could not settle on kex algorithm - SFTP connection failed

[raychiranjib1]

SFTP connection failed using Net::SFTP client. But it's working with Filezilla and sftp command.

sftp -i ~/.ssh/private_key.pub -P 16321 -oKexAlgorithms=diffie-hellman-group1-sha1 -c aes128-cbc user@host

Code Example:

require 'net/sftp'

sftp = Net::SFTP.start('hostname', 'user', password: '', port: 'port', keys: '~/.ssh/private_key.pub')
sftp.connect

Output:

Failed to connect to hostname: could not settle on kex algorithm

Server kex preferences: diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1
Client kex preferences: ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1

Is it possible to use any of these Server preferences kex algorithms instead?
Is there any way to define Net::SFTP to use local ssh config?

[brett-novu]

@raychiranjib1 , the Net::SFTP documentation says that you can use any Net::SSH option. According to VALID_OPTIONS in the Net::SSH documentation, :kex is included as one you can provide.

[brett-novu]

Also, it appears that Net::SSH uses the standard config files by default: https://rubydoc.info/gems/net-ssh/7.1.0/Net%2FSSH%2Estart