dropbear dbclient Received out-of-order kexdhreply error

Hi,

I have deployed AES-GCM as cipher in my server and the kex method are ecdh-sha2-nistp521
signing: ecdsa-sha2-nistp521
cipher suite: aes128-gcm@openssh.com

When I try to use dbclient to talk to my server I have encountered

Received out-of-order kexdhreply error

It works fine while using OpenSSH to talk to the server.

I did a deep investigations.

It seems like from the OpenSSH
the client side should follow this process:

SSH_MSG_KEXINIT
SSH_MSG_KEX_ECDH
SSH_MSG_NEWKEYS
SSH_MSG_SERVICE_ACCEPT

Somehow while using dbclient

It switches back to
SSH_MSG_KEXINIT after SSH_MSG_NEWKEYS so it never reaches SSH_MSG_SERVICE_ACCEPT

I have attached log below.

Any helps will be super grateful
Attached Files

dbclient-P521--kexdhreply-out-of-order.txt (5.5 KB)