identity: Add support for ECDSA auth and don't require session encryption. am: 55f62fc125

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2241164

Change-Id: I535cc54ea30a8d027c3bd34c93c2f8874c5c5594
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

core/api/current.txt

@@ -37682,6 +37682,7 @@ package android.security.identity {
   public abstract class CredentialDataResult {
     method @Nullable public abstract byte[] getDeviceMac();
     method @NonNull public abstract byte[] getDeviceNameSpaces();
+    method @Nullable public byte[] getDeviceSignature();
     method @NonNull public abstract android.security.identity.CredentialDataResult.Entries getDeviceSignedEntries();
     method @NonNull public abstract android.security.identity.CredentialDataResult.Entries getIssuerSignedEntries();
     method @NonNull public abstract byte[] getStaticAuthenticationData();

identity/java/android/security/identity/CredentialDataResult.java

@@ -105,6 +105,30 @@ public abstract class CredentialDataResult {
      */
     public abstract @Nullable byte[] getDeviceMac();
 
+    /**
+     * Returns a signature over the {@code DeviceAuthenticationBytes} CBOR
+     * specified in {@link #getDeviceNameSpaces()}, to prove to the reader that the data
+     * is from a trusted credential.
+     *
+     * <p>The signature is made using the authentication private key. See section 9.1.3.4 of
+     * ISO/IEC 18013-5:2021 for details of this operation.
+     *
+     * <p>If the session transcript or reader ephemeral key wasn't set on the {@link
+     * PresentationSession} used to obtain this data no signature will be produced and this method
+     * will return {@code null}.
+     *
+     * <p>This is only implemented in feature version 202301 or later. If not implemented, the call
+     * fails with {@link UnsupportedOperationException}. See
+     * {@link android.content.pm.PackageManager#FEATURE_IDENTITY_CREDENTIAL_HARDWARE} for known
+     * feature versions.
+     *
+     * @return A COSE_Sign1 structure as described above or {@code null} if the conditions
+     *     specified above are not met.
+     */
+    public @Nullable byte[] getDeviceSignature() {
+        throw new UnsupportedOperationException();
+    }
+
     /**
      * Returns the static authentication data associated with the dynamic authentication
      * key used to MAC the data returned by {@link #getDeviceNameSpaces()}.

identity/java/android/security/identity/CredstoreCredentialDataResult.java

@@ -46,6 +46,11 @@ class CredstoreCredentialDataResult extends CredentialDataResult {
         return mDeviceSignedResult.getMessageAuthenticationCode();
     }
 
+    @Override
+    public @Nullable byte[] getDeviceSignature() {
+        return mDeviceSignedResult.getSignature();
+    }
+
     @Override
     public @NonNull byte[] getStaticAuthenticationData() {
         return mDeviceSignedResult.getStaticAuthenticationData();

identity/java/android/security/identity/CredstoreIdentityCredential.java

@@ -60,16 +60,19 @@ class CredstoreIdentityCredential extends IdentityCredential {
     private Context mContext;
     private ICredential mBinder;
     private CredstorePresentationSession mSession;
+    private int mFeatureVersion;
 
     CredstoreIdentityCredential(Context context, String credentialName,
             @IdentityCredentialStore.Ciphersuite int cipherSuite,
             ICredential binder,
-            @Nullable CredstorePresentationSession session) {
+            @Nullable CredstorePresentationSession session,
+            int featureVersion) {
         mContext = context;
         mCredentialName = credentialName;
         mCipherSuite = cipherSuite;
         mBinder = binder;
         mSession = session;
+        mFeatureVersion = featureVersion;
     }
 
     private KeyPair mEphemeralKeyPair = null;
@@ -347,12 +350,18 @@ class CredstoreIdentityCredential extends IdentityCredential {
             }
         }
 
+        byte[] signature = resultParcel.signature;
+        if (signature != null && signature.length == 0) {
+            signature = null;
+        }
+
         byte[] mac = resultParcel.mac;
         if (mac != null && mac.length == 0) {
             mac = null;
         }
         CredstoreResultData.Builder resultDataBuilder = new CredstoreResultData.Builder(
-                resultParcel.staticAuthenticationData, resultParcel.deviceNameSpaces, mac);
+                mFeatureVersion, resultParcel.staticAuthenticationData,
+                resultParcel.deviceNameSpaces, mac, signature);
 
         for (ResultNamespaceParcel resultNamespaceParcel : resultParcel.resultNamespaces) {
             for (ResultEntryParcel resultEntryParcel : resultNamespaceParcel.entries) {

identity/java/android/security/identity/CredstoreIdentityCredentialStore.java

@@ -19,6 +19,8 @@ package android.security.identity;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
+import android.content.pm.FeatureInfo;
+import android.content.pm.PackageManager;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.security.GenerateRkpKey;
@@ -30,10 +32,28 @@ class CredstoreIdentityCredentialStore extends IdentityCredentialStore {
 
     private Context mContext = null;
     private ICredentialStore mStore = null;
+    private int mFeatureVersion;
+
+    static int getFeatureVersion(@NonNull Context context) {
+        PackageManager pm = context.getPackageManager();
+        if (pm.hasSystemFeature(PackageManager.FEATURE_IDENTITY_CREDENTIAL_HARDWARE)) {
+            FeatureInfo[] infos = pm.getSystemAvailableFeatures();
+            for (int n = 0; n < infos.length; n++) {
+                FeatureInfo info = infos[n];
+                if (info.name.equals(PackageManager.FEATURE_IDENTITY_CREDENTIAL_HARDWARE)) {
+                    return info.version;
+                }
+            }
+        }
+        // Use of the system feature is not required since Android 12. So for Android 11
+        // return 202009 which is the feature version shipped with Android 11.
+        return 202009;
+    }
 
     private CredstoreIdentityCredentialStore(@NonNull Context context, ICredentialStore store) {
         mContext = context;
         mStore = store;
+        mFeatureVersion = getFeatureVersion(mContext);
     }
 
     static CredstoreIdentityCredentialStore getInstanceForType(@NonNull Context context,
@@ -139,8 +159,7 @@ class CredstoreIdentityCredentialStore extends IdentityCredentialStore {
             ICredential credstoreCredential;
             credstoreCredential = mStore.getCredentialByName(credentialName, cipherSuite);
             return new CredstoreIdentityCredential(mContext, credentialName, cipherSuite,
-                    credstoreCredential,
+                    credstoreCredential, null, mFeatureVersion);
-                    null);
         } catch (android.os.RemoteException e) {
             throw new RuntimeException("Unexpected RemoteException ", e);
         } catch (android.os.ServiceSpecificException e) {
@@ -182,7 +201,8 @@ class CredstoreIdentityCredentialStore extends IdentityCredentialStore {
             throws CipherSuiteNotSupportedException {
         try {
             ISession credstoreSession = mStore.createPresentationSession(cipherSuite);
-            return new CredstorePresentationSession(mContext, cipherSuite, this, credstoreSession);
+            return new CredstorePresentationSession(mContext, cipherSuite, this, credstoreSession,
+                                                    mFeatureVersion);
         } catch (android.os.RemoteException e) {
             throw new RuntimeException("Unexpected RemoteException ", e);
         } catch (android.os.ServiceSpecificException e) {

identity/java/android/security/identity/CredstorePresentationSession.java

@@ -48,15 +48,18 @@ class CredstorePresentationSession extends PresentationSession {
     private byte[] mSessionTranscript = null;
     private boolean mOperationHandleSet = false;
     private long mOperationHandle = 0;
+    private int mFeatureVersion = 0;
 
     CredstorePresentationSession(Context context,
             @IdentityCredentialStore.Ciphersuite int cipherSuite,
             CredstoreIdentityCredentialStore store,
-            ISession binder) {
+            ISession binder,
+            int featureVersion) {
         mContext = context;
         mCipherSuite = cipherSuite;
         mStore = store;
         mBinder = binder;
+        mFeatureVersion = featureVersion;
     }
 
     private void ensureEphemeralKeyPair() {
@@ -147,7 +150,7 @@ class CredstorePresentationSession extends PresentationSession {
                     mBinder.getCredentialForPresentation(credentialName);
                 credential = new CredstoreIdentityCredential(mContext, credentialName,
                                                              mCipherSuite, credstoreCredential,
-                                                             this);
+                                                             this, mFeatureVersion);
                 mCredentialCache.put(credentialName, credential);
 
                 credential.setAllowUsingExhaustedKeys(request.isAllowUsingExhaustedKeys());

identity/java/android/security/identity/CredstoreResultData.java

@@ -30,10 +30,11 @@ import java.util.Map;
  * data requested from a {@link IdentityCredential}.
  */
 class CredstoreResultData extends ResultData {
-
+    int mFeatureVersion = 0;
     byte[] mStaticAuthenticationData = null;
     byte[] mAuthenticatedData = null;
     byte[] mMessageAuthenticationCode = null;
+    byte[] mSignature = null;
 
     private Map<String, Map<String, EntryData>> mData = new LinkedHashMap<>();
 
@@ -60,6 +61,14 @@ class CredstoreResultData extends ResultData {
         return mMessageAuthenticationCode;
     }
 
+    @Override
+    @Nullable byte[] getSignature() {
+        if (mFeatureVersion < 202301) {
+            throw new UnsupportedOperationException();
+        }
+        return mSignature;
+    }
+
     @Override
     public @NonNull byte[] getStaticAuthenticationData() {
         return mStaticAuthenticationData;
@@ -124,13 +133,17 @@ class CredstoreResultData extends ResultData {
     static class Builder {
         private CredstoreResultData mResultData;
 
-        Builder(byte[] staticAuthenticationData,
+        Builder(int featureVersion,
+                byte[] staticAuthenticationData,
                 byte[] authenticatedData,
-                byte[] messageAuthenticationCode) {
+                byte[] messageAuthenticationCode,
+                byte[] signature) {
             this.mResultData = new CredstoreResultData();
+            this.mResultData.mFeatureVersion = featureVersion;
             this.mResultData.mStaticAuthenticationData = staticAuthenticationData;
             this.mResultData.mAuthenticatedData = authenticatedData;
             this.mResultData.mMessageAuthenticationCode = messageAuthenticationCode;
+            this.mResultData.mSignature = signature;
         }
 
         private Map<String, EntryData> getOrCreateInnerMap(String namespaceName) {

identity/java/android/security/identity/IdentityCredential.java

@@ -236,14 +236,15 @@ public abstract class IdentityCredential {
      *   IntentToRetain = bool
      * </pre>
      *
-     * <p>If the {@code sessionTranscript} parameter is not {@code null}, the X and Y coordinates
+     * <p>If mdoc session encryption is used (e.g. if {@link #createEphemeralKeyPair()} has been
-     * of the public part of the key-pair previously generated by {@link #createEphemeralKeyPair()}
+     * called) and if the {@code sessionTranscript} parameter is not {@code null}, the X and Y
-     * must appear somewhere in the bytes of the CBOR. Each of these coordinates must appear
+     * coordinates of the public part of the key-pair previously generated by
-     * encoded with the most significant bits first and use the exact amount of bits indicated by
+     * {@link #createEphemeralKeyPair()} must appear somewhere in the bytes of the CBOR. Each of
-     * the key size of the ephemeral keys. For example, if the ephemeral key is using the P-256
+     * these coordinates must appear encoded with the most significant bits first and use the
-     * curve then the 32 bytes for the X coordinate encoded with the most significant bits first
+     * exact amount of bits indicated by the key size of the ephemeral keys. For example, if the
-     * must appear somewhere in {@code sessionTranscript} and ditto for the 32 bytes for the Y
+     * ephemeral key is using the P-256 curve then the 32 bytes for the X coordinate encoded with
-     * coordinate.
+     * the most significant bits first must appear somewhere in {@code sessionTranscript} and
+     * ditto for the 32 bytes for the Y coordinate.
      *
      * <p>If {@code readerSignature} 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

identity/java/android/security/identity/PresentationSession.java

@@ -73,7 +73,8 @@ public abstract class PresentationSession {
      * <p>If called, this must be called before any calls to
      * {@link #getCredentialData(String, CredentialDataRequest)}.
      *
-     * <p>The X and Y coordinates of the public part of the key-pair returned by {@link
+     * <p>If mdoc session encryption is used (e.g. if {@link #getEphemeralKeyPair()} has been
+     * called) then the X and Y coordinates of the public part of the key-pair returned by {@link
      * #getEphemeralKeyPair()} must appear somewhere in the bytes of the passed in 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

identity/java/android/security/identity/ResultData.java

@@ -134,6 +134,10 @@ public abstract class ResultData {
      */
     public abstract @Nullable byte[] getMessageAuthenticationCode();
 
+    @Nullable byte[] getSignature() {
+        throw new UnsupportedOperationException();
+    }
+
     /**
      * Returns the static authentication data associated with the dynamic authentication
      * key used to sign or MAC the data returned by {@link #getAuthenticatedData()}.