implementing #3632: generate proof of insufficient funds by converting transaction history to JSON

8 files changed, 223 insertions, 67 deletions

diff --git a/src/include/taler_json_lib.h b/src/include/taler_json_lib.h
index f0ae923f4..2b9d51875 100644
--- a/src/include/taler_json_lib.h
+++ b/src/include/taler_json_lib.h
@@ -60,8 +60,20 @@ TALER_JSON_from_abs (struct GNUNET_TIME_Absolute stamp);
  * @return the JSON reporesentation of the signature with purpose
  */
 json_t *
-TALER_JSON_from_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
-                     const struct GNUNET_CRYPTO_EddsaSignature *signature);
+TALER_JSON_from_eddsa_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+                           const struct GNUNET_CRYPTO_EddsaSignature *signature);
+
+
+/**
+ * Convert a signature (with purpose) to a JSON object representation.
+ *
+ * @param purpose purpose of the signature
+ * @param signature the signature
+ * @return the JSON reporesentation of the signature with purpose
+ */
+json_t *
+TALER_JSON_from_ecdsa_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+                           const struct GNUNET_CRYPTO_EcdsaSignature *signature);
 
 
 /**
@@ -77,6 +89,17 @@ TALER_JSON_from_data (const void *data, size_t size);
 
 
 /**
+ * Convert binary hash to a JSON string with the base32crockford
+ * encoding.
+ *
+ * @param hc binary data
+ * @return json string that encodes @a hc
+ */
+json_t *
+TALER_JSON_from_hash (const struct GNUNET_HashCode *hc);
+
+
+/**
  * Parse given JSON object to Amount
  *
  * @param json the json object representing Amount
@@ -119,7 +142,8 @@ TALER_JSON_to_data (json_t *json,
  * @return 1 if correctly formatted; 0 if not
  */
 int
-TALER_JSON_validate_wireformat (const char *type, json_t *wire);
+TALER_JSON_validate_wireformat (const char *type,
+                                json_t *wire);
 
 
 #endif /* TALER_JSON_LIB_H_ */
diff --git a/src/include/taler_signatures.h b/src/include/taler_signatures.h
index 905d1ed23..8984165e6 100644
--- a/src/include/taler_signatures.h
+++ b/src/include/taler_signatures.h
@@ -266,83 +266,120 @@ struct RefreshMeltResponseSignatureBody
 };
 
 
-
-
-
 /**
- * FIXME
+ * Message signed by a coin to indicate that the coin should
+ * be melted.
  */
-struct TALER_MINT_SignKeyIssue
+struct RefreshMeltSignatureBody
 {
-  struct GNUNET_CRYPTO_EddsaSignature signature;
+  /**
+   * Purpose is #TALER_SIGNATURE_REFRESH_MELT.
+   */
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  struct GNUNET_CRYPTO_EddsaPublicKey master_pub;
-  struct GNUNET_TIME_AbsoluteNBO start;
-  struct GNUNET_TIME_AbsoluteNBO expire;
-  struct GNUNET_CRYPTO_EddsaPublicKey signkey_pub;
+
+  /**
+   * Which melting operation should the coin become a part of.
+   */
+  struct GNUNET_HashCode melt_hash;
+
+  /**
+   * How much of the value of the coin should be melted?
+   * This amount includes the fees, so the final amount contributed
+   * to the melt is this value minus the fee for melting the coin.
+   */
+  struct TALER_AmountNBO amount;
 };
 
 
 /**
- * FIXME
+ * Message signed during melting committing the client to the
+ * hashed inputs.
  */
-struct TALER_MINT_DenomKeyIssue
+struct RefreshCommitSignatureBody
 {
-  struct GNUNET_CRYPTO_EddsaSignature signature;
+  /**
+   * Purpose is #TALER_SIGNATURE_REFRESH_COMMIT.
+   */
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  struct GNUNET_CRYPTO_EddsaPublicKey master;
-  struct GNUNET_TIME_AbsoluteNBO start;
-  struct GNUNET_TIME_AbsoluteNBO expire_withdraw;
-  struct GNUNET_TIME_AbsoluteNBO expire_spend;
-  // FIXME: does not work like this:
-  struct GNUNET_CRYPTO_rsa_PublicKey * denom_pub;
-  struct TALER_AmountNBO value;
-  struct TALER_AmountNBO fee_withdraw;
-  struct TALER_AmountNBO fee_deposit;
-  struct TALER_AmountNBO fee_refresh;
+
+  /**
+   * Session state the client commits itself to.
+   */
+  struct GNUNET_HashCode commit_hash;
 };
 
 
 /**
- * FIXME
+ * Message signed by the mint, committing it to a particular
+ * index to not be revealed during the refresh.
  */
-struct RefreshMeltSignatureBody
+struct RefreshCommitResponseSignatureBody
 {
+  /**
+   * Purpose is #TALER_SIGNATURE_REFRESH_MELT_RESPONSE.
+   */
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  struct GNUNET_HashCode melt_hash;
+
+  /**
+   * Index that the client will not have to reveal.
+   */
+  uint16_t noreveal_index GNUNET_PACKED;
 };
 
+
 /**
- * FIXME
+ * Message signed by the client requesting the final
+ * result of the melting operation.
  */
-struct RefreshCommitSignatureBody
+struct RefreshMeltConfirmSignRequestBody
 {
+  /**
+   * Purpose is #TALER_SIGNATURE_REFRESH_MELT_CONFIRM.
+   */
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  struct GNUNET_HashCode commit_hash;
+
+  /**
+   * FIXME.
+   */
+  struct GNUNET_CRYPTO_EddsaPublicKey session_pub;
 };
 
 
 /**
  * FIXME
  */
-struct RefreshCommitResponseSignatureBody
+struct TALER_MINT_SignKeyIssue
 {
+  struct GNUNET_CRYPTO_EddsaSignature signature;
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  uint16_t noreveal_index;
+  struct GNUNET_CRYPTO_EddsaPublicKey master_pub;
+  struct GNUNET_TIME_AbsoluteNBO start;
+  struct GNUNET_TIME_AbsoluteNBO expire;
+  struct GNUNET_CRYPTO_EddsaPublicKey signkey_pub;
 };
 
 
-
 /**
  * FIXME
  */
-struct RefreshMeltConfirmSignRequestBody
+struct TALER_MINT_DenomKeyIssue
 {
+  struct GNUNET_CRYPTO_EddsaSignature signature;
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
-  struct GNUNET_CRYPTO_EddsaPublicKey session_pub;
+  struct GNUNET_CRYPTO_EddsaPublicKey master;
+  struct GNUNET_TIME_AbsoluteNBO start;
+  struct GNUNET_TIME_AbsoluteNBO expire_withdraw;
+  struct GNUNET_TIME_AbsoluteNBO expire_spend;
+  // FIXME: does not work like this:
+  struct GNUNET_CRYPTO_rsa_PublicKey * denom_pub;
+  struct TALER_AmountNBO value;
+  struct TALER_AmountNBO fee_withdraw;
+  struct TALER_AmountNBO fee_deposit;
+  struct TALER_AmountNBO fee_refresh;
 };
 
 
+
 GNUNET_NETWORK_STRUCT_END
 
 #endif
diff --git a/src/mint/mint_db.h b/src/mint/mint_db.h
index 74f0c2d14..c3a300a57 100644
--- a/src/mint/mint_db.h
+++ b/src/mint/mint_db.h
@@ -222,8 +222,6 @@ TALER_MINT_DB_reserves_in_insert (PGconn *db,
                                   const struct TALER_Amount balance,
                                   const struct GNUNET_TIME_Absolute expiry);
 
-/* FIXME: need call to convert CollectableBlindcoin to JSON (#3527) */
-
 
 /**
  * Locate the response for a /withdraw request under the
@@ -529,10 +527,8 @@ TALER_MINT_DB_update_refresh_session (PGconn *db_conn,
 
 /**
  * Specification for coin in a /refresh/melt operation.
- * FIXME: same as `struct MeltDetails`, and not by accident!
- * We should merge the structs!
  */
-struct RefreshMelt /* FIXME: name to make it clearer this is about ONE coin! */
+struct RefreshMelt
 {
   /**
    * Information about the coin that is being melted.
@@ -545,7 +541,14 @@ struct RefreshMelt /* FIXME: name to make it clearer this is about ONE coin! */
   struct GNUNET_CRYPTO_EcdsaSignature coin_sig;
 
   /**
+   * Which melting operation should the coin become a part of.
+   */
+  struct GNUNET_HashCode melt_hash;
+
+  /**
    * How much value is being melted?
+   * This amount includes the fees, so the final amount contributed
+   * to the melt is this value minus the fee for melting the coin.
    */
   struct TALER_Amount amount;
 
diff --git a/src/mint/taler-mint-httpd_db.c b/src/mint/taler-mint-httpd_db.c
index e3f7b754c..ed9119313 100644
--- a/src/mint/taler-mint-httpd_db.c
+++ b/src/mint/taler-mint-httpd_db.c
@@ -22,10 +22,6 @@
  * - actually abstract DB implementation (i.e. via plugin logic)
  *   (this file should remain largely unchanged with the exception
  *    of the PQ-specific DB handle types)
- * - /refresh/link:
- *   + check low-level API
- *   + separate DB logic from response generation
- *   + check for leaks
  */
 #include "platform.h"
 #include <pthread.h>
@@ -354,8 +350,8 @@ TALER_MINT_db_execute_withdraw_sign (struct MHD_Connection *connection,
       break;
     }
   }
-
-  /* FIXME: good place to assert deposit_total > withdraw_total... */
+  GNUNET_break (0 > TALER_amount_cmp (withdraw_total,
+                                      deposit_total));
   balance = TALER_amount_subtract (deposit_total,
                                    withdraw_total);
   if (0 < TALER_amount_cmp (amount_required,
@@ -382,8 +378,6 @@ TALER_MINT_db_execute_withdraw_sign (struct MHD_Connection *connection,
     return TALER_MINT_reply_internal_error (connection,
                                             "Internal error");
   }
-
-  // FIXME: can we avoid the cast?
   collectable.denom_pub = (struct GNUNET_CRYPTO_rsa_PublicKey *) denomination_pub;
   collectable.sig = sig;
   collectable.reserve_pub = *reserve;
@@ -430,6 +424,7 @@ static int
 refresh_accept_melts (struct MHD_Connection *connection,
                       PGconn *db_conn,
                       const struct MintKeyState *key_state,
+                      const struct GNUNET_HashCode *melt_hash,
                       const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub,
                       const struct TALER_CoinPublicInfo *coin_public_info,
                       const struct MeltDetails *coin_details,
@@ -474,6 +469,7 @@ refresh_accept_melts (struct MHD_Connection *connection,
 
   melt.coin = *coin_public_info;
   melt.coin_sig = coin_details->melt_sig;
+  melt.melt_hash = *melt_hash;
   melt.amount = coin_details->melt_amount;
   if (GNUNET_OK !=
       TALER_MINT_DB_insert_refresh_melt (db_conn,
@@ -496,6 +492,7 @@ refresh_accept_melts (struct MHD_Connection *connection,
  * melted and confirm the melting operation to the client.
  *
  * @param connection the MHD connection to handle
+ * @param melt_hash hash code of the session the coins are melted into
  * @param refresh_session_pub public key of the refresh session
  * @param client_signature signature of the client (matching @a refresh_session_pub)
  *         over the melting request
@@ -508,6 +505,7 @@ refresh_accept_melts (struct MHD_Connection *connection,
  */
 int
 TALER_MINT_db_execute_refresh_melt (struct MHD_Connection *connection,
+                                    const struct GNUNET_HashCode *melt_hash,
                                     const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
                                     const struct GNUNET_CRYPTO_EddsaSignature *client_signature,
                                     unsigned int num_new_denoms,
@@ -558,6 +556,7 @@ TALER_MINT_db_execute_refresh_melt (struct MHD_Connection *connection,
         (res = refresh_accept_melts (connection,
                                      db_conn,
                                      key_state,
+                                     melt_hash,
                                      refresh_session_pub,
                                      &coin_public_infos[i],
                                      &coin_melt_details[i],
diff --git a/src/mint/taler-mint-httpd_db.h b/src/mint/taler-mint-httpd_db.h
index b945a7f65..dcd5e6fa0 100644
--- a/src/mint/taler-mint-httpd_db.h
+++ b/src/mint/taler-mint-httpd_db.h
@@ -93,7 +93,8 @@ struct MeltDetails
 
   /**
    * How much of the coin's value did the client allow to be melted?
-   * (FIXME: are the fees included here!?)
+   * This amount includes the fees, so the final amount contributed
+   * to the melt is this value minus the fee for melting the coin.
    */
   struct TALER_Amount melt_amount;
 };
@@ -107,6 +108,7 @@ struct MeltDetails
  * melted and confirm the melting operation to the client.
  *
  * @param connection the MHD connection to handle
+ * @param melt_hash hash code of the session the coins are melted into
  * @param refresh_session_pub public key of the refresh session
  * @param client_signature signature of the client (matching @a refresh_session_pub)
  *         over the melting request
@@ -119,6 +121,7 @@ struct MeltDetails
  */
 int
 TALER_MINT_db_execute_refresh_melt (struct MHD_Connection *connection,
+                                    const struct GNUNET_HashCode *melt_hash,
                                     const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
                                     const struct GNUNET_CRYPTO_EddsaSignature *client_signature,
                                     unsigned int num_new_denoms,
diff --git a/src/mint/taler-mint-httpd_refresh.c b/src/mint/taler-mint-httpd_refresh.c
index cae001acc..5625dc8c7 100644
--- a/src/mint/taler-mint-httpd_refresh.c
+++ b/src/mint/taler-mint-httpd_refresh.c
@@ -195,9 +195,10 @@ handle_refresh_melt_binary (struct MHD_Connection *connection,
   GNUNET_CRYPTO_hash_context_finish (hash_context,
                                      &melt_hash);
 
-  body.melt_hash = melt_hash;
   body.purpose.purpose = htonl (TALER_SIGNATURE_REFRESH_MELT);
   body.purpose.size = htonl (sizeof (struct RefreshMeltSignatureBody));
+  body.melt_hash = melt_hash;
+  body.amount = TALER_amount_hton (coin_melt_details->melt_amount);
 
   if (GNUNET_OK !=
       (res = request_json_check_signature (connection,
@@ -247,6 +248,7 @@ handle_refresh_melt_binary (struct MHD_Connection *connection,
 
   /* FIXME: we must also store the signature over the melt! (#3635) */
   return TALER_MINT_db_execute_refresh_melt (connection,
+                                             &melt_hash,
                                              refresh_session_pub,
                                              NULL, /* FIXME: #3635! */
                                              num_new_denoms,
diff --git a/src/mint/taler-mint-httpd_responses.c b/src/mint/taler-mint-httpd_responses.c
index 77cdb4078..ec8fdc03b 100644
--- a/src/mint/taler-mint-httpd_responses.c
+++ b/src/mint/taler-mint-httpd_responses.c
@@ -305,7 +305,7 @@ TALER_MINT_reply_deposit_success (struct MHD_Connection *connection,
   dc.merchant = *merchant;
   TALER_MINT_keys_sign (&dc.purpose,
                         &sig);
-  sig_json = TALER_JSON_from_sig (&dc.purpose, &sig);
+  sig_json = TALER_JSON_from_eddsa_sig (&dc.purpose, &sig);
   ret = TALER_MINT_reply_json_pack (connection,
                                     MHD_HTTP_OK,
                                     "{s:s, s:o}",
@@ -332,28 +332,72 @@ TALER_MINT_reply_insufficient_funds (struct MHD_Connection *connection,
 {
   const struct TALER_MINT_DB_TransactionList *pos;
   int ret;
+  json_t *history;
+  json_t *transaction;
+  const char *type;
+  struct TALER_Amount value;
 
-  // FIXME: implement properly! (#3632)
+  history = json_array ();
   for (pos = tl; NULL != pos; pos = pos->next)
   {
     switch (pos->type)
     {
     case TALER_MINT_DB_TT_DEPOSIT:
-      /* FIXME: add operation details to json reply */
-      break;
+      {
+        struct TALER_DepositRequest dr;
+        const struct Deposit *deposit = pos->details.deposit;
+
+        type = "deposit";
+        value = deposit->amount;
+        dr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_DEPOSIT);
+        dr.purpose.size = htonl (sizeof (struct TALER_DepositRequest));
+        dr.h_contract = deposit->h_contract;
+        dr.h_wire = deposit->h_wire;
+        dr.transaction_id = GNUNET_htonll (deposit->transaction_id);
+        dr.amount = TALER_amount_hton (deposit->amount);
+        dr.coin_pub = deposit->coin.coin_pub;
+        transaction = TALER_JSON_from_ecdsa_sig (&dr.purpose,
+                                                 &deposit->csig);
+        break;
+      }
     case TALER_MINT_DB_TT_REFRESH_MELT:
-      /* FIXME: add operation details to json reply */
+      {
+        struct RefreshMeltSignatureBody ms;
+        const struct RefreshMelt *melt = pos->details.melt;
+
+        type = "melt";
+        value = melt->amount;
+        ms.purpose.purpose = htonl (TALER_SIGNATURE_REFRESH_MELT);
+        ms.purpose.size = htonl (sizeof (struct RefreshMeltSignatureBody));
+        ms.melt_hash = melt->melt_hash;
+        ms.amount = TALER_amount_hton (melt->amount);
+        transaction = TALER_JSON_from_ecdsa_sig (&ms.purpose,
+                                                 &melt->coin_sig);
+      }
       break;
     case TALER_MINT_DB_TT_LOCK:
-      /* FIXME: add operation details to json reply */
-      break;
+      {
+        type = "lock";
+        value = pos->details.lock->amount;
+        transaction = NULL;
+        GNUNET_break (0); /* #3625: Lock NOT implemented! */
+        break;
+      }
+    default:
+      GNUNET_assert (0);
     }
+    json_array_append_new (history,
+                           json_pack ("{s:s, s:o}",
+                                      "type", type,
+                                      "amount", TALER_JSON_from_amount (value),
+                                      "signature", transaction));
   }
 
   ret = TALER_MINT_reply_json_pack (connection,
                                     MHD_HTTP_FORBIDDEN,
-                                    "{s:s}",
-                                    "error", "insufficient funds");
+                                    "{s:s, s:o}",
+                                    "error", "insufficient funds",
+                                    "history", history);
   return ret;
 }
 
@@ -517,7 +561,7 @@ TALER_MINT_reply_withdraw_sign_success (struct MHD_Connection *connection,
   char *sig_buf;
   int ret;
 
-  /* FIXME: use TALER_JSON_from_sig here instead!? */
+  /* FIXME: use TALER_JSON_from_eddsa_sig here instead!? */
   sig_buf_size = GNUNET_CRYPTO_rsa_signature_encode (collectable->sig,
                                                      &sig_buf);
   sig_json = TALER_JSON_from_data (sig_buf,
@@ -561,7 +605,7 @@ TALER_MINT_reply_refresh_melt_success (struct MHD_Connection *connection,
   body.kappa = htonl (kappa);
   TALER_MINT_keys_sign (&body.purpose,
                         &sig);
-  sig_json = TALER_JSON_from_sig (&body.purpose, &sig);
+  sig_json = TALER_JSON_from_eddsa_sig (&body.purpose, &sig);
   ret = TALER_MINT_reply_json_pack (connection,
                                     MHD_HTTP_OK,
                                     "{s:o, s:i}",
@@ -595,7 +639,7 @@ TALER_MINT_reply_refresh_commit_success (struct MHD_Connection *connection,
   body.noreveal_index = htons (refresh_session->noreveal_index);
   TALER_MINT_keys_sign (&body.purpose,
                         &sig);
-  sig_json = TALER_JSON_from_sig (&body.purpose, &sig);
+  sig_json = TALER_JSON_from_eddsa_sig (&body.purpose, &sig);
   GNUNET_assert (NULL != sig_json);
   ret = TALER_MINT_reply_json_pack (connection,
                                      MHD_HTTP_OK,
diff --git a/src/util/json.c b/src/util/json.c
index 02591d7bf..38f459200 100644
--- a/src/util/json.c
+++ b/src/util/json.c
@@ -90,8 +90,8 @@ TALER_JSON_from_abs (struct GNUNET_TIME_Absolute stamp)
  * @return the JSON reporesentation of the signature with purpose
  */
 json_t *
-TALER_JSON_from_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
-                     const struct GNUNET_CRYPTO_EddsaSignature *signature)
+TALER_JSON_from_eddsa_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+                           const struct GNUNET_CRYPTO_EddsaSignature *signature)
 {
   json_t *root;
   json_t *el;
@@ -106,7 +106,37 @@ TALER_JSON_from_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
 
   el = TALER_JSON_from_data (signature,
                              sizeof (struct GNUNET_CRYPTO_EddsaSignature));
-  json_object_set_new (root, "sig", el);
+  json_object_set_new (root, "eddsa-sig", el);
+
+  return root;
+}
+
+
+/**
+ * Convert a signature (with purpose) to a JSON object representation.
+ *
+ * @param purpose purpose of the signature
+ * @param signature the signature
+ * @return the JSON reporesentation of the signature with purpose
+ */
+json_t *
+TALER_JSON_from_ecdsa_sig (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+                           const struct GNUNET_CRYPTO_EcdsaSignature *signature)
+{
+  json_t *root;
+  json_t *el;
+
+  root = json_object ();
+
+  el = json_integer ((json_int_t) ntohl (purpose->size));
+  json_object_set_new (root, "size", el);
+
+  el = json_integer ((json_int_t) ntohl (purpose->purpose));
+  json_object_set_new (root, "purpose", el);
+
+  el = TALER_JSON_from_data (signature,
+                             sizeof (struct GNUNET_CRYPTO_EddsaSignature));
+  json_object_set_new (root, "ecdsa-sig", el);
 
   return root;
 }
@@ -134,6 +164,20 @@ TALER_JSON_from_data (const void *data, size_t size)
 
 
 /**
+ * Convert binary hash to a JSON string with the base32crockford
+ * encoding.
+ *
+ * @param hc binary data
+ * @return json string that encodes @a hc
+ */
+json_t *
+TALER_JSON_from_hash (const struct GNUNET_HashCode *hc)
+{
+  return TALER_JSON_from_data (hc, sizeof (struct GNUNET_HashCode));
+}
+
+
+/**
  * Parse given JSON object to Amount
  *
  * @param json the json object representing Amount