Bug 451755

It works for me and I can use SFTP + RSA key in Dolphin.

Can you please try again (+ check that whether you can connect to the remote machine by `ssh remote_machine_ip` in terminal)? These links may be useful:
https://forum.kde.org/viewtopic.php?f=224&t=162165
https://old.reddit.com/r/X1ExtremeGen2Related/comments/h9cjc0/enable_kde_dolphin_to_open_a_remote_directory/

I have tried this many times.

Here is my .ssh stanza:

Host remotehost
    HostName hostname
    User user
    Port 1000
    IdentityFile ~/.ssh/id_rsa

When I try to setup a sftp connection (Dolphin->Remote->Network->Add New Network Folder->Secure shell (ssh)->Next:

- Enter the information into the form 
- Select protocol "sftp"
-Click "Save and Connect

The dialogue asks me:

Authentication Dialog
Passphrase
Password.

It is asking me for a password for the account it did not recognize I was using an rsa key.

If I select cancel, it returns me to the form,
- Change protocol to fish
- Keep all other settings the same

The dialogue asks me:

SSH Authentication
Enter passphrase for key /home/user/.ssh/id_rsa.

If I enter my key passphrase it works.

** The dialogue box that comes up when selecting sftp is different than when selecting fish. Fish works, sftp does not work.** 

Even though I am using the same server information, when selecting sftp it does not recognize the key. When just changing this protocol to fish it works as expected.

Yes I can connect with the terminal.
Yes the key is in authorized keys.

The problem is quite specific, if I change the protocol from fish to sftp it does not work. With fish it works as expected.

Are you using any SSH agent? [1]

[1] https://wiki.archlinux.org/title/SSH_keys#SSH_agents

Yes I am using whatever the default agent is with KDE Neon (5.24.3), I believe it is the OpenSSH "ssh-agent"

Do you have a good understanding of the issue I am trying to describe? When I use the Dolphin "Add Network Folder" button to try to setup an 'sftp' connection, it doesn't recognize I am using a rsa key and it asks for an account password.

If I use the same button, with the same config stanza (~/.ssh/config) but change the protocol to 'fish' it recognizes and uses the rsa key.

So I can successfully set up a network folder using fish but not using sftp.

Yes, I understand your issue well.

I tried to reproduce your issue by setting up KDE on a _fresh_ install of Arch Linux.
The key is a RSA key, and I used "Add Network Folder" in Dolphin button to setup SFTP connection.

Unfortunately I am unable to reproduce your issue, so perhaps you will have to wait until other users or a developer figures out why this bug happens.

I have the same problem. I am asked for a user password instead of the key password. Using sftp from commandline works fine.

kde-neon: 20.04
plasma: 5.24.4
dolphin: 21.12.3

.ssh/config:
<code>
Host *
        ServerAliveInterval 60
        ServerAliveCountMax 10
        TCPKeepAlive yes

IdentityFile /home/<login>/.ssh/id_ed25519
</code>

<code>
~$ ps x | grep ssh-agent
   2587 ?        Ss     0:00 /usr/bin/ssh-agent /usr/bin/im-launch /usr/bin/startplasma-x11
</code>

Changing protocol to fish asks for key password but fails: "Unable to connect to server. Please check your settings and try again."

<code>
killall ssh-agent
</code>
and having it "<defunct>" does not change anything.

Same here. I use ssh-agent. When trying to log in with commandline ssh, I have no problems but when I use sftp:// in dolphin I'm asked for password. I'm sure it worked with no problems several weeks ago.

Operating System: Manjaro Linux
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Kernel Version: 6.0.0-1-MANJARO (64-bit)
Graphics Platform: X11
Processors: 12 × Intel® Core™ i7-9850H CPU @ 2.60GHz
Memory: 31.1 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 630
Manufacturer: Dell Inc.
Product Name: Latitude 5501

So 3 years later this function is still broken. It is not confined to KDE Neon, it is also broken in Kubuntu 24.04.2.

After 3 years no KDE developers have been assigned to this bug let alone bothered to even reply to the user here who have confirmed it? Why introduce new features that are broken out of the box and then leave them broken for many years. Does KDE Dolphin have any developers or is it basically abandonware at this point?

So further testing, if I start Dolphin from the terminal- "dolphin" then I can access my sftp:// remote share. It successfully reads ~/.ssh/config, finds the entry, reads the IdentityFile directive, queries the ssh-agent for the key and successfully opens the share. Note: dolphin does not open with any of the user settings such as color scheme.

When the same sftp:// remote share is accessed from Dolphin which is run from the plasma desktop (i.e. the icon) it erroneously prompts the user for a passphrase. i.e. it does not recognize that an rsa key is being used. It does however read the port from the ~/.ssh/config file so likely the problem is that dolphin it is not able to access the ssh-agent when an sftp remote share is being called.

Note: changing the share protocol to fish:// works as expected but sftp:// does not work.