From 383f3eb850a2b557c3ae69e791e08420817d78b8 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 28 Sep 2015 22:56:20 +0200
Subject: [PATCH] properly check contract hash, instead of just computing it
 twice

---
 src/mint/taler-mint-httpd_deposit.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/mint/taler-mint-httpd_deposit.c b/src/mint/taler-mint-httpd_deposit.c
index 39696f475..f62e9ed3c 100644
--- a/src/mint/taler-mint-httpd_deposit.c
+++ b/src/mint/taler-mint-httpd_deposit.c
@@ -136,6 +136,7 @@ parse_and_handle_deposit_request (struct MHD_Connection *connection,
   struct TALER_MINTDB_Deposit deposit;
   struct TALER_MINTDB_DenominationKeyIssueInformation *dki;
   struct TMH_KS_StateHandle *ks;
+  struct GNUNET_HashCode my_h_wire;
   struct TMH_PARSE_FieldSpecification spec[] = {
     TMH_PARSE_member_denomination_public_key ("denom_pub", &deposit.coin.denom_pub),
     TMH_PARSE_member_denomination_signature ("ub_sig", &deposit.coin.denom_sig),
@@ -169,13 +170,22 @@ parse_and_handle_deposit_request (struct MHD_Connection *connection,
   }
   if (GNUNET_OK !=
       TALER_hash_json (wire,
-                       &deposit.h_wire))
+                       &my_h_wire))
   {
     TALER_LOG_WARNING ("Failed to parse JSON wire format specification for /deposit request\n");
     TMH_PARSE_release_data (spec);
     return TMH_RESPONSE_reply_arg_invalid (connection,
                                            "wire");
   }
+  if (0 != memcmp (&deposit.h_wire,
+		   &my_h_wire,
+		   sizeof (struct GNUNET_HashCode)))
+  {
+    /* Client hashed contract differently than we did, reject */
+    TMH_PARSE_release_data (spec);
+    return TMH_RESPONSE_reply_arg_invalid (connection,
+                                           "H_wire");
+  }
   ks = TMH_KS_acquire ();
   dki = TMH_KS_denomination_key_lookup (ks,
                                         &deposit.coin.denom_pub,