added CS get R functionality and planchet setup

4 files changed, 117 insertions, 37 deletions

diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index 8e5df1fca..542146cc0 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -794,6 +794,9 @@ struct TALER_BlindedPlanchet
   } details;
 };
 
+/**
+ * Withdraw nonce for CS denominations
+ */
 struct TALER_WithdrawNonce
 {
   /**
@@ -802,6 +805,9 @@ struct TALER_WithdrawNonce
   struct GNUNET_CRYPTO_CsNonce nonce;
 };
 
+/**
+ * Withdraw nonce for CS denominations
+ */
 struct TALER_RefreshNonce
 {
   /**
@@ -811,6 +817,23 @@ struct TALER_RefreshNonce
 };
 
 /**
+ * Public R for Cs denominations
+ */
+struct TALER_DenominationCsPublicR
+{
+  struct GNUNET_CRYPTO_CsRPublic r_pub[2];
+};
+
+/**
+ * Secret r for Cs denominations
+ */
+
+struct TALER_DenominationCsPrivateR
+{
+  struct GNUNET_CRYPTO_CsRSecret r[2];
+};
+
+/**
  * @brief RSA Parameters to create blinded messages
  *
  */
@@ -863,28 +886,6 @@ struct TALER_DenominationBlindMessageParams
 };
 
 /**
- * @brief CS Blinding Secret parameters to derive blinding secrets
- *
- */
-struct TALER_PlanchetDeriveCsBlindingSecrets
-{
-  /**
-  * Secret to derive blinding secrets from
-  */
-  void *secret;
-
-  /**
-   * size of the secret to derive blinding secrets from
-   */
-  size_t secret_len;
-
-  /**
-   * public R_0 and R_1 are hashed too
-   */
-  struct GNUNET_CRYPTO_CsRPublic r_pub[2];
-};
-
-/**
  * @brief Public information about a coin (including the public key
  * of the coin, the denomination key and the signature with
  * the denomination key).
@@ -1013,6 +1014,36 @@ TALER_denom_sig_free (struct TALER_DenominationSignature *denom_sig);
 
 
 /**
+ * Function for CS signatures to derive the secret r_0 and r_1
+ *
+ * @param nonce withdraw nonce from a client
+ * @param denom_priv denomination privkey as long-term secret
+ * @param r the resulting r_0 and r_1
+ * @return enum GNUNET_GenericReturnValue, returns SYSERR when denom key has wrong type
+ */
+enum GNUNET_GenericReturnValue
+TALER_denom_cs_derive_r_secret (const struct TALER_WithdrawNonce *nonce,
+                                const struct
+                                TALER_DenominationPrivateKey *denom_priv,
+                                struct TALER_DenominationCsPrivateR *r);
+
+/**
+ * @brief Function for CS signatures to derive public R_0 and R_1
+ *
+ * @param nonce withdraw nonce from a client
+ * @param denom_priv denomination privkey as long-term secret
+ * @param r_pub the resulting R_0 and R_1
+ * @return enum GNUNET_GenericReturnValue
+ */
+
+enum GNUNET_GenericReturnValue
+TALER_denom_cs_derive_r_public (const struct TALER_WithdrawNonce *nonce,
+                                const struct
+                                TALER_DenominationPrivateKey *denom_priv,
+                                struct TALER_DenominationCsPublicR *r_pub);
+
+
+/**
  * Blind coin for blind signing with @a dk using blinding secret @a coin_bks.
  *
  * @param dk denomination public key to blind for
diff --git a/src/util/crypto.c b/src/util/crypto.c
index 40c69b54a..1ef0388dc 100644
--- a/src/util/crypto.c
+++ b/src/util/crypto.c
@@ -167,8 +167,8 @@ TALER_planchet_setup_refresh (const struct TALER_TransferSecretP *secret_seed,
 
 
 void
-cs_blinding_seed_derive (const void *secret,
-                         size_t secret_len,
+cs_blinding_seed_derive (const struct
+                         TALER_CoinSpendPrivateKeyP *coin_priv,
                          const struct GNUNET_CRYPTO_CsRPublic r_pub[2],
                          struct GNUNET_CRYPTO_CsNonce *blind_seed)
 {
@@ -179,8 +179,8 @@ cs_blinding_seed_derive (const void *secret,
                                      GCRY_MD_SHA256,
                                      "bseed",
                                      strlen ("bseed"),
-                                     secret,
-                                     secret_len,
+                                     coin_priv,
+                                     sizeof(*coin_priv),
                                      r_pub,
                                      sizeof(struct GNUNET_CRYPTO_CsRPublic) * 2,
                                      NULL,
@@ -227,11 +227,13 @@ TALER_blinding_secret_create (union TALER_DenominationBlindingKeyP *bs,
     return;
   case TALER_DENOMINATION_CS:
     {
-      struct TALER_PlanchetDeriveCsBlindingSecrets *params;
-      params = va_arg (ap, struct TALER_PlanchetDeriveCsBlindingSecrets *);
-      cs_blinding_seed_derive (params->secret,
-                               params->secret_len,
-                               params->r_pub,
+      struct TALER_CoinSpendPrivateKeyP *coin_priv;
+      struct TALER_DenominationCsPublicR *r_pub;
+      coin_priv = va_arg (ap, struct TALER_CoinSpendPrivateKeyP *);
+      r_pub = va_arg (ap, struct TALER_DenominationCsPublicR *);
+
+      cs_blinding_seed_derive (coin_priv,
+                               r_pub->r_pub,
                                &bs->nonce);
       return;
     }
diff --git a/src/util/denom.c b/src/util/denom.c
index 6ff92e894..6b587026e 100644
--- a/src/util/denom.c
+++ b/src/util/denom.c
@@ -82,6 +82,47 @@ TALER_denom_priv_create (struct TALER_DenominationPrivateKey *denom_priv,
 
 
 enum GNUNET_GenericReturnValue
+TALER_denom_cs_derive_r_secret (const struct TALER_WithdrawNonce *nonce,
+                                const struct
+                                TALER_DenominationPrivateKey *denom_priv,
+                                struct TALER_DenominationCsPrivateR *r)
+{
+  if (denom_priv->cipher != TALER_DENOMINATION_CS)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+
+  GNUNET_CRYPTO_cs_r_derive (&nonce->nonce,
+                             &denom_priv->details.cs_private_key,
+                             r->r);
+  return GNUNET_OK;
+}
+
+
+enum GNUNET_GenericReturnValue
+TALER_denom_cs_derive_r_public (const struct TALER_WithdrawNonce *nonce,
+                                const struct
+                                TALER_DenominationPrivateKey *denom_priv,
+                                struct TALER_DenominationCsPublicR *r_pub)
+{
+  if (denom_priv->cipher != TALER_DENOMINATION_CS)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+
+  struct GNUNET_CRYPTO_CsRSecret r[2];
+  GNUNET_CRYPTO_cs_r_derive (&nonce->nonce,
+                             &denom_priv->details.cs_private_key,
+                             r);
+  GNUNET_CRYPTO_cs_r_get_public (&r[0], &r_pub->r_pub[0]);
+  GNUNET_CRYPTO_cs_r_get_public (&r[1], &r_pub->r_pub[1]);
+  return GNUNET_OK;
+}
+
+
+enum GNUNET_GenericReturnValue
 TALER_denom_sign_blinded (struct TALER_BlindedDenominationSignature *denom_sig,
                           const struct TALER_DenominationPrivateKey *denom_priv,
                           const struct TALER_BlindedPlanchet *blinded_planchet)
diff --git a/src/util/test_crypto.c b/src/util/test_crypto.c
index a91536bf7..2fe70cda1 100644
--- a/src/util/test_crypto.c
+++ b/src/util/test_crypto.c
@@ -147,6 +147,8 @@ test_planchets_cs (void)
   struct TALER_PlanchetDetail pd;
   struct TALER_CoinPubHash c_hash;
   struct TALER_WithdrawNonce nonce;
+  struct TALER_DenominationCsPublicR r_pub;
+  // struct TALER_DenominationCsPrivateR priv_r;
   // struct TALER_BlindedDenominationSignature blind_sig;
   // struct TALER_FreshCoin coin;
   // struct TALER_PlanchetDeriveCsBlindingSecrets seed;
@@ -156,14 +158,18 @@ test_planchets_cs (void)
                                           &dk_pub,
                                           TALER_DENOMINATION_CS));
 
-  // seed.secret = "test secret";
-  // seed.secret_len = strlen ("test secret");
-
   TALER_planchet_setup_random (&ps, TALER_DENOMINATION_CS);
   TALER_cs_withdraw_nonce_derive (&ps.coin_priv, &nonce);
-
-  // NEXT: Implement to create withdraw nonce
-  // Implement to get R_0 and R_1
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_denom_cs_derive_r_public (&nonce,
+                                                 &dk_priv,
+                                                 &r_pub));
+  TALER_blinding_secret_create (&ps.blinding_key,
+                                TALER_DENOMINATION_CS,
+                                &ps.coin_priv,
+                                &r_pub);
+
+  // NEXT:
   // Implement to genrate b-seed from it and calculate c then§
 
   // GNUNET_assert (GNUNET_OK ==