I'm receiving 'Bad signature' when trying to connect to an SSH server, however I'm able to connect OK using OpenSSH. I'm hoping that somebody here can help me get to the bottom of this! Using twisted: $ python -m twisted.conch.scripts.conch -v xxx [-] Log opened. [-] Starting factory <twisted.conch.client.unix.SSHUnixClientFactory instance at 0x707a30> [-] Stopping factory <twisted.conch.client.unix.SSHUnixClientFactory instance at 0x707a30> [-] Starting factory <twisted.conch.client.direct.SSHClientFactory instance at 0x707a58> [SSHClientTransport,client] kex alg, key alg: diffie-hellman-group- exchange-sha1 ssh-rsa [SSHClientTransport,client] outgoing: aes256-cbc hmac-sha1 none [SSHClientTransport,client] incoming: aes256-cbc hmac-sha1 none [SSHClientTransport,client] Disconnecting with error, code 3 reason: bad signature [SSHClientTransport,client] connection lost [SSHClientTransport,client] Stopping factory <twisted.conch.client.direct.SSHClientFactory instance at 0x707a58> [-] Main loop terminated. Connection to xxx closed. conch: exiting with error [Failure instance: Traceback (failure with no frames): <class 'twisted.conch.error.ConchError'>: ('bad signature', 3) Using ssh (some lines removed for brevity): $ ssh -vvv xxx OpenSSH_5.1p1, OpenSSL 0.9.7l 28 Sep 2006 debug1: Remote protocol version 2.0, remote software version 0.0 debug1: no match: 0.0 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.1 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie- hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman- group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128- cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se ,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac- ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: diffie-hellman-group1-sha1,diffie-hellman- group-exchange-sha1 debug2: kex_parse_kexinit: ssh-rsa debug2: kex_parse_kexinit: aes256-cbc,aes192-cbc,aes128-cbc,twofish- cbc,blowfish-cbc,3des-cbc,arcfour debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96 debug2: kex_parse_kexinit: zlib,none debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: mac_setup: found hmac-md5 debug1: kex: server->client aes128-cbc hmac-md5 none debug2: mac_setup: found hmac-md5 debug1: kex: client->server aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug2: dh_gen_key: priv key bits set: 132/256 debug2: bits set: 515/1025 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug3: check_host_in_hostfile: filename /Users/jon/.ssh/known_hosts debug3: check_host_in_hostfile: match line 13 debug1: Host 'xxx' is known and matches the RSA host key. debug1: Found key in /Users/jon/.ssh/known_hosts:13 debug2: bits set: 521/1025 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /Users/jon/.ssh/id_rsa (0x107ec0) debug2: key: /Users/jon/.ssh/identity (0x0) debug2: key: /Users/jon/.ssh/id_dsa (0x0) debug3: input_userauth_banner