diff options
Diffstat (limited to 'src/exchange/taler-exchange-httpd_refresh_link.c')
| -rw-r--r-- | src/exchange/taler-exchange-httpd_refresh_link.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/src/exchange/taler-exchange-httpd_refresh_link.c b/src/exchange/taler-exchange-httpd_refresh_link.c new file mode 100644 index 000000000..c85431f04 --- /dev/null +++ b/src/exchange/taler-exchange-httpd_refresh_link.c @@ -0,0 +1,286 @@ +/* + This file is part of TALER + Copyright (C) 2014-2017 Inria & GNUnet e.V. + + 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 <http://www.gnu.org/licenses/> +*/ +/** + * @file taler-exchange-httpd_refresh_link.c + * @brief Handle /refresh/link requests + * @author Florian Dold + * @author Benedikt Mueller + * @author Christian Grothoff + */ +#include "platform.h" +#include <gnunet/gnunet_util_lib.h> +#include <jansson.h> +#include <microhttpd.h> +#include "taler-exchange-httpd_parsing.h" +#include "taler-exchange-httpd_mhd.h" +#include "taler-exchange-httpd_refresh_link.h" +#include "taler-exchange-httpd_responses.h" +#include "taler-exchange-httpd_keystate.h" + + +/** + * @brief Information for each session a coin was melted into. + */ +struct TEH_RESPONSE_LinkSessionInfo +{ + /** + * Transfer public key of the coin. + */ + struct TALER_TransferPublicKeyP transfer_pub; + + /** + * Linked data of coins being created in the session. + */ + struct TALER_EXCHANGEDB_LinkDataList *ldl; + +}; + + +/** + * Closure for #handle_transfer_data(). + */ +struct HTD_Context +{ + + /** + * Session link data we collect. + */ + struct TEH_RESPONSE_LinkSessionInfo *sessions; + + /** + * Database session. Nothing to do with @a sessions. + */ + struct TALER_EXCHANGEDB_Session *session; + + /** + * MHD connection, for queueing replies. + */ + struct MHD_Connection *connection; + + /** + * Number of sessions the coin was melted into. + */ + unsigned int num_sessions; + + /** + * How are we expected to proceed. #GNUNET_SYSERR if we + * failed to return an error (should return #MHD_NO). + * #GNUNET_NO if we succeeded in queueing an MHD error + * (should return #MHD_YES from #TEH_execute_refresh_link), + * #GNUNET_OK if we should call #reply_refresh_link_success(). + */ + int status; +}; + + +/** + * Send a response for "/refresh/link". + * + * @param connection the connection to send the response to + * @param num_sessions number of sessions the coin was used in + * @param sessions array of @a num_session entries with + * information for each session + * @return a MHD result code + */ +static int +reply_refresh_link_success (struct MHD_Connection *connection, + unsigned int num_sessions, + const struct TEH_RESPONSE_LinkSessionInfo *sessions) +{ + json_t *root; + json_t *mlist; + int res; + unsigned int i; + + mlist = json_array (); + for (i=0;i<num_sessions;i++) + { + const struct TALER_EXCHANGEDB_LinkDataList *pos; + json_t *list = json_array (); + + for (pos = sessions[i].ldl; NULL != pos; pos = pos->next) + { + json_t *obj; + + obj = json_object (); + json_object_set_new (obj, + "denom_pub", + GNUNET_JSON_from_rsa_public_key (pos->denom_pub.rsa_public_key)); + json_object_set_new (obj, + "ev_sig", + GNUNET_JSON_from_rsa_signature (pos->ev_sig.rsa_signature)); + GNUNET_assert (0 == + json_array_append_new (list, + obj)); + } + root = json_object (); + json_object_set_new (root, + "new_coins", + list); + json_object_set_new (root, + "transfer_pub", + GNUNET_JSON_from_data_auto (&sessions[i].transfer_pub)); + GNUNET_assert (0 == + json_array_append_new (mlist, + root)); + } + res = TEH_RESPONSE_reply_json (connection, + mlist, + MHD_HTTP_OK); + json_decref (mlist); + return res; +} + + +/** + * Function called with the session hashes and transfer secret + * information for a given coin. Gets the linkage data and + * builds the reply for the client. + * + * + * @param cls closure, a `struct HTD_Context` + * @param session_hash a session the coin was melted in + * @param transfer_pub public transfer key for the session + */ +static void +handle_transfer_data (void *cls, + const struct GNUNET_HashCode *session_hash, + const struct TALER_TransferPublicKeyP *transfer_pub) +{ + struct HTD_Context *ctx = cls; + struct TALER_EXCHANGEDB_LinkDataList *ldl; + struct TEH_RESPONSE_LinkSessionInfo *lsi; + + if (GNUNET_OK != ctx->status) + return; + ldl = TEH_plugin->get_link_data_list (TEH_plugin->cls, + ctx->session, + session_hash); + if (NULL == ldl) + { + ctx->status = GNUNET_NO; + if (MHD_NO == + TEH_RESPONSE_reply_json_pack (ctx->connection, + MHD_HTTP_NOT_FOUND, + "{s:s}", + "error", + "link data not found (link)")) + ctx->status = GNUNET_SYSERR; + return; + } + GNUNET_array_grow (ctx->sessions, + ctx->num_sessions, + ctx->num_sessions + 1); + lsi = &ctx->sessions[ctx->num_sessions - 1]; + lsi->transfer_pub = *transfer_pub; + lsi->ldl = ldl; +} + + +/** + * Execute a "/refresh/link". Returns the linkage information that + * will allow the owner of a coin to follow the refresh trail to + * the refreshed coin. + * + * @param connection the MHD connection to handle + * @param coin_pub public key of the coin to link + * @return MHD result code + */ +static int +execute_refresh_link (struct MHD_Connection *connection, + const struct TALER_CoinSpendPublicKeyP *coin_pub) +{ + struct HTD_Context ctx; + int res; + unsigned int i; + + if (NULL == (ctx.session = TEH_plugin->get_session (TEH_plugin->cls))) + { + GNUNET_break (0); + return TEH_RESPONSE_reply_internal_db_error (connection, + TALER_EC_DB_SETUP_FAILED); + } + ctx.connection = connection; + ctx.num_sessions = 0; + ctx.sessions = NULL; + ctx.status = GNUNET_OK; + res = TEH_plugin->get_transfer (TEH_plugin->cls, + ctx.session, + coin_pub, + &handle_transfer_data, + &ctx); + if (GNUNET_SYSERR == ctx.status) + { + res = MHD_NO; + goto cleanup; + } + if (GNUNET_NO == ctx.status) + { + res = MHD_YES; + goto cleanup; + } + GNUNET_assert (GNUNET_OK == ctx.status); + if (0 == ctx.num_sessions) + return TEH_RESPONSE_reply_arg_unknown (connection, + TALER_EC_REFRESH_LINK_COIN_UNKNOWN, + "coin_pub"); + res = reply_refresh_link_success (connection, + ctx.num_sessions, + ctx.sessions); + cleanup: + for (i=0;i<ctx.num_sessions;i++) + TEH_plugin->free_link_data_list (TEH_plugin->cls, + ctx.sessions[i].ldl); + GNUNET_free_non_null (ctx.sessions); + return res; +} + + +/** + * Handle a "/refresh/link" request. Note that for "/refresh/link" + * we do use a simple HTTP GET, and a HTTP POST! + * + * @param rh context of the handler + * @param connection the MHD connection to handle + * @param[in,out] connection_cls the connection's closure (can be updated) + * @param upload_data upload data + * @param[in,out] upload_data_size number of bytes (left) in @a upload_data + * @return MHD result code + */ +int +TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh, + struct MHD_Connection *connection, + void **connection_cls, + const char *upload_data, + size_t *upload_data_size) +{ + struct TALER_CoinSpendPublicKeyP coin_pub; + int res; + + res = TEH_PARSE_mhd_request_arg_data (connection, + "coin_pub", + &coin_pub, + sizeof (struct TALER_CoinSpendPublicKeyP)); + if (GNUNET_SYSERR == res) + return MHD_NO; + if (GNUNET_OK != res) + return MHD_YES; + return execute_refresh_link (connection, + &coin_pub); +} + + +/* end of taler-exchange-httpd_refresh_link.c */ |