connection-sftp | VisualCron Documentation

Connection - SFTP

The SFTP Connection stores connect and logon properties for the transfer protocol SSH File Transfer Protocol (SFTP).

About SFTP

SFTP (SSH File Transfer Protocol, often called Secure File Transfer Protocol) is a protocol that lets you transfer files securely over a SSH connection. SFTP is not compatible with FTP (File Transfer Protocol), which has it's own security enhancements such as FTPS, FTP over SSL. SFTP is built on top of SSH connection. SSH supports various authentication schemes such as password-based and public key. Public key authentication requires a private key which can be linked to from the Security tab. The VisualCron implementation supports 3-5 of SFTP protocol (versions 1, 2 are outdated and not used anywhere). Default port for SFTP is 22.

Manage Connections > Add > SFTP > Authentication tab

Authentication type

Authentication type can either by Password or Public key. For the FTP protocol only password authentication is available. When using SFTP together with public key authentication you have to specify a path to a private key file.

Username

The user name for the connection.

Password

The password for the connection.

Public key vs password authentication

Public key authentication means that you specify the private key and any password for that key. Private keys can be loaded in SSH1, OpenSSH, Binary, Putty, IETF (Putty and IETF use different formats here) formats.

Private key group

These options are only used when using Public key authentication.

Private key path

This is the private key you have received from server administrator. Click the File icon to browse for the private key.

Password

The password for the public key.

Override authentication

By authentication, normally both Password and Keyboard authentication are suggested. Some servers do not support the VisualCron Auto authentication. Uncheck this and check the specified type of authentication you want to use.

Manage Connections > Add > SFTP > Encryption tab

Some SFTP servers require specific encryption for communication between Client and Server. 4 types of encryption can be adjusted in VisualCron:

Encryption algorithm
Key exchange algorithm
MAC algorithm
Public key algorithms

By default, these are auto-negotiated by VisualCron but sometimes the remote server does provide the proper information to VisualCron and you need to, in detail, adjust which algorithms should be used. For each encryption type you can check "Auto adjust ciphers". When checked, VisualCron will try to find the right setting. If you uncheck you can select yourself.

For any issues with auto-setting please refer to the Other Connection error->Set correct Encryption settings section below.

Manage Connections > Add > SFTP > Extra settings tab

Transfer type

Select if you want to transfer through binary (default) or ASCII mode.

Sync data channel

FTP only option. This option specifies whether to synchronize data channel. Switch it on if component hangs when trying to establish data connection, i.e., on using commands list, upload, download.

Data connection type

FTP only option.

Max packet size

Use this property to specify the maximal length of packet in bytes. The default value is 262144, i.e., 256 KBytes.

Auto adjust transfer block

Use this property to enable or disable automatic adjustment of pipeline length and block sizes. By default automatic adjustment is enabled, and normally you don't need to disable it.

Pipeline length

Use this property to specify the number of upload or download requests sent before waiting for all requests to complete. The more requests are sent, the faster the transfer is. However, in case of error, all requests are discarded. Also, more pending requests means more memory used, so if speed is not critical and memory consumption is, set PipelineLength to 1. Default value is 10.

Download block size

Use this property to control the size of the single download request in bytes. The servers don't limit download request size, however the buffer is allocated to store the requests, so the larger the value is, the memory block is needed. If you have download speed problems you can try to set to 0 (which is automatic handling), alternatively if you are transferring large files you can use a value up to 2Mb (2097152).

Upload block size

Use this property to control the size of the single upload request in bytes. The servers don't limit upload request size, however the buffer is allocated to store the requests, so the larger the value is, the memory block is needed. If you have upload speed problems you can try to set to 0 (which is automatic handling), alternatively if you are transferring large files you can use a value up to 2Mb (2097152).

SFTP version support

Some SFTP servers do not support connections with specific SFTP versions. You can control in details what SFTP client versions that should be supported. http://en.wikipedia.org/wiki/SSH_File_Transfer_Protocol

Troubleshooting

Authentication types:

2 - public key authentication
4 - password authentication
16 - keyboard-interactive authentication

Authentication type 16 failed along with error 114

Try unchecking "Auto authentication" along with unchecking "Password authentication". The problem could also be that password or username is wrong.

Authentication type 4 failed along with error 114

Try unchecking "Auto authentication" along with unchecking "Keyboard authentication". The problem could also be that password or username is wrong.

Authentication type 2 failed along with error 114

Public key authentication is failing - maybe you are using the wrong private key or server uses password authentication.

Authentication failed for type 16 and 4 along with error 114

Currently you are using password authentication but it seems like the server requires public key authentication.

SFTP error 6

A pseudo-error which indicates that the client has no connection to the server

SFTP error 7 in combination with error 10058

Try unchecking Auto adjust MAC algorithms in Connection->Encryption. See Other Connection error->Set correct Encryption settings

SFTP error 11 in combination with error 10058

Try these solutions, one at a time:

open Authentication tab of Connection and uncheck "Auto authentication" and uncheck "Keyboard authentication".
open Encryption tab of Connection and uncheck "Auto adjust ciphers"

SFTP error 96273 / Failed to retrieve file list: SFTP component not connected

Possible causes;

Wrong key exchange algorithm is used. See Other Connection error->Set correct Encryption settings.
Alternatively try setting one SFTP version at a time, starting from 2, ending at 6.
Username is empty
If the Connection Explorer is working but Task not please check Task settings. Make sure that you use the correct directory back slash for example: . We recommend that you use the button for selection instead of typing folders manually.

SFTP error 96258

Please make sure that you selected a private key if needed.

SFTP error 102

Go to Connection->Extra settings and alter these values:

Max packet size: 8096 Pipeline length: 16 Download block size: 2048 Upload block size: 2048

SFTP error 103

Wrong key exchange or mac algorithm is used. See Other Connection error->Set correct Encryption settings

SFTP error 10061

Try checking Encryption->Use compression. Also see Other Connection error->Set correct Encryption settings

Failed to upload/download full file (only part) (SFTP component not connected) / timeout when upload

If only part of file is uploaded or downloaded (or only small files are fully transferred) you can try to uncheck Auto adjust transfer block in Extra settings of the Connection. If you are having upload issues you can also increase Upload block size to 65536.You can also try to set Pipeline length to 1.

Other error codes

https://www.secureblackbox.com/kb/help/ref_err_sftperrorcodes.html

Public key errors

3329 (0x0D01) Public key is invalid - usually indicate that there is something wrong with the format of the file
3330 (0x0D02) Private key is invalid - usually indicate that there is something wrong with the format of the file
3331 (0x0D03) Error of reading from file
3332 (0x0D04) Error of writing to file
3333 (0x0D05) Algorithm is unsupported
3334 (0x0D06) Internal error
3335 (0x0D07) Buffer is too small
3336 (0x0D08) There is no private key
3337 (0x0D09) Wrong password for private key
3338 (0x0D0A) PEM algorithm is unsupported

Other Connection error->Set correct Encryption settings

OPTION 1