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Created attachment 1585180[details]
reproducer
Description of problem: The latest version 0.8.91 in RHEL 8.1 (and now also Fedora Rawhide) breaks known hosts handling. Hosts are now considered unknown even when
Version-Release number of selected component (if applicable):
libssh-0.8.91-0.1.el8
How reproducible: Always
Steps to Reproduce:
1. Generate a local ./knownhosts file with
ssh -o UserKnownHostsFile=./knownhosts 127.0.0.1
No need to log in, just confirm the host key.
2. Build and run the attached reproducer, which exercises ssh_session_has_known_hosts_entry:
gcc -Wall -o client-knownhost client-knownhost.c -lssh && ./client-knownhost
Actual results:
Validate that with libssh up to 0.8.7, the host is known, i. e. that you did the ./knownhosts
[2019/06/27 15:27:32.815499, 2] ssh_connect: libssh 0.8.7 (c) 2003-2018 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread
[2019/06/27 15:27:32.815815, 2] ssh_socket_connect: Nonblocking connection socket: 3
[2019/06/27 15:27:32.815883, 2] ssh_connect: Socket connecting, now waiting for the callbacks to work
[2019/06/27 15:27:32.815931, 1] socket_callback_connected: Socket connection callback: 1 (0)
[2019/06/27 15:27:32.829473, 1] ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_8.0
[2019/06/27 15:27:32.829528, 1] ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_8.0
[2019/06/27 15:27:32.829554, 1] ssh_analyze_banner: We are talking to an OpenSSH client version: 8.0 (80000)
[2019/06/27 15:27:32.829747, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory
[2019/06/27 15:27:32.832632, 2] ssh_kex_select_methods: Negotiated curve25519-sha256,ecdsa-sha2-nistp256,aes256-ctr,aes256-ctr,hmac-sha2-256,hmac-sha2-256,none,none,,
[2019/06/27 15:27:32.844292, 2] ssh_packet_dh_reply: Received SSH_KEXDH_REPLY
[2019/06/27 15:27:32.848752, 2] ssh_client_curve25519_reply: SSH_MSG_NEWKEYS sent
[2019/06/27 15:27:32.848811, 2] ssh_packet_newkeys: Received SSH_MSG_NEWKEYS
[2019/06/27 15:27:32.849191, 2] ssh_packet_newkeys: Signature verified and valid
[2019/06/27 15:27:32.849289, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory
host known: 1
with libssh 0.8.91, it is not known:
[2019/06/27 15:29:50.895746, 1] ssh_config_parse_line: line 3: Unsupported Match keyword 'final', skipping
[2019/06/27 15:29:50.895880, 2] ssh_config_parse_line: Unapplicable option: ForwardX11Trusted, line: 12
[2019/06/27 15:29:50.895957, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 15
[2019/06/27 15:29:50.895997, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 16
[2019/06/27 15:29:50.896033, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 17
[2019/06/27 15:29:50.896056, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 18
[2019/06/27 15:29:50.896097, 2] ssh_connect: libssh 0.8.91 (c) 2003-2019 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread
[2019/06/27 15:29:50.896312, 2] ssh_socket_connect: Nonblocking connection socket: 3
[2019/06/27 15:29:50.896379, 2] ssh_connect: Socket connecting, now waiting for the callbacks to work
[2019/06/27 15:29:50.896430, 1] socket_callback_connected: Socket connection callback: 1 (0)
[2019/06/27 15:29:50.908453, 2] ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_8.0
[2019/06/27 15:29:50.908497, 2] ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_8.0
[2019/06/27 15:29:50.908517, 2] ssh_analyze_banner: We are talking to an OpenSSH client version: 8.0 (80000)
[2019/06/27 15:29:50.908684, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory
[2019/06/27 15:29:50.910906, 2] ssh_kex_select_methods: Negotiated curve25519-sha256,ecdsa-sha2-nistp256,aes256-gcm,aes256-gcm,hmac-sha2-256-etm,hmac-sha2-256-etm,none,none,,
[2019/06/27 15:29:50.924347, 2] ssh_init_rekey_state: Set rekey after 4294967296 blocks
[2019/06/27 15:29:50.924399, 2] ssh_init_rekey_state: Set rekey after 4294967296 blocks
[2019/06/27 15:29:50.924417, 2] ssh_packet_client_curve25519_reply: SSH_MSG_NEWKEYS sent
[2019/06/27 15:29:50.924433, 2] ssh_packet_newkeys: Received SSH_MSG_NEWKEYS
[2019/06/27 15:29:50.924743, 2] ssh_packet_newkeys: Signature verified and valid
host known: -1
(The /builddir is because I'm running this in mock).
-1 means SSH_KNOWN_HOSTS_NOT_FOUND. This happens also with specifying an absolute instead of relative path, and also with SSH_OPTIONS_KNOWNHOSTS instead of _GLOBAL_KNOWNHOSTS.
Expected results: Host is known with 0.8.91
Additional info:
Thanks Anderson! This affects package builds, where my .spec can't just create an /etc/ssh/ssh_known_hosts. But fixing this in the next days is certainly fast enough, we still have some time in RHEL 8.1 to land stuff. Thanks!
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2019:3657
Created attachment 1585180 [details] reproducer Description of problem: The latest version 0.8.91 in RHEL 8.1 (and now also Fedora Rawhide) breaks known hosts handling. Hosts are now considered unknown even when Version-Release number of selected component (if applicable): libssh-0.8.91-0.1.el8 How reproducible: Always Steps to Reproduce: 1. Generate a local ./knownhosts file with ssh -o UserKnownHostsFile=./knownhosts 127.0.0.1 No need to log in, just confirm the host key. 2. Build and run the attached reproducer, which exercises ssh_session_has_known_hosts_entry: gcc -Wall -o client-knownhost client-knownhost.c -lssh && ./client-knownhost Actual results: Validate that with libssh up to 0.8.7, the host is known, i. e. that you did the ./knownhosts [2019/06/27 15:27:32.815499, 2] ssh_connect: libssh 0.8.7 (c) 2003-2018 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread [2019/06/27 15:27:32.815815, 2] ssh_socket_connect: Nonblocking connection socket: 3 [2019/06/27 15:27:32.815883, 2] ssh_connect: Socket connecting, now waiting for the callbacks to work [2019/06/27 15:27:32.815931, 1] socket_callback_connected: Socket connection callback: 1 (0) [2019/06/27 15:27:32.829473, 1] ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_8.0 [2019/06/27 15:27:32.829528, 1] ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_8.0 [2019/06/27 15:27:32.829554, 1] ssh_analyze_banner: We are talking to an OpenSSH client version: 8.0 (80000) [2019/06/27 15:27:32.829747, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory [2019/06/27 15:27:32.832632, 2] ssh_kex_select_methods: Negotiated curve25519-sha256,ecdsa-sha2-nistp256,aes256-ctr,aes256-ctr,hmac-sha2-256,hmac-sha2-256,none,none,, [2019/06/27 15:27:32.844292, 2] ssh_packet_dh_reply: Received SSH_KEXDH_REPLY [2019/06/27 15:27:32.848752, 2] ssh_client_curve25519_reply: SSH_MSG_NEWKEYS sent [2019/06/27 15:27:32.848811, 2] ssh_packet_newkeys: Received SSH_MSG_NEWKEYS [2019/06/27 15:27:32.849191, 2] ssh_packet_newkeys: Signature verified and valid [2019/06/27 15:27:32.849289, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory host known: 1 with libssh 0.8.91, it is not known: [2019/06/27 15:29:50.895746, 1] ssh_config_parse_line: line 3: Unsupported Match keyword 'final', skipping [2019/06/27 15:29:50.895880, 2] ssh_config_parse_line: Unapplicable option: ForwardX11Trusted, line: 12 [2019/06/27 15:29:50.895957, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 15 [2019/06/27 15:29:50.895997, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 16 [2019/06/27 15:29:50.896033, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 17 [2019/06/27 15:29:50.896056, 2] ssh_config_parse_line: Unapplicable option: SendEnv, line: 18 [2019/06/27 15:29:50.896097, 2] ssh_connect: libssh 0.8.91 (c) 2003-2019 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread [2019/06/27 15:29:50.896312, 2] ssh_socket_connect: Nonblocking connection socket: 3 [2019/06/27 15:29:50.896379, 2] ssh_connect: Socket connecting, now waiting for the callbacks to work [2019/06/27 15:29:50.896430, 1] socket_callback_connected: Socket connection callback: 1 (0) [2019/06/27 15:29:50.908453, 2] ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_8.0 [2019/06/27 15:29:50.908497, 2] ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_8.0 [2019/06/27 15:29:50.908517, 2] ssh_analyze_banner: We are talking to an OpenSSH client version: 8.0 (80000) [2019/06/27 15:29:50.908684, 1] ssh_known_hosts_read_entries: Failed to open the known_hosts file '/builddir/.ssh/known_hosts': No such file or directory [2019/06/27 15:29:50.910906, 2] ssh_kex_select_methods: Negotiated curve25519-sha256,ecdsa-sha2-nistp256,aes256-gcm,aes256-gcm,hmac-sha2-256-etm,hmac-sha2-256-etm,none,none,, [2019/06/27 15:29:50.924347, 2] ssh_init_rekey_state: Set rekey after 4294967296 blocks [2019/06/27 15:29:50.924399, 2] ssh_init_rekey_state: Set rekey after 4294967296 blocks [2019/06/27 15:29:50.924417, 2] ssh_packet_client_curve25519_reply: SSH_MSG_NEWKEYS sent [2019/06/27 15:29:50.924433, 2] ssh_packet_newkeys: Received SSH_MSG_NEWKEYS [2019/06/27 15:29:50.924743, 2] ssh_packet_newkeys: Signature verified and valid host known: -1 (The /builddir is because I'm running this in mock). -1 means SSH_KNOWN_HOSTS_NOT_FOUND. This happens also with specifying an absolute instead of relative path, and also with SSH_OPTIONS_KNOWNHOSTS instead of _GLOBAL_KNOWNHOSTS. Expected results: Host is known with 0.8.91 Additional info: