[NTC-4957] Fixed parsing Palo banners that start on the same line

[joewesch]

Closes: #780

This PR changes the logic a bit when dealing with Palo Alto banners that start on the same line as login-banner. The existing test only tests if they start with an empty line:

          login-banner "
************************************************************************

But a banner isn't required to have a blank line on the first line.

          login-banner "####################################################
WARNING TO UNAUTHORIZED USERS:

[itdependsnetworks]

Can you add a ConfigLine output of this as well? Want to make sure it renders correctly. Otherwise, looks good :)

[jeffkala]

just checking, @joewesch does everything work with a very short 1 line banner?

login-banner "BANNER"

I'd assume above is a valid banner and want to make sure the parsing isn't dependent on multilines.

[joewesch]

just checking, @joewesch does everything work with a very short 1 line banner?

login-banner "BANNER"

I'd assume above is a valid banner and want to make sure the parsing isn't dependent on multilines.

Ah, good call. It does not. Let me add a test for that and then fix it.

[joewesch]

I moved this back to draft for now. I determined that the current parsing logic does not account for single line banners so I'm going to need to create many more tests and verify they are all parsed correctly.

[joewesch]

After discovering that single line banners were not being properly parsed, I have refactored the config parsing to instead key off of set being at the beginning of every config line. This made the logic much simpler and more efficient. I have added a myriad of test cases for both converting brace format config to set format as well as for parsing the set format banners.

As mentioned in the comments in the code, this includes 2x points that could cause false positives:

• When converting the brace config banner and a line in the multi-line banner ends with the delimiter and a semicolon (e.g., ";, ';, ;).
• When parsing the set config banner and a line in the multi-line banner starts with set .

These should be considered edge cases and are easy to fix by simply adjusting the wording in the banner.

[jeffkala]

Oh yea baby!!