Bug#977971: openssh-client: ssh-keygen fails to create ed25519-sk

Package: openssh-client
Version: 1:8.4p1-2~bpo10+1
Severity: normal

Dear Maintainer,

I tried to create a ssh key pair with the command
ssh-keygen -t ed25519-sk

I got the following output:
Generating public/private ed25519-sk key pair.
You may need to touch your authenticator to authorize key generation.
Key enrollment failed: invalid format

No key was created.

So I tried again, this time with
ssh-keygen -t ecdsa-sk

I got the following output:
Generating public/private ecdsa-sk key pair.
You may need to touch your authenticator to authorize key generation.
Enter file in which to save the key (/home/iw/.ssh/id_ecdsa_sk): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/iw/.ssh/id_ecdsa_sk
Your public key has been saved in /home/iw/.ssh/id_ecdsa_sk.pub

As you can see, a key was created.

I tried the same on another machine running Debian. And on a machine
runnig Ubuntu 20.04. They showed the same behavior.

Regards,

Ingo

-- System Information:
Debian Release: 10.7
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.8.0-0.bpo.2-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages openssh-client depends on:
ii  adduser           3.118
ii  dpkg              1.19.7
ii  libc6             2.28-10
ii  libedit2          3.1-20181209-1
ii  libfido2-1        1.5.0-2~bpo10+1
ii  libgssapi-krb5-2  1.17-3+deb10u1
ii  libselinux1       2.8-1+b1
ii  libssl1.1         1.1.1d-0+deb10u4
ii  passwd            1:4.5-1.1
ii  zlib1g            1:1.2.11.dfsg-1

Versions of packages openssh-client recommends:
ii  xauth  1:1.0.10-1

Versions of packages openssh-client suggests:
pn  keychain                   <none>
ii  ksshaskpass [ssh-askpass]  4:5.14.5-1
pn  libpam-ssh                 <none>
pn  monkeysphere               <none>

-- no debconf information