| // 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. |
| |
| #ifndef QUICHE_QUIC_CORE_CRYPTO_QUIC_DECRYPTER_H_ |
| #define QUICHE_QUIC_CORE_CRYPTO_QUIC_DECRYPTER_H_ |
| |
| #include <cstddef> |
| #include <cstdint> |
| #include <memory> |
| #include <string> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/quic/core/crypto/quic_crypter.h" |
| #include "quiche/quic/core/quic_data_reader.h" |
| #include "quiche/quic/core/quic_packets.h" |
| #include "quiche/quic/platform/api/quic_export.h" |
| |
| namespace quic { |
| |
| class QUICHE_EXPORT QuicDecrypter : public QuicCrypter { |
| public: |
| virtual ~QuicDecrypter() {} |
| |
| static std::unique_ptr<QuicDecrypter> Create(const ParsedQuicVersion& version, |
| QuicTag algorithm); |
| |
| // Creates an IETF QuicDecrypter based on |cipher_suite| which must be an id |
| // returned by SSL_CIPHER_get_id. The caller is responsible for taking |
| // ownership of the new QuicDecrypter. |
| static std::unique_ptr<QuicDecrypter> CreateFromCipherSuite( |
| uint32_t cipher_suite); |
| |
| // Sets the encryption key. Returns true on success, false on failure. |
| // |DecryptPacket| may not be called until |SetDiversificationNonce| is |
| // called and the preliminary keying material will be combined with that |
| // nonce in order to create the actual key and nonce-prefix. |
| // |
| // If this function is called, neither |SetKey| nor |SetNoncePrefix| may be |
| // called. |
| virtual bool SetPreliminaryKey(absl::string_view key) = 0; |
| |
| // SetDiversificationNonce uses |nonce| to derive final keys based on the |
| // input keying material given by calling |SetPreliminaryKey|. |
| // |
| // Calling this function is a no-op if |SetPreliminaryKey| hasn't been |
| // called. |
| virtual bool SetDiversificationNonce(const DiversificationNonce& nonce) = 0; |
| |
| // Populates |output| with the decrypted |ciphertext| and populates |
| // |output_length| with the length. Returns 0 if there is an error. |
| // |output| size is specified by |max_output_length| and must be |
| // at least as large as the ciphertext. |packet_number| is |
| // appended to the |nonce_prefix| value provided in SetNoncePrefix() |
| // to form the nonce. |
| // TODO(wtc): add a way for DecryptPacket to report decryption failure due |
| // to non-authentic inputs, as opposed to other reasons for failure. |
| virtual bool DecryptPacket(uint64_t packet_number, |
| absl::string_view associated_data, |
| absl::string_view ciphertext, char* output, |
| size_t* output_length, |
| size_t max_output_length) = 0; |
| |
| // Reads a sample of ciphertext from |sample_reader| and uses the header |
| // protection key to generate a mask to use for header protection. If |
| // successful, this function returns this mask, which is at least 5 bytes |
| // long. Callers can detect failure by checking if the output string is empty. |
| virtual std::string GenerateHeaderProtectionMask( |
| QuicDataReader* sample_reader) = 0; |
| |
| // The ID of the cipher. Return 0x03000000 ORed with the 'cryptographic suite |
| // selector'. |
| virtual uint32_t cipher_id() const = 0; |
| |
| // Returns the maximum number of packets that can safely fail decryption with |
| // this decrypter. |
| virtual QuicPacketCount GetIntegrityLimit() const = 0; |
| |
| // For use by unit tests only. |
| virtual absl::string_view GetKey() const = 0; |
| virtual absl::string_view GetNoncePrefix() const = 0; |
| |
| static void DiversifyPreliminaryKey(absl::string_view preliminary_key, |
| absl::string_view nonce_prefix, |
| const DiversificationNonce& nonce, |
| size_t key_size, size_t nonce_prefix_size, |
| std::string* out_key, |
| std::string* out_nonce_prefix); |
| }; |
| |
| } // namespace quic |
| |
| #endif // QUICHE_QUIC_CORE_CRYPTO_QUIC_DECRYPTER_H_ |