This commits dds 3 separate, but very related features:
1. Automated server identity management
How do you know you're connecting to the server you think you are? How do you know the server connecting to you is the server instance you think it is? Mutually-authenticated TLS (mTLS) answers both of these questions. Using TLS to authenticate requires a public/private key pair (and the peer must trust the certificate you present to it).
Fortunately, Caddy is really good at managing certificates by now. We tap into that power to make it possible for Caddy to obtain and renew its own identity credentials, or in other words, a certificate that can be used for both server verification when clients connect to it, and client verification when it connects to other servers. Its associated private key is essentially its identity, and TLS takes care of possession proofs.
This configuration is simply a list of identifiers and an optional list of custom certificate issuers. Identifiers are things like IP addresses or DNS names that can be used to access the Caddy instance. The default issuers are ZeroSSL and Let's Encrypt, but these are public CAs, so they won't issue certs for private identifiers. Caddy will simply manage credentials for these, which other parts of Caddy can use, for example: remote administration or dynamic config loading (described below).
2. Remote administration over secure connection
This feature adds generic remote admin functionality that is safe to expose on a public interface.
- The "remote" (or "secure") endpoint is optional. It does not affect the standard/local/plaintext endpoint.
- It's the same as the [API endpoint on localhost:2019](https://caddyserver.com/docs/api), but over TLS.
- TLS cannot be disabled on this endpoint.
- TLS mutual auth is required, and cannot be disabled.
- The server's certificate _must_ be obtained and renewed via automated means, such as ACME. It cannot be manually loaded.
- The TLS server takes care of verifying the client.
- The admin handler takes care of application-layer permissions (methods and paths that each client is allowed to use).\
- Sensible defaults are still WIP.
- Config fields subject to change/renaming.
3. Dyanmic config loading at startup
Since this feature was planned in tandem with remote admin, and depends on its changes, I am combining them into one PR.
Dynamic config loading is where you tell Caddy how to load its config, and then it loads and runs that. First, it will load the config you give it (and persist that so it can be optionally resumed later). Then, it will try pulling its _actual_ config using the module you've specified (dynamically loaded configs are _not_ persisted to storage, since resuming them doesn't make sense).
This PR comes with a standard config loader module called `caddy.config_loaders.http`.
Caddyfile config for all of this can probably be added later.
COMMITS:
* admin: Secure socket for remote management
Functional, but still WIP.
Optional secure socket for the admin endpoint is designed
for remote management, i.e. to be exposed on a public
port. It enforces TLS mutual authentication which cannot
be disabled. The default port for this is :2021. The server
certificate cannot be specified manually, it MUST be
obtained from a certificate issuer (i.e. ACME).
More polish and sensible defaults are still in development.
Also cleaned up and consolidated the code related to
quitting the process.
* Happy lint
* Implement dynamic config loading; HTTP config loader module
This allows Caddy to load a dynamic config when it starts.
Dynamically-loaded configs are intentionally not persisted to storage.
Includes an implementation of the standard config loader, HTTPLoader.
Can be used to download configs over HTTP(S).
* Refactor and cleanup; prevent recursive config pulls
Identity management is now separated from remote administration.
There is no need to enable remote administration if all you want is identity
management, but you will need to configure identity management
if you want remote administration.
* Fix lint warnings
* Rename identities->identifiers for consistency
Allows user to disable OCSP stapling (including support in the Caddyfile via the ocsp_stapling global option) or overriding responder URLs. Useful in environments where responders are not reachable due to firewalls.
This allows for finer-grained control when choosing alternate chains than
simply the previous/Certbot-esque behavior of "choose first chain that
contains an issuer's common name." This update allows you to sort by
length (if optimizing for efficiency on the wire) and also to select the
chain with a specific root CommonName.
* caddytls: Support multiple issuers
Defaults are Let's Encrypt and ZeroSSL.
There are probably bugs.
* Commit updated integration tests, d'oh
* Update go.mod
Update internal issuer for compatibility -- yay simpler code!
The .1 version also fixes non-critical SAN extensions that caused trust
issues on several clients.
* ci: Try Go 1.15 RC1 out of curiosity
* Go 1.15 was released; let's try it
* Update to latest quic-go
* Attempt at fixing broken test
Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>
* caddytls: Add support for ZeroSSL; add Caddyfile support for issuers
Configuring issuers explicitly in a Caddyfile is not easily compatible
with existing ACME-specific parameters such as email or acme_ca which
infer the kind of issuer it creates (this is complicated now because
the ZeroSSL issuer wraps the ACME issuer)... oh well, we can revisit
that later if we need to.
New Caddyfile global option:
{
cert_issuer <name> ...
}
Or, alternatively, as a tls subdirective:
tls {
issuer <name> ...
}
For example, to use ZeroSSL with an API key:
{
cert_issuser zerossl API_KEY
}
For now, that still uses ZeroSSL's ACME endpoint; it fetches EAB
credentials for you. You can also provide the EAB credentials directly
just like any other ACME endpoint:
{
cert_issuer acme {
eab KEY_ID MAC_KEY
}
}
All these examples use the new global option (or tls subdirective). You
can still use traditional/existing options with ZeroSSL, since it's
just another ACME endpoint:
{
acme_ca https://acme.zerossl.com/v2/DV90
acme_eab KEY_ID MAC_KEY
}
That's all there is to it. You just can't mix-and-match acme_* options
with cert_issuer, because it becomes confusing/ambiguous/complicated to
merge the settings.
* Fix broken test
This test was asserting buggy behavior, oops - glad this branch both
discovers and fixes the bug at the same time!
* Fix broken test (post-merge)
* Update modules/caddytls/acmeissuer.go
Fix godoc comment
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* Add support for ZeroSSL's EAB-by-email endpoint
Also transform the ACMEIssuer into ZeroSSLIssuer implicitly if set to
the ZeroSSL endpoint without EAB (the ZeroSSLIssuer is needed to
generate EAB if not already provided); this is now possible with either
an API key or an email address.
* go.mod: Use latest certmagic, acmez, and x/net
* Wrap underlying logic rather than repeating it
Oops, duh
* Form-encode email info into request body for EAB endpoint
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
* cel: fix validation of expression result type
The earlier code used the proto.Equals from github.com/gogo/protobuf, which failed to compare two messages of the same type for some reason. Switching to proto.Equal from the canonical github.com/golang/protobuf fixes the issue.
* deps: remove deprecated github.com/golang/protobuf in favor of google.golang.org/protobuf
* downgrade github.com/smallstep/nosql to resolve warning pb.proto warning
* pki: Initial commit of embedded ACME server (#3021)
* reverseproxy: Support auto-managed TLS client certificates (#3021)
* A little cleanup after today's review session
Moving to https://github.com/caddyserver/circuitbreaker
Nobody was using it anyway -- it works well, but something got fumbled
in a refactoring *months* ago. Turns out that we forgot the interface
guards AND botched a method name (my bad) - Ok() should have been OK().
So it would always have thrown a runtime panic if it tried to be loaded.
The module itself works well, but obviously nobody used it because
nobody reported the error. Fixing this while we move it to the new repo.
Removing this removes the last Bazaar/Launchpad dependency (I think).
Simão Gomes Viana