revise description of RSA cred public key encoding in attestation data.

fixes #240

index.bs

@@ -1294,17 +1294,14 @@ authenticator MUST first generate an <a>authenticatorData</a> structure, with th
                 format (see [[!SEC1]] Section 2.3.3). The authentication signature scheme is ECDSA using keys on curve P-256 and
                 the SHA-256 hash algorithm. 
 
-            2. 0x0102.  RSA public key [[!PKCS1v2.2]]. 
+            2. 0x0102.  RSA public key in DER encoding of the RSAPublicKey object as given in section A.1 of [[!PKCS1v2.2]].
                 The authentication signature scheme is either RSASSA-PKCS1-v1_5 or RSASSA-PSS.
 
-                In the case of RSASSA-PSS, the default
+                When RSASSA-PSS is used as the authentication signature scheme, the default
                 parameters according to [[!RFC4055]] MUST be assumed, i.e.,
                 - Mask Generation Algorithm MGF1 with SHA256
                 - Salt Length of 32 bytes, i.e., the length of a SHA256 hash value.
                 - Trailer Field value of 1, which represents the trailer field with hexadecimal value `0xBC`.
-
-                That is, `[modulus (256 bytes), e (m-n bytes)]`, where `m` is the total length of the field. This total length
-                should be taken from the object containing this key
         </td>
     </tr>
     <tr>