Merge pull request #121708 from talyz/replace-secret

treewide: Replace uses of `replace-literal` with `replace-secret` to avoid leaking secrets

nixos/modules/services/audio/mpd.nix

@@ -233,14 +233,15 @@ in {
         {
           User = "${cfg.user}";
           ExecStart = "${pkgs.mpd}/bin/mpd --no-daemon /run/mpd/mpd.conf";
-          ExecStartPre = pkgs.writeShellScript "mpd-start-pre" ''
+          ExecStartPre = pkgs.writeShellScript "mpd-start-pre" (''
             set -euo pipefail
             install -m 600 ${mpdConf} /run/mpd/mpd.conf
-            ${optionalString (cfg.credentials != [])
+          '' + optionalString (cfg.credentials != [])
-            "${pkgs.replace}/bin/replace-literal -fe ${
+            (concatStringsSep "\n"
-              concatStringsSep " -a " (imap0 (i: c: "\"{{password-${toString i}}}\" \"$(cat ${c.passwordFile})\"") cfg.credentials)
+              (imap0
-            } /run/mpd/mpd.conf"}
+                (i: c: ''${pkgs.replace-secret}/bin/replace-secret '{{password-${toString i}}}' '${c.passwordFile}' /run/mpd/mpd.conf'')
-          '';
+                cfg.credentials))
+          );
           RuntimeDirectory = "mpd";
           Type = "notify";
           LimitRTPRIO = 50;

nixos/modules/services/audio/mpdscribble.nix

@@ -59,7 +59,7 @@ let
 
   replaceSecret = secretFile: placeholder: targetFile:
     optionalString (secretFile != null) ''
-      ${pkgs.replace}/bin/replace-literal -ef ${placeholder} "$(cat ${secretFile})" ${targetFile}'';
+      ${pkgs.replace-secret}/bin/replace-secret '${placeholder}' '${secretFile}' '${targetFile}' '';
 
   preStart = pkgs.writeShellScript "mpdscribble-pre-start" ''
     cp -f "${cfgTemplate}" "${cfgFile}"

nixos/modules/services/misc/gitlab.nix

@@ -952,7 +952,7 @@ in {
       path = with pkgs; [
         jq
         openssl
-        replace
+        replace-secret
         git
       ];
       serviceConfig = {
@@ -994,8 +994,7 @@ in {
           ${optionalString cfg.smtp.enable ''
               install -m u=rw ${smtpSettings} ${cfg.statePath}/config/initializers/smtp_settings.rb
               ${optionalString (cfg.smtp.passwordFile != null) ''
-                  smtp_password=$(<'${cfg.smtp.passwordFile}')
+                  replace-secret '@smtpPassword@' '${cfg.smtp.passwordFile}' '${cfg.statePath}/config/initializers/smtp_settings.rb'
-                  replace-literal -e '@smtpPassword@' "$smtp_password" '${cfg.statePath}/config/initializers/smtp_settings.rb'
               ''}
           ''}
 

nixos/modules/services/web-apps/discourse.nix

@@ -661,7 +661,7 @@ in
       ];
       path = cfg.package.runtimeDeps ++ [
         postgresqlPackage
-        pkgs.replace
+        pkgs.replace-secret
         cfg.package.rake
       ];
       environment = cfg.package.runtimeEnv // {
@@ -688,10 +688,7 @@ in
 
           mkSecretReplacement = file:
             lib.optionalString (file != null) ''
-              (
+              replace-secret '${file}' '${file}' /run/discourse/config/discourse.conf
-                  password=$(<'${file}')
-                  replace-literal -fe '${file}' "$password" /run/discourse/config/discourse.conf
-              )
             '';
         in ''
           set -o errexit -o pipefail -o nounset -o errtrace
@@ -713,11 +710,12 @@ in
                   cfg.siteSettings
                   "/run/discourse/config/nixos_site_settings.json"
               }
-              install -T -m 0400 -o discourse ${discourseConf} /run/discourse/config/discourse.conf
+              install -T -m 0600 -o discourse ${discourseConf} /run/discourse/config/discourse.conf
               ${mkSecretReplacement cfg.database.passwordFile}
               ${mkSecretReplacement cfg.mail.outgoing.passwordFile}
               ${mkSecretReplacement cfg.redis.passwordFile}
               ${mkSecretReplacement cfg.secretKeyBaseFile}
+              chmod 0400 /run/discourse/config/discourse.conf
           )
 
           discourse-rake db:migrate >>/var/log/discourse/db_migration.log

nixos/modules/services/web-apps/keycloak.nix

@@ -633,6 +633,9 @@ in
             after = databaseServices;
             bindsTo = databaseServices;
             wantedBy = [ "multi-user.target" ];
+            path = with pkgs; [
+              replace-secret
+            ];
             environment = {
               JBOSS_LOG_DIR = "/var/log/keycloak";
               JBOSS_BASE_DIR = "/run/keycloak";
@@ -653,8 +656,7 @@ in
                   install -m 0600 ${cfg.package}/standalone/configuration/*.properties /run/keycloak/configuration
                   install -T -m 0600 ${keycloakConfig} /run/keycloak/configuration/standalone.xml
 
-                  db_password="$(</run/keycloak/secrets/db_password)"
+                  replace-secret '@db-password@' '/run/keycloak/secrets/db_password' /run/keycloak/configuration/standalone.xml
-                  ${pkgs.replace}/bin/replace-literal -fe '@db-password@' "$db_password" /run/keycloak/configuration/standalone.xml
 
                   export JAVA_OPTS=-Djboss.server.config.user.dir=/run/keycloak/configuration
                   ${cfg.package}/bin/add-user-keycloak.sh -u admin -p '${cfg.initialAdminPassword}'

pkgs/build-support/replace-secret/replace-secret.nix

@@ -0,0 +1,35 @@
+{ stdenv, lib, python3 }:
+
+stdenv.mkDerivation {
+  name = "replace-secret";
+  buildInputs = [ python3 ];
+  phases = [ "installPhase" "checkPhase" ];
+  installPhase = ''
+    install -D ${./replace-secret.py} $out/bin/replace-secret
+    patchShebangs $out
+  '';
+  doCheck = true;
+  checkPhase = ''
+    install -m 0600 ${./test/input_file} long_test
+    $out/bin/replace-secret "replace this" ${./test/passwd} long_test
+    $out/bin/replace-secret "and this" ${./test/rsa} long_test
+    diff ${./test/expected_long_output} long_test
+
+    install -m 0600 ${./test/input_file} short_test
+    $out/bin/replace-secret "replace this" <(echo "a") short_test
+    $out/bin/replace-secret "and this" <(echo "b") short_test
+    diff ${./test/expected_short_output} short_test
+  '';
+  meta = with lib; {
+    platforms = platforms.all;
+    maintainers = with maintainers; [ talyz ];
+    license = licenses.mit;
+    description = "Replace a string in one file with a secret from a second file";
+    longDescription = ''
+      Replace a string in one file with a secret from a second file.
+
+      Since the secret is read from a file, it won't be leaked through
+      '/proc/<pid>/cmdline', unlike when 'sed' or 'replace' is used.
+    '';
+  };
+}

pkgs/build-support/replace-secret/replace-secret.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+
+import argparse
+from argparse import RawDescriptionHelpFormatter
+
+description = """
+Replace a string in one file with a secret from a second file.
+
+Since the secret is read from a file, it won't be leaked through
+'/proc/<pid>/cmdline', unlike when 'sed' or 'replace' is used.
+"""
+
+parser = argparse.ArgumentParser(
+    description=description,
+    formatter_class=RawDescriptionHelpFormatter
+)
+parser.add_argument("string_to_replace", help="the string to replace")
+parser.add_argument("secret_file", help="the file containing the secret")
+parser.add_argument("file", help="the file to perform the replacement on")
+args = parser.parse_args()
+
+with open(args.secret_file) as sf, open(args.file, 'r+') as f:
+    old = f.read()
+    secret = sf.read().strip("\n")
+    new_content = old.replace(args.string_to_replace, secret)
+    f.seek(0)
+    f.write(new_content)
+    f.truncate()

pkgs/build-support/replace-secret/test/expected_long_output

@@ -0,0 +1,30 @@
+beginning
+middle $6$UcbJUl5g$HRMfKNKsLTfVbcQb.P5o0bmZUfHDYkWseMSuZ8F5jSIGZZcI3Jnit23f8ZeZOGi4KL86HVM9RYqrpYySOu/fl0 not this
+-----BEGIN RSA PRIVATE KEY-----
+MIIEowIBAAKCAQEAzrru6v5tfwQl6L+rOUjtLo8kbhMUlCLXP7TYngSGrkzPMWe+
+0gB04UAmiPZXfBmvj5fPqYiFjIaEDHE/SD41vJB/RJKKtId2gCAIHhBLkbr+4+60
+yEbLkJci5i4kJC1dt8OKFEzXkaVnwOSgjH+0NwO3bstZ+E70zMXS9+NS71qGsIEb
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+6bf6pVdFZF8d2qJhOPAZRClhTXFKj+pqv+QPzcXr9F/fMr6bhK/G+Oqdnlq2aM4m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+-----END RSA PRIVATE KEY-----
+end

pkgs/build-support/replace-secret/test/expected_short_output

@@ -0,0 +1,4 @@
+beginning
+middle a not this
+b
+end

pkgs/build-support/replace-secret/test/input_file

@@ -0,0 +1,4 @@
+beginning
+middle replace this not this
+and this
+end

pkgs/build-support/replace-secret/test/passwd

@@ -0,0 +1 @@
+$6$UcbJUl5g$HRMfKNKsLTfVbcQb.P5o0bmZUfHDYkWseMSuZ8F5jSIGZZcI3Jnit23f8ZeZOGi4KL86HVM9RYqrpYySOu/fl0

pkgs/build-support/replace-secret/test/rsa

@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+IxvS+8yAZSx6PoyqDI+XFh4RCf5dLGGOkBTAyB7Hs761lsiuEwK5sHmdJ/LQIBot
+v1bjOJb/AA/yxvT8kLUtHQKBgGIA9iwqXJv/EfRNQytDdS0HQ4vHGtJZMr3YRVoa
+kcZD3yieo4wqguLCsf4mPv4FE3CWAphW6f39+yTi9xIWLSy56nOtjdnsf7PDCh8E
+AbL5amSFJly1fKDda6OLjHt/jKa5Osk6ZIa8CP6cA/BrLfXg4rL6cyDQouqJPMDH
+5CHdAoGBAIChjbTyoYvANkoANCK4SuqLUYeiYREfiM3sqHe1xirK1PPHw03ZLITl
+ltjo9qE6kPXWcTBVckTKGFlntyCT283FC0/vMmHo8dTdtxF4/wSbkqs3ORuJ3p5J
+cNtLYGD3vgwLmg6tTur4U60XN+tYDzWGteez8J9GwTMfKJmuS9af
+-----END RSA PRIVATE KEY-----

pkgs/top-level/all-packages.nix

@@ -13592,6 +13592,8 @@ in
 
   remake = callPackage ../development/tools/build-managers/remake { };
 
+  replace-secret = callPackage ../build-support/replace-secret/replace-secret.nix { };
+
   replacement = callPackage ../development/tools/misc/replacement { };
 
   retdec = callPackage ../development/tools/analysis/retdec {