gen_certs.py

#!/usr/bin/env python
import os
import sys

BRO_CERT_TEMPLATE = """#auto generated
redef SSL::root_certs += {
    ["%(subject)s"] = "%(cert)s"
};
"""

def read_file(fn):
    with open(fn) as f:
        return f.read()

def hexify(s):
    return ''.join("\\x" + x.encode('hex').upper() for x in s)

def get_subject(fn):
    #don't really care about the name for now, so just use the filename as the subject
    return os.path.basename(fn)
    
def cert_to_bro_string(fn):
    cert = hexify(read_file(fn))
    subject = get_subject(fn)
    return BRO_CERT_TEMPLATE % dict(subject=subject, cert=cert)

def convert_certs(cert_dir):
    s = ""
    certs = [fn for fn in os.listdir(cert_dir) if fn.endswith(".der")]
    for cert in certs:
        full = os.path.join(cert_dir, cert)
        s += cert_to_bro_string(full)
    return s

if __name__ == "__main__":
    path = sys.argv[1]
    output = sys.argv[2]
    out = convert_certs(path)
    with open(output, 'w') as f:
        f.write(out)