blob: 5d334c3770d57fc76f5c67c8183fdc99e536a7c4 [file] [log] [blame]
// Copyright (c) 2013 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 <cstddef>
#include <memory>
#include <string>
#include <vector>
#include "absl/strings/string_view.h"
#include "quiche/quic/core/crypto/quic_random.h"
#include "quiche/quic/platform/api/quic_export.h"
#include "quiche/quic/platform/api/quic_mutex.h"
namespace quic {
// CryptoSecretBoxer encrypts small chunks of plaintext (called 'boxing') and
// then, later, can authenticate+decrypt the resulting boxes. This object is
// thread-safe.
class QUIC_EXPORT_PRIVATE CryptoSecretBoxer {
CryptoSecretBoxer(const CryptoSecretBoxer&) = delete;
CryptoSecretBoxer& operator=(const CryptoSecretBoxer&) = delete;
// GetKeySize returns the number of bytes in a key.
static size_t GetKeySize();
// SetKeys sets a list of encryption keys. The first key in the list will be
// used by |Box|, but all supplied keys will be tried by |Unbox|, to handle
// key skew across the fleet. This must be called before |Box| or |Unbox|.
// Keys must be |GetKeySize()| bytes long. No change is made if any key is
// invalid, or if there are no keys supplied.
bool SetKeys(const std::vector<std::string>& keys);
// Box encrypts |plaintext| using a random nonce generated from |rand| and
// returns the resulting ciphertext. Since an authenticator and nonce are
// included, the result will be slightly larger than |plaintext|. The first
// key in the vector supplied to |SetKeys| will be used. |SetKeys| must be
// called before calling this method.
std::string Box(QuicRandom* rand, absl::string_view plaintext) const;
// Unbox takes the result of a previous call to |Box| in |ciphertext| and
// authenticates+decrypts it. If |ciphertext| cannot be decrypted with any of
// the supplied keys, the function returns false. Otherwise, |out_storage| is
// used to store the result and |out| is set to point into |out_storage| and
// contains the original plaintext.
bool Unbox(absl::string_view ciphertext, std::string* out_storage,
absl::string_view* out) const;
struct State;
mutable QuicMutex lock_;
// state_ is an opaque pointer to whatever additional state the concrete
// implementation of CryptoSecretBoxer requires.
std::unique_ptr<State> state_ QUIC_GUARDED_BY(lock_);
} // namespace quic