Hi Satosa users, 

I’m having trouble with a SAML request being incorrectly inflated/decoded and then failing with the error “invalid signature” (which I think is misleading). I couldn’t see a known issue about this on GitHub. I’m running Satosa 8.2. Has anyone seen this and has a suggestion? 

Both the good and bad AuthN Requests in the logs below validate fine at https://www.samltool.com/decode.php  

Example, “bad” encoding from https://sptest.iamshowcase.com/instructions: 

[1687184930.586361] [2023-06-19 14:28:50] [DEBUG]: read request data: {'SAMLRequest': 'fVFbb4IwFP4rTd/lUrVCIyRsZhmJZkbYHvZWSh1NoGU9ZdvPH6Jm7sXHk+98t3PWwLu2Z9ngGn2Qn4MEh366VgObgAQPVjPDQQHTvJPAnGBFttsy4gWst8YZYVp8Q7nP4ADSOmU0Rk/GCjn5JvjIW5AYoXyTYB7VhNdRTOpFSGkYrZYhJTSIBa9EFR/JPKLVKpSUYpQDDDLX4Lh2CSYBmc8COgvjMlwwErFl8I7RZmykND95Jrhxrgfm+6ruPSGt9kTjn0IT6H0A4/cGHEbZNeSj0TB00hbSfikhXw/bPwno3ajsKd5BY74FB+kJ0/lcwNhjfznMg9K10h/3b1Kdl4A9l+V+tn8pylEBvUkLU+ZxBafrU0o29bUozbNdcTFd+zdIep7+vzP9BQ=='}

...

[1687184930.589399] [2023-06-19 14:28:50] [DEBUG]: xmlstr: b'}Q[o\x820\x14\xfe+M\xdf\xe5R\xb5B#$lf\x19\x89fF\xd8\x1e\xf6VJ\x1dM\xa0e=e\xdb\xcf\x1f\xa2f\xee\xc5\xc7\x93\xef|\xb7s\xd6\xc0\xbb\xb6g\xd9\xe0\x1a}\x90\x9f\x83\x04\x87~\xbaV\x03\x9b\x80\x04\x0fV3\xc3A\x01\xd3\xbc\x93\xc0\x9c`E\xb6\xdb2\xe2\x05\xac\xb7\xc6\x19aZ|C\xb9\xcf\xe0\x00\xd2:e4FO\xc6\n9\xf9&\xf8\xc8[\x90\x18\xa1|\x93`\x1e\xd5\x84\xd7QL\xeaEHi\x18\xad\x96!%4\x88\x05\xafD\x15\x1f\xc9<\xa2\xd5*\x94\x94b\x94\x03\x0c2\xd7\xe0\xb8v\t&\x01\x99\xcf\x02:\x0b\xe32\\0\x12\xb1e\xf0\x8e\xd1fl\xa44?y&\xb8q\xae\x07\xe6\xfb\xaa\xee=!\xad\xf6D\xe3\x9fB\x13\xe8}\x00\xe3\xf7\x06\x1cF\xd95\xe4\xa3\xd10t\xd2\x16\xd2~)!_\x0f\xdb?\t\xe8\xdd\xa8\xec)\xdeAc\xbe\x05\x07\xe9\t\xd3\xf9\\\xc0\xd8c\x7f9\xcc\x83\xd2\xb5\xd2\x1f\xf7oR\x9d\x97\x80=\x97\xe5~\xb6\x7f)\xcaQ\x01\xbdI\x0bS\xe6q\x05\xa7\xebSJ6\xf5\xb5(\xcd\xb3]q1]\xfb7Hz\x9e\xfe\xbf3\xfd\x05', relay_state: None, sigalg: None, signature: None


Example “good” encoding from https://samltest.id/saml-test/: 

[1687184991.342228] [2023-06-19 14:29:51] [DEBUG]: read request data: {'SAMLRequest': 'fZHdT4MwFMX/FdL3UejGJs0gwe3BJVPJQB98MaUUaQIt9hY//nv50DgTs7cmPed37j13C6xtOpr0tlYn8doLsM5H2yig00eEeqOoZiCBKtYKoJbTLLk9UuJ6tDPaaq4b5CQAwlip1U4r6FthMmHeJBcPp2OEams7oBiPRDsEuLLEWS2LQjfC1i6AxiOS4PQ+y5GzHyRSsZH265Vl53JhlMvriUOgw6PRiFIawS1yDvsIPa+qDd+EVyUjgR/6q6AI+bJaE1IUPqlKLxhkAL04KLBM2QgRjywX3nrhh7m/oiSkgf+EnPR7r2upSqleLpdQzCKgN3meLuYVHoWBafxBgOLtODCdgs1ZuZex7KdRFP/X3/jG0G3xGXsO6ujdADvsU91I/ukkTaPfd0YwKyLkIxzPlr8nj78A', 'RelayState': 'ss:mem:a06bd083cf6e2d94f28cccd470c97390dc2ccf20657a3be36e36bce4521e8cdd’}

...

[1687184991.345231] [2023-06-19 14:29:51] [DEBUG]: xmlstr: b'<samlp:AuthnRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" AssertionConsumerServiceURL="https://samltest.id/Shibboleth.sso/SAML2/POST" Destination="https://idp.cern.ch/saml2sp/sso/redirect" ID="_4f7c798da2519145b9c3f622bb12fd05" IssueInstant="2023-06-19T14:29:51Z" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Version="2.0"><saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">https://samltest.id/saml/sp</saml:Issuer><samlp:NameIDPolicy AllowCreate="1"/></samlp:AuthnRequest>', relay_state: None, sigalg: None, signature: None


Thanks for any help!

Hannah