donau

commit 37af64260f7011e640daa52009510250254812a2
parent b31b93eda7e62079894c9d65758068fe3d6a8c32
Author: Matyja Lukas Adam <lukas.matyja@students.bfh.ch>
Date:   Wed, 20 Mar 2024 00:44:57 +0100

[util] create blind sign function

Diffstat:
M
src/include/donau_crypto_lib.h
 | 
51
++++++++++++++++++++++++++++++++++++++++++++++++++-
M
src/util/donau_signatures.c
 | 
14
++++++++++++++

2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/src/include/donau_crypto_lib.h b/src/include/donau_crypto_lib.h
@@ -202,6 +202,18 @@ struct DONAU_BlindedDonationUnitSignature
 
 
 /**
+ * @brief Type of (unblinded) donation receipts signatures for Taler.
+ */
+struct DONAU_DonationUnitSignature
+{
+  /**
+   * Denominations use blind signatures.
+   */
+  struct GNUNET_CRYPTO_UnblindedSignature *unblinded_sig;
+};
+
+
+/**
  * @brief Type of signature used by the donau for non-blind signatures.
  */
 struct DONAU_DonauSignatureP
@@ -242,7 +254,7 @@ struct DONAU_BlindedUniqueDonationIdentifier
   /*
   * GNUNET primitive type representing a generic blinded message
   */
-  struct GNUNET_CRYPTO_BlindedMessage blinded_message;
+  struct GNUNET_CRYPTO_BlindedMessage *blinded_message;
 };
 
 /**
@@ -272,6 +284,14 @@ struct DONAU_BudiKeyPairsHashP
   struct GNUNET_HashCode hash;
 };
 
+/**
+ * Hash of a budikeypair array
+ */
+struct DONAU_BudiHashP
+{
+  struct GNUNET_HashCode hash;
+};
+
 
 /* ********************* charity eddsa signing ************************** */
 
@@ -364,6 +384,35 @@ void
 DONAU_blinded_donation_unit_sig_free (
   struct DONAU_BlindedDonationUnitSignature *donation_unit_sig);
 
+/**
+ * Create blinded signature.
+ *
+ * @param[out] du_sig where to write the signature
+ * @param du_priv private key to use for signing
+ * @param budi the unique identifier already blinded
+ * @return #GNUNET_OK on success
+ */
+enum GNUNET_GenericReturnValue
+TALER_donation_unit_sign_blinded (struct DONAU_BlindedDonationUnitSignature *du_sig,
+                          const struct DONAU_DonationUnitPrivateKey *du_priv,
+                          const struct DONAU_BlindedUniqueDonationIdentifier *budi);
+
+
+/**
+ * Verify signature made with a donation unit public key
+ * over a budi.
+ *
+ * @param du_pub public donation unit key
+ * @param du_sig signature made with the private key
+ * @param budi_hash hash over the budi
+ * @return #GNUNET_OK if the signature is valid
+ */
+enum GNUNET_GenericReturnValue
+TALER_donation_unit_pub_verify (const struct DONAU_DonationUnitPublicKey *du_pub,
+                        const struct DONAU_DonationUnitSignature *du_sig,
+                        const struct DONAU_BudiHashP *budi_hash);
+
+
 // FIXME: Copied from taler_crypto_lib.h, is anything of this necessary?
 ///**
 // * Compute the hash of the given @a donation_unit_pub.
diff --git a/src/util/donau_signatures.c b/src/util/donau_signatures.c
@@ -111,4 +111,18 @@ DONAU_donation_statement_verify (
 }
 
 
+enum GNUNET_GenericReturnValue
+TALER_donation_unit_sign_blinded (struct DONAU_BlindedDonationUnitSignature *du_sig,
+                          const struct DONAU_DonationUnitPrivateKey *du_priv,
+                          const struct DONAU_BlindedUniqueDonationIdentifier *budi)
+{
+  du_sig->blinded_sig
+    = GNUNET_CRYPTO_blind_sign (du_priv->bsign_priv_key,
+                                /*for_melt ? "rm" :*/ "rw",
+                                budi->blinded_message);
+  if (NULL == du_sig->blinded_sig)
+    return GNUNET_SYSERR;
+  return GNUNET_OK;
+}
+
 /* end of donau_signatures.c */