| // 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 <ostream> |
| |
| #include "base/rand_util.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/stringprintf.h" |
| |
| namespace base { |
| |
| namespace { |
| |
| template <typename Char> |
| 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 <typename StringPieceType> |
| 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] = 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<uint32_t>(bytes[0] >> 32), |
| static_cast<uint32_t>((bytes[0] >> 16) & 0x0000ffff), |
| static_cast<uint32_t>(bytes[0] & 0x0000ffff), |
| static_cast<uint32_t>(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; |
| |
| 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 |