failed to negotiate key exchange algorithm

matt_15 · 01-23-2015, 11:58 AM

Connected to a locked down server via SSH.. I get this in the queue.

Code:

[R] Connecting to LockedDownServer - 74.xx.xx.xx -> IP=74.xx.xx.xx PORT=22
[R] Connected to LockedDownServer - 74.xx.xx.xx
[R] SSH Error: failed to negotiate key exchange algorithm
[R] SSH Connection closed
[R] Connection failed

Connecting via terminal agent with advanced exchange methods turned off..

Code:

Key exchange failed.
No compatible key exchange method. The server supports these methods: curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256

Once I turn on the newer key exchange methods..

Code:

[LOCAL] : Available Remote Kex Methods = curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256 
[LOCAL] : Selected Kex Method = diffie-hellman-group-exchange-sha256 
[LOCAL] : Available Remote Host Key Algos = ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519 
[LOCAL] : Selected Host Key Algo = ssh-dss 
[LOCAL] : Available Remote Send Ciphers = chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr 
[LOCAL] : Selected Send Cipher = aes256-ctr 
[LOCAL] : Available Remote Recv Ciphers = chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr 
[LOCAL] : Selected Recv Cipher = aes256-ctr 
[LOCAL] : Available Remote Send Macs = hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-ripemd160-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160,umac-128@openssh.com 
[LOCAL] : Selected Send Mac = hmac-sha2-512 
[LOCAL] : Available Remote Recv Macs = hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-ripemd160-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160,umac-128@openssh.com 
[LOCAL] : Selected Recv Mac = hmac-sha2-512 
[LOCAL] : Available Remote Compressors = none,zlib@openssh.com 
[LOCAL] : Selected Compressor = none 
[LOCAL] : Available Remote Decompressors = none,zlib@openssh.com 
[LOCAL] : Selected Decompressor = none 
[LOCAL] : Changing state from STATE_EXPECT_KEX_INIT to STATE_KEY_EXCHANGE

Sorry for all that code copying. I think FFXP just needs some new Key Exchange Methods baked in. Maybe V5 has these, but I dont know where I would get it from.

Using Version 4.4.4 build 2046 from June 6, 2014.

It is licensed to me

Best program I ever bought! Thanks for any help you can provide.

ps.. if devs want my IP to test on.. pm me from admin account, I will be happy to provide IP details.

matt_15 · 01-23-2015, 12:09 PM

Nevermind.. V5 supports the connections.. duh. My bad. Feel free to delete this thread