Recently used SSH logins

sshlastaccess.sh

#!/bin/bash

# Array to store unique public key signatures
declare -A public_keys

# Loop through auth.log files
for file in /var/log/auth.log*; do
    # Check if file exists and is readable
    if [ -r "$file" ]; then
        # Extract public key signatures, timestamps, users, and source IP addresses
        while read -r line; do
            if [[ $line =~ "publickey" && $line =~ "Accepted" ]]; then
                signature=$(echo "$line" | awk '{print $NF}')
                timestamp=$(echo "$line" | awk '{print $1, $2, $3}')
                user=$(echo "$line" | awk '{print $9}')
                source_ip=$(echo "$line" | awk '{print $11}')
                public_keys["$signature"]="$timestamp, User: $user, From: $source_ip"
            fi
        done < "$file"
    fi
done

# Output unique public key signatures, last usage timestamps, users, and source IP addresses
for key in "${!public_keys[@]}"; do
    echo "Public Key Signature: $key"
    echo "Last Used: ${public_keys[$key]}"
    echo "---------------------------------------"
done