Error on SFTP/SSH Connect

Support
1

When attempting to connect to a server I receive the following:

Error: Failed to negotiate key exchange algorithm.
Source: action "File transfer", table "Table 1"

I can't find a way around this.

2

What EasyMorph version are you using?

3

I am using the following:

EasyMorph version: 4.7.1.14 (bb38ea, 'Release')

4

We will check if SSH can now require new ciphers that are currently not supported by EasyMorph.

If you can tell us what algorithms are expected by the SSH service you’re connecting to, that would be very helpful.

5

On an odd flavor of linux

ssh -Q cipher returns this

3des-cbc
aes128-cbc
aes192-cbc
aes256-cbc
rijndael-cbc@lysator.liu.se
aes128-ctr
aes192-ctr
aes256-ctr
aes128-gcm@openssh.com
aes256-gcm@openssh.com
chacha20-poly1305@openssh.com

6

Hi @MinnesotaJoe
You mention above that error was “Failed to negotiate key exchange algorithm”.
Could you please specify also a list of Key Algorithms and Key Exchange Method?
It could be done via
ssh -Q key and ssh -Q kex

7

Here you go

# ssh -Q key
ssh-ed25519
ssh-ed25519-cert-v01@openssh.com
ssh-rsa
ssh-dss
ecdsa-sha2-nistp256
ecdsa-sha2-nistp384
ecdsa-sha2-nistp521
ssh-rsa-cert-v01@openssh.com
ssh-dss-cert-v01@openssh.com
ssh-rsa-cert-v01@openssh.com
ssh-dss-cert-v01@openssh.com
ecdsa-sha2-nistp256-cert-v01@openssh.com
ecdsa-sha2-nistp384-cert-v01@openssh.com
ecdsa-sha2-nistp521-cert-v01@openssh.com
# ssh -Q kex
diffie-hellman-group1-sha1
diffie-hellman-group14-sha1
diffie-hellman-group14-sha256
diffie-hellman-group16-sha512
diffie-hellman-group18-sha512
diffie-hellman-group-exchange-sha1
diffie-hellman-group-exchange-sha256
ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
curve25519-sha256
curve25519-sha256@libssh.org
8

@MinnesotaJoe, can you please try the new version 4.7.2 that has just been published: Download free ETL tool | EasyMorph

9

Hi @MinnesotaJoe,

Has updating to the newer version resolved the issue?

10

I’d just add more details for further usage.
To see enabled in OpenSSH Daemon (sshd) KexAlgorithms (key exchange algorithm), ciphers and macs should use command

sshd -T | grep "\(ciphers\|macs\|kexalgorithms\)"

As of EasyMorph version 4.7.2

Supported Key Exchange Methods

    curve25519-sha256
    curve25519-sha256@libssh.org
    ecdh-sha2-nistp256
    ecdh-sha2-nistp384
    ecdh-sha2-nistp521
    diffie-hellman-group-exchange-sha256
    diffie-hellman-group-exchange-sha1
    diffie-hellman-group16-sha512
    diffie-hellman-group14-sha256
    diffie-hellman-group14-sha1
    diffie-hellman-group1-sha1

Ciphers (Encryption Methods)

    aes256-ctr
    3des-cbc
    aes128-cbc
    aes192-cbc
    aes256-cbc
    blowfish-cbc
    twofish-cbc
    twofish192-cbc
    twofish128-cbc
    twofish256-cbc
    arcfour
    arcfour128
    arcfour256
    cast128-cbc
    aes128-ctr
    aes192-ctr

MACs

    hmac-md5
    hmac-md5-96
    hmac-sha1
    hmac-sha1-96
    hmac-sha2-256
    hmac-sha2-256-96
    hmac-sha2-512
    hmac-sha2-512-96
    hmac-ripemd160
    hmac-ripemd160@openssh.com