Class: IOStreams::Pgp::Reader

Inherits:
Reader
  • Object
show all
Defined in:
lib/io_streams/pgp/reader.rb

Class Attribute Summary collapse

Attributes inherited from Reader

#input_stream

Class Method Summary collapse

Methods inherited from Reader

#initialize, open, stream

Constructor Details

This class inherits a constructor from IOStreams::Reader

Class Attribute Details

.default_passphrase=(value) ⇒ Object

Sets the attribute default_passphrase

Parameters:

  • value —

    the value to set the attribute default_passphrase to.



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# File 'lib/io_streams/pgp/reader.rb', line 8

def default_passphrase=(value)
  @default_passphrase = value
end

Class Method Details

.file(file_name, passphrase: nil, ignore_mdc_error: false) ⇒ Object

Read from a PGP / GPG file , decompressing the contents as it is read.

file_name: [String]

Name of file to read from

passphrase: [String]

Pass phrase for private key to decrypt the file with.
Not required when the file is signed but not encrypted.

ignore_mdc_error: [true|false]

Decrypt files that lack MDC (Modification Detection Code) integrity protection.
Some legacy/enterprise systems (e.g. Workday) still produce such files, which
modern GnuPG refuses to decrypt with `gpg: decryption forced to fail!`.
Only enable this for files from a trusted source: without MDC the decrypted
contents are not protected against tampering.
Default: false



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# File 'lib/io_streams/pgp/reader.rb', line 33

def self.file(file_name, passphrase: nil, ignore_mdc_error: false)
  # Cannot use `passphrase: self.default_passphrase` since it is considered private
  passphrase ||= default_passphrase

  args = []
  # Use --pinentry-mode loopback for all GnuPG versions >= 2.1
  args += ["--pinentry-mode", "loopback"] if IOStreams::Pgp.pgp_version.to_f >= 2.1
  # Use --no-symkey-cache for GnuPG versions >= 2.4 to avoid caching session keys
  args << "--no-symkey-cache" if IOStreams::Pgp.pgp_version.to_f >= 2.4
  args << "--ignore-mdc-error" if ignore_mdc_error
  args += ["--batch", "--no-tty", "--yes", "--decrypt"]
  # Only feed a passphrase when one is supplied; sign-only files need none.
  args += ["--passphrase-fd", "0"] if passphrase
  args << file_name.to_s

  command = IOStreams::Pgp.gpg_command(*args)
  IOStreams.logger&.debug { "IOStreams::Pgp::Reader.open: #{command.shelljoin}" }

  # Read decrypted contents from stdout
  Open3.popen3(*command) do |stdin, stdout, stderr, waith_thr|
    stdin.puts(passphrase) if passphrase
    stdin.close
    result =
      begin
        stdout.binmode
        yield(stdout)
      rescue Errno::EPIPE
        # Ignore broken pipe because gpg terminates early due to an error
        raise(Pgp::Failure, "GPG Failed reading from encrypted file: #{file_name}: #{stderr.read.chomp}")
      end
    raise(Pgp::Failure, "GPG Failed to decrypt file: #{file_name}: #{stderr.read.chomp}") unless waith_thr.value.success?

    result
  end
end