Summarize SSH Authorized Key Types

You need to count SSH key algorithms used in authorized_keys files.

Command

find home -path '*/.ssh/authorized_keys' -exec awk '{print $1}' {} + | sort | uniq -c | sort -nr

Before you run this

System impact: Read-only. Output may expose users, paths, tokens, keys, IPs, process arguments, or log details.

When not to use it: Do not delete RSA keys solely because they appear here; confirm policy, fingerprint, owner, and compatibility first.

Expected output

A count-sorted list of authorized SSH key types.

System impact

Read-only, sensitive output. Nothing changes. The command reads authorized_keys files and counts the first field, which is the key type.

Recovery / rollback: no state is changed.

When to use it

Use during SSH access reviews when you need to spot legacy key types before planning cleanup.

When not to use it

Do not delete RSA keys solely because they appear here; confirm policy, fingerprint, owner, and compatibility first.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ find home -path '*/ssh-keys/authorized_keys' -exec awk '{print FILENAME, $1}' {} +

home/deploy/ssh-keys/authorized_keys ssh-ed25519
home/bob/ssh-keys/authorized_keys ssh-rsa
home/alice/ssh-keys/authorized_keys ssh-ed25519
home/alice/ssh-keys/authorized_keys ssh-rsa

$ find home -path '*/ssh-keys/authorized_keys' -exec awk '{print $1}' {} + | sort | uniq -c | sort -nr

      2 ssh-rsa
      2 ssh-ed25519

View commands shown

These are the commands shown in the sanitized transcript.