Only allow private keys associated to accounts of an app

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java

@@ -67,6 +67,7 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.security.SignatureException;
 import java.util.Iterator;
+import java.util.Set;
 
 /**
  * This class uses a Builder pattern!
@@ -79,7 +80,7 @@ public class PgpDecryptVerify {
     private ProgressDialogUpdater mProgressDialogUpdater;
     private boolean mAllowSymmetricDecryption;
     private String mPassphrase;
-    private long mEnforcedKeyId;
+    private Set<Long> mAllowedKeyIds;
 
     private PgpDecryptVerify(Builder builder) {
         // private Constructor can only be called from Builder
@@ -90,7 +91,7 @@ public class PgpDecryptVerify {
         this.mProgressDialogUpdater = builder.mProgressDialogUpdater;
         this.mAllowSymmetricDecryption = builder.mAllowSymmetricDecryption;
         this.mPassphrase = builder.mPassphrase;
-        this.mEnforcedKeyId = builder.mEnforcedKeyId;
+        this.mAllowedKeyIds = builder.mAllowedKeyIds;
     }
 
     public static class Builder {
@@ -103,7 +104,7 @@ public class PgpDecryptVerify {
         private ProgressDialogUpdater mProgressDialogUpdater = null;
         private boolean mAllowSymmetricDecryption = true;
         private String mPassphrase = null;
-        private long mEnforcedKeyId = 0;
+        private Set<Long> mAllowedKeyIds = null;
 
         public Builder(Context context, InputData data, OutputStream outStream) {
             this.mContext = context;
@@ -127,14 +128,14 @@ public class PgpDecryptVerify {
         }
 
         /**
-         * Allow this key id alone for decryption.
+         * Allow these key ids alone for decryption.
-         * This means only ciphertexts encrypted for this private key can be decrypted.
+         * This means only ciphertexts encrypted for one of these private key can be decrypted.
          *
-         * @param enforcedKeyId
+         * @param allowedKeyIds
          * @return
          */
-        public Builder enforcedKeyId(long enforcedKeyId) {
+        public Builder allowedKeyIds(Set<Long> allowedKeyIds) {
-            this.mEnforcedKeyId = enforcedKeyId;
+            this.mAllowedKeyIds = allowedKeyIds;
             return this;
         }
 
@@ -236,16 +237,16 @@ public class PgpDecryptVerify {
                     // secret key exists in database
 
                     // allow only a specific key for decryption?
-                    if (mEnforcedKeyId != 0) {
+                    if (mAllowedKeyIds != null) {
                         // TODO: improve this code! get master key directly!
                         PGPSecretKeyRing secretKeyRing =
                                 ProviderHelper.getPGPSecretKeyRingByKeyId(mContext, encData.getKeyID());
                         long masterKeyId = PgpKeyHelper.getMasterKey(secretKeyRing).getKeyID();
                         Log.d(Constants.TAG, "encData.getKeyID():" + encData.getKeyID());
-                        Log.d(Constants.TAG, "enforcedKeyId: " + mEnforcedKeyId);
+                        Log.d(Constants.TAG, "allowedKeyIds: " + mAllowedKeyIds);
                         Log.d(Constants.TAG, "masterKeyId: " + masterKeyId);
 
-                        if (mEnforcedKeyId != masterKeyId) {
+                        if (!mAllowedKeyIds.contains(masterKeyId)) {
                             throw new PgpGeneralException(
                                     mContext.getString(R.string.error_no_secret_key_found));
                         }

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java

@@ -48,6 +48,8 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.HashSet;
+import java.util.Set;
 
 public class ProviderHelper {
 
@@ -867,10 +869,10 @@ public class ProviderHelper {
         return settings;
     }
 
-    public static AccountSettings getApiAccountSettings(Context context, Uri uri) {
+    public static AccountSettings getApiAccountSettings(Context context, Uri accountUri) {
         AccountSettings settings = null;
 
-        Cursor cur = context.getContentResolver().query(uri, null, null, null, null);
+        Cursor cur = context.getContentResolver().query(accountUri, null, null, null, null);
         if (cur != null && cur.moveToFirst()) {
             settings = new AccountSettings();
 
@@ -889,6 +891,20 @@ public class ProviderHelper {
         return settings;
     }
 
+    public static Set<Long> getAllKeyIdsForApp(Context context, Uri uri) {
+        Set<Long> keyIds = new HashSet<Long>();
+
+        Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
+        if (cursor != null) {
+            int keyIdColumn = cursor.getColumnIndex(KeychainContract.ApiAccounts.KEY_ID);
+            while (cursor.moveToNext()) {
+                keyIds.add(cursor.getLong(keyIdColumn));
+            }
+        }
+
+        return keyIds;
+    }
+
     public static byte[] getApiAppSignature(Context context, String packageName) {
         Uri queryUri = ApiApps.buildByPackageNameUri(packageName);
 

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java

@@ -45,6 +45,7 @@ import org.sufficientlysecure.keychain.util.Log;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
+import java.util.Set;
 
 public class OpenPgpService extends RemoteService {
 
@@ -276,7 +277,7 @@ public class OpenPgpService extends RemoteService {
     }
 
     private Intent decryptAndVerifyImpl(Intent data, ParcelFileDescriptor input,
-                                        ParcelFileDescriptor output, AccountSettings accSettings) {
+                                        ParcelFileDescriptor output, Set<Long> allowedKeyIds) {
         try {
             // Get Input- and OutputStream from ParcelFileDescriptor
             InputStream is = new ParcelFileDescriptor.AutoCloseInputStream(input);
@@ -291,7 +292,7 @@ public class OpenPgpService extends RemoteService {
 
                 PgpDecryptVerify.Builder builder = new PgpDecryptVerify.Builder(this, inputData, os);
                 builder.allowSymmetricDecryption(false) // no support for symmetric encryption
-                        .enforcedKeyId(accSettings.getKeyId()) // allow only the private key for this app for decryption
+                        .allowedKeyIds(allowedKeyIds) // allow only private keys associated with accounts of this app
                         .passphrase(passphrase);
 
                 // TODO: currently does not support binary signed-only content
@@ -299,7 +300,7 @@ public class OpenPgpService extends RemoteService {
 
                 if (PgpDecryptVerifyResult.KEY_PASSHRASE_NEEDED == decryptVerifyResult.getStatus()) {
                     // get PendingIntent for passphrase input, add it to given params and return to client
-                    Intent passphraseBundle = getPassphraseBundleIntent(data, accSettings.getKeyId());
+                    Intent passphraseBundle = getPassphraseBundleIntent(data, decryptVerifyResult.getKeyIdPassphraseNeeded());
                     return passphraseBundle;
                 } else if (PgpDecryptVerifyResult.SYMMETRIC_PASSHRASE_NEEDED == decryptVerifyResult.getStatus()) {
                     throw new PgpGeneralException("Decryption of symmetric content not supported by API!");
@@ -452,7 +453,10 @@ public class OpenPgpService extends RemoteService {
             } else if (OpenPgpApi.ACTION_SIGN_AND_ENCRYPT.equals(action)) {
                 return encryptAndSignImpl(data, input, output, accSettings, true);
             } else if (OpenPgpApi.ACTION_DECRYPT_VERIFY.equals(action)) {
-                return decryptAndVerifyImpl(data, input, output, accSettings);
+                String currentPkg = getCurrentCallingPackage();
+                Set<Long> allowedKeyIds =
+                        ProviderHelper.getAllKeyIdsForApp(mContext, KeychainContract.ApiAccounts.buildBaseUri(currentPkg));
+                return decryptAndVerifyImpl(data, input, output, allowedKeyIds);
             } else if (OpenPgpApi.ACTION_GET_KEY.equals(action)) {
                 return getKeyImpl(data);
             } else if (OpenPgpApi.ACTION_GET_KEY_IDS.equals(action)) {

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/remote/RemoteService.java

@@ -127,7 +127,7 @@ public abstract class RemoteService extends Service {
      *
      * @return package name
      */
-    private String getCurrentCallingPackage() {
+    protected String getCurrentCallingPackage() {
         // TODO:
         // callingPackages contains more than one entry when sharedUserId has been used...
         String[] callingPackages = getPackageManager().getPackagesForUid(Binder.getCallingUid());