python openssl 读取 crl 吊销 证书

import OpenSSL

fp = open('/Users/heyong/Downloads/DZCACrl20130502.crl','r')

crl = "".join(fp.readlines())

crl_object = OpenSSL.crypto.load_crl(OpenSSL.crypto.FILETYPE_ASN1, crl)

revoked_objects = crl_object.get_revoked()

for rvk in revoked_objects:

    print rvk.get_serial()