caddytls: Add support for ZeroSSL; add Caddyfile support for issuers (#…

…3633)

* 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>

caddyconfig/httpcaddyfile/builtins.go

@@ -29,6 +29,7 @@ import (
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
 	"github.com/caddyserver/caddy/v2/modules/caddytls"
+	"github.com/caddyserver/certmagic"
 	"github.com/mholt/acmez/acme"
 	"go.uber.org/zap/zapcore"
 )
@@ -76,6 +77,7 @@ func parseBind(h Helper) ([]ConfigValue, error) {
 //         ca_root   <pem_file>
 //         dns       <provider_name>
 //         on_demand
+//         issuer <module_name> ...
 //     }
 //
 func parseTLS(h Helper) ([]ConfigValue, error) {
@@ -85,6 +87,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 	var certSelector caddytls.CustomCertSelectionPolicy
 	var acmeIssuer *caddytls.ACMEIssuer
 	var internalIssuer *caddytls.InternalIssuer
+	var issuer certmagic.Issuer
 	var onDemand bool
 
 	for h.Next() {
@@ -276,6 +279,28 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 					MACKey: arg[1],
 				}
 
+			case "issuer":
+				if !h.NextArg() {
+					return nil, h.ArgErr()
+				}
+				modName := h.Val()
+				mod, err := caddy.GetModule("tls.issuance." + modName)
+				if err != nil {
+					return nil, h.Errf("getting issuer module '%s': %v", modName, err)
+				}
+				unm, ok := mod.New().(caddyfile.Unmarshaler)
+				if !ok {
+					return nil, h.Errf("issuer module '%s' is not a Caddyfile unmarshaler", mod.ID)
+				}
+				err = unm.UnmarshalCaddyfile(h.NewFromNextSegment())
+				if err != nil {
+					return nil, err
+				}
+				issuer, ok = unm.(certmagic.Issuer)
+				if !ok {
+					return nil, h.Errf("module %s is not a certmagic.Issuer", mod.ID)
+				}
+
 			case "dns":
 				if !h.NextArg() {
 					return nil, h.ArgErr()
@@ -350,7 +375,24 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 		// the logic to support this would be complex
 		return nil, h.Err("cannot use both ACME and internal issuers in same server block")
 	}
-	if acmeIssuer != nil {
+	if issuer != nil && (acmeIssuer != nil || internalIssuer != nil) {
+		// similarly, the logic to support this would be complex
+		return nil, h.Err("when defining an issuer, all its config must be in its block, rather than from separate tls subdirectives")
+	}
+	switch {
+	case issuer != nil:
+		configVals = append(configVals, ConfigValue{
+			Class: "tls.cert_issuer",
+			Value: issuer,
+		})
+
+	case internalIssuer != nil:
+		configVals = append(configVals, ConfigValue{
+			Class: "tls.cert_issuer",
+			Value: internalIssuer,
+		})
+
+	case acmeIssuer != nil:
 		// fill in global defaults, if configured
 		if email := h.Option("email"); email != nil && acmeIssuer.Email == "" {
 			acmeIssuer.Email = email.(string)
@@ -361,15 +403,9 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 		if caPemFile := h.Option("acme_ca_root"); caPemFile != nil {
 			acmeIssuer.TrustedRootsPEMFiles = append(acmeIssuer.TrustedRootsPEMFiles, caPemFile.(string))
 		}
-
 		configVals = append(configVals, ConfigValue{
 			Class: "tls.cert_issuer",
-			Value: acmeIssuer,
-		})
-	} else if internalIssuer != nil {
-		configVals = append(configVals, ConfigValue{
-			Class: "tls.cert_issuer",
-			Value: internalIssuer,
+			Value: disambiguateACMEIssuer(acmeIssuer),
 		})
 	}
 

caddyconfig/httpcaddyfile/options.go

@@ -20,6 +20,7 @@ import (
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	"github.com/caddyserver/caddy/v2/modules/caddytls"
+	"github.com/caddyserver/certmagic"
 	"github.com/mholt/acmez/acme"
 )
 
@@ -35,6 +36,7 @@ func init() {
 	RegisterGlobalOption("acme_ca_root", parseOptSingleString)
 	RegisterGlobalOption("acme_dns", parseOptSingleString)
 	RegisterGlobalOption("acme_eab", parseOptACMEEAB)
+	RegisterGlobalOption("cert_issuer", parseOptCertIssuer)
 	RegisterGlobalOption("email", parseOptSingleString)
 	RegisterGlobalOption("admin", parseOptAdmin)
 	RegisterGlobalOption("on_demand_tls", parseOptOnDemand)
@@ -210,6 +212,33 @@ func parseOptACMEEAB(d *caddyfile.Dispenser) (interface{}, error) {
 	return eab, nil
 }
 
+func parseOptCertIssuer(d *caddyfile.Dispenser) (interface{}, error) {
+	if !d.Next() { // consume option name
+		return nil, d.ArgErr()
+	}
+	if !d.Next() { // get issuer module name
+		return nil, d.ArgErr()
+	}
+	modName := d.Val()
+	mod, err := caddy.GetModule("tls.issuance." + modName)
+	if err != nil {
+		return nil, d.Errf("getting issuer module '%s': %v", modName, err)
+	}
+	unm, ok := mod.New().(caddyfile.Unmarshaler)
+	if !ok {
+		return nil, d.Errf("issuer module '%s' is not a Caddyfile unmarshaler", mod.ID)
+	}
+	err = unm.UnmarshalCaddyfile(d.NewFromNextSegment())
+	if err != nil {
+		return nil, err
+	}
+	iss, ok := unm.(certmagic.Issuer)
+	if !ok {
+		return nil, d.Errf("module %s is not a certmagic.Issuer", mod.ID)
+	}
+	return iss, nil
+}
+
 func parseOptSingleString(d *caddyfile.Dispenser) (interface{}, error) {
 	d.Next() // consume parameter name
 	if !d.Next() {

caddyconfig/httpcaddyfile/tlsapp.go

@@ -21,6 +21,7 @@ import (
 	"reflect"
 	"sort"
 	"strconv"
+	"strings"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig"
@@ -135,8 +136,11 @@ func (st ServerType) buildTLSApp(
 				// issuer, skip, since we intend to adjust only ACME issuers
 				var acmeIssuer *caddytls.ACMEIssuer
 				if ap.Issuer != nil {
-					var ok bool
-					if acmeIssuer, ok = ap.Issuer.(*caddytls.ACMEIssuer); !ok {
+					// ensure we include any issuer that embeds/wraps an underlying ACME issuer
+					type acmeCapable interface{ GetACMEIssuer() *caddytls.ACMEIssuer }
+					if acmeWrapper, ok := ap.Issuer.(acmeCapable); ok {
+						acmeIssuer = acmeWrapper.GetACMEIssuer()
+					} else {
 						break
 					}
 				}
@@ -348,6 +352,8 @@ func (st ServerType) buildTLSApp(
 // returned if there are no default/global options. However, if always is
 // true, a non-nil value will always be returned (unless there is an error).
 func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddyconfig.Warning, always bool) (*caddytls.AutomationPolicy, error) {
+	issuer, hasIssuer := options["cert_issuer"]
+
 	acmeCA, hasACMECA := options["acme_ca"]
 	acmeCARoot, hasACMECARoot := options["acme_ca_root"]
 	acmeDNS, hasACMEDNS := options["acme_dns"]
@@ -357,7 +363,7 @@ func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddycon
 	localCerts, hasLocalCerts := options["local_certs"]
 	keyType, hasKeyType := options["key_type"]
 
-	hasGlobalAutomationOpts := hasACMECA || hasACMECARoot || hasACMEDNS || hasACMEEAB || hasEmail || hasLocalCerts || hasKeyType
+	hasGlobalAutomationOpts := hasIssuer || hasACMECA || hasACMECARoot || hasACMEDNS || hasACMEEAB || hasEmail || hasLocalCerts || hasKeyType
 
 	// if there are no global options related to automation policies
 	// set, then we can just return right away
@@ -369,8 +375,16 @@ func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddycon
 	}
 
 	ap := new(caddytls.AutomationPolicy)
+	if keyType != nil {
+		ap.KeyType = keyType.(string)
+	}
 
-	if localCerts != nil {
+	if hasIssuer {
+		if hasACMECA || hasACMEDNS || hasACMEEAB || hasEmail || hasLocalCerts {
+			return nil, fmt.Errorf("global options are ambiguous: cert_issuer is confusing when combined with acme_*, email, or local_certs options")
+		}
+		ap.Issuer = issuer.(certmagic.Issuer)
+	} else if localCerts != nil {
 		// internal issuer enabled trumps any ACME configurations; useful in testing
 		ap.Issuer = new(caddytls.InternalIssuer) // we'll encode it later
 	} else {
@@ -402,15 +416,25 @@ func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddycon
 		if acmeEAB != nil {
 			mgr.ExternalAccount = acmeEAB.(*acme.EAB)
 		}
-		if keyType != nil {
-			ap.KeyType = keyType.(string)
-		}
-		ap.Issuer = mgr // we'll encode it later
+		ap.Issuer = disambiguateACMEIssuer(mgr) // we'll encode it later
 	}
 
 	return ap, nil
 }
 
+// disambiguateACMEIssuer returns an issuer based on the properties of acmeIssuer.
+// If acmeIssuer implicitly configures a certain kind of ACMEIssuer (for example,
+// ZeroSSL), the proper wrapper over acmeIssuer will be returned instead.
+func disambiguateACMEIssuer(acmeIssuer *caddytls.ACMEIssuer) certmagic.Issuer {
+	// as a special case, we integrate with ZeroSSL's ACME endpoint if it looks like an
+	// implicit ZeroSSL configuration (this requires a  wrapper type over ACMEIssuer
+	// because of the EAB generation; if EAB is provided, we can use plain ACMEIssuer)
+	if strings.Contains(acmeIssuer.CA, "acme.zerossl.com") && acmeIssuer.ExternalAccount == nil {
+		return &caddytls.ZeroSSLIssuer{ACMEIssuer: acmeIssuer}
+	}
+	return acmeIssuer
+}
+
 // consolidateAutomationPolicies combines automation policies that are the same,
 // for a cleaner overall output.
 func consolidateAutomationPolicies(aps []*caddytls.AutomationPolicy) []*caddytls.AutomationPolicy {

caddytest/integration/caddyfile_adapt/global_options.txt

@@ -56,7 +56,8 @@
 					{
 						"issuer": {
 							"module": "internal"
-						}
+						},
+						"key_type": "ed25519"
 					}
 				],
 				"on_demand": {

caddytest/integration/caddyfile_adapt/global_options_admin.txt

@@ -64,7 +64,8 @@
 					{
 						"issuer": {
 							"module": "internal"
-						}
+						},
+						"key_type": "ed25519"
 					}
 				],
 				"on_demand": {

go.mod

@@ -6,15 +6,15 @@ require (
 	github.com/Masterminds/sprig/v3 v3.1.0
 	github.com/alecthomas/chroma v0.8.0
 	github.com/aryann/difflib v0.0.0-20170710044230-e206f873d14a
-	github.com/caddyserver/certmagic v0.11.3-0.20200808143826-2e100d6d0bcf
+	github.com/caddyserver/certmagic v0.11.3-0.20200810220624-10a8b5c72339
 	github.com/dustin/go-humanize v1.0.1-0.20200219035652-afde56e7acac
 	github.com/go-chi/chi v4.1.2+incompatible
 	github.com/google/cel-go v0.5.1
 	github.com/jsternberg/zap-logfmt v1.2.0
 	github.com/klauspost/compress v1.10.10
 	github.com/klauspost/cpuid v1.2.5
 	github.com/lucas-clemente/quic-go v0.17.3
-	github.com/mholt/acmez v0.1.0
+	github.com/mholt/acmez v0.1.1-0.20200810215816-dbe88fc6cf09
 	github.com/naoina/go-stringutil v0.1.0 // indirect
 	github.com/naoina/toml v0.1.1
 	github.com/smallstep/certificates v0.14.6

go.sum

@@ -86,8 +86,8 @@ github.com/bombsimon/wsl/v2 v2.0.0/go.mod h1:mf25kr/SqFEPhhcxW1+7pxzGlW+hIl/hYTK
 github.com/boombuler/barcode v1.0.0/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bradfitz/go-smtpd v0.0.0-20170404230938-deb6d6237625/go.mod h1:HYsPBTaaSFSlLx/70C2HPIMNZpVV8+vt/A+FMnYP11g=
 github.com/buger/jsonparser v0.0.0-20181115193947-bf1c66bbce23/go.mod h1:bbYlZJ7hK1yFx9hf58LP0zeX7UjIGs20ufpu3evjr+s=
-github.com/caddyserver/certmagic v0.11.3-0.20200808143826-2e100d6d0bcf h1:Srcj7CdiavYImKMLDj8sSJKS3htwwwJB3bjPRTXh+P0=
-github.com/caddyserver/certmagic v0.11.3-0.20200808143826-2e100d6d0bcf/go.mod h1:z0loWzjr6Sr8rOG2pdsiwajDpAcck2wfF8E7hTV0qT4=
+github.com/caddyserver/certmagic v0.11.3-0.20200810220624-10a8b5c72339 h1:wTD+Y63XoBtiTJhe/Xn7WLrwKenmjkt2WxH3FP+Y0DM=
+github.com/caddyserver/certmagic v0.11.3-0.20200810220624-10a8b5c72339/go.mod h1:mqOzOvKa7UcC+TWbBLcP0ZLRut/xaaQBw0hRGWHBIkY=
 github.com/census-instrumentation/opencensus-proto v0.2.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
@@ -384,8 +384,8 @@ github.com/mattn/go-runewidth v0.0.7/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m
 github.com/mattn/go-sqlite3 v1.10.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/mattn/goveralls v0.0.2/go.mod h1:8d1ZMHsd7fW6IRPKQh46F2WRpyib5/X4FOpevwGNQEw=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
-github.com/mholt/acmez v0.1.0 h1:LL7WQVCjZvwbo3pjAUdsqEao5kI8nyHubAGtCzrTS5g=
-github.com/mholt/acmez v0.1.0/go.mod h1:rNLSzYu5VR6ggyarXDKDCNefo06cOkJn+VObTDJCk0U=
+github.com/mholt/acmez v0.1.1-0.20200810215816-dbe88fc6cf09 h1:J7NVJ46iBFeWsUc5aeVv8QNO2mLhI6rJKIbpAsH7d7g=
+github.com/mholt/acmez v0.1.1-0.20200810215816-dbe88fc6cf09/go.mod h1:8qnn8QA/Ewx8E3ZSsmscqsIjhhpxuy9vqdgbX2ceceM=
 github.com/microcosm-cc/bluemonday v1.0.1/go.mod h1:hsXNsILzKxV+sX77C5b8FSuKF00vh2OMYv+xgHpAMF4=
 github.com/miekg/dns v1.1.30 h1:Qww6FseFn8PRfw07jueqIXqodm0JKiiKuK0DeXSqfyo=
 github.com/miekg/dns v1.1.30/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=

modules/caddyhttp/autohttps.go

@@ -451,8 +451,8 @@ func (app *App) createAutomationPolicies(ctx caddy.Context, publicNames, interna
 		if ap.Issuer == nil {
 			ap.Issuer = new(caddytls.ACMEIssuer)
 		}
-		if acmeIssuer, ok := ap.Issuer.(*caddytls.ACMEIssuer); ok {
-			err := app.fillInACMEIssuer(acmeIssuer)
+		if acmeIssuer, ok := ap.Issuer.(acmeCapable); ok {
+			err := app.fillInACMEIssuer(acmeIssuer.GetACMEIssuer())
 			if err != nil {
 				return err
 			}
@@ -470,9 +470,13 @@ func (app *App) createAutomationPolicies(ctx caddy.Context, publicNames, interna
 		basePolicy = new(caddytls.AutomationPolicy)
 	}
 
-	// if the basePolicy has an existing ACMEIssuer, let's
-	// use it, otherwise we'll make one
-	baseACMEIssuer, _ := basePolicy.Issuer.(*caddytls.ACMEIssuer)
+	// if the basePolicy has an existing ACMEIssuer (particularly to
+	// include any type that embeds/wraps an ACMEIssuer), let's use it,
+	// otherwise we'll make one
+	var baseACMEIssuer *caddytls.ACMEIssuer
+	if acmeWrapper, ok := basePolicy.Issuer.(acmeCapable); ok {
+		baseACMEIssuer = acmeWrapper.GetACMEIssuer()
+	}
 	if baseACMEIssuer == nil {
 		// note that this happens if basePolicy.Issuer is nil
 		// OR if it is not nil but is not an ACMEIssuer
@@ -630,3 +634,5 @@ func (app *App) automaticHTTPSPhase2() error {
 	app.allCertDomains = nil // no longer needed; allow GC to deallocate
 	return nil
 }
+
+type acmeCapable interface{ GetACMEIssuer() *caddytls.ACMEIssuer }