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// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/token.h"
#include <inttypes.h>
#include <array>
#include <optional>
#include <string_view>
#include "base/check.h"
#include "base/hash/hash.h"
#include "base/pickle.h"
#include "base/rand_util.h"
#include "base/strings/stringprintf.h"
namespace base {
// static
Token Token::CreateRandom() {
Token token;
// Use base::RandBytes instead of crypto::RandBytes, because crypto calls the
// base version directly, and to prevent the dependency from base/ to crypto/.
RandBytes(byte_span_from_ref(token));
CHECK(!token.is_zero());
return token;
}
std::string Token::ToString() const {
return StringPrintf("%016" PRIX64 "%016" PRIX64, words_[0], words_[1]);
}
// static
std::optional<Token> Token::FromString(std::string_view string_representation) {
if (string_representation.size() != 32) {
return std::nullopt;
}
std::array<uint64_t, 2> words;
for (size_t i = 0; i < 2; i++) {
uint64_t word = 0;
// This j loop is similar to HexStringToUInt64 but we are intentionally
// strict about case, accepting 'A' but rejecting 'a'.
for (size_t j = 0; j < 16; j++) {
const char c = string_representation[(16 * i) + j];
if (('0' <= c) && (c <= '9')) {
word = (word << 4) | static_cast<uint64_t>(c - '0');
} else if (('A' <= c) && (c <= 'F')) {
word = (word << 4) | static_cast<uint64_t>(c - 'A' + 10);
} else {
return std::nullopt;
}
}
words[i] = word;
}
return std::optional<Token>(std::in_place, words[0], words[1]);
}
void WriteTokenToPickle(Pickle* pickle, const Token& token) {
pickle->WriteUInt64(token.high());
pickle->WriteUInt64(token.low());
}
std::optional<Token> ReadTokenFromPickle(PickleIterator* pickle_iterator) {
uint64_t high;
if (!pickle_iterator->ReadUInt64(&high)) {
return std::nullopt;
}
uint64_t low;
if (!pickle_iterator->ReadUInt64(&low)) {
return std::nullopt;
}
return Token(high, low);
}
size_t TokenHash::operator()(const Token& token) const {
return HashInts64(token.high(), token.low());
}
} // namespace base
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