Allow reading CA from memory as well as from a path in verify function

[astitt-ripple]

This is a follow-up my prior PR #44

It allows the caller to pass in buffers for the cert and ca instead of paths to the verify function.

Some JS code detects whether the cert and ca are files or buffers, and if they are files, reads them to a buffer first. I augmented the tests to verify any combination of file/buffer should work.

Also I found some cases where error code-paths would not fully clean up allocated memory or clear error statuses, those changes for the verify function are included here. I'm filing a separate PR with some similar cleanup to the parseCert function.

These modifications have been working very well for my use-case, and I would like to offer them back.

cc @Southern

[astitt-ripple]

@Southern Are there any changes you'd like to see here? No rush, just hoping to close out this PR if possible.

[astitt-ripple]

Closing due to inactivity.

@Southern feel free to re-open at any point if this is useful (or request changes). Thanks.

[Southern]

My apologies, @astitt-ripple. I got a new job right after I sent you the last message in the other PR and have been totally swamped with it.

[astitt-ripple]

congrats on the new job @Southern!

[Southern]

Thanks! Hopefully I can get to this soon since this project at work is about to be released.

[scottmas]

@Southern Any update on this? This would be super handy. My use case involves sending a certificate through the http headers, thus it's pretty inconvenient to have to write it to file.

[Southern]

I’ll take a look at it as soon as possible, most likely this weekend. I sincerely apologize to you all that have been waiting for this. Not only did I get a new job, as previously mentioned, I was put in charge of managing the entire project and have been extremely busy with that.

[scottmas]

No worries friend. Maintaining an open source project is a lot of work. I also just opened a new PR with a few tweaks (mostly following Javascript conventions a bit more)

[astitt-ripple]

Thanks for picking this up and polishing it off @scottmas

I'm glad you find the added functionality useful.