Line data    Source code

       1             : // Copyright (c) 2016-2020 The ZCash developers
       2             : // Copyright (c) 2021 The PIVX Core developers
       3             : // Distributed under the MIT software license, see the accompanying
       4             : // file COPYING or https://www.opensource.org/licenses/mit-license.php.
       5             : 
       6             : /*
       7             : See the Zcash protocol specification for more information.
       8             : https://github.com/zcash/zips/blob/master/protocol/protocol.pdf
       9             : */
      10             : 
      11             : #ifndef PIVX_SAPLING_NOTEENCRYPTION_H
      12             : #define PIVX_SAPLING_NOTEENCRYPTION_H
      13             : 
      14             : #include "optional.h"
      15             : #include "sapling/sapling.h"
      16             : #include "uint256.h"
      17             : 
      18             : #include <array>
      19             : 
      20             : namespace libzcash {
      21             : 
      22             : // Ciphertext for the recipient to decrypt
      23             : typedef std::array<unsigned char, ZC_SAPLING_ENCCIPHERTEXT_SIZE> SaplingEncCiphertext;
      24             : typedef std::array<unsigned char, ZC_SAPLING_ENCPLAINTEXT_SIZE> SaplingEncPlaintext;
      25             : 
      26             : // Ciphertext for outgoing viewing key to decrypt
      27             : typedef std::array<unsigned char, ZC_SAPLING_OUTCIPHERTEXT_SIZE> SaplingOutCiphertext;
      28             : typedef std::array<unsigned char, ZC_SAPLING_OUTPLAINTEXT_SIZE> SaplingOutPlaintext;
      29             : 
      30             : //! This is not a thread-safe API.
      31             : class SaplingNoteEncryption {
      32             : protected:
      33             :     // Ephemeral public key
      34             :     uint256 epk;
      35             : 
      36             :     // Ephemeral secret key
      37             :     uint256 esk;
      38             : 
      39             :     bool already_encrypted_enc;
      40             :     bool already_encrypted_out;
      41             : 
      42        1327 :     SaplingNoteEncryption(uint256 epk, uint256 esk) : epk(epk), esk(esk), already_encrypted_enc(false), already_encrypted_out(false) {
      43             : 
      44             :     }
      45             : 
      46             : public:
      47             : 
      48             :     static Optional<SaplingNoteEncryption> FromDiversifier(diversifier_t d);
      49             : 
      50             :     Optional<SaplingEncCiphertext> encrypt_to_recipient(
      51             :         const uint256 &pk_d,
      52             :         const SaplingEncPlaintext &message
      53             :     );
      54             : 
      55             :     SaplingOutCiphertext encrypt_to_ourselves(
      56             :         const uint256 &ovk,
      57             :         const uint256 &cv,
      58             :         const uint256 &cm,
      59             :         const SaplingOutPlaintext &message
      60             :     );
      61             : 
      62        1327 :     uint256 get_epk() const {
      63        1327 :         return epk;
      64             :     }
      65             : 
      66        2648 :     uint256 get_esk() const {
      67        2648 :         return esk;
      68             :     }
      69             : };
      70             : 
      71             : // Attempts to decrypt a Sapling note. This will not check that the contents
      72             : // of the ciphertext are correct.
      73             : Optional<SaplingEncPlaintext> AttemptSaplingEncDecryption(
      74             :     const SaplingEncCiphertext &ciphertext,
      75             :     const uint256 &ivk,
      76             :     const uint256 &epk
      77             : );
      78             : 
      79             : // Attempts to decrypt a Sapling note using outgoing plaintext.
      80             : // This will not check that the contents of the ciphertext are correct.
      81             : Optional<SaplingEncPlaintext> AttemptSaplingEncDecryption (
      82             :     const SaplingEncCiphertext &ciphertext,
      83             :     const uint256 &epk,
      84             :     const uint256 &esk,
      85             :     const uint256 &pk_d
      86             : );
      87             : 
      88             : // Attempts to decrypt a Sapling note. This will not check that the contents
      89             : // of the ciphertext are correct.
      90             : Optional<SaplingOutPlaintext> AttemptSaplingOutDecryption(
      91             :     const SaplingOutCiphertext &ciphertext,
      92             :     const uint256 &ovk,
      93             :     const uint256 &cv,
      94             :     const uint256 &cm,
      95             :     const uint256 &epk
      96             : );
      97             : 
      98             : }
      99             : 
     100             : #endif // PIVX_SAPLING_NOTEENCRYPTION_H