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author | Özgür Kesim <oec-taler@kesim.org> | 2022-02-18 00:44:55 +0100 |
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committer | Özgür Kesim <oec-taler@kesim.org> | 2022-02-18 00:50:31 +0100 |
commit | f4f502d037a84a38db4bc21a1db06324a05d26aa (patch) | |
tree | abd1d813c9e1a9303d60edd3600a9e39f9d3d91a /src/lib/exchange_api_csr_withdraw.c | |
parent | a78b3345fbf017b1cddfd09afb4b2c29287b0bba (diff) | |
parent | 22fe5da700df7328de183470c1c7f59b21c9f4f9 (diff) | |
download | exchange-f4f502d037a84a38db4bc21a1db06324a05d26aa.tar.xz |
-minor merge conflict resolves
Diffstat (limited to 'src/lib/exchange_api_csr_withdraw.c')
-rw-r--r-- | src/lib/exchange_api_csr_withdraw.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/src/lib/exchange_api_csr_withdraw.c b/src/lib/exchange_api_csr_withdraw.c new file mode 100644 index 000000000..d23f8ef85 --- /dev/null +++ b/src/lib/exchange_api_csr_withdraw.c @@ -0,0 +1,284 @@ +/* + This file is part of TALER + Copyright (C) 2014-2022 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 lib/exchange_api_csr_withdraw.c + * @brief Implementation of /csr-withdraw requests (get R in exchange used for Clause Schnorr withdraw and refresh) + * @author Lucien Heuzeveldt + * @author Gian Demarmels + */ +#include "platform.h" +#include <jansson.h> +#include <microhttpd.h> /* just for HTTP status codes */ +#include <gnunet/gnunet_util_lib.h> +#include <gnunet/gnunet_json_lib.h> +#include <gnunet/gnunet_curl_lib.h> +#include "taler_exchange_service.h" +#include "taler_json_lib.h" +#include "exchange_api_handle.h" +#include "taler_signatures.h" +#include "exchange_api_curl_defaults.h" + + +/** + * @brief A Clause Schnorr R Handle + */ +struct TALER_EXCHANGE_CsRWithdrawHandle +{ + /** + * The connection to exchange this request handle will use + */ + struct TALER_EXCHANGE_Handle *exchange; + + /** + * Function to call with the result. + */ + TALER_EXCHANGE_CsRWithdrawCallback cb; + + /** + * Closure for @a cb. + */ + void *cb_cls; + + /** + * The url for this request. + */ + char *url; + + /** + * Handle for the request. + */ + struct GNUNET_CURL_Job *job; + + /** + * Context for #TEH_curl_easy_post(). Keeps the data that must + * persist for Curl to make the upload. + */ + struct TALER_CURL_PostContext post_ctx; +}; + + +/** + * We got a 200 OK response for the /reserves/$RESERVE_PUB/withdraw operation. + * Extract the coin's signature and return it to the caller. The signature we + * get from the exchange is for the blinded value. Thus, we first must + * unblind it and then should verify its validity against our coin's hash. + * + * If everything checks out, we return the unblinded signature + * to the application via the callback. + * + * @param csrh operation handle + * @param av reply from the exchange + * @param hr http response details + * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors + */ +static enum GNUNET_GenericReturnValue +csr_ok (struct TALER_EXCHANGE_CsRWithdrawHandle *csrh, + const json_t *av, + struct TALER_EXCHANGE_HttpResponse *hr) +{ + struct TALER_EXCHANGE_CsRWithdrawResponse csrr = { + .hr = *hr, + }; + struct GNUNET_JSON_Specification spec[] = { + TALER_JSON_spec_exchange_withdraw_values ( + "ewv", + &csrr.details.success.alg_values), + GNUNET_JSON_spec_end () + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (av, + spec, + NULL, NULL)) + { + GNUNET_break_op (0); + return GNUNET_SYSERR; + } + csrh->cb (csrh->cb_cls, + &csrr); + return GNUNET_OK; +} + + +/** + * Function called when we're done processing the HTTP /csr request. + * + * @param cls the `struct TALER_EXCHANGE_CsRWithdrawHandle` + * @param response_code HTTP response code, 0 on error + * @param response parsed JSON result, NULL on error + */ +static void +handle_csr_finished (void *cls, + long response_code, + const void *response) +{ + struct TALER_EXCHANGE_CsRWithdrawHandle *csrh = cls; + const json_t *j = response; + struct TALER_EXCHANGE_HttpResponse hr = { + .reply = j, + .http_status = (unsigned int) response_code + }; + struct TALER_EXCHANGE_CsRWithdrawResponse csrr = { + .hr = hr + }; + + csrh->job = NULL; + switch (response_code) + { + case 0: + csrr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE; + break; + case MHD_HTTP_OK: + { + if (GNUNET_OK != + csr_ok (csrh, + response, + &hr)) + { + GNUNET_break_op (0); + csrr.hr.http_status = 0; + csrr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; + break; + } + } + TALER_EXCHANGE_csr_withdraw_cancel (csrh); + return; + case MHD_HTTP_BAD_REQUEST: + /* This should never happen, either us or the exchange is buggy + (or API version conflict); just pass JSON reply to the application */ + csrr.hr.ec = TALER_JSON_get_error_code (j); + csrr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_NOT_FOUND: + /* Nothing really to verify, the exchange basically just says + that it doesn't know the /csr endpoint or denomination. + Can happen if the exchange doesn't support Clause Schnorr. + We should simply pass the JSON reply to the application. */ + csrr.hr.ec = TALER_JSON_get_error_code (j); + csrr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_GONE: + /* could happen if denomination was revoked */ + /* Note: one might want to check /keys for revocation + signature here, alas tricky in case our /keys + is outdated => left to clients */ + csrr.hr.ec = TALER_JSON_get_error_code (j); + csrr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_INTERNAL_SERVER_ERROR: + /* Server had an internal issue; we should retry, but this API + leaves this to the application */ + csrr.hr.ec = TALER_JSON_get_error_code (j); + csrr.hr.hint = TALER_JSON_get_error_hint (j); + break; + default: + /* unexpected response code */ + GNUNET_break_op (0); + csrr.hr.ec = TALER_JSON_get_error_code (j); + csrr.hr.hint = TALER_JSON_get_error_hint (j); + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Unexpected response code %u/%d for CS R request\n", + (unsigned int) response_code, + (int) hr.ec); + break; + } + csrh->cb (csrh->cb_cls, + &csrr); + csrh->cb = NULL; + TALER_EXCHANGE_csr_withdraw_cancel (csrh); +} + + +struct TALER_EXCHANGE_CsRWithdrawHandle * +TALER_EXCHANGE_csr_withdraw (struct TALER_EXCHANGE_Handle *exchange, + const struct TALER_EXCHANGE_DenomPublicKey *pk, + const struct TALER_CsNonce *nonce, + TALER_EXCHANGE_CsRWithdrawCallback res_cb, + void *res_cb_cls) +{ + struct TALER_EXCHANGE_CsRWithdrawHandle *csrh; + + if (TALER_DENOMINATION_CS != pk->key.cipher) + { + GNUNET_break (0); + return NULL; + } + csrh = GNUNET_new (struct TALER_EXCHANGE_CsRWithdrawHandle); + csrh->exchange = exchange; + csrh->cb = res_cb; + csrh->cb_cls = res_cb_cls; + csrh->url = TEAH_path_to_url (exchange, + "/csr-withdraw"); + if (NULL == csrh->url) + { + GNUNET_free (csrh); + return NULL; + } + + { + CURL *eh; + struct GNUNET_CURL_Context *ctx; + json_t *req; + + req = GNUNET_JSON_PACK ( + GNUNET_JSON_pack_data_varsize ("nonce", + nonce, + sizeof(struct TALER_CsNonce)), + GNUNET_JSON_pack_data_varsize ("denom_pub_hash", + &pk->h_key, + sizeof(struct TALER_DenominationHash))); + GNUNET_assert (NULL != req); + ctx = TEAH_handle_to_context (exchange); + eh = TALER_EXCHANGE_curl_easy_get_ (csrh->url); + if ( (NULL == eh) || + (GNUNET_OK != + TALER_curl_easy_post (&csrh->post_ctx, + eh, + req)) ) + { + GNUNET_break (0); + if (NULL != eh) + curl_easy_cleanup (eh); + json_decref (req); + GNUNET_free (csrh->url); + GNUNET_free (csrh); + return NULL; + } + json_decref (req); + csrh->job = GNUNET_CURL_job_add2 (ctx, + eh, + csrh->post_ctx.headers, + &handle_csr_finished, + csrh); + } + return csrh; +} + + +void +TALER_EXCHANGE_csr_withdraw_cancel (struct + TALER_EXCHANGE_CsRWithdrawHandle *csrh) +{ + if (NULL != csrh->job) + { + GNUNET_CURL_job_cancel (csrh->job); + csrh->job = NULL; + } + GNUNET_free (csrh->url); + TALER_curl_easy_post_finished (&csrh->post_ctx); + GNUNET_free (csrh); +} |