| #!/usr/bin/env python | |
| # | |
| # fetch the certificate that the server(s) are providing in PEM form | |
| # | |
| # args are HOST:PORT [, HOST:PORT...] | |
| # | |
| # By Bill Janssen. | |
| import sys | |
| def fetch_server_certificate (host, port): | |
| import re, tempfile, os, ssl | |
| def subproc(cmd): | |
| from subprocess import Popen, PIPE, STDOUT | |
| proc = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True) | |
| status = proc.wait() | |
| output = proc.stdout.read() | |
| return status, output | |
| def strip_to_x509_cert(certfile_contents, outfile=None): | |
| m = re.search(r"^([-]+BEGIN CERTIFICATE[-]+[\r]*\n" | |
| r".*[\r]*^[-]+END CERTIFICATE[-]+)$", | |
| certfile_contents, re.MULTILINE | re.DOTALL) | |
| if not m: | |
| return None | |
| else: | |
| tn = tempfile.mktemp() | |
| fp = open(tn, "w") | |
| fp.write(m.group(1) + "\n") | |
| fp.close() | |
| try: | |
| tn2 = (outfile or tempfile.mktemp()) | |
| status, output = subproc(r'openssl x509 -in "%s" -out "%s"' % | |
| (tn, tn2)) | |
| if status != 0: | |
| raise OperationError(status, tsig, output) | |
| fp = open(tn2, 'rb') | |
| data = fp.read() | |
| fp.close() | |
| os.unlink(tn2) | |
| return data | |
| finally: | |
| os.unlink(tn) | |
| if sys.platform.startswith("win"): | |
| tfile = tempfile.mktemp() | |
| fp = open(tfile, "w") | |
| fp.write("quit\n") | |
| fp.close() | |
| try: | |
| status, output = subproc( | |
| 'openssl s_client -connect "%s:%s" -showcerts < "%s"' % | |
| (host, port, tfile)) | |
| finally: | |
| os.unlink(tfile) | |
| else: | |
| status, output = subproc( | |
| 'openssl s_client -connect "%s:%s" -showcerts < /dev/null' % | |
| (host, port)) | |
| if status != 0: | |
| raise OSError(status) | |
| certtext = strip_to_x509_cert(output) | |
| if not certtext: | |
| raise ValueError("Invalid response received from server at %s:%s" % | |
| (host, port)) | |
| return certtext | |
| if __name__ == "__main__": | |
| if len(sys.argv) < 2: | |
| sys.stderr.write( | |
| "Usage: %s HOSTNAME:PORTNUMBER [, HOSTNAME:PORTNUMBER...]\n" % | |
| sys.argv[0]) | |
| sys.exit(1) | |
| for arg in sys.argv[1:]: | |
| host, port = arg.split(":") | |
| sys.stdout.write(fetch_server_certificate(host, int(port))) | |
| sys.exit(0) |