Version 3.6 and later

The embedded OpenSSH in Core Shell/ Tunnel version 3.6.x was updated to version 8.8, you might be unable to connect servers with older SSH implementations.

OpenSSH 8.8 disables RSA signatures using the SHA-1 hash algorithm by default. Though there is a stopgap measure, we recommend you upgrade your SSH server or reconfigured with another key type (such as ECDSA or Ed25519).

To fix connection problems, first check your connection log.

Error: no matching host key type found

[TIMESTAMP] Unable to negotiate with [HOST] port [PORT]: no matching host key type found. Their offer: ssh-rsa,ssh-dss

Set HostkeyAlgorithms to +ssh-rsa in Advanced options in Settings of the profile.

Error: Permission denied (publickey).

[TIMESTAMP] debug1: Next authentication method: publickey
[TIMESTAMP] debug1: Offering public key: /Users/username/Library/Group Containers/ RSA SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx explicit
[TIMESTAMP] debug1: send_pubkey_test: no mutual signature algorithm
[TIMESTAMP] debug2: we did not send a packet, disable method
[TIMESTAMP] debug1: No more authentication methods to try.
[TIMESTAMP] [HOST]: Permission denied (publickey).

Set PubkeyAcceptedAlgorithms to +ssh-rsa in Advanced options in Settings of the profile.

PubkeyAcceptedKeyTypes and HostbasedKeyTypes directives are disappeared

In OpenSSH 8.5 and later, PubkeyAcceptedKeyTypes keyword was renamed to PubkeyAcceptedAlgorithms, similarly, HostbasedKeyTypes was renamed to HostbasedAcceptedAlgorithms.