使用Python/M2Crypto的SAML签名验证 [英] SAML signature verification using Python/M2Crypto

问题描述

我正在尝试使用M2Crypto来验证django/python应用程序中从我的SSO/SAML提供程序返回的XML响应中包含的签名，但是我似乎无法使其正常工作.

I'm attempting to use M2Crypto to verify a signature contained in an XML response returned from my SSO/SAML provider in my django/python app, but I can't seem to get it to work.

我的XML响应看起来类似于第二个示例这里.

My XML response looks sort of like the second example here.

ETA:和这是我实际XML的粘贴框.

ETA: And here's a pastebin of my actual XML.

我正在使用类似这样的代码来尝试验证:

I'm using some code like this to attempt the verification:

def verify_signature(signed_info, cert, signature):
    from M2Crypto import EVP, RSA, X509

    x509 = X509.load_cert_string(base64.decodestring(cert), X509.FORMAT_DER)
    pubkey = x509.get_pubkey().get_rsa()
    verify_EVP = EVP.PKey()
    verify_EVP.assign_rsa(pubkey)
    verify_EVP.reset_context(md='sha1')
    verify_EVP.verify_init()

    verify_EVP.verify_update(signature.decode('base64'))
    result = verify_EVP.verify_final(signed_info)

    return result

我可以从响应中成功获取NameID，并且我知道我已经成功加载了证书，因为我可以从中取出颁发者等.

I can successfully get the NameID from the response, and I know I'm successfully loading the certificate, because I can pull the issuer, etc. out of it.

但是，对于签名，我尝试对传入的XML进行哈希处理，对各种片段进行编码/不编码，并为signed_info参数(SignedInfo标记，Response标记，整个过程)，而我尝试使用ElementTree/ ElementC14N.py 来确保XML完全规范化，正如Transform所暗示的那样，但是我没有得到积极的结果.

As for the signature, though, I've tried hashing the passed in XML, encoding/not encoding various pieces, and passing in various bits of XML for the signed_info parameter (the SignedInfo tag, the Response tag, the whole thing), and I've tried using ElementTree/ElementC14N.py to ensure the XML is exclusively canonicalized, as the Transform implies should be done, but I'm not getting a positive result.

我在这里想念什么?我是否要针对错误的XML进行验证?我的验证技术出了什么问题?

What am I missing here? Am I trying to validate against the wrong XML? Something wrong with my verification technique?

推荐答案

您是如此亲密！您应该传递给verify_updatesigned_info，然后传递给verify_final传递签名.

You were so close! You should pass to verify_update the signed_info, and then to verify_final pass the signature.

在验证签名之前，您需要确保正确签名了您的signed_info.

You do need to make sure that your signed_info is correctly canonicalized before verifying the signature.

这是正确的方法:

def verify_signature(signed_info, cert, signature):
    from M2Crypto import EVP, RSA, X509

    x509 = X509.load_cert_string(base64.decodestring(cert), X509.FORMAT_DER)
    pubkey = x509.get_pubkey().get_rsa()
    verify_EVP = EVP.PKey()
    verify_EVP.assign_rsa(pubkey)
    verify_EVP.reset_context(md='sha1')
    verify_EVP.verify_init()

    verify_EVP.verify_update(signed_info)
    result = verify_EVP.verify_final(signature.decode('base64'))

    return result

这篇关于使用Python/M2Crypto的SAML签名验证的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！