Increase platform abstraction cohesion

utilities/prosody/modules/mod_auth_gia.lua

@@ -0,0 +1,84 @@
+-- GIA auth provider for legacy Prosody builds that do not ship
+-- external auth modules. Delegates auth checks to external_auth_command.
+
+local new_sasl = require "util.sasl".new;
+
+local host = module.host;
+local log = module._log;
+local auth_cmd = module:get_option_string(
+    "external_auth_command",
+    "/code/utilities/prosody/auth_django.sh"
+);
+
+local provider = {};
+
+local function shell_quote(value)
+    return "'" .. tostring(value or ""):gsub("'", "'\\''") .. "'";
+end
+
+local function run_external(line)
+    local cmd = "printf %s\\\\n " .. shell_quote(line) .. " | " .. shell_quote(auth_cmd);
+    local handle = io.popen(cmd, "r");
+    if not handle then
+        return false;
+    end
+    local output = handle:read("*a") or "";
+    handle:close();
+    output = output:gsub("%s+", "");
+    return output == "1";
+end
+
+function provider.test_password(username, password)
+    if not username or username == "" then
+        return nil, "Auth failed. Invalid username.";
+    end
+    if not password or password == "" then
+        return nil, "Auth failed. Invalid password.";
+    end
+    local ok = run_external("auth:" .. username .. ":" .. host .. ":" .. password);
+    if ok then
+        return true;
+    end
+    return nil, "Auth failed. Invalid username or password.";
+end
+
+function provider.user_exists(username)
+    if not username or username == "" then
+        return nil, "Auth failed. Invalid username.";
+    end
+    if run_external("isuser:" .. username .. ":" .. host) then
+        return true;
+    end
+    return nil, "Auth failed. Invalid username.";
+end
+
+function provider.set_password()
+    return nil, "method not implemented";
+end
+
+function provider.users()
+    return function() return nil end;
+end
+
+function provider.create_user()
+    return nil, "method not implemented";
+end
+
+function provider.delete_user()
+    return nil, "method not implemented";
+end
+
+function provider.get_sasl_handler()
+    return new_sasl(host, {
+        plain_test = function(_, username, password)
+            local ok = provider.test_password(username, password);
+            if ok then
+                return true, true;
+            end
+            return false, nil;
+        end
+    });
+end
+
+log("debug", "initializing GIA auth provider for host '%s'", host);
+module:provides("auth", provider);