umask 077 # paranoid umask, we're creating private keys
+anti_newline() {
+ tr -d '\n\r'
+}
urlbase64() {
- base64 -w 0 | sed -r 's/=*$//g' | tr '+/' '-_'
+ # urlbase64: base64 encoded string with '+' replaced with '-' and '/' replaced with '_'
+ openssl base64 -e | anti_newline | sed -r 's/=*$//g' | tr '+/' '-_'
}
hex2bin() {
+ # Store hex string from stdin
tmphex="$(cat)"
- # remove spaces
+ # Remove spaces
hex=''
for ((i=0; i<${#tmphex}; i+=1)); do
test "${tmphex:$i:1}" == " " || hex="${hex}${tmphex:$i:1}"
done
- # add leading zero
+ # Add leading zero
test $((${#hex} & 1)) == 0 || hex="0${hex}"
- # convert to escaped string
+ # Convert to escaped string
escapedhex=''
for ((i=0; i<${#hex}; i+=2)); do
escapedhex=$escapedhex\\x${hex:$i:2}
done
+ # Convert to binary data
printf "${escapedhex}"
}
}
signed_request() {
+ # Encode payload as urlbase64
payload64="$(printf '%s' "${2}" | urlbase64)"
- # -sSf: stay silent but report errors and exit with != 0 if they occur
- nonce="$(_request head "${CA}/directory" | grep Replay-Nonce: | awk -F ': ' '{print $2}' | tr -d '\n\r')"
+ # Retrieve nonce from acme-server
+ nonce="$(_request head "${CA}/directory" | grep Replay-Nonce: | awk -F ': ' '{print $2}' | anti_newline)"
+ # Build header with just our public key and algorithm information
header='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}}'
+ # Build another header which also contains the previously received nonce and encode it as urlbase64
protected='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}, "nonce": "'"${nonce}"'"}'
protected64="$(printf '%s' "${protected}" | urlbase64)"
+ # Sign header with nonce and our payload with our private key and encode signature as urlbase64
signed64="$(printf '%s' "${protected64}.${payload64}" | openssl dgst -sha256 -sign private_key.pem | urlbase64)"
+ # Send header + extended header + payload + signature to the acme-server
data='{"header": '"${header}"', "protected": "'"${protected64}"'", "payload": "'"${payload64}"'", "signature": "'"${signed64}"'"}'
_request post "${1}" "${data}"
domain="${1}"
altnames="${*}"
echo "Signing domain ${1} (${*})..."
- if [ ! -e "certs/${domain}" ]; then
- SAN=""
- for altname in $altnames; do
- SAN+="DNS:${altname}, "
- done
- SAN="$(printf '%s' "${SAN}" | sed 's/,\s*$//g')"
+ # If there is no existing certificate directory we need a new private key
+ if [ ! -e "certs/${domain}" ]; then
mkdir "certs/${domain}"
-
echo " + Generating private key..."
openssl genrsa -out "certs/${domain}/privkey.pem" 4096 2> /dev/null > /dev/null
- echo " + Generating signing request..."
- openssl req -new -sha256 -key "certs/${domain}/privkey.pem" -out "certs/${domain}/cert.csr" -subj "/CN=${domain}/" -reqexts SAN -config <(cat /etc/ssl/openssl.cnf <(printf "[SAN]\nsubjectAltName=%s" "${SAN}")) > /dev/null
fi
+ # Generate signing request config and the actual signing request
+ SAN=""
for altname in $altnames; do
+ SAN+="DNS:${altname}, "
+ done
+ SAN="$(printf '%s' "${SAN}" | sed 's/,\s*$//g')"
+ echo " + Generating signing request..."
+ openssl req -new -sha256 -key "certs/${domain}/privkey.pem" -out "certs/${domain}/cert.csr" -subj "/CN=${domain}/" -reqexts SAN -config <(cat /etc/ssl/openssl.cnf <(printf "[SAN]\nsubjectAltName=%s" "${SAN}")) > /dev/null
+
+ # Request and respond to challenges
+ for altname in $altnames; do
+ # Ask the acme-server for new challenge token and extract them from the resulting json block
echo " + Requesting challenge for ${altname}..."
response="$(signed_request "${CA}/acme/new-authz" '{"resource": "new-authz", "identifier": {"type": "dns", "value": "'"${altname}"'"}}')"
exit 1
fi
+ # Challenge response consists of the challenge token and the thumbprint of our public certificate
keyauth="${challenge_token}.${thumbprint}"
+ # Store challenge response in well-known location and make world-readable (so that a webserver can access it)
printf '%s' "${keyauth}" > "${WELLKNOWN}/${challenge_token}"
chmod a+r "${WELLKNOWN}/${challenge_token}"
+ # Ask the acme-server to verify our challenge and wait until it becomes valid
echo " + Responding to challenge for ${altname}..."
result="$(signed_request "${challenge_uri}" '{"resource": "challenge", "keyAuthorization": "'"${keyauth}"'"}')"
status="$(printf '%s\n' "${result}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
-
if [ ! "${status}" = "pending" ] && [ ! "${status}" = "valid" ]; then
echo " + Challenge is invalid! (${result})"
exit 1
fi
- while [ ! "${status}" = "valid" ]; do
+ while [ "${status}" = "pending" ]; do
status="$(_request get "${challenge_uri}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
+ sleep 1
done
echo " + Challenge is valid!"
done
+ # Finally request certificate from the acme-server and store it in cert.pem
echo " + Requesting certificate..."
csr64="$(openssl req -in "certs/${domain}/cert.csr" -outform DER | urlbase64)"
- crt64="$(signed_request "${CA}/acme/new-cert" '{"resource": "new-cert", "csr": "'"${csr64}"'"}' | base64 -w 64)"
+ crt64="$(signed_request "${CA}/acme/new-cert" '{"resource": "new-cert", "csr": "'"${csr64}"'"}' | openssl base64 -e)"
printf -- '-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----\n' "${crt64}" > "certs/${domain}/cert.pem"
echo " + Done!"
}
+# Check if private key exists, if it doesn't exist yet generate a new one (4096bit rsa key)
register="0"
if [ ! -e "private_key.pem" ]; then
echo "+ Generating account key..."
register="1"
fi
+# Get public components from private key and calculate thumbprint
pubExponent64="$(printf "%06x" "$(openssl rsa -in private_key.pem -noout -text | grep publicExponent | head -1 | cut -d' ' -f2)" | hex2bin | urlbase64)"
pubMod64="$(printf '%s' "$(openssl rsa -in private_key.pem -noout -modulus | cut -d'=' -f2)" | hex2bin | urlbase64)"
-thumbprint="$(printf '%s' "$(printf '%s' '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | sha256sum | awk '{print $1}')" | hex2bin | urlbase64)"
+thumbprint="$(printf '%s' "$(printf '%s' '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | shasum -a 256 | awk '{print $1}')" | hex2bin | urlbase64)"
+# If we generated a new private key in the step above we have to register it with the acme-server
if [ "${register}" = "1" ]; then
echo "+ Registering account key with letsencrypt..."
signed_request "${CA}/acme/new-reg" '{"resource": "new-reg", "agreement": "https://letsencrypt.org/documents/LE-SA-v1.0.1-July-27-2015.pdf"}' > /dev/null
fi
+# Generate certificates for all domains found in domain.txt (TODO: check if certificate already exists and is about to expire)
<domains.txt sed 's/^\s*//g;s/\s*$//g' | grep -v '^#' | grep -v '^$' | while read line; do
sign_domain $line
done