exchange/src/include/taler_error_codes.h

/*
  This file is part of TALER
  Copyright (C) 2016, 2017 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU General Public License as published by the Free Software
  Foundation; either version 3, or (at your option) any later version.

  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file taler_error_codes.h
 * @brief error codes returned by GNU Taler
 *
 * This file should define constants for error codes returned
 * in Taler APIs.  We use codes above 1000 to avoid any
 * confusing with HTTP status codes.  All constants have the
 * shared prefix "TALER_EC_" to indicate that they are error
 * codes.
 */
#ifndef TALER_ERROR_CODES_H
#define TALER_ERROR_CODES_H

/**
 * Enumeration with all possible Taler error codes.
 */
enum TALER_ErrorCode
{

  /**
   * Special code to indicate no error (or no "code" present).
   */
  TALER_EC_NONE = 0,

  /**
   * Special code to indicate that a non-integer error code was
   * returned in the JSON response.
   */
  TALER_EC_INVALID = 1,

  /**
   * The response we got from the server was not even in JSON format.
   */
  TALER_EC_INVALID_RESPONSE = 2,

  /**
   * Generic implementation error: this function was not yet implemented.
   */
  TALER_EC_NOT_IMPLEMENTED = 3,

  /**
   * Exchange is badly configured and thus cannot operate.
   */
  TALER_EC_EXCHANGE_BAD_CONFIGURATION = 4,

  /**
   * Internal assertion error.
   */
  TALER_EC_INTERNAL_INVARIANT_FAILURE = 5,

  /**
   * Operation timed out.
   */
  TALER_EC_TIMEOUT = 6,

  /**
   * Exchange failed to allocate memory for building JSON reply.
   */
  TALER_EC_JSON_ALLOCATION_FAILURE = 7,

  /* ********** generic error codes ************* */

  /**
   * The exchange failed to even just initialize its connection to the
   * database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DB_SETUP_FAILED = 1001,

  /**
   * The exchange encountered an error event to just start
   * the database transaction.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DB_START_FAILED = 1002,

  /**
   * The exchange encountered an error event to commit
   * the database transaction (hard, unrecoverable error).
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DB_COMMIT_FAILED_HARD = 1003,

  /**
   * The exchange encountered an error event to commit
   * the database transaction, even after repeatedly
   * retrying it there was always a conflicting transaction.
   * (This indicates a repeated serialization error; should
   * only happen if some client maliciously tries to create
   * conflicting concurrent transactions.)
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DB_COMMIT_FAILED_ON_RETRY = 1004,

    /**
   * The exchange had insufficient memory to parse the request. This
   * response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PARSER_OUT_OF_MEMORY = 1005,

  /**
   * The JSON in the client's request to the exchange was malformed.
   * (Generic parse error).
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_JSON_INVALID = 1006,

  /**
   * The JSON in the client's request to the exchange was malformed.
   * Details about the location of the parse error are provided.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_JSON_INVALID_WITH_DETAILS = 1007,

  /**
   * A required parameter in the request to the exchange was missing.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PARAMETER_MISSING = 1008,

  /**
   * A parameter in the request to the exchange was malformed.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PARAMETER_MALFORMED = 1009,

  /**
   * The exchange failed to obtain the transaction history of the
   * given coin from the database while generating an insufficient
   * funds errors.  This can happen during /deposit or /payback requests.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_COIN_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS = 1010,

  /**
   * Internal logic error.  Some server-side function
   * failed that really should not.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_INTERNAL_LOGIC_ERROR = 1011,



  /* ********** request-specific error codes ************* */

  /**
   * The given reserve does not have sufficient funds to admit the
   * requested withdraw operation at this time.  The response includes
   * the current "balance" of the reserve as well as the transaction
   * "history" that lead to this balance.  This response is provided
   * with HTTP status code MHD_HTTP_FORBIDDEN.
   */
  TALER_EC_WITHDRAW_INSUFFICIENT_FUNDS = 1100,

  /**
   * The exchange has no information about the "reserve_pub" that
   * was given.
   * This response is provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_WITHDRAW_RESERVE_UNKNOWN = 1101,

  /**
   * The amount to withdraw together with the fee exceeds the
   * numeric range for Taler amounts.  This is not a client
   * failure, as the coin value and fees come from the exchange's
   * configuration.
   * This response is provided with HTTP status code MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_AMOUNT_FEE_OVERFLOW = 1102,

  /**
   * All of the deposited amounts into this reserve total up to a
   * value that is too big for the numeric range for Taler amounts.
   * This is not a client failure, as the transaction history comes
   * from the exchange's configuration.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_AMOUNT_DEPOSITS_OVERFLOW = 1103,

  /**
   * For one of the historic withdrawals from this reserve, the
   * exchange could not find the denomination key.
   * This is not a client failure, as the transaction history comes
   * from the exchange's configuration.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_HISTORIC_DENOMINATION_KEY_NOT_FOUND = 1104,

  /**
   * All of the withdrawals from reserve total up to a
   * value that is too big for the numeric range for Taler amounts.
   * This is not a client failure, as the transaction history comes
   * from the exchange's configuration.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_AMOUNT_WITHDRAWALS_OVERFLOW = 1105,

  /**
   * The exchange somehow knows about this reserve, but there seem to
   * have been no wire transfers made.  This is not a client failure,
   * as this is a database consistency issue of the exchange.  This
   * response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_RESERVE_WITHOUT_WIRE_TRANSFER = 1106,

  /**
   * The exchange failed to create the signature using the
   * denomination key.  This response is provided with HTTP status
   * code MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_SIGNATURE_FAILED = 1107,

  /**
   * The exchange failed to store the withdraw operation in its
   * database.  This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_DB_STORE_ERROR = 1108,

  /**
   * The exchange failed to check against historic withdraw data from
   * database (as part of ensuring the idempotency of the operation).
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_WITHDRAW_DB_FETCH_ERROR = 1109,

  /**
   * The exchange is not aware of the denomination key
   * the wallet requested for the withdrawal.
   * This response is provided
   * with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_WITHDRAW_DENOMINATION_KEY_NOT_FOUND = 1110,

  /**
   * The signature of the reserve is not valid.  This response is
   * provided with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_WITHDRAW_RESERVE_SIGNATURE_INVALID = 1111,

  /**
   * The exchange failed to obtain the transaction history of the
   * given reserve from the database while generating an insufficient
   * funds error.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_WITHDRAW_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS = 1112,

  /**
   * When computing the reserve history, we ended up with a negative
   * overall balance, which should be impossible.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_WITHDRAW_RESERVE_HISTORY_IMPOSSIBLE = 1113,

  /**
   * The exchange failed to obtain the transaction history of the
   * given reserve from the database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_RESERVE_STATUS_DB_ERROR = 1150,


  /**
   * The respective coin did not have sufficient residual value
   * for the /deposit operation (i.e. due to double spending).
   * The "history" in the respose provides the transaction history
   * of the coin proving this fact.  This response is provided
   * with HTTP status code MHD_HTTP_FORBIDDEN.
   */
  TALER_EC_DEPOSIT_INSUFFICIENT_FUNDS = 1200,

  /**
   * The exchange failed to obtain the transaction history of the
   * given coin from the database (this does not happen merely because
   * the coin is seen by the exchange for the first time).
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DEPOSIT_HISTORY_DB_ERROR = 1201,

  /**
   * The exchange failed to store the /depost information in the
   * database.  This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DEPOSIT_STORE_DB_ERROR = 1202,

  /**
   * The exchange database is unaware of the denomination key that
   * signed the coin (however, the exchange process is; this is not
   * supposed to happen; it can happen if someone decides to purge the
   * DB behind the back of the exchange process).  Hence the deposit
   * is being refused.  This response is provided with HTTP status
   * code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_DEPOSIT_DB_DENOMINATION_KEY_UNKNOWN = 1203,

  /**
   * The exchange database is unaware of the denomination key that
   * signed the coin (however, the exchange process is; this is not
   * supposed to happen; it can happen if someone decides to purge the
   * DB behind the back of the exchange process).  Hence the deposit
   * is being refused.  This response is provided with HTTP status
   * code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_DEPOSIT_DENOMINATION_KEY_UNKNOWN = 1204,

  /**
   * The signature of the coin is not valid.  This response is
   * provided with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_COIN_SIGNATURE_INVALID = 1205,

  /**
   * The signature of the denomination key over the coin is not valid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_DENOMINATION_SIGNATURE_INVALID = 1206,

  /**
   * The stated value of the coin after the deposit fee is subtracted
   * would be negative.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_NEGATIVE_VALUE_AFTER_FEE = 1207,

  /**
   * The stated refund deadline is after the wire deadline.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_REFUND_DEADLINE_AFTER_WIRE_DEADLINE = 1208,

  /**
   * The exchange does not recognize the validity of or support the
   * given wire format type.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_TYPE = 1209,

  /**
   * The exchange failed to canonicalize and hash the given wire format.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_JSON = 1210,

  /**
   * The hash of the given wire address does not match the hash
   * specified in the proposal data.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_CONTRACT_HASH_CONFLICT = 1211,

  /**
   * The exchange detected that the given account number
   * is invalid for the selected wire format type.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_ACCOUNT_NUMBER = 1213,

  /**
   * The signature over the given wire details is invalid.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_SIGNATURE = 1214,

  /**
   * The bank specified in the wire transfer format is not supported
   * by this exchange.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_BANK = 1215,

  /**
   * No wire format type was specified in the JSON wire format
   * details.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_TYPE_MISSING = 1216,

  /**
   * The given wire format type is not supported by this
   * exchange.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_TYPE_UNSUPPORTED = 1217,

  /**
   * Timestamp included in deposit permission is intolerably far off
   * with respect to the clock of the exchange.
   */
  TALER_EC_DEPOSIT_INVALID_TIMESTAMP = 1218,


  /**
   * The respective coin did not have sufficient residual value
   * for the /refresh/melt operation.  The "history" in this
   * response provdes the "residual_value" of the coin, which may
   * be less than its "original_value".  This response is provided
   * with HTTP status code MHD_HTTP_FORBIDDEN.
   */
  TALER_EC_REFRESH_MELT_INSUFFICIENT_FUNDS = 1300,

  /**
   * The exchange is unaware of the denomination key that was
   * used to sign the melted coin.  This response is provided
   * with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_REFRESH_MELT_DENOMINATION_KEY_NOT_FOUND = 1301,

  /**
   * The exchange had an internal error reconstructing the
   * transaction history of the coin that was being melted.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFRESH_MELT_COIN_HISTORY_COMPUTATION_FAILED = 1302,

  /**
   * The exchange failed to check against historic melt data from
   * database (as part of ensuring the idempotency of the operation).
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_MELT_DB_FETCH_ERROR = 1303,

  /**
   * The exchange failed to store session data in the
   * database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_MELT_DB_STORE_SESSION_ERROR = 1304,

  /**
   * The exchange encountered melt fees exceeding the melted
   * coin's contribution.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_MELT_FEES_EXCEED_CONTRIBUTION = 1305,

  /**
   * The denomination key signature on the melted coin is invalid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_MELT_DENOMINATION_SIGNATURE_INVALID = 1306,

  /**
   * The signature made with the coin to be melted is invalid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_MELT_COIN_SIGNATURE_INVALID = 1307,

  /**
   * The exchange failed to obtain the transaction history of the
   * given coin from the database while generating an insufficient
   * funds errors.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFRESH_MELT_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS = 1308,


  /**
   * The provided transfer keys do not match up with the
   * original commitment.  Information about the original
   * commitment is included in the response.  This response is
   * provided with HTTP status code MHD_HTTP_CONFLICT.
   */
  TALER_EC_REFRESH_REVEAL_COMMITMENT_VIOLATION = 1350,

  /**
   * Failed to produce the blinded signatures over the coins
   * to be returned.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_REVEAL_SIGNING_ERROR = 1351,

  /**
   * The exchange is unaware of the refresh sessino specified in
   * the request.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_SESSION_UNKNOWN = 1352,

  /**
   * The exchange failed to retrieve valid session data from the
   * database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_REVEAL_DB_FETCH_SESSION_ERROR = 1353,

  /**
   * The exchange failed to retrieve previously revealed data from the
   * database.  This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_REVEAL_DB_FETCH_REVEAL_ERROR = 1354,

  /**
   * The exchange failed to retrieve commitment data from the
   * database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_ERROR.
   */
  TALER_EC_REFRESH_REVEAL_DB_COMMIT_ERROR = 1355,

  /**
   * The size of the cut-and-choose dimension of the
   * private transfer keys request does not match #TALER_CNC_KAPPA - 1.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_CNC_TRANSFER_ARRAY_SIZE_INVALID = 1356,

  /**
   * The number of coins to be created in refresh exceeds the limits
   * of the exchange.
   * private transfer keys request does not match #TALER_CNC_KAPPA - 1.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_NEW_DENOMS_ARRAY_SIZE_EXCESSIVE = 1357,

  /**
   * The number of envelopes given does not match the number
   * of denomination keys given.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_NEW_DENOMS_ARRAY_SIZE_MISSMATCH = 1358,

  /**
   * The exchange encountered a numeric overflow totaling up
   * the cost for the refresh operation.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFRESH_REVEAL_COST_CALCULATION_OVERFLOW = 1359,

  /**
   * The exchange's cost calculation shows that the melt amount
   * is below the costs of the transaction.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_AMOUNT_INSUFFICIENT = 1360,

  /**
   * The exchange is unaware of the denomination key that was
   * requested for one of the fresh coins.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFRESH_REVEAL_FRESH_DENOMINATION_KEY_NOT_FOUND = 1361,


  /**
   * The coin specified in the link request is unknown to the exchange.
   * This response is provided with HTTP status code
   * MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_REFRESH_LINK_COIN_UNKNOWN = 1400,


  /**
   * The exchange knows literally nothing about the coin we were asked
   * to refund. But without a transaction history, we cannot issue a
   * refund.  This is kind-of OK, the owner should just refresh it
   * directly without executing the refund.  This response is provided
   * with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_REFUND_COIN_NOT_FOUND = 1500,

  /**
   * We could not process the refund request as the coin's transaction
   * history does not permit the requested refund at this time.  The
   * "history" in the response proves this.  This response is provided
   * with HTTP status code MHD_HTTP_CONFLICT.
   */
  TALER_EC_REFUND_CONFLICT = 1501,

  /**
   * The exchange knows about the coin we were asked to refund, but
   * not about the specific /deposit operation.  Hence, we cannot
   * issue a refund (as we do not know if this merchant public key is
   * authorized to do a refund).  This response is provided with HTTP
   * status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_REFUND_DEPOSIT_NOT_FOUND = 1503,

  /**
   * The currency specified for the refund is different from
   * the currency of the coin.  This response is provided with HTTP
   * status code MHD_HTTP_PRECONDITION_FAILED.
   */
  TALER_EC_REFUND_CURRENCY_MISSMATCH = 1504,

  /**
   * When we tried to check if we already paid out the coin, the
   * exchange's database suddenly disagreed with data it previously
   * provided (internal inconsistency).
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFUND_DB_INCONSISTENT = 1505,

  /**
   * The exchange can no longer refund the customer/coin as the
   * money was already transferred (paid out) to the merchant.
   * (It should be past the refund deadline.)
   * This response is provided with HTTP status code
   * MHD_HTTP_GONE.
   */
  TALER_EC_REFUND_MERCHANT_ALREADY_PAID = 1506,

  /**
   * The amount the exchange was asked to refund exceeds
   * (with fees) the total amount of the deposit (including fees).
   * This response is provided with HTTP status code
   * MHD_HTTP_PRECONDITION_FAILED.
   */
  TALER_EC_REFUND_INSUFFICIENT_FUNDS = 1507,

  /**
   * The exchange failed to recover information about the
   * denomination key of the refunded coin (even though it
   * recognizes the key).  Hence it could not check the fee
   * strucutre.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFUND_DENOMINATION_KEY_NOT_FOUND = 1508,

  /**
   * The refund fee specified for the request is lower than
   * the refund fee charged by the exchange for the given
   * denomination key of the refunded coin.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFUND_FEE_TOO_LOW = 1509,

  /**
   * The exchange failed to store the refund information to
   * its database.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_REFUND_STORE_DB_ERROR = 1510,

  /**
   * The refund fee is specified in a different currency
   * than the refund amount.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFUND_FEE_CURRENCY_MISSMATCH = 1511,

  /**
   * The refunded amount is smaller than the refund fee,
   * which would result in a negative refund.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFUND_FEE_ABOVE_AMOUNT = 1512,

  /**
   * The signature of the merchant is invalid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_REFUND_MERCHANT_SIGNATURE_INVALID = 1513,


  /**
   * The wire format specified in the "sender_account_details"
   * is not understood or not supported by this exchange.
   * Returned with an HTTP status code of MHD_HTTP_NOT_FOUND.
   * (As we did not find an interpretation of the wire format.)
   */
  TALER_EC_ADMIN_ADD_INCOMING_WIREFORMAT_UNSUPPORTED = 1600,

  /**
   * The currency specified in the "amount" parameter is not
   * supported by this exhange.  Returned with an HTTP status
   * code of MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_ADMIN_ADD_INCOMING_CURRENCY_UNSUPPORTED = 1601,

  /**
   * The exchange failed to store information about the incoming
   * transfer in its database.  This response is provided with HTTP
   * status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_ADMIN_ADD_INCOMING_DB_STORE = 1602,

  /**
   * The exchange encountered an error (that is not about not finding
   * the wire transfer) trying to lookup a wire transfer identifier
   * in the database.  This response is provided with HTTP
   * status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_FETCH_FAILED = 1700,

  /**
   * The exchange found internally inconsistent data when resolving a
   * wire transfer identifier in the database.  This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_INCONSISTENT = 1701,

  /**
   * The exchange did not find information about the specified
   * wire transfer identifier in the database.  This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSFER_WTID_NOT_FOUND = 1702,

  /**
   * The exchange did not find information about the wire transfer
   * fees it charged. This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_WIRE_FEE_NOT_FOUND = 1703,

  /**
   * The exchange found a wire fee that was above the total transfer
   * value (and thus could not have been charged). This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_WIRE_FEE_INCONSISTENT = 1704,

  /**
   * The exchange found internally inconsistent fee data when
   * resolving a transaction in the database.  This
   * response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSACTION_DB_FEE_INCONSISTENT = 1800,

  /**
   * The exchange encountered an error (that is not about not finding
   * the transaction) trying to lookup a transaction
   * in the database.  This response is provided with HTTP
   * status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSACTION_DB_FETCH_FAILED = 1801,

  /**
   * The exchange did not find information about the specified
   * transaction in the database.  This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSACTION_NOT_FOUND = 1802,

  /**
   * The exchange failed to identify the wire transfer of the
   * transaction (or information about the plan that it was supposed
   * to still happen in the future).  This response is provided with
   * HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSACTION_WTID_RESOLUTION_ERROR = 1803,

  /**
   * The signature of the merchant is invalid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_TRACK_TRANSACTION_MERCHANT_SIGNATURE_INVALID = 1804,

  /**
   * The given denomination key is not in the "payback" set of the
   * exchange right now.  This response is provided with an
   * HTTP status code of MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_PAYBACK_DENOMINATION_KEY_UNKNOWN = 1850,

  /**
   * The given coin signature is invalid for the request.
   * This response is provided with an
   * HTTP status code of MHD_HTTP_UNAUTHORIZED.
   */
  TALER_EC_PAYBACK_SIGNATURE_INVALID = 1851,

  /**
   * The signature of the denomination key over the coin is not valid.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAYBACK_DENOMINATION_SIGNATURE_INVALID = 1852,

  /**
   * The exchange failed to access its own database about reserves.
   * This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAYBACK_DB_FETCH_FAILED = 1853,

  /**
   * The exchange could not find the corresponding withdraw operation.
   * The request is denied.  This response is provided with an HTTP
   * status code of MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_PAYBACK_WITHDRAW_NOT_FOUND = 1854,

  /**
   * The exchange obtained an internally inconsistent transaction
   * history for the given coin. This response is provided with HTTP
   * status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAYBACK_HISTORY_DB_ERROR = 1855,

  /**
   * The exchange failed to store information about the payback to be
   * performed in the database. This response is provided with HTTP
   * status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAYBACK_DB_PUT_FAILED = 1856,

  /**
   * The coin's remaining balance is zero.  The request is denied.
   * This response is provided with an HTTP status code of
   * MHD_HTTP_FORBIDDEN.
   */
  TALER_EC_PAYBACK_COIN_BALANCE_ZERO = 1857,

  /**
   * The exchange failed to reproduce the coin's blinding.
   * This response is provided with an HTTP status code of
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAYBACK_BLINDING_FAILED = 1858,

  /**
   * The coin's remaining balance is zero.  The request is denied.
   * This response is provided with an HTTP status code of
   * MHD_HTTP_INTERNAL_SERVER_ERROR
   */
  TALER_EC_PAYBACK_COIN_BALANCE_NEGATIVE = 1857,

  /**
   * The "have" parameter was not a natural number.
   * This reponse is provied with an HTTP status code of
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_KEYS_HAVE_NOT_NUMERIC = 1900,


  /* *********** Merchant backend error codes ********* */

  /**
   * The backend could not find the merchant instance specified
   * in the request.   This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_CONTRACT_INSTANCE_UNKNOWN = 2000,

  /**
   * The exchange failed to provide a meaningful response
   * to a /deposit request.  This response is provided
   * with HTTP status code MHD_HTTP_SERVICE_UNAVAILABLE.
   */
  TALER_EC_PAY_EXCHANGE_FAILED = 2101,

  /**
   * The merchant failed to commit the exchanges' response to
   * a /deposit request to its database.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_DB_STORE_PAY_ERROR = 2102,

  /**
   * The specified exchange is not supported/trusted by
   * this merchant.  This response is provided
   * with HTTP status code MHD_HTTP_PRECONDITION_FAILED.
   */
  TALER_EC_PAY_EXCHANGE_REJECTED = 2103,

  /**
   * The denomination key used for payment is not listed among the
   * denomination keys of the exchange.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_DENOMINATION_KEY_NOT_FOUND = 2104,

  /**
   * The denomination key used for payment is not audited by an
   * auditor approved by the merchant.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_DENOMINATION_KEY_AUDITOR_FAILURE = 2105,

  /**
   * There was an integer overflow totaling up the amounts or
   * deposit fees in the payment.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_AMOUNT_OVERFLOW = 2106,

  /**
   * The deposit fees exceed the total value of the payment.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_FEES_EXCEED_PAYMENT = 2107,

  /**
   * After considering deposit fees, the payment is insufficient
   * to satisfy the required amount for the contract.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_PAYMENT_INSUFFICIENT_DUE_TO_FEES = 2108,

  /**
   * While the merchant is happy to cover all applicable deposit fees,
   * the payment is insufficient to satisfy the required amount for
   * the contract.  This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_PAYMENT_INSUFFICIENT = 2109,

  /**
   * The signature over the contract of one of the coins
   * was invalid. This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_COIN_SIGNATURE_INVALID = 2110,

  /**
   * We failed to contact the exchange for the /pay request.
   * This response is provided
   * with HTTP status code MHD_HTTP_SERVICE_UNAVAILABLE.
   */
  TALER_EC_PAY_EXCHANGE_TIMEOUT = 2111,

  /**
   * The backend could not find the merchant instance specified
   * in the request.   This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_PAY_INSTANCE_UNKNOWN = 2112,

  /**
   * The signature over the contract of the merchant
   * was invalid. This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_MERCHANT_SIGNATURE_INVALID = 2113,

  /**
   * The refund deadline was after the transfer deadline.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_REFUND_DEADLINE_PAST_WIRE_TRANSFER_DEADLINE = 2114,

  /**
   * The request fails to provide coins for the payment.
   * This response is provided with HTTP status code
   * MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_COINS_ARRAY_EMPTY = 2115,

  /**
   * The merchant failed to fetch the merchant's previous state with
   * respect to a /pay request from its database.  This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_DB_FETCH_PAY_ERROR = 2116,

  /**
   * The merchant failed to fetch the merchant's previous state with
   * respect to transactions from its database.  This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_DB_FETCH_TRANSACTION_ERROR = 2117,

  /**
   * The transaction ID was used for a conflicing transaction before.
   * This response is
   * provided with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_DB_TRANSACTION_ID_CONFLICT = 2118,

  /**
   * The merchant failed to store the merchant's state with
   * respect to the transaction in its database.  This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_DB_STORE_TRANSACTION_ERROR = 2119,

  /**
   * The exchange failed to provide a valid response to
   * the merchant's /keys request.
   * This response is provided
   * with HTTP status code MHD_HTTP_SERVICE_UNAVAILABLE.
   */
  TALER_EC_PAY_EXCHANGE_KEYS_FAILURE = 2120,

  /**
   * The payment is too late, the offer has expired.
   * This response is
   * provided with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_OFFER_EXPIRED = 2121,

  /**
   * The "merchant" field is missing in the proposal data.
   * This response is
   * provided with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_PAY_MERCHANT_FIELD_MISSING = 2122,

  /**
   * Failed computing a hash code (likely server out-of-memory).
   * This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_FAILED_COMPUTE_PROPOSAL_HASH = 2123,

  /**
   * Failed to locate merchant's account information matching the
   * wire hash given in the proposal.
   * This response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_WIRE_HASH_UNKNOWN = 2124,

  /**
   * We got different currencies for the wire fee and the maximum wire
   * fee.  This response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PAY_WIRE_FEE_CURRENCY_MISSMATCH = 2125,


  /**
   * Integer overflow with sepcified timestamp argument detected.
   * This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_HISTORY_TIMESTAMP_OVERFLOW = 2200,

  /**
   * Failed to retrieve history from merchant database.
   * This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_HISTORY_DB_FETCH_ERROR = 2201,

  /**
   * Instance used to retrieve history is unknown to the
   * merchant.
   */
  TALER_EC_HISTORY_INSTANCE_UNKNOWN = 2202,

  /**
   * We failed to contact the exchange for the /track/transaction
   * request.  This response is provided with HTTP status code
   * MHD_HTTP_SERVICE_UNAVAILABLE.
   */
  TALER_EC_TRACK_TRANSACTION_EXCHANGE_TIMEOUT = 2300,

  /**
   * The backend could not find the merchant instance specified
   * in the request.   This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSACTION_INSTANCE_UNKNOWN = 2301,

  /**
   * The backend could not find the transaction specified
   * in the request.   This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSACTION_TRANSACTION_UNKNOWN = 2302,

  /**
   * The backend had a database access error trying to
   * retrieve transaction data from its database.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSACTION_DB_FETCH_TRANSACTION_ERROR = 2303,

  /**
   * The backend had a database access error trying to
   * retrieve payment data from its database.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSACTION_DB_FETCH_PAYMENT_ERROR = 2304,

  /**
   * The backend found no applicable deposits in the database.
   * This is odd, as we know about the transaction, but not
   * about deposits we made for the transaction.  The response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSACTION_DB_NO_DEPOSITS_ERROR = 2305,

  /**
   * We failed to obtain a wire transfer identifier for one
   * of the coins in the transaction.  The response is
   * provided with HTTP status code MHD_HTTP_FAILED_DEPENDENCY if
   * the exchange had a hard error, or MHD_HTTP_ACCEPTED if the
   * exchange signaled that the transfer was in progress.
   */
  TALER_EC_TRACK_TRANSACTION_COIN_TRACE_ERROR = 2306,

  /**
   * We failed to obtain the full wire transfer identifier for the
   * transfer one of the coins was aggregated into.
   * The response is
   * provided with HTTP status code MHD_HTTP_FAILED_DEPENDENCY.
   */
  TALER_EC_TRACK_TRANSACTION_WIRE_TRANSFER_TRACE_ERROR = 2307,

  /**
   * We got conflicting reports from the exhange with
   * respect to which transfers are included in which
   * aggregate.
   * The response is
   * provided with HTTP status code MHD_HTTP_FAILED_DEPENDENCY.
   */
  TALER_EC_TRACK_TRANSACTION_CONFLICTING_REPORTS = 2308,


  /**
   * We failed to contact the exchange for the /track/transfer
   * request.  This response is provided with HTTP status code
   * MHD_HTTP_SERVICE_UNAVAILABLE.
   */
  TALER_EC_TRACK_TRANSFER_EXCHANGE_TIMEOUT = 2400,

  /**
   * The backend could not find the merchant instance specified
   * in the request.   This response is
   * provided with HTTP status code MHD_HTTP_NOT_FOUND.
   */
  TALER_EC_TRACK_TRANSFER_INSTANCE_UNKNOWN = 2401,

  /**
   * We failed to persist coin wire transfer information in
   * our merchant database.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_STORE_COIN_ERROR = 2402,

  /**
   * We internally failed to execute the /track/transfer request.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_REQUEST_ERROR = 2403,

  /**
   * We failed to persist wire transfer information in
   * our merchant database.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_STORE_TRANSFER_ERROR = 2404,

  /**
   * The exchange returned an error from /track/transfer.
   * The response is
   * provided with HTTP status code MHD_HTTP_FAILED_DEPENDENCY.
   */
  TALER_EC_TRACK_TRANSFER_EXCHANGE_ERROR = 2405,

  /**
   * We failed to fetch deposit information from
   * our merchant database.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_FETCH_DEPOSIT_ERROR = 2406,

  /**
   * We encountered an internal logic error.
   * The response is
   * provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TRACK_TRANSFER_DB_INTERNAL_LOGIC_ERROR = 2407,

  /**
   * The exchange gave conflicting information about a coin which has
   * been wire transferred.
   * The response is provided with HTTP status code
   * MHD_HTTP_INTERNAL_SERVER_ERROR (FIXME: bad choice!).
   */
  TALER_EC_TRACK_TRANSFER_CONFLICTING_REPORTS = 2408,

  /**
   * The merchant backend had problems in creating the JSON response.
   */
  TALER_EC_TRACK_TRANSFER_JSON_RESPONSE_ERROR = 2409,

  /**
   * The exchange charged a different wire fee than what it
   * originally advertised, and it is higher.  The response
   * is provied with an HTTP status of
   * MHD_HTTP_INTERNAL_SERVER_ERROR (FIXME: bad choice!).
   */
  TALER_EC_TRACK_TRANSFER_JSON_BAD_WIRE_FEE = 2410,

  /**
   * The hash provided in the request of /map/in does not match
   * the contract sent alongside in the same request.
   */
  TALER_EC_MAP_IN_UNMATCHED_HASH = 2500,

  /**
   * The backend encountered an error while trying to store the
   * h_contract_terms into the database.
   * The response is provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_PROPOSAL_STORE_DB_ERROR = 2501,

  /**
   * The backend encountered an error while trying to retrieve the
   * proposal data from database.  Likely to be an internal error.
   */
  TALER_EC_PROPOSAL_LOOKUP_DB_ERROR = 2502,

  /**
   * The proposal being looked up is not found on this merchant.
   */
  TALER_EC_PROPOSAL_LOOKUP_NOT_FOUND = 2503,

  /**
   * The proposal had no timestamp and the backend failed to obtain the local time.
   * Likely to be an internal error.
   */
  TALER_EC_PROPOSAL_NO_LOCALTIME = 2504,

  /**
   * The order provided to the backend could not be parsed, some
   * required fields were missing or ill-formed.
   * Returned as a bad request.
   */
  TALER_EC_PROPOSAL_ORDER_PARSE_ERROR = 2505,

  /**
   * The client specified an unknown instance for any of the /refund operations
   */
  TALER_EC_REFUND_INSTANCE_UNKNOWN = 2600,

  /**
   * The frontend gave an unknown order id to issue the refund to.
   */
  TALER_EC_REFUND_ORDER_ID_UNKNOWN = 2601,

  /**
   * The amount to be refunded is inconsistent: either is lower than
   * the previous amount being awarded, or it is too big to be paid back.
   * In this second case, the fault stays on the business dept. side.
   */
  TALER_EC_REFUND_INCONSISTENT_AMOUNT = 2602,

  /**
   * The backend encountered an error while trying to retrieve the
   * payment data from database.  Likely to be an internal error.
   */
  TALER_EC_REFUND_LOOKUP_DB_ERROR = 2603,

  /**
   * The backend encountered an error while trying to retrieve the
   * payment data from database.  Likely to be an internal error.
   */
  TALER_EC_REFUND_MERCHANT_DB_COMMIT_ERROR = 2604,

  /**
   * Payments are stored in a single db transaction; this error indicates
   * that one db operation within that transaction failed.  This might involve
   * storing of coins or other related db operations, like starting/committing
   * the db transaction or marking a contract as paid.
   */
   TALER_EC_PAY_DB_STORE_PAYMENTS_ERROR = 2605,

  /**
   * The backend does not know the instance that was supposed to support
   * the tip.  Likely to be a configuration error. Returned with an
   * HTTP status code of "NOT FOUND".
   */
  TALER_EC_TIP_AUTHORIZE_INSTANCE_UNKNOWN = 2700,

  /**
   * The backend knows the instance that was supposed to support the
   * tip, but it was not configured for tipping (i.e. has no exchange
   * associated with it).  Likely to be a configuration
   * error. Returned with an HTTP status code of "NOT FOUND".
   */
  TALER_EC_TIP_AUTHORIZE_INSTANCE_DOES_NOT_TIP = 2701,

  /**
   * The reserve that was used to fund the tips has expired.
   * Returned with an HTTP status code of "not found".
   */
  TALER_EC_TIP_AUTHORIZE_RESERVE_EXPIRED = 2702,

  /**
   * The reserve that was used to fund the tips was not found in the DB.
   * Returned with an HTTP status code of "not found".
   */
  TALER_EC_TIP_AUTHORIZE_RESERVE_UNKNOWN = 2703,

  /**
   * The backend knows the instance that was supposed to support the
   * tip, and it was configured for tipping. However, the funds
   * remaining are insufficient to cover the tip, and the merchant
   * should top up the reserve.
   * Returned with an HTTP status code of "PRECONDITION FAILED".
   */
  TALER_EC_TIP_AUTHORIZE_INSUFFICIENT_FUNDS = 2704,

  /**
   * The backend had trouble accessing the database to persist
   * information about the tip authorization.
   * Returned with an HTTP status code of internal error.
   */
  TALER_EC_TIP_AUTHORIZE_DB_HARD_ERROR = 2705,

  /**
   * The backend had trouble accessing the database to persist
   * information about the tip authorization.
   * The problem might be fixable by repeating the transaction.
   */
  TALER_EC_TIP_AUTHORIZE_DB_SOFT_ERROR = 2706,

  /**
   * The reserve that was used to fund the tips was never enabled.
   * Returned with an HTTP status code of "not found".
   */
  TALER_EC_TIP_AUTHORIZE_RESERVE_NOT_ENABLED = 2707,

  /**
   * The backend had trouble accessing the database to persist
   * information about enabling tips.
   * Returned with an HTTP status code of internal error.
   */
  TALER_EC_TIP_ENABLE_DB_TRANSACTION_ERROR = 2750,

  /**
   * The tip ID is unknown.  This could happen if the tip has
   * expired.  Returned with an HTTP status code of "not found".
   */
  TALER_EC_TIP_PICKUP_TIP_ID_UNKNOWN = 2800,

  /**
   * The amount requested exceeds the remaining tipping balance for this tip ID.
   * Returned with an HTTP status code of "service unavailable".
   */
  TALER_EC_TIP_PICKUP_NO_FUNDS = 2801,

  /**
   * We encountered a DB error, repeating the request may work.
   */
  TALER_EC_TIP_PICKUP_DB_ERROR_SOFT = 2802,

  /**
   * We encountered a DB error, repeating the request will not help.
   * This is an internal server error.
   */
  TALER_EC_TIP_PICKUP_DB_ERROR_HARD = 2803,

  /**
   * The same pickup ID was already used for picking up a different
   * amount. This points to a very strange internal error as the
   * pickup ID is derived from the denomination key which is tied
   * to a particular amount. Hence this should also be an internal
   * server error.
   */
  TALER_EC_TIP_PICKUP_AMOUNT_CHANGED = 2804,

  /**
   * We failed to contact the exchange to obtain the denomination
   * keys.  Returned with a response code "failed dependency" (424).
   */
  TALER_EC_TIP_PICKUP_EXCHANGE_DOWN = 2805,

  /**
   * We contacted the exchange to obtain any denomination
   * keys, but got no valid keys.
   * Returned with a response code "failed dependency" (424).
   */
  TALER_EC_TIP_PICKUP_EXCHANGE_LACKED_KEYS = 2806,

  /**
   * We contacted the exchange to obtain at least one of
   * the denomination keys specified in the request.
   * Returned with a response code "not found" (404).
   */
  TALER_EC_TIP_PICKUP_EXCHANGE_LACKED_KEY = 2807,

  /**
   * We encountered an arithmetic issue totaling up the
   * amount to withdraw. Returned with a response code
   * of "bad request".
   */
  TALER_EC_TIP_PICKUP_EXCHANGE_AMOUNT_OVERFLOW = 2808,

  /**
   * The number of planchets specified exceeded the
   * limit. Returned with a response code
   * of "bad request".
   */
  TALER_EC_TIP_PICKUP_EXCHANGE_TOO_MANY_PLANCHETS = 2809,

  /**
   * The tip id is unknown.  This could happen if the
   * tip id is wrong or the tip authorization expired.
   */
  TALER_EC_TIP_QUERY_TIP_ID_UNKNOWN = 2810,


  /* ********** /test API error codes ************* */

  /**
   * The exchange failed to compute ECDH.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TEST_ECDH_ERROR = 4000,

  /**
   * The EdDSA test signature is invalid.  This response is provided
   * with HTTP status code MHD_HTTP_BAD_REQUEST.
   */
  TALER_EC_TEST_EDDSA_INVALID = 4001,

  /**
   * The exchange failed to compute the EdDSA test signature.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TEST_EDDSA_ERROR = 4002,

  /**
   * The exchange failed to generate an RSA key.  This response is provided
   * with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TEST_RSA_GEN_ERROR = 4003,

  /**
   * The exchange failed to compute the public RSA key.  This response
   * is provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TEST_RSA_PUB_ERROR = 4004,

  /**
   * The exchange failed to compute the RSA signature.  This response
   * is provided with HTTP status code MHD_HTTP_INTERNAL_SERVER_ERROR.
   */
  TALER_EC_TEST_RSA_SIGN_ERROR = 4005,

  /* *************** Taler BANK/FAKEBANK error codes *************** */

  /**
   * The request cannot be served because the client failed to
   * login.  To be returned along HTTP 401 Unauthorized.
   */
  TALER_EC_BANK_REJECT_LOGIN_FAILED = 5312,

  /**
   * The transaction cannot be rejected becasue it does not exist
   * at the bank.  To be returned along HTTP 404 Not Found.
   */
  TALER_EC_BANK_REJECT_TRANSACTION_NOT_FOUND = 5301,

  /**
   * The client does not own the account credited by the transaction
   * which is to be rejected, so it has no rights do reject it.  To be
   * returned along HTTP 403 Forbidden.
   */
  TALER_EC_BANK_REJECT_NO_RIGHTS = 5313,

  /**
   * The POSTed JSON at /reject was invalid.  To be returned along
   * HTTP 400 Bad Request.
   */
  TALER_EC_BANK_REJECT_JSON_INVALID = 5306,

  /**
   * A URL parameter for /history was missing.  To be returned along
   * HTTP 400 Bad Request.
   */
  TALER_EC_BANK_HISTORY_PARAMETER_MISSING = 5208,

  /**
   * A URL parameter for /history was malformed.  To be returned along
   * HTTP 400 Bad Request.
   */
  TALER_EC_BANK_HISTORY_PARAMETER_MALFORMED = 5209,

  /**
   * The client failed to login for /history.  To be returned along
   * HTTP 401 Unauthorized.
   */
  TALER_EC_BANK_HISTORY_LOGIN_FAILED = 5212,

  /**
   * The bank had trouble obtaining a valid HTTP response.  To be returned
   * along status code 0.
   */
  TALER_EC_BANK_HISTORY_HTTP_FAILURE = 5213,

  /**
   * The debit account for /admin/add/incoming is not known to the
   * bank.  To be returned along HTTP 404 Not Found.
   */
  TALER_EC_BANK_ADD_INCOMING_UNKNOWN_ACCOUNT = 5100,

  /**
   * The client specified the same bank account for both the credit
   * and the debit account.  The bank will not accomplish this operation.
   * To be returned along HTTP 403 Forbidden.
   */
  TALER_EC_BANK_ADD_INCOMING_SAME_ACCOUNT = 5102,

  /**
   * The operation would put the client in a debit situation which is
   * forbidden to them.  To return along HTTP 403 Forbidden.
   */
  TALER_EC_BANK_ADD_INCOMING_UNALLOWED_DEBIT = 5103,

  /**
   * The client POSTed an invalid JSON.  To be returned along HTTP
   * 400 Bad Request.
   */
  TALER_EC_BANK_ADD_INCOMING_JSON_INVALID = 5106,

  /**
   * The client failed to login for /admin/add/incoming.  To be returned
   * along HTTP 401 Unauthorized.
   */
  TALER_EC_BANK_ADD_INCOMING_LOGIN_FAILED = 5112,

  /**
   * End of error code range.
   */
  TALER_EC_END = 9999

};


#endif