Bug 1352893: Handle non-UTF-8 data in Unix environment variables. r=mstange

MozReview-Commit-ID: 5aRVYQICc7O

--HG--
extra : rebase_source : 6244a8ba08bad6da90496f27e9bb4eaace5e6fb9
extra : amend_source : f997353c8b075c989ace2790ae73330fd375b558

toolkit/modules/subprocess/Subprocess.jsm

@@ -18,6 +18,8 @@ let EXPORTED_SYMBOLS = ["Subprocess"];
 
 var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
 
+Cu.importGlobalProperties(["TextEncoder"]);
+
 Cu.import("resource://gre/modules/AppConstants.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/subprocess/subprocess_common.jsm");
@@ -30,6 +32,19 @@ if (AppConstants.platform == "win") {
                                     "resource://gre/modules/subprocess/subprocess_unix.jsm");
 }
 
+function encodeEnvVar(name, value) {
+  if (typeof name === "string" && typeof value === "string") {
+    return `${name}=${value}`;
+  }
+
+  let encoder = new TextEncoder("utf-8");
+  function encode(val) {
+    return typeof val === "string" ? encoder.encode(val) : val;
+  }
+
+  return Uint8Array.of(...encode(name), ...encode("="), ...encode(value), 0);
+}
+
 /**
  * Allows for creation of and communication with OS-level sub-processes.
  * @namespace
@@ -102,8 +117,8 @@ var Subprocess = {
       Object.assign(environment, options.environment);
     }
 
-    options.environment = Object.keys(environment)
-                                .map(key => `${key}=${environment[key]}`);
+    options.environment = Object.entries(environment)
+                                .map(([key, val]) => encodeEnvVar(key, val));
 
     options.arguments = Array.from(options.arguments || []);
 

toolkit/modules/subprocess/subprocess_shared_unix.js

@@ -41,6 +41,14 @@ var libc = new Library("libc", LIBC_CHOICES, {
     ctypes.char.ptr.ptr.ptr,
   ],
 
+  setenv: [
+    ctypes.default_abi,
+    ctypes.int,
+    ctypes.char.ptr,
+    ctypes.char.ptr,
+    ctypes.int,
+  ],
+
   chdir: [
     ctypes.default_abi,
     ctypes.int,

toolkit/modules/subprocess/subprocess_unix.jsm

@@ -13,6 +13,8 @@
 
 var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
 
+Cu.importGlobalProperties(["TextDecoder"]);
+
 var EXPORTED_SYMBOLS = ["SubprocessImpl"];
 
 Cu.import("resource://gre/modules/ctypes.jsm");
@@ -76,6 +78,21 @@ class Process extends BaseProcess {
   }
 }
 
+// Convert a null-terminated char pointer into a sized char array, and then
+// convert that into a JS typed array.
+// The resulting array will not be null-terminated.
+function ptrToUint8Array(input) {
+  let {cast, uint8_t} = ctypes;
+
+  let len = 0;
+  for (let ptr = cast(input, uint8_t.ptr); ptr.contents; ptr = ptr.increment()) {
+    len++;
+  }
+
+  let aryPtr = cast(input, uint8_t.array(len).ptr);
+  return new Uint8Array(aryPtr.contents);
+}
+
 var SubprocessUnix = {
   Process,
 
@@ -91,13 +108,26 @@ var SubprocessUnix = {
       environ = libc.environ;
     }
 
-    for (let envp = environ; !envp.contents.isNull(); envp = envp.increment()) {
-      let str = envp.contents.readString();
+    const EQUAL = "=".charCodeAt(0);
+    let decoder = new TextDecoder("utf-8", {fatal: true});
 
-      let idx = str.indexOf("=");
-      if (idx >= 0) {
-        yield [str.slice(0, idx),
-               str.slice(idx + 1)];
+    function decode(array) {
+      try {
+        return decoder.decode(array);
+      } catch (e) {
+        return array;
+      }
+    }
+
+    for (let envp = environ; !envp.contents.isNull(); envp = envp.increment()) {
+      let buf = ptrToUint8Array(envp.contents);
+
+      for (let i = 0; i < buf.length; i++) {
+        if (buf[i] == EQUAL) {
+          yield [decode(buf.subarray(0, i)),
+                 decode(buf.subarray(i + 1))];
+          break;
+        }
       }
     }
   },
@@ -146,7 +176,7 @@ var SubprocessUnix = {
     }
 
     let dirs = [];
-    if (environment.PATH) {
+    if (typeof environment.PATH === "string") {
       dirs = environment.PATH.split(":");
     }
 

toolkit/modules/subprocess/test/xpcshell/test_subprocess.js

@@ -716,6 +716,33 @@ add_task(function* test_subprocess_environmentAppend() {
   equal(exitCode, 0, "Got expected exit code");
 });
 
+if (AppConstants.platform !== "win") {
+  add_task(function* test_subprocess_nonASCII() {
+    const {libc} = Cu.import("resource://gre/modules/subprocess/subprocess_unix.jsm", {});
+
+    // Use TextDecoder rather than a string with a \xff escape, since
+    // the latter will automatically be normalized to valid UTF-8.
+    let val = new TextDecoder().decode(Uint8Array.of(1, 255));
+
+    libc.setenv("FOO", Uint8Array.from(val + "\0", c => c.charCodeAt(0)), 1);
+
+    let proc = yield Subprocess.call({
+      command: PYTHON,
+      arguments: ["-u", TEST_SCRIPT, "env", "FOO"],
+    });
+
+    let foo = yield read(proc.stdout);
+
+    equal(foo, val, "Got expected $FOO value");
+
+    env.set("FOO", "");
+
+    let {exitCode} = yield proc.wait();
+
+    equal(exitCode, 0, "Got expected exit code");
+  });
+}
+
 
 add_task(function* test_bad_executable() {
   // Test with a non-executable file.