Coverage Report

Created: 2021-02-21 07:20

/src/botan/build/include/botan/aead.h
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/*
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* Interface for AEAD modes
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* (C) 2013 Jack Lloyd
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*
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* Botan is released under the Simplified BSD License (see license.txt)
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*/
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#ifndef BOTAN_AEAD_MODE_H_
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#define BOTAN_AEAD_MODE_H_
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#include <botan/cipher_mode.h>
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namespace Botan {
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/**
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* Interface for AEAD (Authenticated Encryption with Associated Data)
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* modes. These modes provide both encryption and message
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* authentication, and can authenticate additional per-message data
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* which is not included in the ciphertext (for instance a sequence
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* number).
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*/
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class BOTAN_PUBLIC_API(2,0) AEAD_Mode : public Cipher_Mode
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   {
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   public:
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      /**
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      * Create an AEAD mode
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      * @param algo the algorithm to create
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      * @param direction specify if this should be an encryption or decryption AEAD
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      * @param provider optional specification for provider to use
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      * @return an AEAD mode or a null pointer if not available
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      */
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      static std::unique_ptr<AEAD_Mode> create(const std::string& algo,
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                                               Cipher_Dir direction,
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                                               const std::string& provider = "");
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      /**
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      * Create an AEAD mode, or throw
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      * @param algo the algorithm to create
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      * @param direction specify if this should be an encryption or decryption AEAD
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      * @param provider optional specification for provider to use
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      * @return an AEAD mode, or throw an exception
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      */
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      static std::unique_ptr<AEAD_Mode> create_or_throw(const std::string& algo,
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                                                        Cipher_Dir direction,
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                                                        const std::string& provider = "");
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      bool authenticated() const override { return true; }
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      /**
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      * Set associated data that is not included in the ciphertext but
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      * that should be authenticated. Must be called after set_key and
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      * before start.
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      *
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      * Unless reset by another call, the associated data is kept
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      * between messages. Thus, if the AD does not change, calling
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      * once (after set_key) is the optimum.
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      *
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      * @param ad the associated data
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      * @param ad_len length of add in bytes
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      */
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      virtual void set_associated_data(const uint8_t ad[], size_t ad_len) = 0;
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      /**
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      * Set associated data that is not included in the ciphertext but
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      * that should be authenticated. Must be called after set_key and
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      * before start.
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      *
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      * Unless reset by another call, the associated data is kept
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      * between messages. Thus, if the AD does not change, calling
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      * once (after set_key) is the optimum.
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      *
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      * Some AEADs (namely SIV) support multiple AD inputs. For
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      * all other modes only nominal AD input 0 is supported; all
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      * other values of i will cause an exception.
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      *
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      * @param ad the associated data
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      * @param ad_len length of add in bytes
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      */
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      virtual void set_associated_data_n(size_t i, const uint8_t ad[], size_t ad_len);
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      /**
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      * Returns the maximum supported number of associated data inputs which
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      * can be provided to set_associated_data_n
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      *
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      * If returns 0, then no associated data is supported.
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      */
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      virtual size_t maximum_associated_data_inputs() const { return 1; }
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      /**
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      * Most AEADs require the key to be set prior to setting the AD
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      * A few allow the AD to be set even before the cipher is keyed.
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      * Such ciphers would return false from this function.
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      */
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      virtual bool associated_data_requires_key() const { return true; }
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      /**
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      * Set associated data that is not included in the ciphertext but
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      * that should be authenticated. Must be called after set_key and
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      * before start.
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      *
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      * See @ref set_associated_data().
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      *
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      * @param ad the associated data
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      */
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      template<typename Alloc>
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      void set_associated_data_vec(const std::vector<uint8_t, Alloc>& ad)
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         {
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         set_associated_data(ad.data(), ad.size());
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         }
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      /**
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      * Set associated data that is not included in the ciphertext but
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      * that should be authenticated. Must be called after set_key and
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      * before start.
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      *
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      * See @ref set_associated_data().
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      *
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      * @param ad the associated data
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      */
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      template<typename Alloc>
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      void set_ad(const std::vector<uint8_t, Alloc>& ad)
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         {
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         set_associated_data(ad.data(), ad.size());
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         }
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      /**
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      * @return default AEAD nonce size (a commonly supported value among AEAD
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      * modes, and large enough that random collisions are unlikely)
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      */
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      size_t default_nonce_length() const override { return 12; }
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      virtual ~AEAD_Mode() = default;
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   };
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/**
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* Get an AEAD mode by name (eg "AES-128/GCM" or "Serpent/EAX")
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* @param name AEAD name
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* @param direction ENCRYPTION or DECRYPTION
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*/
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inline AEAD_Mode* get_aead(const std::string& name, Cipher_Dir direction)
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   {
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   return AEAD_Mode::create(name, direction, "").release();
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   }
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}
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#endif