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/include/taler_crypto_lib.h        | 64 +++++++++++++++++++++++++++++++----
 src/include/taler_exchange_service.h  |  2 +-
 src/include/taler_exchangedb_plugin.h |  6 ++--
 src/include/taler_json_lib.h          | 29 ++++++++++++++++
 src/include/taler_pq_lib.h            | 25 ++++++++++++++
 5 files changed, 116 insertions(+), 10 deletions(-)

(limited to 'src/include')

diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index af567ba02..69acfa0b3 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -523,6 +523,34 @@ struct TALER_DenominationSignature
 };
 
 
+/**
+ * @brief Type for *blinded* denomination signatures for Taler.
+ * Must be unblinded before it becomes valid.
+ */
+struct TALER_BlindedDenominationSignature
+{
+
+  /**
+   * Type of the signature.
+   */
+  enum TALER_DenominationCipher cipher;
+
+  /**
+   * Details, depending on @e cipher.
+   */
+  union
+  {
+
+    /**
+     * If we use #TALER_DENOMINATION_RSA in @a cipher.
+     */
+    struct GNUNET_CRYPTO_RsaSignature *blinded_rsa_signature;
+
+  } details;
+
+};
+
+
 /**
  * @brief Type of public signing keys for verifying blindly signed coins.
  */
@@ -662,6 +690,16 @@ void
 TALER_denom_sig_free (struct TALER_DenominationSignature *denom_sig);
 
 
+/**
+ * Free internals of @a denom_sig, but not @a denom_sig itself.
+ *
+ * @param[in] denom_sig signature to free
+ */
+void
+TALER_blinded_denom_sig_free (
+  struct TALER_BlindedDenominationSignature *denom_sig);
+
+
 /**
  * Compute the hash of the given @a denom_pub.
  *
@@ -697,6 +735,19 @@ TALER_denom_sig_deep_copy (struct TALER_DenominationSignature *denom_dst,
                            const struct TALER_DenominationSignature *denom_src);
 
 
+/**
+ * Make a (deep) copy of the given @a denom_src to
+ * @a denom_dst.
+ *
+ * @param[out] denom_dst target to copy to
+ * @param denom_str public key to copy
+ */
+void
+TALER_blinded_denom_sig_deep_copy (
+  struct TALER_BlindedDenominationSignature *denom_dst,
+  const struct TALER_BlindedDenominationSignature *denom_src);
+
+
 /**
  * Compare two denomination public keys.
  *
@@ -1014,11 +1065,12 @@ TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk,
  * @return #GNUNET_OK on success
  */
 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);
 
 
 /* ****************** Refresh crypto primitives ************* */
@@ -1215,7 +1267,7 @@ TALER_CRYPTO_helper_denom_poll (struct TALER_CRYPTO_DenominationHelper *dh);
  * @return signature, the value inside the structure will be NULL on failure,
  *         see @a ec for details about the failure
  */
-struct TALER_DenominationSignature
+struct TALER_BlindedDenominationSignature
 TALER_CRYPTO_helper_denom_sign (
   struct TALER_CRYPTO_DenominationHelper *dh,
   const struct TALER_DenominationHash *h_denom_pub,
diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index 6daa120d4..361956cbe 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -1387,7 +1387,7 @@ typedef void
 (*TALER_EXCHANGE_Withdraw2Callback) (
   void *cls,
   const struct TALER_EXCHANGE_HttpResponse *hr,
-  const struct GNUNET_CRYPTO_RsaSignature *blind_sig);
+  const struct TALER_BlindedDenominationSignature *blind_sig);
 
 
 /**
diff --git a/src/include/taler_exchangedb_plugin.h b/src/include/taler_exchangedb_plugin.h
index aa67092ee..17df75281 100644
--- a/src/include/taler_exchangedb_plugin.h
+++ b/src/include/taler_exchangedb_plugin.h
@@ -696,9 +696,9 @@ struct TALER_EXCHANGEDB_CollectableBlindcoin
 {
 
   /**
-   * Our signature over the (blinded) coin.
+   * Our (blinded) signature over the (blinded) coin.
    */
-  struct TALER_DenominationSignature sig;
+  struct TALER_BlindedDenominationSignature sig;
 
   /**
    * Hash of the denomination key (which coin was generated).
@@ -1616,7 +1616,7 @@ struct TALER_EXCHANGEDB_RefreshRevealedCoin
   /**
    * Signature generated by the exchange over the coin (in blinded format).
    */
-  struct TALER_DenominationSignature coin_sig;
+  struct TALER_BlindedDenominationSignature coin_sig;
 };
 
 
diff --git a/src/include/taler_json_lib.h b/src/include/taler_json_lib.h
index e381a7a10..26df1f113 100644
--- a/src/include/taler_json_lib.h
+++ b/src/include/taler_json_lib.h
@@ -158,6 +158,21 @@ TALER_JSON_pack_denom_sig (
   const struct TALER_DenominationSignature *sig);
 
 
+/**
+ * Generate packer instruction for a JSON field of type
+ * blinded denomination signature (that needs to be
+ * unblinded before it becomes valid).
+ *
+ * @param name name of the field to add to the object
+ * @param sig signature
+ * @return json pack specification
+ */
+struct GNUNET_JSON_PackSpec
+TALER_JSON_pack_blinded_denom_sig (
+  const char *name,
+  const struct TALER_BlindedDenominationSignature *sig);
+
+
 /**
  * Generate packer instruction for a JSON field of type
  * amount.
@@ -327,6 +342,20 @@ TALER_JSON_spec_denom_sig (const char *field,
                            struct TALER_DenominationSignature *sig);
 
 
+/**
+ * Generate line in parser specification for a
+ * blinded denomination signature.
+ *
+ * @param field name of the field
+ * @param sig the blinded signature to initialize
+ * @return corresponding field spec
+ */
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_blinded_denom_sig (
+  const char *field,
+  struct TALER_BlindedDenominationSignature *sig);
+
+
 /**
  * The expected field stores a possibly internationalized string.
  * Internationalization means that there is another field "$name_i18n"
diff --git a/src/include/taler_pq_lib.h b/src/include/taler_pq_lib.h
index 07057722a..6e69cdf6d 100644
--- a/src/include/taler_pq_lib.h
+++ b/src/include/taler_pq_lib.h
@@ -77,6 +77,18 @@ TALER_PQ_query_param_denom_sig (
   const struct TALER_DenominationSignature *denom_sig);
 
 
+/**
+ * Generate query parameter for a blinded denomination signature.  Internally,
+ * the various attributes of the signature will be serialized into on
+ * variable-size BLOB.
+ *
+ * @param x pointer to the query parameter to pass
+ */
+struct GNUNET_PQ_QueryParam
+TALER_PQ_query_param_blinded_denom_sig (
+  const struct TALER_BlindedDenominationSignature *denom_sig);
+
+
 /**
  * Generate query parameter for a JSON object (stored as a string
  * in the DB).  Note that @a x must really be a JSON object or array,
@@ -168,6 +180,19 @@ TALER_PQ_result_spec_denom_sig (const char *name,
                                 struct TALER_DenominationSignature *denom_sig);
 
 
+/**
+ * Blinded denomination signature expected.
+ *
+ * @param name name of the field in the table
+ * @param[out] denom_sig where to store the denomination signature
+ * @return array entry for the result specification to use
+ */
+struct GNUNET_PQ_ResultSpec
+TALER_PQ_result_spec_blinded_denom_sig (
+  const char *name,
+  struct TALER_BlindedDenominationSignature *denom_sig);
+
+
 /**
  * json_t expected.
  *
-- 
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