properly handle signing errors if httpd lacks signing keys by returning internal errors (and handling new return value from TEH_KS_sign)

src/exchange/taler-exchange-httpd_deposit.c

@@ -78,9 +78,15 @@ reply_deposit_success (struct MHD_Connection *connection,
                      amount_without_fee);
   dc.coin_pub = *coin_pub;
   dc.merchant = *merchant;
+  if (GNUNET_OK !=
       TEH_KS_sign (&dc.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
   return TEH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:s, s:o, s:o}",

src/exchange/taler-exchange-httpd_keystate.c

@@ -1845,8 +1845,9 @@ read_again:
  * @param purpose the message to sign
  * @param[out] pub set to the current public signing key of the exchange
  * @param[out] sig signature over purpose using current signing key
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if we lack key material
  */
-void
+int
 TEH_KS_sign (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
              struct TALER_ExchangePublicKeyP *pub,
              struct TALER_ExchangeSignatureP *sig)
@@ -1855,15 +1856,21 @@ TEH_KS_sign (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
   struct TEH_KS_StateHandle *key_state;
 
   key_state = TEH_KS_acquire ();
-  GNUNET_assert (NULL != key_state); /* This *can* happen if the exchange's keys are
+  if (NULL == key_state)
-                                        not properly maintained, but in this case we
+  {
-                                        simply have no good way forward. */
+    /* This *can* happen if the exchange's keys are
+       not properly maintained. */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+		_("Cannot sign request, no valid keys available\n"));
+    return GNUNET_SYSERR;
+  }
   *pub = key_state->current_sign_key_issue.issue.signkey_pub;
   GNUNET_assert (GNUNET_OK ==
                  GNUNET_CRYPTO_eddsa_sign (&key_state->current_sign_key_issue.signkey_priv.eddsa_priv,
                                            purpose,
                                            &sig->eddsa_signature));
   TEH_KS_release (key_state);
+  return GNUNET_OK;
 }
 
 

src/exchange/taler-exchange-httpd_keystate.h

@@ -140,8 +140,9 @@ TEH_KS_loop (void);
  * @param purpose the message to sign
  * @param[out] pub set to the current public signing key of the exchange
  * @param[out] sig signature over purpose using current signing key
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if we lack key material
  */
-void
+int
 TEH_KS_sign (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
              struct TALER_ExchangePublicKeyP *pub,
              struct TALER_ExchangeSignatureP *sig);

src/exchange/taler-exchange-httpd_payback.c

@@ -82,9 +82,15 @@ reply_payback_success (struct MHD_Connection *connection,
                      amount);
   pc.coin_pub = *coin_pub;
   pc.reserve_pub = *reserve_pub;
+  if (GNUNET_OK !=
       TEH_KS_sign (&pc.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
   return TEH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:o, s:o, s:o, s:o, s:o}",

src/exchange/taler-exchange-httpd_refresh_melt.c

@@ -135,9 +135,15 @@ reply_refresh_melt_success (struct MHD_Connection *connection,
   body.session_hash = *session_hash;
   body.noreveal_index = htons (noreveal_index);
   body.reserved = htons (0);
+  if (GNUNET_OK !=
       TEH_KS_sign (&body.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
   sig_json = GNUNET_JSON_from_data_auto (&sig);
   GNUNET_assert (NULL != sig_json);
   return TEH_RESPONSE_reply_json_pack (connection,

src/exchange/taler-exchange-httpd_refund.c

@@ -61,9 +61,15 @@ reply_refund_success (struct MHD_Connection *connection,
                      &refund->refund_amount);
   TALER_amount_hton (&rc.refund_fee,
                      &refund->refund_fee);
+  if (GNUNET_OK !=
       TEH_KS_sign (&rc.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
   return TEH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:s, s:o, s:o}",

src/exchange/taler-exchange-httpd_responses.c

@@ -474,7 +474,7 @@ TEH_RESPONSE_reply_invalid_json (struct MHD_Connection *connection)
  * Compile the transaction history of a coin into a JSON object.
  *
  * @param tl transaction history to JSON-ify
- * @return json representation of the @a rh
+ * @return json representation of the @a rh, NULL on error
  */
 json_t *
 TEH_RESPONSE_compile_transaction_history (const struct TALER_EXCHANGEDB_TransactionList *tl)
@@ -632,9 +632,15 @@ TEH_RESPONSE_compile_transaction_history (const struct TALER_EXCHANGEDB_Transact
                            &payback->value);
         pc.coin_pub = payback->coin.coin_pub;
         pc.reserve_pub = payback->reserve_pub;
+        if (GNUNET_OK !=
 	    TEH_KS_sign (&pc.purpose,
 			 &epub,
-                     &esig);
+			 &esig))
+	{
+	  GNUNET_break (0);
+	  json_decref (history);
+	  return NULL;
+	}
         GNUNET_assert (0 ==
                        json_array_append_new (history,
                                               json_pack ("{s:s, s:o, s:o, s:o, s:o, s:o}",
@@ -796,9 +802,15 @@ TEH_RESPONSE_compile_reserve_history (const struct TALER_EXCHANGEDB_ReserveHisto
 			   &payback->value);
 	pc.coin_pub = payback->coin.coin_pub;
 	pc.reserve_pub = payback->reserve_pub;
+	if (GNUNET_OK !=
 	    TEH_KS_sign (&pc.purpose,
 			 &pub,
-		     &sig);
+			 &sig))
+	{
+	  GNUNET_break (0);
+	  json_decref (json_history);
+	  return NULL;
+	}
 
 	GNUNET_assert (0 ==
 		       json_array_append_new (json_history,
@@ -852,9 +864,15 @@ TEH_RESPONSE_compile_reserve_history (const struct TALER_EXCHANGEDB_ReserveHisto
           return NULL;
         }
 	rcc.wtid = pos->details.closing->wtid;
+	if (GNUNET_OK !=
 	    TEH_KS_sign (&rcc.purpose,
 			 &pub,
-		     &sig);
+			 &sig))
+	{
+          GNUNET_break (0);
+          json_decref (json_history);
+          return NULL;
+	}
 	GNUNET_assert (0 ==
 		       json_array_append_new (json_history,
 					      json_pack ("{s:s, s:O, s:o, s:o, s:o, s:o, s:o, s:o}",

src/exchange/taler-exchange-httpd_track_transaction.c

@@ -85,9 +85,15 @@ reply_track_transaction (struct MHD_Connection *connection,
   cw.execution_time = GNUNET_TIME_absolute_hton (exec_time);
   TALER_amount_hton (&cw.coin_contribution,
                      coin_contribution);
+  if (GNUNET_OK !=
       TEH_KS_sign (&cw.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
   return TEH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:o, s:o, s:o, s:o, s:o}",

src/exchange/taler-exchange-httpd_track_transfer.c

@@ -131,9 +131,17 @@ reply_track_transfer_details (struct MHD_Connection *connection,
   wdp.h_wire = *h_wire;
   GNUNET_CRYPTO_hash_context_finish (hash_context,
                                      &wdp.h_details);
+  if (GNUNET_OK !=
       TEH_KS_sign (&wdp.purpose,
 		   &pub,
-               &sig);
+		   &sig))
+  {
+    json_decref (deposits);
+    return TEH_RESPONSE_reply_internal_error (connection,
+                                              TALER_EC_EXCHANGE_BAD_CONFIGURATION,
+                                              "no keys");
+  }
+    
   return TEH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:o, s:o, s:o, s:o, s:o, s:o, s:o, s:o}",