[feat] initial commmit

Author: grindsa

xca_template_parser.py

@@ -0,0 +1,109 @@
+#!/usr/bin/python3
+""" script to parse an xca certificate template """
+import sys
+from pprint import pprint
+
+def _asn1_stream_parse(asn1_stream=None):
+    """ parse asn_string """
+
+    oid_dic = {
+        "2.5.4.3": "commonName",
+        "2.5.4.4": "surname",
+        "2.5.4.5": "serialNumber",
+        "2.5.4.6": "countryName",
+        "2.5.4.7": "localityName",
+        "2.5.4.8": "stateOrProvinceName",
+        "2.5.4.9": "streetAddress",
+        "2.5.4.10": "organizationName",
+        "2.5.4.11": "organizationalUnitName",
+        "2.5.4.12": "title",
+        "2.5.4.13": "description",
+        "2.5.4.42": "givenName",
+    }
+
+    # cut first 8 bytes which are bogus
+    # asn1_stream = asn1_stream[8:]
+
+    # print(asn1_stream)
+    stream_list = asn1_stream.split(b'\x06\x03\x55')
+
+    # we have to remove the first element from list as it contains junk
+    stream_list.pop(0)
+
+    dn_dic = {}
+    for ele in stream_list:
+        oid = '2.5.{0}.{1}'.format(ele[0], ele[1])
+        if oid in oid_dic:
+            value_len = ele[3]
+            value = ele[4:4+value_len]
+            dn_dic[oid_dic[oid]] = value.decode('utf-8')
+    return dn_dic
+
+
+def _utf_stream_parse(utf_stream=None):
+    """ parse template information from utf_stream into dictitionary """
+
+    template_dic = {}
+
+    if utf_stream:
+        stream_list = utf_stream.split(b'\x00\x00\x00')
+
+        # iterate list and clean up parameter
+        parameter_list = []
+        for idx, ele in enumerate(stream_list):
+            ele = ele.replace(b'\x00', b'')
+            if idx > 0:
+                # strip the first character
+                ele = ele[1:]
+            parameter_list.append(ele.decode('utf-8'))
+
+        if parameter_list:
+            # convert list into a directory
+            template_dic = {item : parameter_list[index+1] for index, item in enumerate(parameter_list) if index % 2 == 0}
+
+    return template_dic
+
+def _stream_split(byte_stream):
+    """ split template in asn1 structure and utf_stream """
+    asn1_stream = None
+    utf_stream = None
+
+    if byte_stream:
+        # search pattern
+        pos = byte_stream.find(b'\x00\x00\x00\x0c') + 4
+
+        # read file again and seek content till position
+        asn1_stream = byte_stream[:pos]
+        utf_stream = byte_stream[pos:]
+
+    return(asn1_stream, utf_stream)
+
+def template_process(byte_string=None):
+    """ process template """
+    (asn1_stream, utf_stream) = _stream_split(byte_string)
+
+    if asn1_stream:
+        dn_dic = _asn1_stream_parse(asn1_stream)
+
+    template_dic = {}
+    if utf_stream:
+        template_dic = _utf_stream_parse(utf_stream)
+        if template_dic:
+            # replace '' with None
+            template_dic = {k: None if not v else v for k, v in template_dic.items()}
+
+    return (dn_dic, template_dic)
+
+if __name__ == '__main__':
+
+    if len(sys.argv) > 1:
+        IN_FILE = sys.argv[1]
+        with open(IN_FILE, 'rb') as in_file:
+            BYTE_STREAM = in_file.read()
+            (DN_DIC, TEMPLATE_DIC) = template_process(BYTE_STREAM)
+            print('\n# DN attributes')
+            pprint(DN_DIC)
+            print('\n# certificate extensions and attributes')
+            pprint(TEMPLATE_DIC)
+    else:
+        print('you need to specify a template file as argument...')