Filename: //lib/python3///dist-packages//pysimplesoap/xmlsec.py

#!/usr/bin/python # -*- coding: utf-8 -*- # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU Lesser General Public License as published by the # Free Software Foundation; either version 3, 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. """Pythonic XML Security Library implementation""" from __future__ import print_function import base64 import hashlib import os from cStringIO import StringIO from M2Crypto import BIO, EVP, RSA, X509, m2 # if lxml is not installed, use c14n.py native implementation try: import lxml.etree except ImportError: lxml = None # Features: # * Uses M2Crypto and lxml (libxml2) but it is independent from libxmlsec1 # * Sign, Verify, Encrypt & Decrypt XML documents # Enveloping templates ("by reference": signature is parent): SIGN_REF_TMPL = """ <SignedInfo xmlns="http://www.w3.org/2000/09/xmldsig#"> <CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /> <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" /> <Reference URI="%(ref_uri)s"> <Transforms> <Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /> </Transforms> <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" /> <DigestValue>%(digest_value)s</DigestValue> </Reference> </SignedInfo> """ SIGNED_TMPL = """ <?xml version="1.0" encoding="UTF-8"?> <Signature xmlns="http://www.w3.org/2000/09/xmldsig#"> %(signed_info)s <SignatureValue>%(signature_value)s</SignatureValue> %(key_info)s %(ref_xml)s </Signature> """ # Enveloped templates (signature is child, the reference is the root object): SIGN_ENV_TMPL = """ <SignedInfo xmlns="http://www.w3.org/2000/09/xmldsig#"> <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/> <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/> <Reference URI=""> <Transforms> <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/> <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/> </Transforms> <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/> <DigestValue>%(digest_value)s</DigestValue> </Reference> </SignedInfo> """ SIGNATURE_TMPL = """<Signature xmlns="http://www.w3.org/2000/09/xmldsig#"> %(signed_info)s <SignatureValue>%(signature_value)s</SignatureValue> %(key_info)s </Signature>""" KEY_INFO_RSA_TMPL = """ <KeyInfo> <KeyValue> <RSAKeyValue> <Modulus>%(modulus)s</Modulus> <Exponent>%(exponent)s</Exponent> </RSAKeyValue> </KeyValue> </KeyInfo> """ KEY_INFO_X509_TMPL = """ <KeyInfo> <X509Data> <X509IssuerSerial> <X509IssuerName>%(issuer_name)s</X509IssuerName> <X509SerialNumber>%(serial_number)s</X509SerialNumber> </X509IssuerSerial> </X509Data> </KeyInfo> """ def canonicalize(xml, c14n_exc=True): "Return the canonical (c14n) form of the xml document for hashing" # UTF8, normalization of line feeds/spaces, quoting, attribute ordering... output = StringIO() if lxml is not None: # use faster libxml2 / lxml canonicalization function if available et = lxml.etree.parse(StringIO(xml)) et.write_c14n(output, exclusive=c14n_exc) else: # use pure-python implementation: c14n.py (avoid recursive import) from .simplexml import SimpleXMLElement SimpleXMLElement(xml).write_c14n(output, exclusive=c14n_exc) return output.getvalue() def sha1_hash_digest(payload): "Create a SHA1 hash and return the base64 string" return base64.b64encode(hashlib.sha1(payload).digest()) def rsa_sign(xml, ref_uri, private_key, password=None, cert=None, c14n_exc=True, sign_template=SIGN_REF_TMPL, key_info_template=KEY_INFO_RSA_TMPL): "Sign an XML document usign RSA (templates: enveloped -ref- or enveloping)" # normalize the referenced xml (to compute the SHA1 hash) ref_xml = canonicalize(xml, c14n_exc) # create the signed xml normalized (with the referenced uri and hash value) signed_info = sign_template % {'ref_uri': ref_uri, 'digest_value': sha1_hash_digest(ref_xml)} signed_info = canonicalize(signed_info, c14n_exc) # Sign the SHA1 digest of the signed xml using RSA cipher pkey = RSA.load_key(private_key, lambda *args, **kwargs: password) signature = pkey.sign(hashlib.sha1(signed_info).digest()) # build the mapping (placeholders) to create the final xml signed message return { 'ref_xml': ref_xml, 'ref_uri': ref_uri, 'signed_info': signed_info, 'signature_value': base64.b64encode(signature), 'key_info': key_info(pkey, cert, key_info_template), } def rsa_verify(xml, signature, key, c14n_exc=True): "Verify a XML document signature usign RSA-SHA1, return True if valid" # load the public key (from buffer or filename) if key.startswith("-----BEGIN PUBLIC KEY-----"): bio = BIO.MemoryBuffer(key) rsa = RSA.load_pub_key_bio(bio) else: rsa = RSA.load_pub_key(certificate) # create the digital envelope pubkey = EVP.PKey() pubkey.assign_rsa(rsa) # do the cryptographic validation (using the default sha1 hash digest) pubkey.reset_context(md='sha1') pubkey.verify_init() # normalize and feed the signed xml to be verified pubkey.verify_update(canonicalize(xml, c14n_exc)) ret = pubkey.verify_final(base64.b64decode(signature)) return ret == 1 def key_info(pkey, cert, key_info_template): "Convert private key (PEM) to XML Signature format (RSAKeyValue/X509Data)" exponent = base64.b64encode(pkey.e[4:]) modulus = m2.bn_to_hex(m2.mpi_to_bn(pkey.n)).decode("hex").encode("base64") x509 = x509_parse_cert(cert) if cert else None return key_info_template % { 'modulus': modulus, 'exponent': exponent, 'issuer_name': x509.get_issuer().as_text() if x509 else "", 'serial_number': x509.get_serial_number() if x509 else "", } # Miscellaneous certificate utility functions: def x509_parse_cert(cert, binary=False): "Create a X509 certificate from binary DER, plain text PEM or filename" if binary: bio = BIO.MemoryBuffer(cert) x509 = X509.load_cert_bio(bio, X509.FORMAT_DER) elif cert.startswith("-----BEGIN CERTIFICATE-----"): bio = BIO.MemoryBuffer(cert) x509 = X509.load_cert_bio(bio, X509.FORMAT_PEM) else: x509 = X509.load_cert(cert, 1) return x509 def x509_extract_rsa_public_key(cert, binary=False): "Return the public key (PEM format) from a X509 certificate" x509 = x509_parse_cert(cert, binary) return x509.get_pubkey().get_rsa().as_pem() def x509_verify(cacert, cert, binary=False): "Validate the certificate's authenticity using a certification authority" ca = x509_parse_cert(cacert) crt = x509_parse_cert(cert, binary) return crt.verify(ca.get_pubkey()) if __name__ == "__main__": # basic test of enveloping signature (the reference is a part of the xml) sample_xml = """<Object xmlns="http://www.w3.org/2000/09/xmldsig#" Id="object">data</Object>""" output = canonicalize(sample_xml) print (output) vars = rsa_sign(sample_xml, '#object', "no_encriptada.key", "password") print (SIGNED_TMPL % vars) # basic test of enveloped signature (the reference is the document itself) sample_xml = """<?xml version="1.0" encoding="UTF-8"?><Object>data%s</Object>""" vars = rsa_sign(sample_xml % "", '', "no_encriptada.key", "password", sign_template=SIGN_ENV_TMPL, c14n_exc=False) print (sample_xml % (SIGNATURE_TMPL % vars)) # basic signature verification: public_key = x509_extract_rsa_public_key(open("zunimercado.crt").read()) assert rsa_verify(vars['signed_info'], vars['signature_value'], public_key, c14n_exc=False)

./Ninja\.