`isValidOrigin` cannot handle origin string with a port number

[cmurphy]

Description

An origin string like '127.0.0.1:8000' should be a valid submission prefix according to the specification. However, isValidOrigin returns an error, because it cannot parse it as a schema-less URL:

Can't initialize CT HTTP Server: newLog(): origin "127.0.0.1:8000" is not valid: can't parse origin as an URL: parse "127.0.0.1:8000": first path segment in URL cannot contain colon

Adding a schema prefix of course results in an error as well.

I think using url.Parse is not the best option for this validation check because it cannot recognize a URL that includes a non-standard port if the URL does not have a scheme.

[phbnf]

Thanks for raising this. I looks like the right way to indicate to url.Parse that an URL is schema-less it to prefix it with //, so it should probably do that for the purpose of calling that function.

As you've seen in specs, the submission prefix MUST be the origin. When doing local development, or before making a log public, the submission prefix is likely to change as the infrastructure around the log changes. TesseraCT should allow you to use an origin that doesn't match with the URL used to speak to the log. You can even customize this further using the path_prefix flag.