#!/usr/bin/env python # # Electrum - lightweight Bitcoin client # Copyright (C) 2014 Thomas Voegtlin # # 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, either version 3 of the License, or # (at your option) any later version. # # 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, see . from datetime import datetime import sys import tlslite import util from util import profiler, print_error from asn1tinydecoder import asn1_node_root, asn1_get_all, asn1_get_value, \ asn1_get_value_of_type, asn1_node_next, asn1_node_first_child, \ asn1_read_length, asn1_node_is_child_of, \ bytestr_to_int, bitstr_to_bytestr # workaround https://github.com/trevp/tlslite/issues/15 tlslite.utils.cryptomath.pycryptoLoaded = False # algo OIDs ALGO_RSA_SHA1 = '1.2.840.113549.1.1.5' ALGO_RSA_SHA256 = '1.2.840.113549.1.1.11' ALGO_RSA_SHA384 = '1.2.840.113549.1.1.12' ALGO_RSA_SHA512 = '1.2.840.113549.1.1.13' # prefixes, see http://stackoverflow.com/questions/3713774/c-sharp-how-to-calculate-asn-1-der-encoding-of-a-particular-hash-algorithm PREFIX_RSA_SHA256 = bytearray([0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20]) PREFIX_RSA_SHA384 = bytearray([0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30]) PREFIX_RSA_SHA512 = bytearray([0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,0x40]) class CertificateError(Exception): pass def decode_str(data): encoding = 'utf-16-be' if isinstance(data, BMPString) else 'utf-8' return bytes(data).decode(encoding) def decode_OID(s): s = map(ord, s) r = [] r.append(s[0] / 40) r.append(s[0] % 40) k = 0 for i in s[1:]: if i<128: r.append(i + 128*k) k = 0 else: k = (i - 128) + 128*k return '.'.join(map(str,r)) class X509(tlslite.X509): """Child class of tlslite.X509 that uses pyasn1 to parse cert information. Note: pyasn1 is a lot slower than tlslite, so we should try to do everything in tlslite. """ def get_children(self, der, i): nodes = [] ii = asn1_node_first_child(der,i) while True: nodes.append(ii) ii = asn1_node_next(der,ii) if ii[0] > i[2]: break return nodes def get_dict(self, der, i): p = {} for ii in self.get_children(der, i): for iii in self.get_children(der, ii): iiii = asn1_node_first_child(der, iii) oid = decode_OID(asn1_get_value_of_type(der, iiii, 'OBJECT IDENTIFIER')) iiii = asn1_node_next(der, iiii) value = asn1_get_value(der, iiii) p[oid] = value return p def parseBinary(self, b): # call tlslite method first tlslite.X509.parseBinary(self, b) der = str(b) root = asn1_node_root(der) cert = asn1_node_first_child(der, root) # data for signature self.data = asn1_get_all(der, cert) # optional version field if asn1_get_value(der, cert)[0] == chr(0xa0): version = asn1_node_first_child(der, cert) serial_number = asn1_node_next(der, version) else: serial_number = asn1_node_first_child(der, cert) self.serial_number = bytestr_to_int(asn1_get_value_of_type(der, serial_number, 'INTEGER')) # signature algorithm sig_algo = asn1_node_next(der, serial_number) ii = asn1_node_first_child(der, sig_algo) self.sig_algo = decode_OID(asn1_get_value_of_type(der, ii, 'OBJECT IDENTIFIER')) # issuer issuer = asn1_node_next(der, sig_algo) self.issuer = self.get_dict(der, issuer) # validity validity = asn1_node_next(der, issuer) ii = asn1_node_first_child(der, validity) self.notBefore = asn1_get_value_of_type(der, ii, 'UTCTime') ii = asn1_node_next(der,ii) self.notAfter = asn1_get_value_of_type(der, ii, 'UTCTime') # subject subject = asn1_node_next(der, validity) self.subject = self.get_dict(der, subject) subject_pki = asn1_node_next(der, subject) # optional fields: issuer_uid, subject_uid, extensions i = subject_pki self.CA = False while True: i = asn1_node_next(der, i) if i[0] > cert[2]: break for ii in self.get_children(der, i): for iii in self.get_children(der, ii): iiii = asn1_node_first_child(der, iii) oid = decode_OID(asn1_get_value_of_type(der, iiii, 'OBJECT IDENTIFIER')) iiii = asn1_node_next(der, iiii) value = asn1_get_value(der, iiii) if oid == '2.5.29.19': # basic constraints self.CA = value else: pass # cert signature cert_sig_algo = asn1_node_next(der, cert) ii = asn1_node_first_child(der, cert_sig_algo) self.cert_sig_algo = decode_OID(asn1_get_value_of_type(der, ii, 'OBJECT IDENTIFIER')) cert_sig = asn1_node_next(der, cert_sig_algo) self.signature = asn1_get_value(der, cert_sig)[1:] def get_common_name(self): return self.subject.get('2.5.4.3', 'unknown') def get_issuer(self): return self.issuer.get('2.5.4.3', 'unknown') def get_signature(self): return self.cert_sig_algo, self.signature, self.data def check_ca(self): return self.CA def check_date(self): import time now = time.time() TIMESTAMP_FMT = '%y%m%d%H%M%SZ' not_before = time.mktime(time.strptime(self.notBefore, TIMESTAMP_FMT)) not_after = time.mktime(time.strptime(self.notAfter, TIMESTAMP_FMT)) if not_before > now: raise CertificateError('Certificate has not entered its valid date range.') if not_after <= now: raise CertificateError('Certificate has expired.') class X509CertChain(tlslite.X509CertChain): pass @profiler def load_certificates(ca_path): ca_list = {} with open(ca_path, 'r') as f: s = f.read() bList = tlslite.utils.pem.dePemList(s, "CERTIFICATE") for b in bList: x = X509() try: x.parseBinary(b) x.check_date() except Exception as e: util.print_error("cert error:", e) continue ca_list[x.get_common_name()] = x return ca_list