Merge pull request #14563 from tdabasinskas/broken_oauth_provider

Support OAuth providers that are not RFC6749 compliant

conf/defaults.ini

@@ -335,6 +335,7 @@ tls_skip_verify_insecure = false
 tls_client_cert =
 tls_client_key =
 tls_client_ca =
+send_client_credentials_via_post = false
 
 #################################### Basic Auth ##########################
 [auth.basic]

conf/sample.ini

@@ -284,6 +284,10 @@ log_queries =
 ;tls_client_key =
 ;tls_client_ca =
 
+; Set to true to enable sending client_id and client_secret via POST body instead of Basic authentication HTTP header
+; This might be required if the OAuth provider is not RFC6749 compliant, only supporting credentials passed via POST payload
+;send_client_credentials_via_post = false
+
 #################################### Grafana.com Auth ####################
 [auth.grafana_com]
 ;enabled = false

docs/sources/auth/generic-oauth.md

@@ -17,7 +17,7 @@ can find examples using Okta, BitBucket, OneLogin and Azure.
 
 This callback URL must match the full HTTP address that you use in your browser to access Grafana, but with the prefix path of `/login/generic_oauth`.
 
-You may have to set the `root_url` option of `[server]` for the callback URL to be 
+You may have to set the `root_url` option of `[server]` for the callback URL to be
 correct. For example in case you are serving Grafana behind a proxy.
 
 Example config:
@@ -209,6 +209,17 @@ allowed_organizations =
     token_url = https://<your domain>.my.centrify.com/OAuth2/Token/<Application ID>
     ```
 
+## Set up OAuth2 with non-compliant providers
+
+Some OAuth2 providers might not support `client_id` and `client_secret` passed via Basic Authentication HTTP header, which
+results in `invalid_client` error. To allow Grafana to authenticate via these type of providers, the client identifiers must be
+send via POST body, which can be enabled via the following settings:
+
+    ```bash
+    [auth.generic_oauth]
+    send_client_credentials_via_post = true
+    ```
+
 <hr>
 
 

pkg/setting/setting_oauth.go

 package setting
 
 type OAuthInfo struct {
-	ClientId, ClientSecret string
-	Scopes                 []string
-	AuthUrl, TokenUrl      string
-	Enabled                bool
-	EmailAttributeName     string
-	AllowedDomains         []string
-	HostedDomain           string
-	ApiUrl                 string
-	AllowSignup            bool
-	Name                   string
-	TlsClientCert          string
-	TlsClientKey           string
-	TlsClientCa            string
-	TlsSkipVerify          bool
+	ClientId, ClientSecret       string
+	Scopes                       []string
+	AuthUrl, TokenUrl            string
+	Enabled                      bool
+	EmailAttributeName           string
+	AllowedDomains               []string
+	HostedDomain                 string
+	ApiUrl                       string
+	AllowSignup                  bool
+	Name                         string
+	TlsClientCert                string
+	TlsClientKey                 string
+	TlsClientCa                  string
+	TlsSkipVerify                bool
+	SendClientCredentialsViaPost bool
 }
 
 type OAuther struct {

pkg/social/social.go

@@ -63,28 +63,34 @@ func NewOAuthService() {
 	for _, name := range allOauthes {
 		sec := setting.Raw.Section("auth." + name)
 		info := &setting.OAuthInfo{
-			ClientId:           sec.Key("client_id").String(),
-			ClientSecret:       sec.Key("client_secret").String(),
-			Scopes:             util.SplitString(sec.Key("scopes").String()),
-			AuthUrl:            sec.Key("auth_url").String(),
-			TokenUrl:           sec.Key("token_url").String(),
-			ApiUrl:             sec.Key("api_url").String(),
-			Enabled:            sec.Key("enabled").MustBool(),
-			EmailAttributeName: sec.Key("email_attribute_name").String(),
-			AllowedDomains:     util.SplitString(sec.Key("allowed_domains").String()),
-			HostedDomain:       sec.Key("hosted_domain").String(),
-			AllowSignup:        sec.Key("allow_sign_up").MustBool(),
-			Name:               sec.Key("name").MustString(name),
-			TlsClientCert:      sec.Key("tls_client_cert").String(),
-			TlsClientKey:       sec.Key("tls_client_key").String(),
-			TlsClientCa:        sec.Key("tls_client_ca").String(),
-			TlsSkipVerify:      sec.Key("tls_skip_verify_insecure").MustBool(),
+			ClientId:                     sec.Key("client_id").String(),
+			ClientSecret:                 sec.Key("client_secret").String(),
+			Scopes:                       util.SplitString(sec.Key("scopes").String()),
+			AuthUrl:                      sec.Key("auth_url").String(),
+			TokenUrl:                     sec.Key("token_url").String(),
+			ApiUrl:                       sec.Key("api_url").String(),
+			Enabled:                      sec.Key("enabled").MustBool(),
+			EmailAttributeName:           sec.Key("email_attribute_name").String(),
+			AllowedDomains:               util.SplitString(sec.Key("allowed_domains").String()),
+			HostedDomain:                 sec.Key("hosted_domain").String(),
+			AllowSignup:                  sec.Key("allow_sign_up").MustBool(),
+			Name:                         sec.Key("name").MustString(name),
+			TlsClientCert:                sec.Key("tls_client_cert").String(),
+			TlsClientKey:                 sec.Key("tls_client_key").String(),
+			TlsClientCa:                  sec.Key("tls_client_ca").String(),
+			TlsSkipVerify:                sec.Key("tls_skip_verify_insecure").MustBool(),
+			SendClientCredentialsViaPost: sec.Key("send_client_credentials_via_post").MustBool(),
 		}
 
 		if !info.Enabled {
 			continue
 		}
 
+		// handle the clients that do not properly support Basic auth headers and require passing client_id/client_secret via POST payload
+		if info.SendClientCredentialsViaPost {
+			oauth2.RegisterBrokenAuthHeaderProvider(info.TokenUrl)
+		}
+
 		if name == "grafananet" {
 			name = grafanaCom
 		}