"Invalid RSAES-OAEP padding" Error

[petermikitsh]

Here's my SAML Configuration:

var samlStrategy = new saml.Strategy({
    callbackUrl: 'https://myServer.rit.edu/login/callback',
    entryPoint: 'https://shibboleth.main.ad.rit.edu/idp/profile/SAML2/Redirect/SSO',
    issuer: 'https://myServer.rit.edu/shibboleth',
    identifierFormat: null,
    decryptionPvk: fs.readFileSync('/var/www/saml/key.pem', 'utf8'),
    cert: 'MIIDV......'
}, function(profile, done) {
    return done(null, profile);
});

Routes:

app.get('/',
  passport.authenticate('saml', {failureRedirect: '/login/fail'}),
  function(req, res) {
    res.send('Authenticated');
  }
);

app.post('/login/callback',
   passport.authenticate('saml', { failureRedirect: '/login/fail' }),
  function(req, res) {
    res.redirect('/');
  }
);

General error catcher:

app.use(function(err, req, res, next){
    console.log('Express error!');
    console.log("the error: " + JSON.stringify(err));
    next(err);
});

Shibboleth processes the request and a SAMLResponse is present in the header of callback route, /login/callback.

An error is thrown at passport.authenticate('saml', {failureRedirect: '/login/fail'}) in the / route.
Console log:

Express error!
the error: {"message":"Invalid RSAES-OAEP padding."}

Any ideas?

[ploer]

Well, this is the error message you receive when the encrypted assertion does not match the private key you have supplied. I.e., your shibboleth provider has a public key for you that does not match the decryptionPvk you are supplying.

Not sure if that is what you are seeing here, but the poor error message has bitten me several times in the past, I've been meaning to look into what we can do to give a better error here. (it is being passed up from the underlying xmlenc library, not something generated directly by passport-saml)

[petermikitsh]

I've confirmed with my identity provider that the correct public key is on file.

[ploer]

Then the next debugging step that comes to mind would be to step into the xmlenc decrypt call (or add some debug logging), and check if everything looks correct in there.

It's definitely an error from the crypto layer, so if the right public key and private key are being used, I'd look at whether the private key is being loaded correctly, whether there is anything unusual about the format of those keys, etc.

[petermikitsh]

You are correct.

The XML module (xml-encryption) passes the encrypted data and private key to the 'forge' package:
https://github.com/auth0/node-xml-encryption/blob/master/lib/xmlenc.js#L208

Where the error is eventually thrown here:
https://github.com/digitalbazaar/forge/blob/master/js/pkcs1.js#L254

I might try re-generating a new public/private key pair, and coordinating with the IdP. However, I don't know what else could be causing this, but it isn't your package.

[petermikitsh]

For anyone who comes across this, try regenerating your keys and certificate-- that was my issue. Also, try configuring with something like testshib.org (see #10) first before having to annoy your IdP Admin to reload your metadata frequently :)

[ploer]

I should put something about how useful testshib can be for debugging in the docs. I'll file a bug for that.

[ricardosaracino]

Can someone point me in the direction of how to add aes256-cbc Assertion encryption support... i see this lib but not sure how to put it all together

https://github.com/auth0/node-xml-encryption