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ssh2.sh test failed with OpenSSH 8.8p1 #630

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icebluey opened this issue Oct 5, 2021 · 15 comments
Closed

ssh2.sh test failed with OpenSSH 8.8p1 #630

icebluey opened this issue Oct 5, 2021 · 15 comments

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@icebluey
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icebluey commented Oct 5, 2021 •
edited

libssh2 version: 1.9.0 and 1.10.0

[root@localhost]# make check
...
PASS: simple
PASS: mansyntax.sh
FAIL: ssh2.sh
============================================================================
Testsuite summary for libssh2 -
============================================================================
# TOTAL: 3
# PASS:  2
# SKIP:  0
# XFAIL: 0
# FAIL:  1
# XPASS: 0
# ERROR: 0
============================================================================
See tests/test-suite.log
Please report to libssh2-devel@cool.haxx.se
============================================================================



[root@localhost]# cat tests/test-suite.log
=====================================
   libssh2 -: tests/test-suite.log
=====================================

# TOTAL: 3
# PASS:  2
# SKIP:  0
# XFAIL: 0
# FAIL:  1
# XPASS: 0
# ERROR: 0

.. contents:: :depth: 2

FAIL: ssh2.sh
=============

command-line line 0: Deprecated option UsePrivilegeSeparation
command-line line 0: Deprecated option UsePrivilegeSeparation
Failure establishing SSH session
FAIL ssh2.sh (exit status: 1)

[root@localhost]# ssh -V
OpenSSH_8.8p1, OpenSSL 1.1.1l  24 Aug 2021
@willco007
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Could you add the error output to this report or the ssh error logs?

@icebluey
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icebluey commented Oct 5, 2021

Error output in logfile:

sshd[906]: Server listening on 0.0.0.0 port 4764.
sshd[906]: Server listening on :: port 4764.
sshd[906]: Received signal 15; terminating.
sshd[937]: Unable to negotiate with 127.0.0.1 port 18162: no matching host key type found. Their offer: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-ed25519,ssh-rsa,ssh-dss [preauth]

@kanavin
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kanavin commented Oct 19, 2021 •
edited

Seeing this in local testing as well.

root@qemux86-64:/usr/lib/libssh2/ptest/tests# DEBUG=1 ./ssh2.sh 
command-line line 0: Deprecated option UsePrivilegeSeparation
debug2: load_server_config: filename /dev/null
debug2: load_server_config: done config len = 1
debug2: parse_server_config_depth: config /dev/null len 1
debug1: sshd version OpenSSH_8.8, OpenSSL 3.0.0 7 sep 2021
debug1: private host key #0: ssh-rsa SHA256:vYc4H82Dsul0alhutVzAnUmjUibvKXoHWY022QWJbxs
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-f'
debug1: rexec_argv[2]='/dev/null'
debug1: rexec_argv[3]='-h'
debug1: rexec_argv[4]='/usr/lib/libssh2/ptest/tests/etc/host'
debug1: rexec_argv[5]='-o'
debug1: rexec_argv[6]='Port 4711'
debug1: rexec_argv[7]='-o'
debug1: rexec_argv[8]='Protocol 2'
debug1: rexec_argv[9]='-o'
debug1: rexec_argv[10]='AuthorizedKeysFile /usr/lib/libssh2/ptest/tests/etc/user.pub'
debug1: rexec_argv[11]='-o'
debug1: rexec_argv[12]='UsePrivilegeSeparation no'
debug1: rexec_argv[13]='-o'
debug1: rexec_argv[14]='StrictModes no'
debug1: rexec_argv[15]='-D'
debug1: rexec_argv[16]='-d'
debug1: rexec_argv[17]='-d'
debug1: Set /proc/self/oom_score_adj from 0 to -1000
debug2: fd 3 setting O_NONBLOCK
debug1: Bind to port 4711 on 0.0.0.0.
Server listening on 0.0.0.0 port 4711.
debug2: fd 4 setting O_NONBLOCK
debug1: Bind to port 4711 on ::.
Server listening on :: port 4711.
debug1: Server will not fork when running in debugging mode.
debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8
command-line line 0: Deprecated option UsePrivilegeSeparation
debug2: parse_server_config_depth: config rexec len 1
debug1: sshd version OpenSSH_8.8, OpenSSL 3.0.0 7 sep 2021
debug1: private host key #0: ssh-rsa SHA256:vYc4H82Dsul0alhutVzAnUmjUibvKXoHWY022QWJbxs
debug1: inetd sockets after dupping: 3, 3
Connection from 127.0.0.1 port 57322 on 127.0.0.1 port 4711 rdomain ""
debug1: Local version string SSH-2.0-OpenSSH_8.8
debug1: Remote protocol version 2.0, remote software version libssh2_1.10.0
debug1: compat_banner: no match: libssh2_1.10.0
debug2: fd 3 setting O_NONBLOCK
debug2: Network child is on pid 2438
debug1: permanently_set_uid: 998/998 [preauth]
debug1: list_hostkey_types: rsa-sha2-512,rsa-sha2-256 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
Failure establishing SSH session
debug1: SSH2_MSG_KEXINIT received [preauth]
debug2: local server KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-]
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256 [preauth]
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com [preauth]
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com [preauth]
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,h]
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,h]
debug2: compression ctos: none,zlib@openssh.com [preauth]
debug2: compression stoc: none,zlib@openssh.com [preauth]
debug2: languages ctos:  [preauth]
debug2: languages stoc:  [preauth]
debug2: first_kex_follows 0  [preauth]
debug2: reserved 0  [preauth]
debug2: peer client KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-]
debug2: host key algorithms: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.co]
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
debug2: MACs ctos: hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
debug2: MACs stoc: hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
debug2: compression ctos: none [preauth]
debug2: compression stoc: none [preauth]
debug2: languages ctos:  [preauth]
debug2: languages stoc:  [preauth]
debug2: first_kex_follows 0  [preauth]
debug2: reserved 0  [preauth]
debug1: kex: algorithm: curve25519-sha256 [preauth]
debug1: kex: host key algorithm: (no match) [preauth]
Unable to negotiate with 127.0.0.1 port 57322: no matching host key type found. Their offer: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp]
debug1: do_cleanup [preauth]
debug1: monitor_read_log: child log fd closed
debug1: do_cleanup
debug1: Killing privsep child 2438

@willco007
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Which test is failing? These logs show different types of failures.

@kanavin
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kanavin commented Oct 19, 2021

ssh2.sh is the failing test in all of them, I'm just running it manually in a standalone target install. And the issue seems similar too:

Unable to negotiate with 127.0.0.1 port 57322: no matching host key type found. Their offer: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp]

@willco007
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We are only offering curve25519-sha256 instead of matching what the server is offering in the key exchange. I'm not sure why/how this would have changed. I don't have Docker set up on this machine at the moment, but it should be possible to see what's happening by looking at kex_agree_instr.

@icebluey icebluey changed the title make check failed with OpenSSH 8.8p1 ssh2.sh test failed with OpenSSH 8.8p1 Oct 25, 2021
@willco007
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OK, in the first report the server is only offering rsa-sha2-512,rsa-sha2-256 host keys which aren't supported yet. In 8.8 OpenSSH disabled sha1 rsa-sha keys out of the box which is why this is all of a sudden failing. There is a PR to add support here #626. Could one of you try that PR to make sure it fixes this issue before I land it? Thanks!

@kanavin
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kanavin commented Oct 26, 2021

Some progress but not there yet.

root@qemux86-64:/usr/lib/libssh2/ptest/tests# DEBUG=1 ./ssh2.sh 
command-line line 0: Deprecated option UsePrivilegeSeparation
debug2: load_server_config: filename /dev/null
debug2: load_server_config: done config len = 1
debug2: parse_server_config_depth: config /dev/null len 1
debug1: sshd version OpenSSH_8.8, OpenSSL 3.0.0 7 sep 2021
debug1: private host key #0: ssh-rsa SHA256:vYc4H82Dsul0alhutVzAnUmjUibvKXoHWY022QWJbxs
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-f'
debug1: rexec_argv[2]='/dev/null'
debug1: rexec_argv[3]='-h'
debug1: rexec_argv[4]='/usr/lib/libssh2/ptest/tests/etc/host'
debug1: rexec_argv[5]='-o'
debug1: rexec_argv[6]='Port 4711'
debug1: rexec_argv[7]='-o'
debug1: rexec_argv[8]='Protocol 2'
debug1: rexec_argv[9]='-o'
debug1: rexec_argv[10]='AuthorizedKeysFile /usr/lib/libssh2/ptest/tests/etc/user.pub'
debug1: rexec_argv[11]='-o'
debug1: rexec_argv[12]='UsePrivilegeSeparation no'
debug1: rexec_argv[13]='-o'
debug1: rexec_argv[14]='StrictModes no'
debug1: rexec_argv[15]='-D'
debug1: rexec_argv[16]='-d'
debug1: rexec_argv[17]='-d'
debug1: Set /proc/self/oom_score_adj from 0 to -1000
debug2: fd 3 setting O_NONBLOCK
debug1: Bind to port 4711 on 0.0.0.0.
Server listening on 0.0.0.0 port 4711.
debug2: fd 4 setting O_NONBLOCK
debug1: Bind to port 4711 on ::.
Server listening on :: port 4711.
debug1: Server will not fork when running in debugging mode.
debug1: rexec start in 5 out 5 newsock 5 pipe -1 sock 8
command-line line 0: Deprecated option UsePrivilegeSeparation
debug2: parse_server_config_depth: config rexec len 1
debug1: sshd version OpenSSH_8.8, OpenSSL 3.0.0 7 sep 2021
debug1: private host key #0: ssh-rsa SHA256:vYc4H82Dsul0alhutVzAnUmjUibvKXoHWY022QWJbxs
debug1: inetd sockets after dupping: 3, 3
Connection from 127.0.0.1 port 59872 on 127.0.0.1 port 4711 rdomain ""
debug1: Local version string SSH-2.0-OpenSSH_8.8
debug1: Remote protocol version 2.0, remote software version libssh2_1.9.0_DEV
debug1: compat_banner: no match: libssh2_1.9.0_DEV
debug2: fd 3 setting O_NONBLOCK
debug2: Network child is on pid 2331
debug1: permanently_set_uid: 998/998 [preauth]
debug1: list_hostkey_types: rsa-sha2-512,rsa-sha2-256 [preauth]
debug1: SSH2_MSG_KEXINIT sent [preauth]
debug1: SSH2_MSG_KEXINIT received [preauth]
debug2: local server KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-]
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256 [preauth]
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com [preauth]
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com [preauth]
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,h]
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,h]
debug2: compression ctos: none,zlib@openssh.com [preauth]
debug2: compression stoc: none,zlib@openssh.com [preauth]
debug2: languages ctos:  [preauth]
debug2: languages stoc:  [preauth]
debug2: first_kex_follows 0  [preauth]
debug2: reserved 0  [preauth]
debug2: peer client KEXINIT proposal [preauth]
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-]
debug2: host key algorithms: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.co]
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-cbc,aes128-cbc,blowfish-cbc,arcfour128,arcfour,cast128-cbc,3des-cbc [preauth]
debug2: MACs ctos: hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
debug2: MACs stoc: hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-ripemd160@openssh.com [preauth]
debug2: compression ctos: none [preauth]
debug2: compression stoc: none [preauth]
debug2: languages ctos:  [preauth]
debug2: languages stoc:  [preauth]
debug2: first_kex_follows 0  [preauth]
debug2: reserved 0  [preauth]
debug1: kex: algorithm: curve25519-sha256 [preauth]
debug1: kex: host key algorithm: rsa-sha2-512 [preauth]
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha2-256 compression: none [preauth]
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha2-256 compression: none [preauth]
debug1: expecting SSH2_MSG_KEX_ECDH_INIT [preauth]
debug1: SSH2_MSG_KEX_ECDH_INIT received [preauth]
debug2: monitor_read: 6 used once, disabling now
debug2: set_newkeys: mode 1 [preauth]
debug1: rekey out after 4294967296 blocks [preauth]
debug1: SSH2_MSG_NEWKEYS sent [preauth]
debug1: expecting SSH2_MSG_NEWKEYS [preauth]
debug1: SSH2_MSG_NEWKEYS received [preauth]
debug2: set_newkeys: mode 0 [preauth]
debug1: rekey in after 4294967296 blocks [preauth]
debug1: KEX done [preauth]
Fingerprint: 86 AD B2 21 33 60 65 3D 9A 29 86 DE 22 99 DA 18 CC BA D3 AC 
debug1: userauth-request for user root service ssh-connection method none [preauth]
debug1: attempt 0 failures 0 [preauth]
debug2: parse_server_config_depth: config reprocess config len 1
debug2: monitor_read: 8 used once, disabling now
debug2: input_userauth_request: setting up authctxt for root [preauth]
debug2: input_userauth_request: try method none [preauth]
debug2: monitor_read: 4 used once, disabling now
Authentication methods: publickey,password,keyboard-interactive
debug1: userauth-request for user root service ssh-connection method publickey [preauth]
debug1: attempt 1 failures 0 [preauth]
debug2: input_userauth_request: try method publickey [preauth]
debug2: userauth_pubkey: valid user root querying public key ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAxIgBuZS39D4bFnWminE7svGQLdVKx1aWKnEYEa+XtNU4DKZ/pxUHg0zbEBya+IkX1yqQYWALoiOwI8XhdemLp8g03BX7o+DLSWisfiHpCDVGAuNqR]
userauth_pubkey: key type ssh-rsa not in PubkeyAcceptedAlgorithms [preauth]
debug2: userauth_pubkey: authenticated 0 pkalg ssh-rsa [preauth]
	Authentication by public key failed!
Received disconnect from 127.0.0.1 port 59872:11: Normal Shutdown [preauth]
Disconnected from authenticating user root 127.0.0.1 port 59872 [preauth]
debug1: do_cleanup [preauth]
debug1: monitor_read_log: child log fd closed
debug1: do_cleanup
debug1: Killing privsep child 2331

@willco007
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To fix this in the short term you can re-enable ssh-rsa by adding PubkeyAcceptedAlgorithms =+ rsa-sha to the sshd config file. I'm looking at what it takes to upgrade the RSA key to use a stronger algorithm since sha1 is now disabled by default.

@icebluey
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It's time to support ssh-ed25519 and ecdsa-sha2-nistp521 in host key algorithms right now.

@willco007
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@icebluey libssh2 supports both of them, the tests are just set up to use RSA keys. Which, in this case, is exposed a breaking change with OpenSSH 8.8 which libssh2 will need to support. See #536 which is ultimately why it's breaking.

@icebluey
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Is it possible to add ssh-ed25519 and ecdsa-sha2-nistp521 to the tests?
Then if RSA fails, one of these can pass.

@willco007
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Rebuilding from the latest changes in #626 should resolve this issue.

@willco007 willco007 mentioned this issue Nov 9, 2021
Closed
@AlexRamallo AlexRamallo mentioned this issue Dec 28, 2021
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@Zenju
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Zenju commented Feb 7, 2022

Rebuilding from the latest changes in #626 should resolve this issue.

For what it's worth, the latest official release libssh 1.10.0 is broken for OpenSSH_8.8p1 servers and newer (e.g. on openSUSE Tumbleweed) when trying to log in via key file (libssh2_userauth_publickey_frommemory), instead of user/password.
However these changes seem to fix the issue when testing today's master branch!

@willco007
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@Zenju Thanks for the confirmation! I'm going to close this as fixed with #626.

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@kanavin @willco007 @Zenju @icebluey