Repo created

TMessagesProj/jni/voip/webrtc/base/guid.cc

@@ -0,0 +1,90 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/guid.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/rand_util.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+
+namespace base {
+
+namespace {
+
+template <typename Char>
+bool IsLowerHexDigit(Char c) {
+  return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f');
+}
+
+template <typename StringPieceType>
+bool IsValidGUIDInternal(StringPieceType guid, bool strict) {
+  using CharType = typename StringPieceType::value_type;
+
+  const size_t kGUIDLength = 36U;
+  if (guid.length() != kGUIDLength)
+    return false;
+
+  for (size_t i = 0; i < guid.length(); ++i) {
+    CharType current = guid[i];
+    if (i == 8 || i == 13 || i == 18 || i == 23) {
+      if (current != '-')
+        return false;
+    } else {
+      if (strict ? !IsLowerHexDigit(current) : !IsHexDigit(current))
+        return false;
+    }
+  }
+
+  return true;
+}
+
+}  // namespace
+
+std::string GenerateGUID() {
+  uint64_t sixteen_bytes[2];
+  // Use base::RandBytes instead of crypto::RandBytes, because crypto calls the
+  // base version directly, and to prevent the dependency from base/ to crypto/.
+  base::RandBytes(&sixteen_bytes, sizeof(sixteen_bytes));
+
+  // Set the GUID to version 4 as described in RFC 4122, section 4.4.
+  // The format of GUID version 4 must be xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx,
+  // where y is one of [8, 9, A, B].
+
+  // Clear the version bits and set the version to 4:
+  sixteen_bytes[0] &= 0xffffffff'ffff0fffULL;
+  sixteen_bytes[0] |= 0x00000000'00004000ULL;
+
+  // Set the two most significant bits (bits 6 and 7) of the
+  // clock_seq_hi_and_reserved to zero and one, respectively:
+  sixteen_bytes[1] &= 0x3fffffff'ffffffffULL;
+  sixteen_bytes[1] |= 0x80000000'00000000ULL;
+
+  return RandomDataToGUIDString(sixteen_bytes);
+}
+
+bool IsValidGUID(base::StringPiece guid) {
+  return IsValidGUIDInternal(guid, false /* strict */);
+}
+
+bool IsValidGUID(base::StringPiece16 guid) {
+  return IsValidGUIDInternal(guid, false /* strict */);
+}
+
+bool IsValidGUIDOutputString(base::StringPiece guid) {
+  return IsValidGUIDInternal(guid, true /* strict */);
+}
+
+std::string RandomDataToGUIDString(const uint64_t bytes[2]) {
+  return StringPrintf("%08x-%04x-%04x-%04x-%012llx",
+                      static_cast<unsigned int>(bytes[0] >> 32),
+                      static_cast<unsigned int>((bytes[0] >> 16) & 0x0000ffff),
+                      static_cast<unsigned int>(bytes[0] & 0x0000ffff),
+                      static_cast<unsigned int>(bytes[1] >> 48),
+                      bytes[1] & 0x0000ffff'ffffffffULL);
+}
+
+}  // namespace base