import gpgme
import sys
import StringIO

sig = open(sys.argv[1], 'r')
if len(sys.argv) > 2:
    signed_text = open(sys.argv[2], 'r')
    plaintext = None
else:
    signed_text = None
    plaintext = StringIO.StringIO()

ctx = gpgme.Context()

try:
    sigs = ctx.verify(sig, signed_text, plaintext)
except gpgme.GpgmeError, e:
    print 'INVALID SIGNATURE - AWOOOOOOOOOGA'
else:
    thissig = sigs[0]
    if thissig:
        print thissig.fpr
        if thissig.validity in (gpgme.VALIDITY_FULL,
                            gpgme.VALIDITY_MARGINAL,
                            gpgme.VALIDITY_ULTIMATE):
            print 'trusted signature'
        else:
            print 'unsigned signature'