Merge pull request #59 from erdgeist/master

when using printf, we do not need inline expansion of variables

letsencrypt.sh

@@ -130,7 +130,7 @@ init_system() {
   pubExponent64="$(openssl rsa -in "${PRIVATE_KEY}" -noout -text | grep publicExponent | grep -oE "0x[a-f0-9]+" | cut -d'x' -f2 | hex2bin | urlbase64)"
   pubMod64="$(openssl rsa -in "${PRIVATE_KEY}" -noout -modulus | cut -d'=' -f2 | hex2bin | urlbase64)"
 
-  thumbprint="$(printf '%s' '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | openssl sha -sha256 -binary | urlbase64)"
+  thumbprint="$(printf '{"e":"%s","kty":"RSA","n":"%s"}' "${pubExponent64}" "${pubMod64}" | openssl sha -sha256 -binary | urlbase64)"
 
   # If we generated a new private key in the step above we have to register it with the acme-server
   if [[ "${register}" = "1" ]]; then