replace echo (-n) with printf

printf is more portable and never interprets any escape characters.

diff --git a/letsencrypt.sh b/letsencrypt.sh
index e941e311fbee79aad1354b5c76ad6acb5099281e..04c150d5368b3226bdf7294dd0ead730d2e5cfc7 100755 (executable)
--- a/letsencrypt.sh
+++ b/letsencrypt.sh
@@ -12,16 +12,16 @@ hex2bin() {
 }
 
 signed_request() {
-  payload64="$(echo -n "${2}" | urlbase64)"
+  payload64="$(printf '%s' "${2}" | urlbase64)"
 
   nonce="$(curl -s -I "${CA}"/directory | grep Replay-Nonce | awk -F ': ' '{print $2}' | tr -d '\n\r')"
 
   header='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}}'
 
   protected='{"alg": "RS256", "jwk": {"e": "'"${pubExponent64}"'", "kty": "RSA", "n": "'"${pubMod64}"'"}, "nonce": "'"${nonce}"'"}'
-  protected64="$(echo -n "${protected}" | urlbase64)"
+  protected64="$(printf '%s' "${protected}" | urlbase64)"
 
-  signed64="$(echo -n "${protected64}.${payload64}" | openssl dgst -sha256 -sign private_key.pem | urlbase64)"
+  signed64="$(printf '%s' "${protected64}.${payload64}" | openssl dgst -sha256 -sign private_key.pem | urlbase64)"
 
   data='{"header": '"${header}"', "protected": "'"${protected64}"'", "payload": "'"${payload64}"'", "signature": "'"${signed64}"'"}'
 
@@ -37,7 +37,7 @@ sign_domain() {
     for altname in $altnames; do
       SAN+="DNS:${altname}, "
     done
-    SAN="$(echo -n "${SAN}" | sed 's/,\s*$//g')"
+    SAN="$(printf '%s' "${SAN}" | sed 's/,\s*$//g')"
 
     mkdir "certs/${domain}"
 
@@ -51,8 +51,8 @@ sign_domain() {
     echo "  + Requesting challenge for ${altname}..."
     response="$(signed_request "${CA}/acme/new-authz" '{"resource": "new-authz", "identifier": {"type": "dns", "value": "'"${altname}"'"}}')"
 
-    challenge_token="$(echo "${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')"
-    challenge_uri="$(echo "${response}" | grep -Eo '"challenges":[^\[]*\[[^]]*]' | sed 's/{/\n{/g' | grep 'http-01' | grep -Eo '"uri":\s*"[^"]*"' | cut -d'"' -f4)"
+    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')"
+    challenge_uri="$(printf '%s\n' "${response}" | grep -Eo '"challenges":[^\[]*\[[^]]*]' | sed 's/{/\n{/g' | grep 'http-01' | grep -Eo '"uri":\s*"[^"]*"' | cut -d'"' -f4)"
 
     if [ "${challenge_token}" = "" ] || [ "${challenge_uri}" = "" ]; then
       echo "  + Error: Can't retrieve challenges (${response})"
@@ -61,12 +61,12 @@ sign_domain() {
 
     keyauth="${challenge_token}.${thumbprint}"
 
-    echo -n "${keyauth}" > "${WELLKNOWN}/${challenge_token}"
+    printf '%s' "${keyauth}" > "${WELLKNOWN}/${challenge_token}"
 
     echo "  + Responding to challenge for ${altname}..."
     result="$(signed_request "${challenge_uri}" '{"resource": "challenge", "keyAuthorization": "'"${keyauth}"'"}')"
 
-    status="$(echo "${result}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
+    status="$(printf '%s\n' "${result}" | grep -Eo '"status":\s*"[^"]*"' | cut -d'"' -f4)"
 
     if [ ! "${status}" = "pending" ] && [ ! "${status}" = "valid" ]; then
       echo "  + Challenge is invalid! (${result})"
@@ -83,7 +83,7 @@ sign_domain() {
   echo "  + Requesting certificate..."
   csr64="$(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)"
-  echo -e "-----BEGIN CERTIFICATE-----\n${crt64}\n-----END CERTIFICATE-----\n" > "certs/${domain}/cert.pem"
+  printf -- '-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----\n' "${crt64}" > "certs/${domain}/cert.pem"
   echo "  + Done!"
 }
 
@@ -95,9 +95,9 @@ if [ ! -e "private_key.pem" ]; then
 fi
 
 pubExponent64="$(printf "%06x" "$(openssl rsa -in private_key.pem -noout -text | grep publicExponent | head -1 | cut -d' ' -f2)" | hex2bin | urlbase64)"
-pubMod64="$(echo -n "$(openssl rsa -in private_key.pem -noout -modulus | cut -d'=' -f2)" | hex2bin | urlbase64)"
+pubMod64="$(printf '%s' "$(openssl rsa -in private_key.pem -noout -modulus | cut -d'=' -f2)" | hex2bin | urlbase64)"
 
-thumbprint="$(echo -n "$(echo -n '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | sha256sum | awk '{print $1}')" | hex2bin | urlbase64)"
+thumbprint="$(printf '%s' "$(printf '%s' '{"e":"'"${pubExponent64}"'","kty":"RSA","n":"'"${pubMod64}"'"}' | sha256sum | awk '{print $1}')" | hex2bin | urlbase64)"
 
 if [ "${register}" = "1" ]; then
   echo "+ Registering account key with letsencrypt..."