// 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 #include #include #include "base/rand_util.h" #include "base/strings/string_util.h" #include "base/strings/stringprintf.h" namespace base { namespace { template constexpr bool IsLowerHexDigit(Char c) { return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'); } constexpr bool IsHyphenPosition(size_t i) { return i == 8 || i == 13 || i == 18 || i == 23; } // Returns a canonical GUID string given that `input` is validly formatted // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, such that x is a hexadecimal digit. // If `strict`, x must be a lower-case hexadecimal digit. template std::string GetCanonicalGUIDInternal(StringPieceType input, bool strict) { using CharType = typename StringPieceType::value_type; constexpr size_t kGUIDLength = 36; if (input.length() != kGUIDLength) return std::string(); std::string lowercase_; lowercase_.resize(kGUIDLength); for (size_t i = 0; i < input.length(); ++i) { CharType current = input[i]; if (IsHyphenPosition(i)) { if (current != '-') return std::string(); lowercase_[i] = '-'; } else { if (strict ? !IsLowerHexDigit(current) : !IsHexDigit(current)) return std::string(); lowercase_[i] = static_cast(ToLowerASCII(current)); } } return lowercase_; } } // namespace std::string GenerateGUID() { GUID guid = GUID::GenerateRandomV4(); return guid.AsLowercaseString(); } bool IsValidGUID(StringPiece input) { return !GetCanonicalGUIDInternal(input, /*strict=*/false).empty(); } bool IsValidGUID(StringPiece16 input) { return !GetCanonicalGUIDInternal(input, /*strict=*/false).empty(); } bool IsValidGUIDOutputString(StringPiece input) { return !GetCanonicalGUIDInternal(input, /*strict=*/true).empty(); } std::string RandomDataToGUIDString(const uint64_t bytes[2]) { return StringPrintf( "%08x-%04x-%04x-%04x-%012llx", static_cast(bytes[0] >> 32), static_cast((bytes[0] >> 16) & 0x0000ffff), static_cast(bytes[0] & 0x0000ffff), static_cast(bytes[1] >> 48), bytes[1] & 0x0000ffff'ffffffffULL); } // static GUID GUID::GenerateRandomV4() { 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/. 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; GUID guid; guid.lowercase_ = RandomDataToGUIDString(sixteen_bytes); return guid; } // static GUID GUID::ParseCaseInsensitive(StringPiece input) { GUID guid; guid.lowercase_ = GetCanonicalGUIDInternal(input, /*strict=*/false); return guid; } // static GUID GUID::ParseCaseInsensitive(StringPiece16 input) { GUID guid; guid.lowercase_ = GetCanonicalGUIDInternal(input, /*strict=*/false); return guid; } // static GUID GUID::ParseLowercase(StringPiece input) { GUID guid; guid.lowercase_ = GetCanonicalGUIDInternal(input, /*strict=*/true); return guid; } // static GUID GUID::ParseLowercase(StringPiece16 input) { GUID guid; guid.lowercase_ = GetCanonicalGUIDInternal(input, /*strict=*/true); return guid; } GUID::GUID() = default; GUID::GUID(const GUID& other) = default; GUID& GUID::operator=(const GUID& other) = default; GUID::GUID(GUID&& other) = default; GUID& GUID::operator=(GUID&& other) = default; const std::string& GUID::AsLowercaseString() const { return lowercase_; } bool GUID::operator==(const GUID& other) const { return AsLowercaseString() == other.AsLowercaseString(); } bool GUID::operator!=(const GUID& other) const { return !(*this == other); } bool GUID::operator<(const GUID& other) const { return AsLowercaseString() < other.AsLowercaseString(); } bool GUID::operator<=(const GUID& other) const { return *this < other || *this == other; } bool GUID::operator>(const GUID& other) const { return !(*this <= other); } bool GUID::operator>=(const GUID& other) const { return !(*this < other); } std::ostream& operator<<(std::ostream& out, const GUID& guid) { return out << guid.AsLowercaseString(); } } // namespace base