ssh_connect fails: Received SSH_MSG_DISCONNECT 33554432:bad client public DH value

["Zvi Vered" <veredz72@xxxxxxxxx>]

Dear Members,

I ported libssh-0.6.3 and openssl-1.0.1g  to vxWorks 6.9.2 (with very few 
code changes).

Upon ssh_connect I got the messages listed below.

As you can see the connection fails and the final message is:

ssh_packet_disconnect_callback:  Received SSH_MSG_DISCONNECT 33554432:bad 
client public DH value

On the server side (running under RHEL 5.3) I got the following messages in 
/var/log/secure:

expecting SSH2_MSG_KEXDH_INIT
invalid public DH value (1 / 2048)
Disconnecting: bad client public DH value

What can cause this problem ?

Thanks,
Zvika

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-> [1970/01/01 00:00:00.000000, 1] ssh_connect:  libssh 0.6.3 (c) 2003-2014 
Aris Adamantiadis, Andreas Schneider, and libssh contributors. Distributed 
under the LGPL, please refer to COPYING file for information about your 
rights, using threading threads_noop
[1970/01/01 00:00:00.000064, 3] getai:  host 128.172.82.55 matches an IP 
address
[1970/01/01 00:00:00.000000, 2] ssh_socket_connect:  Nonblocking connection 
socket: 6
[1970/01/01 00:00:00.808925489, 2] ssh_connect:  Socket connecting, now 
waiting for the callbacks to work
[1974/09/05 19:44:04.145667616, 3] ssh_connect:  ssh_connect: Actual timeout 
: 10000
[2097/01/10 06:02:22.-286331154, 3] ssh_socket_pollcallback:  Received 
POLLOUT in connecting state
[2097/01/10 06:02:22.139554400, 1] socket_callback_connected:  Socket 
connection callback: 1 (0)
[1970/02/21 20:18:44.139848112, 3] callback_receive_banner:  Received 
banner: SSH-2.0-OpenSSH_4.3
[1974/09/05 19:43:04.000019, 1] ssh_client_connection_callback:  SSH server 
banner: SSH-2.0-OpenSSH_4.3
[1970/01/01 00:00:00.000000, 1] ssh_analyze_banner:  Analyzing banner: 
SSH-2.0-OpenSSH_4.3
[1974/06/07 14:41:52.147642244, 1] ssh_analyze_banner:  We are talking to an 
OpenSSH client version: 4.3 (40300)
[1970/01/01 00:00:00.000000, 3] ssh_socket_unbuffered_write:  Enabling 
POLLOUT for socket
[1970/01/01 00:17:04.131080, 3] ssh_packet_socket_callback:  packet: read 
type 20 [len=700,padding=7,comp=692,payload=692]
[1974/08/13 22:00:40.145663148, 3] ssh_packet_process:  Dispatching handler 
for packet type 20
[1970/02/23 18:37:26.147642212, 4] ssh_list_kex:  kex algos: 
diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  server host key algo: 
ssh-rsa,ssh-dss
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  encryption client->server: 
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  encryption server->client: 
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  mac algo client->server: 
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  mac algo server->client: 
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  compression algo 
client->server: none,zlib@xxxxxxxxxxx
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  compression algo 
server->client: none,zlib@xxxxxxxxxxx
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  languages client->server:
[1974/08/13 21:56:40.147642212, 4] ssh_list_kex:  languages server->client:
[1970/01/01 00:00:00.000000, 4] ssh_list_kex:  kex algos: 
diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  server host key algo: 
ssh-rsa,ssh-dss
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  encryption client->server: 
aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc,3des-cbc,des-cbc-ssh1
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  encryption server->client: 
aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc,3des-cbc,des-cbc-ssh1
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  mac algo client->server: 
hmac-sha1
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  mac algo server->client: 
hmac-sha1
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  compression algo 
client->server: none
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  compression algo 
server->client: none
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  languages client->server:
[1974/08/13 21:56:04.000000, 4] ssh_list_kex:  languages server->client:
[1974/08/13 21:36:36.000000, 3] packet_send2:  packet: wrote 
[len=364,padding=6,comp=357,payload=357]
[1974/08/13 21:55:44.145662852, 3] packet_send2:  packet: wrote 
[len=12,padding=5,comp=6,payload=6]
[1970/01/01 00:00:00.000000, 3] ssh_socket_unbuffered_write:  Enabling 
POLLOUT for socket
[1970/01/01 00:17:04.131080, 3] ssh_packet_socket_callback:  packet: read 
type 1 [len=44,padding=4,comp=39,payload=39]
[1974/08/13 22:00:40.145663148, 3] ssh_packet_process:  Dispatching handler 
for packet type 1
[1970/01/01 00:00:00.000000, 3] ssh_packet_disconnect_callback:  Received 
SSH_MSG_DISCONNECT 33554432:bad client public DH value
[1970/01/01 00:00:16.139880016, 1] ssh_packet_disconnect_callback:  Received 
SSH_MSG_DISCONNECT: 33554432:bad client public DH value
[1974/08/13 23:13:32.145667616, 3] ssh_connect:  ssh_connect: Actual state : 
9
ssh_connect failed: Received SSH_MSG_DISCONNECT: 33554432:bad client public 
DH value