Configuration key interoperability problem

[lupari]

Hi,

We have implemented Configuration Key hash generation in our e-assessment application about two years ago. The file our server generates works perfectly with the SEB MacOS client. However now that the Windows client also started supporting the config key we have discovered that the same file that works with MacOS client does not work with any of the Windows clients. I got some logs from the windows client when trying to open the generated file:

2021-08-16 14:17:26.212 [07] - DEBUG: [BinaryParser] 'System.IO.FileStream' starting with 'pswd' matches the Binary format. 2021-08-16 14:17:26.213 [07] - DEBUG: [GZipCompressor] Starting decompression of 'System.IO.FileStream' with 2,141 KB data... 2021-08-16 14:17:26.213 [07] - DEBUG: [GZipCompressor] Successfully decompressed 2,141 KB to 2,118 KB data. 2021-08-16 14:17:26.214 [07] - DEBUG: [BinaryParser] Attempting to parse password block with prefix 'pswd'... 2021-08-16 14:17:26.214 [07] - DEBUG: [PasswordEncryption] Parsing encryption header... 2021-08-16 14:17:26.215 [07] - DEBUG: [PasswordEncryption] Unknown encryption header! Expected: [2,1,...] - Actual: [3,1,...] 2021-08-16 14:17:26.216 [07] - DEBUG: [PasswordEncryption] Generating keys for authentication and decryption... 2021-08-16 14:17:26.356 [07] - DEBUG: [PasswordEncryption] Generating HMACs for authentication... 2021-08-16 14:17:26.357 [07] - DEBUG: [PasswordEncryption] Decrypting data... 2021-08-16 14:17:26.358 [07] - DEBUG: [GZipCompressor] Starting decompression of 'System.IO.MemoryStream' with 2,042 KB data... 2021-08-16 14:17:26.358 [07] - DEBUG: [GZipCompressor] Successfully decompressed 2,042 KB to 8,773 KB data. 2021-08-16 14:17:26.359 [07] - DEBUG: [BinaryParser] Attempting to parse plain data block... 2021-08-16 14:17:26.360 [07] - ERROR: [XmlParser] 'System.IO.MemoryStream' starting with '<pli' does not match the Xml format! 2021-08-16 14:17:26.361 [07] - INFO: [ConfigurationRepository] Tried to parse data from 'System.IO.FileStream' using BinaryParser -> Result: InvalidData. 2021-08-16 14:19:17.318 [07] - WARNING: The configuration has failed!
Seems that the configuration is decompressed and decrypted properly and the problem is with the actual PLIST format.

Attached is a configuration we use as a base template. As said the OSX client has no problems with it.
seb-config.txt

Any help would be appreciated. Thank you :)

[dbuechel]

Accroding to the log, the unecrypted, plain data lacks the XML header and directly starts with <plist>.... The file you linked above should be correct, for guidance you could also have a look at the unit test data in the source code itself:

https://github.com/SafeExamBrowser/seb-win-refactoring/blob/master/SafeExamBrowser.Configuration.UnitTests/DataFormats/XmlTestData.xml
https://github.com/SafeExamBrowser/seb-win-refactoring/blob/master/SafeExamBrowser.Configuration.UnitTests/DataFormats/XmlTestSettings.xml

[lupari]

Looks like that is the case indeed. Did some debugging and the XML header got discarded on our server while converting the template file into XML document (for some preprocessing purposes) before generating the actual SEB file. I got that fixed now, hope this fixes our problem. Bit confusing though that MacOS client didn't mind the missing header.

Thanks for your help. Will report back when we have test results (takes a while because I don't have a Windows computer to test with).

edit: Yes, that did the trick 👍