From 412dcc07d3201561302bc20b6200d893aee69657 Mon Sep 17 00:00:00 2001
From: Matt Holt <mholt@users.noreply.github.com>
Date: Tue, 5 Jul 2022 18:12:25 -0600
Subject: [PATCH] caddytls: Reuse issuer between PreCheck and Issue (#4866)

This enables EAB reuse for ZeroSSLIssuer (which is now supported by ZeroSSL).
---
 modules/caddytls/acmeissuer.go    | 19 +++++++++----------
 modules/caddytls/tls.go           |  2 +-
 modules/caddytls/zerosslissuer.go |  4 ++--
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/modules/caddytls/acmeissuer.go b/modules/caddytls/acmeissuer.go
index 09b31bf1..9552d6f6 100644
--- a/modules/caddytls/acmeissuer.go
+++ b/modules/caddytls/acmeissuer.go
@@ -85,9 +85,11 @@ type ACMEIssuer struct {
 	PreferredChains *ChainPreference `json:"preferred_chains,omitempty"`
 
 	rootPool *x509.CertPool
-	template certmagic.ACMEIssuer
-	magic    *certmagic.Config
 	logger   *zap.Logger
+
+	template certmagic.ACMEIssuer  // set at Provision
+	magic    *certmagic.Config     // set at PreCheck
+	issuer   *certmagic.ACMEIssuer // set at PreCheck; result of template + magic
 }
 
 // CaddyModule returns the Caddy module information.
@@ -217,30 +219,27 @@ func (iss *ACMEIssuer) makeIssuerTemplate() (certmagic.ACMEIssuer, error) {
 // the ConfigSetter interface.
 func (iss *ACMEIssuer) SetConfig(cfg *certmagic.Config) {
 	iss.magic = cfg
+	iss.issuer = certmagic.NewACMEIssuer(cfg, iss.template)
 }
 
-// TODO: I kind of hate how each call to these methods needs to
-// make a new ACME manager to fill in defaults before using; can
-// we find the right place to do that just once and then re-use?
-
 // PreCheck implements the certmagic.PreChecker interface.
 func (iss *ACMEIssuer) PreCheck(ctx context.Context, names []string, interactive bool) error {
-	return certmagic.NewACMEIssuer(iss.magic, iss.template).PreCheck(ctx, names, interactive)
+	return iss.issuer.PreCheck(ctx, names, interactive)
 }
 
 // Issue obtains a certificate for the given csr.
 func (iss *ACMEIssuer) Issue(ctx context.Context, csr *x509.CertificateRequest) (*certmagic.IssuedCertificate, error) {
-	return certmagic.NewACMEIssuer(iss.magic, iss.template).Issue(ctx, csr)
+	return iss.issuer.Issue(ctx, csr)
 }
 
 // IssuerKey returns the unique issuer key for the configured CA endpoint.
 func (iss *ACMEIssuer) IssuerKey() string {
-	return certmagic.NewACMEIssuer(iss.magic, iss.template).IssuerKey()
+	return iss.issuer.IssuerKey()
 }
 
 // Revoke revokes the given certificate.
 func (iss *ACMEIssuer) Revoke(ctx context.Context, cert certmagic.CertificateResource, reason int) error {
-	return certmagic.NewACMEIssuer(iss.magic, iss.template).Revoke(ctx, cert, reason)
+	return iss.issuer.Revoke(ctx, cert, reason)
 }
 
 // GetACMEIssuer returns iss. This is useful when other types embed ACMEIssuer, because
diff --git a/modules/caddytls/tls.go b/modules/caddytls/tls.go
index 9fe30fe3..429b24c9 100644
--- a/modules/caddytls/tls.go
+++ b/modules/caddytls/tls.go
@@ -336,7 +336,7 @@ func (t *TLS) HandleHTTPChallenge(w http.ResponseWriter, r *http.Request) bool {
 	for _, iss := range ap.magic.Issuers {
 		if am, ok := iss.(acmeCapable); ok {
 			iss := am.GetACMEIssuer()
-			if certmagic.NewACMEIssuer(iss.magic, iss.template).HandleHTTPChallenge(w, r) {
+			if iss.issuer.HandleHTTPChallenge(w, r) {
 				return true
 			}
 		}
diff --git a/modules/caddytls/zerosslissuer.go b/modules/caddytls/zerosslissuer.go
index a75063bc..a051ed47 100644
--- a/modules/caddytls/zerosslissuer.go
+++ b/modules/caddytls/zerosslissuer.go
@@ -162,8 +162,8 @@ func (iss *ZeroSSLIssuer) generateEABCredentials(ctx context.Context, acct acme.
 func (iss *ZeroSSLIssuer) initialize() {
 	iss.mu.Lock()
 	defer iss.mu.Unlock()
-	if iss.template.NewAccountFunc == nil {
-		iss.template.NewAccountFunc = iss.newAccountCallback
+	if iss.ACMEIssuer.issuer.NewAccountFunc == nil {
+		iss.ACMEIssuer.issuer.NewAccountFunc = iss.newAccountCallback
 	}
 }