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