I use ~/.ssh/authorized_keys to allow password-less SSH connection between computers. They worked fine under macOS Catalina, but since I upgraded to macOS Big Sur they no longer work. I can log in to the other macOS all right, but I'm always asked for a password. It looks as if the server ignores my
I tried recreating the keys with
ssh-keygen, removed the old
authorized_keys file and created a new one with
ssh-copy-id. Permissions seem fine:
8 -rw-r--r-- 1 xxx staff 2,1K 6 oct 17:20 authorized_keys 8 -rw------- 1 xxx staff 1,8K 9 oct 17:02 id_rsa 8 -rw-r--r-- 1 xxx staff 401B 9 oct 17:02 id_rsa.pub
I suspect something has changed in
/etc/sshd_config, but I can't figure out what.
The problem exists only when I try to ssh from macOS to macOS. From macOS to linux/ubuntu still works as expected (no password prompt).
Some interesting values from
debug1: Authentications that can continue: publickey,password,keyboard-interactive debug3: start over, passed a different list publickey,password,keyboard-interactive debug3: preferred publickey,keyboard-interactive,password debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey [...] debug2: we sent a publickey packet, wait for reply [...] debug2: we did not send a packet, disable method debug3: authmethod_lookup keyboard-interactive debug3: remaining preferred: password debug3: authmethod_is_enabled keyboard-interactive debug1: Next authentication method: keyboard-interactive debug2: userauth_kbdint debug3: send packet: type 50 debug2: we sent a keyboard-interactive packet, wait for reply debug3: receive packet: type 60 debug2: input_userauth_info_req debug2: input_userauth_info_req: num_prompts 1
When I log in from macOS to Linux/Ubuntu, I see a line:
Server accepts key: /path/to/id_rsa RSA [...]
The line is missing when I try to log in from macOS to another macOS machine.
I also tried different algorithms:
$ ssh-keygen -t dsa $ ssh-keygen -t ed25519
None of them worked. Does anybody have the same problem?