fix #5434 (no more salt in exchange wire replies)

src/auditor/taler-auditor.c

@@ -2095,7 +2095,7 @@ wire_transfer_information_cb (void *cls,
   struct GNUNET_HashCode hw;
 
   if (GNUNET_OK !=
-      TALER_JSON_wire_signature_hash (account_details,
+      TALER_JSON_merchant_wire_signature_hash (account_details,
                                                &hw))
   {
     wcc->qs = GNUNET_DB_STATUS_HARD_ERROR;
@@ -2411,7 +2411,7 @@ check_wire_out_cb (void *cls,
                  TALER_amount_get_zero (amount->currency,
                                         &wcc.total_deposits));
   if (GNUNET_OK !=
-      TALER_JSON_wire_signature_hash (wire,
+      TALER_JSON_merchant_wire_signature_hash (wire,
                                                &wcc.h_wire))
   {
     GNUNET_break (0);
@@ -3430,7 +3430,7 @@ deposit_cb (void *cls,
   dr.purpose.size = htonl (sizeof (dr));
   dr.h_contract_terms = *h_contract_terms;
   if (GNUNET_OK !=
-      TALER_JSON_wire_signature_hash (receiver_wire_account,
+      TALER_JSON_merchant_wire_signature_hash (receiver_wire_account,
                                                &dr.h_wire))
   {
     GNUNET_break (0);

src/exchange-lib/exchange_api_deposit.c

@@ -416,7 +416,7 @@ TALER_EXCHANGE_deposit (struct TALER_EXCHANGE_Handle *exchange,
 		 MAH_handle_is_ready (exchange));
   /* initialize h_wire */
   if (GNUNET_OK !=
-      TALER_JSON_wire_signature_hash (wire_details,
+      TALER_JSON_merchant_wire_signature_hash (wire_details,
                                                &h_wire))
   {
     GNUNET_break (0);

src/exchange-lib/exchange_api_wire.c

@@ -272,7 +272,6 @@ handle_wire_finished (void *cls,
           json_t *account;
           struct GNUNET_JSON_Specification spec_account[] = {
             GNUNET_JSON_spec_string ("url", &wa->url),
-            GNUNET_JSON_spec_string ("salt", &wa->salt),
             GNUNET_JSON_spec_fixed_auto ("master_sig", &wa->master_sig),
             GNUNET_JSON_spec_end()
           };
@@ -281,7 +280,7 @@ handle_wire_finished (void *cls,
           account = json_array_get (accounts,
                                     i);
           if (GNUNET_OK !=
-              TALER_JSON_wire_signature_check (account,
+              TALER_JSON_exchange_wire_signature_check (account,
                                                         &key_state->master_pub))
           {
             /* bogus reply */

src/exchange-lib/test_exchange_api_home/.config/taler/account-2.json

@@ -1,5 +1,4 @@
 {
   "url": "payto://x-taler-bank/localhost:8082/2",
-  "salt": "TMXB995ZZVKA02AG4074X3C6XX0BFTHY8XK76EF4BSG5XVDF069FEBN4TCKW9GS7NKZH409GKAVHMQPA3T361MC6VM7J268V3GBH42R",
+  "master_sig": "HC47BZN3C0KJ2VPMJ5EJWD2FXJ72AET0NWFE6JGSGK5CXS4GSKJJ6Z7BTS56JWM7B40SD61Z5GYYMRRE3X9JTJBVMWE0X7XHNXQ9P38"
-  "master_sig": "CK7BGHKYVAT7DMVCN00DQ0761NCTJVESZT69049BCF3SKNJKVHXXEQ5X6FH2HFGHCJ18YA1MGHBD8RRG4W3G4KJWQJDY2CGPGTHDJ2G"
 }

src/exchange-lib/test_exchange_api_home/.config/taler/x-taler-bank.json

@@ -1,5 +1,4 @@
 {
   "url": "payto://x-taler-bank/http://localhost:8082/2",
-  "salt": "WGRD0W7YKD8ZAN960B0JBRARRY0K5FQ4920Q3DJBTYH4GY7W0XNAX1F04R5B1E0RWH1NFG08TM8K1517WNCXTJM9KMH4913Q5XPK0N8",
+  "master_sig": "KQ0BWSCNVR7HGGSAMCYK8ZM30RBS1MHMXT3QBN01PZWC9TV72FEE5RJ7T84C8134EPV6WEBXXY2MTFNE8ZXST6JEJQKR8HX6FQPVY10"
-  "master_sig": "J4N0KP64MGNEQX9HST9TDWK67152MSHHM9CTZH8GSMKD607BXSAF209AQYDKYT6QJP0NQXYXC1JMM9Z405DJHGV75JFMWP4G6WB6A00"
 }

src/exchange-lib/testing_api_cmd_deposit.c

@@ -330,7 +330,7 @@ deposit_run (void *cls,
     dr.h_contract_terms = h_contract_terms;
     GNUNET_assert
       (GNUNET_OK ==
-       TALER_JSON_wire_signature_hash (ds->wire_details,
+       TALER_JSON_merchant_wire_signature_hash (ds->wire_details,
                                                 &dr.h_wire));
     dr.timestamp = GNUNET_TIME_absolute_hton (timestamp);
     dr.refund_deadline = GNUNET_TIME_absolute_hton

src/exchange-lib/testing_api_cmd_track.c

@@ -328,7 +328,7 @@ track_transaction_run (void *cls,
   /* Should not fail here, json has been parsed already */
   GNUNET_assert
     ( (GNUNET_OK ==
-       TALER_JSON_wire_signature_hash (wire_details,
+       TALER_JSON_merchant_wire_signature_hash (wire_details,
                                                 &h_wire_details)) &&
       (GNUNET_OK ==
        TALER_JSON_hash (j_contract_terms,
@@ -614,8 +614,10 @@ track_transfer_cb
         return;
       }
 
-      if (GNUNET_OK != TALER_TESTING_get_trait_wire_details
+      if (GNUNET_OK !=
-        (wire_details_cmd, 0, &wire_details))
+          TALER_TESTING_get_trait_wire_details (wire_details_cmd,
+                                                0,
+                                                &wire_details))
       {
         GNUNET_break (0);
         TALER_TESTING_interpreter_fail (is);
@@ -623,8 +625,8 @@ track_transfer_cb
       }
 
       GNUNET_assert
-        (GNUNET_OK == TALER_JSON_wire_signature_hash
+        (GNUNET_OK ==
-          (wire_details,
+         TALER_JSON_merchant_wire_signature_hash (wire_details,
                                                   &h_wire_details));
 
       if (0 != memcmp (&h_wire_details,

src/exchange-tools/taler-exchange-wire.c

@@ -59,6 +59,7 @@ sign_account_data (void *cls,
   json_t *wire;
   char *json_out;
   FILE *out;
+  int ret;
 
   if (GNUNET_NO == ai->credit_enabled)
     return;
@@ -70,8 +71,9 @@ sign_account_data (void *cls,
     global_ret = 1;
     return;
   }
-  wire = TALER_JSON_wire_signature_make (ai->payto_url,
+  wire = TALER_JSON_exchange_wire_signature_make (ai->payto_url,
                                                   &master_priv);
+  GNUNET_assert (NULL != wire);
   json_out = json_dumps (wire,
                          JSON_INDENT(2));
   json_decref (wire);
@@ -98,10 +100,20 @@ sign_account_data (void *cls,
     free (json_out);
     return;
   }
-  fprintf (out,
+  ret = fprintf (out,
                  "%s",
                  json_out);
   fclose (out);
+  if ( (0 == fclose (out)) &&
+       (-1 != ret) )
+    fprintf (stdout,
+             "Created wire account file `%s'\n",
+             ai->wire_response_filename);
+  else
+    fprintf (stderr,
+             "Failure creating wire account file `%s': %s\n",
+             ai->wire_response_filename,
+             STRERROR (errno));
   free (json_out);
 }
 

src/exchange/taler-exchange-aggregator.c

@@ -705,7 +705,7 @@ deposit_cb (void *cls,
     GNUNET_break (0);
     return GNUNET_DB_STATUS_HARD_ERROR;
   }
-  TALER_JSON_wire_signature_hash (wire,
+  TALER_JSON_merchant_wire_signature_hash (wire,
                                            &au->h_wire);
   GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
                               &au->wtid,

src/exchange/taler-exchange-httpd_deposit.c

@@ -457,7 +457,7 @@ TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
                                            "timestamp");
   }
   if (GNUNET_OK !=
-      TALER_JSON_wire_signature_hash (wire,
+      TALER_JSON_merchant_wire_signature_hash (wire,
                                                &my_h_wire))
   {
     TALER_LOG_WARNING ("Failed to parse JSON wire format specification for /deposit request\n");

src/exchange/taler-exchange-httpd_keystate.c

@@ -1633,6 +1633,9 @@ TEH_KS_release_ (const char *location,
                  struct TEH_KS_StateHandle *key_state)
 {
   GNUNET_assert (0 == pthread_mutex_lock (&internal_key_state_mutex));
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "KS released at %s\n",
+              location);
   ks_release (key_state);
   GNUNET_assert (0 == pthread_mutex_unlock (&internal_key_state_mutex));
 }
@@ -1653,6 +1656,9 @@ TEH_KS_acquire_ (const char *location)
   struct TEH_KS_StateHandle *key_state;
 
   GNUNET_assert (0 == pthread_mutex_lock (&internal_key_state_mutex));
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "KS acquired at %s\n",
+              location);
   if ( (NULL != internal_key_state) &&
        (internal_key_state->next_reload.abs_value_us <= now.abs_value_us) )
   {

src/exchange/taler-exchange-httpd_validation.c

@@ -158,7 +158,7 @@ load_account (void *cls,
     }
     GNUNET_free (url);
     if (GNUNET_OK !=
-        TALER_JSON_wire_signature_check (wire_s,
+        TALER_JSON_exchange_wire_signature_check (wire_s,
                                                   &TEH_master_public_key))
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,

src/exchange/test_taler_exchange_aggregator.c

@@ -447,7 +447,7 @@ do_deposit (struct Command *cmd)
     GNUNET_free (str);
   }
   GNUNET_assert (GNUNET_OK ==
-                 TALER_JSON_wire_signature_hash (deposit.receiver_wire_account,
+                 TALER_JSON_merchant_wire_signature_hash (deposit.receiver_wire_account,
                                                           &deposit.h_wire));
   deposit.timestamp = GNUNET_TIME_absolute_get ();
   GNUNET_TIME_round_abs (&deposit.timestamp);

src/exchangedb/test_exchangedb.c

@@ -904,7 +904,7 @@ deposit_cb (void *cls,
   deposit_rowid = rowid;
   if (NULL != wire)
     GNUNET_assert (GNUNET_OK ==
-                   TALER_JSON_wire_signature_hash (wire,
+                   TALER_JSON_merchant_wire_signature_hash (wire,
                                                             &h_wire));
   if ( (0 != memcmp (merchant_pub,
                      &deposit->merchant_pub,
@@ -1438,7 +1438,7 @@ wire_missing_cb (void *cls,
 
   if (NULL != wire)
     GNUNET_assert (GNUNET_OK ==
-                   TALER_JSON_wire_signature_hash (wire,
+                   TALER_JSON_merchant_wire_signature_hash (wire,
                                                             &h_wire));
   else
     memset (&h_wire,
@@ -1922,7 +1922,7 @@ run (void *cls)
   RND_BLK (&deposit.merchant_pub);
   RND_BLK (&deposit.h_contract_terms);
   GNUNET_assert (GNUNET_OK ==
-                 TALER_JSON_wire_signature_hash (wire,
+                 TALER_JSON_merchant_wire_signature_hash (wire,
                                                           &deposit.h_wire));
   deposit.receiver_wire_account = wire;
   deposit.amount_with_fee = value;

src/include/taler_crypto_lib.h

@@ -738,26 +738,23 @@ TALER_refresh_get_commitment (struct TALER_RefreshCommitmentP *rc,
  * hash is what is put into the contract.
  *
  * @param payto_url bank account
- * @param salt salt used to eliminate brute-force inversion
  * @param hc[out] set to the hash
  */
 void
-TALER_wire_signature_hash (const char *payto_url,
+TALER_exchange_wire_signature_hash (const char *payto_url,
-                           const char *salt,
                                     struct GNUNET_HashCode *hc);
 
+
 /**
  * Check the signature in @a wire_s.
  *
  * @param payto_url URL that is signed
- * @param salt the salt used to salt the @a payto_url when hashing
  * @param master_pub master public key of the exchange
  * @param master_sig signature of the exchange
  * @return #GNUNET_OK if signature is valid
  */
 int
-TALER_wire_signature_check (const char *payto_url,
+TALER_exchange_wire_signature_check (const char *payto_url,
-                            const char *salt,
                                      const struct TALER_MasterPublicKeyP *master_pub,
                                      const struct TALER_MasterSignatureP *master_sig);
 
@@ -766,15 +763,58 @@ TALER_wire_signature_check (const char *payto_url,
  * Create a signed wire statement for the given account.
  *
  * @param payto_url account specification
- * @param salt the salt used to salt the @a payto_url when hashing
  * @param master_priv private key to sign with
  * @param master_sig[out] where to write the signature
  */
 void
-TALER_wire_signature_make (const char *payto_url,
+TALER_exchange_wire_signature_make (const char *payto_url,
-                           const char *salt,
                                     const struct TALER_MasterPrivateKeyP *master_priv,
                                     struct TALER_MasterSignatureP *master_sig);
 
 
+/**
+ * Compute the hash of the given wire details.   The resulting
+ * hash is what is put into the contract.
+ *
+ * @param payto_url bank account
+ * @param salt salt used to eliminate brute-force inversion
+ * @param hc[out] set to the hash
+ */
+void
+TALER_merchant_wire_signature_hash (const char *payto_url,
+                                    const char *salt,
+                                    struct GNUNET_HashCode *hc);
+
+
+/**
+ * Check the signature in @a wire_s.
+ *
+ * @param payto_url URL that is signed
+ * @param salt the salt used to salt the @a payto_url when hashing
+ * @param merch_pub public key of the merchant
+ * @param merch_sig signature of the merchant
+ * @return #GNUNET_OK if signature is valid
+ */
+int
+TALER_merchant_wire_signature_check (const char *payto_url,
+                                     const char *salt,
+                                     const struct TALER_MerchantPublicKeyP *merch_pub,
+                                     const struct TALER_MerchantSignatureP *merch_sig);
+
+
+/**
+ * Create a signed wire statement for the given account.
+ *
+ * @param payto_url account specification
+ * @param salt the salt used to salt the @a payto_url when hashing
+ * @param merch_priv private key to sign with
+ * @param merch_sig[out] where to write the signature
+ */
+void
+TALER_merchant_wire_signature_make (const char *payto_url,
+                                    const char *salt,
+                                    const struct TALER_MerchantPrivateKeyP *merch_priv,
+                                    struct TALER_MerchantSignatureP *merch_sig);
+
+
 #endif

src/include/taler_exchange_service.h

@@ -479,11 +479,6 @@ struct TALER_EXCHANGE_WireAccount
    */
   const char *url;
 
-  /**
-   * Salt used to generate @e master_sig.
-   */
-  const char *salt;
-
   /**
    * Signature of the exchange over the account (was checked by the API).
    */

src/include/taler_json_lib.h

@@ -137,9 +137,23 @@ TALER_JSON_get_error_code (const json_t *json);
  * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed
  */
 int
-TALER_JSON_wire_signature_hash (const json_t *wire_s,
+TALER_JSON_merchant_wire_signature_hash (const json_t *wire_s,
                                          struct GNUNET_HashCode *hc);
 
+
+/**
+ * Compute the hash of the given wire details.   The resulting
+ * hash is what is signed by the master public key.
+ *
+ * @param wire_s wire details to hash
+ * @param hc[out] set to the hash
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed
+ */
+int
+TALER_JSON_exchange_wire_signature_hash (const json_t *wire_s,
+                                         struct GNUNET_HashCode *hc);
+
+
 /**
  * Check the signature in @a wire_s.
  *
@@ -148,7 +162,7 @@ TALER_JSON_wire_signature_hash (const json_t *wire_s,
  * @return #GNUNET_OK if signature is valid
  */
 int
-TALER_JSON_wire_signature_check (const json_t *wire_s,
+TALER_JSON_exchange_wire_signature_check (const json_t *wire_s,
                                           const struct TALER_MasterPublicKeyP *master_pub);
 
 
@@ -159,7 +173,7 @@ TALER_JSON_wire_signature_check (const json_t *wire_s,
  * @param master_priv private key to sign with, NULL to not sign
  */
 json_t *
-TALER_JSON_wire_signature_make (const char *payto_url,
+TALER_JSON_exchange_wire_signature_make (const char *payto_url,
                                          const struct TALER_MasterPrivateKeyP *master_priv);
 
 

src/include/taler_signatures.h

@@ -178,6 +178,12 @@
  */
 #define TALER_SIGNATURE_MERCHANT_PAY_SESSION 1106
 
+/**
+ * Signature where the merchant confirms its own (salted)
+ * wire details (not yet really used).
+ */
+#define TALER_SIGNATURE_MERCHANT_WIRE_DETAILS 1107
+
 
 /*********************/
 /* Wallet signatures */

src/include/taler_wire_lib.h

@@ -46,6 +46,7 @@ struct TALER_WIRE_Plugin *
 TALER_WIRE_plugin_load (const struct GNUNET_CONFIGURATION_Handle *cfg,
                         const char *plugin_name);
 
+
 /**
  * Unload a WIRE plugin.
  *

src/json/json_wire.c

@@ -34,7 +34,39 @@
  * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed
  */
 int
-TALER_JSON_wire_signature_hash (const json_t *wire_s,
+TALER_JSON_exchange_wire_signature_hash (const json_t *wire_s,
+                                         struct GNUNET_HashCode *hc)
+{
+  const char *payto_url;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_string ("url", &payto_url),
+    GNUNET_JSON_spec_end ()
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (wire_s,
+                         spec,
+                         NULL, NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  TALER_exchange_wire_signature_hash (payto_url,
+                                      hc);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Compute the hash of the given wire details.   The resulting
+ * hash is what is put into the contract.
+ *
+ * @param wire_s wire details to hash
+ * @param hc[out] set to the hash
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed
+ */
+int
+TALER_JSON_merchant_wire_signature_hash (const json_t *wire_s,
                                          struct GNUNET_HashCode *hc)
 {
   const char *payto_url;
@@ -53,7 +85,7 @@ TALER_JSON_wire_signature_hash (const json_t *wire_s,
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
-  TALER_wire_signature_hash (payto_url,
+  TALER_merchant_wire_signature_hash (payto_url,
                                       salt,
                                       hc);
   return GNUNET_OK;
@@ -68,15 +100,13 @@ TALER_JSON_wire_signature_hash (const json_t *wire_s,
  * @return #GNUNET_OK if signature is valid
  */
 int
-TALER_JSON_wire_signature_check (const json_t *wire_s,
+TALER_JSON_exchange_wire_signature_check (const json_t *wire_s,
                                           const struct TALER_MasterPublicKeyP *master_pub)
 {
   const char *payto_url;
-  const char *salt;
   struct TALER_MasterSignatureP master_sig;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_string ("url", &payto_url),
-    GNUNET_JSON_spec_string ("salt", &salt),
     GNUNET_JSON_spec_fixed_auto ("master_sig", &master_sig),
     GNUNET_JSON_spec_end ()
   };
@@ -89,8 +119,7 @@ TALER_JSON_wire_signature_check (const json_t *wire_s,
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
-  return TALER_wire_signature_check (payto_url,
+  return TALER_exchange_wire_signature_check (payto_url,
-                                     salt,
                                               master_pub,
                                               &master_sig);
 }
@@ -103,39 +132,18 @@ TALER_JSON_wire_signature_check (const json_t *wire_s,
  * @param master_priv private key to sign with, NULL to not sign
  */
 json_t *
-TALER_JSON_wire_signature_make (const char *payto_url,
+TALER_JSON_exchange_wire_signature_make (const char *payto_url,
                                          const struct TALER_MasterPrivateKeyP *master_priv)
 {
   struct TALER_MasterSignatureP master_sig;
-  struct GNUNET_HashCode salt;
-  char *salt_str;
-  json_t *ret;
 
-  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
+  TALER_exchange_wire_signature_make (payto_url,
-                              &salt,
-                              sizeof (salt));
-  salt_str = GNUNET_STRINGS_data_to_string_alloc (&salt,
-                                                  sizeof (salt));
-  if (NULL != master_priv)
-  {
-    TALER_wire_signature_make (payto_url,
-                               salt_str,
                                       master_priv,
                                       &master_sig);
-    ret = json_pack ("{s:s, s:s, s:o}",
+  return json_pack ("{s:s, s:o}",
                     "url", payto_url,
-                     "salt", salt_str,
                     "master_sig", GNUNET_JSON_from_data_auto (&master_sig));
 }
-  else
-  {
-    ret = json_pack ("{s:s, s:s}",
-                     "url", payto_url,
-                     "salt", salt_str);
-  }
-  GNUNET_free (salt_str);
-  return ret;
-}
 
 
 /**

src/util/crypto_wire.c

@@ -22,28 +22,25 @@
 #include "taler_crypto_lib.h"
 #include "taler_signatures.h"
 
+
 /**
  * Compute the hash of the given wire details.   The resulting
  * hash is what is put into the contract.
  *
  * @param payto_url bank account
- * @param salt salt used to eliminate brute-force inversion
  * @param hc[out] set to the hash
  */
 void
-TALER_wire_signature_hash (const char *payto_url,
+TALER_exchange_wire_signature_hash (const char *payto_url,
-                           const char *salt,
                                     struct GNUNET_HashCode *hc)
 {
   GNUNET_assert (GNUNET_YES ==
                  GNUNET_CRYPTO_kdf (hc,
                                     sizeof (*hc),
-                                    salt,
-                                    strlen (salt) + 1,
                                     payto_url,
                                     strlen (payto_url) + 1,
-                                    "wire-signature",
+                                    "exchange-wire-signature",
-                                    strlen ("wire-signature"),
+                                    strlen ("exchange-wire-signature"),
                                     NULL, 0));
 }
 
@@ -52,14 +49,12 @@ TALER_wire_signature_hash (const char *payto_url,
  * Check the signature in @a wire_s.
  *
  * @param payto_url URL that is signed
- * @param salt the salt used to salt the @a payto_url when hashing
  * @param master_pub master public key of the exchange
  * @param master_sig signature of the exchange
  * @return #GNUNET_OK if signature is valid
  */
 int
-TALER_wire_signature_check (const char *payto_url,
+TALER_exchange_wire_signature_check (const char *payto_url,
-                            const char *salt,
                                      const struct TALER_MasterPublicKeyP *master_pub,
                                      const struct TALER_MasterSignatureP *master_sig)
 {
@@ -67,8 +62,7 @@ TALER_wire_signature_check (const char *payto_url,
 
   wd.purpose.purpose = htonl (TALER_SIGNATURE_MASTER_WIRE_DETAILS);
   wd.purpose.size = htonl (sizeof (wd));
-  TALER_wire_signature_hash (payto_url,
+  TALER_exchange_wire_signature_hash (payto_url,
-                             salt,
                                       &wd.h_wire_details);
   return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_WIRE_DETAILS,
                                      &wd.purpose,
@@ -81,13 +75,11 @@ TALER_wire_signature_check (const char *payto_url,
  * Create a signed wire statement for the given account.
  *
  * @param payto_url account specification
- * @param salt the salt used to salt the @a payto_url when hashing
  * @param master_priv private key to sign with
  * @param master_sig[out] where to write the signature
  */
 void
-TALER_wire_signature_make (const char *payto_url,
+TALER_exchange_wire_signature_make (const char *payto_url,
-                           const char *salt,
                                     const struct TALER_MasterPrivateKeyP *master_priv,
                                     struct TALER_MasterSignatureP *master_sig)
 {
@@ -95,8 +87,7 @@ TALER_wire_signature_make (const char *payto_url,
 
   wd.purpose.purpose = htonl (TALER_SIGNATURE_MASTER_WIRE_DETAILS);
   wd.purpose.size = htonl (sizeof (wd));
-  TALER_wire_signature_hash (payto_url,
+  TALER_exchange_wire_signature_hash (payto_url,
-                             salt,
                                       &wd.h_wire_details);
   GNUNET_assert (GNUNET_OK ==
                  GNUNET_CRYPTO_eddsa_sign (&master_priv->eddsa_priv,
@@ -105,4 +96,87 @@ TALER_wire_signature_make (const char *payto_url,
 }
 
 
+/**
+ * Compute the hash of the given wire details.   The resulting
+ * hash is what is put into the contract.
+ *
+ * @param payto_url bank account
+ * @param salt salt used to eliminate brute-force inversion
+ * @param hc[out] set to the hash
+ */
+void
+TALER_merchant_wire_signature_hash (const char *payto_url,
+                                    const char *salt,
+                                    struct GNUNET_HashCode *hc)
+{
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_CRYPTO_kdf (hc,
+                                    sizeof (*hc),
+                                    salt,
+                                    strlen (salt) + 1,
+                                    payto_url,
+                                    strlen (payto_url) + 1,
+                                    "merchant-wire-signature",
+                                    strlen ("merchant-wire-signature"),
+                                    NULL, 0));
+}
+
+
+/**
+ * Check the signature in @a merch_sig. (Not yet used anywhere.)
+ *
+ * @param payto_url URL that is signed
+ * @param salt the salt used to salt the @a payto_url when hashing
+ * @param merch_pub master public key of the merchant
+ * @param merch_sig signature of the merchant
+ * @return #GNUNET_OK if signature is valid
+ */
+int
+TALER_merchant_wire_signature_check (const char *payto_url,
+                                     const char *salt,
+                                     const struct TALER_MerchantPublicKeyP *merch_pub,
+                                     const struct TALER_MerchantSignatureP *merch_sig)
+{
+  struct TALER_MasterWireDetailsPS wd;
+
+  wd.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_WIRE_DETAILS);
+  wd.purpose.size = htonl (sizeof (wd));
+  TALER_merchant_wire_signature_hash (payto_url,
+                                      salt,
+                                      &wd.h_wire_details);
+  return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MERCHANT_WIRE_DETAILS,
+                                     &wd.purpose,
+                                     &merch_sig->eddsa_sig,
+                                     &merch_pub->eddsa_pub);
+}
+
+
+/**
+ * Create a signed wire statement for the given account. (Not yet used anywhere.)
+ *
+ * @param payto_url account specification
+ * @param salt the salt used to salt the @a payto_url when hashing
+ * @param merchant_priv private key to sign with
+ * @param merchant_sig[out] where to write the signature
+ */
+void
+TALER_merchant_wire_signature_make (const char *payto_url,
+                                    const char *salt,
+                                    const struct TALER_MerchantPrivateKeyP *merch_priv,
+                                    struct TALER_MerchantSignatureP *merch_sig)
+{
+  struct TALER_MasterWireDetailsPS wd;
+
+  wd.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_WIRE_DETAILS);
+  wd.purpose.size = htonl (sizeof (wd));
+  TALER_merchant_wire_signature_hash (payto_url,
+                                      salt,
+                                      &wd.h_wire_details);
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CRYPTO_eddsa_sign (&merch_priv->eddsa_priv,
+                                           &wd.purpose,
+                                           &merch_sig->eddsa_sig));
+}
+
+
 /* end of crypto_wire.c */