performance: avoid expensive getSecretKeyType call, use cached where possible

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/CertifyOperation.java

@@ -38,6 +38,7 @@ import org.sufficientlysecure.keychain.pgp.PgpCertifyOperation.PgpCertifyResult;
 import org.sufficientlysecure.keychain.pgp.Progressable;
 import org.sufficientlysecure.keychain.pgp.UncachedKeyRing;
 import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
+import org.sufficientlysecure.keychain.provider.CachedPublicKeyRing;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.provider.ProviderHelper.NotFoundException;
 import org.sufficientlysecure.keychain.service.CertifyActionsParcel;
@@ -75,24 +76,22 @@ public class CertifyOperation extends BaseOperation<CertifyActionsParcel> {
 
         // Retrieve and unlock secret key
         CanonicalizedSecretKey certificationKey;
+        long masterKeyId = parcel.mMasterKeyId;
         try {
 
             log.add(LogType.MSG_CRT_MASTER_FETCH, 1);
-            CanonicalizedSecretKeyRing secretKeyRing =
-                    mProviderHelper.getCanonicalizedSecretKeyRing(parcel.mMasterKeyId);
-            log.add(LogType.MSG_CRT_UNLOCK, 1);
-            certificationKey = secretKeyRing.getSecretKey();
 
+            CachedPublicKeyRing cachedPublicKeyRing = mProviderHelper.getCachedPublicKeyRing(masterKeyId);
             Passphrase passphrase;
 
-            switch (certificationKey.getSecretKeyType()) {
+            switch (cachedPublicKeyRing.getSecretKeyType(masterKeyId)) {
                 case PIN:
                 case PATTERN:
                 case PASSPHRASE:
                     passphrase = cryptoInput.getPassphrase();
                     if (passphrase == null) {
                         try {
-                            passphrase = getCachedPassphrase(certificationKey.getKeyId(), certificationKey.getKeyId());
+                            passphrase = getCachedPassphrase(masterKeyId, masterKeyId);
                         } catch (PassphraseCacheInterface.NoSecretKeyException ignored) {
                             // treat as a cache miss for error handling purposes
                         }
@@ -100,10 +99,7 @@ public class CertifyOperation extends BaseOperation<CertifyActionsParcel> {
 
                     if (passphrase == null) {
                         return new CertifyResult(log,
-                                RequiredInputParcel.createRequiredSignPassphrase(
+                                RequiredInputParcel.createRequiredSignPassphrase(masterKeyId, masterKeyId, null),
-                                        certificationKey.getKeyId(),
-                                        certificationKey.getKeyId(),
-                                        null),
                                 cryptoInput
                         );
                     }
@@ -123,7 +119,14 @@ public class CertifyOperation extends BaseOperation<CertifyActionsParcel> {
                     return new CertifyResult(CertifyResult.RESULT_ERROR, log);
             }
 
-            if (!certificationKey.unlock(passphrase)) {
+            // Get actual secret key
+            CanonicalizedSecretKeyRing secretKeyRing =
+                    mProviderHelper.getCanonicalizedSecretKeyRing(parcel.mMasterKeyId);
+            certificationKey = secretKeyRing.getSecretKey();
+
+            log.add(LogType.MSG_CRT_UNLOCK, 1);
+            boolean unlockSuccessful = certificationKey.unlock(passphrase);
+            if (!unlockSuccessful) {
                 log.add(LogType.MSG_CRT_ERROR_UNLOCK, 2);
                 return new CertifyResult(CertifyResult.RESULT_ERROR, log);
             }
@@ -142,8 +145,7 @@ public class CertifyOperation extends BaseOperation<CertifyActionsParcel> {
         int certifyOk = 0, certifyError = 0, uploadOk = 0, uploadError = 0;
 
         NfcSignOperationsBuilder allRequiredInput = new NfcSignOperationsBuilder(
-                cryptoInput.getSignatureTime(), certificationKey.getKeyId(),
+                cryptoInput.getSignatureTime(), masterKeyId, masterKeyId);
-                certificationKey.getKeyId());
 
         // Work through all requested certifications
         for (CertifyAction action : parcel.mCertifyActions) {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/CanonicalizedSecretKey.java

@@ -120,7 +120,9 @@ public class CanonicalizedSecretKey extends CanonicalizedPublicKey {
 
     }
 
-    public SecretKeyType getSecretKeyType() {
+    // This method can potentially take a LONG time (i.e. seconds), so it should only
+    // ever be called by ProviderHelper to be cached in the database.
+    public SecretKeyType getSecretKeyTypeSuperExpensive() {
         S2K s2k = mSecretKey.getS2K();
         if (s2k != null && s2k.getType() == S2K.GNU_DUMMY_S2K) {
             // divert to card is special

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/CanonicalizedSecretKeyRing.java

@@ -70,20 +70,6 @@ public class CanonicalizedSecretKeyRing extends CanonicalizedKeyRing {
         return new CanonicalizedSecretKey(this, mRing.getSecretKey(id));
     }
 
-    /** Returns the key id which should be used for signing.
-     *
-     * This method returns keys which are actually available (ie. secret available, and not stripped,
-     * revoked, or expired), hence only works on keyrings where a secret key is available!
-     */
-    public long getSecretSignId() throws PgpGeneralException {
-        for(CanonicalizedSecretKey key : secretKeyIterator()) {
-            if (key.canSign() && key.isValid() && key.getSecretKeyType().isUsable()) {
-                return key.getKeyId();
-            }
-        }
-        throw new PgpGeneralException("no valid signing key available");
-    }
-
     public IterableIterator<CanonicalizedSecretKey> secretKeyIterator() {
         final Iterator<PGPSecretKey> it = mRing.getSecretKeys();
         return new IterableIterator<>(new Iterator<CanonicalizedSecretKey>() {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerifyOperation.java

@@ -64,6 +64,8 @@ import org.sufficientlysecure.keychain.operations.results.OperationResult.LogTyp
 import org.sufficientlysecure.keychain.operations.results.OperationResult.OperationLog;
 import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey.SecretKeyType;
 import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
+import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException;
+import org.sufficientlysecure.keychain.provider.CachedPublicKeyRing;
 import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRings;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.service.input.CryptoInputParcel;
@@ -539,7 +541,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
 
         PGPPublicKeyEncryptedData encryptedDataAsymmetric = null;
         PGPPBEEncryptedData encryptedDataSymmetric = null;
-        CanonicalizedSecretKey secretEncryptionKey = null;
+        CanonicalizedSecretKey decryptionKey = null;
 
         Passphrase passphrase = null;
 
@@ -560,87 +562,89 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
                 log.add(LogType.MSG_DC_ASYM, indent,
                         KeyFormattingUtils.convertKeyIdToHex(subKeyId));
 
-                CanonicalizedSecretKeyRing secretKeyRing;
+                CachedPublicKeyRing cachedPublicKeyRing;
                 try {
                     // get actual keyring object based on master key id
-                    secretKeyRing = mProviderHelper.getCanonicalizedSecretKeyRing(
+                    cachedPublicKeyRing = mProviderHelper.getCachedPublicKeyRing(
                             KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(subKeyId)
                     );
-                } catch (ProviderHelper.NotFoundException e) {
+                    long masterKeyId = cachedPublicKeyRing.getMasterKeyId();
+
+                    // allow only specific keys for decryption?
+                    if (input.getAllowedKeyIds() != null) {
+                        Log.d(Constants.TAG, "encData.getKeyID(): " + subKeyId);
+                        Log.d(Constants.TAG, "mAllowedKeyIds: " + input.getAllowedKeyIds());
+                        Log.d(Constants.TAG, "masterKeyId: " + masterKeyId);
+
+                        if (!input.getAllowedKeyIds().contains(masterKeyId)) {
+                            // this key is in our db, but NOT allowed!
+                            // continue with the next packet in the while loop
+                            result.skippedDisallowedKey = true;
+                            log.add(LogType.MSG_DC_ASKIP_NOT_ALLOWED, indent + 1);
+                            continue;
+                        }
+                    }
+
+                    SecretKeyType secretKeyType = cachedPublicKeyRing.getSecretKeyType(subKeyId);
+                    if (!secretKeyType.isUsable()) {
+                        decryptionKey = null;
+                        log.add(LogType.MSG_DC_ASKIP_UNAVAILABLE, indent + 1);
+                        continue;
+                    }
+
+                    // get actual subkey which has been used for this encryption packet
+                    CanonicalizedSecretKeyRing canonicalizedSecretKeyRing = mProviderHelper
+                            .getCanonicalizedSecretKeyRing(masterKeyId);
+                    CanonicalizedSecretKey candidateDecryptionKey = canonicalizedSecretKeyRing.getSecretKey(subKeyId);
+
+                    if (!candidateDecryptionKey.canEncrypt()) {
+                        log.add(LogType.MSG_DC_ASKIP_BAD_FLAGS, indent + 1);
+                        continue;
+                    }
+
+                    if (secretKeyType == SecretKeyType.DIVERT_TO_CARD) {
+                        passphrase = null;
+                    } else if (secretKeyType == SecretKeyType.PASSPHRASE_EMPTY) {
+                        passphrase = new Passphrase("");
+                    } else if (cryptoInput.hasPassphrase()) {
+                        passphrase = cryptoInput.getPassphrase();
+                    } else {
+                        // if no passphrase was explicitly set try to get it from the cache service
+                        try {
+                            // returns "" if key has no passphrase
+                            passphrase = getCachedPassphrase(subKeyId);
+                            log.add(LogType.MSG_DC_PASS_CACHED, indent + 1);
+                        } catch (PassphraseCacheInterface.NoSecretKeyException e) {
+                            log.add(LogType.MSG_DC_ERROR_NO_KEY, indent + 1);
+                            return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log));
+                        }
+
+                        // if passphrase was not cached, return here indicating that a passphrase is missing!
+                        if (passphrase == null) {
+                            log.add(LogType.MSG_DC_PENDING_PASSPHRASE, indent + 1);
+                            return result.with(new DecryptVerifyResult(log,
+                                    RequiredInputParcel.createRequiredDecryptPassphrase(masterKeyId, subKeyId),
+                                    cryptoInput));
+                        }
+                    }
+
+                    // check for insecure encryption key
+                    if ( ! PgpSecurityConstants.isSecureKey(candidateDecryptionKey)) {
+                        log.add(LogType.MSG_DC_INSECURE_KEY, indent + 1);
+                        result.insecureEncryptionKey = true;
+                    }
+
+                    // we're good, write down the data for later
+                    asymmetricPacketFound = true;
+                    encryptedDataAsymmetric = encData;
+                    decryptionKey = candidateDecryptionKey;
+
+                } catch (PgpKeyNotFoundException | ProviderHelper.NotFoundException e) {
                     // continue with the next packet in the while loop
                     log.add(LogType.MSG_DC_ASKIP_NO_KEY, indent + 1);
                     continue;
                 }
 
-                // allow only specific keys for decryption?
-                if (input.getAllowedKeyIds() != null) {
-                    long masterKeyId = secretKeyRing.getMasterKeyId();
-                    Log.d(Constants.TAG, "encData.getKeyID(): " + subKeyId);
-                    Log.d(Constants.TAG, "mAllowedKeyIds: " + input.getAllowedKeyIds());
-                    Log.d(Constants.TAG, "masterKeyId: " + masterKeyId);
-
-                    if (!input.getAllowedKeyIds().contains(masterKeyId)) {
-                        // this key is in our db, but NOT allowed!
-                        // continue with the next packet in the while loop
-                        result.skippedDisallowedKey = true;
-                        log.add(LogType.MSG_DC_ASKIP_NOT_ALLOWED, indent + 1);
-                        continue;
-                    }
-                }
-
-                // get subkey which has been used for this encryption packet
-                secretEncryptionKey = secretKeyRing.getSecretKey(subKeyId);
-
-                if (!secretEncryptionKey.canEncrypt()) {
-                    secretEncryptionKey = null;
-                    log.add(LogType.MSG_DC_ASKIP_BAD_FLAGS, indent + 1);
-                    continue;
-                }
-
-                if (!secretEncryptionKey.getSecretKeyType().isUsable()) {
-                    secretEncryptionKey = null;
-                    log.add(LogType.MSG_DC_ASKIP_UNAVAILABLE, indent + 1);
-                    continue;
-                }
-
-                /* secret key exists in database and is allowed! */
-                asymmetricPacketFound = true;
-
-                encryptedDataAsymmetric = encData;
-
-                if (secretEncryptionKey.getSecretKeyType() == SecretKeyType.DIVERT_TO_CARD) {
-                    passphrase = null;
-                } else if (secretKeyType == SecretKeyType.PASSPHRASE_EMPTY) {
-                    passphrase = new Passphrase("");
-                } else if (cryptoInput.hasPassphrase()) {
-                    passphrase = cryptoInput.getPassphrase();
-                } else {
-                    // if no passphrase was explicitly set try to get it from the cache service
-                    try {
-                        // returns "" if key has no passphrase
-                        passphrase = getCachedPassphrase(subKeyId);
-                        log.add(LogType.MSG_DC_PASS_CACHED, indent + 1);
-                    } catch (PassphraseCacheInterface.NoSecretKeyException e) {
-                        log.add(LogType.MSG_DC_ERROR_NO_KEY, indent + 1);
-                        return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log));
-                    }
-
-                    // if passphrase was not cached, return here indicating that a passphrase is missing!
-                    if (passphrase == null) {
-                        log.add(LogType.MSG_DC_PENDING_PASSPHRASE, indent + 1);
-                        return result.with(new DecryptVerifyResult(log,
-                                RequiredInputParcel.createRequiredDecryptPassphrase(
-                                        secretKeyRing.getMasterKeyId(), secretEncryptionKey.getKeyId()),
-                                cryptoInput));
-                    }
-                }
-
-                // check for insecure encryption key
-                if ( ! PgpSecurityConstants.isSecureKey(secretEncryptionKey)) {
-                    log.add(LogType.MSG_DC_INSECURE_KEY, indent + 1);
-                    result.insecureEncryptionKey = true;
-                }
-
                 // break out of while, only decrypt the first packet where we have a key
                 break;
 
@@ -737,7 +741,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
 
             try {
                 log.add(LogType.MSG_DC_UNLOCKING, indent + 1);
-                if (!secretEncryptionKey.unlock(passphrase)) {
+                if (!decryptionKey.unlock(passphrase)) {
                     log.add(LogType.MSG_DC_ERROR_BAD_PASSPHRASE, indent + 1);
                     return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log));
                 }
@@ -750,7 +754,7 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
             updateProgress(R.string.progress_preparing_streams, currentProgress, 100);
 
             CachingDataDecryptorFactory decryptorFactory
-                    = secretEncryptionKey.getCachingDecryptorFactory(cryptoInput);
+                    = decryptionKey.getCachingDecryptorFactory(cryptoInput);
 
             // special case: if the decryptor does not have a session key cached for this encrypted
             // data, and can't actually decrypt on its own, return a pending intent
@@ -759,8 +763,8 @@ public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInp
 
                 log.add(LogType.MSG_DC_PENDING_NFC, indent + 1);
                 return result.with(new DecryptVerifyResult(log, RequiredInputParcel.createNfcDecryptOperation(
-                        secretEncryptionKey.getRing().getMasterKeyId(),
+                        decryptionKey.getRing().getMasterKeyId(),
-                        secretEncryptionKey.getKeyId(), encryptedDataAsymmetric.getSessionKey()[0]
+                        decryptionKey.getKeyId(), encryptedDataAsymmetric.getSessionKey()[0]
                 ), cryptoInput));
 
             }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncryptOperation.java

@@ -166,12 +166,13 @@ public class PgpSignEncryptOperation extends BaseOperation {
             updateProgress(R.string.progress_extracting_signature_key, 0, 100);
 
             try {
-                // fetch the indicated master key id (the one whose name we sign in)
+                long signingMasterKeyId = input.getSignatureMasterKeyId();
-                CanonicalizedSecretKeyRing signingKeyRing =
+                long signingSubKeyId = input.getSignatureSubKeyId();
-                        mProviderHelper.getCanonicalizedSecretKeyRing(input.getSignatureMasterKeyId());
+                {
-
+                    CanonicalizedSecretKeyRing signingKeyRing =
-                // fetch the specific subkey to sign with, or just use the master key if none specified
+                            mProviderHelper.getCanonicalizedSecretKeyRing(signingMasterKeyId);
-                signingKey = signingKeyRing.getSecretKey(input.getSignatureSubKeyId());
+                    signingKey = signingKeyRing.getSecretKey(input.getSignatureSubKeyId());
+                }
 
                 // Make sure we are allowed to sign here!
                 if (!signingKey.canSign()) {
@@ -179,7 +180,7 @@ public class PgpSignEncryptOperation extends BaseOperation {
                     return new PgpSignEncryptResult(PgpSignEncryptResult.RESULT_ERROR, log);
                 }
 
-                switch (signingKey.getSecretKeyType()) {
+                switch (mProviderHelper.getCachedPublicKeyRing(signingMasterKeyId).getSecretKeyType(signingSubKeyId)) {
                     case DIVERT_TO_CARD:
                     case PASSPHRASE_EMPTY: {
                         if (!signingKey.unlock(new Passphrase())) {
@@ -196,14 +197,14 @@ public class PgpSignEncryptOperation extends BaseOperation {
                         Passphrase localPassphrase = cryptoInput.getPassphrase();
                         if (localPassphrase == null) {
                             try {
-                                localPassphrase = getCachedPassphrase(signingKeyRing.getMasterKeyId(), signingKey.getKeyId());
+                                localPassphrase = getCachedPassphrase(signingMasterKeyId, signingKey.getKeyId());
                             } catch (PassphraseCacheInterface.NoSecretKeyException ignored) {
                             }
                         }
                         if (localPassphrase == null) {
                             log.add(LogType.MSG_PSE_PENDING_PASSPHRASE, indent + 1);
                             return new PgpSignEncryptResult(log, RequiredInputParcel.createRequiredSignPassphrase(
-                                    signingKeyRing.getMasterKeyId(), signingKey.getKeyId(),
+                                    signingMasterKeyId, signingKey.getKeyId(),
                                     cryptoInput.getSignatureTime()), cryptoInput);
                         }
                         if (!signingKey.unlock(localPassphrase)) {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/CachedPublicKeyRing.java

@@ -74,7 +74,7 @@ public class CachedPublicKeyRing extends KeyRing {
     public long extractOrGetMasterKeyId() throws PgpKeyNotFoundException {
         // try extracting from the uri first
         String firstSegment = mUri.getPathSegments().get(1);
-        if (!firstSegment.equals("find")) try {
+        if (!"find".equals(firstSegment)) try {
             return Long.parseLong(firstSegment);
         } catch (NumberFormatException e) {
             // didn't work? oh well.

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java

@@ -34,6 +34,7 @@ import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.operations.results.ImportKeyResult;
 import org.sufficientlysecure.keychain.pgp.WrappedUserAttribute;
+import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException;
 import org.sufficientlysecure.keychain.provider.KeychainContract.UserPackets;
 import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;
 import org.sufficientlysecure.keychain.util.ParcelableFileCache.IteratorWithSize;
@@ -254,8 +255,9 @@ public class ProviderHelper {
                 KeyRings.MASTER_KEY_ID, FIELD_TYPE_INTEGER);
     }
 
-    public CachedPublicKeyRing getCachedPublicKeyRing(Uri queryUri) {
+    public CachedPublicKeyRing getCachedPublicKeyRing(Uri queryUri) throws PgpKeyNotFoundException {
-        return new CachedPublicKeyRing(this, queryUri);
+        long masterKeyId = new CachedPublicKeyRing(this, queryUri).extractOrGetMasterKeyId();
+        return getCachedPublicKeyRing(masterKeyId);
     }
 
     public CachedPublicKeyRing getCachedPublicKeyRing(long id) {
@@ -828,7 +830,7 @@ public class ProviderHelper {
                 mIndent += 1;
                 for (CanonicalizedSecretKey sub : keyRing.secretKeyIterator()) {
                     long id = sub.getKeyId();
-                    SecretKeyType mode = sub.getSecretKeyType();
+                    SecretKeyType mode = sub.getSecretKeyTypeSuperExpensive();
                     values.put(Keys.HAS_SECRET, mode.getNum());
                     int upd = mContentResolver.update(uri, values, Keys.KEY_ID + " = ?",
                             new String[]{Long.toString(id)});

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/PassphraseDialogActivity.java

@@ -54,6 +54,7 @@ import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKeyRing;
 import org.sufficientlysecure.keychain.pgp.KeyRing;
 import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
 import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException;
+import org.sufficientlysecure.keychain.provider.CachedPublicKeyRing;
 import org.sufficientlysecure.keychain.provider.KeychainContract;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.provider.ProviderHelper.NotFoundException;
@@ -112,12 +113,10 @@ public class PassphraseDialogActivity extends FragmentActivity {
 
         // handle empty passphrases by directly returning an empty crypto input parcel
         try {
-            CanonicalizedSecretKeyRing pubRing =
+            CachedPublicKeyRing pubRing =
-                    new ProviderHelper(this).getCanonicalizedSecretKeyRing(
+                    new ProviderHelper(this).getCachedPublicKeyRing(requiredInput.getMasterKeyId());
-                            requiredInput.getMasterKeyId());
             // use empty passphrase for empty passphrase
-            if (pubRing.getSecretKey(requiredInput.getSubKeyId()).getSecretKeyType() ==
+            if (pubRing.getSecretKeyType(requiredInput.getSubKeyId()) == SecretKeyType.PASSPHRASE_EMPTY) {
-                    SecretKeyType.PASSPHRASE_EMPTY) {
                 // also return passphrase back to activity
                 Intent returnIntent = new Intent();
                 cryptoInputParcel.mPassphrase = new Passphrase("");
@@ -161,7 +160,6 @@ public class PassphraseDialogActivity extends FragmentActivity {
         private TextView mPassphraseText;
         private EditText[] mBackupCodeEditText;
 
-        private CanonicalizedSecretKeyRing mSecretRing = null;
         private boolean mIsCancelled = false;
         private RequiredInputParcel mRequiredInput;
 
@@ -233,24 +231,20 @@ public class PassphraseDialogActivity extends FragmentActivity {
                     long subKeyId = mRequiredInput.getSubKeyId();
 
                     ProviderHelper helper = new ProviderHelper(activity);
-                    mSecretRing = helper.getCanonicalizedSecretKeyRing(
+                    CachedPublicKeyRing cachedPublicKeyRing = helper.getCachedPublicKeyRing(
                             KeychainContract.KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(subKeyId));
                     // yes the inner try/catch block is necessary, otherwise the final variable
                     // above can't be statically verified to have been set in all cases because
                     // the catch clause doesn't return.
-                    try {
+                    String mainUserId = cachedPublicKeyRing.getPrimaryUserIdWithFallback();
-                        String mainUserId = mSecretRing.getPrimaryUserIdWithFallback();
+                    KeyRing.UserId mainUserIdSplit = KeyRing.splitUserId(mainUserId);
-                        KeyRing.UserId mainUserIdSplit = KeyRing.splitUserId(mainUserId);
+                    if (mainUserIdSplit.name != null) {
-                        if (mainUserIdSplit.name != null) {
+                        userId = mainUserIdSplit.name;
-                            userId = mainUserIdSplit.name;
+                    } else {
-                        } else {
+                        userId = getString(R.string.user_id_no_name);
-                            userId = getString(R.string.user_id_no_name);
-                        }
-                    } catch (PgpKeyNotFoundException e) {
-                        userId = null;
                     }
 
-                    keyType = mSecretRing.getSecretKey(subKeyId).getSecretKeyType();
+                    keyType = cachedPublicKeyRing.getSecretKeyType(subKeyId);
                     switch (keyType) {
                         case PASSPHRASE:
                             message = getString(R.string.passphrase_for, userId);
@@ -271,7 +265,7 @@ public class PassphraseDialogActivity extends FragmentActivity {
                             throw new AssertionError("Unhandled SecretKeyType (should not happen)");
                     }
 
-                } catch (ProviderHelper.NotFoundException e) {
+                } catch (PgpKeyNotFoundException | ProviderHelper.NotFoundException e) {
                     alert.setTitle(R.string.title_key_not_found);
                     alert.setMessage(getString(R.string.key_not_found, mRequiredInput.getSubKeyId()));
                     alert.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
@@ -389,7 +383,7 @@ public class PassphraseDialogActivity extends FragmentActivity {
                     final int timeToLiveSeconds = mTimeToLiveSpinner.getSelectedTimeToLive();
 
                     // Early breakout if we are dealing with a symmetric key
-                    if (mSecretRing == null) {
+                    if (mRequiredInput.mType == RequiredInputType.PASSPHRASE_SYMMETRIC) {
                         if (!mRequiredInput.mSkipCaching) {
                             PassphraseCacheService.addCachedPassphrase(getActivity(),
                                     Constants.key.symmetric, Constants.key.symmetric, passphrase,
@@ -403,32 +397,48 @@ public class PassphraseDialogActivity extends FragmentActivity {
                     mLayout.setDisplayedChild(1);
                     positive.setEnabled(false);
 
-                    new AsyncTask<Void, Void, Boolean>() {
+                    new AsyncTask<Void, Void, CanonicalizedSecretKey>() {
+
                         @Override
-                        protected Boolean doInBackground(Void... params) {
+                        protected CanonicalizedSecretKey doInBackground(Void... params) {
                             try {
-                                // wait some 100ms here, give the user time to appreciate the progress bar
+                                long timeBeforeOperation = System.currentTimeMillis();
-                                try {
+
-                                    Thread.sleep(100);
+                                Long subKeyId = mRequiredInput.getSubKeyId();
-                                } catch (InterruptedException e) {
+                                CanonicalizedSecretKeyRing secretKeyRing =
-                                    // never mind
+                                        new ProviderHelper(getActivity()).getCanonicalizedSecretKeyRing(
+                                                KeychainContract.KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(subKeyId));
+                                CanonicalizedSecretKey secretKeyToUnlock =
+                                        secretKeyRing.getSecretKey(subKeyId);
+
+                                // this is the operation may take a very long time (100ms to several seconds!)
+                                boolean unlockSucceeded = secretKeyToUnlock.unlock(passphrase);
+
+                                // if it didn't take that long, give the user time to appreciate the progress bar
+                                long operationTime = System.currentTimeMillis() -timeBeforeOperation;
+                                if (operationTime < 100) {
+                                    try {
+                                        Thread.sleep(100 -operationTime);
+                                    } catch (InterruptedException e) {
+                                        // ignore
+                                    }
                                 }
-                                // make sure this unlocks
+
-                                return mSecretRing.getSecretKey(mRequiredInput.getSubKeyId()).unlock(passphrase);
+                                return unlockSucceeded ? secretKeyToUnlock : null;
-                            } catch (PgpGeneralException e) {
+                            } catch (NotFoundException | PgpGeneralException e) {
                                 Toast.makeText(getActivity(), R.string.error_could_not_extract_private_key,
                                         Toast.LENGTH_SHORT).show();
 
                                 getActivity().setResult(RESULT_CANCELED);
                                 dismiss();
                                 getActivity().finish();
-                                return false;
+                                return null;
                             }
                         }
 
                         /** Handle a good or bad passphrase. This happens in the UI thread!  */
                         @Override
-                        protected void onPostExecute(Boolean result) {
+                        protected void onPostExecute(CanonicalizedSecretKey result) {
                             super.onPostExecute(result);
 
                             // if we were cancelled in the meantime, the result isn't relevant anymore
@@ -437,7 +447,7 @@ public class PassphraseDialogActivity extends FragmentActivity {
                             }
 
                             // if the passphrase was wrong, reset and re-enable the dialogue
-                            if (!result) {
+                            if (result == null) {
                                 mPassphraseEditText.setText("");
                                 mPassphraseEditText.setError(getString(R.string.wrong_passphrase));
                                 mLayout.setDisplayedChild(0);
@@ -455,8 +465,8 @@ public class PassphraseDialogActivity extends FragmentActivity {
 
                                 try {
                                     PassphraseCacheService.addCachedPassphrase(getActivity(),
-                                            mSecretRing.getMasterKeyId(), mRequiredInput.getSubKeyId(), passphrase,
+                                            mRequiredInput.getMasterKeyId(), mRequiredInput.getSubKeyId(), passphrase,
-                                            mSecretRing.getPrimaryUserIdWithFallback(), timeToLiveSeconds);
+                                            result.getRing().getPrimaryUserIdWithFallback(), timeToLiveSeconds);
                                 } catch (PgpKeyNotFoundException e) {
                                     Log.e(Constants.TAG, "adding of a passphrase failed", e);
                                 }