支持低于android7的设备和支持sftp协议

app/build.gradle

@@ -17,10 +17,10 @@ android {
     buildToolsVersion '28.0.3'
     defaultConfig {
         applicationId "com.virjar.sshdroid"
-        minSdkVersion 27
+        minSdkVersion 24
         targetSdkVersion 27
-        versionCode 1
-        versionName "1.0"
+        versionCode 3
+        versionName "1.3"
 
 
         signingConfig signingConfigs.config
@@ -48,7 +48,9 @@ dependencies {
     implementation "com.android.support:support-v4:27.1.1"
     implementation "com.android.support:support-annotations:28.0.0"
     implementation 'org.slf4j:slf4j-api:1.7.31'
+    implementation('org.apache.sshd:sshd-core:2.7.0')
     implementation('org.apache.sshd:sshd-scp:2.7.0')
+    implementation('org.apache.sshd:sshd-sftp:2.7.0')
     implementation 'org.bouncycastle:bcpkix-jdk15on:1.69'
 
 

app/src/main/java/com/virjar/sshdroid/SSHD.java

@@ -14,6 +14,7 @@ import org.apache.sshd.server.auth.password.AcceptAllPasswordAuthenticator;
 import org.apache.sshd.server.auth.pubkey.AcceptAllPublickeyAuthenticator;
 import org.apache.sshd.server.forward.AcceptAllForwardingFilter;
 import org.apache.sshd.server.shell.ProcessShellFactory;
+import org.apache.sshd.sftp.server.SftpSubsystemFactory;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 
 import java.io.BufferedReader;
@@ -22,6 +23,7 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.security.Security;
+import java.util.Collections;
 import java.util.Locale;
 
 import external.org.apache.commons.io.IOUtils;
@@ -98,6 +100,7 @@ public class SSHD {
             sshd.setPort(ssdServerPort);
             sshd.setShellFactory(new ProcessShellFactory("bash", "sh"));
             sshd.setCommandFactory(new ScpCommandFactory());
+            sshd.setSubsystemFactories(Collections.singletonList(new SftpSubsystemFactory()));
             SecurityUtils.setKeyPairResourceParser(BouncyCastleKeyPairResourceParser.INSTANCE);
             sshd.setKeyPairProvider(new ClassLoadableResourceKeyPairProvider(SSHD.class.getClassLoader(), "assets/sshdroid.pem"));
             sshd.setPasswordAuthenticator(AcceptAllPasswordAuthenticator.INSTANCE);