1024 RSA keys failing at mm_answer_keyverify

[Manju Prabhu]

Hi,
I am trying to debug why, when I use 1024 size RSA keys, ssh from client
fails. The keys are copied fine. Permissions looks good. 2048 to 8192 sized
keys work fine.

I tried enabling logs, however, I am not able to understand the below
error. Attaching sshd_config and snipped log files.

auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug1: Client protocol version
2.0; client software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.8
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug1: match: OpenSSH_7.2p2
Ubuntu-4ubuntu2.8 pat OpenSSH* compat 0x04000000
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug1: Local version string
SSH-2.0-OpenSSH_7.6
<snip>
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_request_send
entering: type 23
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_sshkey_verify
entering [preauth]
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_request_send
entering: type 24 [preauth]
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_sshkey_verify:
waiting for MONITOR_ANS_KEYVERIFY [preauth]
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3:
mm_request_receive_expect entering: type 25 [preauth]
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_request_receive
entering [preauth]
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_request_receive
entering
auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: monitor_read: checking
request 24
*auth.debug: Apr 26 18:48:21 vm1 sshd[2442]: debug3: mm_answer_keyverify:
publickey 0x7f4120b43cd0 signature unverified*

Thanks,
Manju