Hello, I would like to login on a client without a public IP using portforewarding. I thought I could do this by having one server with public IP where the client forewards its SSH port using: > ssh root@server -R 2222:server:22 That seems to work fine, sshd now listens on port 2222 on the server, and when I try to log in on client from the server: > ssh -l client_user -p 2222 127.0.0.1 However when I enter the password it fails with: >Permission denied, please try again. On the server with the public IP I use: OpenSSH_4.3p2 Debian-9, OpenSSL 0.9.8c 05 Sep 2006 On the client I use: OpenSSH_4.7p1, OpenSSL 0.9.8b 04 May 2006 Thank you in advance, Clemens 1. Complete debug output from the client, which forewards its ssh port to the server: [root@localhost ce]# ssh root@xxxxxxxxxxx -R 2222:78.78.78.78:22 -vvv OpenSSH_4.7p1, OpenSSL 0.9.8b 04 May 2006 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to 78.78.78.78 [78.78.78.78] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3p2 Debian-9 debug1: match: OpenSSH_4.3p2 Debian-9 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_4.7 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@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@xxxxxxxxxxx,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@xxxxxxxxxxx,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx,zlib debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx,zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: 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@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx debug2: kex_parse_kexinit: 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: 127/256 debug2: bits set: 509/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: match line 5 debug1: Host '78.78.78.78' is known and matches the RSA host key. debug1: Found key in /root/.ssh/known_hosts:5 debug2: bits set: 550/1024 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: /root/.ssh/identity ((nil)) debug2: key: /root/.ssh/id_rsa ((nil)) debug2: key: /root/.ssh/id_dsa ((nil)) debug1: Authentications that can continue: publickey,password debug3: start over, passed a different list publickey,password debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Trying private key: /root/.ssh/identity debug3: no such identity: /root/.ssh/identity debug1: Trying private key: /root/.ssh/id_rsa debug3: no such identity: /root/.ssh/id_rsa debug1: Trying private key: /root/.ssh/id_dsa debug3: no such identity: /root/.ssh/id_dsa debug2: we did not send a packet, disable method debug3: authmethod_lookup password debug3: remaining preferred: ,password debug3: authmethod_is_enabled password debug1: Next authentication method: password root@xxxxxxxxxxx's password: debug3: packet_send2: adding 64 (len 59 padlen 5 extra_pad 64) debug2: we sent a password packet, wait for reply debug1: Authentication succeeded (password). debug1: Remote connections from LOCALHOST:2222 forwarded to local address 78.78.78.78:22 debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug1: Entering interactive session. debug1: remote forward success for: listen 2222, connect 78.78.78.78:22 debug2: callback start debug2: client_session2_setup: id 0 debug2: channel 0: request pty-req confirm 0 debug3: tty_make_modes: ospeed 38400 debug3: tty_make_modes: ispeed 38400 debug3: tty_make_modes: 1 3 debug3: tty_make_modes: 2 28 debug3: tty_make_modes: 3 127 debug3: tty_make_modes: 4 21 debug3: tty_make_modes: 5 4 debug3: tty_make_modes: 6 0 debug3: tty_make_modes: 7 0 debug3: tty_make_modes: 8 17 debug3: tty_make_modes: 9 19 debug3: tty_make_modes: 10 26 debug3: tty_make_modes: 12 18 debug3: tty_make_modes: 13 23 debug3: tty_make_modes: 14 22 debug3: tty_make_modes: 18 15 debug3: tty_make_modes: 30 0 debug3: tty_make_modes: 31 0 debug3: tty_make_modes: 32 0 debug3: tty_make_modes: 33 0 debug3: tty_make_modes: 34 0 debug3: tty_make_modes: 35 0 debug3: tty_make_modes: 36 1 debug3: tty_make_modes: 37 0 debug3: tty_make_modes: 38 0 debug3: tty_make_modes: 39 0 debug3: tty_make_modes: 40 0 debug3: tty_make_modes: 41 0 debug3: tty_make_modes: 50 1 debug3: tty_make_modes: 51 1 debug3: tty_make_modes: 52 0 debug3: tty_make_modes: 53 1 debug3: tty_make_modes: 54 1 debug3: tty_make_modes: 55 1 debug3: tty_make_modes: 56 0 debug3: tty_make_modes: 57 0 debug3: tty_make_modes: 58 0 debug3: tty_make_modes: 59 1 debug3: tty_make_modes: 60 1 debug3: tty_make_modes: 61 1 debug3: tty_make_modes: 62 0 debug3: tty_make_modes: 70 1 debug3: tty_make_modes: 71 0 debug3: tty_make_modes: 72 1 debug3: tty_make_modes: 73 0 debug3: tty_make_modes: 74 0 debug3: tty_make_modes: 75 0 debug3: tty_make_modes: 90 1 debug3: tty_make_modes: 91 1 debug3: tty_make_modes: 92 0 debug3: tty_make_modes: 93 0 debug1: Sending environment. debug3: Ignored env SSH_AGENT_PID debug3: Ignored env KDE_MULTIHEAD debug3: Ignored env HOSTNAME debug3: Ignored env GPG_AGENT_INFO debug3: Ignored env XDG_MENU_PREFIX debug3: Ignored env SHELL debug3: Ignored env TERM debug3: Ignored env XDG_SESSION_COOKIE debug3: Ignored env HISTSIZE debug3: Ignored env GTK2_RC_FILES debug3: Ignored env GS_LIB debug3: Ignored env GTK_RC_FILES debug3: Ignored env WINDOWID debug3: Ignored env QTDIR debug3: Ignored env QTINC debug3: Ignored env KDE_FULL_SESSION debug3: Ignored env USER debug3: Ignored env LS_COLORS debug3: Ignored env CCACHE_DIR debug3: Ignored env SSH_AUTH_SOCK debug3: Ignored env GNOME_KEYRING_SOCKET debug3: Ignored env USERNAME debug3: Ignored env SESSION_MANAGER debug3: Ignored env KONSOLE_DCOP debug3: Ignored env DESKTOP_SESSION debug3: Ignored env PATH debug3: Ignored env MAIL debug3: Ignored env GDM_XSERVER_LOCATION debug3: Ignored env PWD debug3: Ignored env INPUTRC debug3: Ignored env KONSOLE_DCOP_SESSION debug3: Ignored env CCACHE_UMASK debug3: Ignored env KDE_SESSION_UID debug3: Ignored env GNOME_KEYRING_PID debug1: Sending env LANG = de_DE.UTF-8 debug2: channel 0: request env confirm 0 debug3: Ignored env KDE_IS_PRELINKED debug3: Ignored env GDM_LANG debug3: Ignored env KDEDIRS debug3: Ignored env GDMSESSION debug3: Ignored env SSH_ASKPASS debug3: Ignored env HOME debug3: Ignored env SHLVL debug3: Ignored env SDL_AUDIODRIVER debug3: Ignored env XCURSOR_THEME debug3: Ignored env LOGNAME debug3: Ignored env CVS_RSH debug3: Ignored env QTLIB debug3: Ignored env DBUS_SESSION_BUS_ADDRESS debug3: Ignored env XDG_DATA_DIRS debug3: Ignored env LESSOPEN debug3: Ignored env WINDOWPATH debug3: Ignored env DISPLAY debug3: Ignored env G_BROKEN_FILENAMES debug3: Ignored env XAUTHORITY debug3: Ignored env COLORTERM debug3: Ignored env _ debug2: channel 0: request shell confirm 0 debug2: fd 3 setting TCP_NODELAY debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug2: channel 0: rcvd adjust 131072 Last login: Mon Feb 2 17:48:31 2009 from 72.112.134.121 Linux gabo 2.6.9-023stab040.1 #1 Tue Jan 16 00:40:25 MSK 2007 i686 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. gabo:~# debug1: client_input_channel_open: ctype forwarded-tcpip rchan 2 win 131072 max 32768 debug1: client_request_forwarded_tcpip: listen localhost port 2222, originator 127.0.0.1 port 49302 debug2: fd 9 setting O_NONBLOCK debug2: fd 9 setting TCP_NODELAY debug3: fd 9 is O_NONBLOCK debug3: fd 9 is O_NONBLOCK debug1: channel 1: new [127.0.0.1] debug1: confirm forwarded-tcpip debug3: channel 1: waiting for connection debug1: channel 1: connected 2.) Debug output of the server, trying to connect to the client through the forewarded port: gabo:~# ssh -l ce -p 2222 127.0.0.1 -vvv OpenSSH_4.3p2 Debian-9, OpenSSL 0.9.8c 05 Sep 2006 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to 127.0.0.1 [127.0.0.1] port 2222. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3p2 Debian-9 debug1: match: OpenSSH_4.3p2 Debian-9 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_4.3p2 Debian-9 debug2: fd 3 setting O_NONBLOCK debug1: Miscellaneous failure No credentials cache found debug1: Miscellaneous failure No credentials cache found debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: 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@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx,zlib debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx,zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: 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@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@xxxxxxxxxxxxxx,aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@xxxxxxxxxxx,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx debug2: kex_parse_kexinit: none,zlib@xxxxxxxxxxx debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: mac_init: found hmac-md5 debug1: kex: server->client aes128-cbc hmac-md5 none debug2: mac_init: 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: 136/256 debug2: bits set: 519/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts debug3: check_host_in_hostfile: match line 2 debug1: Host '127.0.0.1' is known and matches the RSA host key. debug1: Found key in /root/.ssh/known_hosts:2 debug2: bits set: 504/1024 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: /root/.ssh/identity ((nil)) debug2: key: /root/.ssh/id_rsa ((nil)) debug2: key: /root/.ssh/id_dsa ((nil)) debug1: Authentications that can continue: publickey,password debug3: start over, passed a different list publickey,password debug3: preferred gssapi-keyex,gssapi-with-mic,gssapi,publickey,keyboard-interactive,password debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Trying private key: /root/.ssh/identity debug3: no such identity: /root/.ssh/identity debug1: Trying private key: /root/.ssh/id_rsa debug3: no such identity: /root/.ssh/id_rsa debug1: Trying private key: /root/.ssh/id_dsa debug3: no such identity: /root/.ssh/id_dsa debug2: we did not send a packet, disable method debug3: authmethod_lookup password debug3: remaining preferred: ,password debug3: authmethod_is_enabled password debug1: Next authentication method: password ce@xxxxxxxxx's password: debug3: packet_send2: adding 64 (len 51 padlen 13 extra_pad 64) debug2: we sent a password packet, wait for reply debug1: Authentications that can continue: publickey,password Permission denied, please try again. ce@xxxxxxxxx's password:
