elsif source_io && !block_accepting_writable_io
    IO.copy_stream(source_io, w, read_limit)
  else
    raise ArgumentError, "Either source_io: or a block accepting a writable IO must be provided"
  end
  destination_io.write(cipher.final)
end