Skip to main content

Python XML Signature library

Project description

SignXML is an implementation of the W3C XML Signature standard in Python (both “Second Edition” and Version 1.1). This standard (also known as XMLDSig and RFC 3275) is used to provide payload security in SAML 2.0, among other uses. SignXML implements all of the required components of the standard, and most recommended ones. Its features are:

  • Use of defusedxml.lxml to defend against common XML-based attacks when verifying signatures

  • Extensions to allow signing with and verifying X.509 certificate chains, including hostname/CN validation

  • Support for exclusive XML canonicalization with inclusive prefixes (InclusiveNamespaces PrefixList, required to verify signatures generated by some SAML implementations)

  • Modern Python compatibility (2.7-3.4+ and PyPy)

  • Well-supported, portable, reliable dependencies: lxml, defusedxml, cryptography, eight, pyOpenSSL

  • Comprehensive testing (including the XMLDSig interoperability suite) and continuous integration

  • Simple interface with useful defaults

  • Compactness, readability, and extensibility

Installation

pip install signxml

Note: SignXML depends on lxml and cryptography, which in turn depend on OpenSSL, LibXML, and Python tools to interface with them. On Ubuntu, you can install those with:

apt-get install python-dev libxml2-dev libxslt1-dev libssl-dev python-cffi

Synopsis

SignXML uses the ElementTree API (also supported by lxml) to work with XML data.

from signxml import xmldsig

cert = open("example.pem").read()
key = open("example.key").read()
root = ElementTree.fromstring(signature_data)
xmldsig(root).sign(key=key, cert=cert)
verified_data = xmldsig(root).verify()

Verifying SAML assertions

Assuming metadata.xml contains SAML metadata for the assertion source:

from lxml import etree
from base64 import b64decode
from signxml import xmldsig

with open("metadata.xml", "rb") as fh:
    cert = etree.parse(fh).find("//ds:X509Certificate").text

assertion_data = xmldsig(b64decode(assertion_body)).verify(x509_cert=cert)

Detached signatures

The XML Signature specification requires support of detached signatures, where the signature document refers (in <Reference URI="...">) to an external document. SignXML does not support generating detached signatures. To verify a detached signature, pass a resolver callable to the xmldsig.verify() method.

See the API documentation for more.

Authors

  • Andrey Kislyuk

License

Licensed under the terms of the Apache License, Version 2.0.

https://travis-ci.org/kislyuk/signxml.svg https://coveralls.io/repos/kislyuk/signxml/badge.svg?branch=master https://pypip.in/v/signxml/badge.svg https://pypip.in/d/signxml/badge.svg https://readthedocs.org/projects/signxml/badge/?version=latest

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

signxml-0.3.7.tar.gz (141.3 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page