7 # default config values
8 CA="https://acme-v01.api.letsencrypt.org"
9 LICENSE="https://letsencrypt.org/documents/LE-SA-v1.0.1-July-27-2015.pdf"
13 umask 077 # paranoid umask, we're creating private keys
20 # urlbase64: base64 encoded string with '+' replaced with '-' and '/' replaced with '_'
21 openssl base64 -e | anti_newline | sed -r 's/=*$//g' | tr '+/' '-_'
25 # Store hex string from stdin
30 for ((i=0; i<${#tmphex}; i+=1)); do
31 test "${tmphex:$i:1}" == " " || hex="${hex}${tmphex:$i:1}"
35 test $((${#hex} & 1)) == 0 || hex="0${hex}"
37 # Convert to escaped string
39 for ((i=0; i<${#hex}; i+=2)); do
40 escapedhex=$escapedhex\\x${hex:$i:2}
43 # Convert to binary data
44 printf "${escapedhex}"
49 if [ "${1}" = "head" ]; then
50 curl -sSf -I "${2}" 2>"${temperr}"
51 elif [ "${1}" = "get" ]; then
52 curl -sSf "${2}" 2>"${temperr}"
53 elif [ "${1}" = "post" ]; then
54 curl -sSf "${2}" -d "${3}" 2>"${temperr}"
56 if [ -s "${temperr}" ]; then
57 echo " + ERROR: An error occurred while sending ${1}-request to ${2} ($(<"${temperr}"))" >&2
65 # Encode payload as urlbase64
66 payload64="$(printf '%s' "${2}" | urlbase64)"
68 # Retrieve nonce from acme-server
69 nonce="$(_request head "${CA}/directory" | grep Replay-Nonce: | awk -F ': ' '{print $2}' | anti_newline)"
71 # Build header with just our public key and algorithm information
72 header='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}}'
74 # Build another header which also contains the previously received nonce and encode it as urlbase64
75 protected='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}, "nonce": "'"${nonce}"'"}'
76 protected64="$(printf '%s' "${protected}" | urlbase64)"
78 # Sign header with nonce and our payload with our private key and encode signature as urlbase64
79 signed64="$(printf '%s' "${protected64}.${payload64}" | openssl dgst -sha256 -sign private_key.pem | urlbase64)"
81 # Send header + extended header + payload + signature to the acme-server
82 data='{"header": '"${header}"', "protected": "'"${protected64}"'", "payload": "'"${payload64}"'", "signature": "'"${signed64}"'"}'
84 _request post "${1}" "${data}"
90 echo "Signing domain ${1} (${*})..."
92 # If there is no existing certificate directory we need a new private key
93 if [ ! -e "certs/${domain}" ]; then
94 mkdir "certs/${domain}"
95 echo " + Generating private key..."
96 openssl genrsa -out "certs/${domain}/privkey.pem" 4096 2> /dev/null > /dev/null
99 # Generate signing request config and the actual signing request
101 for altname in $altnames; do
102 SAN+="DNS:${altname}, "
104 SAN="$(printf '%s' "${SAN}" | sed 's/,\s*$//g')"
105 echo " + Generating signing request..."
106 openssl req -new -sha256 -key "certs/${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
108 # Request and respond to challenges
109 for altname in $altnames; do
110 # Ask the acme-server for new challenge token and extract them from the resulting json block
111 echo " + Requesting challenge for ${altname}..."
112 response="$(signed_request "${CA}/acme/new-authz" '{"resource": "new-authz", "identifier": {"type": "dns", "value": "'"${altname}"'"}}')"
114 challenge_token="$(printf '%s\n' "${response}" | grep -Eo '"challenges":[^\[]*\[[^]]*]' | sed 's/{/\n{/g' | grep 'http-01' | grep -Eo '"token":\s*"[^"]*"' | cut -d'"' -f4 | sed 's/[^A-Za-z0-9_\-]/_/g')"
115 challenge_uri="$(printf '%s\n' "${response}" | grep -Eo '"challenges":[^\[]*\[[^]]*]' | sed 's/{/\n{/g' | grep 'http-01' | grep -Eo '"uri":\s*"[^"]*"' | cut -d'"' -f4)"
117 if [ -z "${challenge_token}" ] || [ -z "${challenge_uri}" ]; then
118 echo " + Error: Can't retrieve challenges (${response})"
122 # Challenge response consists of the challenge token and the thumbprint of our public certificate
123 keyauth="${challenge_token}.${thumbprint}"
125 # Store challenge response in well-known location and make world-readable (so that a webserver can access it)
126 printf '%s' "${keyauth}" > "${WELLKNOWN}/${challenge_token}"
127 chmod a+r "${WELLKNOWN}/${challenge_token}"
129 # Ask the acme-server to verify our challenge and wait until it becomes valid
130 echo " + Responding to challenge for ${altname}..."
131 result="$(signed_request "${challenge_uri}" '{"resource": "challenge", "keyAuthorization": "'"${keyauth}"'"}')"
133 status="$(printf '%s\n' "${result}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
134 if [ ! "${status}" = "pending" ] && [ ! "${status}" = "valid" ]; then
135 echo " + Challenge is invalid! (${result})"
139 while [ "${status}" = "pending" ]; do
140 status="$(_request get "${challenge_uri}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
144 echo " + Challenge is valid!"
147 # Finally request certificate from the acme-server and store it in cert.pem
148 echo " + Requesting certificate..."
149 csr64="$(openssl req -in "certs/${domain}/cert.csr" -outform DER | urlbase64)"
150 crt64="$(signed_request "${CA}/acme/new-cert" '{"resource": "new-cert", "csr": "'"${csr64}"'"}' | openssl base64 -e)"
151 printf -- '-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----\n' "${crt64}" > "certs/${domain}/cert.pem"
155 # Check if private key exists, if it doesn't exist yet generate a new one (4096bit rsa key)
157 if [ ! -e "private_key.pem" ]; then
158 echo "+ Generating account key..."
159 openssl genrsa -out "private_key.pem" 4096 2> /dev/null > /dev/null
163 # Get public components from private key and calculate thumbprint
164 pubExponent64="$(printf "%06x" "$(openssl rsa -in private_key.pem -noout -text | grep publicExponent | head -1 | cut -d' ' -f2)" | hex2bin | urlbase64)"
165 pubMod64="$(printf '%s' "$(openssl rsa -in private_key.pem -noout -modulus | cut -d'=' -f2)" | hex2bin | urlbase64)"
167 thumbprint="$(printf '%s' "$(printf '%s' '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | shasum -a 256 | awk '{print $1}')" | hex2bin | urlbase64)"
169 # If we generated a new private key in the step above we have to register it with the acme-server
170 if [ "${register}" = "1" ]; then
171 echo "+ Registering account key with letsencrypt..."
172 signed_request "${CA}/acme/new-reg" '{"resource": "new-reg", "agreement": "'"$LICENSE"'"}' > /dev/null
175 # Generate certificates for all domains found in domain.txt (TODO: check if certificate already exists and is about to expire)
176 <domains.txt sed 's/^\s*//g;s/\s*$//g' | grep -v '^#' | grep -v '^$' | while read line; do