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add sign and verify implementation

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This commit is contained in:
Gian Demarmels 2021-12-23 12:36:04 +01:00
parent 5d2157a8f6
commit db9b84970d
No known key found for this signature in database
GPG Key ID: 030CEDDCCC92D778
4 changed files with 97 additions and 19 deletions
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6
src/include/taler_crypto_lib.h
View File

@ -1095,7 +1095,8 @@ TALER_denom_sig_unblind (
struct TALER_DenominationSignature *denom_sig,
const struct TALER_BlindedDenominationSignature *bdenom_sig,
const union TALER_DenominationBlindingKeyP *bks,
const struct TALER_DenominationPublicKey *denom_pub);
const struct TALER_DenominationPublicKey *denom_pub,
...);
/**
@ -1492,7 +1493,8 @@ TALER_planchet_to_coin (
const struct TALER_BlindedDenominationSignature *blind_sig,
const struct TALER_PlanchetSecretsP *ps,
const struct TALER_CoinPubHash *c_hash,
struct TALER_FreshCoin *coin);
struct TALER_FreshCoin *coin,
...);
/* ****************** Refresh crypto primitives ************* */

50
src/util/crypto.c
View File

@ -309,9 +309,11 @@ TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk,
va_start (ap, pd);
struct TALER_WithdrawNonce *nonce;
struct TALER_DenominationCsPublicR *r_pub;
struct TALER_DenominationCsPublicR *blinded_r_pub;
nonce = va_arg (ap, struct TALER_WithdrawNonce *);
r_pub = va_arg (ap, struct TALER_DenominationCsPublicR *);
blinded_r_pub = va_arg (ap, struct TALER_DenominationCsPublicR *);
if (GNUNET_OK !=
TALER_denom_blind (dk,
@ -321,7 +323,8 @@ TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk,
c_hash,
&pd->blinded_planchet,
nonce,
r_pub))
r_pub,
blinded_r_pub))
{
va_end (ap);
GNUNET_break (0);
@ -347,19 +350,50 @@ TALER_planchet_to_coin (
const struct TALER_BlindedDenominationSignature *blind_sig,
const struct TALER_PlanchetSecretsP *ps,
const struct TALER_CoinPubHash *c_hash,
struct TALER_FreshCoin *coin)
struct TALER_FreshCoin *coin,
...)
{
struct TALER_DenominationSignature sig;
if (GNUNET_OK !=
TALER_denom_sig_unblind (&sig,
blind_sig,
&ps->blinding_key,
dk))
switch (dk->cipher)
{
GNUNET_break_op (0);
case TALER_DENOMINATION_RSA:
if (GNUNET_OK !=
TALER_denom_sig_unblind (&sig,
blind_sig,
&ps->blinding_key,
dk))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
break;
case TALER_DENOMINATION_CS:
{
va_list ap;
va_start (ap, coin);
struct TALER_DenominationCsPublicR *r_pub_dash;
r_pub_dash = va_arg (ap, struct TALER_DenominationCsPublicR *);
if (GNUNET_OK !=
TALER_denom_sig_unblind (&sig,
blind_sig,
&ps->blinding_key,
dk,
r_pub_dash))
{
GNUNET_break_op (0);
va_end (ap);
return GNUNET_SYSERR;
}
va_end (ap);
}
break;
default:
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_denom_pub_verify (dk,
&sig,

54
src/util/denom.c
View File

@ -186,7 +186,8 @@ TALER_denom_sig_unblind (
struct TALER_DenominationSignature *denom_sig,
const struct TALER_BlindedDenominationSignature *bdenom_sig,
const union TALER_DenominationBlindingKeyP *bks,
const struct TALER_DenominationPublicKey *denom_pub)
const struct TALER_DenominationPublicKey *denom_pub,
...)
{
if (bdenom_sig->cipher != denom_pub->cipher)
{
@ -211,7 +212,36 @@ TALER_denom_sig_unblind (
}
denom_sig->cipher = TALER_DENOMINATION_RSA;
return GNUNET_OK;
// TODO: add case for Clause-Schnorr
case TALER_DENOMINATION_CS:
{
va_list ap;
va_start (ap, denom_pub);
struct TALER_DenominationCsPublicR *r_pub_dash;
r_pub_dash = va_arg (ap, struct TALER_DenominationCsPublicR *);
struct GNUNET_CRYPTO_CsBlindingSecret bs[2];
GNUNET_CRYPTO_cs_blinding_secrets_derive (&bks->nonce, bs);
struct GNUNET_CRYPTO_CsS s_scalar;
GNUNET_CRYPTO_cs_unblind (&bdenom_sig->details.blinded_cs_answer.s_scalar,
&bs[bdenom_sig->details.blinded_cs_answer.b],
&s_scalar);
// TODO: This seems to work, but is this a good idea?
// Not working:
// denom_sig->details.cs_signature.r_point = r_pub_dash->r_pub[bdenom_sig->details.blinded_cs_answer.b];
GNUNET_memcpy (&denom_sig->details.cs_signature, &s_scalar, sizeof(struct
GNUNET_CRYPTO_CsS));
GNUNET_memcpy (&denom_sig->details.cs_signature + sizeof(struct
GNUNET_CRYPTO_CsS),
&r_pub_dash->r_pub[bdenom_sig->details.blinded_cs_answer.b],
sizeof(struct GNUNET_CRYPTO_CsRPublic));
denom_sig->cipher = TALER_DENOMINATION_CS;
va_end (ap);
return GNUNET_OK;
}
default:
GNUNET_break (0);
}
@ -330,16 +360,15 @@ TALER_denom_blind (const struct TALER_DenominationPublicKey *dk,
return GNUNET_OK;
case TALER_DENOMINATION_CS:
{
// TODO: Where to store the blinded rpub? currently ignored
struct GNUNET_CRYPTO_CsRPublic blinded_r_pub[2];
va_list ap;
va_start (ap, blinded_planchet);
struct TALER_WithdrawNonce *nonce;
struct TALER_DenominationCsPublicR *r_pub;
struct TALER_DenominationCsPublicR *blinded_r_pub;
nonce = va_arg (ap, struct TALER_WithdrawNonce *);
r_pub = va_arg (ap, struct TALER_DenominationCsPublicR *);
blinded_r_pub = va_arg (ap, struct TALER_DenominationCsPublicR *);
struct GNUNET_CRYPTO_CsBlindingSecret bs[2];
GNUNET_CRYPTO_cs_blinding_secrets_derive (&nonce->nonce, bs);
@ -351,7 +380,7 @@ TALER_denom_blind (const struct TALER_DenominationPublicKey *dk,
sizeof(struct GNUNET_HashCode),
blinded_planchet->details.
cs_blinded_planchet.c,
blinded_r_pub);
blinded_r_pub->r_pub);
va_end (ap);
return GNUNET_OK;
@ -389,7 +418,18 @@ TALER_denom_pub_verify (const struct TALER_DenominationPublicKey *denom_pub,
return GNUNET_NO;
}
return GNUNET_YES;
// TODO: add case for Clause-Schnorr
case TALER_DENOMINATION_CS:
if (GNUNET_OK !=
GNUNET_CRYPTO_cs_verify (&denom_sig->details.cs_signature,
&denom_pub->details.cs_public_key,
c_hash,
sizeof(*c_hash)))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Coin signature is invalid\n");
return GNUNET_NO;
}
return GNUNET_YES;
default:
GNUNET_assert (0);
}

6
src/util/test_crypto.c
View File

@ -175,7 +175,8 @@ test_planchets_cs (void)
&c_hash,
&pd,
&nonce,
&r_pub));
&r_pub,
&r_pub_blind));
// TODO: Remove r_secret if not needed
GNUNET_assert (GNUNET_OK ==
TALER_denom_cs_derive_r_secret (&nonce,
@ -192,7 +193,8 @@ test_planchets_cs (void)
// &blind_sig,
// &ps,
// &c_hash,
// &coin));
// &coin,
// &r_pub_blind));
TALER_blinded_denom_sig_free (&blind_sig);
// TALER_denom_sig_free (&coin.sig);