a ruby interface to GnuPG Made Easy (GPGME).
Ruby C
Latest commit 2e2c57a Nov 25, 2016 @ueno Update tarballs



This README is better viewed through the YARD formatted documentation: rdoc.info/github/ueno/ruby-gpgme/frames for latest github version, or rdoc.info/gems/gpgme for latest gem release.

Status Coverage


  • Ruby 1.8 or later

  • GPGME 1.1.2 or later

  • gpg-agent (optional, but recommended)


$ gem install gpgme


GPGME provides three levels of API. The highest level API is as simple as it gets, the mid level API provides more functionality but might be less user-friendly, and the lowest level API is close to the C interface of GPGME.

The highest level API

For example, to create a cleartext signature of the plaintext from stdin and write the result to stdout can be written as follows.

crypto = GPGME::Crypto.new
crypto.clearsign $stdin, :output => $stdout

The mid level API

The same example can be rewritten in the mid level API as follows.

plain = GPGME::Data.new($stdin)
sig   = GPGME::Data.new($stdout)
GPGME::Ctx.new do |ctx|
  ctx.sign(plain, sig, GPGME::SIG_MODE_CLEAR)

The lowest level API

The same example can be rewritten in the lowest level API as follows.

ret = []
ctx = ret.shift
GPGME::gpgme_data_new_from_fd(ret, 0)
plain = ret.shift
GPGME::gpgme_data_new_from_fd(ret, 1)
sig = ret.shift
GPGME::gpgme_op_sign(ctx, plain, sig, GPGME::SIG_MODE_CLEAR)

As you see, it's much harder to write a program in this API than the highest level API. However, if you are already familiar with the C interface of GPGME and want to control detailed behavior of GPGME, it might be useful.


All the high level methods attack the mid level {GPGME::Ctx} API. It is recommended to read through the #{GPGME::Ctx.new} methods for common options.

Also, most of the input/output is done via {GPGME::Data} objects that create a common interface for reading/writing to normal strings, or other common objects like files. Read the {GPGME::Data} documentation to understand how it works. Every time the lib needs a {GPGME::Data} object, it will be automatically converted to it.


The {GPGME::Crypto} class has the high level convenience methods to encrypt, decrypt, sign and verify signatures. Here are some examples, but it is recommended to read through the {GPGME::Crypto} class to see all the options.

  • Document encryption via {GPGME::Crypto#encrypt}:

crypto = GPGME::Crypto.new
crypto.encrypt "Hello world!", :recipients => "someone@example.com"
  • Symmetric encryption:

crypto = GPGME::Crypto.new :password => "gpgme"
crypto.encrypt "Hello world!", :symmetric => true
  • Document decryption via {GPGME::Crypto#decrypt} (including signature verification):

crypto.decrypt File.open("text.gpg")
  • Document signing via {GPGME::Crypto#sign}. Also the clearsigning and detached signing.

crypto.sign "I hereby proclaim Github the beneficiary of all my money when I die"
  • Sign verification via {GPGME::Crypto#verify}

sign = crypto.sign "Some text"
data = crypto.verify(sign) { |signature| signature.valid? }


The {GPGME::Key} object represents a key, and has the high level related methods to work with them and find them, export, import, deletetion and creation.

  • Key listing

GPGME::Key.find(:secret, "someone@example.com")
# => Returns an array with all the secret keys available in the keychain.
#    that match "someone@example.com"
  • Key exporting

# => Returns a {GPGME::Data} object with the exported key.

key = GPGME::Key.find(:secret, "someone@example.com").first
# => Returns a {GPGME::Data} object with the exported key.
  • Key importing

  • TODO: Key generation


Provides three convenience methods to obtain information about the gpg engine one is currently using. For example:

  • Getting current information

     # => #<GPGME::EngineInfo:0x00000100d4fbd8
  • Changing home directory to work with different settings:

GPGME::Engine.home_dir = '/tmp'


To run the local test suite you need bundler and gpg:

rake compile   # simple rake task to compile the extension
rake           # runs the test suite


The library itself is licensed under LGPLv2.1+. See the file COPYING.LESSER and each file for copyright and warranty information.