Alternate CSV delimiters not URL encoded/decoded

[cpiker]

I don't want to post specific server URLs here, so a description follows instead.

1. Go to any ephemeris data source, tracers or otherwise
2. Select a time region and interval appropriate to the mission at hand
3. Before hitting download change the default delimiter to ';'
4. Downloads will fail with the following exceptions

<exception type="BadRequest" message="Illegal character(s) in the value for query parmeter: format.delim" />

<exception type="BadRequest" message="One or more of the query parameters looks like a shell injection attack, data output halted." />

Looks like special characters aren't getting URL encoded/decoded and trigger the shell-injection-attack parameter value checker.

[cpiker]

Even better, the das stream header is being emitted before HTTP header, which is bad news. Full response follows:

[00]000025<stream version="2.2" />
[xx]000109<exception type="BadRequest" message="Illegal character(s) in the value for query parmeter: format.delim" />
Status: 400 Bad Request
Content-Type: text/vnd.das2.das2stream

[00]000025<stream version="2.2" />
[xx]000135<exception type="BadRequest" message="One or more of the query parameters looks like a shell injection attack, data output halted." />

The Status: line should of course be first.

[KaiwenS7]

I've done a bit of digging here. There's 2 issues:

1. The illegal character(s) issue is an encoding issue on the front-end. That part can be fixed with encodeURIComponent() for semicolon, but not for pipe. Pipe has it's own issues apparently when it comes to following the RFC. I'd need to look at this mark, since the encoded params also might not be handled by the server correctly either.
2. The das3_csv command doesn't handle non-default arguments well. Gets the result "Invalid query, upstream data producer not triggered, command pipeline is 'das3_csv'". Reason that comma works is because it doesn't send any format.delim query parameter, so the default behavior is used.

Recommendation: Changing das3_csv to accept string names of standard delimiters would be useful to circumvent the issue without changing any behavior for existing process calls. So, similar to how "format.delim=tab" is sent for using tab delimiters, "|" can be sent as "format.delim=pipe" and ";" can be sent as "format.delim=semi".

[cpiker]

I like this idea for das3_csv in general. Trying to move to a 3.0 das2C, will get this in there before 3.0 release on github.