SFTP connection issue: Can't open path: Could not connect to SFTP server

[DavidAccola]

Are there any known issues are quirks with connecting to SFTP? I am able to connect to a server over SFTP using WinSCP without issue, but not with OtrosLogViewer when using the same credentials. (FTP works fine, just not SFTP.)

Can't open path: Could not connect to SFTP server at "xxx.xxxxxxxxxxxxxx.com"

[svennissel]

Can you append the olv.log in home directory? Did you type before wrong username and password? Did it work after restart OtrosLogViewer?

[benlazaro]

I think this has to do with issue #608 as well (zip format). I tried reproducing your problem using a free public SFTP server and I was able to access a readme.txt file stored in the server without any issues.
Try connecting the "rebex" server from the following website: https://www.sftp.net/public-online-sftp-servers
If you are able to open the readme.txt file, then we will need to wait until issue #608 is resolved before we try to fix this one. The readme.txt file won't parse correctly in OLV, but I'm expecting you not to get the error message you're getting with zip file.
Let us know how the test went.

[DavidAccola]

@benlazaro Ha, my screenshot was misleading, sorry. This one doesn't have anything to do with .zip files, that's just the last thing I had up on my screen locally before I tried to connect to this SFTP server. Thanks for the test SFTP. Yes, I'm able to connect to test.rebex.net:22 without issue. Looks like the difference is the encryption algorithms each server uses.

@svennissel The username and password are right. It doesn't work after restart. I started fresh and have attached the log. What stands out is:

Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail

olv.log

test.rebex.net:22 which works uses ssh-ed25519 255
The server I'm trying to connect to and can't uses ssh-rsa 1024

[nuessgens]

@svennissel maybe one "just" have to add bouncy castle crypto dependency to support "latest" cipher suits/ algorithms which are not present in the currently used jdk version?

I'll try to reproduce it tomorrow.

[DavidAccola]

Doing some searching on that error, it could also be that this OtrosLogViewer uses Zlib compression and the SFTP server does not support Zlib compression. I haven't figured out how to check that yet (don't have any control over this SFTP server).

[nuessgens]

I created a pull-request #615

With this new ssh-algorithms are supported (e.g. ssh-ed25519)

@DavidAccola I'm not quite sure if this resolves your issue. I found the following in the jsch FAQ

As of the 0.2.0 release, the RSA/SHA1 signature algorithm is disabled by default.

If the server is using such signature algorithm maybe you can try starting OtrosLogViewer with the described system-properties to re-enable ssh-rsa

[DavidAccola]

Thanks for the info!

[svennissel]

@DavidAccola:
Can you run the following commands to get a list of supported algorithms
ssh -Q cipher
ssh -Q mac
ssh -Q kex
ssh -Q key
I have this commands from https://superuser.com/questions/868998/how-can-i-find-a-list-of-macs-ciphers-and-kexalgorithms-that-my-openssh-client

And try please this version included the fix of @nuessgens
https://drive.google.com/file/d/1Iuh9tSsoXKzwmsQB9MPYh2tA5V5zKkHQ/view?usp=sharing