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Inspiring
November 14, 2023
Question

CF2018 / CF2021 sFTP fail - Algorithm negotiation fail

  • November 14, 2023
  • 2 replies
  • 825 views

We connect to a partner organization daily to grab sets of files using sFTP.  We had received notice from them that they were deprecating ssh-rsa and only supporting rsa-sha2-256 and rsa-sha2-512 going forward.  Well the day has come and apparently CF2018 (and 2021) using ssh-rsa as our connections have failed. 

 

There's nothing in any documents or articles that we can find about switching, forcing or upgrading the CFFTP algorithm other than some bugs with CF2011 and a zlib jar. 

 

Any help or ideas on how to get around this? 

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    2 replies

    BKBK
    Community Expert
    Community Expert
    April 5, 2024

    What error message do you get?

    Inspiring
    April 24, 2024

    We ended up switching to JSch (http://www.jcraft.com/jsch/) which supports more modern protocols than CF's built in sFTP capabilities.  Not only did they require us to switch to rsa-sha2-512, but also they're going to allow only hmac-sha2-256 and hmac-sha2-512 for handshakes going forward - something else that it seems ACF sFTP doens't support (or isn't documented)

    BKBK
    Community Expert
    Community Expert
    April 24, 2024

    Thanks for the update and for sharing your insight. 

    Inspiring
    November 14, 2023

    When connecting with CoreFTP, the connection is:

    SH-2.0-SSHD  
    diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group15-sha512,diffie-hellman-group16-sha512,diffie-hellman-group17-sha512,diffie-hellman-group18-sha512,rsa2048-sha256,ecdh-sha2-nistp384,ext-info-s
    diffie-hellman-group-exchange-sha256
    rsa-sha2-512
    ciphers selected: 
    aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-cbc,blowfish-cbc,rijndael128-cbc,rijndael192-cbc,rijndael256-cbc,rijndael-cbc@lysator.liu.se,des-cbc,des-cbc@ssh.com
    client->server cipher: aes256-ctr
    client->server mac: hmac-sha2-256
    server->client cipher: aes256-ctr
    server->client mac: hmac-sha2-256 
    SHA1 23:0b:3e:35:a6:85:78:77:fd:a2:bb:13:a6:34:8a:98:05:8b:08:8b
    sending password...
    PWD  
    Current directory is '/'