Merge "Identity: Update requirements about SessionTranscript CBOR and provisioning challenge." into rvc-dev
diff --git a/identity/java/android/security/identity/IdentityCredential.java b/identity/java/android/security/identity/IdentityCredential.java
index b351b3d..493c85a 100644
--- a/identity/java/android/security/identity/IdentityCredential.java
+++ b/identity/java/android/security/identity/IdentityCredential.java
@@ -167,25 +167,14 @@
* IntentToRetain = bool
* </pre>
*
- * <p>If the {@code sessionTranscript} parameter is not {@code null}, it must contain CBOR
- * data conforming to the following CDDL schema:
- *
- * <pre>
- * SessionTranscript = [
- * DeviceEngagementBytes,
- * EReaderKeyBytes
- * ]
- *
- * DeviceEngagementBytes = #6.24(bstr .cbor DeviceEngagement) ; Bytes of DeviceEngagement
- * EReaderKeyBytes = #6.24(bstr .cbor EReaderKey.Pub) ; Bytes of EReaderKey.pub
- *
- * EReaderKey.Pub = COSE_Key ; Ephemeral public key provided by reader
- * </pre>
- *
- * <p>where a {@code COSE_Key} structure for the public part of the key-pair previously
- * generated by {@link #createEphemeralKeyPair()} must appear somewhere in
- * {@code DeviceEngagement} and the X and Y coordinates must both be present
- * in uncompressed form.
+ * <p>If the {@code sessionTranscript} parameter is not {@code null}, the X and Y coordinates
+ * of the public part of the key-pair previously generated by {@link #createEphemeralKeyPair()}
+ * must appear somewhere in the bytes of the CBOR. Each of these coordinates must appear
+ * encoded with the most significant bits first and use the exact amount of bits indicated by
+ * the key size of the ephemeral keys. For example, if the ephemeral key is using the P-256
+ * curve then the 32 bytes for the X coordinate encoded with the most significant bits first
+ * must appear somewhere in {@code sessionTranscript} and ditto for the 32 bytes for the Y
+ * coordinate.
*
* <p>If {@code readerAuth} is not {@code null} it must be the bytes of a {@code COSE_Sign1}
* structure as defined in RFC 8152. For the payload nil shall be used and the
diff --git a/identity/java/android/security/identity/WritableIdentityCredential.java b/identity/java/android/security/identity/WritableIdentityCredential.java
index c7aa328..305d0ea 100644
--- a/identity/java/android/security/identity/WritableIdentityCredential.java
+++ b/identity/java/android/security/identity/WritableIdentityCredential.java
@@ -56,10 +56,10 @@
* authority doesn't care about the nature of the security hardware. If called, however, this
* method must be called before {@link #personalize(PersonalizationData)}.
*
- * @param challenge is a byte array whose contents should be unique, fresh and provided by
- * the issuing authority. The value provided is embedded in the attestation
- * extension and enables the issuing authority to verify that the attestation
- * certificate is fresh.
+ * @param challenge is a non-empty byte array whose contents should be unique, fresh and
+ * provided by the issuing authority. The value provided is embedded in the
+ * attestation extension and enables the issuing authority to verify that the
+ * attestation certificate is fresh.
* @return the X.509 certificate for this credential's CredentialKey.
*/
public abstract @NonNull Collection<X509Certificate> getCredentialKeyCertificateChain(