diff --git a/src/util/denom.c b/src/util/denom.c new file mode 100644 index 000000000..32c3469fc --- /dev/null +++ b/src/util/denom.c @@ -0,0 +1,115 @@ +/* + This file is part of TALER + Copyright (C) 2021 Taler Systems SA + + TALER is free software; you can redistribute it and/or modify it under the + terms of the GNU General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + TALER is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + A PARTICULAR PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along with + TALER; see the file COPYING. If not, see +*/ +/** + * @file denom.c + * @brief denomination utility functions + * @author Christian Grothoff + */ +#include "platform.h" +#include "taler_util.h" + + +void +TALER_denom_pub_hash (const struct TALER_DenominationPublicKey *denom_pub, + struct TALER_DenominationHash *denom_hash) +{ + uint32_t opt[2] = { + htonl (denom_pub->age_mask), + htonl ((uint32_t) denom_pub->cipher) + }; + + struct GNUNET_HashContext *hc; + hc = GNUNET_CRYPTO_hash_context_start (); + GNUNET_CRYPTO_hash_context_read (hc, + opt, + sizeof (opt)); + switch (denom_pub->cipher) + { + case TALER_DENOMINATION_RSA: + { + void *buf; + size_t blen; + + blen = GNUNET_CRYPTO_rsa_public_key_encode ( + denom_pub->details.rsa_public_key, + &buf); + GNUNET_CRYPTO_hash_context_read (hc, + buf, + blen); + GNUNET_free (buf); + } + break; + // TODO: add case for Clause-Schnorr + default: + GNUNET_assert (0); + } + GNUNET_CRYPTO_hash_context_finish (hc, + &denom_hash->hash); +} + + +void +TALER_denom_priv_to_pub (const struct TALER_DenominationPrivateKey *denom_priv, + uint32_t age_mask, + struct TALER_DenominationPublicKey *denom_pub) +{ + switch (denom_priv->cipher) + { + case TALER_DENOMINATION_RSA: + denom_pub->cipher = TALER_DENOMINATION_RSA; + denom_pub->age_mask = age_mask; + denom_pub->details.rsa_public_key + = GNUNET_CRYPTO_rsa_private_key_get_public ( + denom_priv->details.rsa_private_key); + return; + // TODO: add case for Clause-Schnorr + default: + GNUNET_assert (0); + } +} + + +enum GNUNET_GenericReturnValue +TALER_denom_pub_verify (const struct TALER_DenominationPublicKey *denom_pub, + const struct TALER_DenominationSignature *denom_sig, + const struct TALER_CoinPubHash *c_hash) +{ + if (denom_pub->cipher != denom_sig->cipher) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + switch (denom_pub->cipher) + { + case TALER_DENOMINATION_RSA: + if (GNUNET_OK != + GNUNET_CRYPTO_rsa_verify (&c_hash->hash, + denom_sig->details.rsa_signature, + denom_pub->details.rsa_public_key)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + "Coin signature is invalid\n"); + return GNUNET_NO; + } + return GNUNET_YES; + // TODO: add case for Clause-Schnorr + default: + GNUNET_assert (0); + } +} + + +/* end of denom.c */