/*
This file is part of TALER
Copyright (C) 2014, 2015 Taler Systems SA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see
*/
/**
* @file exchange/taler-exchange-httpd_keystate.h
* @brief management of our private signing keys (denomination keys)
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#ifndef TALER_EXCHANGE_HTTPD_KEYSTATE_H
#define TALER_EXCHANGE_HTTPD_KEYSTATE_H
#include
#include
#include "taler-exchange-httpd.h"
#include "taler_error_codes.h"
#include "taler_exchangedb_lib.h"
/**
* Snapshot of the (coin and signing)
* keys (including private keys) of the exchange.
*/
struct TEH_KS_StateHandle;
/**
* Acquire the key state of the exchange. Updates keys if necessary.
* For every call to #TEH_KS_acquire(), a matching call
* to #TEH_KS_release() must be made.
*
* @param now for what timestamp should we acquire the key state
* @param location name of the function in which the lock is acquired
* @return the key state, NULL on error (usually pretty fatal)
*/
struct TEH_KS_StateHandle *
TEH_KS_acquire_ (struct GNUNET_TIME_Absolute now,
const char *location);
/**
* Release key state, free if necessary (if reference count gets to zero).
*
* @param location name of the function in which the lock is acquired
* @param key_state the key state to release
*/
void
TEH_KS_release_ (const char *location,
struct TEH_KS_StateHandle *key_state);
/**
* Acquire the key state of the exchange. Updates keys if necessary.
* For every call to #TEH_KS_acquire(), a matching call
* to #TEH_KS_release() must be made.
*
* @param now current time snapshot; either true, or given by the
* client via the "now" URL parameter of "/keys".
* @return the key state
*/
#define TEH_KS_acquire(now) TEH_KS_acquire_ (now, __FUNCTION__)
/**
* Release key state, free if necessary (if reference count gets to zero).
*
* @param key_state the key state to release
*/
#define TEH_KS_release(key_state) TEH_KS_release_ (__FUNCTION__, key_state)
/**
* Setup initial #internal_key_state and our signal handlers.
*
* @return #GNUNET_OK on success
*/
int
TEH_KS_init (void);
/**
* Finally, release #internal_key_state and our signal handlers.
*/
void
TEH_KS_free (void);
/**
* Denomination key lookups can be for signing of fresh coins
* or to validate signatures on existing coins. As the validity
* periods for a key differ, the caller must specify which
* use is relevant for the current operation.
*/
enum TEH_KS_DenominationKeyUse
{
/**
* The denomination key is to be used for a withdraw or reveal operation.
*/
TEH_KS_DKU_WITHDRAW,
/**
* The denomination key is to be used for a deposit or melt operation.
*/
TEH_KS_DKU_DEPOSIT,
/**
* The denomination key is to be used for a recoup operation, or to
* melt a coin that was deposited (or melted) before the revocation.
*/
TEH_KS_DKU_RECOUP,
/**
* The key is to be used for a refresh + recoup operation,
* i.e. it is an old coin that regained value from a
* recoup on a new coin derived from the old coin.
*/
TEH_KS_DKU_ZOMBIE
};
/**
* Look up the issue for a denom public key. Note that the result
* is only valid while the @a key_state is not released!
*
* @param key_state state to look in
* @param denom_pub_hash hash of denomination public key
* @param use purpose for which the key is being located
* @param[out] ec set to the error code, in case the operation failed
* @param[out] hc set to the HTTP status code to use
* @return the denomination key issue,
* or NULL if denom_pub could not be found (or is not valid at this time for the given @a use)
*/
struct TALER_EXCHANGEDB_DenominationKey *
TEH_KS_denomination_key_lookup_by_hash (
const struct TEH_KS_StateHandle *key_state,
const struct GNUNET_HashCode *denom_pub_hash,
enum TEH_KS_DenominationKeyUse use,
enum TALER_ErrorCode *ec,
unsigned int *hc);
/**
* Read signals from a pipe in a loop, and reload keys from disk if
* SIGUSR1 is received, terminate if SIGTERM/SIGINT is received, and
* restart if SIGHUP is received.
*
* @return #GNUNET_SYSERR on errors,
* #GNUNET_OK to terminate normally
* #GNUNET_NO to restart an update version of the binary
*/
int
TEH_KS_loop (void);
/**
* Sign the message in @a purpose with the exchange's signing
* key.
*
* @param purpose the message to sign
* @param[out] pub set to the current public signing key of the exchange
* @param[out] sig signature over purpose using current signing key
* @return #GNUNET_OK on success, #GNUNET_SYSERR if we lack key material
*/
int
TEH_KS_sign (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
struct TALER_ExchangePublicKeyP *pub,
struct TALER_ExchangeSignatureP *sig);
/**
* Handle a "/keys" request
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param args array of additional options (must be empty for this function)
* @return MHD result code
*/
int
TEH_handler_keys (const struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
const char *const args[]);
#endif