From 717cae5c0b4ddc52b68fcf893304ba012f30156e Mon Sep 17 00:00:00 2001
From: Peter Grlica <peter.grlica@gmail.com>
Date: Mon, 10 Jan 2022 10:16:00 +0100
Subject: [PATCH] Added support for SAML HTTP binding

---
 auth/auth.go                 | 2 ++
 auth/saml/saml.go            | 1 +
 auth/saml/sp.go              | 8 ++++++++
 auth/settings/settings.go    | 3 +++
 system/types/app_settings.go | 3 +++
 5 files changed, 17 insertions(+)

diff --git a/auth/auth.go b/auth/auth.go
index 04ab71323..092e638b6 100644
--- a/auth/auth.go
+++ b/auth/auth.go
@@ -300,6 +300,8 @@ func (svc *service) LoadSamlService(ctx context.Context, s *settings.Settings) (
 		SignRequests:    s.Saml.SignRequests,
 		SignatureMethod: s.Saml.SignMethod,
 
+		Binding: s.Saml.Binding,
+
 		IdentityPayload: saml.IdpIdentityPayload{
 			Name:       s.Saml.IDP.IdentName,
 			Handle:     s.Saml.IDP.IdentHandle,
diff --git a/auth/saml/saml.go b/auth/saml/saml.go
index dbb18f199..6722a9c82 100644
--- a/auth/saml/saml.go
+++ b/auth/saml/saml.go
@@ -48,6 +48,7 @@ func UpdateSettings(source *types.AppSettings, dest *settings.Settings) {
 	dest.Saml.Key = saml.Key
 	dest.Saml.SignRequests = saml.SignRequests
 	dest.Saml.SignMethod = saml.SignMethod
+	dest.Saml.Binding = saml.Binding
 
 	dest.Saml.IDP.URL = saml.IDP.URL
 	dest.Saml.IDP.IdentName = saml.IDP.IdentName
diff --git a/auth/saml/sp.go b/auth/saml/sp.go
index 5b4e75a27..b84ac9b77 100644
--- a/auth/saml/sp.go
+++ b/auth/saml/sp.go
@@ -40,6 +40,8 @@ type (
 		SignRequests    bool
 		SignatureMethod string
 
+		Binding string
+
 		// user meta from idp
 		IdentityPayload IdpIdentityPayload
 
@@ -72,6 +74,11 @@ func NewSamlSPService(log *zap.Logger, args SamlSPArgs) (s *SamlSPService, err e
 		sp.SignatureMethod = args.SignatureMethod
 	}
 
+	// default to GET
+	if args.Binding == "" {
+		args.Binding = saml.HTTPRedirectBinding
+	}
+
 	opts := samlsp.Options{
 		URL:         args.Host,
 		Key:         sp.Key,
@@ -88,6 +95,7 @@ func NewSamlSPService(log *zap.Logger, args SamlSPArgs) (s *SamlSPService, err e
 
 	handler.RequestTracker = samlsp.DefaultRequestTracker(opts, &handler.ServiceProvider)
 	handler.ServiceProvider = sp
+	handler.Binding = args.Binding
 
 	s = &SamlSPService{
 		log: log,
diff --git a/auth/settings/settings.go b/auth/settings/settings.go
index 1d20045fb..05fb9db43 100644
--- a/auth/settings/settings.go
+++ b/auth/settings/settings.go
@@ -32,6 +32,9 @@ type (
 		// Signature method for signing
 		SignMethod string
 
+		// Post or redirect binding
+		Binding string
+
 		// Identity provider hostname
 		IDP struct {
 			URL string
diff --git a/system/types/app_settings.go b/system/types/app_settings.go
index c1915b14f..685e9db02 100644
--- a/system/types/app_settings.go
+++ b/system/types/app_settings.go
@@ -107,6 +107,9 @@ type (
 					// Signature method for signing
 					SignMethod string `kv:"sign-method"`
 
+					// Post or redirect binding
+					Binding string `kv:"binding"`
+
 					// Identity provider settings
 					IDP struct {
 						URL string `kv:"url"`