donau

Donation authority for GNU Taler (experimental)
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donau_signatures.c (3190B)

      1 /*
      2   This file is part of TALER
      3   Copyright (C) 2021, 2022 Taler Systems SA
      4 
      5   TALER is free software; you can redistribute it and/or modify it under the
      6   terms of the GNU General Public License as published by the Free Software
      7   Foundation; either version 3, or (at your option) any later version.
      8 
      9   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
     10   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     11   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
     12 
     13   You should have received a copy of the GNU General Public License along with
     14   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
     15 */
     16 /**
     17  * @file donau_signatures.c
     18  * @brief Utility functions for Taler donau security module signatures
     19  * @author Christian Grothoff
     20  * @author Lukas Matyja
     21  */
     22 #include "donau_config.h"
     23 #include <taler/taler_util.h>
     24 #include <taler/taler_signatures.h>
     25 #include "donau_util.h"
     26 #include "donau_signatures.h"
     27 
     28 GNUNET_NETWORK_STRUCT_BEGIN
     29 
     30 /**
     31  * @brief Format used to generate the signature/donation statement
     32  * over the total amount and a donor identifier of a year.
     33  */
     34 struct DONAU_DonationStatementConfirmationPS
     35 {
     36   /**
     37    * Purpose must be #DONAU_SIGNATURE_DONAU_DONATION_STATEMENT. Signed
     38    * by a `struct DONAU_DonauPublicKeyP` using EdDSA.
     39    */
     40   struct GNUNET_CRYPTO_SignaturePurpose purpose;
     41 
     42   /**
     43    * Total amount donated of a specific @a year.
     44    */
     45   struct TALER_AmountNBO amount_tot;
     46 
     47   /**
     48    * The hash of the identifier of the donor.
     49    */
     50   struct DONAU_HashDonorTaxId i;
     51 
     52   /**
     53    * The corresponding year.
     54    */
     55   uint32_t year;
     56 
     57 };
     58 
     59 GNUNET_NETWORK_STRUCT_END
     60 
     61 
     62 enum TALER_ErrorCode
     63 DONAU_donation_statement_sign (
     64   DONAU_DonauSignCallback scb,
     65   const struct TALER_Amount *amount_tot,
     66   const uint64_t year,
     67   const struct DONAU_HashDonorTaxId *i,
     68   struct DONAU_DonauPublicKeyP *donau_pub,
     69   struct DONAU_DonauSignatureP *donau_sig)
     70 {
     71   struct DONAU_DonationStatementConfirmationPS confirm = {
     72     .purpose.purpose = htonl (DONAU_SIGNATURE_DONAU_DONATION_STATEMENT),
     73     .purpose.size = htonl (sizeof (confirm)),
     74     .year = htonl (year),
     75     .i = *i
     76   };
     77 
     78   TALER_amount_hton (&confirm.amount_tot,
     79                      amount_tot);
     80 
     81   return scb (&confirm.purpose,
     82               donau_pub,
     83               donau_sig);
     84 }
     85 
     86 
     87 enum GNUNET_GenericReturnValue
     88 DONAU_donation_statement_verify (
     89   const struct TALER_Amount *amount_tot,
     90   const uint64_t year,
     91   const struct DONAU_HashDonorTaxId *i,
     92   const struct DONAU_DonauPublicKeyP *donau_pub,
     93   const struct DONAU_DonauSignatureP *statement_sig)
     94 {
     95   struct DONAU_DonationStatementConfirmationPS confirm = {
     96     .purpose.purpose = htonl (DONAU_SIGNATURE_DONAU_DONATION_STATEMENT),
     97     .purpose.size = htonl (sizeof (confirm)),
     98     .year = htonl (year),
     99     .i = *i
    100   };
    101 
    102   TALER_amount_hton (&confirm.amount_tot,
    103                      amount_tot);
    104 
    105   return
    106     GNUNET_CRYPTO_eddsa_verify (DONAU_SIGNATURE_DONAU_DONATION_STATEMENT,
    107                                 &confirm,
    108                                 &statement_sig->eddsa_sig,
    109                                 &donau_pub->eddsa_pub);
    110 }
    111 
    112 
    113 /* end of donau_signatures.c */