simplified approach

index.bs

@@ -7669,23 +7669,25 @@ This extension allows for a simple form of transaction authorization. A
 :: A single USVString prompt.
     <xmp class="idl">
     partial dictionary AuthenticationExtensionsClientInputs {
-      USVString txAuthSimple2;
+      USVString txAuthSimple;
     };
     </xmp>
 
 : Client extension processing
-:: If (and only if) the authenticator doesn't support this extension (to be determined by the platform via the response to CTAP getClientInfo), then the Client is expected to display
-    the transaction text to the user and to include the transaction text in the collectedClientData structure as described below.
-    If the authenticator supports this extension, then the client SHALL pass-through the extension to the
-    authenticator and not perform any other client processing.
+:: If this extension is present, the client SHALL
+       1. use a dialog to the user that makes sense in the context of approving a transaction (as opposed to sign in).
+       1. display the transaction text to the user. The client SHOULD
+             indicate that the transaction text originates from a specific relying party
+	     (as opposed to the platform itself).
+
+       1. use the {{CollectedClientTxAuthSimple2Data}} structure containing the transaction text instead of using
+             the {{CollectedClientData}} structure.
+
+       1. pass-through the extension to the authenticator (see "client extension output" below)
+       1. pass-through the "authenticator extension output" to the caller as part of the assertion
 
 
     <div class="issue">
-      Mention that the client shouldn't prompt the user for "sign-in" but instead for approving a transaction.
-
-      Should we always let the client use CollectedClientTxAuthSimple2Data instead of CollectedClientData to have more consistency (or only if the client displayed it)?
-      If yes: Should the client verify it matches the transactionText returned by the authenticator (if that exists)?
-
       Should we keep the "type" on "authenticate" or change to something closer to transaction (SPC uses 'payment.get')?
 
       Should we change the name back to txAuthSimple - cannot really hurt - but makes it easier for authenticators already implementing it.
@@ -7728,7 +7730,7 @@ This extension allows for a simple form of transaction authorization. A
 :: Returns the authenticator extension output string UTF-8 decoded into a USVString.
     <xmp class="idl">
     partial dictionary AuthenticationExtensionsClientOutputs {
-      USVString txAuthSimple2;
+      USVString txAuthSimple;
     };
     </xmp>
 
@@ -7741,11 +7743,12 @@ txAuthSimpleInput = (tstr)
 </pre>
 
 : Authenticator extension processing
-:: The authenticator MUST display the prompt to the user before performing either [=user verification=] or [=test of user
+:: The authenticator MUST display the transaction text to the user
+    before performing either [=user verification=] or [=test of user
     presence=]. The authenticator MAY insert line breaks if needed.
 
 : Authenticator extension output
-:: A single CBOR string, representing the prompt as displayed (including any eventual line breaks).
+:: A single CBOR string, representing the transaction text (excluding any eventual line breaks that were inserted).
 
 <pre>
 CDDL: