proxy

var DefaultOpt = Options{
	AuthProxy: "",
}

var Help = strings.Replace(`
### Auth Proxy

If you supply the parameter |--auth-proxy /path/to/program| then
rclone will use that program to generate backends on the fly which
then are used to authenticate incoming requests.  This uses a simple
JSON based protocol with input on STDIN and output on STDOUT.

**PLEASE NOTE:** |--auth-proxy| and |--authorized-keys| cannot be used
together, if |--auth-proxy| is set the authorized keys option will be
ignored.

There is an example program
[bin/test_proxy.py](https://github.com/Evengard/rclone/blob/master/bin/test_proxy.py)
in the rclone source code.

The program's job is to take a |user| and |pass| on the input and turn
those into the config for a backend on STDOUT in JSON format.  This
config will have any default parameters for the backend added, but it
won't use configuration from environment variables or command line
options - it is the job of the proxy program to make a complete
config.

This config generated must have this extra parameter
- |_root| - root to use for the backend

And it may have this parameter
- |_obscure| - comma separated strings for parameters to obscure

If password authentication was used by the client, input to the proxy
process (on STDIN) would look similar to this:

|||
{
	"user": "me",
	"pass": "mypassword"
}
|||

If public-key authentication was used by the client, input to the
proxy process (on STDIN) would look similar to this:

|||
{
	"user": "me",
	"public_key": "AAAAB3NzaC1yc2EAAAADAQABAAABAQDuwESFdAe14hVS6omeyX7edc...JQdf"
}
|||

And as an example return this on STDOUT

|||
{
	"type": "sftp",
	"_root": "",
	"_obscure": "pass",
	"user": "me",
	"pass": "mypassword",
	"host": "sftp.example.com"
}
|||

This would mean that an SFTP backend would be created on the fly for
the |user| and |pass|/|public_key| returned in the output to the host given.  Note
that since |_obscure| is set to |pass|, rclone will obscure the |pass|
parameter before creating the backend (which is required for sftp
backends).

The program can manipulate the supplied |user| in any way, for example
to make proxy to many different sftp backends, you could make the
|user| be |[email protected]| and then set the |host| to |example.com|
in the output and the user to |user|. For security you'd probably want
to restrict the |host| to a limited list.

Note that an internal cache is keyed on |user| so only use that for
configuration, don't use |pass| or |public_key|.  This also means that if a user's
password or public-key is changed the cache will need to expire (which takes 5 mins)
before it takes effect.

This can be used to build general purpose proxies to any kind of
backend that rclone supports.  
`, "|", "`", -1)