From 3eae999efc0cb923aebd2bf7214c5f4093217d4f Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Sun, 31 Oct 2021 17:56:56 +0100
Subject: distinguish between blind and non-blind denomination signatures

---
 src/util/crypto.c              | 16 ++++++++------
 src/util/crypto_helper_denom.c |  8 +++----
 src/util/denom.c               | 48 ++++++++++++++++++++++++++++++++++++------
 3 files changed, 54 insertions(+), 18 deletions(-)

(limited to 'src/util')

diff --git a/src/util/crypto.c b/src/util/crypto.c
index c7b459450..99744304b 100644
--- a/src/util/crypto.c
+++ b/src/util/crypto.c
@@ -212,21 +212,23 @@ TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk,
 
 
 enum GNUNET_GenericReturnValue
-TALER_planchet_to_coin (const struct TALER_DenominationPublicKey *dk,
-                        const struct GNUNET_CRYPTO_RsaSignature *blind_sig,
-                        const struct TALER_PlanchetSecretsP *ps,
-                        const struct TALER_CoinPubHash *c_hash,
-                        struct TALER_FreshCoin *coin)
+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 will be the bigger
+  // 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,
+    = TALER_rsa_unblind (blind_sig->details.blinded_rsa_signature,
                          &ps->blinding_key.bks,
                          dk->details.rsa_public_key);
   if (GNUNET_OK !=
diff --git a/src/util/crypto_helper_denom.c b/src/util/crypto_helper_denom.c
index ba56a4e71..4dfd32fbd 100644
--- a/src/util/crypto_helper_denom.c
+++ b/src/util/crypto_helper_denom.c
@@ -541,7 +541,7 @@ TALER_CRYPTO_helper_denom_poll (struct TALER_CRYPTO_DenominationHelper *dh)
 }
 
 
-struct TALER_DenominationSignature
+struct TALER_BlindedDenominationSignature
 TALER_CRYPTO_helper_denom_sign (
   struct TALER_CRYPTO_DenominationHelper *dh,
   const struct TALER_DenominationHash *h_denom_pub,
@@ -549,8 +549,8 @@ TALER_CRYPTO_helper_denom_sign (
   size_t msg_size,
   enum TALER_ErrorCode *ec)
 {
-  struct TALER_DenominationSignature ds = {
-    .details.rsa_signature = NULL
+  struct TALER_BlindedDenominationSignature ds = {
+    .details.blinded_rsa_signature = NULL
   };
   {
     char buf[sizeof (struct TALER_CRYPTO_SignRequest) + msg_size];
@@ -652,7 +652,7 @@ TALER_CRYPTO_helper_denom_sign (
         }
         *ec = TALER_EC_NONE;
         ds.cipher = TALER_DENOMINATION_RSA;
-        ds.details.rsa_signature = rsa_signature;
+        ds.details.blinded_rsa_signature = rsa_signature;
         return ds;
       }
     case TALER_HELPER_RSA_MT_RES_SIGN_FAILURE:
diff --git a/src/util/denom.c b/src/util/denom.c
index 33b507639..8d6ddd5e7 100644
--- a/src/util/denom.c
+++ b/src/util/denom.c
@@ -169,6 +169,27 @@ TALER_denom_sig_free (struct TALER_DenominationSignature *denom_sig)
 }
 
 
+void
+TALER_blinded_denom_sig_free (
+  struct TALER_BlindedDenominationSignature *denom_sig)
+{
+  switch (denom_sig->cipher)
+  {
+  case TALER_DENOMINATION_RSA:
+    if (NULL != denom_sig->details.blinded_rsa_signature)
+    {
+      GNUNET_CRYPTO_rsa_signature_free (
+        denom_sig->details.blinded_rsa_signature);
+      denom_sig->details.blinded_rsa_signature = NULL;
+    }
+    return;
+  // TODO: add case for Clause-Schnorr
+  default:
+    GNUNET_assert (0);
+  }
+}
+
+
 /**
  * Make a (deep) copy of the given @a denom_src to
  * @a denom_dst.
@@ -214,13 +235,26 @@ TALER_denom_sig_deep_copy (struct TALER_DenominationSignature *denom_dst,
 }
 
 
-/**
- * Compare two denomination public keys.
- *
- * @param denom1 first key
- * @param denom2 second key
- * @return 0 if the keys are equal, otherwise -1 or 1
- */
+void
+TALER_blinded_denom_sig_deep_copy (
+  struct TALER_BlindedDenominationSignature *denom_dst,
+  const struct TALER_BlindedDenominationSignature *denom_src)
+{
+  *denom_dst = *denom_src; /* shallow copy */
+  switch (denom_src->cipher)
+  {
+  case TALER_DENOMINATION_RSA:
+    denom_dst->details.blinded_rsa_signature
+      = GNUNET_CRYPTO_rsa_signature_dup (
+          denom_src->details.blinded_rsa_signature);
+    return;
+  // TODO: add case for Clause-Schnorr
+  default:
+    GNUNET_assert (0);
+  }
+}
+
+
 int
 TALER_denom_pub_cmp (const struct TALER_DenominationPublicKey *denom1,
                      const struct TALER_DenominationPublicKey *denom2)
-- 
cgit v1.2.3