Merge branch 'release/1.5.18'

build.gradle

@@ -42,7 +42,7 @@ allprojects {
 	ext {
 		androidApplicationId = 'org.cryptomator'
 		androidVersionCode = getVersionCode()
-		androidVersionName = '1.5.17'
+		androidVersionName = '1.5.18'
 	}
 	repositories {
 		mavenCentral()

buildsystem/dependencies.gradle

@@ -26,7 +26,7 @@ ext {
 	rxAndroidVersion = '2.1.1'
 	rxBindingVersion = '2.2.0'
 
-	daggerVersion = '2.34.1'
+	daggerVersion = '2.35'
 
 	gsonVersion = '2.8.6'
 
@@ -37,7 +37,7 @@ ext {
 
 	timberVersion = '4.7.1'
 
-	zxcvbnVersion = '1.4.1'
+	zxcvbnVersion = '1.5.0'
 
 	scaleImageViewVersion = '3.10.0'
 
@@ -51,6 +51,8 @@ ext {
 	// do not update to 1.4.0 until minsdk is 7.x (or desugaring works better) otherwise it will crash on 6.x
 	cryptolibVersion = '1.3.0'
 
+	awsAndroidSdkS3 = '2.23.0'
+
 	dropboxVersion = '4.0.0'
 
 	googleApiServicesVersion = 'v3-rev197-1.25.0'
@@ -101,6 +103,7 @@ ext {
 			androidxViewpager     : "androidx.viewpager:viewpager:${androidxViewpagerVersion}",
 			androidxSwiperefresh  : "androidx.swiperefreshlayout:swiperefreshlayout:${androidxSwiperefreshVersion}",
 			androidxPreference    : "androidx.preference:preference:${androidxPreferenceVersion}",
+			awsAndroidS3          : "com.amazonaws:aws-android-sdk-s3:${awsAndroidSdkS3}",
 			documentFile          : "androidx.documentfile:documentfile:${androidxDocumentfileVersion}",
 			recyclerView          : "androidx.recyclerview:recyclerview:${androidxRecyclerViewVersion}",
 			androidxTestCore      : "androidx.test:core:${androidxTestCoreVersion}",

data/build.gradle

@@ -74,7 +74,7 @@ android {
 }
 
 greendao {
-	schemaVersion 5
+	schemaVersion 6
 }
 
 configurations.all {
@@ -99,6 +99,7 @@ dependencies {
 	annotationProcessor dependencies.daggerCompiler
 	implementation dependencies.dagger
 	// cloud
+	implementation dependencies.awsAndroidS3
 	implementation dependencies.dropbox
 	implementation dependencies.msgraph
 

data/src/foss/java/org/cryptomator/data/cloud/CloudContentRepositoryFactories.java

@@ -5,6 +5,7 @@ import org.cryptomator.data.cloud.dropbox.DropboxCloudContentRepositoryFactory;
 import org.cryptomator.data.cloud.local.LocalStorageContentRepositoryFactory;
 import org.cryptomator.data.cloud.onedrive.OnedriveCloudContentRepositoryFactory;
 import org.cryptomator.data.cloud.pcloud.PCloudContentRepositoryFactory;
+import org.cryptomator.data.cloud.s3.S3CloudContentRepositoryFactory;
 import org.cryptomator.data.cloud.webdav.WebDavCloudContentRepositoryFactory;
 import org.cryptomator.data.repository.CloudContentRepositoryFactory;
 import org.jetbrains.annotations.NotNull;
@@ -25,6 +26,7 @@ public class CloudContentRepositoryFactories implements Iterable<CloudContentRep
 	public CloudContentRepositoryFactories(DropboxCloudContentRepositoryFactory dropboxFactory, //
 			OnedriveCloudContentRepositoryFactory oneDriveFactory, //
 			PCloudContentRepositoryFactory pCloudFactory, //
+			S3CloudContentRepositoryFactory s3Factory, //
 			CryptoCloudContentRepositoryFactory cryptoFactory, //
 			LocalStorageContentRepositoryFactory localStorageFactory, //
 			WebDavCloudContentRepositoryFactory webDavFactory) {
@@ -32,6 +34,7 @@ public class CloudContentRepositoryFactories implements Iterable<CloudContentRep
 		factories = asList(dropboxFactory, //
 				oneDriveFactory, //
 				pCloudFactory, //
+				s3Factory, //
 				cryptoFactory, //
 				localStorageFactory, //
 				webDavFactory);

data/src/main/java/org/cryptomator/data/cloud/pcloud/PCloudNodeFactory.java

@@ -16,8 +16,8 @@ class PCloudNodeFactory {
 		return new PCloudFile(parent, name, getNodePath(parent, name), size, Optional.empty());
 	}
 
-	public static PCloudFile file(PCloudFolder folder, String name, Optional<Long> size, String path) {
-		return new PCloudFile(folder, name, path, size, Optional.empty());
+	public static PCloudFile file(PCloudFolder parent, String name, Optional<Long> size, String path) {
+		return new PCloudFile(parent, name, path, size, Optional.empty());
 	}
 
 	public static PCloudFolder folder(PCloudFolder parent, RemoteFolder folder) {

data/src/main/java/org/cryptomator/data/cloud/s3/RootS3Folder.java

@@ -0,0 +1,29 @@
+package org.cryptomator.data.cloud.s3;
+
+import org.cryptomator.domain.Cloud;
+import org.cryptomator.domain.S3Cloud;
+
+class RootS3Folder extends S3Folder {
+
+	private final S3Cloud cloud;
+
+	public RootS3Folder(S3Cloud cloud) {
+		super(null, "", "");
+		this.cloud = cloud;
+	}
+
+	@Override
+	public S3Cloud getCloud() {
+		return cloud;
+	}
+
+	@Override
+	public String getKey() {
+		return "";
+	}
+
+	@Override
+	public S3Folder withCloud(Cloud cloud) {
+		return new RootS3Folder((S3Cloud) cloud);
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3ClientFactory.java

@@ -0,0 +1,87 @@
+package org.cryptomator.data.cloud.s3;
+
+import android.content.Context;
+
+import com.amazonaws.Request;
+import com.amazonaws.Response;
+import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.handlers.RequestHandler2;
+import com.amazonaws.regions.Region;
+import com.amazonaws.regions.Regions;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3Client;
+
+import org.cryptomator.domain.S3Cloud;
+import org.cryptomator.util.crypto.CredentialCryptor;
+
+import timber.log.Timber;
+
+class S3ClientFactory {
+
+	private AmazonS3 apiClient;
+
+	public AmazonS3 getClient(S3Cloud cloud, Context context) {
+		if (apiClient == null) {
+			apiClient = createApiClient(cloud, context);
+		}
+		return apiClient;
+	}
+
+	private AmazonS3 createApiClient(S3Cloud cloud, Context context) {
+		Region region = Region.getRegion(Regions.DEFAULT_REGION);
+		String endpoint = null;
+
+		if (cloud.s3Region() != null) {
+			region = Region.getRegion(cloud.s3Region());
+		} else if (cloud.s3Endpoint() != null) {
+			endpoint = cloud.s3Endpoint();
+		}
+
+		AmazonS3Client client = new AmazonS3Client(new BasicAWSCredentials(decrypt(cloud.accessKey(), context), decrypt(cloud.secretKey(), context)), region);
+
+		if (endpoint != null) {
+			client.setEndpoint(cloud.s3Endpoint());
+		}
+
+		client.addRequestHandler(new LoggingAwareRequestHandler());
+
+		return client;
+	}
+
+	private String decrypt(String password, Context context) {
+		return CredentialCryptor //
+				.getInstance(context) //
+				.decrypt(password);
+	}
+
+	private static class LoggingAwareRequestHandler extends RequestHandler2 {
+
+		@Override
+		public void beforeRequest(Request<?> request) {
+			Timber.tag("S3Client").d("Sending request (%s) %s", request.getAWSRequestMetrics().getTimingInfo().getStartTimeNano(), request.toString());
+		}
+
+		@Override
+		public void afterResponse(Request<?> request, Response<?> response) {
+			Timber.tag("S3Client").d( //
+					"Response received (%s) with status %s (%s)", //
+					request.getAWSRequestMetrics().getTimingInfo().getStartTimeNano(), //
+					response.getHttpResponse().getStatusText(), //
+					response.getHttpResponse().getStatusCode());
+		}
+
+		@Override
+		public void afterError(Request<?> request, Response<?> response, Exception e) {
+			if (response != null) {
+				Timber.tag("S3Client").e( //
+						e, //
+						"Error occurred (%s) with status %s (%s)", //
+						request.getAWSRequestMetrics().getTimingInfo().getStartTimeNano(), //
+						response.getHttpResponse().getStatusText(), //
+						response.getHttpResponse().getStatusCode());
+			} else {
+				Timber.tag("S3Client").e(e, "Error occurred (%s)", request.getAWSRequestMetrics().getTimingInfo().getStartTimeNano());
+			}
+		}
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3CloudApiErrorCodes.java

@@ -0,0 +1,22 @@
+package org.cryptomator.data.cloud.s3;
+
+public enum S3CloudApiErrorCodes {
+	ACCESS_DENIED("AccessDenied"),
+	ACCOUNT_PROBLEM("AccountProblem"),
+	INTERNAL_ERROR("InternalError"),
+	INVALID_ACCESS_KEY_ID("InvalidAccessKeyId"),
+	INVALID_BUCKET_NAME("InvalidBucketName"),
+	INVALID_OBJECT_STATE("InvalidObjectState"),
+	NO_SUCH_BUCKET("NoSuchBucket"),
+	NO_SUCH_KEY("NoSuchKey");
+
+	private final String value;
+
+	S3CloudApiErrorCodes(final String newValue) {
+		value = newValue;
+	}
+
+	public String getValue() {
+		return value;
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3CloudApiExceptions.java

@@ -0,0 +1,14 @@
+package org.cryptomator.data.cloud.s3;
+
+public class S3CloudApiExceptions {
+
+	public static boolean isAccessProblem(String errorCode) {
+		return errorCode.equals(S3CloudApiErrorCodes.ACCESS_DENIED.getValue())
+				|| errorCode.equals(S3CloudApiErrorCodes.ACCOUNT_PROBLEM.getValue())
+				|| errorCode.equals(S3CloudApiErrorCodes.INVALID_ACCESS_KEY_ID.getValue());
+	}
+
+	public static boolean isNoSuchBucketException(String errorCode) {
+		return errorCode.equals(S3CloudApiErrorCodes.NO_SUCH_BUCKET.getValue());
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3CloudContentRepository.java

@@ -0,0 +1,187 @@
+package org.cryptomator.data.cloud.s3;
+
+import android.content.Context;
+
+import com.amazonaws.services.s3.model.AmazonS3Exception;
+
+import org.cryptomator.data.cloud.InterceptingCloudContentRepository;
+import org.cryptomator.domain.S3Cloud;
+import org.cryptomator.domain.exception.BackendException;
+import org.cryptomator.domain.exception.FatalBackendException;
+import org.cryptomator.domain.exception.NetworkConnectionException;
+import org.cryptomator.domain.exception.NoSuchBucketException;
+import org.cryptomator.domain.exception.authentication.WrongCredentialsException;
+import org.cryptomator.domain.repository.CloudContentRepository;
+import org.cryptomator.domain.usecases.ProgressAware;
+import org.cryptomator.domain.usecases.cloud.DataSource;
+import org.cryptomator.domain.usecases.cloud.DownloadState;
+import org.cryptomator.domain.usecases.cloud.UploadState;
+import org.cryptomator.util.Optional;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.List;
+
+import static org.cryptomator.util.ExceptionUtil.contains;
+
+class S3CloudContentRepository extends InterceptingCloudContentRepository<S3Cloud, S3Node, S3Folder, S3File> {
+
+	private final S3Cloud cloud;
+
+	public S3CloudContentRepository(S3Cloud cloud, Context context) {
+		super(new Intercepted(cloud, context));
+		this.cloud = cloud;
+	}
+
+	@Override
+	protected void throwWrappedIfRequired(Exception e) throws BackendException {
+		throwNoSuchBucketExceptionIfRequired(e);
+		throwConnectionErrorIfRequired(e);
+		throwWrongCredentialsExceptionIfRequired(e);
+	}
+
+	private void throwNoSuchBucketExceptionIfRequired(Exception e) throws NoSuchBucketException {
+		if (e instanceof AmazonS3Exception) {
+			String errorCode = ((AmazonS3Exception)e).getErrorCode();
+			if(S3CloudApiExceptions.isNoSuchBucketException(errorCode)) {
+				throw new NoSuchBucketException(cloud.s3Bucket());
+			}
+		}
+	}
+
+	private void throwConnectionErrorIfRequired(Exception e) throws NetworkConnectionException {
+		if (contains(e, IOException.class)) {
+			throw new NetworkConnectionException(e);
+		}
+	}
+
+	private void throwWrongCredentialsExceptionIfRequired(Exception e) {
+		if (e instanceof AmazonS3Exception) {
+			String errorCode = ((AmazonS3Exception) e).getErrorCode();
+			if (S3CloudApiExceptions.isAccessProblem(errorCode)) {
+				throw new WrongCredentialsException(cloud);
+			}
+		}
+	}
+
+	private static class Intercepted implements CloudContentRepository<S3Cloud, S3Node, S3Folder, S3File> {
+
+		private final S3Impl cloud;
+
+		public Intercepted(S3Cloud cloud, Context context) {
+			this.cloud = new S3Impl(context, cloud);
+		}
+
+		public S3Folder root(S3Cloud cloud) {
+			return this.cloud.root();
+		}
+
+		@Override
+		public S3Folder resolve(S3Cloud cloud, String path) throws BackendException {
+				return this.cloud.resolve(path);
+		}
+
+		@Override
+		public S3File file(S3Folder parent, String name) throws BackendException {
+			try {
+				return cloud.file(parent, name);
+			} catch (IOException ex) {
+				throw new FatalBackendException(ex);
+			}
+		}
+
+		@Override
+		public S3File file(S3Folder parent, String name, Optional<Long> size) throws BackendException {
+			try {
+				return cloud.file(parent, name, size);
+			} catch (IOException ex) {
+				throw new FatalBackendException(ex);
+			}
+		}
+
+		@Override
+		public S3Folder folder(S3Folder parent, String name) throws BackendException {
+			return cloud.folder(parent, name);
+		}
+
+		@Override
+		public boolean exists(S3Node node) throws BackendException {
+				return cloud.exists(node);
+		}
+
+		@Override
+		public List<S3Node> list(S3Folder folder) throws BackendException {
+			try {
+				return cloud.list(folder);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public S3Folder create(S3Folder folder) throws BackendException {
+			try {
+				return cloud.create(folder);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public S3Folder move(S3Folder source, S3Folder target) throws BackendException {
+			try {
+				return (S3Folder) cloud.move(source, target);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public S3File move(S3File source, S3File target) throws BackendException {
+			try {
+				return (S3File) cloud.move(source, target);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public S3File write(S3File uploadFile, DataSource data, ProgressAware<UploadState> progressAware, boolean replace, long size) throws BackendException {
+			try {
+				return cloud.write(uploadFile, data, progressAware, replace, size);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public void read(S3File file, Optional<File> encryptedTmpFile, OutputStream data, ProgressAware<DownloadState> progressAware) throws BackendException {
+			try {
+				cloud.read(file, encryptedTmpFile, data, progressAware);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public void delete(S3Node node) throws BackendException {
+			try {
+				cloud.delete(node);
+			} catch (IOException e) {
+				throw new FatalBackendException(e);
+			}
+		}
+
+		@Override
+		public String checkAuthenticationAndRetrieveCurrentAccount(S3Cloud cloud) throws BackendException {
+			return this.cloud.checkAuthenticationAndRetrieveCurrentAccount();
+		}
+
+		@Override
+		public void logout(S3Cloud cloud) throws BackendException {
+			// empty
+		}
+	}
+
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3CloudContentRepositoryFactory.java

@@ -0,0 +1,35 @@
+package org.cryptomator.data.cloud.s3;
+
+import android.content.Context;
+
+import org.cryptomator.data.repository.CloudContentRepositoryFactory;
+import org.cryptomator.domain.Cloud;
+import org.cryptomator.domain.S3Cloud;
+import org.cryptomator.domain.repository.CloudContentRepository;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import static org.cryptomator.domain.CloudType.S3;
+
+@Singleton
+public class S3CloudContentRepositoryFactory implements CloudContentRepositoryFactory {
+
+	private final Context context;
+
+	@Inject
+	public S3CloudContentRepositoryFactory(Context context) {
+		this.context = context;
+	}
+
+	@Override
+	public boolean supports(Cloud cloud) {
+		return cloud.type() == S3;
+	}
+
+	@Override
+	public CloudContentRepository cloudContentRepositoryFor(Cloud cloud) {
+		return new S3CloudContentRepository((S3Cloud) cloud, context);
+	}
+
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3CloudNodeFactory.java

@@ -0,0 +1,69 @@
+package org.cryptomator.data.cloud.s3;
+
+import com.amazonaws.services.s3.model.ObjectMetadata;
+import com.amazonaws.services.s3.model.S3ObjectSummary;
+
+import org.cryptomator.util.Optional;
+
+import java.util.Date;
+
+class S3CloudNodeFactory {
+
+	private static final String DELIMITER = "/";
+
+	public static S3File file(S3Folder parent, S3ObjectSummary file) {
+		String name = getNameFromKey(file.getKey());
+		return new S3File(parent, name, getNodePath(parent, name), Optional.ofNullable(file.getSize()), Optional.ofNullable(file.getLastModified()));
+	}
+
+	public static S3File file(S3Folder parent, String name, ObjectMetadata file) {
+		return new S3File(parent, name, getNodePath(parent, name), Optional.ofNullable(file.getContentLength()), Optional.ofNullable(file.getLastModified()));
+	}
+
+
+	public static S3File file(S3Folder parent, String name, Optional<Long> size) {
+		return new S3File(parent, name, getNodePath(parent, name), size, Optional.empty());
+	}
+
+	public static S3File file(S3Folder parent, String name, Optional<Long> size, String path) {
+		return new S3File(parent, name, path, size, Optional.empty());
+	}
+
+	public static S3File file(S3Folder parent, String name, Optional<Long> size, Optional<Date> lastModified) {
+		return new S3File(parent, name, getNodePath(parent, name), size, lastModified);
+	}
+
+	public static S3Folder folder(S3Folder parent, S3ObjectSummary folder) {
+		String name = getNameFromKey(folder.getKey());
+		return new S3Folder(parent, name, getNodePath(parent, name));
+	}
+
+	public static S3Folder folder(S3Folder parent, String name) {
+		return new S3Folder(parent, name, getNodePath(parent, name));
+	}
+
+	public static S3Folder folder(S3Folder parent, String name, String path) {
+		return new S3Folder(parent, name, path);
+	}
+
+	private static String getNodePath(S3Folder parent, String name) {
+		return parent.getKey() + name;
+	}
+
+	public static String getNameFromKey(String key) {
+		String name = key;
+		if (key.endsWith(DELIMITER)) {
+			name = key.substring(0, key.length() -1);
+		}
+		return name.contains(DELIMITER) ? name.substring(name.lastIndexOf(DELIMITER) + 1) : name;
+	}
+
+	public static S3Node from(S3Folder parent, S3ObjectSummary objectSummary) {
+		if (objectSummary.getKey().endsWith(DELIMITER)) {
+			return folder(parent, objectSummary);
+		} else {
+			return file(parent, objectSummary);
+		}
+	}
+
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3File.java

@@ -0,0 +1,60 @@
+package org.cryptomator.data.cloud.s3;
+
+import org.cryptomator.domain.Cloud;
+import org.cryptomator.domain.CloudFile;
+import org.cryptomator.util.Optional;
+
+import java.util.Date;
+
+class S3File implements CloudFile, S3Node {
+
+	private final S3Folder parent;
+	private final String name;
+	private final String path;
+	private final Optional<Long> size;
+	private final Optional<Date> modified;
+
+	public S3File(S3Folder parent, String name, String path, Optional<Long> size, Optional<Date> modified) {
+		this.parent = parent;
+		this.name = name;
+		this.path = path;
+		this.size = size;
+		this.modified = modified;
+	}
+
+	@Override
+	public Cloud getCloud() {
+		return parent.getCloud();
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public String getPath() {
+		return path;
+	}
+
+	@Override
+	public String getKey() {
+		return path;
+	}
+
+	@Override
+	public S3Folder getParent() {
+		return parent;
+	}
+
+	@Override
+	public Optional<Long> getSize() {
+		return size;
+	}
+
+	@Override
+	public Optional<Date> getModified() {
+		return modified;
+	}
+
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3Folder.java

@@ -0,0 +1,49 @@
+package org.cryptomator.data.cloud.s3;
+
+import org.cryptomator.domain.Cloud;
+import org.cryptomator.domain.CloudFolder;
+
+class S3Folder implements CloudFolder, S3Node {
+
+	private static final String DELIMITER = "/";
+
+	private final S3Folder parent;
+	private final String name;
+	private final String path;
+
+	public S3Folder(S3Folder parent, String name, String path) {
+		this.parent = parent;
+		this.name = name;
+		this.path = path;
+	}
+
+	@Override
+	public Cloud getCloud() {
+		return parent.getCloud();
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public String getPath() {
+		return path;
+	}
+
+	@Override
+	public String getKey() {
+		return path + DELIMITER;
+	}
+
+	@Override
+	public S3Folder getParent() {
+		return parent;
+	}
+
+	@Override
+	public S3Folder withCloud(Cloud cloud) {
+		return new S3Folder(parent.withCloud(cloud), name, path);
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3Impl.java

@@ -0,0 +1,417 @@
+package org.cryptomator.data.cloud.s3;
+
+import android.content.Context;
+
+import com.amazonaws.event.ProgressListener;
+import com.amazonaws.mobileconnectors.s3.transferutility.TransferListener;
+import com.amazonaws.mobileconnectors.s3.transferutility.TransferState;
+import com.amazonaws.mobileconnectors.s3.transferutility.TransferUtility;
+import com.amazonaws.mobileconnectors.s3.transferutility.UploadOptions;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.model.AmazonS3Exception;
+import com.amazonaws.services.s3.model.CopyObjectResult;
+import com.amazonaws.services.s3.model.DeleteObjectsRequest;
+import com.amazonaws.services.s3.model.DeleteObjectsRequest.KeyVersion;
+import com.amazonaws.services.s3.model.GetObjectRequest;
+import com.amazonaws.services.s3.model.ListObjectsV2Request;
+import com.amazonaws.services.s3.model.ListObjectsV2Result;
+import com.amazonaws.services.s3.model.ObjectMetadata;
+import com.amazonaws.services.s3.model.Owner;
+import com.amazonaws.services.s3.model.PutObjectRequest;
+import com.amazonaws.services.s3.model.S3Object;
+import com.amazonaws.services.s3.model.S3ObjectSummary;
+import com.tomclaw.cache.DiskLruCache;
+
+import org.cryptomator.data.util.CopyStream;
+import org.cryptomator.domain.S3Cloud;
+import org.cryptomator.domain.exception.BackendException;
+import org.cryptomator.domain.exception.CloudNodeAlreadyExistsException;
+import org.cryptomator.domain.exception.FatalBackendException;
+import org.cryptomator.domain.exception.ForbiddenException;
+import org.cryptomator.domain.exception.NoSuchBucketException;
+import org.cryptomator.domain.exception.NoSuchCloudFileException;
+import org.cryptomator.domain.exception.UnauthorizedException;
+import org.cryptomator.domain.exception.authentication.WrongCredentialsException;
+import org.cryptomator.domain.usecases.ProgressAware;
+import org.cryptomator.domain.usecases.cloud.DataSource;
+import org.cryptomator.domain.usecases.cloud.DownloadState;
+import org.cryptomator.domain.usecases.cloud.Progress;
+import org.cryptomator.domain.usecases.cloud.UploadState;
+import org.cryptomator.util.Optional;
+import org.cryptomator.util.SharedPreferencesHandler;
+import org.cryptomator.util.concurrent.CompletableFuture;
+import org.cryptomator.util.file.LruFileCacheUtil;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicLong;
+
+import timber.log.Timber;
+
+import static org.cryptomator.domain.usecases.cloud.Progress.progress;
+import static org.cryptomator.util.file.LruFileCacheUtil.Cache.S3;
+import static org.cryptomator.util.file.LruFileCacheUtil.retrieveFromLruCache;
+import static org.cryptomator.util.file.LruFileCacheUtil.storeToLruCache;
+
+class S3Impl {
+
+	private static final long CHUNKED_UPLOAD_MAX_SIZE = 100L << 20;
+	private static final String DELIMITER = "/";
+
+	private final S3ClientFactory clientFactory = new S3ClientFactory();
+	private final S3Cloud cloud;
+	private final RootS3Folder root;
+	private final Context context;
+
+	private final SharedPreferencesHandler sharedPreferencesHandler;
+	private DiskLruCache diskLruCache;
+
+	S3Impl(Context context, S3Cloud cloud) {
+		if (cloud.accessKey() == null || cloud.secretKey() == null) {
+			throw new WrongCredentialsException(cloud);
+		}
+
+		this.context = context;
+		this.cloud = cloud;
+		this.root = new RootS3Folder(cloud);
+		this.sharedPreferencesHandler = new SharedPreferencesHandler(context);
+	}
+
+	private AmazonS3 client() {
+		return clientFactory.getClient(cloud, context);
+	}
+
+	public S3Folder root() {
+		return root;
+	}
+
+	public S3Folder resolve(String path) {
+		if (path.startsWith(DELIMITER)) {
+			path = path.substring(1);
+		}
+		String[] names = path.split(DELIMITER);
+		S3Folder folder = root;
+		for (String name : names) {
+			if (!name.isEmpty()) {
+				folder = folder(folder, name);
+			}
+		}
+		return folder;
+	}
+
+	public S3File file(S3Folder parent, String name) throws BackendException, IOException {
+		return file(parent, name, Optional.empty());
+	}
+
+	public S3File file(S3Folder parent, String name, Optional<Long> size) throws BackendException, IOException {
+		return S3CloudNodeFactory.file(parent, name, size, parent.getKey() + name);
+	}
+
+	public S3Folder folder(S3Folder parent, String name) {
+		return S3CloudNodeFactory.folder(parent, name, parent.getKey() + name);
+	}
+
+	public boolean exists(S3Node node) {
+		String key = node.getKey();
+
+		ListObjectsV2Result result = client().listObjectsV2(cloud.s3Bucket(), key);
+
+		return result.getObjectSummaries().size() > 0;
+	}
+
+	public List<S3Node> list(S3Folder folder) throws IOException, BackendException {
+		List<S3Node> result = new ArrayList<>();
+
+		ListObjectsV2Request request = new ListObjectsV2Request().withBucketName(cloud.s3Bucket()).withPrefix(folder.getKey()).withDelimiter(DELIMITER);
+
+		ListObjectsV2Result listObjects = client().listObjectsV2(request);
+		for (String prefix : listObjects.getCommonPrefixes()) {
+			// add folders
+			result.add(S3CloudNodeFactory.folder(folder, S3CloudNodeFactory.getNameFromKey(prefix)));
+		}
+
+		for (S3ObjectSummary objectSummary : listObjects.getObjectSummaries()) {
+			// add files but skip parent folder
+			if (!objectSummary.getKey().equals(listObjects.getPrefix())) {
+				result.add(S3CloudNodeFactory.file(folder, objectSummary));
+			}
+		}
+		return result;
+	}
+
+	public S3Folder create(S3Folder folder) throws IOException, BackendException {
+		if (!exists(folder.getParent())) {
+			folder = new S3Folder( //
+					create(folder.getParent()), //
+					folder.getName(), folder.getPath() //
+			);
+		}
+
+		ObjectMetadata metadata = new ObjectMetadata();
+		metadata.setContentLength(0);
+
+		InputStream emptyContent = new ByteArrayInputStream(new byte[0]);
+
+		try {
+			PutObjectRequest putObjectRequest = new PutObjectRequest(cloud.s3Bucket(), folder.getKey(), emptyContent, metadata);
+			client().putObject(putObjectRequest);
+		} catch(AmazonS3Exception ex) {
+			handleApiError(ex, folder.getName());
+		}
+
+		return S3CloudNodeFactory.folder(folder.getParent(), folder.getName());
+	}
+
+	public S3Node move(S3Node source, S3Node target) throws IOException, BackendException {
+		if (exists(target)) {
+			throw new CloudNodeAlreadyExistsException(target.getName());
+		}
+
+		if (source instanceof S3Folder) {
+			ListObjectsV2Result listObjects = client().listObjectsV2(cloud.s3Bucket(), source.getPath());
+
+			if (listObjects.getObjectSummaries().size() > 0) {
+
+				List<DeleteObjectsRequest.KeyVersion> objectsToDelete = new ArrayList<>();
+
+				for (S3ObjectSummary summary : listObjects.getObjectSummaries()) {
+					objectsToDelete.add(new DeleteObjectsRequest.KeyVersion(summary.getKey()));
+					String destinationKey = summary.getKey().replace(source.getPath(), target.getPath());
+
+					client().copyObject(cloud.s3Bucket(), summary.getKey(), cloud.s3Bucket(), destinationKey);
+				}
+				client().deleteObjects(new DeleteObjectsRequest(cloud.s3Bucket()).withKeys(objectsToDelete));
+			} else {
+				throw new NoSuchCloudFileException(source.getPath());
+			}
+			return S3CloudNodeFactory.folder(target.getParent(), target.getName());
+		} else {
+			CopyObjectResult result = client().copyObject(cloud.s3Bucket(), source.getPath(), cloud.s3Bucket(), target.getPath());
+			client().deleteObject(cloud.s3Bucket(), source.getPath());
+			return S3CloudNodeFactory.file(target.getParent(), target.getName(), ((S3File) source).getSize(), Optional.of(result.getLastModifiedDate()));
+		}
+	}
+
+	public S3File write(S3File file, DataSource data, final ProgressAware<UploadState> progressAware, boolean replace, long size) throws IOException, BackendException {
+		if (!replace && exists(file)) {
+			throw new CloudNodeAlreadyExistsException("CloudNode already exists and replace is false");
+		}
+
+		progressAware.onProgress(Progress.started(UploadState.upload(file)));
+
+		final CompletableFuture<Optional<ObjectMetadata>> result = new CompletableFuture<>();
+
+		try {
+			if (size <= CHUNKED_UPLOAD_MAX_SIZE) {
+				uploadFile(file, data, progressAware, result, size);
+			} else {
+				uploadChunkedFile(file, data, progressAware, result, size);
+			}
+		} catch(AmazonS3Exception ex) {
+			handleApiError(ex, file.getName());
+		}
+
+		try {
+			Optional<ObjectMetadata> objectMetadataOptional = result.get();
+			ObjectMetadata objectMetadata = objectMetadataOptional.orElseGet(() -> client().getObjectMetadata(cloud.s3Bucket(), file.getPath()));
+			progressAware.onProgress(Progress.completed(UploadState.upload(file)));
+			return S3CloudNodeFactory.file(file.getParent(), file.getName(), objectMetadata);
+		} catch (ExecutionException | InterruptedException e) {
+			throw new FatalBackendException(e);
+		}
+
+	}
+
+	private void uploadFile(final S3File file, DataSource data, final ProgressAware<UploadState> progressAware, CompletableFuture<Optional<ObjectMetadata>> result, final long size) //
+			throws IOException {
+		AtomicLong bytesTransferred = new AtomicLong(0);
+		ProgressListener listener = progressEvent -> {
+			bytesTransferred.set(bytesTransferred.get() + progressEvent.getBytesTransferred());
+			progressAware.onProgress( //
+					progress(UploadState.upload(file)) //
+							.between(0) //
+							.and(size) //
+							.withValue(bytesTransferred.get()));
+		};
+
+		ObjectMetadata metadata = new ObjectMetadata();
+		metadata.setContentLength(data.size(context).get());
+
+		PutObjectRequest request = new PutObjectRequest(cloud.s3Bucket(), file.getPath(), data.open(context), metadata);
+		request.setGeneralProgressListener(listener);
+
+		result.complete(Optional.of(client().putObject(request).getMetadata()));
+	}
+
+	private void uploadChunkedFile(final S3File file, DataSource data, final ProgressAware<UploadState> progressAware, CompletableFuture<Optional<ObjectMetadata>> result, final long size) //
+			throws IOException {
+
+		TransferUtility tu = TransferUtility //
+				.builder() //
+				.s3Client(client()) //
+				.context(context) //
+				.defaultBucket(cloud.s3Bucket()) //
+				.build();
+
+		TransferListener transferListener = new TransferListener() {
+			@Override
+			public void onStateChanged(int id, TransferState state) {
+				if (state.equals(TransferState.COMPLETED)) {
+					progressAware.onProgress(Progress.completed(UploadState.upload(file)));
+					result.complete(Optional.empty());
+				}
+			}
+
+			@Override
+			public void onProgressChanged(int id, long bytesCurrent, long bytesTotal) {
+				progressAware.onProgress( //
+						progress(UploadState.upload(file)) //
+								.between(0) //
+								.and(size) //
+								.withValue(bytesCurrent));
+			}
+
+			@Override
+			public void onError(int id, Exception ex) {
+				result.fail(ex);
+			}
+		};
+
+		UploadOptions uploadOptions = UploadOptions.builder().transferListener(transferListener).build();
+
+		tu.upload(file.getPath(), data.open(context), uploadOptions);
+	}
+
+	public void read(S3File file, Optional<File> encryptedTmpFile, OutputStream data, final ProgressAware<DownloadState> progressAware) throws IOException, BackendException {
+		progressAware.onProgress(Progress.started(DownloadState.download(file)));
+
+		Optional<String> cacheKey = Optional.empty();
+		Optional<File> cacheFile = Optional.empty();
+
+		ListObjectsV2Result listObjects;
+
+		if (sharedPreferencesHandler.useLruCache() && createLruCache(sharedPreferencesHandler.lruCacheSize())) {
+			listObjects = client().listObjectsV2(cloud.s3Bucket(), file.getKey());
+			if (listObjects.getObjectSummaries().size() != 1) {
+				throw new NoSuchCloudFileException(file.getKey());
+			}
+			S3ObjectSummary summary = listObjects.getObjectSummaries().get(0);
+			cacheKey = Optional.of(summary.getKey() + summary.getETag());
+
+			File cachedFile = diskLruCache.get(cacheKey.get());
+			cacheFile = cachedFile != null ? Optional.of(cachedFile) : Optional.empty();
+		}
+
+		if (sharedPreferencesHandler.useLruCache() && cacheFile.isPresent()) {
+			try {
+				retrieveFromLruCache(cacheFile.get(), data);
+			} catch (IOException e) {
+				Timber.tag("S3Impl").w(e, "Error while retrieving content from Cache, get from web request");
+				writeToData(file, data, encryptedTmpFile, cacheKey, progressAware);
+			}
+		} else {
+			writeToData(file, data, encryptedTmpFile, cacheKey, progressAware);
+		}
+
+		progressAware.onProgress(Progress.completed(DownloadState.download(file)));
+	}
+
+	private void writeToData(final S3File file, //
+			final OutputStream data, //
+			final Optional<File> encryptedTmpFile, //
+			final Optional<String> cacheKey, //
+			final ProgressAware<DownloadState> progressAware) throws IOException, BackendException {
+		AtomicLong bytesTransferred = new AtomicLong(0);
+		ProgressListener listener = progressEvent -> {
+			bytesTransferred.set(bytesTransferred.get() + progressEvent.getBytesTransferred());
+
+			progressAware.onProgress( //
+					progress(DownloadState.download(file)) //
+							.between(0) //
+							.and(file.getSize().orElse(Long.MAX_VALUE)) //
+							.withValue(bytesTransferred.get()));
+		};
+
+		GetObjectRequest request = new GetObjectRequest(cloud.s3Bucket(), file.getPath());
+		request.setGeneralProgressListener(listener);
+
+		try {
+			S3Object s3Object = client().getObject(request);
+
+			CopyStream.copyStreamToStream(s3Object.getObjectContent(), data);
+
+			if (sharedPreferencesHandler.useLruCache() && encryptedTmpFile.isPresent() && cacheKey.isPresent()) {
+				try {
+					storeToLruCache(diskLruCache, cacheKey.get(), encryptedTmpFile.get());
+				} catch (IOException e) {
+					Timber.tag("S3Impl").e(e, "Failed to write downloaded file in LRU cache");
+				}
+			}
+		} catch(AmazonS3Exception ex) {
+			handleApiError(ex, file.getName());
+		}
+
+	}
+
+	public void delete(S3Node node) throws IOException, BackendException {
+		if (node instanceof S3Folder) {
+			List<S3ObjectSummary> summaries = client().listObjectsV2(cloud.s3Bucket(), node.getPath()).getObjectSummaries();
+
+			List<KeyVersion> keys = new ArrayList<>();
+			for (S3ObjectSummary summary : summaries) {
+				keys.add(new KeyVersion(summary.getKey()));
+			}
+
+			DeleteObjectsRequest request = new DeleteObjectsRequest(cloud.s3Bucket());
+			request.withKeys(keys);
+
+			client().deleteObjects(request);
+		} else {
+			client().deleteObject(cloud.s3Bucket(), node.getPath());
+		}
+	}
+
+	public String checkAuthenticationAndRetrieveCurrentAccount() throws NoSuchBucketException {
+		if (!client().doesBucketExist(cloud.s3Bucket())) {
+			throw new NoSuchBucketException(cloud.s3Bucket());
+		}
+
+		Owner currentAccount = client() //
+				.getS3AccountOwner();
+
+		return currentAccount.getDisplayName();
+	}
+
+	private boolean createLruCache(int cacheSize) {
+		if (diskLruCache == null) {
+			try {
+				diskLruCache = DiskLruCache.create(new LruFileCacheUtil(context).resolve(S3), cacheSize);
+			} catch (IOException e) {
+				Timber.tag("S3Impl").e(e, "Failed to setup LRU cache");
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	private void handleApiError(AmazonS3Exception ex, String name) throws BackendException {
+		String errorCode = ex.getErrorCode();
+		if (S3CloudApiExceptions.isAccessProblem(errorCode)) {
+			throw new ForbiddenException();
+		}  else if (S3CloudApiErrorCodes.NO_SUCH_BUCKET.getValue().equals(errorCode)) {
+			throw new NoSuchBucketException(name);
+		} else if (S3CloudApiErrorCodes.NO_SUCH_KEY.getValue().equals(errorCode)) {
+			throw new NoSuchCloudFileException(name);
+		}  else {
+			throw new FatalBackendException(ex);
+		}
+	}
+}

data/src/main/java/org/cryptomator/data/cloud/s3/S3Node.java

@@ -0,0 +1,12 @@
+package org.cryptomator.data.cloud.s3;
+
+import org.cryptomator.domain.CloudNode;
+
+interface S3Node extends CloudNode {
+
+	@Override
+	S3Folder getParent();
+
+	String getKey();
+
+}

data/src/main/java/org/cryptomator/data/db/DatabaseUpgrades.java

@@ -23,14 +23,16 @@ class DatabaseUpgrades {
 			Upgrade1To2 upgrade1To2, //
 			Upgrade2To3 upgrade2To3, //
 			Upgrade3To4 upgrade3To4, //
-			Upgrade4To5 upgrade4To5) {
+			Upgrade4To5 upgrade4To5, //
+			Upgrade5To6 upgrade5To6) {
 
 		availableUpgrades = defineUpgrades( //
 				upgrade0To1, //
 				upgrade1To2, //
 				upgrade2To3, //
 				upgrade3To4, //
-				upgrade4To5);
+				upgrade4To5, //
+				upgrade5To6);
 	}
 
 	private static Comparator<DatabaseUpgrade> reverseOrder() {

data/src/main/java/org/cryptomator/data/db/Upgrade5To6.kt

@@ -0,0 +1,76 @@
+package org.cryptomator.data.db
+
+import org.greenrobot.greendao.database.Database
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+internal class Upgrade5To6 @Inject constructor() : DatabaseUpgrade(5, 6) {
+
+	override fun internalApplyTo(db: Database, origin: Int) {
+		db.beginTransaction()
+		try {
+			changeCloudEntityToSupportS3(db)
+			db.setTransactionSuccessful()
+		} finally {
+			db.endTransaction()
+		}
+	}
+
+	private fun changeCloudEntityToSupportS3(db: Database) {
+		Sql.alterTable("CLOUD_ENTITY").renameTo("CLOUD_ENTITY_OLD").executeOn(db)
+
+		Sql.createTable("CLOUD_ENTITY") //
+				.id() //
+				.requiredText("TYPE") //
+				.optionalText("ACCESS_TOKEN") //
+				.optionalText("URL") //
+				.optionalText("USERNAME") //
+				.optionalText("WEBDAV_CERTIFICATE") //
+				.optionalText("S3_BUCKET") //
+				.optionalText("S3_REGION") //
+				.optionalText("S3_SECRET_KEY") //
+				.executeOn(db);
+
+		Sql.insertInto("CLOUD_ENTITY") //
+				.select("_id", "TYPE", "ACCESS_TOKEN", "URL", "USERNAME", "WEBDAV_CERTIFICATE") //
+				.columns("_id", "TYPE", "ACCESS_TOKEN", "URL", "USERNAME", "WEBDAV_CERTIFICATE") //
+				.from("CLOUD_ENTITY_OLD") //
+				.executeOn(db)
+
+		recreateVaultEntity(db)
+
+		Sql.dropTable("CLOUD_ENTITY_OLD").executeOn(db)
+	}
+
+	private fun recreateVaultEntity(db: Database) {
+		Sql.alterTable("VAULT_ENTITY").renameTo("VAULT_ENTITY_OLD").executeOn(db)
+		Sql.createTable("VAULT_ENTITY") //
+				.id() //
+				.optionalInt("FOLDER_CLOUD_ID") //
+				.optionalText("FOLDER_PATH") //
+				.optionalText("FOLDER_NAME") //
+				.requiredText("CLOUD_TYPE") //
+				.optionalText("PASSWORD") //
+				.optionalInt("POSITION") //
+				.foreignKey("FOLDER_CLOUD_ID", "CLOUD_ENTITY", Sql.SqlCreateTableBuilder.ForeignKeyBehaviour.ON_DELETE_SET_NULL) //
+				.executeOn(db)
+
+		Sql.insertInto("VAULT_ENTITY") //
+				.select("_id", "FOLDER_CLOUD_ID", "FOLDER_PATH", "FOLDER_NAME", "PASSWORD", "POSITION", "CLOUD_ENTITY.TYPE") //
+				.columns("_id", "FOLDER_CLOUD_ID", "FOLDER_PATH", "FOLDER_NAME", "PASSWORD", "POSITION", "CLOUD_TYPE") //
+				.from("VAULT_ENTITY_OLD") //
+				.join("CLOUD_ENTITY", "VAULT_ENTITY_OLD.FOLDER_CLOUD_ID") //
+				.executeOn(db)
+
+		Sql.dropIndex("IDX_VAULT_ENTITY_FOLDER_PATH_FOLDER_CLOUD_ID").executeOn(db)
+
+		Sql.createUniqueIndex("IDX_VAULT_ENTITY_FOLDER_PATH_FOLDER_CLOUD_ID") //
+				.on("VAULT_ENTITY") //
+				.asc("FOLDER_PATH") //
+				.asc("FOLDER_CLOUD_ID") //
+				.executeOn(db)
+
+		Sql.dropTable("VAULT_ENTITY_OLD").executeOn(db)
+	}
+}

data/src/main/java/org/cryptomator/data/db/entities/CloudEntity.java

@@ -22,14 +22,23 @@ public class CloudEntity extends DatabaseEntity {
 
 	private String webdavCertificate;
 
-	@Generated(hash = 361171073)
-	public CloudEntity(Long id, @NotNull String type, String accessToken, String url, String username, String webdavCertificate) {
+	private String s3Bucket;
+
+	private String s3Region;
+
+	private String s3SecretKey;
+
+	@Generated(hash = 1685351705)
+	public CloudEntity(Long id, @NotNull String type, String accessToken, String url, String username, String webdavCertificate, String s3Bucket, String s3Region, String s3SecretKey) {
 		this.id = id;
 		this.type = type;
 		this.accessToken = accessToken;
 		this.url = url;
 		this.username = username;
 		this.webdavCertificate = webdavCertificate;
+		this.s3Bucket = s3Bucket;
+		this.s3Region = s3Region;
+		this.s3SecretKey = s3SecretKey;
 	}
 
 	@Generated(hash = 1354152224)
@@ -83,4 +92,28 @@ public class CloudEntity extends DatabaseEntity {
 	public void setWebdavCertificate(String webdavCertificate) {
 		this.webdavCertificate = webdavCertificate;
 	}
+
+	public String getS3Bucket() {
+		return this.s3Bucket;
+	}
+
+	public void setS3Bucket(String s3Bucket) {
+		this.s3Bucket = s3Bucket;
+	}
+
+	public String getS3Region() {
+		return this.s3Region;
+	}
+
+	public void setS3Region(String s3Region) {
+		this.s3Region = s3Region;
+	}
+
+	public String getS3SecretKey() {
+		return this.s3SecretKey;
+	}
+
+	public void setS3SecretKey(String s3SecretKey) {
+		this.s3SecretKey = s3SecretKey;
+	}
 }

data/src/main/java/org/cryptomator/data/db/entities/VaultEntity.java

@@ -182,9 +182,7 @@ public class VaultEntity extends DatabaseEntity {
 		this.position = position;
 	}
 
-	/**
-	 * called by internal mechanisms, do not call yourself.
-	 */
+	/** called by internal mechanisms, do not call yourself. */
 	@Generated(hash = 674742652)
 	public void __setDaoSession(DaoSession daoSession) {
 		this.daoSession = daoSession;

data/src/main/java/org/cryptomator/data/db/mappers/CloudEntityMapper.java

@@ -8,6 +8,7 @@ import org.cryptomator.domain.GoogleDriveCloud;
 import org.cryptomator.domain.LocalStorageCloud;
 import org.cryptomator.domain.OnedriveCloud;
 import org.cryptomator.domain.PCloud;
+import org.cryptomator.domain.S3Cloud;
 import org.cryptomator.domain.WebDavCloud;
 
 import javax.inject.Inject;
@@ -18,6 +19,7 @@ import static org.cryptomator.domain.GoogleDriveCloud.aGoogleDriveCloud;
 import static org.cryptomator.domain.LocalStorageCloud.aLocalStorage;
 import static org.cryptomator.domain.OnedriveCloud.aOnedriveCloud;
 import static org.cryptomator.domain.PCloud.aPCloud;
+import static org.cryptomator.domain.S3Cloud.aS3Cloud;
 import static org.cryptomator.domain.WebDavCloud.aWebDavCloudCloud;
 
 @Singleton
@@ -43,6 +45,10 @@ public class CloudEntityMapper extends EntityMapper<CloudEntity, Cloud> {
 						.withAccessToken(entity.getAccessToken()) //
 						.withUsername(entity.getUsername()) //
 						.build();
+			case LOCAL:
+				return aLocalStorage() //
+						.withId(entity.getId()) //
+						.withRootUri(entity.getAccessToken()).build();
 			case ONEDRIVE:
 				return aOnedriveCloud() //
 						.withId(entity.getId()) //
@@ -56,10 +62,16 @@ public class CloudEntityMapper extends EntityMapper<CloudEntity, Cloud> {
 						.withAccessToken(entity.getAccessToken()) //
 						.withUsername(entity.getUsername()) //
 						.build();
-			case LOCAL:
-				return aLocalStorage() //
+			case S3:
+				return aS3Cloud() //
 						.withId(entity.getId()) //
-						.withRootUri(entity.getAccessToken()).build();
+						.withS3Endpoint(entity.getUrl()) //
+						.withS3Region(entity.getS3Region()) //
+						.withAccessKey(entity.getAccessToken()) //
+						.withSecretKey(entity.getS3SecretKey()) //
+						.withS3Bucket(entity.getS3Bucket()) //
+						.withDisplayName(entity.getUsername()) //
+						.build();
 			case WEBDAV:
 				return aWebDavCloudCloud() //
 						.withId(entity.getId()) //
@@ -87,6 +99,9 @@ public class CloudEntityMapper extends EntityMapper<CloudEntity, Cloud> {
 				result.setAccessToken(((GoogleDriveCloud) domainObject).accessToken());
 				result.setUsername(((GoogleDriveCloud) domainObject).username());
 				break;
+			case LOCAL:
+				result.setAccessToken(((LocalStorageCloud) domainObject).rootUri());
+				break;
 			case ONEDRIVE:
 				result.setAccessToken(((OnedriveCloud) domainObject).accessToken());
 				result.setUsername(((OnedriveCloud) domainObject).username());
@@ -96,8 +111,13 @@ public class CloudEntityMapper extends EntityMapper<CloudEntity, Cloud> {
 				result.setUrl(((PCloud) domainObject).url());
 				result.setUsername(((PCloud) domainObject).username());
 				break;
-			case LOCAL:
-				result.setAccessToken(((LocalStorageCloud) domainObject).rootUri());
+			case S3:
+				result.setUrl(((S3Cloud) domainObject).s3Endpoint());
+				result.setS3Region(((S3Cloud) domainObject).s3Region());
+				result.setAccessToken(((S3Cloud) domainObject).accessKey());
+				result.setS3SecretKey(((S3Cloud) domainObject).secretKey());
+				result.setS3Bucket(((S3Cloud) domainObject).s3Bucket());
+				result.setUsername(((S3Cloud) domainObject).displayName());
 				break;
 			case WEBDAV:
 				result.setAccessToken(((WebDavCloud) domainObject).password());

data/src/notFoss/java/org/cryptomator/data/cloud/CloudContentRepositoryFactories.java

@@ -6,6 +6,7 @@ import org.cryptomator.data.cloud.googledrive.GoogleDriveCloudContentRepositoryF
 import org.cryptomator.data.cloud.local.LocalStorageContentRepositoryFactory;
 import org.cryptomator.data.cloud.onedrive.OnedriveCloudContentRepositoryFactory;
 import org.cryptomator.data.cloud.pcloud.PCloudContentRepositoryFactory;
+import org.cryptomator.data.cloud.s3.S3CloudContentRepositoryFactory;
 import org.cryptomator.data.cloud.webdav.WebDavCloudContentRepositoryFactory;
 import org.cryptomator.data.repository.CloudContentRepositoryFactory;
 import org.jetbrains.annotations.NotNull;
@@ -27,6 +28,7 @@ public class CloudContentRepositoryFactories implements Iterable<CloudContentRep
 			GoogleDriveCloudContentRepositoryFactory googleDriveFactory, //
 			OnedriveCloudContentRepositoryFactory oneDriveFactory, //
 			PCloudContentRepositoryFactory pCloudFactory, //
+			S3CloudContentRepositoryFactory s3Factory, //
 			CryptoCloudContentRepositoryFactory cryptoFactory, //
 			LocalStorageContentRepositoryFactory localStorageFactory, //
 			WebDavCloudContentRepositoryFactory webDavFactory) {
@@ -35,6 +37,7 @@ public class CloudContentRepositoryFactories implements Iterable<CloudContentRep
 				googleDriveFactory, //
 				oneDriveFactory, //
 				pCloudFactory, //
+				s3Factory, //
 				cryptoFactory, //
 				localStorageFactory, //
 				webDavFactory);

domain/src/main/java/org/cryptomator/domain/CloudType.java

@@ -2,6 +2,6 @@ package org.cryptomator.domain;
 
 public enum CloudType {
 
-	DROPBOX, GOOGLE_DRIVE, ONEDRIVE, PCLOUD, WEBDAV, LOCAL, CRYPTO
+	DROPBOX, GOOGLE_DRIVE, ONEDRIVE, PCLOUD, WEBDAV, LOCAL, S3, CRYPTO
 
 }

domain/src/main/java/org/cryptomator/domain/S3Cloud.java

@@ -0,0 +1,179 @@
+package org.cryptomator.domain;
+
+import org.jetbrains.annotations.NotNull;
+
+public class S3Cloud implements Cloud {
+
+	private final Long id;
+	private final String accessKey;
+	private final String secretKey;
+	private final String s3Bucket;
+	private final String s3Endpoint;
+	private final String s3Region;
+	private final String displayName;
+
+	private S3Cloud(Builder builder) {
+		this.id = builder.id;
+		this.accessKey = builder.accessKey;
+		this.secretKey = builder.secretKey;
+		this.s3Bucket = builder.s3Bucket;
+		this.s3Endpoint = builder.s3Endpoint;
+		this.s3Region = builder.s3Region;
+		this.displayName = builder.displayName;
+	}
+
+	public static Builder aS3Cloud() {
+		return new Builder();
+	}
+
+	public static Builder aCopyOf(S3Cloud s3Cloud) {
+		return new Builder() //
+				.withId(s3Cloud.id()) //
+				.withAccessKey(s3Cloud.accessKey()) //
+				.withSecretKey(s3Cloud.secretKey()) //
+				.withS3Bucket(s3Cloud.s3Bucket()) //
+				.withS3Endpoint(s3Cloud.s3Endpoint()) //
+				.withS3Region(s3Cloud.s3Region()) //
+				.withDisplayName(s3Cloud.displayName());
+	}
+
+	@Override
+	public Long id() {
+		return id;
+	}
+
+	public String accessKey() {
+		return accessKey;
+	}
+
+	public String secretKey() {
+		return secretKey;
+	}
+
+	public String s3Bucket() {
+		return s3Bucket;
+	}
+
+	public String s3Endpoint() {
+		return s3Endpoint;
+	}
+
+	public String s3Region() {
+		return s3Region;
+	}
+
+	public String displayName() {
+		return displayName;
+	}
+
+	@Override
+	public CloudType type() {
+		return CloudType.S3;
+	}
+
+	@Override
+	public boolean configurationMatches(Cloud cloud) {
+		return cloud instanceof S3Cloud && configurationMatches((S3Cloud) cloud);
+	}
+
+	private boolean configurationMatches(S3Cloud cloud) {
+		return s3Bucket.equals(cloud.s3Bucket) && s3Endpoint.equals(cloud.s3Endpoint) && s3Region.equals(cloud.s3Region);
+	}
+
+
+	@Override
+	public boolean predefined() {
+		return false;
+	}
+
+	@Override
+	public boolean persistent() {
+		return true;
+	}
+
+	@Override
+	public boolean requiresNetwork() {
+		return true;
+	}
+
+	@NotNull
+	@Override
+	public String toString() {
+		return "S3";
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == null || getClass() != obj.getClass()) {
+			return false;
+		}
+		if (obj == this) {
+			return true;
+		}
+		return internalEquals((S3Cloud) obj);
+	}
+
+	@Override
+	public int hashCode() {
+		return id == null ? 0 : id.hashCode();
+	}
+
+	private boolean internalEquals(S3Cloud obj) {
+		return id != null && id.equals(obj.id);
+	}
+
+	public static class Builder {
+
+		private Long id;
+		private String accessKey;
+		private String secretKey;
+		private String s3Bucket;
+		private String s3Endpoint;
+		private String s3Region;
+		private String displayName;
+
+		private Builder() {
+		}
+
+		public Builder withId(Long id) {
+			this.id = id;
+			return this;
+		}
+
+		public Builder withAccessKey(String accessKey) {
+			this.accessKey = accessKey;
+			return this;
+		}
+
+		public Builder withSecretKey(String secretKey) {
+			this.secretKey = secretKey;
+			return this;
+		}
+
+		public Builder withS3Bucket(String s3Bucket) {
+			this.s3Bucket = s3Bucket;
+			return this;
+		}
+
+		public Builder withS3Endpoint(String s3Endpoint) {
+			this.s3Endpoint = s3Endpoint;
+			return this;
+		}
+
+		public Builder withS3Region(String s3Region) {
+			this.s3Region = s3Region;
+			return this;
+		}
+
+		public Builder withDisplayName(String displayName) {
+			this.displayName = displayName;
+			return this;
+		}
+
+		public S3Cloud build() {
+			return new S3Cloud(this);
+		}
+
+	}
+
+}

domain/src/main/java/org/cryptomator/domain/exception/NoSuchBucketException.java

@@ -0,0 +1,11 @@
+package org.cryptomator.domain.exception;
+
+public class NoSuchBucketException extends BackendException {
+
+	public NoSuchBucketException() {
+	}
+
+	public NoSuchBucketException(String name) {
+		super(name);
+	}
+}

domain/src/main/java/org/cryptomator/domain/usecases/cloud/ConnectToS3.java

@@ -0,0 +1,23 @@
+package org.cryptomator.domain.usecases.cloud;
+
+import org.cryptomator.domain.S3Cloud;
+import org.cryptomator.domain.exception.BackendException;
+import org.cryptomator.domain.repository.CloudContentRepository;
+import org.cryptomator.generator.Parameter;
+import org.cryptomator.generator.UseCase;
+
+@UseCase
+class ConnectToS3 {
+
+	private final CloudContentRepository cloudContentRepository;
+	private final S3Cloud cloud;
+
+	public ConnectToS3(CloudContentRepository cloudContentRepository, @Parameter S3Cloud cloud) {
+		this.cloudContentRepository = cloudContentRepository;
+		this.cloud = cloud;
+	}
+
+	public void execute() throws BackendException {
+		cloudContentRepository.checkAuthenticationAndRetrieveCurrentAccount(cloud);
+	}
+}

fastlane/Fastfile

@@ -177,25 +177,31 @@ platform :android do |options|
       }
     )
 
-    FileUtils.cp(lane_context[SharedValues::GRADLE_APK_OUTPUT_PATH], "repo/Cryptomator.apk")
+	if options[:beta]
+	  puts "Skipping deployment to F-Droid cause there isn't currently a beta channel"
+	else
+	  puts "Updating F-Droid"
 
-    sh("cp -r metadata/android/ metadata/org.cryptomator/")
-    FileUtils.cp("metadata/org.cryptomator/en-US/changelogs/default.txt", "metadata/org.cryptomator/en-US/changelogs/#{version}.txt")
-    FileUtils.cp("metadata/org.cryptomator/de-DE/changelogs/default.txt", "metadata/org.cryptomator/de-DE/changelogs/#{version}.txt")
-    sh("fdroid update && fdroid rewritemeta")
-    sh("rm -r metadata/org.cryptomator/")
+	  FileUtils.cp(lane_context[SharedValues::GRADLE_APK_OUTPUT_PATH], "repo/Cryptomator.apk")
 
-    aws_s3(
-        bucket: ENV['S3_BUCKET'],
-        endpoint: ENV['S3_ENDPOINT'],
-        region: ENV['S3_REGION'],
-        access_key: ENV['S3_ACCESS_KEY'],
-        secret_access_key: ENV['S3_SECRET_ACCESS_KEY'],
-        path: "android/fdroid",
-        folder: "fastlane/repo",
-        skip_html_upload: true,
-        apk: ''
-      )
+	  sh("cp -r metadata/android/ metadata/org.cryptomator/")
+	  FileUtils.cp("metadata/org.cryptomator/en-US/changelogs/default.txt", "metadata/org.cryptomator/en-US/changelogs/#{version}.txt")
+	  FileUtils.cp("metadata/org.cryptomator/de-DE/changelogs/default.txt", "metadata/org.cryptomator/de-DE/changelogs/#{version}.txt")
+	  sh("fdroid update && fdroid rewritemeta")
+	  sh("rm -r metadata/org.cryptomator/")
+
+	  aws_s3(
+		  bucket: ENV['S3_BUCKET'],
+		  endpoint: ENV['S3_ENDPOINT'],
+		  region: ENV['S3_REGION'],
+		  access_key: ENV['S3_ACCESS_KEY'],
+		  secret_access_key: ENV['S3_SECRET_ACCESS_KEY'],
+		  path: "android/fdroid",
+		  folder: "fastlane/repo",
+		  skip_html_upload: true,
+		  apk: ''
+		)
+	end
 
     FileUtils.cp(lane_context[SharedValues::GRADLE_APK_OUTPUT_PATH], "release/Cryptomator-#{version}_fdroid_signed.apk")
   end

fastlane/metadata/android/de-DE/changelogs/default.txt

@@ -1 +1,3 @@
-- Problem bei der pCloud-Anmeldung in der F-Droid-Variante behoben
+- Unterstützung für S3-kompatiblen Speicher hinzugefügt
+- Passwortrichtlinie verbessert, so dass Tresore mit sehr schlechten Passwörtern nicht mehr erstellt werden können
+- Problem bei der Dateisuche behoben, falls Globbing aktiviert, die Live-Suche deaktiviert und das Muster Großbuchstaben enthält

fastlane/metadata/android/en-US/changelogs/default.txt

@@ -1 +1,3 @@
-- Fixed pCloud login using F-Droid
+- Added support for S3 compatible storage
+- Enhanced password policy so that vaults with very bad passwords can no longer be created
+- Fixed problem in file search when globbing is enabled, live search is disabled and pattern contains uppercase characters

fastlane/release-notes.html

@@ -1,3 +1,5 @@
 <ul>
-  <li>Fixed pCloud login using F-Droid</li>
+  <li>Added support for S3 compatible storage</li>
+  <li>Enhanced password policy so that vaults with very bad passwords can no longer be created</li>
+  <li>Fixed problem in file search when globbing is enabled, live search is disabled and pattern contains uppercase characters</li>
 </ul>

presentation/src/foss/java/org/cryptomator/presentation/presenter/AuthenticateCloudPresenter.kt

@@ -37,10 +37,12 @@ import org.cryptomator.presentation.R
 import org.cryptomator.presentation.exception.ExceptionHandlers
 import org.cryptomator.presentation.exception.PermissionNotGrantedException
 import org.cryptomator.presentation.intent.AuthenticateCloudIntent
+import org.cryptomator.presentation.intent.Intents
 import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.CloudTypeModel
 import org.cryptomator.presentation.model.ProgressModel
 import org.cryptomator.presentation.model.ProgressStateModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import org.cryptomator.presentation.model.mappers.CloudModelMapper
 import org.cryptomator.presentation.ui.activity.view.AuthenticateCloudView
@@ -72,6 +74,7 @@ class AuthenticateCloudPresenter @Inject constructor( //
 			OnedriveAuthStrategy(),  //
 			PCloudAuthStrategy(), //
 			WebDAVAuthStrategy(),  //
+			S3AuthStrategy(), //
 			LocalStorageAuthStrategy() //
 	)
 
@@ -404,6 +407,38 @@ class AuthenticateCloudPresenter @Inject constructor( //
 		finish()
 	}
 
+	private inner class S3AuthStrategy : AuthStrategy {
+
+		private var authenticationStarted = false
+
+		override fun supports(cloud: CloudModel): Boolean {
+			return cloud.cloudType() == CloudTypeModel.S3
+		}
+
+		override fun resumed(intent: AuthenticateCloudIntent) {
+			when {
+				ExceptionUtil.contains(intent.error(), WrongCredentialsException::class.java) -> {
+					if (!authenticationStarted) {
+						startAuthentication(intent.cloud())
+						Toast.makeText(
+								context(),
+								String.format(getString(R.string.error_authentication_failed), intent.cloud().username()),
+								Toast.LENGTH_LONG).show()
+					}
+				}
+				else -> {
+					Timber.tag("AuthicateCloudPrester").e(intent.error())
+					failAuthentication(intent.cloud().name())
+				}
+			}
+		}
+
+		private fun startAuthentication(cloud: CloudModel) {
+			authenticationStarted = true
+			startIntent(Intents.s3AddOrChangeIntent().withS3Cloud(cloud as S3CloudModel))
+		}
+	}
+
 	private inner class LocalStorageAuthStrategy : AuthStrategy {
 
 		private var authenticationStarted = false

presentation/src/main/AndroidManifest.xml

@@ -108,6 +108,7 @@
 		<activity android:name=".ui.activity.LicensesActivity" />
 		<activity android:name=".ui.activity.SettingsActivity" />
 		<activity android:name=".ui.activity.WebDavAddOrChangeActivity" />
+		<activity android:name=".ui.activity.S3AddOrChangeActivity" />
 
 		<activity
 			android:name=".ui.activity.AuthenticateCloudActivity"

presentation/src/main/java/org/cryptomator/presentation/di/component/ActivityComponent.java

@@ -16,6 +16,7 @@ import org.cryptomator.presentation.ui.activity.EmptyDirIdFileInfoActivity;
 import org.cryptomator.presentation.ui.activity.ImagePreviewActivity;
 import org.cryptomator.presentation.ui.activity.LicenseCheckActivity;
 import org.cryptomator.presentation.ui.activity.LicensesActivity;
+import org.cryptomator.presentation.ui.activity.S3AddOrChangeActivity;
 import org.cryptomator.presentation.ui.activity.SetPasswordActivity;
 import org.cryptomator.presentation.ui.activity.SettingsActivity;
 import org.cryptomator.presentation.ui.activity.SharedFilesActivity;
@@ -31,6 +32,7 @@ import org.cryptomator.presentation.ui.fragment.CloudConnectionListFragment;
 import org.cryptomator.presentation.ui.fragment.CloudSettingsFragment;
 import org.cryptomator.presentation.ui.fragment.EmptyDirIdFileInfoFragment;
 import org.cryptomator.presentation.ui.fragment.ImagePreviewFragment;
+import org.cryptomator.presentation.ui.fragment.S3AddOrChangeFragment;
 import org.cryptomator.presentation.ui.fragment.SetPasswordFragment;
 import org.cryptomator.presentation.ui.fragment.SharedFilesFragment;
 import org.cryptomator.presentation.ui.fragment.TextEditorFragment;
@@ -114,4 +116,8 @@ public interface ActivityComponent {
 	void inject(AutoUploadChooseVaultFragment autoUploadChooseVaultFragment);
 
 	void inject(LicenseCheckActivity licenseCheckActivity);
+
+	void inject(S3AddOrChangeActivity s3AddOrChangeActivity);
+
+	void inject(S3AddOrChangeFragment s3AddOrChangeFragment);
 }

presentation/src/main/java/org/cryptomator/presentation/exception/ExceptionHandlers.kt

@@ -8,6 +8,7 @@ import org.cryptomator.domain.di.PerView
 import org.cryptomator.domain.exception.CloudAlreadyExistsException
 import org.cryptomator.domain.exception.CloudNodeAlreadyExistsException
 import org.cryptomator.domain.exception.NetworkConnectionException
+import org.cryptomator.domain.exception.NoSuchBucketException
 import org.cryptomator.domain.exception.NoSuchCloudFileException
 import org.cryptomator.domain.exception.UnableToDecryptWebdavPasswordException
 import org.cryptomator.domain.exception.VaultAlreadyExistException
@@ -45,6 +46,7 @@ class ExceptionHandlers @Inject constructor(private val context: Context, defaul
 		staticHandler(NoLicenseAvailableException::class.java, R.string.dialog_enter_license_no_content)
 		staticHandler(GeneralUpdateErrorException::class.java, R.string.error_general_update)
 		staticHandler(SSLHandshakePreAndroid5UpdateCheckException::class.java, R.string.error_general_update)
+		staticHandler(NoSuchBucketException::class.java, R.string.error_no_such_bucket)
 		exceptionHandlers.add(MissingCryptorExceptionHandler())
 		exceptionHandlers.add(CancellationExceptionHandler())
 		exceptionHandlers.add(NoSuchVaultExceptionHandler())

presentation/src/main/java/org/cryptomator/presentation/intent/S3AddOrChangeIntent.java

@@ -0,0 +1,13 @@
+package org.cryptomator.presentation.intent;
+
+import org.cryptomator.generator.Intent;
+import org.cryptomator.generator.Optional;
+import org.cryptomator.presentation.model.S3CloudModel;
+import org.cryptomator.presentation.ui.activity.S3AddOrChangeActivity;
+
+@Intent(S3AddOrChangeActivity.class)
+public interface S3AddOrChangeIntent {
+
+	@Optional
+	S3CloudModel s3Cloud();
+}

presentation/src/main/java/org/cryptomator/presentation/model/CloudTypeModel.kt

@@ -28,6 +28,11 @@ enum class CloudTypeModel(builder: Builder) {
 			.withVaultImageResource(R.drawable.webdav_vault) //
 			.withVaultSelectedImageResource(R.drawable.webdav_vault_selected) //
 			.withMultiInstances()),  //
+	S3(Builder("S3", R.string.cloud_names_s3) //
+			.withCloudImageResource(R.drawable.s3) //
+			.withVaultImageResource(R.drawable.s3_vault) //
+			.withVaultSelectedImageResource(R.drawable.s3_vault_selected) //
+			.withMultiInstances()),  //
 	LOCAL(Builder("LOCAL", R.string.cloud_names_local_storage) //
 			.withCloudImageResource(R.drawable.local_fs) //
 			.withVaultImageResource(R.drawable.local_fs_vault) //

presentation/src/main/java/org/cryptomator/presentation/model/S3CloudModel.kt

@@ -0,0 +1,48 @@
+package org.cryptomator.presentation.model
+
+import org.cryptomator.domain.Cloud
+import org.cryptomator.domain.S3Cloud
+import org.cryptomator.presentation.R
+
+class S3CloudModel(cloud: Cloud) : CloudModel(cloud) {
+
+	override fun name(): Int {
+		return R.string.cloud_names_s3
+	}
+
+	override fun username(): String {
+		return cloud().displayName()
+	}
+
+	override fun cloudType(): CloudTypeModel {
+		return CloudTypeModel.S3
+	}
+
+	fun id(): Long {
+		return cloud().id()
+	}
+
+	fun accessKey(): String {
+		return cloud().accessKey()
+	}
+
+	fun secretKey(): String {
+		return cloud().secretKey()
+	}
+
+	fun s3Bucket(): String {
+		return cloud().s3Bucket()
+	}
+
+	fun s3Endpoint(): String {
+		return cloud().s3Endpoint()
+	}
+
+	fun s3Region(): String {
+		return cloud().s3Region()
+	}
+
+	private fun cloud(): S3Cloud {
+		return toCloud() as S3Cloud
+	}
+}

presentation/src/main/java/org/cryptomator/presentation/model/mappers/CloudModelMapper.kt

@@ -10,6 +10,7 @@ import org.cryptomator.presentation.model.GoogleDriveCloudModel
 import org.cryptomator.presentation.model.LocalStorageModel
 import org.cryptomator.presentation.model.OnedriveCloudModel
 import org.cryptomator.presentation.model.PCloudModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import javax.inject.Inject
 
@@ -24,10 +25,11 @@ class CloudModelMapper @Inject constructor() : ModelMapper<CloudModel, Cloud>()
 		return when (CloudTypeModel.valueOf(domainObject.type())) {
 			CloudTypeModel.DROPBOX -> DropboxCloudModel(domainObject)
 			CloudTypeModel.GOOGLE_DRIVE -> GoogleDriveCloudModel(domainObject)
+			CloudTypeModel.LOCAL -> LocalStorageModel(domainObject)
 			CloudTypeModel.ONEDRIVE -> OnedriveCloudModel(domainObject)
 			CloudTypeModel.PCLOUD -> PCloudModel(domainObject)
+			CloudTypeModel.S3 -> S3CloudModel(domainObject)
 			CloudTypeModel.CRYPTO -> CryptoCloudModel(domainObject)
-			CloudTypeModel.LOCAL -> LocalStorageModel(domainObject)
 			CloudTypeModel.WEBDAV -> WebDavCloudModel(domainObject)
 		}
 	}

presentation/src/main/java/org/cryptomator/presentation/presenter/CloudConnectionListPresenter.kt

@@ -29,6 +29,7 @@ import org.cryptomator.presentation.intent.Intents
 import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.CloudTypeModel
 import org.cryptomator.presentation.model.LocalStorageModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import org.cryptomator.presentation.model.mappers.CloudModelMapper
 import org.cryptomator.presentation.ui.activity.view.CloudConnectionListView
@@ -129,7 +130,7 @@ class CloudConnectionListPresenter @Inject constructor( //
 
 	fun onAddConnectionClicked() {
 		when (selectedCloudType.get()) {
-			CloudTypeModel.WEBDAV -> requestActivityResult(ActivityResultCallbacks.addChangeWebDavCloud(),  //
+			CloudTypeModel.WEBDAV -> requestActivityResult(ActivityResultCallbacks.addChangeMultiCloud(),  //
 					Intents.webDavAddOrChangeIntent())
 			CloudTypeModel.PCLOUD -> {
 				val authIntent: Intent = AuthorizationActivity.createIntent(
@@ -143,6 +144,8 @@ class CloudConnectionListPresenter @Inject constructor( //
 				requestActivityResult(ActivityResultCallbacks.pCloudAuthenticationFinished(),  //
 						authIntent)
 			}
+			CloudTypeModel.S3 -> requestActivityResult(ActivityResultCallbacks.addChangeMultiCloud(),  //
+					Intents.s3AddOrChangeIntent())
 			CloudTypeModel.LOCAL -> openDocumentTree()
 		}
 	}
@@ -165,12 +168,20 @@ class CloudConnectionListPresenter @Inject constructor( //
 	}
 
 	fun onChangeCloudClicked(cloudModel: CloudModel) {
-		if (cloudModel.cloudType() == CloudTypeModel.WEBDAV) {
-			requestActivityResult(ActivityResultCallbacks.addChangeWebDavCloud(),  //
-					Intents.webDavAddOrChangeIntent() //
-							.withWebDavCloud(cloudModel as WebDavCloudModel))
-		} else {
-			throw IllegalStateException("Change cloud with type " + cloudModel.cloudType() + " is not supported")
+		when {
+			cloudModel.cloudType() == CloudTypeModel.WEBDAV -> {
+				requestActivityResult(ActivityResultCallbacks.addChangeMultiCloud(),  //
+						Intents.webDavAddOrChangeIntent() //
+								.withWebDavCloud(cloudModel as WebDavCloudModel))
+			}
+			cloudModel.cloudType() == CloudTypeModel.S3 -> {
+				requestActivityResult(ActivityResultCallbacks.addChangeMultiCloud(),  //
+						Intents.s3AddOrChangeIntent() //
+								.withS3Cloud(cloudModel as S3CloudModel))
+			}
+			else -> {
+				throw IllegalStateException("Change cloud with type " + cloudModel.cloudType() + " is not supported")
+			}
 		}
 	}
 
@@ -179,7 +190,7 @@ class CloudConnectionListPresenter @Inject constructor( //
 	}
 
 	@Callback
-	fun addChangeWebDavCloud(result: ActivityResult?) {
+	fun addChangeMultiCloud(result: ActivityResult?) {
 		loadCloudList()
 	}
 

presentation/src/main/java/org/cryptomator/presentation/presenter/CloudSettingsPresenter.kt

@@ -3,6 +3,7 @@ package org.cryptomator.presentation.presenter
 import org.cryptomator.domain.Cloud
 import org.cryptomator.domain.LocalStorageCloud
 import org.cryptomator.domain.PCloud
+import org.cryptomator.domain.S3Cloud
 import org.cryptomator.domain.WebDavCloud
 import org.cryptomator.domain.di.PerView
 import org.cryptomator.domain.exception.FatalBackendException
@@ -18,6 +19,7 @@ import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.CloudTypeModel
 import org.cryptomator.presentation.model.LocalStorageModel
 import org.cryptomator.presentation.model.PCloudModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import org.cryptomator.presentation.model.mappers.CloudModelMapper
 import org.cryptomator.presentation.ui.activity.view.CloudSettingsView
@@ -37,6 +39,7 @@ class CloudSettingsPresenter @Inject constructor( //
 			CloudTypeModel.CRYPTO,  //
 			CloudTypeModel.LOCAL,  //
 			CloudTypeModel.PCLOUD, //
+			CloudTypeModel.S3, //
 			CloudTypeModel.WEBDAV)
 
 	fun loadClouds() {
@@ -44,7 +47,7 @@ class CloudSettingsPresenter @Inject constructor( //
 	}
 
 	fun onCloudClicked(cloudModel: CloudModel) {
-		if (isWebdavOrPCloudOrLocal(cloudModel)) {
+		if (cloudModel.cloudType().isMultiInstance) {
 			startConnectionListActivity(cloudModel.cloudType())
 		} else {
 			if (isLoggedIn(cloudModel)) {
@@ -61,10 +64,6 @@ class CloudSettingsPresenter @Inject constructor( //
 		}
 	}
 
-	private fun isWebdavOrPCloudOrLocal(cloudModel: CloudModel): Boolean {
-		return cloudModel is WebDavCloudModel || cloudModel is LocalStorageModel || cloudModel is PCloudModel
-	}
-
 	private fun loginCloud(cloudModel: CloudModel) {
 		getCloudsUseCase //
 				.withCloudType(CloudTypeModel.valueOf(cloudModel.cloudType())) //
@@ -93,8 +92,9 @@ class CloudSettingsPresenter @Inject constructor( //
 
 	private fun effectiveTitle(cloudTypeModel: CloudTypeModel): String {
 		when (cloudTypeModel) {
-			CloudTypeModel.WEBDAV -> return context().getString(R.string.screen_cloud_settings_webdav_connections)
 			CloudTypeModel.PCLOUD -> return context().getString(R.string.screen_cloud_settings_pcloud_connections)
+			CloudTypeModel.WEBDAV -> return context().getString(R.string.screen_cloud_settings_webdav_connections)
+			CloudTypeModel.S3 -> return context().getString(R.string.screen_cloud_settings_s3_connections)
 			CloudTypeModel.LOCAL -> return context().getString(R.string.screen_cloud_settings_local_storage_locations)
 		}
 		return context().getString(R.string.screen_cloud_settings_title)
@@ -126,19 +126,24 @@ class CloudSettingsPresenter @Inject constructor( //
 					.filter { cloud -> !(BuildConfig.FLAVOR == "fdroid" && cloud.cloudType() == CloudTypeModel.GOOGLE_DRIVE) } //
 					.toMutableList() //
 					.also {
-						it.add(aWebdavCloud())
 						it.add(aPCloud())
+						it.add(aWebdavCloud())
+						it.add(aS3Cloud())
 						it.add(aLocalCloud())
 					}
 			view?.render(cloudModel)
 		}
 
+		private fun aPCloud(): PCloudModel {
+			return PCloudModel(PCloud.aPCloud().build())
+		}
+
 		private fun aWebdavCloud(): WebDavCloudModel {
 			return WebDavCloudModel(WebDavCloud.aWebDavCloudCloud().build())
 		}
 
-		private fun aPCloud(): PCloudModel {
-			return PCloudModel(PCloud.aPCloud().build())
+		private fun aS3Cloud(): S3CloudModel {
+			return S3CloudModel(S3Cloud.aS3Cloud().build())
 		}
 
 		private fun aLocalCloud(): CloudModel {

presentation/src/main/java/org/cryptomator/presentation/presenter/S3AddOrChangePresenter.kt

@@ -0,0 +1,104 @@
+package org.cryptomator.presentation.presenter
+
+import android.widget.Toast
+import org.cryptomator.domain.Cloud
+import org.cryptomator.domain.S3Cloud
+import org.cryptomator.domain.di.PerView
+import org.cryptomator.domain.usecases.cloud.AddOrChangeCloudConnectionUseCase
+import org.cryptomator.domain.usecases.cloud.ConnectToS3UseCase
+import org.cryptomator.presentation.R
+import org.cryptomator.presentation.exception.ExceptionHandlers
+import org.cryptomator.presentation.model.ProgressModel
+import org.cryptomator.presentation.model.ProgressStateModel
+import org.cryptomator.presentation.ui.activity.view.S3AddOrChangeView
+import org.cryptomator.util.crypto.CredentialCryptor
+import javax.inject.Inject
+
+@PerView
+class S3AddOrChangePresenter @Inject internal constructor( //
+		private val addOrChangeCloudConnectionUseCase: AddOrChangeCloudConnectionUseCase,  //
+		private val connectToS3UseCase: ConnectToS3UseCase,  //
+		exceptionMappings: ExceptionHandlers) : Presenter<S3AddOrChangeView>(exceptionMappings) {
+
+	fun checkUserInput(accessKey: String, secretKey: String, bucket: String, endpoint: String?, region: String?, cloudId: Long?, displayName: String) {
+		var statusMessage: String? = null
+
+		if (accessKey.isEmpty()) {
+			statusMessage = getString(R.string.screen_s3_settings_msg_access_key_not_empty)
+		}
+		if (secretKey.isEmpty()) {
+			statusMessage = getString(R.string.screen_s3_settings_msg_secret_key_not_empty)
+		}
+		if (bucket.isEmpty()) {
+			statusMessage = getString(R.string.screen_s3_settings_msg_bucket_not_empty)
+		}
+		if (displayName.isEmpty()) {
+			statusMessage = getString(R.string.screen_s3_settings_msg_display_name_not_empty)
+		}
+		if (endpoint.isNullOrEmpty() && region.isNullOrEmpty()) {
+			statusMessage = getString(R.string.screen_s3_settings_msg_endpoint_and_region_not_empty)
+		}
+
+		if (statusMessage != null) {
+			Toast.makeText(context(), statusMessage, Toast.LENGTH_SHORT).show()
+		} else {
+			view?.onCheckUserInputSucceeded(encrypt(accessKey), encrypt(secretKey), bucket, endpoint, region, cloudId, displayName)
+		}
+	}
+
+	private fun encrypt(text: String): String {
+		return CredentialCryptor //
+				.getInstance(context()) //
+				.encrypt(text)
+	}
+
+	private fun mapToCloud(accessKey: String, secretKey: String, bucket: String, endpoint: String?, region: String?, cloudId: Long?, displayName: String): S3Cloud {
+		var builder = S3Cloud //
+				.aS3Cloud() //
+				.withAccessKey(accessKey) //
+				.withSecretKey(secretKey) //
+				.withS3Bucket(bucket) //
+				.withS3Endpoint(endpoint) //
+				.withS3Region(region) //
+				.withDisplayName(displayName)
+
+		cloudId?.let { builder = builder.withId(cloudId) }
+
+		return builder.build()
+	}
+
+	fun authenticate(accessKey: String, secretKey: String, bucket: String, endpoint: String?, region: String?, cloudId: Long?, displayName: String) {
+		authenticate(mapToCloud(accessKey, secretKey, bucket, endpoint, region, cloudId, displayName))
+	}
+
+	private fun authenticate(cloud: S3Cloud) {
+		view?.showProgress(ProgressModel(ProgressStateModel.AUTHENTICATION))
+		connectToS3UseCase //
+				.withCloud(cloud) //
+				.run(object : DefaultResultHandler<Void?>() {
+					override fun onSuccess(void: Void?) {
+						onCloudAuthenticated(cloud)
+					}
+
+					override fun onError(e: Throwable) {
+						view?.showProgress(ProgressModel.COMPLETED)
+						super.onError(e)
+					}
+				})
+	}
+
+	private fun onCloudAuthenticated(cloud: Cloud) {
+		save(cloud)
+		finishWithResult(CloudConnectionListPresenter.SELECTED_CLOUD, cloud)
+	}
+
+	private fun save(cloud: Cloud) {
+		addOrChangeCloudConnectionUseCase //
+				.withCloud(cloud) //
+				.run(DefaultResultHandler())
+	}
+
+	init {
+		unsubscribeOnDestroy(addOrChangeCloudConnectionUseCase, connectToS3UseCase)
+	}
+}

presentation/src/main/java/org/cryptomator/presentation/ui/activity/BrowseFilesActivity.kt

@@ -46,7 +46,6 @@ import org.cryptomator.presentation.ui.dialog.SymLinkDialog
 import org.cryptomator.presentation.ui.dialog.UploadCloudFileDialog
 import org.cryptomator.presentation.ui.fragment.BrowseFilesFragment
 import java.util.ArrayList
-import java.util.Locale
 import java.util.regex.Pattern
 import javax.inject.Inject
 import kotlinx.android.synthetic.main.toolbar_layout.toolbar
@@ -545,7 +544,7 @@ class BrowseFilesActivity : BaseActivity(), //
 	}
 
 	override fun onQueryTextSubmit(query: String?): Boolean {
-		updateFilter(query?.toLowerCase(Locale.getDefault()))
+		updateFilter(query)
 		return false
 	}
 

presentation/src/main/java/org/cryptomator/presentation/ui/activity/CloudConnectionListActivity.kt

@@ -51,7 +51,7 @@ class CloudConnectionListActivity : BaseActivity(),
 
 	private fun connectionListFragment(): CloudConnectionListFragment = getCurrentFragment(R.id.fragmentContainer) as CloudConnectionListFragment
 
-	override fun createFragment(): Fragment? = CloudConnectionListFragment()
+	override fun createFragment(): Fragment = CloudConnectionListFragment()
 
 	override fun showNodeSettings(cloudModel: CloudModel) {
 		val cloudNodeSettingDialog = //

presentation/src/main/java/org/cryptomator/presentation/ui/activity/S3AddOrChangeActivity.kt

@@ -0,0 +1,37 @@
+package org.cryptomator.presentation.ui.activity
+
+import androidx.fragment.app.Fragment
+import org.cryptomator.generator.Activity
+import org.cryptomator.generator.InjectIntent
+import org.cryptomator.presentation.R
+import org.cryptomator.presentation.intent.S3AddOrChangeIntent
+import org.cryptomator.presentation.presenter.S3AddOrChangePresenter
+import org.cryptomator.presentation.ui.activity.view.S3AddOrChangeView
+import org.cryptomator.presentation.ui.fragment.S3AddOrChangeFragment
+import javax.inject.Inject
+import kotlinx.android.synthetic.main.toolbar_layout.toolbar
+
+@Activity
+class S3AddOrChangeActivity : BaseActivity(), S3AddOrChangeView {
+
+	@Inject
+	lateinit var s3AddOrChangePresenter: S3AddOrChangePresenter
+
+	@InjectIntent
+	lateinit var s3AddOrChangeIntent: S3AddOrChangeIntent
+
+	override fun setupView() {
+		toolbar.setTitle(R.string.screen_s3_settings_title)
+		setSupportActionBar(toolbar)
+	}
+
+	override fun createFragment(): Fragment = S3AddOrChangeFragment.newInstance(s3AddOrChangeIntent.s3Cloud())
+
+	override fun onCheckUserInputSucceeded(accessKey: String, secretKey: String, bucket: String, endpoint: String?, region: String?, cloudId: Long?, displayName: String) {
+		s3AddOrChangeFragment().hideKeyboard()
+		s3AddOrChangePresenter.authenticate(accessKey, secretKey, bucket, endpoint, region, cloudId, displayName)
+	}
+
+	private fun s3AddOrChangeFragment(): S3AddOrChangeFragment = getCurrentFragment(R.id.fragmentContainer) as S3AddOrChangeFragment
+
+}

presentation/src/main/java/org/cryptomator/presentation/ui/activity/view/S3AddOrChangeView.kt

@@ -0,0 +1,7 @@
+package org.cryptomator.presentation.ui.activity.view
+
+interface S3AddOrChangeView : View {
+
+	fun onCheckUserInputSucceeded(accessKey: String, secretKey: String, bucket: String, endpoint: String?, region: String?, cloudId: Long?, displayName: String)
+
+}

presentation/src/main/java/org/cryptomator/presentation/ui/adapter/CloudConnectionListAdapter.kt

@@ -8,6 +8,7 @@ import org.cryptomator.presentation.R
 import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.LocalStorageModel
 import org.cryptomator.presentation.model.PCloudModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import org.cryptomator.presentation.model.comparator.CloudModelComparator
 import org.cryptomator.presentation.ui.adapter.CloudConnectionListAdapter.CloudConnectionHolder
@@ -53,12 +54,19 @@ internal constructor(context: Context) : RecyclerViewBaseAdapter<CloudModel, Clo
 
 			itemView.setOnClickListener { callback.onCloudConnectionClicked(cloudModel) }
 
-			if (cloudModel is WebDavCloudModel) {
-				bindWebDavCloudModel(cloudModel)
-			} else if (cloudModel is PCloudModel) {
-				bindPCloudModel(cloudModel)
-			} else if (cloudModel is LocalStorageModel) {
-				bindLocalStorageCloudModel(cloudModel)
+			when (cloudModel) {
+				is WebDavCloudModel -> {
+					bindWebDavCloudModel(cloudModel)
+				}
+				is PCloudModel -> {
+					bindPCloudModel(cloudModel)
+				}
+				is S3CloudModel -> {
+					bindS3loudModel(cloudModel)
+				}
+				is LocalStorageModel -> {
+					bindLocalStorageCloudModel(cloudModel)
+				}
 			}
 		}
 
@@ -70,7 +78,6 @@ internal constructor(context: Context) : RecyclerViewBaseAdapter<CloudModel, Clo
 			} catch (e: URISyntaxException) {
 				throw FatalBackendException("path in WebDAV cloud isn't correct (no uri)")
 			}
-
 		}
 
 		private fun bindPCloudModel(cloudModel: PCloudModel) {
@@ -78,6 +85,12 @@ internal constructor(context: Context) : RecyclerViewBaseAdapter<CloudModel, Clo
 			itemView.cloudSubText.visibility = View.GONE
 		}
 
+
+		private fun bindS3loudModel(cloudModel: S3CloudModel) {
+			itemView.cloudText.text = cloudModel.username()
+			itemView.cloudSubText.visibility = View.GONE
+		}
+
 		private fun bindLocalStorageCloudModel(cloudModel: LocalStorageModel) {
 			if (cloudModel.location().isEmpty()) {
 				itemView.cloudText.text = cloudModel.storage()

presentation/src/main/java/org/cryptomator/presentation/ui/adapter/CloudSettingsAdapter.kt

@@ -39,19 +39,19 @@ constructor(private val context: Context) : RecyclerViewBaseAdapter<CloudModel,
 
 			itemView.cloudImage.setImageResource(cloudModel.cloudType().cloudImageResource)
 
-			if (webdav(cloudModel.cloudType())) {
-				itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_webdav_connections)
-			} else if (pCloud(cloudModel.cloudType())) {
-				itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_pcloud_connections)
-			} else if (local(cloudModel.cloudType())) {
-				itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_local_storage_locations)
-			} else {
-				itemView.cloudName.text = getCloudNameText(isAlreadyLoggedIn(cloudModel), cloudModel)
-				if (isAlreadyLoggedIn(cloudModel)) {
-					itemView.cloudUsername.text = cloudModel.username()
-					itemView.cloudUsername.visibility = View.VISIBLE
-				} else {
-					itemView.cloudUsername.visibility = View.GONE
+			when (cloudModel.cloudType()) {
+				CloudTypeModel.PCLOUD -> itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_pcloud_connections)
+				CloudTypeModel.S3 -> itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_s3_connections)
+				CloudTypeModel.WEBDAV -> itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_webdav_connections)
+				CloudTypeModel.LOCAL -> itemView.cloudName.text = context.getString(R.string.screen_cloud_settings_local_storage_locations)
+				else -> {
+					itemView.cloudName.text = getCloudNameText(isAlreadyLoggedIn(cloudModel), cloudModel)
+					if (isAlreadyLoggedIn(cloudModel)) {
+						itemView.cloudUsername.text = cloudModel.username()
+						itemView.cloudUsername.visibility = View.VISIBLE
+					} else {
+						itemView.cloudUsername.visibility = View.GONE
+					}
 				}
 			}
 
@@ -73,16 +73,4 @@ constructor(private val context: Context) : RecyclerViewBaseAdapter<CloudModel,
 				context.getString(R.string.screen_cloud_settings_log_in_to)
 		}
 	}
-
-	private fun local(cloudType: CloudTypeModel): Boolean {
-		return CloudTypeModel.LOCAL == cloudType
-	}
-
-	private fun webdav(cloudType: CloudTypeModel): Boolean {
-		return CloudTypeModel.WEBDAV == cloudType
-	}
-
-	private fun pCloud(cloudType: CloudTypeModel): Boolean {
-		return CloudTypeModel.PCLOUD == cloudType
-	}
 }

presentation/src/main/java/org/cryptomator/presentation/ui/bottomsheet/CloudConnectionSettingsBottomSheet.kt

@@ -8,6 +8,7 @@ import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.CloudTypeModel
 import org.cryptomator.presentation.model.LocalStorageModel
 import org.cryptomator.presentation.model.PCloudModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import kotlinx.android.synthetic.main.dialog_bottom_sheet_cloud_settings.change_cloud
 import kotlinx.android.synthetic.main.dialog_bottom_sheet_cloud_settings.delete_cloud
@@ -30,6 +31,7 @@ class CloudConnectionSettingsBottomSheet : BaseBottomSheet<CloudConnectionSettin
 		when (cloudModel.cloudType()) {
 			CloudTypeModel.WEBDAV -> bindViewForWebDAV(cloudModel as WebDavCloudModel)
 			CloudTypeModel.PCLOUD -> bindViewForPCloud(cloudModel as PCloudModel)
+			CloudTypeModel.S3 -> bindViewForS3(cloudModel as S3CloudModel)
 			CloudTypeModel.LOCAL -> bindViewForLocal(cloudModel as LocalStorageModel)
 			else -> throw IllegalStateException("Cloud model is not binded in the view")
 		}
@@ -66,6 +68,11 @@ class CloudConnectionSettingsBottomSheet : BaseBottomSheet<CloudConnectionSettin
 		tv_cloud_name.text = cloudModel.username()
 	}
 
+	private fun bindViewForS3(cloudModel: S3CloudModel) {
+		change_cloud.visibility = View.VISIBLE
+		tv_cloud_name.text = cloudModel.username()
+	}
+
 	companion object {
 
 		private const val CLOUD_NODE_ARG = "cloudModel"

presentation/src/main/java/org/cryptomator/presentation/ui/dialog/ChangePasswordDialog.kt

@@ -51,6 +51,14 @@ class ChangePasswordDialog : BaseProgressErrorDialog<ChangePasswordDialog.Callba
 			changePasswordButton?.let { button ->
 				et_new_retype_password.nextFocusForwardId = button.id
 			}
+
+			registerOnEditorDoneActionAndPerformButtonClick(et_new_retype_password) { changePasswordButton }
+
+			PasswordStrengthUtil() //
+					.startUpdatingPasswordStrengthMeter(et_new_password,  //
+							progressBarPwStrengthIndicator,  //
+							textViewPwStrengthIndicator, //
+							changePasswordButton)
 		}
 	}
 
@@ -83,11 +91,6 @@ class ChangePasswordDialog : BaseProgressErrorDialog<ChangePasswordDialog.Callba
 
 	override fun setupView() {
 		et_old_password.requestFocus()
-		registerOnEditorDoneActionAndPerformButtonClick(et_new_retype_password) { changePasswordButton }
-		PasswordStrengthUtil() //
-				.startUpdatingPasswortStrengthMeter(et_new_password,  //
-						progressBarPwStrengthIndicator,  //
-						textViewPwStrengthIndicator)
 		dialog?.let { showKeyboard(it) }
 	}
 

presentation/src/main/java/org/cryptomator/presentation/ui/fragment/S3AddOrChangeFragment.kt

@@ -0,0 +1,118 @@
+package org.cryptomator.presentation.ui.fragment
+
+import android.os.Bundle
+import android.view.inputmethod.EditorInfo
+import com.google.android.material.switchmaterial.SwitchMaterial
+import org.cryptomator.generator.Fragment
+import org.cryptomator.presentation.R
+import org.cryptomator.presentation.model.S3CloudModel
+import org.cryptomator.presentation.presenter.S3AddOrChangePresenter
+import org.cryptomator.util.crypto.CredentialCryptor
+import javax.inject.Inject
+import kotlinx.android.synthetic.main.fragment_setup_s3.accessKeyEditText
+import kotlinx.android.synthetic.main.fragment_setup_s3.bucketEditText
+import kotlinx.android.synthetic.main.fragment_setup_s3.createCloudButton
+import kotlinx.android.synthetic.main.fragment_setup_s3.displayNameEditText
+import kotlinx.android.synthetic.main.fragment_setup_s3.regionOrEndpointEditText
+import kotlinx.android.synthetic.main.fragment_setup_s3.regionOrEndpointEditTextLayout
+import kotlinx.android.synthetic.main.fragment_setup_s3.secretKeyEditText
+import kotlinx.android.synthetic.main.fragment_setup_s3.toggleCustomS3
+import timber.log.Timber
+
+@Fragment(R.layout.fragment_setup_s3)
+class S3AddOrChangeFragment : BaseFragment() {
+
+	@Inject
+	lateinit var s3AddOrChangePresenter: S3AddOrChangePresenter
+
+	private var cloudId: Long? = null
+
+	private val s3CloudModel: S3CloudModel?
+		get() = arguments?.getSerializable(ARG_S3_CLOUD) as? S3CloudModel
+
+	override fun setupView() {
+		createCloudButton.setOnClickListener { createCloud() }
+		createCloudButton.setOnEditorActionListener { _, actionId, _ ->
+			if (actionId == EditorInfo.IME_ACTION_DONE) {
+				createCloud()
+			}
+			false
+		}
+
+		showEditableCloudContent(s3CloudModel)
+
+		toggleCustomS3.setOnClickListener { switch ->
+			regionOrEndpointEditText.text?.clear()
+			toggleUseAmazonS3((switch as SwitchMaterial).isChecked)
+		}
+	}
+
+	private fun toggleUseAmazonS3(checked: Boolean) = if (checked) {
+		regionOrEndpointEditTextLayout.setHint(R.string.screen_s3_settings_region_label)
+	} else {
+		regionOrEndpointEditTextLayout.setHint(R.string.screen_s3_settings_endpoint_label)
+	}
+
+	private fun showEditableCloudContent(s3CloudModel: S3CloudModel?) {
+		s3CloudModel?.let {
+			cloudId = s3CloudModel.id()
+			displayNameEditText.setText(s3CloudModel.username())
+			accessKeyEditText.setText(decrypt(s3CloudModel.accessKey()))
+			secretKeyEditText.setText(decrypt(s3CloudModel.secretKey()))
+			bucketEditText.setText(s3CloudModel.s3Bucket())
+
+			if (it.s3Endpoint().isNotEmpty()) {
+				toggleCustomS3.isChecked = false
+				regionOrEndpointEditText.setText(s3CloudModel.s3Endpoint())
+				regionOrEndpointEditTextLayout.setHint(R.string.screen_s3_settings_endpoint_label)
+			} else {
+				regionOrEndpointEditText.setText(s3CloudModel.s3Region())
+				regionOrEndpointEditTextLayout.setHint(R.string.screen_s3_settings_region_label)
+			}
+		} ?: regionOrEndpointEditTextLayout.setHint(R.string.screen_s3_settings_region_label)
+	}
+
+	private fun decrypt(text: String?): String {
+		return if (text != null) {
+			try {
+				CredentialCryptor //
+						.getInstance(activity?.applicationContext) //
+						.decrypt(text)
+			} catch (e: RuntimeException) {
+				Timber.tag("S3AddOrChangeFragment").e(e, "Unable to decrypt password, clearing it")
+				""
+			}
+		} else ""
+	}
+
+	private fun createCloud() {
+		val accessKey = accessKeyEditText.text.toString().trim()
+		val secretKey = secretKeyEditText.text.toString().trim()
+		val bucket = bucketEditText.text.toString().trim()
+		val displayName = displayNameEditText.text.toString().trim()
+
+		if (toggleCustomS3.isChecked) {
+			s3AddOrChangePresenter.checkUserInput(accessKey, secretKey, bucket, null, regionOrEndpointEditText.text.toString().trim(), cloudId, displayName)
+		} else {
+			s3AddOrChangePresenter.checkUserInput(accessKey, secretKey, bucket, regionOrEndpointEditText.text.toString().trim(), null, cloudId, displayName)
+		}
+	}
+
+	fun hideKeyboard() {
+		hideKeyboard(bucketEditText)
+	}
+
+	companion object {
+
+		private const val ARG_S3_CLOUD = "S3_CLOUD"
+
+		fun newInstance(cloudModel: S3CloudModel?): S3AddOrChangeFragment {
+			val result = S3AddOrChangeFragment()
+			val args = Bundle()
+			args.putSerializable(ARG_S3_CLOUD, cloudModel)
+			result.arguments = args
+			return result
+		}
+	}
+
+}

presentation/src/main/java/org/cryptomator/presentation/ui/fragment/SetPasswordFragment.kt

@@ -29,9 +29,10 @@ class SetPasswordFragment : BaseFragment() {
 			}
 			false
 		}
-		passwordStrengthUtil.startUpdatingPasswortStrengthMeter(passwordEditText, //
+		passwordStrengthUtil.startUpdatingPasswordStrengthMeter(passwordEditText, //
 				progressBarPwStrengthIndicator, //
-				textViewPwStrengthIndicator)
+				textViewPwStrengthIndicator, //
+				createVaultButton)
 
 		passwordEditText.requestFocus()
 	}

presentation/src/main/java/org/cryptomator/presentation/util/PasswordStrength.kt

@@ -14,13 +14,21 @@ enum class PasswordStrength(val score: Int, val description: Int, val color: Int
 
 	companion object {
 
+		private const val MIN_PASSWORD_LENGTH = 8
+
 		private val zxcvbn = Zxcvbn()
 
 		fun forPassword(password: String, sanitizedInputs: List<String>): PasswordStrength {
-			return if (password.isEmpty()) {
-				EMPTY
-			} else {
-				forScore(zxcvbn.measure(password, sanitizedInputs).score).orElse(EMPTY)
+			return when {
+				password.isEmpty() -> {
+					EMPTY
+				}
+				password.length < MIN_PASSWORD_LENGTH -> {
+					EXTREMELY_WEAK
+				}
+				else -> {
+					forScore(zxcvbn.measure(password, sanitizedInputs).score).orElse(EMPTY)
+				}
 			}
 		}
 

presentation/src/main/java/org/cryptomator/presentation/util/PasswordStrengthUtil.java

@@ -1,6 +1,7 @@
 package org.cryptomator.presentation.util;
 
 import android.graphics.PorterDuff;
+import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ProgressBar;
 import android.widget.TextView;
@@ -40,9 +41,10 @@ public class PasswordStrengthUtil {
 	public PasswordStrengthUtil() {
 	}
 
-	public void startUpdatingPasswortStrengthMeter(EditText passwordInput, //
+	public void startUpdatingPasswordStrengthMeter(EditText passwordInput, //
 			final ProgressBar strengthMeter, //
-			final TextView strengthLabel) {
+			final TextView strengthLabel, //
+			final Button button) {
 		RxTextView.textChanges(passwordInput) //
 				.observeOn(Schedulers.computation()) //
 				.map(password -> PasswordStrength.Companion.forPassword(password.toString(), SANITIZED_INPUTS)) //
@@ -51,6 +53,7 @@ public class PasswordStrengthUtil {
 					strengthMeter.getProgressDrawable().setColorFilter(ResourceHelper.Companion.getColor(strength.getColor()), PorterDuff.Mode.SRC_IN);
 					strengthLabel.setText(strength.getDescription());
 					strengthMeter.setProgress(strength.getScore() + 1);
+					button.setEnabled(strength.getScore() > PasswordStrength.EXTREMELY_WEAK.getScore());
 				});
 	}
 }

presentation/src/main/res/layout/fragment_setup_s3.xml

@@ -0,0 +1,114 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+	android:layout_width="match_parent"
+	android:layout_height="match_parent">
+
+	<LinearLayout
+		android:layout_width="match_parent"
+		android:layout_height="wrap_content"
+		android:orientation="vertical"
+		android:padding="@dimen/activity_vertical_margin">
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+			<com.google.android.material.textfield.TextInputEditText
+				android:id="@+id/displayNameEditText"
+				android:layout_width="match_parent"
+				android:layout_height="wrap_content"
+				android:hint="@string/screen_s3_settings_display_name_label"
+				android:imeOptions="flagNoPersonalizedLearning"
+				android:maxLines="1"
+				android:singleLine="true" />
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+			<com.google.android.material.textfield.TextInputEditText
+				android:id="@+id/accessKeyEditText"
+				android:layout_width="match_parent"
+				android:layout_height="wrap_content"
+				android:hint="@string/screen_s3_settings_access_key_label"
+				android:imeOptions="flagNoPersonalizedLearning"
+				android:inputType="textPassword"
+				android:maxLines="1"
+				android:singleLine="true" />
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+			<com.google.android.material.textfield.TextInputEditText
+				android:id="@+id/secretKeyEditText"
+				android:layout_width="match_parent"
+				android:layout_height="wrap_content"
+				android:hint="@string/screen_s3_settings_secret_key_label"
+				android:imeOptions="flagNoPersonalizedLearning"
+				android:inputType="textPassword"
+				android:maxLines="1"
+				android:singleLine="true" />
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+			<com.google.android.material.textfield.TextInputEditText
+				android:id="@+id/bucketEditText"
+				android:layout_width="match_parent"
+				android:layout_height="wrap_content"
+				android:hint="@string/screen_s3_settings_bucket_label"
+				android:imeOptions="flagNoPersonalizedLearning"
+				android:maxLines="1"
+				android:singleLine="true" />
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.textfield.TextInputLayout
+			android:id="@+id/regionOrEndpointEditTextLayout"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content">
+
+			<com.google.android.material.textfield.TextInputEditText
+				android:id="@+id/regionOrEndpointEditText"
+				android:layout_width="match_parent"
+				android:layout_height="wrap_content"
+				android:imeOptions="flagNoPersonalizedLearning"
+				android:maxLines="1"
+				android:singleLine="true" />
+
+		</com.google.android.material.textfield.TextInputLayout>
+
+		<com.google.android.material.switchmaterial.SwitchMaterial
+			android:id="@+id/toggleCustomS3"
+			android:layout_width="wrap_content"
+			android:layout_height="wrap_content"
+			android:layout_marginTop="16dp"
+			android:checked="true"
+			android:text="@string/screen_s3_settings_amazon_s3_text" />
+
+		<Button
+			android:id="@+id/createCloudButton"
+			style="?android:textAppearanceSmall"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			android:layout_marginTop="16dp"
+			android:text="@string/screen_webdav_settings_done_button_text"
+			android:textStyle="bold" />
+
+	</LinearLayout>
+</ScrollView>

presentation/src/main/res/values-de/strings.xml

@@ -27,6 +27,7 @@
 	<string name="error_play_services_not_available">Die Play Services sind nicht installiert</string>
 	<string name="error_biometric_auth_aborted">Biometrischer Login abgebrochen</string>
 	<string name="error_file_not_found_after_opening_using_3party">Lokale Datei ist nach dem Zurückwechseln zu Cryptomator nicht mehr vorhanden. Mögliche Änderungen können nicht in die Cloud übertragen werden.</string>
+	<string name="error_no_such_bucket">Bucket existiert nicht</string>
 	<!-- # clouds -->
 	<!-- ## cloud names -->
 	<string name="cloud_names_local_storage">Lokaler Speicher</string>
@@ -119,6 +120,12 @@
 	<string name="screen_webdav_settings_msg_url_is_invalid">URL ist ungültig.</string>
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">Benutzername muss ausgefüllt werden.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">Passwort muss ausgefüllt werden.</string>
+	<!-- ## screen: s3 settings -->
+	<string name="screen_s3_settings_display_name_label">Anzeigename</string>
+	<string name="screen_s3_settings_bucket_label">Vorhandener Bucket</string>
+	<string name="screen_s3_settings_msg_display_name_not_empty">Der Anzeigename darf nicht leer sein</string>
+	<string name="screen_s3_settings_msg_bucket_not_empty">Bucket darf nicht leer sein</string>
+	<string name="screen_s3_settings_msg_endpoint_and_region_not_empty">Endpoint und Region dürfen nicht leer sein</string>
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_msg_name_empty">Tresorname muss ausgefüllt werden.</string>
 	<string name="screen_enter_vault_name_vault_label">Tresorname</string>
@@ -129,7 +136,7 @@
 	<string name="screen_set_password_button_text">Fertig</string>
 	<string name="screen_set_password_hint">WICHTIG: Wenn Sie Ihr Passwort vergessen, gibt es keine Möglichkeit die Daten zu entschlüsseln.</string>
 	<string name="screen_set_password_retype_password_label">Passwort wiederholen</string>
-	<string name="screen_set_password_strength_indicator_0">Sehr Schwach</string>
+	<string name="screen_set_password_strength_indicator_0">Zu schwach, um einen Tresor zu erstellen</string>
 	<string name="screen_set_password_strength_indicator_1">Schwach</string>
 	<string name="screen_set_password_strength_indicator_2">Mittel</string>
 	<string name="screen_set_password_strength_indicator_3">Stark</string>
@@ -178,6 +185,7 @@
 	<!-- ## screen: cloud settings -->
 	<string name="screen_cloud_settings_webdav_connections">WebDAV-Verbindungen</string>
 	<string name="screen_cloud_settings_pcloud_connections">pCloud-Verbindungen</string>
+	<string name="screen_cloud_settings_s3_connections">S3-Verbindungen</string>
 	<string name="screen_cloud_settings_local_storage_locations">Lokale Speicherorte</string>
 	<string name="screen_cloud_settings_log_in_to">Einloggen in</string>
 	<string name="screen_cloud_settings_sign_out_from_cloud">Abmelden von</string>

presentation/src/main/res/values-es/strings.xml

@@ -84,6 +84,7 @@
 	<string name="screen_webdav_settings_msg_url_is_invalid">La URL no es válida.</string>
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">El nombre de usuario no puede estar vacio.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">La contraseña no puede estar vacía.</string>
+	<!-- ## screen: s3 settings -->
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_msg_name_empty">El nombre de la caja fuerte no puede estar vacío.</string>
 	<string name="screen_enter_vault_name_vault_label">Nombre de la caja fuerte</string>

presentation/src/main/res/values-fr/strings.xml

@@ -42,7 +42,7 @@
 	<string name="snack_bar_action_title_sort">Trier par</string>
 	<string name="snack_bar_action_title_sort_az">A - Z</string>
 	<string name="snack_bar_action_title_sort_za">Z - A</string>
-	<string name="snack_bar_action_title_sort_newest">Plus récent</string>
+	<string name="snack_bar_action_title_sort_newest">Récent d\'abord</string>
 	<string name="snack_bar_action_title_sort_oldest">Plus ancien</string>
 	<string name="snack_bar_action_title_sort_biggest">Taille décroissante</string>
 	<string name="snack_bar_action_title_sort_smallest">Taille croissante</string>
@@ -121,6 +121,7 @@
 	<string name="screen_webdav_settings_msg_url_is_invalid">URL invalide.</string>
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">Le nom d\'utilisateur ne peut pas être vide.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">Le mot de passe ne peut pas être vide.</string>
+	<!-- ## screen: s3 settings -->
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_msg_name_empty">Le nom du coffre-fort ne peut pas être vide.</string>
 	<string name="screen_enter_vault_name_vault_label">Nom du coffre-fort</string>
@@ -131,7 +132,6 @@
 	<string name="screen_set_password_button_text">Terminé</string>
 	<string name="screen_set_password_hint">IMPORTANT: Si vous oubliez votre mot de passe, il n\'y aura aucun moyen de récupérer vos données.</string>
 	<string name="screen_set_password_retype_password_label">Retaper le mot de passe</string>
-	<string name="screen_set_password_strength_indicator_0">Très faible</string>
 	<string name="screen_set_password_strength_indicator_1">Faible</string>
 	<string name="screen_set_password_strength_indicator_2">Acceptable</string>
 	<string name="screen_set_password_strength_indicator_3">Fort</string>

presentation/src/main/res/values-he/strings.xml

@@ -14,6 +14,7 @@
 	<!-- ## screen: choose cloud service -->
 	<!-- ## screen: cloud connections -->
 	<!-- ## screen: webdav settings -->
+	<!-- ## screen: s3 settings -->
 	<!-- ## screen: enter vault name -->
 	<!-- ## screen: set password -->
 	<!-- ## screen: settings -->

presentation/src/main/res/values-pl/strings.xml

@@ -117,6 +117,7 @@
 	<string name="screen_webdav_settings_msg_url_is_invalid">Adres URL jest nieprawidłowy.</string>
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">Login nie może być pusty.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">Hasło nie może być puste.</string>
+	<!-- ## screen: s3 settings -->
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_msg_name_empty">Nazwa sejfu nie może być pusta.</string>
 	<string name="screen_enter_vault_name_vault_label">Nazwa sejfu</string>
@@ -127,7 +128,6 @@
 	<string name="screen_set_password_button_text">Gotowe</string>
 	<string name="screen_set_password_hint">WAŻNE: Jeśli zapomnisz hasła, nie ma możliwości odzyskania danych.</string>
 	<string name="screen_set_password_retype_password_label">Wpisz hasło ponownie</string>
-	<string name="screen_set_password_strength_indicator_0">Bardzo słabe</string>
 	<string name="screen_set_password_strength_indicator_1">Słabe</string>
 	<string name="screen_set_password_strength_indicator_2">Średnie</string>
 	<string name="screen_set_password_strength_indicator_3">Mocne</string>

presentation/src/main/res/values-sr/strings.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+	<!-- # app -->
+	<!-- # error messages -->
+	<!-- # clouds -->
+	<!-- ## cloud names -->
+	<!-- # permission -->
+	<!-- ## permission messages -->
+	<!-- # screens -->
+	<!-- # screen: vault list -->
+	<!-- # screen: file browser -->
+	<!-- ## screen: text editor -->
+	<!-- ## screen: share files -->
+	<!-- ## screen: choose cloud service -->
+	<!-- ## screen: cloud connections -->
+	<!-- ## screen: webdav settings -->
+	<!-- ## screen: s3 settings -->
+	<!-- ## screen: enter vault name -->
+	<!-- ## screen: set password -->
+	<!-- ## screen: settings -->
+	<!-- ## screen: cloud settings -->
+	<!-- ## screen: licenses -->
+	<!-- ## screen: authenticate cloud -->
+	<!-- ## screen: empty dir file info -->
+	<!-- ## screen: insecure android version info -->
+	<!-- # dialogs -->
+	<!-- Vault not found -->
+	<!-- # error reports -->
+	<!-- # misc -->
+	<!-- ## file size helper -->
+	<!-- ## date helper -->
+	<!-- ## biometric authentication -->
+	<!-- notification -->
+	<!-- lock timeout names -->
+	<!-- cache size names -->
+	<!-- screen scheme mode names -->
+	<!-- update interval names -->
+</resources>

presentation/src/main/res/values-tr/strings.xml

@@ -116,6 +116,7 @@
 	<string name="screen_webdav_settings_msg_url_is_invalid">URL geçersiz.</string>
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">Kullanıcı adı boş olamaz.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">Parola boş olamaz.</string>
+	<!-- ## screen: s3 settings -->
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_msg_name_empty">Kasa adı boş olamaz.</string>
 	<string name="screen_enter_vault_name_vault_label">Kasa adı</string>
@@ -126,7 +127,6 @@
 	<string name="screen_set_password_button_text">Bitti</string>
 	<string name="screen_set_password_hint">ÖNEMLİ UYARI: Parolanızı unutursanız, verilerinizi kurtarmanın herhangi bir yolu yoktur.</string>
 	<string name="screen_set_password_retype_password_label">Yeni şifreyi tekrar yazın</string>
-	<string name="screen_set_password_strength_indicator_0">Çok zayıf</string>
 	<string name="screen_set_password_strength_indicator_1">Güçsüz</string>
 	<string name="screen_set_password_strength_indicator_2">Makul</string>
 	<string name="screen_set_password_strength_indicator_3">Kuvvetli</string>

presentation/src/main/res/values/strings.xml

@@ -33,6 +33,7 @@
 	<string name="error_play_services_not_available">Play Services not installed</string>
 	<string name="error_biometric_auth_aborted">Biometric authentication aborted</string>
 	<string name="error_file_not_found_after_opening_using_3party">Local file isn\'t present anymore after switching back to Cryptomator. Possible changes cannot be propagated back to the cloud.</string>
+	<string name="error_no_such_bucket">No such bucket</string>
 
 	<!-- # clouds -->
 
@@ -43,6 +44,7 @@
 	<string name="cloud_names_onedrive" translatable="false">OneDrive</string>
 	<string name="cloud_names_pcloud" translatable="false">pCloud</string>
 	<string name="cloud_names_webdav" translatable="false">WebDAV</string>
+	<string name="cloud_names_s3" translatable="false">S3</string>
 	<string name="cloud_names_local_storage">Local storage</string>
 
 	<!-- # permission -->
@@ -172,6 +174,22 @@
 	<string name="screen_webdav_settings_msg_username_must_not_be_empty">Username can\'t be empty.</string>
 	<string name="screen_webdav_settings_msg_password_must_not_be_empty">Password can\'t be empty.</string>
 
+	<!-- ## screen: s3 settings -->
+	<string name="screen_s3_settings_title" translatable="false">@string/cloud_names_s3</string>
+	<string name="screen_s3_settings_display_name_label">Display Name</string>
+	<string name="screen_s3_settings_access_key_label">Access Key</string>
+	<string name="screen_s3_settings_secret_key_label">Secret Key</string>
+	<string name="screen_s3_settings_bucket_label">Existing Bucket</string>
+	<string name="screen_s3_settings_endpoint_label">Endpoint</string>
+	<string name="screen_s3_settings_region_label">Region</string>
+	<string name="screen_s3_settings_amazon_s3_text" translatable="false">Amazon S3</string>
+
+	<string name="screen_s3_settings_msg_display_name_not_empty">Display Name can\'t be empty</string>
+	<string name="screen_s3_settings_msg_access_key_not_empty">Access Key can\'t be empty</string>
+	<string name="screen_s3_settings_msg_secret_key_not_empty">Secret Key can\'t be empty</string>
+	<string name="screen_s3_settings_msg_bucket_not_empty">Bucket can\'t be empty</string>
+	<string name="screen_s3_settings_msg_endpoint_and_region_not_empty">Endpoint and Region can\'t be empty</string>
+
 	<!-- ## screen: enter vault name -->
 	<string name="screen_enter_vault_name_title" translatable="false">@string/screen_vault_list_action_create_new_vault</string>
 	<string name="screen_enter_vault_name_msg_name_empty">Vault name can\'t be empty.</string>
@@ -187,7 +205,7 @@
 	<string name="screen_set_password_password_label" translatable="false">@string/screen_webdav_settings_password_label</string>
 	<string name="screen_set_password_retype_password_label">Retype password</string>
 
-	<string name="screen_set_password_strength_indicator_0">Very weak</string>
+	<string name="screen_set_password_strength_indicator_0">Too weak to create a vault</string>
 	<string name="screen_set_password_strength_indicator_1">Weak</string>
 	<string name="screen_set_password_strength_indicator_2">Fair</string>
 	<string name="screen_set_password_strength_indicator_3">Strong</string>
@@ -257,6 +275,7 @@
 	<string name="screen_cloud_settings_title" translatable="false">@string/screen_settings_cloud_settings_label</string>
 	<string name="screen_cloud_settings_webdav_connections">WebDAV connections</string>
 	<string name="screen_cloud_settings_pcloud_connections">pCloud connections</string>
+	<string name="screen_cloud_settings_s3_connections">S3 connections</string>
 	<string name="screen_cloud_settings_local_storage_locations">Local storage locations</string>
 	<string name="screen_cloud_settings_log_in_to">Log in to</string>
 	<string name="screen_cloud_settings_sign_out_from_cloud">Sign out from</string>

presentation/src/main/res/xml/licenses.xml

@@ -134,6 +134,13 @@
 				android:action="android.intent.action.VIEW"
 				android:data="https://github.com/ReactiveX/RxJava" />
 		</Preference>
+		<Preference
+			android:summary="Apache License v2"
+			android:title="AWS SDK for Android">
+			<intent
+				android:action="android.intent.action.VIEW"
+				android:data="https://github.com/aws-amplify/aws-sdk-android" />
+		</Preference>
 		<Preference
 			android:summary="Apache License v2"
 			android:title="Subsampling Scale Image View">

presentation/src/notFoss/java/org/cryptomator/presentation/presenter/AuthenticateCloudPresenter.kt

@@ -40,10 +40,12 @@ import org.cryptomator.presentation.R
 import org.cryptomator.presentation.exception.ExceptionHandlers
 import org.cryptomator.presentation.exception.PermissionNotGrantedException
 import org.cryptomator.presentation.intent.AuthenticateCloudIntent
+import org.cryptomator.presentation.intent.Intents
 import org.cryptomator.presentation.model.CloudModel
 import org.cryptomator.presentation.model.CloudTypeModel
 import org.cryptomator.presentation.model.ProgressModel
 import org.cryptomator.presentation.model.ProgressStateModel
+import org.cryptomator.presentation.model.S3CloudModel
 import org.cryptomator.presentation.model.WebDavCloudModel
 import org.cryptomator.presentation.model.mappers.CloudModelMapper
 import org.cryptomator.presentation.ui.activity.view.AuthenticateCloudView
@@ -76,6 +78,7 @@ class AuthenticateCloudPresenter @Inject constructor( //
 			OnedriveAuthStrategy(),  //
 			PCloudAuthStrategy(), //
 			WebDAVAuthStrategy(),  //
+			S3AuthStrategy(), //
 			LocalStorageAuthStrategy() //
 	)
 
@@ -448,6 +451,38 @@ class AuthenticateCloudPresenter @Inject constructor( //
 		finish()
 	}
 
+	private inner class S3AuthStrategy : AuthStrategy {
+
+		private var authenticationStarted = false
+
+		override fun supports(cloud: CloudModel): Boolean {
+			return cloud.cloudType() == CloudTypeModel.S3
+		}
+
+		override fun resumed(intent: AuthenticateCloudIntent) {
+			when {
+				ExceptionUtil.contains(intent.error(), WrongCredentialsException::class.java) -> {
+					if (!authenticationStarted) {
+						startAuthentication(intent.cloud())
+						Toast.makeText(
+								context(),
+								String.format(getString(R.string.error_authentication_failed), intent.cloud().username()),
+								Toast.LENGTH_LONG).show()
+					}
+				}
+				else -> {
+					Timber.tag("AuthicateCloudPrester").e(intent.error())
+					failAuthentication(intent.cloud().name())
+				}
+			}
+		}
+
+		private fun startAuthentication(cloud: CloudModel) {
+			authenticationStarted = true
+			startIntent(Intents.s3AddOrChangeIntent().withS3Cloud(cloud as S3CloudModel))
+		}
+	}
+
 	private inner class LocalStorageAuthStrategy : AuthStrategy {
 
 		private var authenticationStarted = false

util/src/main/java/org/cryptomator/util/file/LruFileCacheUtil.kt

@@ -21,7 +21,7 @@ class LruFileCacheUtil(context: Context) {
 	private val parent: File = context.cacheDir
 
 	enum class Cache {
-		DROPBOX, WEBDAV, PCLOUD, ONEDRIVE, GOOGLE_DRIVE
+		DROPBOX, WEBDAV, PCLOUD, S3, ONEDRIVE, GOOGLE_DRIVE
 	}
 
 	fun resolve(cache: Cache?): File {
@@ -29,6 +29,7 @@ class LruFileCacheUtil(context: Context) {
 			Cache.DROPBOX -> File(parent, "LruCacheDropbox")
 			Cache.WEBDAV -> File(parent, "LruCacheWebdav")
 			Cache.PCLOUD -> File(parent, "LruCachePCloud")
+			Cache.S3 -> File(parent, "LruCacheS3")
 			Cache.ONEDRIVE -> File(parent, "LruCacheOneDrive")
 			Cache.GOOGLE_DRIVE -> File(parent, "LruCacheGoogleDrive")
 			else -> throw IllegalStateException()