list tls ciphers supported by a host

tls-ciphers.sh

#!/bin/bash

# Check if the host argument is provided
if [ -z "$1" ]; then
  echo "Usage: $0 host"
  exit 1
fi

# Get the host name
host=$1

# Get the list of all ciphers supported by openssl
ciphers=$(openssl ciphers 'ALL:eNULL')

# Initialize two arrays to store the supported and unsupported ciphers
supported=()
unsupported=()

# Loop through each cipher
for cipher in ${ciphers//:/ }; do
  # Try to connect to the host using the cipher
  result=$(echo -n | openssl s_client -cipher "$cipher" -connect $host:443 2>&1)
  # Check if the connection was successful
  if [[ "$result" =~ "Cipher is ${cipher}" ]]; then
    # Add the cipher to the supported array
    supported+=("$cipher")
  else
    # Add the cipher to the unsupported array
    unsupported+=("$cipher")
  fi
done

# Print the supported ciphers with a header
printf "\nSupported ciphers:\n"
printf "%s\n" "${supported[@]}"

# Print the unsupported ciphers with a header
printf "\nUnsupported ciphers:\n"
printf "%s\n" "${unsupported[@]}"