diff options
Diffstat (limited to 'src/lib/exchange_api_batch_withdraw2.c')
| -rw-r--r-- | src/lib/exchange_api_batch_withdraw2.c | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/src/lib/exchange_api_batch_withdraw2.c b/src/lib/exchange_api_batch_withdraw2.c new file mode 100644 index 000000000..ff1496466 --- /dev/null +++ b/src/lib/exchange_api_batch_withdraw2.c @@ -0,0 +1,441 @@ +/* + This file is part of TALER + Copyright (C) 2014-2023 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_batch_withdraw2.c + * @brief Implementation of /reserves/$RESERVE_PUB/batch-withdraw requests without blinding/unblinding + * @author Christian Grothoff + */ +#include "platform.h" +#include <jansson.h> +#include <microhttpd.h> /* just for HTTP status codes */ +#include <gnunet/gnunet_util_lib.h> +#include <gnunet/gnunet_json_lib.h> +#include <gnunet/gnunet_curl_lib.h> +#include "taler_exchange_service.h" +#include "taler_json_lib.h" +#include "exchange_api_handle.h" +#include "taler_signatures.h" +#include "exchange_api_curl_defaults.h" + + +/** + * @brief A batch withdraw handle + */ +struct TALER_EXCHANGE_BatchWithdraw2Handle +{ + + /** + * The url for this request. + */ + char *url; + + /** + * The /keys material from the exchange + */ + const struct TALER_EXCHANGE_Keys *keys; + + /** + * Handle for the request. + */ + struct GNUNET_CURL_Job *job; + + /** + * Function to call with the result. + */ + TALER_EXCHANGE_BatchWithdraw2Callback cb; + + /** + * Closure for @a cb. + */ + void *cb_cls; + + /** + * Context for #TEH_curl_easy_post(). Keeps the data that must + * persist for Curl to make the upload. + */ + struct TALER_CURL_PostContext post_ctx; + + /** + * Total amount requested (value plus withdraw fee). + */ + struct TALER_Amount requested_amount; + + /** + * Public key of the reserve we are withdrawing from. + */ + struct TALER_ReservePublicKeyP reserve_pub; + + /** + * Number of coins expected. + */ + unsigned int num_coins; +}; + + +/** + * We got a 200 OK response for the /reserves/$RESERVE_PUB/batch-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. As we do not have the + * blinding factor, the signature CANNOT be verified. + * + * If everything checks out, we return the unblinded signature + * to the application via the callback. + * + * @param wh operation handle + * @param json reply from the exchange + * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors + */ +static enum GNUNET_GenericReturnValue +reserve_batch_withdraw_ok (struct TALER_EXCHANGE_BatchWithdraw2Handle *wh, + const json_t *json) +{ + struct TALER_BlindedDenominationSignature blind_sigs[GNUNET_NZL ( + wh->num_coins)]; + const json_t *ja = json_object_get (json, + "ev_sigs"); + const json_t *j; + size_t index; + struct TALER_EXCHANGE_BatchWithdraw2Response bwr = { + .hr.reply = json, + .hr.http_status = MHD_HTTP_OK + }; + + if ( (NULL == ja) || + (! json_is_array (ja)) || + (wh->num_coins != json_array_size (ja)) ) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + json_array_foreach (ja, index, j) + { + struct GNUNET_JSON_Specification spec[] = { + TALER_JSON_spec_blinded_denom_sig ("ev_sig", + &blind_sigs[index]), + GNUNET_JSON_spec_end () + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (j, + spec, + NULL, NULL)) + { + GNUNET_break_op (0); + for (size_t i = 0; i<index; i++) + TALER_blinded_denom_sig_free (&blind_sigs[i]); + return GNUNET_SYSERR; + } + } + + /* signature is valid, return it to the application */ + bwr.details.ok.blind_sigs = blind_sigs; + bwr.details.ok.blind_sigs_length = wh->num_coins; + wh->cb (wh->cb_cls, + &bwr); + /* make sure callback isn't called again after return */ + wh->cb = NULL; + for (unsigned int i = 0; i<wh->num_coins; i++) + TALER_blinded_denom_sig_free (&blind_sigs[i]); + + return GNUNET_OK; +} + + +/** + * Function called when we're done processing the + * HTTP /reserves/$RESERVE_PUB/batch-withdraw request. + * + * @param cls the `struct TALER_EXCHANGE_BatchWithdraw2Handle` + * @param response_code HTTP response code, 0 on error + * @param response parsed JSON result, NULL on error + */ +static void +handle_reserve_batch_withdraw_finished (void *cls, + long response_code, + const void *response) +{ + struct TALER_EXCHANGE_BatchWithdraw2Handle *wh = cls; + const json_t *j = response; + struct TALER_EXCHANGE_BatchWithdraw2Response bwr = { + .hr.reply = j, + .hr.http_status = (unsigned int) response_code + }; + + wh->job = NULL; + switch (response_code) + { + case 0: + bwr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE; + break; + case MHD_HTTP_OK: + if (GNUNET_OK != + reserve_batch_withdraw_ok (wh, + j)) + { + GNUNET_break_op (0); + bwr.hr.http_status = 0; + bwr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; + break; + } + GNUNET_assert (NULL == wh->cb); + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + 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 */ + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_FORBIDDEN: + GNUNET_break_op (0); + /* Nothing really to verify, exchange says one of the signatures is + invalid; as we checked them, this should never happen, we + should pass the JSON reply to the application */ + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.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 this reserve. Can happen if we + query before the wire transfer went through. + We should simply pass the JSON reply to the application. */ + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_CONFLICT: + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.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 */ + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.hr.hint = TALER_JSON_get_error_hint (j); + break; + case MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS: + { + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_fixed_auto ( + "h_payto", + &bwr.details.unavailable_for_legal_reasons.h_payto), + GNUNET_JSON_spec_uint64 ("requirement_row", + &bwr.details.unavailable_for_legal_reasons. + kyc_requirement_id), + GNUNET_JSON_spec_end () + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (j, + spec, + NULL, NULL)) + { + GNUNET_break_op (0); + bwr.hr.http_status = 0; + bwr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; + break; + } + } + case MHD_HTTP_INTERNAL_SERVER_ERROR: + /* Server had an internal issue; we should retry, but this API + leaves this to the application */ + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.hr.hint = TALER_JSON_get_error_hint (j); + break; + default: + /* unexpected response code */ + GNUNET_break_op (0); + bwr.hr.ec = TALER_JSON_get_error_code (j); + bwr.hr.hint = TALER_JSON_get_error_hint (j); + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Unexpected response code %u/%d for exchange batch withdraw\n", + (unsigned int) response_code, + (int) bwr.hr.ec); + break; + } + if (NULL != wh->cb) + { + wh->cb (wh->cb_cls, + &bwr); + wh->cb = NULL; + } + TALER_EXCHANGE_batch_withdraw2_cancel (wh); +} + + +struct TALER_EXCHANGE_BatchWithdraw2Handle * +TALER_EXCHANGE_batch_withdraw2 ( + struct GNUNET_CURL_Context *curl_ctx, + const char *exchange_url, + const struct TALER_EXCHANGE_Keys *keys, + const struct TALER_ReservePrivateKeyP *reserve_priv, + unsigned int pds_length, + const struct TALER_PlanchetDetail pds[static pds_length], + TALER_EXCHANGE_BatchWithdraw2Callback res_cb, + void *res_cb_cls) +{ + struct TALER_EXCHANGE_BatchWithdraw2Handle *wh; + const struct TALER_EXCHANGE_DenomPublicKey *dk; + struct TALER_ReserveSignatureP reserve_sig; + char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 32]; + struct TALER_BlindedCoinHashP bch; + json_t *jc; + + GNUNET_assert (NULL != keys); + wh = GNUNET_new (struct TALER_EXCHANGE_BatchWithdraw2Handle); + wh->keys = keys; + wh->cb = res_cb; + wh->cb_cls = res_cb_cls; + wh->num_coins = pds_length; + GNUNET_assert (GNUNET_OK == + TALER_amount_set_zero (keys->currency, + &wh->requested_amount)); + GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv, + &wh->reserve_pub.eddsa_pub); + { + char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2]; + char *end; + + end = GNUNET_STRINGS_data_to_string ( + &wh->reserve_pub, + sizeof (struct TALER_ReservePublicKeyP), + pub_str, + sizeof (pub_str)); + *end = '\0'; + GNUNET_snprintf (arg_str, + sizeof (arg_str), + "reserves/%s/batch-withdraw", + pub_str); + } + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Attempting to batch-withdraw from reserve %s\n", + TALER_B2S (&wh->reserve_pub)); + wh->url = TALER_url_join (exchange_url, + arg_str, + NULL); + if (NULL == wh->url) + { + GNUNET_break (0); + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + return NULL; + } + jc = json_array (); + GNUNET_assert (NULL != jc); + for (unsigned int i = 0; i<pds_length; i++) + { + const struct TALER_PlanchetDetail *pd = &pds[i]; + struct TALER_Amount coin_total; + json_t *withdraw_obj; + + dk = TALER_EXCHANGE_get_denomination_key_by_hash (keys, + &pd->denom_pub_hash); + if (NULL == dk) + { + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + json_decref (jc); + GNUNET_break (0); + return NULL; + } + /* Compute how much we expected to charge to the reserve */ + if (0 > + TALER_amount_add (&coin_total, + &dk->fees.withdraw, + &dk->value)) + { + /* Overflow here? Very strange, our CPU must be fried... */ + GNUNET_break (0); + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + json_decref (jc); + return NULL; + } + if (0 > + TALER_amount_add (&wh->requested_amount, + &wh->requested_amount, + &coin_total)) + { + /* Overflow here? Very strange, our CPU must be fried... */ + GNUNET_break (0); + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + json_decref (jc); + return NULL; + } + TALER_coin_ev_hash (&pd->blinded_planchet, + &pd->denom_pub_hash, + &bch); + TALER_wallet_withdraw_sign (&pd->denom_pub_hash, + &coin_total, + &bch, + reserve_priv, + &reserve_sig); + withdraw_obj = GNUNET_JSON_PACK ( + GNUNET_JSON_pack_data_auto ("denom_pub_hash", + &pd->denom_pub_hash), + TALER_JSON_pack_blinded_planchet ("coin_ev", + &pd->blinded_planchet), + GNUNET_JSON_pack_data_auto ("reserve_sig", + &reserve_sig)); + GNUNET_assert (NULL != withdraw_obj); + GNUNET_assert (0 == + json_array_append_new (jc, + withdraw_obj)); + } + { + CURL *eh; + json_t *req; + + req = GNUNET_JSON_PACK ( + GNUNET_JSON_pack_array_steal ("planchets", + jc)); + eh = TALER_EXCHANGE_curl_easy_get_ (wh->url); + if ( (NULL == eh) || + (GNUNET_OK != + TALER_curl_easy_post (&wh->post_ctx, + eh, + req)) ) + { + GNUNET_break (0); + if (NULL != eh) + curl_easy_cleanup (eh); + json_decref (req); + TALER_EXCHANGE_batch_withdraw2_cancel (wh); + return NULL; + } + json_decref (req); + wh->job = GNUNET_CURL_job_add2 (curl_ctx, + eh, + wh->post_ctx.headers, + &handle_reserve_batch_withdraw_finished, + wh); + } + return wh; +} + + +void +TALER_EXCHANGE_batch_withdraw2_cancel ( + struct TALER_EXCHANGE_BatchWithdraw2Handle *wh) +{ + if (NULL != wh->job) + { + GNUNET_CURL_job_cancel (wh->job); + wh->job = NULL; + } + GNUNET_free (wh->url); + TALER_curl_easy_post_finished (&wh->post_ctx); + GNUNET_free (wh); +} |