How can I specify which cipher lftp is using when connecting to a sftp server?

Question

I'm using lftp to connect to an sftp server but I get a "no matching ciphers" error, and need to specify which cipher is used.

Using sftp the command to connect would look like this:

sftp -c aes256-cbc sftp://sftpserver:10

How can I connect with that cipher using lftp? I can't find anything about ciphers or how to specify which encryption to use and let lftp pass it to ssh. I'm looking for something similar to sftp's option -o that passes and option to ssh.

Answer 1

Read man lftp and see set sftp:connect-program. Here's my example (a shell wrapper around lftp) from which you can get idea how to use it, in my case I used lftp to sftp via a jumpbox.

...
sshargs="ssh -F ${tmpdir}/.ssh/config -J "
sshargs+="${JUMPBOX_USER}@${JUMPBOX_HOST}"

export LFTP_HOME=${tmpdir}
cat > ${tmpdir}/rc <<EOF
set sftp:connect-program ${sshargs}
EOF

lftp -c "
open -u ${WEBSERVER_USER},whatever sftp://${WEBSERVER_HOST}${DEST_DIR}
cd ${SRC_DIR} && mirror --dry-run -R --ignore-size -L --no-perms --no-umask
bye
"