[INJIMOB-3503] - Add details about cross device and same device flow for sd-jwt vp (#2107)

Signed-off-by: swatigoel <meet2swati@gmail.com>

docs/sdjwt-vp-support.md

@@ -2,13 +2,23 @@
 
 This document provides a comprehensive overview of the process for presenting sd-jwt credential to Verifier(relying party), adhering to the OpenId4VP specification.
 
+This feature is applicable for both the flows
+
+- Cross device flow
+  - User scans QR code on wallet app to retrieve authorization request from verifier
+- Same device flow
+  - There are 2 ways to achieve deep link navigation
+    - User opens the verifier on Mobile and clicks on the QR code generated by verifier to retrieve authorization request
+    - User receives authorization request as a link through some notification with custom uri `openid4vp://`. User clicks on link and gets navigated to Wallet App.
+
 ### Actors involved
+
 1. User
 2. Inji Wallet
-3. inji-openid4vp_ (Library for processing OVP request)
+3. inji-openid4vp\_ (Library for processing OVP request)
 4. Verifier (Relying Party)
 
-###  Sequence diagram - Present sd-jwt credential to Verifier (Relying Party)
+### Sequence diagram - Present sd-jwt credential to Verifier (Relying Party)
 
 ```mermaid
 sequenceDiagram
@@ -19,8 +29,8 @@ sequenceDiagram
   participant RP as 🌐 Verifier (Relying Party)
 
   Note over RP: Prepare Authorization Request
-  RP-->>Wallet: Share Authorization Request as QR Code
-  User->>Wallet: Scan QR Code
+  RP-->>Wallet: Share Authorization Request as QR Code or Deep Link
+  User->>Wallet: Scan QR Code or Click on Tap Deep Link
   Wallet->>OVP_Lib: Forward authorization request
   Note over OVP_Lib: Validate authorization request
   OVP_Lib-->>Wallet: Return validated authorization request
@@ -47,46 +57,54 @@ sequenceDiagram
 ```
 
 #### Steps involved
+
 ##### 1. Share Authorization Request as QR Code
+
 The Verifier prepares an authorization request and shares it with the Wallet in the form of a QR code by value or by reference.
 
 ##### 2. Scan QR Code
+
 User scans the QR code using the Wallet application to retrieve the authorization request.
 
 ##### 3. Forward authorization request
+
 The Wallet forwards the scanned authorization request to the _inji-openid4vp_ library for processing and validation.
 
-````
+```
 OpenId4VP.authenticateVerifier(
-    urlEncodedAuthorizationRequest, 
-    trustedVerifiers, 
+    urlEncodedAuthorizationRequest,
+    trustedVerifiers,
     shouldValidateClient
 )
 
 Note:
 - urlEncodedAuthorizationRequest is base64 url encoded authorization request received from Verifier.
 - trustedVerifiers is list of trusted Verifier known to wallet.
-- shouldValidateClient is boolean to indicate whether to validate client or not if client-id-scheme is pre-registered. 
+- shouldValidateClient is boolean to indicate whether to validate client or not if client-id-scheme is pre-registered.
 
-````
+```
 
 ##### 4. Return validated authorization request
+
 The _inji-openid4vp_ library validates the authorization request and returns the validated request to the Wallet.
 
 ##### 5. Display matching credentials to user for selection
-The Wallet processes the authorization request and filters the credentials that match the requested claims. 
+
+The Wallet processes the authorization request and filters the credentials that match the requested claims.
 It then displays these matching credentials to the user for selection.
 
 ##### 6. User selects credential(s)
+
 The user selects one or more credentials from the displayed list in the Wallet application.
 
 ##### 7. Pass user's selected credentials after face verification if needed
+
 If any of the selected VCs has face/picture, the wallet asks user to perform face verification before passing the selected credentials to the _inji-openid4vp_ library.
 
-````
+```
 OpenId4VP.constructUnsignedVPToken(
-    selectedVCs, 
-    holderId, 
+    selectedVCs,
+    holderId,
     signatureAlgorithm
 )
 
@@ -96,26 +114,28 @@ Note:
 - signatureSuite is signature algorithm to be used for signing VP Token. This is needed for ldp_vc format only. It's JsonWebSignature2020 as we are supporting only Ed25519Signature2020
   - For the SD-JWT format,, this field is ignored because the signature algorithm is determined from the `cnf` claim
 
-````
+```
 
 ##### 8. Check if Holder key binding possible and prepare VP token
+
 The _inji-openid4vp_ library validates the selected credentials and check if key binding possible or not.
 If `cnf` claim exists, it is considered that key binding is possible, otherwise not possible.
 
-
 ##### 9. Prepare key binding details for signing
+
 The _inji-openid4vp_ library creates the unsigned VP Token data and prepares the key binding details for signing.
 
 ##### 10. Return header and payload to create signature for Key binding
+
 The _inji-openid4vp_ library returns header and payload as unsignedVPToken to create signature.
 
-````
+```
 It returns a map of credential format and unsigned VP Token data to the Wallet to create signature
 
-for vc+sd-jwt and dc+sd-jwt format 
+for vc+sd-jwt and dc+sd-jwt format
 {
     "vc+sd-jwt": {
-        "uuid": "<header>.<payload>" 
+        "uuid": "<header>.<payload>"
     },
     "dc+sd-jwt": {
        "uuid": "<header>.<payload>"
@@ -125,41 +145,48 @@ for vc+sd-jwt and dc+sd-jwt format
 Note:
 - It returns header and payload to create signature for Key binding.
   - uuid is being used to map the signature returned from wallet to the respective sd-jwt vc
-````
+```
 
 ##### 11. Create signature for Key binding
+
 The Wallet creates a signature for key binding using the provided header and payload for each sd-jwt format credential.
 It extracts `alg` from the provided header and use that algorithm to create signature.
 
-
 ##### 12. Share signature for Key binding
+
 The wallet shares key binding signature with the _inji-openid4vp_ library.
 
 ##### 13. Attach signature to VP Token
+
 The _inji-openid4vp_ library attaches the signature to already created unsigned vp token.
 
 ##### 14. Submit VP Token with key binding
+
 The _inji-openid4vp_ library submits the VP Token with key binding to the Verifier(relying party) as per Authorization request response mode.
 
 ##### 15. Prepare VP Token without key binding
+
 The _inji-openid4vp_ library create vp token without key binding details.
 
 ##### 16. Indicate no key binding required
+
 The _inji-openid4vp_ library creates the unsigned VP Token data without key binding details.
 
-````
+```
 It returns a empty map of credential format because key binding is not required.
 
-for vc+sd-jwt and dc+sd-jwt format 
+for vc+sd-jwt and dc+sd-jwt format
 {
     "vc+sd-jwt": {},
     "dc+sd-jwt": {}
 }
 
-````
+```
 
 ##### 17. Return the data without signature
+
 The wallet does not create the signature and return the data as is.
 
 ##### 18. Submit VP Token without key binding
-The _inji-openid4vp_ library submits the VP Token without key binding to the Verifier(relying party) as per Authorization request response mode.
+
+The _inji-openid4vp_ library submits the VP Token without key binding to the Verifier(relying party) as per Authorization request response mode.