openssh hangs at "rekey after 134217728 blocks"
First up, I have searched around for a full day now and although there are similar problems around, I can't find anyone having this exact problem.
My hackintosh running 10.12.3 has OpenSSH installed via homebrew. It hangs at the exact same "rekey" line no matter which server I am connecting to, and I have no idea why.
(note: the expected result from the below should end with
Permission Denied (publickey).
because I haven't installed the cert, instead I am only using [email protected] to test. But it doesn't even make it that far, and that is the problem. My home server box running ubuntu yields the same hang point.)
➜ ~ ssh -vvv -T [email protected]
OpenSSH_7.5p1, OpenSSL 1.0.2k 26 Jan 2017
debug1: Reading configuration data /usr/local/etc/ssh/ssh_config
debug2: resolving "github.com" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to github.com [192.30.255.112] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Volumes/StorageRAID/ajlowndes/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.5
debug1: Remote protocol version 2.0, remote software version libssh-0.7.0
debug1: no match: libssh-0.7.0
debug2: fd 5 setting O_NONBLOCK
debug1: Authenticating to github.com:22 as 'git'
debug3: hostkeys_foreach: reading file "/Volumes/StorageRAID/ajlowndes/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Volumes/StorageRAID/ajlowndes/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from github.com
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],rsa-sha2-512,rsa-sha2-256,ssh-rsa,[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: host key algorithms: ssh-dss,ssh-rsa
debug2: ciphers ctos: [email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc
debug2: ciphers stoc: [email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc
debug2: MACs ctos: hmac-sha1,hmac-sha2-256,hmac-sha2-512
debug2: MACs stoc: hmac-sha1,hmac-sha2-256,hmac-sha2-512
debug2: compression ctos: none,zlib,[email protected]
debug2: compression stoc: none,zlib,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ssh-rsa SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8
debug3: hostkeys_foreach: reading file "/Volumes/StorageRAID/ajlowndes/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Volumes/StorageRAID/ajlowndes/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from github.com
debug3: hostkeys_foreach: reading file "/Volumes/StorageRAID/ajlowndes/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Volumes/StorageRAID/ajlowndes/.ssh/known_hosts:11
debug3: load_hostkeys: loaded 1 keys from 192.30.255.112
debug1: Host 'github.com' is known and matches the RSA host key.
debug1: Found key in /Volumes/StorageRAID/ajlowndes/.ssh/known_hosts:2
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
I also tried a previous version of ssh:
➜ ~ /usr/local/Cellar/openssh/7.4p1/bin/ssh -vvv -T [email protected]
with exactly the same result.
And I tried the macOS native version like so:
➜ ~ /usr/bin/ssh -vvv -T [email protected]
OpenSSH_7.3p1, LibreSSL 2.4.1
... {same stuff} ...
Warning: Permanently added the RSA host key for IP address '192.30.255.113' to the list of known hosts.
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
I note that the last three lines are in a different order, otherwise there seems to be no difference.
Other computers (e.g. MacBook Air) with mac's native ssh have no problem. It is only the hackintosh. Any ideas where I can troubleshoot next?
Thanks in advance.
Note: I can ssh TO the hackintosh no problem, just not from it.
The issue is ssh is waiting for a connection to your ssh-agent. You can test this by running SSH_AUTH_SOCK= ssh [email protected].
If this is indeed the issue (as it was for me), then you probably have multiple LaunchAgents that are listening on the socket at SSH_AUTH_SOCK and one of them is doing the wrong thing. For example, I had one from MacPorts that was trying to run /opt/local/bin/ssh-agent -l but that ssh-agent did not exist any longer.
You should have one LaunchAgent for ssh-agent in /System/Library/LaunchAgents/com.openssh.ssh-agent.plist but you may have others in /Library/LaunchAgents or ~/Library/LaunchAgents. If so, unload the ssh-agent LaunchAgents using launchctl unload or simply delete them and logout and back in (or maybe restart, I'm not sure if a logout is sufficient). Hopefully, that should fix your problem.