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more denom key refactoring

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This commit is contained in:
Christian Grothoff 2021-11-05 14:18:13 +01:00
parent 32da809fd6
commit c787e28e84
No known key found for this signature in database
GPG Key ID: 939E6BE1E29FC3CC
3 changed files with 162 additions and 16 deletions
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61
src/include/taler_crypto_lib.h
View File

@ -587,6 +587,29 @@ struct TALER_DenominationPublicKey
};
/**
* Client-side secrets for blinding.
*/
struct TALER_BlindingSecret
{
/**
* Type of the blinding secret.
*/
enum TALER_DenominationCipher cipher;
union
{
/**
* Blinding key secret for RSA.
*/
struct GNUNET_CRYPTO_RsaBlindingKeySecret rsa_bks;
} details;
};
/**
* @brief Type of private signing keys for blind signing of coins.
*/
@ -677,6 +700,27 @@ void
TALER_denom_pub_free (struct TALER_DenominationPublicKey *denom_pub);
/**
* Create a blinding secret @a bs for @a cipher.
*
* @param[out] blinding secret to initialize
* @param cipher cipher to create blinding secret for
*/
enum GNUNET_GenericReturnValue
TALER_blinding_secret_create (struct TALER_BlindingSecret *bs,
enum TALER_DenominationCipher cipher,
...);
/**
* Release memory inside of a blinding secret @a bs.
*
* @param[in] blinding secret to free
*/
void
TALER_blinding_secret_free (struct TALER_BlindingSecret *bs);
/**
* Initialize denomination public-private key pair.
*
@ -731,6 +775,23 @@ TALER_denom_sign_blinded (struct TALER_BlindedDenominationSignature *denom_sig,
size_t blinded_msg_size);
/**
* Unblind blinded signature.
*
* @param[out] denom_sig where to write the unblinded signature
* @param bdenom_sig the blinded signature
* @param bks blinding secret to use
* @param denom_pub public key used for signing
* @return #GNUNET_OK on success
*/
enum GNUNET_GenericReturnValue
TALER_denom_sig_unblind (struct TALER_DenominationSignature *denom_sig,
const struct
TALER_BlindedDenominationSignature *bdenom_sig,
const struct TALER_BlindingSecret *bks,
const struct TALER_DenominationPublicKey *denom_pub);
/**
* Free internals of @a denom_sig, but not @a denom_sig itself.
*

88
src/util/denom.c
View File

@ -109,6 +109,94 @@ TALER_denom_sign_blinded (struct TALER_BlindedDenominationSignature *denom_sig,
}
enum GNUNET_GenericReturnValue
TALER_denom_sig_unblind (struct TALER_DenominationSignature *denom_sig,
const struct
TALER_BlindedDenominationSignature *bdenom_sig,
const struct TALER_BlindingSecret *bks,
const struct TALER_DenominationPublicKey *denom_pub)
{
if (bks->cipher != denom_pub->cipher)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (bdenom_sig->cipher != denom_pub->cipher)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
switch (denom_pub->cipher)
{
case TALER_DENOMINATION_INVALID:
GNUNET_break (0);
return GNUNET_SYSERR;
case TALER_DENOMINATION_RSA:
denom_sig->details.rsa_signature
= TALER_rsa_unblind (
bdenom_sig->details.blinded_rsa_signature,
&bks->details.rsa_bks,
denom_pub->details.rsa_public_key);
if (NULL == denom_sig->details.rsa_signature)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
denom_sig->cipher = TALER_DENOMINATION_RSA;
return GNUNET_OK;
// TODO: add case for Clause-Schnorr
default:
GNUNET_break (0);
}
return GNUNET_SYSERR;
}
enum GNUNET_GenericReturnValue
TALER_blinding_secret_create (struct TALER_BlindingSecret *bs,
enum TALER_DenominationCipher cipher,
...)
{
memset (bs,
0,
sizeof (*bs));
switch (bs->cipher)
{
case TALER_DENOMINATION_INVALID:
return GNUNET_OK;
case TALER_DENOMINATION_RSA:
bs->cipher = TALER_DENOMINATION_RSA;
GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
&bs->details.rsa_bks,
sizeof (bs->details.rsa_bks));
return GNUNET_OK;
// TODO: add case for Clause-Schnorr
default:
GNUNET_break (0);
}
return GNUNET_SYSERR;
}
void
TALER_blinding_secret_free (struct TALER_BlindingSecret *bs)
{
switch (bs->cipher)
{
case TALER_DENOMINATION_INVALID:
return;
case TALER_DENOMINATION_RSA:
memset (bs,
0,
sizeof (*bs));
return;
// TODO: add case for Clause-Schnorr
default:
GNUNET_break (0);
}
}
void
TALER_denom_pub_hash (const struct TALER_DenominationPublicKey *denom_pub,
struct TALER_DenominationHash *denom_hash)

29
src/util/test_helper_rsa.c
View File

@ -133,9 +133,7 @@ key_cb (void *cls,
{
keys[i].valid = false;
keys[i].revoked = false;
GNUNET_CRYPTO_rsa_public_key_free (
keys[i].denom_pub.details.rsa_public_key);
keys[i].denom_pub.details.rsa_public_key = NULL;
TALER_denom_pub_free (&keys[i].denom_pub);
GNUNET_assert (num_keys > 0);
num_keys--;
found = true;
@ -157,8 +155,8 @@ key_cb (void *cls,
keys[i].start_time = start_time;
keys[i].validity_duration = validity_duration;
keys[i].denom_pub = *denom_pub;
keys[i].denom_pub.details.rsa_public_key
= GNUNET_CRYPTO_rsa_public_key_dup (denom_pub->details.rsa_public_key);
TALER_denom_pub_deep_copy (&keys[i].denom_pub,
denom_pub);
num_keys++;
return;
}
@ -241,11 +239,11 @@ test_signing (struct TALER_CRYPTO_DenominationHelper *dh)
enum TALER_ErrorCode ec;
bool success = false;
struct TALER_CoinPubHash m_hash;
struct GNUNET_CRYPTO_RsaBlindingKeySecret bks;
struct TALER_BlindingSecret bks;
GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
&bks,
sizeof (bks));
GNUNET_assert (GNUNET_OK ==
TALER_blinding_secret_create (&bks,
TALER_DENOMINATION_RSA));
GNUNET_CRYPTO_hash ("Hello",
strlen ("Hello"),
&m_hash.hash);
@ -259,7 +257,7 @@ test_signing (struct TALER_CRYPTO_DenominationHelper *dh)
GNUNET_assert (GNUNET_YES ==
TALER_rsa_blind (&m_hash,
&bks,
&bks.details.rsa_bks,
keys[i].denom_pub.details.rsa_public_key,
&buf,
&buf_size));
@ -294,12 +292,11 @@ test_signing (struct TALER_CRYPTO_DenominationHelper *dh)
{
struct TALER_DenominationSignature rs;
rs.cipher = TALER_DENOMINATION_RSA;
rs.details.rsa_signature
= TALER_rsa_unblind (ds.details.blinded_rsa_signature,
&bks,
keys[i].denom_pub.details.rsa_public_key);
if (NULL == rs.details.rsa_signature)
if (GNUNET_OK !=
TALER_denom_sig_unblind (&rs,
&ds,
&bks,
&keys[i].denom_pub))
{
GNUNET_break (0);
return 6;