diff --git a/src/exchange/taler-exchange-httpd_keys.c b/src/exchange/taler-exchange-httpd_keys.c
index e5a54447b..4b1a6213c 100644
--- a/src/exchange/taler-exchange-httpd_keys.c
+++ b/src/exchange/taler-exchange-httpd_keys.c
@@ -2411,54 +2411,40 @@ TEH_keys_denomination_by_hash2 (
 }
 
 
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TEH_keys_denomination_sign (const struct TALER_DenominationHash *h_denom_pub,
                             const struct TALER_BlindedPlanchet *bp,
-                            enum TALER_ErrorCode *ec)
+                            struct TALER_BlindedDenominationSignature *bs)
 {
   struct TEH_KeyStateHandle *ksh;
-  struct TALER_BlindedDenominationSignature none;
   struct HelperDenomination *hd;
 
-  memset (&none,
-          0,
-          sizeof (none));
   ksh = TEH_keys_get_state ();
   if (NULL == ksh)
-  {
-    *ec = TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING;
-    return none;
-  }
+    return TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING;
   hd = GNUNET_CONTAINER_multihashmap_get (ksh->helpers->denom_keys,
                                           &h_denom_pub->hash);
   if (NULL == hd)
-  {
-    *ec = TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN;
-    return none;
-  }
+    return TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN;
   if (bp->cipher != hd->denom_pub.cipher)
-  {
-    *ec = TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
-    return none;
-  }
+    return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
   switch (hd->denom_pub.cipher)
   {
   case TALER_DENOMINATION_RSA:
-    return TALER_CRYPTO_helper_rsa_sign (ksh->helpers->rsadh,
-                                         &hd->h_details.h_rsa,
-                                         bp->details.rsa_blinded_planchet.
-                                         blinded_msg,
-                                         bp->details.rsa_blinded_planchet.
-                                         blinded_msg_size,
-                                         ec);
+    return TALER_CRYPTO_helper_rsa_sign (
+      ksh->helpers->rsadh,
+      &hd->h_details.h_rsa,
+      bp->details.rsa_blinded_planchet.blinded_msg,
+      bp->details.rsa_blinded_planchet.blinded_msg_size,
+      bs);
   case TALER_DENOMINATION_CS:
-    return TALER_CRYPTO_helper_cs_sign (ksh->helpers->csdh,
-                                        &hd->h_details.h_cs,
-                                        &bp->details.cs_blinded_planchet,
-                                        ec);
+    return TALER_CRYPTO_helper_cs_sign (
+      ksh->helpers->csdh,
+      &hd->h_details.h_cs,
+      &bp->details.cs_blinded_planchet,
+      bs);
   default:
-    *ec = TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
-    return none;
+    return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
   }
 }
 
diff --git a/src/exchange/taler-exchange-httpd_keys.h b/src/exchange/taler-exchange-httpd_keys.h
index 07925f7fd..a329c4f12 100644
--- a/src/exchange/taler-exchange-httpd_keys.h
+++ b/src/exchange/taler-exchange-httpd_keys.h
@@ -173,14 +173,13 @@ TEH_keys_denomination_by_hash2 (
  *
  * @param h_denom_pub hash of the public key to use to sign
  * @param bp blinded planchet to sign
- * @param[out] ec set to the error code (or #TALER_EC_NONE on success)
- * @return signature, the value inside the structure will be NULL on failure,
- *         see @a ec for details about the failure
+ * @param[out] bs set to the blind signature on success
+ * @return #TALER_EC_NONE on success
  */
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TEH_keys_denomination_sign (const struct TALER_DenominationHash *h_denom_pub,
                             const struct TALER_BlindedPlanchet *bp,
-                            enum TALER_ErrorCode *ec);
+                            struct TALER_BlindedDenominationSignature *bs);
 
 
 /**
diff --git a/src/exchange/taler-exchange-httpd_refreshes_reveal.c b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
index ce56ebb10..0d8f7bf9b 100644
--- a/src/exchange/taler-exchange-httpd_refreshes_reveal.c
+++ b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
@@ -607,13 +607,12 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
   /* create fresh coin signatures */
   for (unsigned int i = 0; i<rctx->num_fresh_coins; i++)
   {
-    enum TALER_ErrorCode ec = TALER_EC_NONE;
+    enum TALER_ErrorCode ec;
 
-    rrcs[i].coin_sig
-      = TEH_keys_denomination_sign (
-          &rrcs[i].h_denom_pub,
-          &rcds[i].blinded_planchet,
-          &ec);
+    ec = TEH_keys_denomination_sign (
+      &rrcs[i].h_denom_pub,
+      &rcds[i].blinded_planchet,
+      &rrcs[i].coin_sig);
     if (TALER_EC_NONE != ec)
     {
       GNUNET_break (0);
diff --git a/src/exchange/taler-exchange-httpd_withdraw.c b/src/exchange/taler-exchange-httpd_withdraw.c
index 8598f1322..7572f85d2 100644
--- a/src/exchange/taler-exchange-httpd_withdraw.c
+++ b/src/exchange/taler-exchange-httpd_withdraw.c
@@ -499,12 +499,10 @@ TEH_handler_withdraw (struct TEH_RequestContext *rc,
   // TODO: if CS: check nonce for reuse
 
   /* Sign before transaction! */
-  ec = TALER_EC_NONE;
-  // FIXME: swap arguments!
-  wc.collectable.sig = TEH_keys_denomination_sign (
+  ec = TEH_keys_denomination_sign (
     &wc.collectable.denom_pub_hash,
     &wc.blinded_planchet,
-    &ec);
+    &wc.collectable.sig);
   if (TALER_EC_NONE != ec)
   {
     GNUNET_break (0);
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index dc721436b..d6014259d 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -1791,17 +1791,16 @@ TALER_CRYPTO_helper_rsa_poll (struct TALER_CRYPTO_RsaDenominationHelper *dh);
  * @param h_rsa hash of the RSA public key to use to sign
  * @param msg message to sign
  * @param msg_size number of bytes in @a msg
- * @param[out] ec set to the error code (or #TALER_EC_NONE on success)
- * @return signature, the value inside the structure will be NULL on failure,
- *         see @a ec for details about the failure
+ * @param[out] bs set to the blind signature
+ * @return #TALER_EC_NONE on success
  */
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TALER_CRYPTO_helper_rsa_sign (
   struct TALER_CRYPTO_RsaDenominationHelper *dh,
   const struct TALER_RsaPubHashP *h_rsa,
   const void *msg,
   size_t msg_size,
-  enum TALER_ErrorCode *ec);
+  struct TALER_BlindedDenominationSignature *bs);
 
 
 /**
@@ -1912,16 +1911,15 @@ TALER_CRYPTO_helper_cs_poll (struct TALER_CRYPTO_CsDenominationHelper *dh);
  * @param dh helper process connection
  * @param h_cs hash of the CS public key to use to sign
  * @param blinded_planchet blinded planchet containing c and nonce
- * @param[out] ec set to the error code (or #TALER_EC_NONE on success)
- * @return signature, the value inside the structure will be NULL on failure,
- *         see @a ec for details about the failure
+ * @param[out] bs set to the blind signature
+ * @return #TALER_EC_NONE on success
  */
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TALER_CRYPTO_helper_cs_sign (
   struct TALER_CRYPTO_CsDenominationHelper *dh,
   const struct TALER_CsPubHashP *h_cs,
   const struct TALER_BlindedCsPlanchet *blinded_planchet,
-  enum TALER_ErrorCode *ec);
+  struct TALER_BlindedDenominationSignature *bs);
 
 
 /**
diff --git a/src/util/crypto_helper_cs.c b/src/util/crypto_helper_cs.c
index 019d1902b..874679cf0 100644
--- a/src/util/crypto_helper_cs.c
+++ b/src/util/crypto_helper_cs.c
@@ -378,17 +378,16 @@ more:
 }
 
 
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TALER_CRYPTO_helper_cs_sign (
   struct TALER_CRYPTO_CsDenominationHelper *dh,
   const struct TALER_CsPubHashP *h_cs,
   const struct TALER_BlindedCsPlanchet *blinded_planchet,
-  enum TALER_ErrorCode *ec)
+  struct TALER_BlindedDenominationSignature *bs)
 {
-  struct TALER_BlindedDenominationSignature ds = {
-    .cipher = TALER_DENOMINATION_INVALID
-  };
+  enum TALER_ErrorCode ec = TALER_EC_INVALID;
 
+  bs->cipher = TALER_DENOMINATION_INVALID;
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Starting signature process\n");
   if (GNUNET_OK !=
@@ -396,8 +395,7 @@ TALER_CRYPTO_helper_cs_sign (
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Failed to connect to helper\n");
-    *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
-    return ds;
+    return TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
   }
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -420,8 +418,7 @@ TALER_CRYPTO_helper_cs_sign (
       GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
                            "send");
       do_disconnect (dh);
-      *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
-      return ds;
+      return TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
     }
   }
 
@@ -434,7 +431,6 @@ TALER_CRYPTO_helper_cs_sign (
       = (const struct GNUNET_MessageHeader *) buf;
     bool finished = false;
 
-    *ec = TALER_EC_INVALID;
     while (1)
     {
       uint16_t msize;
@@ -454,20 +450,20 @@ TALER_CRYPTO_helper_cs_sign (
         {
           GNUNET_assert (finished);
           GNUNET_assert (0 == off);
-          return ds;
+          return ec;
         }
         GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
                              "recv");
         do_disconnect (dh);
-        *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
+        ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
         break;
       }
       if (0 == ret)
       {
         GNUNET_break (0 == off);
         if (! finished)
-          *ec = TALER_EC_EXCHANGE_SIGNKEY_HELPER_BUG;
-        return ds;
+          ec = TALER_EC_EXCHANGE_SIGNKEY_HELPER_BUG;
+        return ec;
       }
       off += ret;
 more:
@@ -483,26 +479,26 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         if (finished)
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         {
           const struct TALER_CRYPTO_SignResponse *sr =
             (const struct TALER_CRYPTO_SignResponse *) buf;
-          // TODO: add nullcheck
+
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       "Received signature\n");
-          *ec = TALER_EC_NONE;
+          ec = TALER_EC_NONE;
           finished = true;
-          ds.cipher = TALER_DENOMINATION_CS;
-          ds.details.blinded_cs_answer = sr->cs_answer;
+          bs->cipher = TALER_DENOMINATION_CS;
+          bs->details.blinded_cs_answer = sr->cs_answer;
           break;
         }
       case TALER_HELPER_CS_MT_RES_SIGN_FAILURE:
@@ -510,14 +506,14 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         {
           const struct TALER_CRYPTO_SignFailure *sf =
             (const struct TALER_CRYPTO_SignFailure *) buf;
 
-          *ec = (enum TALER_ErrorCode) ntohl (sf->ec);
+          ec = (enum TALER_ErrorCode) ntohl (sf->ec);
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       "Signing failed!\n");
           finished = true;
@@ -532,7 +528,7 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         break; /* while(1) loop ensures we recvfrom() again */
@@ -545,7 +541,7 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         break; /* while(1) loop ensures we recvfrom() again */
@@ -560,7 +556,7 @@ more:
                     "Received unexpected message of type %u\n",
                     ntohs (hdr->type));
         do_disconnect (dh);
-        *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+        ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
         goto end;
       }
       memmove (buf,
@@ -571,8 +567,8 @@ more:
     } /* while(1) */
 end:
     if (finished)
-      TALER_blinded_denom_sig_free (&ds);
-    return ds;
+      TALER_blinded_denom_sig_free (bs);
+    return ec;
   }
 }
 
diff --git a/src/util/crypto_helper_rsa.c b/src/util/crypto_helper_rsa.c
index 75fe33c03..d3f498c07 100644
--- a/src/util/crypto_helper_rsa.c
+++ b/src/util/crypto_helper_rsa.c
@@ -387,18 +387,17 @@ more:
 }
 
 
-struct TALER_BlindedDenominationSignature
+enum TALER_ErrorCode
 TALER_CRYPTO_helper_rsa_sign (
   struct TALER_CRYPTO_RsaDenominationHelper *dh,
   const struct TALER_RsaPubHashP *h_rsa,
   const void *msg,
   size_t msg_size,
-  enum TALER_ErrorCode *ec)
+  struct TALER_BlindedDenominationSignature *bs)
 {
-  struct TALER_BlindedDenominationSignature ds = {
-    .cipher = TALER_DENOMINATION_INVALID
-  };
+  enum TALER_ErrorCode ec = TALER_EC_INVALID;
 
+  bs->cipher = TALER_DENOMINATION_INVALID;
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Starting signature process\n");
   if (GNUNET_OK !=
@@ -406,8 +405,7 @@ TALER_CRYPTO_helper_rsa_sign (
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Failed to connect to helper\n");
-    *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
-    return ds;
+    return TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
   }
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -432,8 +430,7 @@ TALER_CRYPTO_helper_rsa_sign (
       GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
                            "send");
       do_disconnect (dh);
-      *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
-      return ds;
+      return TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
     }
   }
 
@@ -446,7 +443,6 @@ TALER_CRYPTO_helper_rsa_sign (
       = (const struct GNUNET_MessageHeader *) buf;
     bool finished = false;
 
-    *ec = TALER_EC_INVALID;
     while (1)
     {
       uint16_t msize;
@@ -466,20 +462,20 @@ TALER_CRYPTO_helper_rsa_sign (
         {
           GNUNET_assert (finished);
           GNUNET_assert (0 == off);
-          return ds;
+          return ec;
         }
         GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
                              "recv");
         do_disconnect (dh);
-        *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
+        ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_UNAVAILABLE;
         break;
       }
       if (0 == ret)
       {
         GNUNET_break (0 == off);
         if (! finished)
-          *ec = TALER_EC_EXCHANGE_SIGNKEY_HELPER_BUG;
-        return ds;
+          ec = TALER_EC_EXCHANGE_SIGNKEY_HELPER_BUG;
+        return ec;
       }
       off += ret;
 more:
@@ -495,14 +491,14 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         if (finished)
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         {
@@ -517,15 +513,15 @@ more:
           {
             GNUNET_break_op (0);
             do_disconnect (dh);
-            *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+            ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
             goto end;
           }
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       "Received signature\n");
-          *ec = TALER_EC_NONE;
+          ec = TALER_EC_NONE;
           finished = true;
-          ds.cipher = TALER_DENOMINATION_RSA;
-          ds.details.blinded_rsa_signature = rsa_signature;
+          bs->cipher = TALER_DENOMINATION_RSA;
+          bs->details.blinded_rsa_signature = rsa_signature;
           break;
         }
       case TALER_HELPER_RSA_MT_RES_SIGN_FAILURE:
@@ -533,14 +529,14 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         {
           const struct TALER_CRYPTO_SignFailure *sf =
             (const struct TALER_CRYPTO_SignFailure *) buf;
 
-          *ec = (enum TALER_ErrorCode) ntohl (sf->ec);
+          ec = (enum TALER_ErrorCode) ntohl (sf->ec);
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       "Signing failed!\n");
           finished = true;
@@ -555,7 +551,7 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         break; /* while(1) loop ensures we recvfrom() again */
@@ -568,7 +564,7 @@ more:
         {
           GNUNET_break_op (0);
           do_disconnect (dh);
-          *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+          ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
           goto end;
         }
         break; /* while(1) loop ensures we recvfrom() again */
@@ -583,7 +579,7 @@ more:
                     "Received unexpected message of type %u\n",
                     ntohs (hdr->type));
         do_disconnect (dh);
-        *ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
+        ec = TALER_EC_EXCHANGE_DENOMINATION_HELPER_BUG;
         goto end;
       }
       memmove (buf,
@@ -594,8 +590,8 @@ more:
     } /* while(1) */
 end:
     if (finished)
-      TALER_blinded_denom_sig_free (&ds);
-    return ds;
+      TALER_blinded_denom_sig_free (bs);
+    return ec;
   }
 }
 
diff --git a/src/util/test_helper_cs.c b/src/util/test_helper_cs.c
index dd807b254..a0dbebd62 100644
--- a/src/util/test_helper_cs.c
+++ b/src/util/test_helper_cs.c
@@ -456,11 +456,11 @@ test_signing (struct TALER_CRYPTO_CsDenominationHelper *dh)
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                   "Requesting signature with key %s\n",
                   GNUNET_h2s (&keys[i].h_cs.hash));
-      ds = TALER_CRYPTO_helper_cs_sign (dh,
+      ec = TALER_CRYPTO_helper_cs_sign (dh,
                                         &keys[i].h_cs,
                                         &pd.blinded_planchet.details.
                                         cs_blinded_planchet,
-                                        &ec);
+                                        &ds);
     }
     switch (ec)
     {
@@ -552,11 +552,11 @@ test_signing (struct TALER_CRYPTO_CsDenominationHelper *dh)
                                            &c_hash,
                                            &pd));
 
-    ds = TALER_CRYPTO_helper_cs_sign (dh,
+    ec = TALER_CRYPTO_helper_cs_sign (dh,
                                       &rnd,
                                       &pd.blinded_planchet.details.
                                       cs_blinded_planchet,
-                                      &ec);
+                                      &ds);
     if (TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN != ec)
     {
       if (TALER_EC_NONE == ec)
@@ -645,11 +645,11 @@ perf_signing (struct TALER_CRYPTO_CsDenominationHelper *dh,
           struct GNUNET_TIME_Absolute start = GNUNET_TIME_absolute_get ();
           struct GNUNET_TIME_Relative delay;
 
-          ds = TALER_CRYPTO_helper_cs_sign (dh,
+          ec = TALER_CRYPTO_helper_cs_sign (dh,
                                             &keys[i].h_cs,
                                             &pd.blinded_planchet.details.
                                             cs_blinded_planchet,
-                                            &ec);
+                                            &ds);
           if (TALER_EC_NONE != ec)
             break;
           delay = GNUNET_TIME_absolute_get_duration (start);
diff --git a/src/util/test_helper_rsa.c b/src/util/test_helper_rsa.c
index 33363b1fb..679f5d7f4 100644
--- a/src/util/test_helper_rsa.c
+++ b/src/util/test_helper_rsa.c
@@ -304,13 +304,13 @@ test_signing (struct TALER_CRYPTO_RsaDenominationHelper *dh)
                    int) pd.blinded_planchet.details.rsa_blinded_planchet.
                   blinded_msg_size,
                   GNUNET_h2s (&keys[i].h_rsa.hash));
-      ds = TALER_CRYPTO_helper_rsa_sign (dh,
+      ec = TALER_CRYPTO_helper_rsa_sign (dh,
                                          &keys[i].h_rsa,
                                          pd.blinded_planchet.details.
                                          rsa_blinded_planchet.blinded_msg,
                                          pd.blinded_planchet.details.
                                          rsa_blinded_planchet.blinded_msg_size,
-                                         &ec);
+                                         &ds);
       TALER_blinded_planchet_free (&pd.blinded_planchet);
     }
     switch (ec)
@@ -405,11 +405,11 @@ test_signing (struct TALER_CRYPTO_RsaDenominationHelper *dh)
     GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
                                 &rnd,
                                 sizeof (rnd));
-    ds = TALER_CRYPTO_helper_rsa_sign (dh,
+    ec = TALER_CRYPTO_helper_rsa_sign (dh,
                                        &rnd,
                                        "Hello",
                                        strlen ("Hello"),
-                                       &ec);
+                                       &ds);
     if (TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN != ec)
     {
       if (TALER_EC_NONE == ec)
@@ -485,14 +485,14 @@ perf_signing (struct TALER_CRYPTO_RsaDenominationHelper *dh,
           struct GNUNET_TIME_Absolute start = GNUNET_TIME_absolute_get ();
           struct GNUNET_TIME_Relative delay;
 
-          ds = TALER_CRYPTO_helper_rsa_sign (dh,
+          ec = TALER_CRYPTO_helper_rsa_sign (dh,
                                              &keys[i].h_rsa,
                                              pd.blinded_planchet.details.
                                              rsa_blinded_planchet.blinded_msg,
                                              pd.blinded_planchet.details.
                                              rsa_blinded_planchet.
                                              blinded_msg_size,
-                                             &ec);
+                                             &ds);
           if (TALER_EC_NONE != ec)
             break;
           delay = GNUNET_TIME_absolute_get_duration (start);