1 files changed, 239 insertions, 0 deletions
diff --git a/xpcom/base/nsID.cpp b/xpcom/base/nsID.cpp
new file mode 100644
index 0000000000..701bf647d1
--- /dev/null
+++ b/xpcom/base/nsID.cpp
@@ -0,0 +1,239 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsID.h"
+
+#include <limits.h>
+
+#include "MainThreadUtils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/RandomNum.h"
+#include "mozilla/Sprintf.h"
+#include "nss.h"
+#include "ScopedNSSTypes.h"
+
+[[nodiscard]] static bool GenerateRandomBytesFromNSS(void* aBuffer,
+                                                     size_t aLength) {
+  MOZ_ASSERT(aBuffer);
+
+  // Bounds check that we can safely truncate size_t `aLength` to an int.
+  if (aLength == 0 || aLength > INT_MAX) {
+    MOZ_ASSERT_UNREACHABLE("Bad aLength");
+    return false;
+  }
+  int len = static_cast<int>(aLength);
+
+  // Only try to use NSS on the main thread.
+  if (!NS_IsMainThread() || !NSS_IsInitialized()) {
+    return false;
+  }
+
+  mozilla::UniquePK11SlotInfo slot(PK11_GetInternalSlot());
+  if (!slot) {
+    MOZ_ASSERT_UNREACHABLE("Null slot");
+    return false;
+  }
+
+  SECStatus srv = PK11_GenerateRandomOnSlot(
+      slot.get(), static_cast<unsigned char*>(aBuffer), len);
+  MOZ_ASSERT(srv == SECSuccess);
+  return (srv == SECSuccess);
+}
+
+nsresult nsID::GenerateUUIDInPlace(nsID& aId) {
+  // Firefox needs to generate some UUIDs before NSS has been initialized. We
+  // prefer NSS's RNG, but if NSS is not available yet or returns an error, fall
+  // back to MFBT's GenerateRandomBytes().
+  if (!GenerateRandomBytesFromNSS(&aId, sizeof(nsID)) &&
+      !mozilla::GenerateRandomBytesFromOS(&aId, sizeof(nsID))) {
+    MOZ_ASSERT_UNREACHABLE("GenerateRandomBytesFromOS() failed");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Put in the version
+  aId.m2 &= 0x0fff;
+  aId.m2 |= 0x4000;
+
+  // Put in the variant
+  aId.m3[0] &= 0x3f;
+  aId.m3[0] |= 0x80;
+
+  return NS_OK;
+}
+
+nsID nsID::GenerateUUID() {
+  nsID uuid;
+  nsresult rv = GenerateUUIDInPlace(uuid);
+  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+  return uuid;
+}
+
+void nsID::Clear() {
+  m0 = 0;
+  m1 = 0;
+  m2 = 0;
+  memset(m3, 0, sizeof(m3));
+}
+
+/**
+ * Multiplies the_int_var with 16 (0x10) and adds the value of the
+ * hexadecimal digit the_char. If it fails it returns false from
+ * the function it's used in.
+ */
+
+#define ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(the_char, the_int_var) \
+  the_int_var = (the_int_var << 4) + the_char;                     \
+  if (the_char >= '0' && the_char <= '9')                          \
+    the_int_var -= '0';                                            \
+  else if (the_char >= 'a' && the_char <= 'f')                     \
+    the_int_var -= 'a' - 10;                                       \
+  else if (the_char >= 'A' && the_char <= 'F')                     \
+    the_int_var -= 'A' - 10;                                       \
+  else                                                             \
+    return false
+
+/**
+ * Parses number_of_chars characters from the char_pointer pointer and
+ * puts the number in the dest_variable. The pointer is moved to point
+ * at the first character after the parsed ones. If it fails it returns
+ * false from the function the macro is used in.
+ */
+
+#define PARSE_CHARS_TO_NUM(char_pointer, dest_variable, number_of_chars) \
+  do {                                                                   \
+    int32_t _i = number_of_chars;                                        \
+    dest_variable = 0;                                                   \
+    while (_i) {                                                         \
+      ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(*char_pointer, dest_variable); \
+      char_pointer++;                                                    \
+      _i--;                                                              \
+    }                                                                    \
+  } while (0)
+
+/**
+ * Parses a hyphen from the char_pointer string. If there is no hyphen there
+ * the function returns false from the function it's used in. The
+ * char_pointer is advanced one step.
+ */
+
+#define PARSE_HYPHEN(char_pointer) \
+  if (*(char_pointer++) != '-') return false
+
+/*
+ * Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} string into
+ * an nsID. It can also handle the old format without the { and }.
+ */
+
+bool nsID::Parse(const char* aIDStr) {
+  /* Optimized for speed */
+  if (!aIDStr) {
+    return false;
+  }
+
+  bool expectFormat1 = (aIDStr[0] == '{');
+  if (expectFormat1) {
+    ++aIDStr;
+  }
+
+  PARSE_CHARS_TO_NUM(aIDStr, m0, 8);
+  PARSE_HYPHEN(aIDStr);
+  PARSE_CHARS_TO_NUM(aIDStr, m1, 4);
+  PARSE_HYPHEN(aIDStr);
+  PARSE_CHARS_TO_NUM(aIDStr, m2, 4);
+  PARSE_HYPHEN(aIDStr);
+  int i;
+  for (i = 0; i < 2; ++i) {
+    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
+  }
+  PARSE_HYPHEN(aIDStr);
+  while (i < 8) {
+    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
+    i++;
+  }
+
+  return expectFormat1 ? *aIDStr == '}' : true;
+}
+
+#ifndef XPCOM_GLUE_AVOID_NSPR
+
+/*
+ * Returns a managed string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
+ * format.
+ */
+nsIDToCString nsID::ToString() const { return nsIDToCString(*this); }
+
+static const char sHexChars[256 * 2 + 1] =
+    "000102030405060708090a0b0c0d0e0f"
+    "101112131415161718191a1b1c1d1e1f"
+    "202122232425262728292a2b2c2d2e2f"
+    "303132333435363738393a3b3c3d3e3f"
+    "404142434445464748494a4b4c4d4e4f"
+    "505152535455565758595a5b5c5d5e5f"
+    "606162636465666768696a6b6c6d6e6f"
+    "707172737475767778797a7b7c7d7e7f"
+    "808182838485868788898a8b8c8d8e8f"
+    "909192939495969798999a9b9c9d9e9f"
+    "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
+    "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
+    "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
+    "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
+    "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
+    "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+
+// Writes a zero-padded 8-bit integer as lowercase hex into aDest[0..2]
+static void ToHex8Bit(uint8_t aValue, char* aDest) {
+  aDest[0] = sHexChars[2 * aValue];
+  aDest[1] = sHexChars[2 * aValue + 1];
+}
+
+// Writes a zero-padded 16-bit integer as lowercase hex into aDest[0..4]
+static void ToHex16Bit(uint16_t aValue, char* aDest) {
+  const uint8_t hi = (aValue >> 8);
+  const uint8_t lo = aValue;
+  ToHex8Bit(hi, &aDest[0]);
+  ToHex8Bit(lo, &aDest[2]);
+}
+
+// Writes a zero-padded 32-bit integer as lowercase hex into aDest[0..8]
+static void ToHex32Bit(uint32_t aValue, char* aDest) {
+  const uint16_t hi = (aValue >> 16);
+  const uint16_t lo = aValue;
+  ToHex16Bit(hi, &aDest[0]);
+  ToHex16Bit(lo, &aDest[4]);
+}
+
+void nsID::ToProvidedString(char (&aDest)[NSID_LENGTH]) const {
+  // Stringify manually, for best performance.
+  //
+  // "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}"
+  // "{ecc35fd2-9029-4287-a826-b0a241d48d31}"
+  aDest[0] = '{';
+  ToHex32Bit(m0, &aDest[1]);
+  aDest[9] = '-';
+  ToHex16Bit(m1, &aDest[10]);
+  aDest[14] = '-';
+  ToHex16Bit(m2, &aDest[15]);
+  aDest[19] = '-';
+  ToHex8Bit(m3[0], &aDest[20]);
+  ToHex8Bit(m3[1], &aDest[22]);
+  aDest[24] = '-';
+  ToHex8Bit(m3[2], &aDest[25]);
+  ToHex8Bit(m3[3], &aDest[27]);
+  ToHex8Bit(m3[4], &aDest[29]);
+  ToHex8Bit(m3[5], &aDest[31]);
+  ToHex8Bit(m3[6], &aDest[33]);
+  ToHex8Bit(m3[7], &aDest[35]);
+  aDest[37] = '}';
+  aDest[38] = '\0';
+}
+
+#endif  // XPCOM_GLUE_AVOID_NSPR
+
+nsID* nsID::Clone() const {
+  auto id = static_cast<nsID*>(moz_xmalloc(sizeof(nsID)));
+  *id = *this;
+  return id;
+}