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Merged
kruton merged 10 commits into from
Apr 28, 2026
Merged

Add SFTP client support (draft-ietf-secsh-filexfer) #112

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983f0f5
Add SFTP client support (draft-ietf-secsh-filexfer)
GlassOnTin Apr 5, 2026
d3e2353
Fix spotless formatting
GlassOnTin Apr 5, 2026
0536bc6
Refactor SFTP API to use sealed SftpResult instead of exceptions
GlassOnTin Apr 6, 2026
f8dbd41
Fix spotless formatting
GlassOnTin Apr 6, 2026
712dd04
Address review: sealed results for SFTP, fix imports
GlassOnTin Apr 6, 2026
811a145
Address review: convert SftpPacketIO to sealed-result return
GlassOnTin Apr 25, 2026
06f8d69
Run spotlessApply
GlassOnTin Apr 25, 2026
f5a1226
Fix SFTP integration test OPENSSH_VERSION (tag name → tarball name)
GlassOnTin Apr 25, 2026
4ac6898
Grow Kaitai serialization buffer on overflow
GlassOnTin Apr 25, 2026
9057e91
Retrigger CI
GlassOnTin Apr 26, 2026
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29 changes: 24 additions & 5 deletions protocol/src/main/kotlin/org/connectbot/sshlib/protocol/KaitaiUtils.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -21,12 +21,31 @@ import io.kaitai.struct.KaitaiStruct

/**
* Serialize a Kaitai struct to a byte array.
*
* Kaitai's [ByteBufferKaitaiStream] is fixed-capacity, so the underlying
* `ByteBuffer.put` throws [java.nio.BufferOverflowException] if the
* pre-allocated buffer is too small. We don't have a cheap way to know
* the encoded size up front, so start at 16 KiB and double on overflow
* until the message fits or we cross [MAX_BUFFER]. Most SSH messages
* encode in well under 16 KiB; this only matters for [SshMsgChannelData]
* carrying near-`maxPacketSize` (32 KiB) of data — e.g. SFTP transfers.
*/
fun KaitaiStruct.ReadWrite.toByteArray(): ByteArray {
_check()
val io = ByteBufferKaitaiStream(1024 * 16)
_write(io)
val size = io.pos()
io.seek(0)
return io.readBytes(size.toLong())
var capacity = INITIAL_BUFFER
while (true) {
try {
val io = ByteBufferKaitaiStream(capacity)
_write(io)
val size = io.pos()
io.seek(0)
return io.readBytes(size.toLong())
} catch (_: java.nio.BufferOverflowException) {
if (capacity >= MAX_BUFFER) throw IllegalStateException("Kaitai message exceeds $MAX_BUFFER byte serialization limit")
capacity = minOf(capacity * 2, MAX_BUFFER)
}
}
}

private const val INITIAL_BUFFER = 1024L * 16
private const val MAX_BUFFER = 1024L * 1024
176 changes: 176 additions & 0 deletions sshlib/api.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -230,6 +230,180 @@ package org.connectbot.sshlib {
property public String type;
}

public final class SftpAttributes {
ctor public SftpAttributes();
ctor public SftpAttributes(optional java.lang.Long? size, optional java.lang.Integer? uid, optional java.lang.Integer? gid, optional java.lang.Integer? permissions, optional java.lang.Integer? atime, optional java.lang.Integer? mtime);
method public java.lang.Long? component1();
method public java.lang.Integer? component2();
method public java.lang.Integer? component3();
method public java.lang.Integer? component4();
method public java.lang.Integer? component5();
method public java.lang.Integer? component6();
method public org.connectbot.sshlib.SftpAttributes copy(optional java.lang.Long? size, optional java.lang.Integer? uid, optional java.lang.Integer? gid, optional java.lang.Integer? permissions, optional java.lang.Integer? atime, optional java.lang.Integer? mtime);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public java.lang.Integer? getAtime();
method @InaccessibleFromKotlin public java.lang.Integer? getGid();
method @InaccessibleFromKotlin public java.lang.Integer? getMtime();
method @InaccessibleFromKotlin public java.lang.Integer? getPermissions();
method @InaccessibleFromKotlin public java.lang.Long? getSize();
method @InaccessibleFromKotlin public java.lang.Integer? getUid();
method public int hashCode();
method public java.lang.String toString();
property public Integer? atime;
property public Integer? gid;
property public Integer? mtime;
property public Integer? permissions;
property public Long? size;
property public Integer? uid;
field public static final org.connectbot.sshlib.SftpAttributes.Companion Companion;
}

public static final class SftpAttributes.Companion {
method @InaccessibleFromKotlin public org.connectbot.sshlib.SftpAttributes getEMPTY();
property public org.connectbot.sshlib.SftpAttributes EMPTY;
}

public interface SftpClient {
method public void close();
method public suspend java.lang.Object? close(org.connectbot.sshlib.SftpFileHandle handle, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? fsetstat(org.connectbot.sshlib.SftpFileHandle handle, org.connectbot.sshlib.SftpAttributes attrs, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? fstat(org.connectbot.sshlib.SftpFileHandle handle, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<org.connectbot.sshlib.SftpAttributes>>);
method @InaccessibleFromKotlin public int getProtocolVersion();
method @InaccessibleFromKotlin public boolean isOpen();
method public default suspend java.lang.Object? listdir(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<? extends java.util.List<org.connectbot.sshlib.SftpDirectoryEntry>>>);
method public suspend java.lang.Object? lstat(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<org.connectbot.sshlib.SftpAttributes>>);
method public suspend java.lang.Object? mkdir(java.lang.String path, optional org.connectbot.sshlib.SftpAttributes attrs, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? open(java.lang.String path, java.util.Set<? extends org.connectbot.sshlib.SftpOpenFlag> flags, optional org.connectbot.sshlib.SftpAttributes attrs, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<org.connectbot.sshlib.SftpFileHandle>>);
method public suspend java.lang.Object? opendir(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<org.connectbot.sshlib.SftpFileHandle>>);
method public suspend java.lang.Object? read(org.connectbot.sshlib.SftpFileHandle handle, long offset, int length, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<byte[]?>>);
method public suspend java.lang.Object? readdir(org.connectbot.sshlib.SftpFileHandle handle, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<? extends java.util.List<org.connectbot.sshlib.SftpDirectoryEntry>?>>);
method public suspend java.lang.Object? readlink(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<java.lang.String>>);
method public suspend java.lang.Object? realpath(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<java.lang.String>>);
method public suspend java.lang.Object? remove(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? rename(java.lang.String oldPath, java.lang.String newPath, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? rmdir(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? setstat(java.lang.String path, org.connectbot.sshlib.SftpAttributes attrs, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? stat(java.lang.String path, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<org.connectbot.sshlib.SftpAttributes>>);
method public suspend java.lang.Object? symlink(java.lang.String targetPath, java.lang.String linkPath, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
method public suspend java.lang.Object? write(org.connectbot.sshlib.SftpFileHandle handle, long offset, byte[] data, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<kotlin.Unit>>);
property public abstract boolean isOpen;
property public abstract int protocolVersion;
}

public final class SftpDirectoryEntry {
ctor public SftpDirectoryEntry(java.lang.String filename, java.lang.String longname, org.connectbot.sshlib.SftpAttributes attrs);
method public java.lang.String component1();
method public java.lang.String component2();
method public org.connectbot.sshlib.SftpAttributes component3();
method public org.connectbot.sshlib.SftpDirectoryEntry copy(optional java.lang.String filename, optional java.lang.String longname, optional org.connectbot.sshlib.SftpAttributes attrs);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public org.connectbot.sshlib.SftpAttributes getAttrs();
method @InaccessibleFromKotlin public java.lang.String getFilename();
method @InaccessibleFromKotlin public java.lang.String getLongname();
method public int hashCode();
method public java.lang.String toString();
property public org.connectbot.sshlib.SftpAttributes attrs;
property public String filename;
property public String longname;
}

public final class SftpException extends org.connectbot.sshlib.SshException {
ctor public SftpException(org.connectbot.sshlib.SftpStatusCode statusCode, java.lang.String message, optional java.lang.Throwable? cause);
method @InaccessibleFromKotlin public org.connectbot.sshlib.SftpStatusCode getStatusCode();
method public java.lang.String toString();
property public org.connectbot.sshlib.SftpStatusCode statusCode;
}

public final class SftpFileHandle {
method public boolean equals(java.lang.Object? other);
method public int hashCode();
}

public enum SftpOpenFlag {
method @InaccessibleFromKotlin public int getValue();
property public int value;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag APPEND;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag CREATE;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag EXCLUDE;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag READ;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag TRUNCATE;
enum_constant public static final org.connectbot.sshlib.SftpOpenFlag WRITE;
}

public sealed exhaustive interface SftpResult<T> {
}

public static final class SftpResult.IoError implements org.connectbot.sshlib.SftpResult {
ctor public SftpResult.IoError(java.lang.Throwable cause);
method public java.lang.Throwable component1();
method public org.connectbot.sshlib.SftpResult.IoError copy(optional java.lang.Throwable cause);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public java.lang.Throwable getCause();
method public int hashCode();
method public java.lang.String toString();
property public Throwable cause;
}

public static final class SftpResult.ProtocolError implements org.connectbot.sshlib.SftpResult {
ctor public SftpResult.ProtocolError(java.lang.String message);
method public java.lang.String component1();
method public org.connectbot.sshlib.SftpResult.ProtocolError copy(optional java.lang.String message);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public java.lang.String getMessage();
method public int hashCode();
method public java.lang.String toString();
property public String message;
}

public static final class SftpResult.ServerError implements org.connectbot.sshlib.SftpResult {
ctor public SftpResult.ServerError(org.connectbot.sshlib.SftpStatusCode statusCode, java.lang.String message);
method public org.connectbot.sshlib.SftpStatusCode component1();
method public java.lang.String component2();
method public org.connectbot.sshlib.SftpResult.ServerError copy(optional org.connectbot.sshlib.SftpStatusCode statusCode, optional java.lang.String message);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public java.lang.String getMessage();
method @InaccessibleFromKotlin public org.connectbot.sshlib.SftpStatusCode getStatusCode();
method public int hashCode();
method public java.lang.String toString();
property public String message;
property public org.connectbot.sshlib.SftpStatusCode statusCode;
}

public static final class SftpResult.Success<T> implements org.connectbot.sshlib.SftpResult<T> {
ctor public SftpResult.Success(T value);
method public T component1();
method public org.connectbot.sshlib.SftpResult.Success<T> copy(optional T value);
method public boolean equals(java.lang.Object? other);
method @InaccessibleFromKotlin public T getValue();
method public int hashCode();
method public java.lang.String toString();
property public T value;
}

public final class SftpResultKt {
method public static <T> T? getOrNull(org.connectbot.sshlib.SftpResult<? extends T>);
method public static <T> T getOrThrow(org.connectbot.sshlib.SftpResult<? extends T>);
}

public enum SftpStatusCode {
method @InaccessibleFromKotlin public int getCode();
property public int code;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode BAD_MESSAGE;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode CONNECTION_LOST;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode EOF;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode FAILURE;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode NO_CONNECTION;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode NO_SUCH_FILE;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode OK;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode OP_UNSUPPORTED;
enum_constant public static final org.connectbot.sshlib.SftpStatusCode PERMISSION_DENIED;
field public static final org.connectbot.sshlib.SftpStatusCode.Companion Companion;
}

public static final class SftpStatusCode.Companion {
method public org.connectbot.sshlib.SftpStatusCode fromCode(int code);
}

public interface Socks5Authenticator {
method public boolean authenticate(java.lang.String username, java.lang.String password);
}
Expand All @@ -254,6 +428,7 @@ package org.connectbot.sshlib {
method public suspend java.lang.Object? localPortForward(int bindPort, java.lang.String remoteHost, int remotePort, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.PortForwarder?>);
method public org.connectbot.sshlib.transport.TransportFactory? openDirectTcpipTransport(java.lang.String remoteHost, int remotePort, optional java.lang.String originAddr, optional int originPort);
method public suspend java.lang.Object? openSession(kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SshSession?>);
method public suspend java.lang.Object? openSftp(kotlin.coroutines.Continuation<? super org.connectbot.sshlib.SftpResult<? extends org.connectbot.sshlib.SftpClient>>);
method public suspend java.lang.Object? remotePortForward(java.lang.String remoteBindAddress, int remoteBindPort, java.lang.String localHost, int localPort, kotlin.coroutines.Continuation<? super org.connectbot.sshlib.PortForwarder?>);
property public kotlinx.coroutines.flow.SharedFlow<java.lang.Throwable?> disconnectedFlow;
property public boolean isAuthenticated;
Expand Down Expand Up @@ -419,6 +594,7 @@ package org.connectbot.sshlib.blocking {
method public org.connectbot.sshlib.transport.TransportFactory? openDirectTcpipTransport(java.lang.String remoteHost, int remotePort, optional java.lang.String originAddr);
method public org.connectbot.sshlib.transport.TransportFactory? openDirectTcpipTransport(java.lang.String remoteHost, int remotePort, optional java.lang.String originAddr, optional int originPort);
method public org.connectbot.sshlib.SshSession? openSession();
method @kotlin.jvm.Throws(exceptionClasses=SftpException::class) public org.connectbot.sshlib.SftpClient openSftp() throws org.connectbot.sshlib.SftpException;
method public org.connectbot.sshlib.PortForwarder? remotePortForward(java.lang.String remoteBindAddress, int remoteBindPort, java.lang.String localHost, int localPort);
property public kotlinx.coroutines.flow.SharedFlow<java.lang.Throwable?> disconnectedFlow;
property public boolean isAuthenticated;
Expand Down
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