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/*
This file is part of GNUnet.
Copyright (C) 2018 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet 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
Affero General Public License for more details.
*/
/**
* @file util/crypto_bug.c
* @brief work around unidentified public key cryptography bug
* @author Christian Grothoff
*/
/**
* Enable work-around. Will cause code to call #check_eddsa_key() to
* see if we have a bad key, and if so, create a new one.
*/
#define CRYPTO_BUG 0
#if CRYPTO_BUG
/**
* Check if ECDH works with @a priv_dsa and this version
* of libgcrypt.
*
* @param priv_dsa key to check
* @return #GNUNET_OK if key passes
*/
static int
check_eddsa_key (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv_dsa)
{
struct GNUNET_CRYPTO_EcdhePrivateKey *priv_ecdh;
struct GNUNET_CRYPTO_EddsaPublicKey id1;
struct GNUNET_CRYPTO_EcdhePublicKey id2;
struct GNUNET_HashCode dh[2];
GNUNET_CRYPTO_eddsa_key_get_public (priv_dsa,
&id1);
for (unsigned int j=0;j<4;j++)
{
priv_ecdh = GNUNET_CRYPTO_ecdhe_key_create ();
/* Extract public keys */
GNUNET_CRYPTO_ecdhe_key_get_public (priv_ecdh,
&id2);
/* Do ECDH */
GNUNET_assert (GNUNET_OK ==
GNUNET_CRYPTO_eddsa_ecdh (priv_dsa,
&id2,
&dh[0]));
GNUNET_assert (GNUNET_OK ==
GNUNET_CRYPTO_ecdh_eddsa (priv_ecdh,
&id1,
&dh[1]));
/* Check that both DH results are equal. */
if (0 != memcmp (&dh[0],
&dh[1],
sizeof (struct GNUNET_HashCode)))
{
GNUNET_break (0); /* bad EdDSA key! */
return GNUNET_SYSERR;
}
GNUNET_free (priv_ecdh);
}
return GNUNET_OK;
}
#endif
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