add token exchange and iframe option

test/entra-id-saml-bearer.md

@@ -1,4 +1,6 @@
-# OAuth SAML Bearer Assertion Flow
+# Options to embed SAP BTP Applications in Web Applications
+
+## OAuth SAML Bearer Assertion Flow
 
 ```mermaid
 sequenceDiagram
@@ -24,8 +26,70 @@ WebApp->>IdP: Requests SAML Assertion with JWT
 IdP->>WebApp: Provides SAML Assertion
 WebApp->>XSUAA: Requests BTP JWT with SAML Assertion
 XSUAA->>XSUAA: Validates SAML Assertion
-XSUAA->>WebApp: Provides BTS JWT
-WebApp->>BTPApp: Sends request with BTS JWT as Authorization Header
+XSUAA->>WebApp: Provides BTP JWT
+WebApp->>BTPApp: Sends request with BTP JWT as Authorization Header
+BTPApp->>WebApp: Response with Application data
+WebApp->>User: Forward Application Data
+```
+
+## OAuth Token Exchange Flow
+
+```mermaid
+sequenceDiagram
+%% participants
+participant User as User
+participant WebApp as Web Application
+participant IdP as Identity Provider
+participant SAPIAS as SAP Identity Authentication Service
+participant XSUAA as SAP BTP Authentication
+participant BTPApp as SAP BTP Application
+%% arrows
+loop Setup
+WebApp-->>IdP: Trust Configuration
+IdP-->>XSUAA: Trust Configuration
+end
+User->>WebApp: Open App
+WebApp->>IdP: Requests User Authentication
+IdP->>User: Ask User for credentials and other factors
+User->>IdP: Provides credentials and other factors
+IdP->>WebApp: Provides JWT
+WebApp->>User: Session Cookie
+User->>WebApp: Request to SAP
+WebApp->>SAPIAS: Requests BTP JWT with JWT
+SAPIAS->>WebApp: Provides BTP JTW
+WebApp->>BTPApp: Sends request with BTP JWT as Authorization Header
 BTPApp->>WebApp: Response with Application data
 WebApp->>User: Forward Application Data
 ```
+
+## Embed SAP BTP App in Web Application
+
+```mermaid
+sequenceDiagram
+%% participants
+participant User as User
+participant WebApp as Web Application
+participant IdP as Identity Provider
+participant SAPIAS as SAP Identity Authentication Service
+participant XSUAA as SAP BTP Authentication
+participant BTPApp as SAP BTP Application
+%% arrows
+loop Setup
+WebApp-->>IdP: Trust Configuration
+IdP-->>XSUAA: Trust Configuration
+end
+User->>WebApp: Open App
+WebApp->>IdP: Requests User Authentication
+IdP->>User: Ask User for credentials and other factors
+User->>IdP: Provides credentials and other factors
+IdP->>WebApp: Provides JWT
+WebApp->>User: Session Cookie
+User->>WebApp: Request to SAP App
+WebApp->>User: Provides SAP App in a IFrame
+User->>BTPApp: Requests SAP App
+BTPApp->>SAPIAS: Requests User Authentication
+SAPIAS->>IdP: Requests User Authentication
+IdP->>SAPIAS: OpenID Connect
+SAPIAS->>BTPApp: Authenticated User
+BTPApp->>User: Provides SAP App
+```