add offline signature to drain profits (#4960)

contrib/gana

@@ -1 +1 @@
-Subproject commit 7bfe1654eeab7e7eacb4f6eb45ad52ffe4511c4d
+Subproject commit f4ec586e0fc4c067fbc9e14b21d66f2573717c1e

src/include/taler_crypto_lib.h

@@ -4546,6 +4546,55 @@ TALER_exchange_offline_partner_details_verify (
   const struct TALER_MasterSignatureP *master_sig);
 
 
+/**
+ * Create offline signature about wiring profits to a
+ * regular non-escrowed account of the exchange.
+ *
+ * @param wtid (random) wire transfer ID to be used
+ * @param date when was the profit drain approved (not exact time of execution)
+ * @param amount how much should be wired
+ * @param account_section configuration section of the
+ *        exchange specifying the account to be debited
+ * @param payto_uri target account to be credited
+ * @param master_priv private key to sign with
+ * @param[out] master_sig where to write the signature
+ */
+void
+TALER_exchange_offline_profit_drain_sign (
+  const struct TALER_WireTransferIdentifierRawP *wtid,
+  struct GNUNET_TIME_Timestamp date,
+  const struct TALER_Amount *amount,
+  const char *account_section,
+  const char *payto_uri,
+  const struct TALER_MasterPrivateKeyP *master_priv,
+  struct TALER_MasterSignatureP *master_sig);
+
+
+/**
+ * Verify offline signature about wiring profits to a
+ * regular non-escrowed account of the exchange.
+ *
+ * @param wtid (random) wire transfer ID to be used
+ * @param date when was the profit drain approved (not exact time of execution)
+ * @param amount how much should be wired
+ * @param account_section configuration section of the
+ *        exchange specifying the account to be debited
+ * @param payto_uri target account to be credited
+ * @param master_pub public key to verify signature against
+ * @param master_sig the signature
+ * @return #GNUNET_OK if the signature is valid
+ */
+enum GNUNET_GenericReturnValue
+TALER_exchange_offline_profit_drain_verify (
+  const struct TALER_WireTransferIdentifierRawP *wtid,
+  struct GNUNET_TIME_Timestamp date,
+  const struct TALER_Amount *amount,
+  const char *account_section,
+  const char *payto_uri,
+  const struct TALER_MasterPublicKeyP *master_pub,
+  const struct TALER_MasterSignatureP *master_sig);
+
+
 /**
  * Create security module EdDSA signature.
  *

src/include/taler_exchangedb_lib.h

@@ -95,7 +95,7 @@ struct TALER_EXCHANGEDB_AccountInfo
  * @param[out] ret where the resulting total is to be stored
  * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
  */
-int
+enum GNUNET_GenericReturnValue
 TALER_EXCHANGEDB_calculate_transaction_list_totals (
   struct TALER_EXCHANGEDB_TransactionList *tl,
   const struct TALER_Amount *off,

src/util/offline_signatures.c

@@ -1145,4 +1145,88 @@ TALER_exchange_offline_partner_details_verify (
 }
 
 
+GNUNET_NETWORK_STRUCT_BEGIN
+
+/**
+ * Message signed by account to drain profits
+ * from the escrow account of the exchange.
+ */
+struct TALER_DrainProfitPS
+{
+
+  /**
+   * Purpose is #TALER_SIGNATURE_MASTER_DRAIN_PROFITS
+   */
+  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
+  struct TALER_WireTransferIdentifierRawP wtid;
+  struct GNUNET_TIME_TimestampNBO date;
+  struct TALER_AmountNBO amount;
+  struct GNUNET_HashCode h_section;
+  struct TALER_PaytoHashP h_payto;
+};
+
+GNUNET_NETWORK_STRUCT_END
+
+
+void
+TALER_exchange_offline_profit_drain_sign (
+  const struct TALER_WireTransferIdentifierRawP *wtid,
+  struct GNUNET_TIME_Timestamp date,
+  const struct TALER_Amount *amount,
+  const char *account_section,
+  const char *payto_uri,
+  const struct TALER_MasterPrivateKeyP *master_priv,
+  struct TALER_MasterSignatureP *master_sig)
+{
+  struct TALER_DrainProfitPS wd = {
+    .purpose.purpose = htonl (TALER_SIGNATURE_MASTER_DRAIN_PROFIT),
+    .purpose.size = htonl (sizeof (wd)),
+    .wtid = *wtid,
+    .date = GNUNET_TIME_timestamp_hton (date),
+  };
+
+  GNUNET_CRYPTO_hash (account_section,
+                      strlen (account_section) + 1,
+                      &wd.h_section);
+  TALER_payto_hash (payto_uri,
+                    &wd.h_payto);
+  TALER_amount_hton (&wd.amount,
+                     amount);
+  GNUNET_CRYPTO_eddsa_sign (&master_priv->eddsa_priv,
+                            &wd,
+                            &master_sig->eddsa_signature);
+}
+
+
+enum GNUNET_GenericReturnValue
+TALER_exchange_offline_profit_drain_verify (
+  const struct TALER_WireTransferIdentifierRawP *wtid,
+  struct GNUNET_TIME_Timestamp date,
+  const struct TALER_Amount *amount,
+  const char *account_section,
+  const char *payto_uri,
+  const struct TALER_MasterPublicKeyP *master_pub,
+  const struct TALER_MasterSignatureP *master_sig)
+{
+  struct TALER_DrainProfitPS wd = {
+    .purpose.purpose = htonl (TALER_SIGNATURE_MASTER_DRAIN_PROFIT),
+    .purpose.size = htonl (sizeof (wd)),
+    .wtid = *wtid,
+    .date = GNUNET_TIME_timestamp_hton (date),
+  };
+
+  GNUNET_CRYPTO_hash (account_section,
+                      strlen (account_section) + 1,
+                      &wd.h_section);
+  TALER_payto_hash (payto_uri,
+                    &wd.h_payto);
+  TALER_amount_hton (&wd.amount,
+                     amount);
+  return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_DRAIN_PROFIT,
+                                     &wd,
+                                     &master_sig->eddsa_signature,
+                                     &master_pub->eddsa_pub);
+}
+
+
 /* end of offline_signatures.c */