Merge pull request #2386 from hyproman/bug-2366-WIP-ssh-custom-alg-cfg

Bug 2366 SSH Custom Algorithms Configuration

src/KeePassLib2Android/Kp2aLog.cs

@@ -58,12 +58,12 @@ namespace keepass2android
 
 		}
 
-		private static string LogFilename
+		public static string LogFilename
 		{
 			get { return Application.Context.FilesDir.CanonicalPath +"/keepass2android.log"; }
 		}
 
-		private static bool LogToFile
+		public static bool LogToFile
 		{
 			get
 			{

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/JavaFileStorage.java

@@ -97,7 +97,28 @@ public class FileEntry {
 			return false;
 		return true;
 	}
-	
+
+	@Override
+	public String toString() {
+		StringBuilder s = new StringBuilder("JavaFileStorage.FileEntry{").append(displayName).append("|")
+				.append("path=").append(path).append(",sz=").append(sizeInBytes)
+				.append(",").append(isDirectory ? "dir" : "file")
+				.append(",lastMod=").append(lastModifiedTime);
+
+		StringBuilder perms = new StringBuilder();
+		if (canRead)
+			perms.append("r");
+		if (canWrite)
+			perms.append("w");
+		if (perms.length() > 0) {
+			s.append(",").append(perms);
+		}
+
+		if (userData != null && userData.length() > 0)
+			s.append(",userData=").append(userData);
+
+		return s.append("}").toString();
+	}
 	
 }
 	

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/Kp2aJSchLogger.java

@@ -0,0 +1,101 @@
+package keepass2android.javafilestorage;
+
+import android.util.Log;
+
+import com.jcraft.jsch.Logger;
+
+import java.io.FileWriter;
+import java.io.PrintWriter;
+import java.util.Map;
+
+public class Kp2aJSchLogger implements Logger {
+
+    private static final String PREFIX = "KP2AJFS[JSch]";
+
+    private interface ILogger {
+        void log(String message);
+    }
+
+    private interface EntryToLogFactory {
+        ILogger create(LogEntry e);
+    }
+
+    private static final EntryToLogFactory ANDROID_FACTORY = e -> e.logger;
+
+    private static final class LogEntry {
+        private final String levelTag;
+        private final ILogger logger;
+
+        LogEntry(String levelTag, ILogger logger) {
+            this.levelTag = levelTag;
+            this.logger = logger;
+        }
+    }
+    private static final ILogger DEBUG = msg -> Log.d(PREFIX, msg);
+    private static final LogEntry DEBUG_ENTRY = new LogEntry("D", DEBUG);
+    private static final ILogger ERROR = msg -> Log.e(PREFIX, msg);
+    private static final LogEntry DEFAULT_ENTRY = DEBUG_ENTRY;
+
+    private static final Map<Integer, LogEntry> loggers = Map.of(
+            Logger.DEBUG, DEBUG_ENTRY,
+            Logger.INFO, new LogEntry("I", msg -> Log.i(PREFIX, msg)),
+            Logger.WARN, new LogEntry("W", msg -> Log.w(PREFIX, msg)),
+            Logger.ERROR, new LogEntry("E", ERROR),
+            Logger.FATAL, new LogEntry("F", msg -> Log.wtf(PREFIX, msg))
+    );
+
+
+    private final EntryToLogFactory logFactory;
+
+    static Kp2aJSchLogger createAndroidLogger() {
+        return new Kp2aJSchLogger(ANDROID_FACTORY);
+    }
+
+    static Kp2aJSchLogger createFileLogger(String logFilename) {
+        final String fName = logFilename;
+        return new Kp2aJSchLogger(e -> createFileLogger(e, fName));
+    }
+
+    private Kp2aJSchLogger(EntryToLogFactory logFactory) {
+        this.logFactory = logFactory;
+    }
+
+    @Override
+    public boolean isEnabled(int level) {
+        return true;
+    }
+
+    @Override
+    public void log(int level, String message) {
+        if (isEnabled(level))
+            getLogger(level).log(message);
+    }
+
+    private ILogger getLogger(int level) {
+        LogEntry entry = loggers.get(level);
+        if (entry == null)
+            entry = DEFAULT_ENTRY;
+
+        return logFactory.create(entry);
+    }
+
+    private static ILogger createFileLogger(LogEntry entry, String fName) {
+        try {
+            final PrintWriter p = new PrintWriter(new FileWriter(fName, true));
+            return msg -> {
+                try {
+                    String fullMsg = String.join(" ", entry.levelTag, PREFIX, msg);
+                    p.println(fullMsg);
+                } catch (Exception e) {
+                    ERROR.log(e.getMessage());
+                } finally {
+                    p.close();
+                }
+            };
+        } catch (Exception e) {
+            ERROR.log(e.getMessage());
+            return entry.logger;
+        }
+    }
+}
+

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/SftpPublicPrivateKeyUtils.java

@@ -0,0 +1,216 @@
+package keepass2android.javafilestorage;
+
+import android.util.Pair;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.regex.Pattern;
+
+import androidx.annotation.Nullable;
+
+import com.jcraft.jsch.JSch;
+import com.jcraft.jsch.JSchException;
+import com.jcraft.jsch.KeyPair;
+
+class SftpPublicPrivateKeyUtils {
+
+    private enum Validity {
+        NOT_ATTEMPTED, VALID, NOT_VALID;
+    }
+
+    private static final String SFTP_CUSTOM_KEY_DIRNAME = "user_keys";
+
+    private static final String KP2A_PRIVATE_KEY_FILENAME = "id_kp2a_rsa";
+
+    private final File appBaseDir;
+
+    /**
+     * Do NOT access this variable directly! Use {@link #baseDir()} instead.
+     */
+    private final File customKeyBaseDir;
+    private volatile Validity validDir = Validity.NOT_ATTEMPTED;
+
+    SftpPublicPrivateKeyUtils(String appBaseDir) {
+        // Assume app base directory exists already
+        this.appBaseDir = new File(appBaseDir);
+
+        // Intentionally skipping existence/creation checking in constructor
+        // See baseDir()
+        this.customKeyBaseDir = new File(appBaseDir, SFTP_CUSTOM_KEY_DIRNAME);
+    }
+
+    private Pair<File, Boolean> baseDir() {
+        if (validDir == Validity.NOT_ATTEMPTED) {
+            synchronized (this) {
+                if (!customKeyBaseDir.exists()) {
+                    customKeyBaseDir.mkdirs();
+                }
+                if (customKeyBaseDir.exists() && customKeyBaseDir.isDirectory()) {
+                    validDir = Validity.VALID;
+                } else {
+                    validDir = Validity.NOT_VALID;
+                }
+            }
+        }
+        return new Pair<>(customKeyBaseDir, validDir == Validity.VALID);
+    }
+
+    boolean deleteCustomKey(String keyName) throws FileNotFoundException {
+        File f = getCustomKeyFile(keyName);
+        return f.isFile() && f.delete();
+    }
+
+    String[] getCustomKeyNames() {
+        Pair<File, Boolean> base = baseDir();
+        if (!base.second) {
+            // Log it?
+            return new String[]{};
+        }
+        return base.first.list();
+    }
+
+    void savePrivateKeyContent(String keyName, String keyContent) throws IOException, Exception {
+        keyContent = PrivateKeyValidator.ensureValidContent(keyContent);
+
+        File f = getCustomKeyFile(keyName);
+        try (BufferedWriter w = new BufferedWriter(new FileWriter(f))) {
+            w.write(keyContent);
+        }
+    }
+
+    String getCustomKeyFilePath(String customKeyName) throws FileNotFoundException {
+        return getCustomKeyFile(customKeyName).getAbsolutePath();
+    }
+
+    String resolveKeyFilePath(JSch jschInst, @Nullable String customKeyName) {
+        // Custom private key configured
+        if (customKeyName != null) {
+            try {
+                return getCustomKeyFilePath(customKeyName);
+            } catch (FileNotFoundException e) {
+                System.out.println(e);
+            }
+        }
+        // Use KP2A's public/private key
+        String keyFilePath = getAppKeyFileName();
+        try{
+            createKeyPair(jschInst, keyFilePath);
+        } catch (Exception ex) {
+            System.out.println(ex);
+        }
+        return keyFilePath;
+    }
+
+    String createKeyPair(JSch jschInst) throws IOException, JSchException {
+        return createKeyPair(jschInst, getAppKeyFileName());
+    }
+
+    /**
+     * Exposed for testing purposes only
+     * @param keyName
+     * @return
+     */
+    String getSanitizedCustomKeyName(String keyName) {
+        return PrivateKeyValidator.sanitizeKeyAsFilename(keyName);
+    }
+
+    /**
+     * Exposed for testing purposes only.
+     * @param keyContent
+     * @return
+     * @throws Exception
+     */
+    String getValidatedCustomKeyContent(String keyContent) throws Exception {
+        return PrivateKeyValidator.ensureValidContent(keyContent);
+    }
+
+    private String createKeyPair(JSch jschInst, String key_filename) throws JSchException, IOException {
+        String public_key_filename = key_filename + ".pub";
+        File file = new File(key_filename);
+        if (file.exists())
+            return public_key_filename;
+        int type = KeyPair.RSA;
+        KeyPair kpair = KeyPair.genKeyPair(jschInst, type, 4096);
+        kpair.writePrivateKey(key_filename);
+
+        kpair.writePublicKey(public_key_filename, "generated by Keepass2Android");
+        //ret = "Fingerprint: " + kpair.getFingerPrint();
+        kpair.dispose();
+        return public_key_filename;
+    }
+
+    private String getAppKeyFileName() {
+        return new File(appBaseDir, KP2A_PRIVATE_KEY_FILENAME).getAbsolutePath();
+    }
+
+    private File getCustomKeyFile(String customKeyName) throws FileNotFoundException {
+        Pair<File, Boolean> base = baseDir();
+        if (!base.second) {
+            throw new FileNotFoundException("Custom key directory");
+        }
+
+        String keyFileName = PrivateKeyValidator.sanitizeKeyAsFilename(customKeyName);
+        if (!keyFileName.isEmpty()) {
+            File keyFile = new File(base.first, keyFileName);
+            // Protect against bad actors trying to navigate away from the base directory.
+            // This is probably overkill, given sanitizeKeyAsFilename(...) but better safe than sorry.
+            if (base.first.equals(keyFile.getParentFile())) {
+                return keyFile;
+            }
+        }
+        // The key was sanitized to nothing, or the parent check above failed.
+        throw new FileNotFoundException("Malformed key name");
+    }
+
+
+    private static class PrivateKeyValidator {
+        private static final Pattern CONTENT_FIRST_LINE = Pattern.compile("^-+BEGIN\\s[^\\s]+\\sPRIVATE\\sKEY-+$");
+        private static final Pattern CONTENT_LAST_LINE = Pattern.compile("^-+END\\s[^\\s]+\\sPRIVATE\\sKEY-+$");
+
+        /**
+         * Key-to-filename sanitizer solution sourced from:
+         *  <a href="https://www.b4x.com/android/forum/threads/sanitize-filename.82558/" />
+         */
+        private static final Pattern KEY_SANITIZER = Pattern.compile("([^\\p{L}\\s\\d\\-_~,;:\\[\\]\\(\\).'])",
+                Pattern.CASE_INSENSITIVE);
+
+        static String sanitizeKeyAsFilename(String key) {
+            return KEY_SANITIZER.matcher(key.trim()).replaceAll("");
+        }
+
+        static String ensureValidContent(String content) throws Exception {
+            content = content.trim();
+
+            boolean isValid = true;
+            try (BufferedReader r = new BufferedReader(new StringReader(content))) {
+                boolean validFirst = false;
+                String line;
+                String last = null;
+                while ((line = r.readLine()) != null) {
+                    if (!validFirst) {
+                        if (CONTENT_FIRST_LINE.matcher(line).matches()) {
+                            validFirst = true;
+                        } else {
+                            isValid = false;
+                            break;
+                        }
+                    }
+                    last = line;
+                }
+                if (!isValid || last == null || !CONTENT_LAST_LINE.matcher(last).matches()) {
+                    throw new RuntimeException("Malformed private key content");
+                }
+            } catch (Exception e) {
+                android.util.Log.d(SftpStorage.class.getName(), "Invalid key content", e);
+                throw e;
+            }
+
+            return content;
+        }
+    }
+}

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/SftpStorage.java

@@ -2,20 +2,24 @@ package keepass2android.javafilestorage;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
 
 import com.jcraft.jsch.Channel;
 import com.jcraft.jsch.ChannelSftp;
 import com.jcraft.jsch.ChannelSftp.LsEntry;
 import com.jcraft.jsch.JSch;
 import com.jcraft.jsch.JSchException;
-import com.jcraft.jsch.KeyPair;
+import com.jcraft.jsch.Logger;
 import com.jcraft.jsch.Session;
 import com.jcraft.jsch.SftpATTRS;
 import com.jcraft.jsch.SftpException;
@@ -26,10 +30,38 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
 
+@SuppressWarnings("unused")  // Exposed by JavaFileStorageBindings
 public class SftpStorage extends JavaFileStorageBase {
+	@FunctionalInterface
+	interface ValueResolver<T> {
+		/**
+		 * Takes a raw value and resolves it to either a String containing the String representation
+		 * of that value, or null. The latter signifying that the raw value could not be "resolved".
+		 *
+		 * @param value
+		 * @return String, or null if not resolvable
+		 */
+		String resolve(T value);
+	}
 
 	public static final int DEFAULT_SFTP_PORT = 22;
-	JSch jsch;
+	public static final int UNSET_SFTP_CONNECT_TIMEOUT = -1;
+	private static final String SFTP_CONNECT_TIMEOUT_OPTION_NAME = "connectTimeout";
+	private static final String SFTP_KEYNAME_OPTION_NAME = "key";
+	private static final String SFTP_KEYPASSPHRASE_OPTION_NAME = "phrase";
+
+	public static final String SSH_CFG_KEX = "kex";
+	public static final String SSH_CFG_SERVER_HOST_KEY = "server_host_key";
+	private static final Set<String> SSH_CFG_CSV_EXPANDABLE = Set.of(SSH_CFG_KEX, SSH_CFG_SERVER_HOST_KEY);
+	private static final ValueResolver<Integer> cTimeoutResolver = c ->
+			c == null || c == UNSET_SFTP_CONNECT_TIMEOUT ? null : String.valueOf(c);
+
+	private static final ValueResolver<String> nonBlankStringResolver = s ->
+			s == null || s.isBlank() ? null : s;
+
+	private static final String TAG = "KP2AJFS";
+	private static final String THREAD_TAG = TAG + "[thread]";
+	private JSch jsch;
 
 	public class ConnectionInfo
 	{
@@ -37,13 +69,42 @@ public class SftpStorage extends JavaFileStorageBase {
 		public String username;
 		public String password;
 		public String localPath;
+		public String keyName;
+		public String keyPassphrase;
 		public int port;
+		public int connectTimeoutSec = UNSET_SFTP_CONNECT_TIMEOUT;
+		public final Map<String, String> configOpts = new HashMap<>();
+
+
+		public String toString() {
+			return "ConnectionInfo{host=" + host + ",port=" + port + ",user=" + username +
+					",pwd=<hidden>,localPath=" + localPath + ",key=" + keyName +
+					",phrase=<hidden>,connectTimeout=" + connectTimeoutSec +
+					",cfgOpts=" + configOpts +
+					"}";
+		}
 	}
+
+	private static Map<String, String> buildOptionMap(ConnectionInfo ci, boolean includeSensitive) {
+		OptionMapBuilder b = new OptionMapBuilder()
+				.addOption(SFTP_CONNECT_TIMEOUT_OPTION_NAME, ci.connectTimeoutSec, cTimeoutResolver)
+				.addOption(SFTP_KEYNAME_OPTION_NAME, ci.keyName, nonBlankStringResolver);
+		// Assume all config options are not sensitive and use the same resolver...
+		for (Map.Entry<String, String> entry : ci.configOpts.entrySet()) {
+			b.addOption(entry.getKey(), entry.getValue(), nonBlankStringResolver);
+		}
+		if (includeSensitive) {
+			b.addOption(SFTP_KEYPASSPHRASE_OPTION_NAME, ci.keyPassphrase, nonBlankStringResolver);
+		}
+		return b.build();
+	}
+
 	Context _appContext;
+	private final SftpPublicPrivateKeyUtils _keyUtils;
 
 	public SftpStorage(Context appContext) {
 		_appContext = appContext;
-
+		_keyUtils = new SftpPublicPrivateKeyUtils(getBaseDir());
 	}
 
 	private static final String SFTP_PROTOCOL_ID = "sftp";
@@ -65,15 +126,15 @@ public class SftpStorage extends JavaFileStorageBase {
 
 	@Override
 	public InputStream openFileForRead(String path) throws Exception {
-
-		ChannelSftp c = init(path);
+		ConnectionInfo cInfo = splitStringToConnectionInfo(path);
+		ChannelSftp c = init(cInfo);
 
 		try {
 			byte[] buff = new byte[8000];
 
 			int bytesRead = 0;
 
-			InputStream in = c.get(extractSessionPath(path));
+			InputStream in = c.get(cInfo.localPath);
 			ByteArrayOutputStream bao = new ByteArrayOutputStream();
 
 			while ((bytesRead = in.read(buff)) != -1) {
@@ -105,14 +166,15 @@ public class SftpStorage extends JavaFileStorageBase {
 	public void uploadFile(String path, byte[] data, boolean writeTransactional)
 			throws Exception {
 
-		ChannelSftp c = init(path);
+		ConnectionInfo cInfo = splitStringToConnectionInfo(path);
+		ChannelSftp c = init(cInfo);
 		try {
 			InputStream in = new ByteArrayInputStream(data);
-			String targetPath = extractSessionPath(path);
+			String targetPath = cInfo.localPath;
 			if (writeTransactional)
 			{
 				//upload to temporary location:
-				String tmpPath = targetPath+".tmp";
+				String tmpPath = targetPath + ".tmp";
 				c.put(in, tmpPath);
 				//remove previous file:
 				try
@@ -128,9 +190,9 @@ public class SftpStorage extends JavaFileStorageBase {
 			}
 			else
 			{
-				c.put(in, targetPath);				
+				c.put(in, targetPath);
 			}
-			
+
 			tryDisconnect(c);
 		} catch (Exception e) {
 			tryDisconnect(c);
@@ -142,53 +204,98 @@ public class SftpStorage extends JavaFileStorageBase {
 	@Override
 	public String createFolder(String parentPath, String newDirName)
 			throws Exception {
-
+		ConnectionInfo cInfo = splitStringToConnectionInfo(parentPath);
 		try {
-			ChannelSftp c = init(parentPath);
-			String newPath = concatPaths(parentPath, newDirName);
-			c.mkdir(extractSessionPath(newPath));
+			ChannelSftp c = init(cInfo);
+			String newPath = concatPaths(cInfo.localPath, newDirName);
+			c.mkdir(newPath);
 			tryDisconnect(c);
-			return newPath;
+
+			return buildFullPath(cInfo.host, cInfo.port, newPath,
+					cInfo.username, cInfo.password, cInfo.connectTimeoutSec,
+					cInfo.keyName, cInfo.keyPassphrase,
+					cInfo.configOpts.get(SSH_CFG_KEX),
+					cInfo.configOpts.get(SSH_CFG_SERVER_HOST_KEY));
 		} catch (Exception e) {
 			throw convertException(e);
 		}
 
 	}
 
+	private String extractUserPwdHostPort(String path) {
+	    String withoutProtocol = path
+				.substring(getProtocolPrefix().length());
+		return withoutProtocol.substring(0, withoutProtocol.indexOf("/"));
+	}
+
 	private String extractSessionPath(String newPath) {
 		String withoutProtocol = newPath
 				.substring(getProtocolPrefix().length());
-		return withoutProtocol.substring(withoutProtocol.indexOf("/"));
+		int pathStartIdx = withoutProtocol.indexOf("/");
+		int pathEndIdx = withoutProtocol.indexOf("?");
+		if (pathEndIdx < 0) {
+			pathEndIdx = withoutProtocol.length();
+		}
+		return withoutProtocol.substring(pathStartIdx, pathEndIdx);
 	}
-	
-	private String extractUserPwdHost(String path) {
+
+	private Map<String, String> extractOptionsMap(String path) throws UnsupportedEncodingException {
 		String withoutProtocol = path
 				.substring(getProtocolPrefix().length());
-		return withoutProtocol.substring(0,withoutProtocol.indexOf("/"));
+
+		Map<String, String> options = new HashMap<>();
+
+		int extraOptsIdx = withoutProtocol.indexOf("?");
+		if (extraOptsIdx > 0 && extraOptsIdx + 1 < withoutProtocol.length()) {
+			String optsString = withoutProtocol.substring(extraOptsIdx + 1);
+			String[] parts = optsString.split("&");
+			for (String p : parts) {
+				int sepIdx = p.indexOf('=');
+				if (sepIdx > 0) {
+					String key = decode(p.substring(0, sepIdx));
+					String value = decode(p.substring(sepIdx + 1));
+					options.put(key, value);
+				} else {
+					options.put(decode(p), "true");
+				}
+			}
+		}
+		return options;
 	}
 
 	private String concatPaths(String parentPath, String newDirName) {
-		String res = parentPath;
-		if (!res.endsWith("/"))
-			res += "/";
-		res += newDirName;
-		return res;
+		StringBuilder fp = new StringBuilder(parentPath);
+		if (!parentPath.endsWith("/"))
+			fp.append("/");
+		return fp.append(newDirName).toString();
 	}
 
 	@Override
-	public String createFilePath(String parentPath, String newFileName)
+	public String createFilePath(final String parentUri, String newFileName)
 			throws Exception {
-		if (parentPath.endsWith("/") == false)
-			parentPath += "/";
-		return parentPath + newFileName;
+
+		String parentPath = parentUri;
+		String params = null;
+		int paramsIdx = parentUri.lastIndexOf("?");
+		if (paramsIdx > 0) {
+			params = parentUri.substring(paramsIdx);
+			parentPath = parentPath.substring(0, paramsIdx);
+		}
+
+		String newPath = concatPaths(parentPath, newFileName);
+
+		if (params != null) {
+			newPath += params;
+		}
+		return newPath;
 	}
 
 	@Override
 	public List<FileEntry> listFiles(String parentPath) throws Exception {
+		ConnectionInfo cInfo = splitStringToConnectionInfo(parentPath);
+		ChannelSftp c = init(cInfo);
 
-		ChannelSftp c = init(parentPath);
 		return listFiles(parentPath, c);
-
 	}
 
 	private void setFromAttrs(FileEntry fileEntry, SftpATTRS attrs) {
@@ -212,23 +319,27 @@ public class SftpStorage extends JavaFileStorageBase {
 			if (sftpEx.id == ChannelSftp.SSH_FX_NO_SUCH_FILE)
 				return new FileNotFoundException(sftpEx.getMessage());
 		}
-		
+
 		return e;
 
 	}
 
 	@Override
 	public FileEntry getFileEntry(String filename) throws Exception {
-
-		ChannelSftp c = init(filename);
+		ConnectionInfo cInfo = splitStringToConnectionInfo(filename);
+		ChannelSftp c = init(cInfo);
 		try {
 			FileEntry fileEntry = new FileEntry();
-			String sessionPath = extractSessionPath(filename);
-			SftpATTRS attr = c.stat(sessionPath);
+			SftpATTRS attr = c.stat(cInfo.localPath);
 			setFromAttrs(fileEntry, attr);
+
+			// Full URI
 			fileEntry.path = filename;
-			fileEntry.displayName = getFilename(sessionPath);
+
+			fileEntry.displayName = getFilename(cInfo.localPath);
+
 			tryDisconnect(c);
+
 			return fileEntry;
 		} catch (Exception e) {
 			logDebug("Exception in getFileEntry! " + e);
@@ -239,8 +350,9 @@ public class SftpStorage extends JavaFileStorageBase {
 
 	@Override
 	public void delete(String path) throws Exception {
+		ConnectionInfo cInfo = splitStringToConnectionInfo(path);
+		ChannelSftp c = init(cInfo);
 
-		ChannelSftp c = init(path);
 		delete(path, c);
 	}
 
@@ -264,10 +376,11 @@ public class SftpStorage extends JavaFileStorageBase {
 			tryDisconnect(c);
 			throw convertException(e);
 		}
-		
+
 	}
 
 	private List<FileEntry> listFiles(String path, ChannelSftp c) throws Exception {
+
 		try {
 			List<FileEntry> res = new ArrayList<FileEntry>();
 			@SuppressWarnings("rawtypes")
@@ -283,7 +396,7 @@ public class SftpStorage extends JavaFileStorageBase {
 								||(lsEntry.getFilename().equals(".."))
 								)
 							continue;
-						
+
 						FileEntry fileEntry = new FileEntry();
 						fileEntry.displayName = lsEntry.getFilename();
 						fileEntry.path = createFilePath(path, fileEntry.displayName);
@@ -313,97 +426,161 @@ public class SftpStorage extends JavaFileStorageBase {
 			throws UnsupportedEncodingException {
 		return java.net.URLDecoder.decode(encodedString, UTF_8);
 	}
-	
+
 	@Override
 	protected String encode(final String unencoded)
 			throws UnsupportedEncodingException {
 		return java.net.URLEncoder.encode(unencoded, UTF_8);
 	}
-	
-	ChannelSftp init(String filename) throws JSchException, UnsupportedEncodingException {
-		jsch = new JSch();
-		ConnectionInfo ci = splitStringToConnectionInfo(filename);
 
-		Log.d("KP2AJFS", "init SFTP");
+
+	ChannelSftp init(ConnectionInfo cInfo) throws JSchException, UnsupportedEncodingException {
+		jsch = new JSch();
+
+		Log.d(TAG, "init SFTP");
 
 		String base_dir = getBaseDir();
 		jsch.setKnownHosts(base_dir + "/known_hosts");
 
-		String key_filename = getKeyFileName();
-		try{
-			createKeyPair(key_filename);
-		} catch (Exception ex) {
-			System.out.println(ex);
-		}
+		String key_filepath = _keyUtils.resolveKeyFilePath(jsch, cInfo.keyName);
 
 		try {
-			jsch.addIdentity(key_filename);
-		} catch (java.lang.Exception e)
-		{
+			jsch.addIdentity(key_filepath);
+		} catch (java.lang.Exception e) {
 
 		}
 
-		Log.e("KP2AJFS[thread]", "getting session...");
-		Session session = jsch.getSession(ci.username, ci.host, ci.port);
-		Log.e("KP2AJFS", "creating SftpUserInfo");
-		UserInfo ui = new SftpUserInfo(ci.password,_appContext);
-		session.setUserInfo(ui);
+		Log.e(THREAD_TAG, "getting session...");
+		Session session = jsch.getSession(cInfo.username, cInfo.host, cInfo.port);
 
-		session.setConfig("PreferredAuthentications", "publickey,password");
-
-		session.connect();
+		sessionConfigure(session, cInfo);
+		sessionConnect(session, cInfo);
 
 		Channel channel = session.openChannel("sftp");
 		channel.connect();
 		ChannelSftp c = (ChannelSftp) channel;
 
-		logDebug("success: init Sftp");
 		return c;
 
 	}
 
+	private void sessionConnect(Session session, ConnectionInfo cInfo) throws JSchException {
+		if (cInfo.connectTimeoutSec != UNSET_SFTP_CONNECT_TIMEOUT) {
+			session.connect(cInfo.connectTimeoutSec * 1000);
+		} else {
+			session.connect();
+		}
+	}
+
+	private void sessionConfigure(Session session, ConnectionInfo cInfo) {
+		Log.e(TAG, "creating SftpUserInfo");
+		UserInfo ui = new SftpUserInfo(cInfo.password, cInfo.keyPassphrase, _appContext);
+		session.setUserInfo(ui);
+
+		session.setConfig("PreferredAuthentications", "publickey,password");
+
+		for (Map.Entry<String, String> e : cInfo.configOpts.entrySet()) {
+			String cfgKey = e.getKey();
+			String before = session.getConfig(cfgKey);
+			String after = e.getValue();
+
+			if (SSH_CFG_CSV_EXPANDABLE.contains(cfgKey)) {
+				SshConfigCsvValueResolver resolver = new SshConfigCsvValueResolver(cfgKey, after);
+				after = resolver.resolve(before);
+			}
+			session.setConfig(cfgKey, after);
+		}
+	}
+
 	private String getBaseDir() {
 		return _appContext.getFilesDir().getAbsolutePath();
 	}
 
-	private String getKeyFileName() {
-		return getBaseDir() + "/id_kp2a_rsa";
+	public boolean deleteCustomKey(String keyName) throws FileNotFoundException {
+		return _keyUtils.deleteCustomKey(keyName);
 	}
 
+	public String[] getCustomKeyNames() {
+		return _keyUtils.getCustomKeyNames();
+	}
+
+	@SuppressWarnings("unused")  // Exposed by JavaFileStorageBindings
 	public String createKeyPair() throws IOException, JSchException {
-		return createKeyPair(getKeyFileName());
-
+		return _keyUtils.createKeyPair(jsch);
 	}
 
-	private String createKeyPair(String key_filename) throws JSchException, IOException {
-		String public_key_filename = key_filename + ".pub";
-		File file = new File(key_filename);
-		if (file.exists())
-			return public_key_filename;
-		int type = KeyPair.RSA;
-		KeyPair kpair = KeyPair.genKeyPair(jsch, type, 4096);
-		kpair.writePrivateKey(key_filename);
+	@SuppressWarnings("unused")  // Exposed by JavaFileStorageBindings
+	public void savePrivateKeyContent(String keyName, String keyContent) throws IOException, Exception {
+		_keyUtils.savePrivateKeyContent(keyName, keyContent);
+	}
 
-		kpair.writePublicKey(public_key_filename, "generated by Keepass2Android");
-		//ret = "Fingerprint: " + kpair.getFingerPrint();
-		kpair.dispose();
-		return public_key_filename;
+	@SuppressWarnings("unused")  // Exposed by JavaFileStorageBindings
+	public void setJschLogging(boolean enabled, String logFilename) {
+		Logger impl = null;
+		if (enabled) {
+			if (logFilename != null) {
+				impl = Kp2aJSchLogger.createFileLogger(logFilename);
+			} else {
+				impl = Kp2aJSchLogger.createAndroidLogger();
+			}
+		}
+		JSch.setLogger(impl);
+	}
 
+	/**
+	 * Exposed for testing purposes only.
+	 * @param keyName
+	 * @return
+	 */
+	public String sanitizeCustomKeyName(String keyName) {
+		return _keyUtils.getSanitizedCustomKeyName(keyName);
+	}
+
+	/**
+	 * Exposed for testing purposes only.
+	 * @param keyContent
+	 * @return
+	 * @throws Exception
+	 */
+	public String getValidatedCustomKeyContent(String keyContent) throws Exception {
+		return _keyUtils.getValidatedCustomKeyContent(keyContent);
+	}
+
+	/**
+	 * Exposed for testing purposes only.
+	 * @param currentValues
+	 * @param spec
+	 * @return
+	 * @throws Exception
+	 */
+	public String resolveCsvValues(String currentValues, String spec) {
+		return new SshConfigCsvValueResolver("test", spec)
+				.resolve(currentValues);
 	}
 
 	public ConnectionInfo splitStringToConnectionInfo(String filename)
 			throws UnsupportedEncodingException {
+
 		ConnectionInfo ci = new ConnectionInfo();
-		ci.host = extractUserPwdHost(filename);
+		ci.host = extractUserPwdHostPort(filename);
+
 		String userPwd = ci.host.substring(0, ci.host.indexOf('@'));
-		ci.username = decode(userPwd.substring(0, userPwd.indexOf(":")));
-		ci.password = decode(userPwd.substring(userPwd.indexOf(":")+1));
+		int sepIdx = userPwd.indexOf(":");
+		if (sepIdx > 0) {
+			ci.username = decode(userPwd.substring(0, sepIdx));
+			ci.password = decode(userPwd.substring(sepIdx + 1));
+		} else {
+			ci.username = userPwd;
+			ci.password = null;
+		}
+
 		ci.host = ci.host.substring(ci.host.indexOf('@') + 1);
 		ci.port = DEFAULT_SFTP_PORT;
-		int portSeparatorIndex = ci.host.lastIndexOf(":");
+
+		int portSeparatorIndex = ci.host.lastIndexOf(':');
 		if (portSeparatorIndex >= 0)
 		{
-			ci.port = Integer.parseInt(ci.host.substring(portSeparatorIndex+1));
+			ci.port = Integer.parseInt(ci.host.substring(portSeparatorIndex + 1));
 			ci.host = ci.host.substring(0, portSeparatorIndex);
 		}
 		// Encode/decode required to support IPv6 (colons break host:port parse logic)
@@ -411,6 +588,30 @@ public class SftpStorage extends JavaFileStorageBase {
 		ci.host = decode(ci.host);
 
 		ci.localPath = extractSessionPath(filename);
+
+		Map<String, String> options = extractOptionsMap(filename);
+
+		if (options.containsKey(SFTP_CONNECT_TIMEOUT_OPTION_NAME)) {
+			String optVal = options.get(SFTP_CONNECT_TIMEOUT_OPTION_NAME);
+			try {
+				ci.connectTimeoutSec = Integer.parseInt(optVal);
+			} catch (NumberFormatException nan) {
+				logDebug(SFTP_CONNECT_TIMEOUT_OPTION_NAME + " option not a number: " + optVal);
+			}
+		}
+		if (options.containsKey(SFTP_KEYNAME_OPTION_NAME)) {
+			ci.keyName = options.get(SFTP_KEYNAME_OPTION_NAME);
+		}
+		if (options.containsKey(SFTP_KEYPASSPHRASE_OPTION_NAME)) {
+			ci.keyPassphrase = options.get(SFTP_KEYPASSPHRASE_OPTION_NAME);
+		}
+
+		for (String cfgKey : SSH_CFG_CSV_EXPANDABLE) {
+			if (options.containsKey(cfgKey)) {
+				ci.configOpts.put(cfgKey, options.get(cfgKey));
+			}
+		}
+
 		return ci;
 	}
 
@@ -447,12 +648,18 @@ public class SftpStorage extends JavaFileStorageBase {
 		try
 		{
 			ConnectionInfo ci = splitStringToConnectionInfo(path);
-			return getProtocolPrefix()+ci.username+"@"+ci.host+ci.localPath;
+			StringBuilder dName = new StringBuilder(getProtocolPrefix())
+					.append(ci.username)
+					.append("@")
+					.append(ci.host)
+					.append(ci.localPath);
+			appendOptions(dName, buildOptionMap(ci, false));
+			return dName.toString();
 		}
 		catch (Exception e)
 		{
 			return extractSessionPath(path);
-		}		
+		}
 	}
 
 	@Override
@@ -474,26 +681,105 @@ public class SftpStorage extends JavaFileStorageBase {
 	@Override
 	public void onActivityResult(FileStorageSetupActivity activity,
 			int requestCode, int resultCode, Intent data) {
-		
+
 
 	}
 
-	public String buildFullPath( String host, int port, String localPath, String username, String password) throws UnsupportedEncodingException
-	{
+	public String buildFullPath(String host, int port, String localPath,
+										String username, String password,
+										int connectTimeoutSec,
+										String keyName, String keyPassphrase,
+										String kexAlgorithms, String shkAlgorithms)
+			throws UnsupportedEncodingException {
+
+		StringBuilder uri = new StringBuilder(getProtocolPrefix()).append(encode(username));
+		if (password != null) {
+			uri.append(":").append(encode(password));
+		}
+		uri.append("@");
 		// Encode/decode required to support IPv6 (colons break host:port parse logic)
 		// See Bug #2350
-		host = encode(host);
+		uri.append(encode(host));
 
-		if (port != DEFAULT_SFTP_PORT)
-			host += ":"+String.valueOf(port);
-		return getProtocolPrefix()+encode(username)+":"+encode(password)+"@"+host+localPath;
-		
+		if (port != DEFAULT_SFTP_PORT) {
+			uri.append(":").append(port);
+		}
+		if (localPath != null && localPath.startsWith("/")) {
+			uri.append(localPath);
+		}
+
+		appendOptions(uri, new OptionMapBuilder()
+				.addOption(SFTP_CONNECT_TIMEOUT_OPTION_NAME, connectTimeoutSec, cTimeoutResolver)
+				.addOption(SFTP_KEYNAME_OPTION_NAME, keyName, nonBlankStringResolver)
+				.addOption(SFTP_KEYPASSPHRASE_OPTION_NAME, keyPassphrase, nonBlankStringResolver)
+				.addOption(SSH_CFG_KEX, kexAlgorithms, nonBlankStringResolver)
+				.addOption(SSH_CFG_SERVER_HOST_KEY, shkAlgorithms, nonBlankStringResolver)
+				.build());
+
+		return uri.toString();
+	}
+
+	private void appendOptions(StringBuilder uri, Map<String, String> opts)
+			throws UnsupportedEncodingException {
+
+		boolean first = true;
+		// Sort for stability/consistency
+		Set<Map.Entry<String, String>> sortedEntries = new TreeSet<>(new EntryComparator<>());
+		sortedEntries.addAll(opts.entrySet());
+		for (Map.Entry<String, String> me : sortedEntries) {
+			if (first) {
+				uri.append("?");
+				first = false;
+			} else {
+				uri.append("&");
+			}
+			uri.append(encode(me.getKey())).append("=").append(encode(me.getValue()));
+		}
 	}
 
 
 	@Override
 	public void prepareFileUsage(Context appContext, String path) {
 		//nothing to do
-		
+
+	}
+
+	/**
+	 * A comparator that compares Map.Entry objects by their keys, via natural ordering.
+	 *
+	 * @param <T> the Map.Entry key type, that must implement Comparable.
+	 */
+	private static class EntryComparator<T extends Comparable<T>> implements Comparator<Map.Entry<T, ?>> {
+		@Override
+		public int compare(Map.Entry<T, ?> o1, Map.Entry<T, ?> o2) {
+			return o1.getKey().compareTo(o2.getKey());
+		}
+	}
+
+	private static class OptionMapBuilder {
+		private final Map<String, String> options = new HashMap<>();
+
+		/**
+		 * Attempts to add a raw value <code>oVal</code> to the underlying option map with key <code>oName</code>
+		 * iff the <code>resolver</code> produces a non-null output when invoked using the raw value.
+		 *
+		 * @param oName the name/key associated with the value, if added
+		 * @param oVal the raw value attempting to be added
+		 * @param resolver the resolver that determines if the value will be added
+		 *
+		 * @return OptionMapBuilder (updated)
+		 * @param <T> the raw value type
+		 */
+		<T> OptionMapBuilder addOption(final String oName, T oVal, ValueResolver<T> resolver) {
+			String resolved = resolver.resolve(oVal);
+			if (resolved != null) {
+				options.put(oName, resolved);
+			}
+			return this;
+		}
+
+		Map<String, String> build() {
+			return new HashMap<>(options);
+		}
 	}
 }

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/SftpUserInfo.java

@@ -116,17 +116,19 @@ public class SftpUserInfo implements UserInfo {
 	Context _appContext;
 
 	String _password;
+	String _passphrase;
 	
-	public SftpUserInfo(String password, Context appContext)
+	public SftpUserInfo(String password, String passphrase, Context appContext)
 	{
 		_password = password;
+		_passphrase = passphrase;
 		_appContext = appContext;
 	}
 
 	@Override
 	public String getPassphrase() {
-		
-		return null;
+
+		return _passphrase;
 	}
 
 	@Override
@@ -137,12 +139,12 @@ public class SftpUserInfo implements UserInfo {
 
 	@Override
 	public boolean promptPassword(String message) {
-		return true;
+		return _password != null;
 	}
 
 	@Override
 	public boolean promptPassphrase(String message) {
-		return false; //passphrase not supported
+		return _passphrase != null;
 	}
 
 	@Override

src/java/JavaFileStorage/app/src/main/java/keepass2android/javafilestorage/SshConfigCsvValueResolver.java

@@ -0,0 +1,178 @@
+package keepass2android.javafilestorage;
+
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A class that manipulates CSV String values based on a list of CSV "spec" definitions, where each definition
+ * can describe one of the following:
+ *
+ *   - Prepend to existing list: +something
+ *   - Append to end of existing list: something+
+ *   - Remove a specific value: -something
+ *   - Remove values matching prefix: -something*
+ *   - Remove values matching suffix: -*something
+ *   - Remove values matching substring: -*something*
+ *   - Remove values matching prefix and suffix: -some*thing
+ *
+ *  Otherwise CSV of values completely replace original config values
+ *  
+ *  Examples:
+ *  <code>
+ *    var r = new SshConfigCsvValueResolver("foo", "addToEnd+,-remove*,+addToBeginning,-*del*");
+ *    r.resolve("one,removeTwo,three,removeThree,four") --> "addToBeginning,one,three,four,addToEnd"
+ *    r.resolve("one,my-del,del-me,two,foodelbar,three") --> "addToBeginning,one,two,three,addToEnd"
+ *
+ *    r = new SshConfigCsvValueResolver("foo", "replace,the,config");
+ *    r.resolve("one,two,three,four") --> "replace,the,config"
+ *  </code>
+ *
+ */
+class SshConfigCsvValueResolver {
+    interface Matcher {
+        boolean matches(String s);
+    }
+    private final String cfgKey;
+    private static final String TAG = "KP2AJFS[sshcfg]";
+
+    private static final String DELIM = ",";
+    private static final char ADD = '+';
+    private static final char REMOVE = '-';
+    private static final char WILD = '*';
+    private final List<String> prepends;
+    private final List<String> appends;
+    private final List<Matcher> removes;
+    private final List<String> replaces;
+
+    /**
+     * Creates a new resolver.
+     *
+     * @param cfgKey - configuration key name (used for logging)
+     * @param incomingSpec - A CSV String of "spec" definitions that will be used to
+     *                     (potentially) modify incoming CSV String values.
+     */
+    SshConfigCsvValueResolver(String cfgKey, String incomingSpec) {
+        List<String> prepends = new ArrayList<>();
+        List<String> appends = new ArrayList<>();
+        List<Matcher> removes = new ArrayList<>();
+        List<String> replaces = new ArrayList<>();
+
+        for (String iVal : incomingSpec.split(DELIM)) {
+            if (iVal.isBlank()) {
+                continue;
+            }
+            int evLen = iVal.length();
+            if (iVal.charAt(0) == ADD && evLen > 1) {
+                prepends.add(iVal.substring(1));
+            } else if (iVal.charAt(iVal.length() - 1) == ADD && evLen > 1) {
+                appends.add(iVal.substring(0, evLen - 1));
+            } else if (iVal.charAt(iVal.length() - 1) == REMOVE && evLen > 1) {
+                removes.add(createMatcher(iVal.substring(1)));
+            } else {
+                // This looks like a straight replace
+                replaces.add(iVal);
+            }
+        }
+        this.cfgKey = cfgKey;
+        this.prepends = Collections.unmodifiableList(prepends);
+        this.appends = Collections.unmodifiableList(appends);
+        this.removes = Collections.unmodifiableList(removes);
+        this.replaces = Collections.unmodifiableList(replaces);
+    }
+
+    /**
+     * Takes a CSV String and (potentially) modifies it according to the "spec" entries of this resolver.
+     *
+     * @param existingValues - the original CSV String
+     * @return an updated representation of <code>existingValues</code>, based on the defined "spec"
+     *         entries of this resolver.
+     */
+    public String resolve(String existingValues) {
+        List<String> newValues;
+        // If there's even one replace, it wins over everything and the rest is thrown out
+        if (!replaces.isEmpty()) {
+            if (!(prepends.isEmpty() || appends.isEmpty() || removes.isEmpty())) {
+                Log.w(TAG, "Discarded SSH cfg parts: key=" + cfgKey +
+                        ", prepends=" + prepends + ", appends=" + appends +
+                        ", removes=" + removes);
+            }
+            newValues = replaces;
+        } else {
+            // Otherwise we rebuild from existing and incoming values
+            newValues = createResolvedValues(existingValues);
+        }
+        return String.join(DELIM, newValues);
+    }
+
+    private List<String> createResolvedValues(String existingValues) {
+        List<String> newValues = new ArrayList<>(prepends);
+        for (String a : existingValues.split(DELIM)) {
+            if (!shouldRemove(a)) {
+                newValues.add(a);
+            }
+        }
+        newValues.addAll(appends);
+        return newValues;
+    }
+
+    private boolean shouldRemove(String s) {
+        s = normalize(s);
+        for (Matcher m : removes) {
+            if (m.matches(s)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private Matcher createMatcher(String val) {
+        final String v = normalize(val);
+        Matcher impl = s -> v.equals(s);
+
+        int wildcardIdx = v.indexOf(WILD);
+        if (wildcardIdx < 0) {
+            return impl;
+        }
+
+        // *blah     *blah*     blah*       some*thing
+        // endsWith  substring  startsWith  startsWith && endsWith
+        String subStr = null;
+        String suffix = null;
+        String prefix = null;
+        int vLen = v.length();
+
+        if (v.charAt(0) == WILD && vLen > 1) {
+            if (vLen > 2 && v.charAt(vLen - 1) == WILD) {
+                //substring
+                subStr = v.substring(1, vLen - 1);
+            } else {
+                // endsWith
+                suffix = v.substring(1);
+            }
+        } else if (v.charAt(vLen - 1) == WILD && vLen > 1) {
+            // beginsWith
+            prefix = v.substring(0, v.length() - 1);
+        } else if (wildcardIdx > 0) {
+            // startsWith && endsWith
+            prefix = v.substring(0, wildcardIdx);
+            suffix = v.substring(wildcardIdx + 1);
+        }
+
+        if (subStr != null) {
+            final String sub = subStr;
+            impl = s -> s.contains(sub);
+        } else if (prefix != null || suffix != null) {
+            final String pre = prefix;
+            final String suf = suffix;
+            impl = s -> (pre == null || s.startsWith(pre)) && (suf == null || s.endsWith(suf));
+        }
+        return impl;
+    }
+
+    private static String normalize(String s) {
+        return s == null ? null : s.toLowerCase();
+    }
+}

src/java/JavaFileStorageTest-AS/app/src/main/java/com/crocoapps/javafilestoragetest2/MainActivity.java

@@ -538,12 +538,12 @@ public class MainActivity extends Activity implements JavaFileStorage.FileStorag
 	}
 
 	static JavaFileStorage createStorageToTest(Context ctx, Context appContext, boolean simulateRestart) {
-		//storageToTest = new SftpStorage(ctx.getApplicationContext());
+		storageToTest = new SftpStorage(ctx.getApplicationContext());
 		//storageToTest = new PCloudFileStorage(ctx, "yCeH59Ffgtm");
 		//storageToTest = new SkyDriveFileStorage("000000004010C234", appContext);
 
 
-		storageToTest = new GoogleDriveAppDataFileStorage();
+		//storageToTest = new GoogleDriveAppDataFileStorage();
 		/*storageToTest = new WebDavStorage(new ICertificateErrorHandler() {
 			@Override
 			public boolean onValidationError(String error) {
@@ -690,6 +690,13 @@ public class MainActivity extends Activity implements JavaFileStorage.FileStorag
 		return sb.toString();
 	}
 
+	private void populateCsvMockValues(View view) {
+		EditText etSpecs = view.findViewById(R.id.mock_csv_specs);
+		etSpecs.setText("-bar,+first,-*d*");
+		EditText etCfgs = view.findViewById(R.id.mock_csv_cfg);
+		etCfgs.setText("foo,del1,bar,del2");
+	}
+
 	@Override
 	public void performManualFileSelect(boolean isForSave, final int requestCode,
 			String protocolId)
@@ -697,12 +704,13 @@ public class MainActivity extends Activity implements JavaFileStorage.FileStorag
 		if (protocolId.equals("sftp"))
 		{
 			final View view = getLayoutInflater().inflate(R.layout.sftp_credentials, null);
+			final SftpStorage sftpStorage = (SftpStorage)storageToTest;
+
+			populateCsvMockValues(view);
 
 			view.findViewById(R.id.send_public_key).setOnClickListener(v -> {
 				Intent sendIntent = new Intent();
 
-
-                SftpStorage sftpStorage = (SftpStorage)storageToTest;
                 try {
                     String pub_filename = sftpStorage.createKeyPair();
 
@@ -715,39 +723,140 @@ public class MainActivity extends Activity implements JavaFileStorage.FileStorag
                 }
                 catch (Exception ex)
                 {
-                    Toast.makeText(this,"Failed to create key pair: " + ex.getMessage(), Toast.LENGTH_LONG);
-                    return;
+                    Toast.makeText(this,"Failed to create key pair: " + ex.getMessage(), Toast.LENGTH_LONG).show();
                 }
-
-
 			});
+
+			view.findViewById(R.id.list_private_keys).setOnClickListener(v -> {
+				String[] keys = sftpStorage.getCustomKeyNames();
+				Toast.makeText(this, "keys: " + String.join(",", keys), Toast.LENGTH_LONG).show();
+			});
+
+			view.findViewById(R.id.add_private_key).setOnClickListener(v -> {
+				EditText etKeyName = view.findViewById(R.id.private_key_name);
+				String keyName = etKeyName.getText().toString();
+				EditText etKeyContent = view.findViewById(R.id.private_key_content);
+				String keyContent = etKeyContent.getText().toString();
+
+				try {
+					sftpStorage.savePrivateKeyContent(keyName, keyContent);
+					Toast.makeText(this, "Add successful", Toast.LENGTH_LONG).show();
+				}
+				catch (Exception e) {
+					Toast.makeText(this, "Add failed: " + e.getMessage(), Toast.LENGTH_LONG).show();
+				}
+			});
+
+			view.findViewById(R.id.delete_private_key).setOnClickListener(v -> {
+				EditText etKeyName = view.findViewById(R.id.private_key_name);
+				String keyName = etKeyName.getText().toString();
+
+				String exMessage = null;
+				boolean success = false;
+				try {
+					success = sftpStorage.deleteCustomKey(keyName);
+				}
+				catch (Exception e) {
+					exMessage = e.getMessage();
+				}
+				StringBuilder msg = new StringBuilder("Delete ");
+				msg.append(success ? "succeeded" : "FAILED");
+				if (exMessage != null) {
+					msg.append(" (").append(exMessage).append(")");
+				}
+				Toast.makeText(this, msg.toString(), Toast.LENGTH_LONG).show();
+			});
+
+			view.findViewById(R.id.validate_private_key).setOnClickListener(v -> {
+				EditText etKeyName = view.findViewById(R.id.private_key_name);
+				String inKeyName = etKeyName.getText().toString();
+
+				if (!inKeyName.isEmpty()) {
+					String keyResponse;
+					try {
+						keyResponse = sftpStorage.sanitizeCustomKeyName(inKeyName);
+					} catch (Exception e) {
+						keyResponse = "EX:" + e.getMessage();
+					}
+					String msg = "key: [" + inKeyName + "] -> [" + keyResponse + "]";
+					Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
+				}
+
+				EditText etKeyContent = view.findViewById(R.id.private_key_content);
+				String inKeyContent = etKeyContent.getText().toString();
+				String msg;
+				if (!inKeyContent.isEmpty()) {
+					try {
+						// We could print the key, but I don't it's that helpful
+						sftpStorage.getValidatedCustomKeyContent(inKeyContent);
+						msg = "Key content is valid";
+					} catch (Exception e) {
+						msg = "Invalid key content: " + e.getMessage();
+					}
+					Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
+				}
+			});
+
+			view.findViewById(R.id.resolve_mock_csv).setOnClickListener(v -> {
+				EditText etSpecs = view.findViewById(R.id.mock_csv_specs);
+				String specs = etSpecs.getText().toString();
+				EditText etCfg = view.findViewById(R.id.mock_csv_cfg);
+				String cfg = etCfg.getText().toString();
+				if (!specs.isBlank() && !cfg.isBlank()) {
+					String result = sftpStorage.resolveCsvValues(cfg, specs);
+					Toast.makeText(this, result, Toast.LENGTH_LONG).show();
+				}
+			});
+
+			view.findViewById(R.id.reset_mock_csv).setOnClickListener(v -> {
+				populateCsvMockValues(view);
+			});
+
 			new AlertDialog.Builder(this)
 					.setView(view)
 					.setTitle("Enter SFTP credentials")
-					.setPositiveButton("OK",new DialogInterface.OnClickListener() {
+					.setPositiveButton("OK", (dialog, which) -> {
 
-						@Override
-						public void onClick(DialogInterface dialog, int which) {
+						Toast.makeText(MainActivity.this, "Hey", Toast.LENGTH_LONG).show();
 
-							Toast.makeText(MainActivity.this, "Hey", Toast.LENGTH_LONG).show();
-
-							SftpStorage sftpStorage = (SftpStorage)storageToTest;
-							try {
-								EditText etHost = ((EditText)view.findViewById(R.id.sftp_host));
-								String host = etHost.getText().toString();
-								EditText etUser = ((EditText)view.findViewById(R.id.sftp_user));
-								String user = etUser.getText().toString();
-								EditText etPwd = ((EditText)view.findViewById(R.id.sftp_password));
-								String pwd = etPwd.getText().toString();
-								EditText etPort = ((EditText)view.findViewById(R.id.sftp_port));
-								int port = Integer.parseInt(etPort.getText().toString());
-								EditText etInitDir = ((EditText)view.findViewById(R.id.sftp_initial_dir));
-								String initialDir = etInitDir.getText().toString();
-								onReceivePathForFileSelect(requestCode, sftpStorage.buildFullPath( host, port, initialDir, user, pwd));
-							} catch (UnsupportedEncodingException e) {
-								// TODO Auto-generated catch block
-								e.printStackTrace();
+						SftpStorage sftpStorage1 = (SftpStorage)storageToTest;
+						try {
+							EditText etHost = view.findViewById(R.id.sftp_host);
+							String host = etHost.getText().toString();
+							EditText etUser = view.findViewById(R.id.sftp_user);
+							String user = etUser.getText().toString();
+							EditText etPwd = view.findViewById(R.id.sftp_password);
+							String pwd = etPwd.getText().toString();
+							EditText etPort = view.findViewById(R.id.sftp_port);
+							int port = Integer.parseInt(etPort.getText().toString());
+							EditText etInitDir = view.findViewById(R.id.sftp_initial_dir);
+							String initialDir = etInitDir.getText().toString();
+							EditText etConnectTimeout = view.findViewById(R.id.sftp_connect_timeout);
+							int connectTimeout = SftpStorage.UNSET_SFTP_CONNECT_TIMEOUT;
+							String ctStr = etConnectTimeout.getText().toString();
+							if (!ctStr.isEmpty()) {
+								try {
+									int ct = Integer.parseInt(ctStr);
+									if (connectTimeout != ct) {
+										connectTimeout = ct;
+									}
+								} catch (NumberFormatException parseEx) {
+								}
 							}
+							EditText etKeyName = view.findViewById(R.id.private_key_name);
+							String keyName = etKeyName.getText().toString();
+							EditText etKeyPassphrase = view.findViewById(R.id.private_key_passphrase);
+							String keyPassphrase = etKeyPassphrase.getText().toString();
+							EditText etKex = view.findViewById(R.id.kex);
+							String kex = etKex.getText().toString();
+							EditText etShk = view.findViewById(R.id.shk);
+							String shk = etShk.getText().toString();
+
+							onReceivePathForFileSelect(requestCode, sftpStorage1.buildFullPath(
+									host, port, initialDir, user, pwd, connectTimeout,
+									keyName, keyPassphrase, kex, shk));
+						} catch (UnsupportedEncodingException e) {
+							e.printStackTrace();
 						}
 					})
 					.create()

src/java/JavaFileStorageTest-AS/app/src/main/res/layout/sftp_credentials.xml

@@ -3,69 +3,217 @@
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
-    android:layout_margin="12dip"
-    >
-	<LinearLayout
-    android:orientation="horizontal"
-    android:layout_width="fill_parent"
-    android:layout_height="wrap_content">
-		<EditText
+    android:layout_margin="12dip">
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <EditText
             android:id="@+id/sftp_host"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
+            android:layout_weight="10"
             android:singleLine="true"
             android:inputType="textNoSuggestions"
             android:text=""
-			android:hint="@string/hint_sftp_host" />
-	  <TextView
+            android:hint="@string/hint_sftp_host" />
+        <TextView
             android:id="@+id/portsep"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text=":" />
-	<EditText
+        <EditText
             android:id="@+id/sftp_port"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
+            android:layout_weight="15"
             android:singleLine="true"
-			android:inputType="number"
-			android:text="22" 
-			android:hint="@string/hint_sftp_port" />
- </LinearLayout>
- <EditText
+            android:inputType="number"
+            android:text="22"
+            android:hint="@string/hint_sftp_port" />
+        <EditText
+            android:id="@+id/sftp_connect_timeout"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="14"
+            android:singleLine="true"
+            android:inputType="number"
+            android:text=""
+            android:hint="@string/hint_sftp_connect_timeout" />
+    </LinearLayout>
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <EditText
             android:id="@+id/sftp_user"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
+            android:layout_weight="1"
             android:singleLine="true"
             android:text=""
-			android:hint="@string/hint_username" />
-		
-	<EditText
+            android:hint="@string/hint_username" />
+        <EditText
             android:id="@+id/sftp_password"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
+            android:layout_weight="1"
             android:inputType="textPassword"
             android:singleLine="true"
             android:text=""
-			android:hint="@string/hint_pass"
-			android:importantForAccessibility="no" />
-		
-		<TextView android:id="@+id/initial_dir"
+            android:hint="@string/hint_pass"
+            android:importantForAccessibility="no" />
+    </LinearLayout>
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <TextView android:id="@+id/initial_dir"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginLeft="4dip"
             android:layout_marginTop="4dip"
             
             android:text="@string/initial_directory" />
-		<EditText
+        <EditText
             android:id="@+id/sftp_initial_dir"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
+            android:layout_marginLeft="8dip"
             android:singleLine="true"
-			android:text="/home/philipp"
-			 />
-		<Button android:id="@+id/send_public_key"
-			android:layout_width="fill_parent"
-			android:layout_height="wrap_content"
-			android:text="send public key" />
-
+            android:text="/home/philipp"
+             />
+    </LinearLayout>
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <EditText android:id="@+id/kex"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:singleLine="true"
+            android:inputType="textNoSuggestions"
+            android:text=""
+            android:hint="KEX Algs" />
+        <EditText android:id="@+id/shk"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:singleLine="true"
+            android:inputType="textNoSuggestions"
+            android:text=""
+            android:hint="Server Host Key Algs" />
+    </LinearLayout>
+    <Button android:id="@+id/send_public_key"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="send public key" />
+    <TextView
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center_horizontal"
+        android:layout_marginTop="15dp"
+        android:textStyle="bold"
+        android:text="Private Keys Functions" />
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <Button android:id="@+id/list_private_keys"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="List" />
+        <Button android:id="@+id/add_private_key"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="Add" />
+        <Button android:id="@+id/delete_private_key"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="Delete" />
+        <Button android:id="@+id/validate_private_key"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="Validate" />
+    </LinearLayout>
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+    <EditText android:id="@+id/private_key_name"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:singleLine="true"
+        android:inputType="textNoSuggestions"
+        android:text=""
+        android:hint="key name" />
+    <EditText android:id="@+id/private_key_passphrase"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:singleLine="true"
+        android:inputType="textNoSuggestions"
+        android:text=""
+        android:hint="passphrase (optional)" />
+    </LinearLayout>
+    <EditText android:id="@+id/private_key_content"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:inputType="textMultiLine"
+        android:lines="4"
+        android:text=""
+        android:hint="key content" />
+    <TextView
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center_horizontal"
+        android:layout_marginTop="15dp"
+        android:textStyle="bold"
+        android:text="CSV Resolver Functions" />
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <EditText android:id="@+id/mock_csv_specs"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:singleLine="true"
+            android:inputType="textNoSuggestions"
+            android:text=""
+            android:hint="Test specs" />
+        <EditText android:id="@+id/mock_csv_cfg"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:singleLine="true"
+            android:inputType="textNoSuggestions"
+            android:text=""
+            android:hint="Test config" />
+    </LinearLayout>
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+        <Button android:id="@+id/reset_mock_csv"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:layout_marginLeft="50dp"
+            android:layout_marginRight="5dp"
+            android:text="Reset" />
+        <Button android:id="@+id/resolve_mock_csv"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:layout_marginRight="50dp"
+            android:layout_marginLeft="5dp"
+            android:text="Resolve" />
+    </LinearLayout>
 </LinearLayout>

src/java/JavaFileStorageTest-AS/app/src/main/res/values/strings.xml

@@ -333,6 +333,7 @@
 
 	<string name="hint_sftp_host">host</string>
 	<string name="hint_sftp_port">port</string>
+    <string name="hint_sftp_connect_timeout">timeout sec</string>
 
 	<string name="select_storage_type">Select the storage type:</string>
 
@@ -524,6 +525,6 @@ Initial public release
 		<item>Do not accept invalid certificates</item>
 	</string-array>
 	
-	<string name="initial_directory">Initial directory (optional):</string>
+	<string name="initial_directory">Initial dir (optional):</string>
     
 </resources>

src/java/android-filechooser-AS/app/src/main/java/group/pals/android/lib/ui/filechooser/FileChooserActivity.java

@@ -221,7 +221,6 @@ public class FileChooserActivity extends FragmentActivity {
     
     public static final String EXTRA_RESULT_FILE_EXISTS = CLASSNAME + ".result_file_exists";
     
-    
 
     /*
      * CONTROLS

src/java/android-filechooser-AS/app/src/main/java/group/pals/android/lib/ui/filechooser/FragmentFiles.java

@@ -269,7 +269,6 @@ public class FragmentFiles extends Fragment implements
                 FileChooserActivity.EXTRA_MAX_FILE_COUNT, 1000);
         mFileAdapter = new BaseFileAdapter(getActivity(), mFilterMode,
                 mIsMultiSelection);
-        
 
         /*
          * History.
@@ -2268,12 +2267,15 @@ public class FragmentFiles extends Fragment implements
             }
 
             if (mIsSaveDialog) {
-                mTextSaveas.setText(BaseFileProviderUtils.getFileName(cursor));
+                String fileName = BaseFileProviderUtils.getFileName(cursor);
+                Uri uri = BaseFileProviderUtils.getUri(cursor);
+
+                mTextSaveas.setText(fileName);
                 /*
                  * Always set tag after setting text, or tag will be reset to
                  * null.
                  */
-                mTextSaveas.setTag(BaseFileProviderUtils.getUri(cursor));
+                mTextSaveas.setTag(uri);
             }
 
             if (mDoubleTapToChooseFiles) {
@@ -2286,10 +2288,12 @@ public class FragmentFiles extends Fragment implements
                 if (mIsMultiSelection)
                     return;
 
-                if (mIsSaveDialog)
+                if (mIsSaveDialog) {
                     checkSaveasFilenameAndFinish();
-                else
+                }
+                else {
                     finish(BaseFileProviderUtils.getUri(cursor));
+                }
             }// single tap to choose files
         }// onItemClick()
     };// mViewFilesOnItemClickListener

src/java/android-filechooser-AS/app/src/main/java/keepass2android/kp2afilechooser/FileEntry.java

@@ -15,4 +15,24 @@ public class FileEntry {
 		isDirectory = false;
 		canRead = canWrite = true;
 	}
+
+	@Override
+	public String toString() {
+		StringBuilder s = new StringBuilder("kp2afilechooser.FileEntry{")
+				.append(displayName).append("|")
+				.append("path=").append(path).append(",sz=").append(sizeInBytes)
+				.append(",").append(isDirectory ? "dir" : "file")
+				.append(",lastMod=").append(lastModifiedTime);
+
+		StringBuilder perms = new StringBuilder();
+		if (canRead)
+			perms.append("r");
+		if (canWrite)
+			perms.append("w");
+		if (perms.length() > 0) {
+			s.append(",").append(perms);
+		}
+
+		return s.append("}").toString();
+	}
 }

src/java/android-filechooser-AS/app/src/main/java/keepass2android/kp2afilechooser/Kp2aFileChooserBridge.java

@@ -20,6 +20,7 @@ public class Kp2aFileChooserBridge {
 		.buildUpon()
 		.appendPath(defaultPath)
 		.build());
+
 		return intent;
 	}
 }

src/java/android-filechooser-AS/app/src/main/java/keepass2android/kp2afilechooser/Kp2aFileProvider.java

@@ -306,10 +306,9 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
 	            String parentPath = getParentPath(path);
 	            
         		
-        		if (parentPath == null)
-	            {
+        		if (parentPath == null) {
         			if (Utils.doLog())
-        				Log.d(CLASSNAME, "parent file is null");
+                        Log.d(CLASSNAME, "parent file is null");
 	                return null;
 	            }
                 FileEntry e;
@@ -501,10 +500,10 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
 		RowBuilder newRow = matrixCursor.newRow();
 		newRow.add(id);// _ID
 		newRow.add(BaseFile
-		        .genContentIdUriBase(
-		                getAuthority())
-		        .buildUpon().appendPath(f.path)
-		        .build().toString());
+                .genContentIdUriBase(
+                        getAuthority())
+                .buildUpon().appendPath(f.path)
+                .build().toString());
 		newRow.add(f.path);
 		if (f.displayName == null)
 			Log.w("KP2AJ", "displayName is null for " + f.path);
@@ -549,7 +548,7 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
     //puts the file entry in the cache for later reuse with retrieveFileInfo
 	private void updateFileEntryCache(FileEntry f) {
 		if (f != null)
-			fileEntryMap.put(f.path, f);
+            fileEntryMap.put(f.path, f);
 	}
 	//removes the file entry from the cache (if cached). Should be called whenever the file changes
 	private void removeFromCache(String filename, boolean recursive) {
@@ -584,7 +583,7 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
 
 	//returns the file entry from the cache if present or queries the concrete provider method to return the file info
     private FileEntry getFileEntryCached(String filename) {
-    	//check if enry is cached:
+    	//check if entry is cached:
     	FileEntry cachedEntry = fileEntryMap.get(filename);
     	if (cachedEntry != null)
     	{
@@ -728,7 +727,7 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
         if (targetParent != null && targetParent.startsWith(source))
         {
         	if (Utils.doLog())
-        		Log.d("KP2A_FC_P", source+" is parent of "+target);
+                Log.d("KP2A_FC_P", source + " is parent of " + target);
             return BaseFileProviderUtils.newClosedCursor();
         }
         if (Utils.doLog())
@@ -768,28 +767,37 @@ public abstract class Kp2aFileProvider extends BaseFileProvider {
 
     private String getParentPath(String path)
     {
-    	path = removeTrailingSlash(path);
-    	if (path.indexOf("://") == -1)
-    	{
-    		Log.d("KP2A_FC_P", "invalid path: " + path);
-    		return null; 
-    	}
-    	String pathWithoutProtocol = path.substring(path.indexOf("://")+3);
-    	int lastSlashPos = path.lastIndexOf("/");
-    	if (pathWithoutProtocol.indexOf("/") == -1)
-    	{
-    		Log.d("KP2A_FC_P", "parent of " + path +" is null");
-    		return null;
-    	}
-    	else
-    	{
-    		String parent = path.substring(0, lastSlashPos)+"/";
-    		Log.d("KP2A_FC_P", "parent of " + path +" is "+parent);
-    		return parent;
-    	}
+        String params = null;
+        int paramsIdx = path.lastIndexOf("?");
+        if (paramsIdx > 0) {
+            params = path.substring(paramsIdx);
+            path = path.substring(0, paramsIdx);
+        }
+
+        path = removeTrailingSlash(path);
+        if (path.indexOf("://") == -1)
+        {
+            Log.d("KP2A_FC_P", "invalid path: " + path);
+            return null;
+        }
+        String pathWithoutProtocol = path.substring(path.indexOf("://") + 3);
+        int lastSlashPos = path.lastIndexOf("/");
+        if (pathWithoutProtocol.indexOf("/") == -1)
+        {
+            Log.d("KP2A_FC_P", "parent of " + path + " is null");
+            return null;
+        }
+        else
+        {
+            String parent = path.substring(0, lastSlashPos) + "/";
+            if (params != null) {
+                parent += params;
+            }
+            Log.d("KP2A_FC_P", "parent of " + path +" is " + parent);
+            return parent;
+        }
     }
     
-    
 
 	protected abstract FileEntry getFileEntry(String path, StringBuilder errorMessageBuilder) throws Exception;
     

src/keepass2android/FileSelectHelper.cs

@@ -42,6 +42,12 @@ namespace keepass2android
 	    private readonly string _schemeSeparator = "://";
 	    private bool _tryGetPermanentAccess;
 
+		private const int SftpModeSpinnerPasswd = 0;
+		private const int SftpModeSpinnerPubKey = 1;
+		private const int SftpModeSpinnerCustomKey = 2;
+
+		private const int SftpKeySpinnerCreateNewIdx = 0;
+
 	    public string DefaultExtension { get; set; }
 
 		public FileSelectHelper(Activity activity, bool isForSave, bool tryGetPermanentAccess, int requestCode)
@@ -57,71 +63,210 @@ namespace keepass2android
 #if !EXCLUDE_JAVAFILESTORAGE && !NoNet
 			AlertDialog.Builder builder = new AlertDialog.Builder(activity);
 			View dlgContents = activity.LayoutInflater.Inflate(Resource.Layout.sftpcredentials, null);
+			var ctx = activity.ApplicationContext;
+            var fileStorage = new Keepass2android.Javafilestorage.SftpStorage(ctx);
 
-		    var spinner = dlgContents.FindViewById<Spinner>(Resource.Id.sftp_auth_mode_spinner);
-		    dlgContents.FindViewById<Button>(Resource.Id.send_public_key_button).Click += (sender, args) =>
-		    {
-		        var fileStorage = new Keepass2android.Javafilestorage.SftpStorage(activity.ApplicationContext);
-		        string pub_filename = fileStorage.CreateKeyPair();
+            LinearLayout addNewBtn = dlgContents.FindViewById<LinearLayout>(Resource.Id.sftp_add_key_group);
+            Button deleteBtn = dlgContents.FindViewById<Button>(Resource.Id.sftp_delete_key_button);
+            EditText keyNameTxt = dlgContents.FindViewById<EditText>(Resource.Id.sftp_key_name);
+            EditText keyContentTxt = dlgContents.FindViewById<EditText>(Resource.Id.sftp_key_content);
 
-		        Intent sendIntent = new Intent();
-                sendIntent.SetAction(Intent.ActionSend);
-		        sendIntent.PutExtra(Intent.ExtraText, System.IO.File.ReadAllText(pub_filename));
+            var keySpinner = dlgContents.FindViewById<Spinner>(Resource.Id.sftp_key_names);
+			var keyNamesAdapter = new ArrayAdapter(ctx, Android.Resource.Layout.SimpleSpinnerDropDownItem, new List<string>());
+			UpdatePrivateKeyNames(keyNamesAdapter, fileStorage, ctx);
+			keyNamesAdapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
+			keySpinner.Adapter = keyNamesAdapter;
+			keySpinner.SetSelection(SftpKeySpinnerCreateNewIdx);
 
-		        sendIntent.PutExtra(Intent.ExtraSubject, "Keepass2Android sftp public key");
-		        sendIntent.SetType("text/plain");
-		        activity.StartActivity(Intent.CreateChooser(sendIntent, "Send public key to..."));
-            };
+			keySpinner.ItemSelected += (sender, args) =>
+			{
+                if (keySpinner.SelectedItemPosition == SftpKeySpinnerCreateNewIdx)
+				{
+					keyNameTxt.Text = "";
+					keyContentTxt.Text = "";
+					addNewBtn.Visibility = ViewStates.Visible;
+					deleteBtn.Visibility = ViewStates.Gone;
+				}
+				else
+				{
+					addNewBtn.Visibility = ViewStates.Gone;
+					deleteBtn.Visibility = ViewStates.Visible;
+				}
+			};
 
+            var authModeSpinner = dlgContents.FindViewById<Spinner>(Resource.Id.sftp_auth_mode_spinner);
+			dlgContents.FindViewById<Button>(Resource.Id.send_public_key_button).Click += (sender, args) =>
+			{
+                string pub_filename = fileStorage.CreateKeyPair();
 
-            spinner.ItemSelected += (sender, args) =>
-		    {
-		        if (spinner.SelectedItemPosition == 0)
-		        {
-		            dlgContents.FindViewById<EditText>(Resource.Id.sftp_password).Visibility = ViewStates.Visible;
-		            dlgContents.FindViewById<Button>(Resource.Id.send_public_key_button).Visibility = ViewStates.Gone;
-                }
-		        else
-		        {
-		            dlgContents.FindViewById<EditText>(Resource.Id.sftp_password).Visibility = ViewStates.Gone;
-		            dlgContents.FindViewById<Button>(Resource.Id.send_public_key_button).Visibility = ViewStates.Visible;
+				Intent sendIntent = new Intent();
+				sendIntent.SetAction(Intent.ActionSend);
+				sendIntent.PutExtra(Intent.ExtraText, System.IO.File.ReadAllText(pub_filename));
+
+				sendIntent.PutExtra(Intent.ExtraSubject, "Keepass2Android sftp public key");
+				sendIntent.SetType("text/plain");
+				activity.StartActivity(Intent.CreateChooser(sendIntent, "Send public key to..."));
+			};
+
+			dlgContents.FindViewById<Button>(Resource.Id.sftp_save_key_button).Click += (sender, args) =>
+			{
+				string keyName = keyNameTxt.Text;
+				string keyContent = keyContentTxt.Text;
+
+				string toastMsg = null;
+                if (!string.IsNullOrEmpty(keyName) && !string.IsNullOrEmpty(keyContent))
+				{
+					try
+					{
+						fileStorage.SavePrivateKeyContent(keyName, keyContent);
+                        keyNameTxt.Text = "";
+						keyContentTxt.Text = "";
+                        toastMsg = ctx.GetString(Resource.String.private_key_saved);
+                    }
+					catch (Exception e)
+					{
+						toastMsg = ctx.GetString(Resource.String.private_key_save_failed,
+							new Java.Lang.Object[] { e.Message });
+					}
+				}
+				else
+				{
+					toastMsg = ctx.GetString(Resource.String.private_key_info);
+				}
+
+				if (toastMsg!= null) {
+                    Toast.MakeText(_activity, toastMsg, ToastLength.Long).Show();
                 }
+
+				UpdatePrivateKeyNames(keyNamesAdapter, fileStorage, ctx);
+				keySpinner.SetSelection(ResolveKeySpinnerSelection(keyNamesAdapter, keyName));
+			};
+
+			dlgContents.FindViewById<Button>(Resource.Id.sftp_delete_key_button).Click += (sender, args) =>
+			{
+				int selectedKey = dlgContents.FindViewById<Spinner>(Resource.Id.sftp_key_names).SelectedItemPosition;
+				string keyName = ResolveSelectedKeyName(keyNamesAdapter, selectedKey);
+				if (!string.IsNullOrEmpty(keyName))
+				{
+					bool deleted = fileStorage.DeleteCustomKey(keyName);
+
+					int msgId = deleted ? Resource.String.private_key_delete : Resource.String.private_key_delete_failed;
+					string msg = ctx.GetString(msgId, new Java.Lang.Object[] { keyName });
+                    Toast.MakeText(_activity, msg, ToastLength.Long).Show();
+
+					UpdatePrivateKeyNames(keyNamesAdapter, fileStorage, ctx);
+					keySpinner.SetSelection(SftpKeySpinnerCreateNewIdx);
+				}
+			};
+
+			authModeSpinner.ItemSelected += (sender, args) =>
+		    {
+				var passwordBox = dlgContents.FindViewById<EditText>(Resource.Id.sftp_password);
+				var publicKeyButton = dlgContents.FindViewById<Button>(Resource.Id.send_public_key_button);
+				var keyfileGroup = dlgContents.FindViewById<LinearLayout>(Resource.Id.sftp_keyfile_group);
+
+                switch (authModeSpinner.SelectedItemPosition)
+			    {
+				    case SftpModeSpinnerPasswd:
+					    passwordBox.Visibility = ViewStates.Visible;
+					    publicKeyButton.Visibility = ViewStates.Gone;
+					    keyfileGroup.Visibility = ViewStates.Gone;
+					    break;
+				    case SftpModeSpinnerPubKey:
+					    passwordBox.Visibility = ViewStates.Gone;
+					    publicKeyButton.Visibility = ViewStates.Visible;
+					    keyfileGroup.Visibility = ViewStates.Gone;
+					    break;
+				    case SftpModeSpinnerCustomKey:
+					    passwordBox.Visibility = ViewStates.Gone;
+					    publicKeyButton.Visibility = ViewStates.Gone;
+					    keyfileGroup.Visibility = ViewStates.Visible;
+					    break;
+			    }
 		    };
 
             if (!defaultPath.EndsWith(_schemeSeparator))
 		    {
-		        var fileStorage = new Keepass2android.Javafilestorage.SftpStorage(activity.ApplicationContext);
                 SftpStorage.ConnectionInfo ci = fileStorage.SplitStringToConnectionInfo(defaultPath);
 		        dlgContents.FindViewById<EditText>(Resource.Id.sftp_host).Text = ci.Host;
 		        dlgContents.FindViewById<EditText>(Resource.Id.sftp_port).Text = ci.Port.ToString();
 		        dlgContents.FindViewById<EditText>(Resource.Id.sftp_user).Text = ci.Username;
 		        dlgContents.FindViewById<EditText>(Resource.Id.sftp_password).Text = ci.Password;
+				dlgContents.FindViewById<EditText>(Resource.Id.sftp_key_name).Text = ci.KeyName;
+				dlgContents.FindViewById<EditText>(Resource.Id.sftp_key_passphrase).Text = ci.KeyPassphrase;
 		        dlgContents.FindViewById<EditText>(Resource.Id.sftp_initial_dir).Text = ci.LocalPath;
-		        if (string.IsNullOrEmpty(ci.Password))
+		        if (ci.ConnectTimeoutSec != SftpStorage.UnsetSftpConnectTimeout)
 		        {
-		            spinner.SetSelection(1);
+			        dlgContents.FindViewById<EditText>(Resource.Id.sftp_connect_timeout).Text = ci.ConnectTimeoutSec.ToString();
 		        }
+				
+				if (ci.ConfigOpts.Contains(SftpStorage.SshCfgKex))
+				{
+					dlgContents.FindViewById<EditText>(Resource.Id.sftp_kex).Text = ci.ConfigOpts[SftpStorage.SshCfgKex].ToString();
+				}
+                if (ci.ConfigOpts.Contains(SftpStorage.SshCfgServerHostKey))
+                {
+                    dlgContents.FindViewById<EditText>(Resource.Id.sftp_shk).Text = ci.ConfigOpts[SftpStorage.SshCfgServerHostKey].ToString();
+                }
+
+                if (!string.IsNullOrEmpty(ci.Password))
+				{
+					authModeSpinner.SetSelection(SftpModeSpinnerPasswd);
+				} else if (!string.IsNullOrEmpty(ci.KeyName))
+				{
+					authModeSpinner.SetSelection(SftpModeSpinnerCustomKey);
+					keySpinner.SetSelection(ResolveKeySpinnerSelection(keyNamesAdapter, ci.KeyName));
+				} else
+				{
+					authModeSpinner.SetSelection(SftpModeSpinnerPubKey);
+				}
+
             }
 
 			builder.SetView(dlgContents);
-			builder.SetPositiveButton(Android.Resource.String.Ok,
-									  (sender, args) =>
-									  {
-										  string host = dlgContents.FindViewById<EditText>(Resource.Id.sftp_host).Text;
-										  string portText = dlgContents.FindViewById<EditText>(Resource.Id.sftp_port).Text;
-										  int port = Keepass2android.Javafilestorage.SftpStorage.DefaultSftpPort;
-										  if (!string.IsNullOrEmpty(portText))
-											  int.TryParse(portText, out port);
-										  string user = dlgContents.FindViewById<EditText>(Resource.Id.sftp_user).Text;
-										  string password = dlgContents.FindViewById<EditText>(Resource.Id.sftp_password).Text;
-										  string initialPath = dlgContents.FindViewById<EditText>(Resource.Id.sftp_initial_dir).Text;
-									      if (string.IsNullOrEmpty(initialPath))
-									          initialPath = "/";
-                                          string sftpPath = new Keepass2android.Javafilestorage.SftpStorage(activity.ApplicationContext).BuildFullPath(host, port, initialPath, user,
-																										  password);
-										  onStartBrowse(sftpPath);
-									  });
-			EventHandler<DialogClickEventArgs> evtH = new EventHandler<DialogClickEventArgs>((sender, e) => onCancel());
+            builder.SetPositiveButton(Android.Resource.String.Ok, (sender, args) => {
+				int idx = 0;
+                string host = dlgContents.FindViewById<EditText>(Resource.Id.sftp_host).Text;
+                string portText = dlgContents.FindViewById<EditText>(Resource.Id.sftp_port).Text;
+                int port = SftpStorage.DefaultSftpPort;
+                if (!string.IsNullOrEmpty(portText))
+                    int.TryParse(portText, out port);
+                string user = dlgContents.FindViewById<EditText>(Resource.Id.sftp_user).Text;
+
+                string password = null;
+                string keyName = null, keyPassphrase = null;
+                switch (dlgContents.FindViewById<Spinner>(Resource.Id.sftp_auth_mode_spinner).SelectedItemPosition)
+                {
+                    case SftpModeSpinnerPasswd:
+                        password = dlgContents.FindViewById<EditText>(Resource.Id.sftp_password).Text;
+                        break;
+                    case SftpModeSpinnerPubKey:
+                        break;
+                    case SftpModeSpinnerCustomKey:
+						keyName = ResolveSelectedKeyName(keyNamesAdapter, keySpinner.SelectedItemPosition);
+						keyPassphrase = dlgContents.FindViewById<EditText>(Resource.Id.sftp_key_passphrase).Text;
+                        break;
+                }
+
+                string initialPath = dlgContents.FindViewById<EditText>(Resource.Id.sftp_initial_dir).Text;
+                if (string.IsNullOrEmpty(initialPath))
+                    initialPath = "/";
+                string connectTimeoutText = dlgContents.FindViewById<EditText>(Resource.Id.sftp_connect_timeout).Text;
+                int connectTimeout = SftpStorage.UnsetSftpConnectTimeout;
+                if (!string.IsNullOrEmpty(connectTimeoutText))
+                {
+                    int.TryParse(connectTimeoutText, out connectTimeout);
+                }
+				string kexAlgorithms = dlgContents.FindViewById<EditText>(Resource.Id.sftp_kex).Text;
+				string shkAlgorithms = dlgContents.FindViewById<EditText>(Resource.Id.sftp_shk).Text;
+
+                string sftpPath = fileStorage.BuildFullPath(
+                    host, port, initialPath, user, password, connectTimeout, keyName, keyPassphrase,
+					kexAlgorithms, shkAlgorithms);
+
+                onStartBrowse(sftpPath);
+            });
+            EventHandler<DialogClickEventArgs> evtH = new EventHandler<DialogClickEventArgs>((sender, e) => onCancel());
 
 			builder.SetNegativeButton(Android.Resource.String.Cancel, evtH);
 			builder.SetTitle(activity.GetString(Resource.String.enter_sftp_login_title));
@@ -129,9 +274,41 @@ namespace keepass2android
 
 			dialog.Show();
 #endif
-		}
+        }
 
-		private void ShowHttpDialog(Activity activity, Util.FileSelectedHandler onStartBrowse, Action onCancel, string defaultPath)
+#if !EXCLUDE_JAVAFILESTORAGE && !NoNet
+        private void UpdatePrivateKeyNames(ArrayAdapter dataView, SftpStorage storage, Context ctx)
+        {
+			dataView.Clear();
+			dataView.Add(ctx.GetString(Resource.String.private_key_create_new));
+			foreach (string keyName in storage.GetCustomKeyNames()) 
+				dataView.Add(keyName);
+        }
+
+        private int ResolveKeySpinnerSelection(ArrayAdapter dataView, string keyName)
+        {
+			int idx = -1;
+			for (int i = 0; i < dataView.Count; i++)
+			{
+				string itemName = dataView.GetItem(i).ToString();
+				if (string.Equals(keyName, itemName)) {
+					idx = i;
+					break;
+				}
+			}
+			return idx < 0 ? SftpKeySpinnerCreateNewIdx : idx;
+        }
+
+        private string ResolveSelectedKeyName(ArrayAdapter dataView, int selectedItem)
+        {
+            if (selectedItem != SftpKeySpinnerCreateNewIdx && selectedItem > 0 && selectedItem < dataView.Count)
+                return dataView.GetItem(selectedItem).ToString();
+            else
+                return null;
+        }
+#endif
+
+        private void ShowHttpDialog(Activity activity, Util.FileSelectedHandler onStartBrowse, Action onCancel, string defaultPath)
 		{
 #if !EXCLUDE_JAVAFILESTORAGE && !NoNet
 			AlertDialog.Builder builder = new AlertDialog.Builder(activity);

src/keepass2android/Resources/layout/sftpcredentials.xml

@@ -61,17 +61,80 @@
   </LinearLayout>
 		
 	<EditText
-            android:id="@+id/sftp_password"
+        android:id="@+id/sftp_password"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:inputType="textPassword"
+        android:singleLine="true"
+        android:hint="@string/hint_pass"
+	    android:importantForAccessibility="no"/>
+
+    <Button
+        android:id="@+id/send_public_key_button"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/send_public_key" />
+
+    <LinearLayout
+        android:id="@+id/sftp_keyfile_group"
+        android:orientation="vertical"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content">
+	
+        <LinearLayout
+            android:orientation="horizontal"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content">
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/private_key_select" />
+            <Spinner
+                android:id="@+id/sftp_key_names"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginLeft="3dp" />
+        </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/sftp_add_key_group"
+            android:orientation="vertical"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content">
+            <EditText android:id="@+id/sftp_key_name"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:hint="@string/hint_sftp_key_name" />
+		    <EditText
+                android:id="@+id/sftp_key_content"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+		        android:inputType="textMultiLine"
+                android:minLines="1"
+                android:maxLines="6"
+			    android:hint="@string/hint_sftp_key_content" />
+            <Button
+                android:id="@+id/sftp_save_key_button"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:text="@string/save_key" />
+         </LinearLayout>
+         <Button
+                android:id="@+id/sftp_delete_key_button"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:text="@string/delete_key" />
+        <EditText
+            android:id="@+id/sftp_key_passphrase"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
-            android:inputType="textPassword"
             android:singleLine="true"
-            android:hint="@string/hint_pass"
-	          android:importantForAccessibility="no"/>
-  <Button  android:id="@+id/send_public_key_button"
-           android:layout_width="fill_parent"
-           android:layout_height="wrap_content"
-           android:text="@string/send_public_key" />
+		    android:inputType="textPassword"
+			android:hint="@string/hint_sftp_key_passphrase" />
+
+    </LinearLayout>
   
 		
 		<TextView android:id="@+id/initial_dir"
@@ -88,6 +151,49 @@
             android:singleLine="true"
 			android:text="/"
 			 />
-		
 
-</LinearLayout>
+		<TextView android:id="@+id/connect_timeout"
+		    android:layout_width="wrap_content"
+		    android:layout_height="wrap_content"
+		    android:layout_marginLeft="4dip"
+		    android:layout_marginTop="4dip"
+		    android:text="@string/connect_timeout" />
+	    <EditText
+			android:id="@+id/sftp_connect_timeout"
+			android:layout_width="fill_parent"
+			android:layout_height="wrap_content"
+			android:singleLine="true"
+			android:inputType="number" />
+
+    	<TextView android:id="@+id/sftp_kex_title"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginLeft="4dip"
+            android:layout_marginTop="4dip"
+            android:text="@string/sftp_kex_title" />
+		<EditText
+            android:id="@+id/sftp_kex"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+		    android:inputType="textNoSuggestions"
+            android:hint="@string/hint_sftp_kex"
+            android:singleLine="true"
+			android:text=""
+			 />
+        <TextView android:id="@+id/sftp_shk_title"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginLeft="4dip"
+            android:layout_marginTop="4dip"
+            android:text="@string/sftp_shk_title" />
+		<EditText
+            android:id="@+id/sftp_shk"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+		    android:inputType="textNoSuggestions"
+            android:hint="@string/hint_sftp_shk"
+            android:singleLine="true"
+			android:text=""
+			 />
+
+</LinearLayout>

src/keepass2android/Resources/values/config.xml

@@ -98,6 +98,7 @@
 	<string name="TrayTotp_SeedField_key">TrayTotp_SeedField_key</string>
 	<string name="TrayTotp_prefs_key">TrayTotp_prefs_key</string>
   <string name="DebugLog_key">DebugLog_key</string>
+  <string name="JSchDebug_key">JSchDebug_key</string>
   <string name="DebugLog_prefs_key">DebugLog_prefs_key</string>
   <string name="DebugLog_send_key">DebugLog_send</string>
   <string name="AutofillDisabledQueriesPreference_key">AutofillDisabledQueriesPreference_key</string>

src/keepass2android/Resources/values/strings.xml

@@ -167,6 +167,7 @@
   <string name="hint_keyfile">key file</string>
   <string name="hint_length">length</string>
   <string name="hint_pass">password</string>
+  <string name="hint_keyfile_path">SSH private key path</string>
   <string name="hint_login_pass">Password</string>
   <string name="hint_title">name</string>
   <string name="hint_url">URL</string>
@@ -589,9 +590,27 @@
   <string name="hint_sftp_host">host (ex: 192.168.0.1)</string>
 	<string name="hint_sftp_port">port</string>
 	<string name="initial_directory">Initial directory (optional):</string>
+    <string name="connect_timeout">Connection timeout seconds (optional):"</string>
 	<string name="enter_sftp_login_title">Enter SFTP login data:</string>
   <string name="sftp_auth_mode">Authentication mode</string>
   <string name="send_public_key">Send public key...</string>
+  <string name="select_private_keyfile">Select private key...</string>
+	<string name="hint_sftp_key_name">New key name</string>
+	<string name="hint_sftp_key_content">New key content</string>
+	<string name="private_key_saved">Private key saved</string>
+	<string name="private_key_save_failed">FAILED to save private key: %1$s</string>
+	<string name="private_key_info">Enter key name and content to save</string>
+	<string name="private_key_delete">Deleted private key: %1$s</string>
+	<string name="private_key_delete_failed">FAILED to deleted private key: %1$s</string>
+	<string name="save_key">Save Private Key</string>
+	<string name="delete_key">Delete Private Key</string>
+	<string name="private_key_select">Selected private key</string>
+	<string name="private_key_create_new">[Add New...]</string>
+	<string name="hint_sftp_key_passphrase">Key passphrase (optional)</string>
+	<string name="sftp_kex_title">Key Exchange (KEX) Algorithm(s) (optional)</string>
+	<string name="hint_sftp_kex">"Comma-separated names/spec</string>
+	<string name="sftp_shk_title">Server Host Key Algorithm(s) (optional)</string>
+	<string name="hint_sftp_shk">"Comma-separated names/spec</string>
 
   <string name="enter_ftp_login_title">Enter FTP login data:</string>
 
@@ -680,6 +699,7 @@
 	<string name="TrayTotp_prefs">TrayTotp</string>
   <string name="DebugLog_prefs_prefs">Log-File for Debugging</string>
   <string name="DebugLog_title">Use log file</string>
+  <string name="JSchDebug_title">SFTP debug logging</string>
   <string name="DebugLog_summary">Write app output to a local log file</string>
   <string name="DebugLog_send">Send debug log...</string>
   
@@ -1325,7 +1345,8 @@ Initial public release
 	</string-array>
   <string-array name="sftp_auth_modes">
     <item>Password</item>
-    <item>Private/Public key</item>
+    <item>K2A Private/Public key</item>
+    <item>Custom Private key</item>
   </string-array>
 	<string-array name="AcceptAllServerCertificates_options">
 		<item>Ignore certificate validation failures</item>

src/keepass2android/Resources/xml/preferences.xml

@@ -670,10 +670,17 @@
 							  android:defaultValue="false"
 							  android:title="@string/DebugLog_title"
 							  android:key="@string/DebugLog_key" />
+
       <Preference
                android:enabled="true"
                android:title="@string/DebugLog_send"
                android:key="@string/DebugLog_send_key" />
+      <CheckBoxPreference
+							android:enabled="true"
+							  android:persistent="false"
+							  android:defaultValue="false"
+							  android:title="@string/JSchDebug_title"
+							  android:key="@string/JSchDebug_key" />
     </PreferenceScreen>
     </PreferenceScreen>
 

src/keepass2android/settings/DatabaseSettingsActivity.cs

@@ -178,6 +178,12 @@ namespace keepass2android
             FindPreference(GetString(Resource.String.DebugLog_key)).PreferenceChange += OnDebugLogChanged;
             FindPreference(GetString(Resource.String.DebugLog_send_key)).PreferenceClick += OnSendDebug;
 
+#if !EXCLUDE_JAVAFILESTORAGE && !NoNet
+            FindPreference(GetString(Resource.String.JSchDebug_key)).PreferenceChange += OnJSchDebugChanged;
+#else
+            FindPreference(GetString(Resource.String.JSchDebug_key)).Enabled = false;
+#endif
+
             HashSet<string> supportedLocales = new HashSet<string>() { "en", "af", "ar", "az", "be", "bg", "ca", "cs", "da", "de", "el", "es", "eu", "fa", "fi", "fr", "gl", "he", "hr", "hu", "id", "in", "it", "iw", "ja", "ko", "ml", "nb", "nl", "nn", "no", "pl", "pt", "ro", "ru", "si", "sk", "sl", "sr", "sv", "tr", "uk", "vi", "zh" };
             var languagePref = (ListPreference)FindPreference(GetString(Resource.String.app_language_pref_key));
             new AppLanguageManager(this, languagePref, supportedLocales);
@@ -381,18 +387,37 @@ namespace keepass2android
 
 	    private void OnDebugLogChanged(object sender, Preference.PreferenceChangeEventArgs e)
 	    {
-		    if ((bool)e.NewValue)
-		    {
-			    Kp2aLog.CreateLogFile();
-		    }
+            if ((bool)e.NewValue)
+                Kp2aLog.CreateLogFile();
 		    else
-		    {
-			    Kp2aLog.FinishLogFile();
-		    }
+                Kp2aLog.FinishLogFile();
 
-	    }
+#if !EXCLUDE_JAVAFILESTORAGE && !NoNet
+            bool jschLogEnable = PreferenceManager.GetDefaultSharedPreferences(Application.Context)
+                .GetBoolean(Application.Context.GetString(Resource.String.JSchDebug_key), false);
+            SetJSchLogging(jschLogEnable);
+#endif
+        }
 
-	    private void AlgorithmPrefChange(object sender, Preference.PreferenceChangeEventArgs preferenceChangeEventArgs)
+#if !EXCLUDE_JAVAFILESTORAGE && !NoNet
+        private void OnJSchDebugChanged(object sender, Preference.PreferenceChangeEventArgs e)
+        {
+            SetJSchLogging((bool)e.NewValue);
+        }
+
+        private void SetJSchLogging(bool enabled)
+        {
+            var sftpStorage = new Keepass2android.Javafilestorage.SftpStorage(Context);
+            string? logFilename = null;
+            if (Kp2aLog.LogToFile)
+            {
+                logFilename = Kp2aLog.LogFilename;
+            }
+            sftpStorage.SetJschLogging(enabled, logFilename);
+        }
+#endif
+
+        private void AlgorithmPrefChange(object sender, Preference.PreferenceChangeEventArgs preferenceChangeEventArgs)
 	    {
 			var db = App.Kp2a.CurrentDb;
 			var previousCipher = db.KpDatabase.DataCipherUuid;
@@ -835,7 +860,7 @@ namespace keepass2android
 
 #if DEBUG
             preference.Enabled = (usageCount > 1);
-#else 
+#else
 			preference.Enabled = (usageCount > 50);
 #endif
             preference.PreferenceChange += delegate(object sender, Preference.PreferenceChangeEventArgs args)