generate-certs

#!/bin/bash

if [[ -z $SILENT ]]; then
  echo "----------------------------"
  echo "| GENERICSSL Cert Generator |"
  echo "----------------------------"
  echo
fi

export CA_KEY=${CA_KEY-"ca-key.pem"}
export CA_CERT=${CA_CERT-"ca.pem"}
export CA_SUBJECT=${CA_SUBJECT:-"test-ca"}
export CA_EXPIRE=${CA_EXPIRE:-"60"}

export SSL_CONFIG=${SSL_CONFIG:-"openssl.cnf"}
export SSL_KEY=${SSL_KEY:-"key.pem"}
export SSL_CSR=${SSL_CSR:-"key.csr"}
export SSL_CERT=${SSL_CERT:-"cert.pem"}
export SSL_SIZE=${SSL_SIZE:-"2048"}
export SSL_EXPIRE=${SSL_EXPIRE:-"60"}

export SSL_SUBJECT=${SSL_SUBJECT:-"example.com"}
export SSL_DNS=${SSL_DNS}
export SSL_IP=${SSL_IP}

export K8S_NAME=${K8S_NAME:-"genericssl"}
export K8S_NAMESPACE=${K8S_NAMESPACE:-"default"}
export K8S_SAVE_CA_KEY=${K8S_SAVE_CA_KEY}
export K8S_SAVE_CA_CRT=${K8S_SAVE_CA_CRT}
export K8S_SHOW_SECRET=${K8S_SHOW_SECRET}

export OUTPUT=${OUTPUT:-"yaml"}

[[ -z $SILENT ]] && echo "--> Certificate Authority"

if [[ -e ./${CA_KEY} ]]; then
  [[ -z $SILENT ]] && echo "====> Using existing CA Key ${CA_KEY}"
else
  [[ -z $SILENT ]] && echo "====> Generating new CA key ${CA_KEY}"
  openssl genrsa -out "${CA_KEY}" "${SSL_SIZE}" >/dev/null
fi

if [[ -e ./${CA_CERT} ]]; then
  [[ -z $SILENT ]] && echo "====> Using existing CA Certificate ${CA_CERT}"
else
  [[ -z $SILENT ]] && echo "====> Generating new CA Certificate ${CA_CERT}"
  openssl req -x509 -new -nodes -key "${CA_KEY}" -days "${CA_EXPIRE}" -out "${CA_CERT}" -subj "/CN=${CA_SUBJECT}" >/dev/null || exit 1
fi

echo "====> Generating new config file ${SSL_CONFIG}"
cat >"${SSL_CONFIG}" <<EOM
[req]
req_extensions = v3_req
distinguished_name = req_distinguished_name
[req_distinguished_name]
[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
extendedKeyUsage = clientAuth, serverAuth
EOM

if [[ -n ${SSL_DNS} || -n ${SSL_IP} ]]; then
  cat >>"${SSL_CONFIG}" <<EOM
subjectAltName = @alt_names
[alt_names]
EOM

  IFS=";"
  read -ra dns <<<"$SSL_DNS"
  dns+=("${SSL_SUBJECT}")
  for ((i = 0; i < ${#dns[@]}; i++)); do
    if [ -z "${dns[$i]}" ]; then
      continue
    fi
    echo DNS.$((i + 1)) = "${dns[$i]}" >>"${SSL_CONFIG}"
  done

  if [[ -n ${SSL_IP} ]]; then
    read -ra ip <<<"$SSL_IP"
    for ((i = 0; i < ${#ip[@]}; i++)); do
      if [ -z "${ip[$i]}" ]; then
        continue
      fi
      echo IP.$((i + 1)) = "${ip[$i]}" >>"${SSL_CONFIG}"
    done
  fi
fi

[[ -z $SILENT ]] && echo "====> Generating new SSL KEY ${SSL_KEY}"
openssl genrsa -out "${SSL_KEY}" "${SSL_SIZE}" >/dev/null || exit 1

[[ -z $SILENT ]] && echo "====> Generating new SSL CSR ${SSL_CSR}"
openssl req -new -key "${SSL_KEY}" -out "${SSL_CSR}" -subj "/CN=${SSL_SUBJECT}" -config "${SSL_CONFIG}" >/dev/null || exit 1

[[ -z $SILENT ]] && echo "====> Generating new SSL CERT ${SSL_CERT}"
openssl x509 -req -in "${SSL_CSR}" -CA "${CA_CERT}" -CAkey "${CA_KEY}" -CAcreateserial -out "${SSL_CERT}" \
  -days "${SSL_EXPIRE}" -extensions v3_req -extfile "${SSL_CONFIG}" >/dev/null || exit 1

# create k8s secret file
cat <<EOM >/certs/secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: ${K8S_NAME}
  namespace: ${K8S_NAMESPACE}
type: kubernetes.io/tls
data:
EOM
if [[ -n $K8S_SAVE_CA_KEY ]]; then
  echo -n "  ca.key: " >>/certs/secret.yaml
  cat "$CA_KEY" | base64 | tr '\n' ',' | sed 's/,//g' >>/certs/secret.yaml
  echo >>/certs/secret.yaml
fi
if [[ -n $K8S_SAVE_CA_CRT ]]; then
  echo -n "  ca.crt: " >>/certs/secret.yaml
  cat "$CA_CERT" | base64 | tr '\n' ',' | sed 's/,//g' >>/certs/secret.yaml
  echo >>/certs/secret.yaml
fi
echo -n "  tls.key: " >>/certs/secret.yaml
cat "$SSL_KEY" | base64 | tr '\n' ',' | sed 's/,//g' >>/certs/secret.yaml
echo >>/certs/secret.yaml
echo -n "  tls.crt: " >>/certs/secret.yaml
cat "$SSL_CERT" | base64 | tr '\n' ',' | sed 's/,//g' >>/certs/secret.yaml
echo >>/certs/secret.yaml

if [[ -z $SILENT ]]; then
  echo "====> Complete"
  echo "keys can be found in volume mapped to $(pwd)"
  echo

  if [[ ${OUTPUT} == "k8s" ]]; then
    echo "====> Output results as base64 k8s secrets"
    echo "---"
    cat /certs/secret.yaml

  else
    echo "====> Output results as YAML"
    echo "---"
    echo "ca_key: |"
    cat "$CA_KEY" | sed 's/^/  /'
    echo
    echo "ca_crt: |"
    cat "$CA_CERT" | sed 's/^/  /'
    echo
    echo "ssl_key: |"
    cat "$SSL_KEY" | sed 's/^/  /'
    echo
    echo "ssl_csr: |"
    cat "$SSL_CSR" | sed 's/^/  /'
    echo
    echo "ssl_crt: |"
    cat "$SSL_CERT" | sed 's/^/  /'
    echo
  fi
fi