class Net::SSH::Authentication::ED25519::OpenSSHPrivateKeyLoader

# File lib/net/ssh/authentication/ed25519.rb, line 43
def self.read(datafull, password)
  raise ArgumentError.new("Expected #{MBEGIN} at start of private key") unless datafull.start_with?(MBEGIN)
  raise ArgumentError.new("Expected #{MEND} at end of private key") unless datafull.end_with?(MEND)
  datab64 = datafull[MBEGIN.size...-MEND.size]
  data = Base64.decode64(datab64)
  raise ArgumentError.new("Expected #{MAGIC} at start of decoded private key") unless data.start_with?(MAGIC)
  buffer = Net::SSH::Buffer.new(data[MAGIC.size + 1..-1])

  ciphername = buffer.read_string
  raise ArgumentError.new("#{ciphername} in private key is not supported") unless
    CipherFactory.supported?(ciphername)

  kdfname = buffer.read_string
  raise ArgumentError.new("Expected #{kdfname} to be or none or bcrypt") unless %w[none bcrypt].include?(kdfname)

  kdfopts = Net::SSH::Buffer.new(buffer.read_string)
  num_keys = buffer.read_long
  raise ArgumentError.new("Only 1 key is supported in ssh keys #{num_keys} was in private key") unless num_keys == 1
  _pubkey = buffer.read_string

  len = buffer.read_long

  keylen, blocksize, ivlen = CipherFactory.get_lengths(ciphername, iv_len: true)
  raise ArgumentError.new("Private key len:#{len} is not a multiple of #{blocksize}") if
    ((len < blocksize) || ((blocksize > 0) && (len % blocksize) != 0))

  if kdfname == 'bcrypt'
    salt = kdfopts.read_string
    rounds = kdfopts.read_long

    raise "BCryptPbkdf is not implemented for jruby" if RUBY_PLATFORM == "java"
    key = BCryptPbkdf::key(password, salt, keylen + ivlen, rounds)
  else
    key = '\x00' * (keylen + ivlen)
  end

  cipher = CipherFactory.get(ciphername, key: key[0...keylen], iv:key[keylen...keylen + ivlen], decrypt: true)

  decoded = cipher.update(buffer.remainder_as_buffer.to_s)
  decoded << cipher.final

  decoded = Net::SSH::Buffer.new(decoded)
  check1 = decoded.read_long
  check2 = decoded.read_long

  raise DecryptError.new("Decrypt failed on private key", encrypted_key: kdfname == 'bcrypt') if (check1 != check2)

  type_name = decoded.read_string
  case type_name
  when "ssh-ed25519"
    PrivKey.new(decoded)
  else
    decoded.read_private_keyblob(type_name)
  end
end