Tool to show cert, key or CSR information for a file or site

show

#!/bin/bash

if [ -z "$1" ];then
  echo "Showing certificate from clipboard"
  FILENAME=$(mktemp)
  trap "{ rm -f $FILENAME; }" EXIT
  xclip -o > $FILENAME
elif [ -e "$1" ]; then
  echo "Showing certificate file $1"
  FILENAME="$1"
elif [ "${1:0:5}" = "https" ]; then
  echo "Showing certificate for URL $1"
  curl --insecure -v $1 2>&1 | awk 'BEGIN { cert=0 } /^\* SSL connection/ { cert=1 } /^\*/ { if (cert) print }'
else
  echo "Showing certificate for domain name $1"
  echo -n | openssl s_client -connect $1:443 | openssl x509 -text
fi

if [ -n "$FILENAME" ]; then
  if grep -- ' PRIVATE KEY-' "$FILENAME" >/dev/null; then
    action=rsa
  elif grep -- '-BEGIN CERTIFICATE REQUEST-' "$FILENAME" >/dev/null; then
    action=req
  elif grep -- '-BEGIN CERTIFICATE-' "$FILENAME" >/dev/null; then
    action=x509
  elif grep -- '-BEGIN TRUSTED CERTIFICATE-' "$FILENAME" >/dev/null; then
    action=x509
  else
    action=unknown
  fi
  if [ "$action" = "unknown" ]; then
    echo "Couldn't detect the file type of $FILENAME"
    exit 1
  fi
  echo -n | openssl $action -in "$FILENAME" -noout -text
fi

See also https://github.com/mozilla-it/cert-tools/blob/master/ssl-inspect