CSR parser from freeipa, modified by Dan and Seth - GPLv2, depends on libnss and python-nss

client-webserver/pkcs10.py

@@ -0,0 +1,91 @@
+# Authors:
+#   Rob Crittenden <rcritten@redhat.com>
+#
+# Copyright (C) 2010  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; version 2 only
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+import os
+import sys
+import base64
+import nss.nss as nss
+
+def get_subjectaltname(request):
+    """
+    Given a CSR return the subjectaltname value, if any.
+
+    The return value is a tuple of strings or None
+    """
+    for extension in request.extensions:
+        if extension.oid_tag  == nss.SEC_OID_X509_SUBJECT_ALT_NAME:
+            return nss.x509_alt_name(extension.value)
+    return None
+
+def get_subject(request):
+    """
+    Given a CSR return the subject value.
+
+    This returns an nss.DN object.
+    """
+    return request.subject
+
+def strip_header(csr):
+    """
+    Remove the header and footer from a CSR.
+    """
+    headerlen = 40
+    s = csr.find("-----BEGIN NEW CERTIFICATE REQUEST-----")
+    if s == -1:
+        headerlen = 36
+        s = csr.find("-----BEGIN CERTIFICATE REQUEST-----")
+    if s >= 0:
+        e = csr.find("-----END")
+        csr = csr[s+headerlen:e]
+
+    return csr
+
+def load_certificate_request(csr):
+    """
+    Given a base64-encoded certificate request, with or without the
+    header/footer, return a request object.
+    """
+    csr = strip_header(csr)
+
+    substrate = base64.b64decode(csr)
+
+    # A fail-safe so we can always read a CSR. python-nss/NSS will segfault
+    # otherwise
+    if not nss.nss_is_initialized():
+        nss.nss_init_nodb()
+
+    return nss.CertificateRequest(substrate)
+
+if __name__ == '__main__':
+    nss.nss_init_nodb()
+
+    # Read PEM request from stdin and print out its components
+
+    csrlines = sys.stdin.readlines()
+    # csrlines = fp.readlines()
+    # fp.close()
+    csr = ''.join(csrlines)
+
+    csr = load_certificate_request(csr)
+
+    # print csr
+
+    sans = get_subjectaltname(csr)
+    if not sans: sans = [] 
+    print [x.split("=")[1] for x in [f for f in str(get_subject(csr)).split(",") if f[:3] == "CN="]] + list(sans)