366 lines
12 KiB
C
366 lines
12 KiB
C
/*
|
|
This file is part of TALER
|
|
Copyright (C) 2014-2017 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 <http://www.gnu.org/licenses/>
|
|
*/
|
|
/**
|
|
* @file util/crypto.c
|
|
* @brief Cryptographic utility functions
|
|
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
|
|
* @author Florian Dold
|
|
* @author Benedikt Mueller
|
|
* @author Christian Grothoff
|
|
*/
|
|
#include "platform.h"
|
|
#include "taler_util.h"
|
|
#include <gcrypt.h>
|
|
|
|
|
|
/**
|
|
* Function called by libgcrypt on serious errors.
|
|
* Prints an error message and aborts the process.
|
|
*
|
|
* @param cls NULL
|
|
* @param wtf unknown
|
|
* @param msg error message
|
|
*/
|
|
static void
|
|
fatal_error_handler (void *cls,
|
|
int wtf,
|
|
const char *msg)
|
|
{
|
|
(void) cls;
|
|
(void) wtf;
|
|
fprintf (stderr,
|
|
"Fatal error in libgcrypt: %s\n",
|
|
msg);
|
|
abort ();
|
|
}
|
|
|
|
|
|
/**
|
|
* Initialize libgcrypt.
|
|
*/
|
|
void __attribute__ ((constructor))
|
|
TALER_gcrypt_init ()
|
|
{
|
|
gcry_set_fatalerror_handler (&fatal_error_handler,
|
|
NULL);
|
|
if (! gcry_check_version (NEED_LIBGCRYPT_VERSION))
|
|
{
|
|
fprintf (stderr,
|
|
"libgcrypt version mismatch\n");
|
|
abort ();
|
|
}
|
|
/* Disable secure memory (we should never run on a system that
|
|
even uses swap space for memory). */
|
|
gcry_control (GCRYCTL_DISABLE_SECMEM, 0);
|
|
gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
|
|
}
|
|
|
|
|
|
enum GNUNET_GenericReturnValue
|
|
TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info,
|
|
const struct TALER_DenominationPublicKey *denom_pub)
|
|
{
|
|
struct TALER_CoinPubHash c_hash;
|
|
#if ENABLE_SANITY_CHECKS
|
|
struct TALER_DenominationHash d_hash;
|
|
|
|
TALER_denom_pub_hash (denom_pub,
|
|
&d_hash);
|
|
GNUNET_assert (0 ==
|
|
GNUNET_memcmp (&d_hash,
|
|
&coin_public_info->denom_pub_hash));
|
|
#endif
|
|
// FIXME-Oec: replace with function that
|
|
// also hashes the age vector if we have
|
|
// one!
|
|
GNUNET_CRYPTO_hash (&coin_public_info->coin_pub,
|
|
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
|
|
&c_hash.hash);
|
|
if (GNUNET_OK !=
|
|
TALER_denom_pub_verify (denom_pub,
|
|
&coin_public_info->denom_sig,
|
|
&c_hash))
|
|
{
|
|
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
|
|
"coin signature is invalid\n");
|
|
return GNUNET_NO;
|
|
}
|
|
return GNUNET_YES;
|
|
}
|
|
|
|
|
|
void
|
|
TALER_link_derive_transfer_secret (
|
|
const struct TALER_CoinSpendPrivateKeyP *coin_priv,
|
|
const struct TALER_TransferPrivateKeyP *trans_priv,
|
|
struct TALER_TransferSecretP *ts)
|
|
{
|
|
struct TALER_CoinSpendPublicKeyP coin_pub;
|
|
|
|
GNUNET_CRYPTO_eddsa_key_get_public (&coin_priv->eddsa_priv,
|
|
&coin_pub.eddsa_pub);
|
|
GNUNET_assert (GNUNET_OK ==
|
|
GNUNET_CRYPTO_ecdh_eddsa (&trans_priv->ecdhe_priv,
|
|
&coin_pub.eddsa_pub,
|
|
&ts->key));
|
|
|
|
}
|
|
|
|
|
|
void
|
|
TALER_link_reveal_transfer_secret (
|
|
const struct TALER_TransferPrivateKeyP *trans_priv,
|
|
const struct TALER_CoinSpendPublicKeyP *coin_pub,
|
|
struct TALER_TransferSecretP *transfer_secret)
|
|
{
|
|
GNUNET_assert (GNUNET_OK ==
|
|
GNUNET_CRYPTO_ecdh_eddsa (&trans_priv->ecdhe_priv,
|
|
&coin_pub->eddsa_pub,
|
|
&transfer_secret->key));
|
|
}
|
|
|
|
|
|
void
|
|
TALER_link_recover_transfer_secret (
|
|
const struct TALER_TransferPublicKeyP *trans_pub,
|
|
const struct TALER_CoinSpendPrivateKeyP *coin_priv,
|
|
struct TALER_TransferSecretP *transfer_secret)
|
|
{
|
|
GNUNET_assert (GNUNET_OK ==
|
|
GNUNET_CRYPTO_eddsa_ecdh (&coin_priv->eddsa_priv,
|
|
&trans_pub->ecdhe_pub,
|
|
&transfer_secret->key));
|
|
}
|
|
|
|
|
|
void
|
|
TALER_planchet_setup_refresh (const struct TALER_TransferSecretP *secret_seed,
|
|
uint32_t coin_num_salt,
|
|
struct TALER_PlanchetSecretsP *ps)
|
|
{
|
|
uint32_t be_salt = htonl (coin_num_salt);
|
|
|
|
GNUNET_assert (GNUNET_OK ==
|
|
GNUNET_CRYPTO_kdf (ps,
|
|
sizeof (*ps),
|
|
&be_salt,
|
|
sizeof (be_salt),
|
|
secret_seed,
|
|
sizeof (*secret_seed),
|
|
"taler-coin-derivation",
|
|
strlen ("taler-coin-derivation"),
|
|
NULL, 0));
|
|
}
|
|
|
|
|
|
void
|
|
TALER_planchet_setup_random (struct TALER_PlanchetSecretsP *ps)
|
|
{
|
|
GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
|
|
ps,
|
|
sizeof (*ps));
|
|
}
|
|
|
|
|
|
enum GNUNET_GenericReturnValue
|
|
TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk,
|
|
const struct TALER_PlanchetSecretsP *ps,
|
|
struct TALER_CoinPubHash *c_hash,
|
|
struct TALER_PlanchetDetail *pd)
|
|
{
|
|
struct TALER_CoinSpendPublicKeyP coin_pub;
|
|
|
|
GNUNET_CRYPTO_eddsa_key_get_public (&ps->coin_priv.eddsa_priv,
|
|
&coin_pub.eddsa_pub);
|
|
// FIXME-Oec: replace with function that
|
|
// also hashes the age vector if we have
|
|
// one!
|
|
GNUNET_CRYPTO_hash (&coin_pub.eddsa_pub,
|
|
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
|
|
&c_hash->hash);
|
|
// FIXME-Gian/Lucien: this will be the bigger
|
|
// change, as you have the extra round trip
|
|
// => to be discussed!
|
|
GNUNET_assert (TALER_DENOMINATION_RSA == dk->cipher);
|
|
if (GNUNET_YES !=
|
|
TALER_rsa_blind (c_hash,
|
|
&ps->blinding_key.bks,
|
|
dk->details.rsa_public_key,
|
|
&pd->coin_ev,
|
|
&pd->coin_ev_size))
|
|
{
|
|
GNUNET_break_op (0);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
TALER_denom_pub_hash (dk,
|
|
&pd->denom_pub_hash);
|
|
return GNUNET_OK;
|
|
}
|
|
|
|
|
|
enum GNUNET_GenericReturnValue
|
|
TALER_planchet_to_coin (
|
|
const struct TALER_DenominationPublicKey *dk,
|
|
const struct TALER_BlindedDenominationSignature *blind_sig,
|
|
const struct TALER_PlanchetSecretsP *ps,
|
|
const struct TALER_CoinPubHash *c_hash,
|
|
struct TALER_FreshCoin *coin)
|
|
{
|
|
struct TALER_DenominationSignature sig;
|
|
|
|
// FIXME-Gian/Lucien: this may need a bigger
|
|
// change, as you have the extra round trip
|
|
// => to be discussed!
|
|
GNUNET_assert (TALER_DENOMINATION_RSA == dk->cipher);
|
|
GNUNET_assert (TALER_DENOMINATION_RSA == blind_sig->cipher);
|
|
sig.cipher = TALER_DENOMINATION_RSA;
|
|
sig.details.rsa_signature
|
|
= TALER_rsa_unblind (blind_sig->details.blinded_rsa_signature,
|
|
&ps->blinding_key.bks,
|
|
dk->details.rsa_public_key);
|
|
if (GNUNET_OK !=
|
|
TALER_denom_pub_verify (dk,
|
|
&sig,
|
|
c_hash))
|
|
{
|
|
GNUNET_break_op (0);
|
|
GNUNET_CRYPTO_rsa_signature_free (sig.details.rsa_signature);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
coin->sig = sig;
|
|
coin->coin_priv = ps->coin_priv;
|
|
return GNUNET_OK;
|
|
}
|
|
|
|
|
|
void
|
|
TALER_refresh_get_commitment (struct TALER_RefreshCommitmentP *rc,
|
|
uint32_t kappa,
|
|
uint32_t num_new_coins,
|
|
const struct TALER_RefreshCommitmentEntry *rcs,
|
|
const struct TALER_CoinSpendPublicKeyP *coin_pub,
|
|
const struct TALER_Amount *amount_with_fee)
|
|
{
|
|
struct GNUNET_HashContext *hash_context;
|
|
|
|
hash_context = GNUNET_CRYPTO_hash_context_start ();
|
|
/* first, iterate over transfer public keys for hash_context */
|
|
for (unsigned int i = 0; i<kappa; i++)
|
|
{
|
|
GNUNET_CRYPTO_hash_context_read (hash_context,
|
|
&rcs[i].transfer_pub,
|
|
sizeof (struct TALER_TransferPublicKeyP));
|
|
}
|
|
/* next, add all of the hashes from the denomination keys to the
|
|
hash_context */
|
|
for (unsigned int i = 0; i<num_new_coins; i++)
|
|
{
|
|
struct TALER_DenominationHash denom_hash;
|
|
|
|
/* The denomination keys should / must all be identical regardless
|
|
of what offset we use, so we use [0]. */
|
|
GNUNET_assert (kappa > 0); /* sanity check */
|
|
TALER_denom_pub_hash (rcs[0].new_coins[i].dk,
|
|
&denom_hash);
|
|
GNUNET_CRYPTO_hash_context_read (hash_context,
|
|
&denom_hash,
|
|
sizeof (denom_hash));
|
|
}
|
|
|
|
/* next, add public key of coin and amount being refreshed */
|
|
{
|
|
struct TALER_AmountNBO melt_amountn;
|
|
|
|
GNUNET_CRYPTO_hash_context_read (hash_context,
|
|
coin_pub,
|
|
sizeof (struct TALER_CoinSpendPublicKeyP));
|
|
TALER_amount_hton (&melt_amountn,
|
|
amount_with_fee);
|
|
GNUNET_CRYPTO_hash_context_read (hash_context,
|
|
&melt_amountn,
|
|
sizeof (struct TALER_AmountNBO));
|
|
}
|
|
|
|
/* finally, add all the envelopes */
|
|
for (unsigned int i = 0; i<kappa; i++)
|
|
{
|
|
const struct TALER_RefreshCommitmentEntry *rce = &rcs[i];
|
|
|
|
for (unsigned int j = 0; j<num_new_coins; j++)
|
|
{
|
|
const struct TALER_RefreshCoinData *rcd = &rce->new_coins[j];
|
|
|
|
GNUNET_CRYPTO_hash_context_read (hash_context,
|
|
rcd->coin_ev,
|
|
rcd->coin_ev_size);
|
|
}
|
|
}
|
|
|
|
/* Conclude */
|
|
GNUNET_CRYPTO_hash_context_finish (hash_context,
|
|
&rc->session_hash);
|
|
}
|
|
|
|
|
|
enum GNUNET_GenericReturnValue
|
|
TALER_rsa_blind (const struct TALER_CoinPubHash *hash,
|
|
const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
|
|
struct GNUNET_CRYPTO_RsaPublicKey *pkey,
|
|
void **buf,
|
|
size_t *buf_size)
|
|
{
|
|
return GNUNET_CRYPTO_rsa_blind (&hash->hash,
|
|
bks,
|
|
pkey,
|
|
buf,
|
|
buf_size);
|
|
}
|
|
|
|
|
|
struct GNUNET_CRYPTO_RsaSignature *
|
|
TALER_rsa_unblind (const struct GNUNET_CRYPTO_RsaSignature *sig,
|
|
const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
|
|
struct GNUNET_CRYPTO_RsaPublicKey *pkey)
|
|
{
|
|
return GNUNET_CRYPTO_rsa_unblind (sig,
|
|
bks,
|
|
pkey);
|
|
}
|
|
|
|
|
|
void
|
|
TALER_coin_ev_hash (const void *coin_ev,
|
|
size_t coin_ev_size,
|
|
struct TALER_BlindedCoinHash *bch)
|
|
{
|
|
GNUNET_CRYPTO_hash (coin_ev,
|
|
coin_ev_size,
|
|
&bch->hash);
|
|
}
|
|
|
|
|
|
void
|
|
TALER_coin_pub_hash (const struct TALER_CoinSpendPublicKeyP *coin_pub,
|
|
struct TALER_CoinPubHash *coin_h)
|
|
{
|
|
GNUNET_CRYPTO_hash (&coin_pub->eddsa_pub,
|
|
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
|
|
&coin_h->hash);
|
|
}
|
|
|
|
|
|
/* end of crypto.c */
|