sign.py

It is an experimental testing for python M2Crypto module. M2Crypto is not well document. User may no

#!/usr/bin/env python

from M2Crypto import RSA, EVP, Rand
import time,sys
#import sha

def sign(keyfn, msgfn, outfn):
    print 'sign (%s, %s, %s)' % (keyfn,msgfn,outfn)
    key = RSA.load_key(keyfn)
    ft= open(msgfn,'rb')
    text = ft.read()
    ft.close()
    shax = EVP.MessageDigest('sha1')
    shax.update(text)
    dig = shax.digest()
    #dig = sha.new(text).digest()
    fd = open(msgfn,'rb')
    msg = fd.read()
    #padding = RSA.pkcs1_padding
    padding = RSA.pkcs1_oaep_padding
    ptxt = key.sign(dig)
    fd.close()
    fo = open(outfn, 'wb')
    fo.write(ptxt)
    fo.close()
    print ptxt
    print 'done'    

if __name__=='__main__':
    from optparse import OptionParser
    parser = OptionParser(usage='sign [-k] [-o] msg', version='sign 1.0')
    parser.add_option('-k','--key',dest='key', help='private key',default='svpvk.pem')
    parser.add_option('-o','--out',dest='output',help='output file',default='sign.dat')
    (options,args) = parser.parse_args()
    keyfn = options.key
    outfn = options.output
    msgfn = args[0]
    sign(keyfn,msgfn,outfn)