Hello,
I’m pretty new to ruby and this is my first real program I’m writing.
Currently I face an issue with the GPGME gem that I cannot figure out
how to solve: The GPGME::decrypt method does not seem to work as I
expect it, after reading the documentation.
In fact the program seems to hang somewhere during the decryption. My
guess is that something is wrong with my passphrase callback method, but
I cannot figure out how this needs to be done, as the examples for the
gem does not contain a decryption example, only a signing example from
which I have copied the passphrase callback method, but the method does
not seem to work, as the callback method seems to be called with no
arguments.
I have written a test script to work on this problem, it can be found at
the end of the email.
When it hangs after the passphrase callback, after waiting about 10
seconds I’m pressing ^C to interrupt the script. The output of the test
script is as follows:
$ RUBYOPT=rubygems ruby test.rb
pwd:
xxx
encrypting
dumping to file
decrypting
Passphrase callback
^C/var/ruby/1.8/gem_home/gems/gpgme-1.0.8/lib/gpgme.rb:1212:in
decrypt_verify': Interrupt from /var/ruby/1.8/gem_home/gems/gpgme-1.0.8/lib/gpgme.rb:134:in decrypt’
from
/var/ruby/1.8/gem_home/gems/gpgme-1.0.8/lib/gpgme.rb:943:in new' from /var/ruby/1.8/gem_home/gems/gpgme-1.0.8/lib/gpgme.rb:130:in decrypt’
from test.rb:51:in decrypt' from test.rb:43:in run_test’
from test.rb:33:in initialize' from /usr/ruby/1.8/lib/ruby/1.8/singleton.rb:94:in new’
from /usr/ruby/1.8/lib/ruby/1.8/singleton.rb:94:in `instance’
from test.rb:56
$ gpg --decrypt edata
You need a passphrase to unlock the secret key for
user: “xxxx xxxxxxxxxxxx [email protected]”
4096-bit RSA key, ID D2BBECEB, created 2010-01-12 (main key ID ADE8309D)
gpg: encrypted with 4096-bit RSA key, ID D2BBECEB, created 2010-01-12
“xxxx xxxxxxxxxxxx [email protected]”
Dummy test data
Dummy test data
Dummy test data
Dummy test data
Dummy test data
The fact that gpg is able to decrypt the data shows that the encryption
of the data is working perfectly fine, I just cannot figure out how to
do the decryption in GPGME.
A google search for GPGME::decrypt did not help, I could not find
anything besides the documentation of the module.
Script:
#!/usr/bin/env ruby
require ‘singleton’
require ‘gpgme’
class SMGConfig
include Singleton
attr_accessor :gpg_key
attr_accessor :gpg_password
def initialize()
@gpg_key = ‘ADE8309D’
puts “pwd:”
@gpg_password = gets
end
end
#def passfunc(hook, uid_hint, passphrase_info, prev_was_bad, fd)
config = SMGConfig.instance
puts “Passphrase callback”
io = IO.for_fd(fd, ‘w’)
io.puts(config.gpg_password)
io.flush
#end
def passfunc()
SMGConfig.instance.gpg_password
end
class GPG
include Singleton
def initialize()
@config = SMGConfig.instance
run_test()
end
def run_test()
# Run a test if gpg is able to start and encrypt and
decrypt data reliably with the known password
data = “Dummy test data\n” * 5
puts “encrypting”
edata = encrypt(data)
puts “dumping to file”
File.open(‘edata’, ‘w’) { | f | f.write(edata) }
puts “decrypting”
ddata = decrypt(edata)
puts “GPG failed to initialize” if !(data.eql?(ddata))
puts “done run_test”
end
def encrypt(data)
edata = GPGME::encrypt(@config.gpg_key, data)
end
def decrypt(edata)
GPGME::decrypt(edata, { :passphrase_callback =>
passfunc })
end
end
$stdout.sync = true
x = GPG.instance
