exchange_api_post-purses-PURSE_PUB-merge.c (14499B)
1 /* 2 This file is part of TALER 3 Copyright (C) 2022-2023 Taler Systems SA 4 5 TALER is free software; you can redistribute it and/or modify it under the 6 terms of the GNU General Public License as published by the Free Software 7 Foundation; either version 3, or (at your option) any later version. 8 9 TALER is distributed in the hope that it will be useful, but WITHOUT ANY 10 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR 11 A PARTICULAR PURPOSE. See the GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License along with 14 TALER; see the file COPYING. If not, see 15 <http://www.gnu.org/licenses/> 16 */ 17 /** 18 * @file lib/exchange_api_post-purses-PURSE_PUB-merge.c 19 * @brief Implementation of the client to merge a purse 20 * into an account 21 * @author Christian Grothoff 22 */ 23 #include "taler/platform.h" 24 #include <jansson.h> 25 #include <microhttpd.h> /* just for HTTP status codes */ 26 #include <gnunet/gnunet_util_lib.h> 27 #include <gnunet/gnunet_json_lib.h> 28 #include <gnunet/gnunet_curl_lib.h> 29 #include "taler/taler_json_lib.h" 30 #include "taler/taler_exchange_service.h" 31 #include "exchange_api_handle.h" 32 #include "exchange_api_common.h" 33 #include "taler/taler_signatures.h" 34 #include "exchange_api_curl_defaults.h" 35 36 37 /** 38 * @brief A purse merge with deposit handle 39 */ 40 struct TALER_EXCHANGE_PostPursesMergeHandle 41 { 42 43 /** 44 * The curl context for this request. 45 */ 46 struct GNUNET_CURL_Context *ctx; 47 48 /** 49 * The base URL of the exchange. 50 */ 51 char *base_url; 52 53 /** 54 * The keys of the exchange this request handle will use 55 */ 56 struct TALER_EXCHANGE_Keys *keys; 57 58 /** 59 * The url for this request, set during _start. 60 */ 61 char *url; 62 63 /** 64 * Context for #TEH_curl_easy_post(). Keeps the data that must 65 * persist for Curl to make the upload. 66 */ 67 struct TALER_CURL_PostContext post_ctx; 68 69 /** 70 * Handle for the request. 71 */ 72 struct GNUNET_CURL_Job *job; 73 74 /** 75 * Function to call with the result. 76 */ 77 TALER_EXCHANGE_PostPursesMergeCallback cb; 78 79 /** 80 * Closure for @a cb. 81 */ 82 TALER_EXCHANGE_POST_PURSES_MERGE_RESULT_CLOSURE *cb_cls; 83 84 /** 85 * Base URL of the provider hosting the @e reserve_pub. 86 */ 87 char *provider_url; 88 89 /** 90 * Signature for our operation. 91 */ 92 struct TALER_PurseMergeSignatureP merge_sig; 93 94 /** 95 * Expected value in the purse after fees. 96 */ 97 struct TALER_Amount purse_value_after_fees; 98 99 /** 100 * Public key of the reserve public key. 101 */ 102 struct TALER_ReservePublicKeyP reserve_pub; 103 104 /** 105 * Public key of the purse. 106 */ 107 struct TALER_PurseContractPublicKeyP purse_pub; 108 109 /** 110 * Hash over the purse's contract terms. 111 */ 112 struct TALER_PrivateContractHashP h_contract_terms; 113 114 /** 115 * When does the purse expire. 116 */ 117 struct GNUNET_TIME_Timestamp purse_expiration; 118 119 /** 120 * Time of the merge. 121 */ 122 struct GNUNET_TIME_Timestamp merge_timestamp; 123 124 /** 125 * Our merge key. 126 */ 127 struct TALER_PurseMergePrivateKeyP merge_priv; 128 129 /** 130 * Reserve signature affirming the merge. 131 */ 132 struct TALER_ReserveSignatureP reserve_sig; 133 134 /** 135 * The JSON body to post, built during _create and posted during _start. 136 */ 137 json_t *body; 138 139 }; 140 141 142 /** 143 * Function called when we're done processing the 144 * HTTP /purse/$PID/merge request. 145 * 146 * @param cls the `struct TALER_EXCHANGE_PostPursesMergeHandle` 147 * @param response_code HTTP response code, 0 on error 148 * @param response parsed JSON result, NULL on error 149 */ 150 static void 151 handle_purse_merge_finished (void *cls, 152 long response_code, 153 const void *response) 154 { 155 struct TALER_EXCHANGE_PostPursesMergeHandle *pch = cls; 156 const json_t *j = response; 157 struct TALER_EXCHANGE_PostPursesMergeResponse dr = { 158 .hr.reply = j, 159 .hr.http_status = (unsigned int) response_code, 160 .reserve_sig = &pch->reserve_sig 161 }; 162 163 pch->job = NULL; 164 switch (response_code) 165 { 166 case 0: 167 dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE; 168 break; 169 case MHD_HTTP_OK: 170 { 171 struct GNUNET_JSON_Specification spec[] = { 172 GNUNET_JSON_spec_fixed_auto ("exchange_sig", 173 &dr.details.ok.exchange_sig), 174 GNUNET_JSON_spec_fixed_auto ("exchange_pub", 175 &dr.details.ok.exchange_pub), 176 GNUNET_JSON_spec_timestamp ("exchange_timestamp", 177 &dr.details.ok.etime), 178 TALER_JSON_spec_amount ("merge_amount", 179 pch->purse_value_after_fees.currency, 180 &dr.details.ok.merge_amount), 181 GNUNET_JSON_spec_end () 182 }; 183 184 if (GNUNET_OK != 185 GNUNET_JSON_parse (j, 186 spec, 187 NULL, NULL)) 188 { 189 GNUNET_break_op (0); 190 dr.hr.http_status = 0; 191 dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; 192 break; 193 } 194 if (GNUNET_OK != 195 TALER_EXCHANGE_test_signing_key (pch->keys, 196 &dr.details.ok.exchange_pub)) 197 { 198 GNUNET_break_op (0); 199 dr.hr.http_status = 0; 200 dr.hr.ec = TALER_EC_EXCHANGE_PURSE_MERGE_EXCHANGE_SIGNATURE_INVALID; 201 break; 202 } 203 if (GNUNET_OK != 204 TALER_exchange_online_purse_merged_verify ( 205 dr.details.ok.etime, 206 pch->purse_expiration, 207 &pch->purse_value_after_fees, 208 &pch->purse_pub, 209 &pch->h_contract_terms, 210 &pch->reserve_pub, 211 pch->provider_url, 212 &dr.details.ok.exchange_pub, 213 &dr.details.ok.exchange_sig)) 214 { 215 GNUNET_break_op (0); 216 dr.hr.http_status = 0; 217 dr.hr.ec = TALER_EC_EXCHANGE_PURSE_MERGE_EXCHANGE_SIGNATURE_INVALID; 218 break; 219 } 220 } 221 break; 222 case MHD_HTTP_BAD_REQUEST: 223 /* This should never happen, either us or the exchange is buggy 224 (or API version conflict); just pass JSON reply to the application */ 225 dr.hr.ec = TALER_JSON_get_error_code (j); 226 dr.hr.hint = TALER_JSON_get_error_hint (j); 227 break; 228 case MHD_HTTP_PAYMENT_REQUIRED: 229 /* purse was not (yet) full */ 230 dr.hr.ec = TALER_JSON_get_error_code (j); 231 dr.hr.hint = TALER_JSON_get_error_hint (j); 232 break; 233 case MHD_HTTP_FORBIDDEN: 234 dr.hr.ec = TALER_JSON_get_error_code (j); 235 dr.hr.hint = TALER_JSON_get_error_hint (j); 236 /* Nothing really to verify, exchange says one of the signatures is 237 invalid; as we checked them, this should never happen, we 238 should pass the JSON reply to the application */ 239 break; 240 case MHD_HTTP_NOT_FOUND: 241 dr.hr.ec = TALER_JSON_get_error_code (j); 242 dr.hr.hint = TALER_JSON_get_error_hint (j); 243 /* Nothing really to verify, this should never 244 happen, we should pass the JSON reply to the application */ 245 break; 246 case MHD_HTTP_CONFLICT: 247 { 248 struct TALER_PurseMergePublicKeyP merge_pub; 249 250 GNUNET_CRYPTO_eddsa_key_get_public (&pch->merge_priv.eddsa_priv, 251 &merge_pub.eddsa_pub); 252 if (GNUNET_OK != 253 TALER_EXCHANGE_check_purse_merge_conflict_ ( 254 &pch->merge_sig, 255 &merge_pub, 256 &pch->purse_pub, 257 pch->provider_url, 258 j)) 259 { 260 GNUNET_break_op (0); 261 dr.hr.http_status = 0; 262 dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; 263 break; 264 } 265 break; 266 } 267 break; 268 case MHD_HTTP_GONE: 269 /* could happen if denomination was revoked */ 270 /* Note: one might want to check /keys for revocation 271 signature here, alas tricky in case our /keys 272 is outdated => left to clients */ 273 dr.hr.ec = TALER_JSON_get_error_code (j); 274 dr.hr.hint = TALER_JSON_get_error_hint (j); 275 break; 276 case MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS: 277 dr.hr.ec = TALER_JSON_get_error_code (j); 278 dr.hr.hint = TALER_JSON_get_error_hint (j); 279 if (GNUNET_OK != 280 TALER_EXCHANGE_parse_451 (&dr.details.unavailable_for_legal_reasons, 281 j)) 282 { 283 GNUNET_break_op (0); 284 dr.hr.http_status = 0; 285 dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; 286 break; 287 } 288 break; 289 case MHD_HTTP_INTERNAL_SERVER_ERROR: 290 dr.hr.ec = TALER_JSON_get_error_code (j); 291 dr.hr.hint = TALER_JSON_get_error_hint (j); 292 /* Server had an internal issue; we should retry, but this API 293 leaves this to the application */ 294 break; 295 default: 296 /* unexpected response code */ 297 dr.hr.ec = TALER_JSON_get_error_code (j); 298 dr.hr.hint = TALER_JSON_get_error_hint (j); 299 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, 300 "Unexpected response code %u/%d for exchange deposit\n", 301 (unsigned int) response_code, 302 dr.hr.ec); 303 GNUNET_break_op (0); 304 break; 305 } 306 if (NULL != pch->cb) 307 { 308 pch->cb (pch->cb_cls, 309 &dr); 310 pch->cb = NULL; 311 } 312 TALER_EXCHANGE_post_purses_merge_cancel (pch); 313 } 314 315 316 struct TALER_EXCHANGE_PostPursesMergeHandle * 317 TALER_EXCHANGE_post_purses_merge_create ( 318 struct GNUNET_CURL_Context *ctx, 319 const char *url, 320 struct TALER_EXCHANGE_Keys *keys, 321 const char *reserve_exchange_url, 322 const struct TALER_ReservePrivateKeyP *reserve_priv, 323 const struct TALER_PurseContractPublicKeyP *purse_pub, 324 const struct TALER_PurseMergePrivateKeyP *merge_priv, 325 const struct TALER_PrivateContractHashP *h_contract_terms, 326 uint8_t min_age, 327 const struct TALER_Amount *purse_value_after_fees, 328 struct GNUNET_TIME_Timestamp purse_expiration, 329 struct GNUNET_TIME_Timestamp merge_timestamp) 330 { 331 struct TALER_EXCHANGE_PostPursesMergeHandle *pch; 332 333 pch = GNUNET_new (struct TALER_EXCHANGE_PostPursesMergeHandle); 334 pch->ctx = ctx; 335 pch->base_url = GNUNET_strdup (url); 336 pch->merge_priv = *merge_priv; 337 pch->purse_pub = *purse_pub; 338 pch->h_contract_terms = *h_contract_terms; 339 pch->purse_expiration = purse_expiration; 340 pch->purse_value_after_fees = *purse_value_after_fees; 341 pch->merge_timestamp = merge_timestamp; 342 if (NULL == reserve_exchange_url) 343 pch->provider_url = GNUNET_strdup (url); 344 else 345 pch->provider_url = GNUNET_strdup (reserve_exchange_url); 346 GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv, 347 &pch->reserve_pub.eddsa_pub); 348 349 { 350 struct TALER_Amount zero_purse_fee; 351 352 GNUNET_assert (GNUNET_OK == 353 TALER_amount_set_zero (purse_value_after_fees->currency, 354 &zero_purse_fee)); 355 TALER_wallet_account_merge_sign (pch->merge_timestamp, 356 &pch->purse_pub, 357 purse_expiration, 358 h_contract_terms, 359 purse_value_after_fees, 360 &zero_purse_fee, 361 min_age, 362 TALER_WAMF_MODE_MERGE_FULLY_PAID_PURSE, 363 reserve_priv, 364 &pch->reserve_sig); 365 } 366 pch->keys = TALER_EXCHANGE_keys_incref (keys); 367 return pch; 368 } 369 370 371 enum TALER_ErrorCode 372 TALER_EXCHANGE_post_purses_merge_start ( 373 struct TALER_EXCHANGE_PostPursesMergeHandle *pch, 374 TALER_EXCHANGE_PostPursesMergeCallback cb, 375 TALER_EXCHANGE_POST_PURSES_MERGE_RESULT_CLOSURE *cb_cls) 376 { 377 char arg_str[sizeof (pch->purse_pub) * 2 + 32]; 378 CURL *eh; 379 380 pch->cb = cb; 381 pch->cb_cls = cb_cls; 382 383 { 384 char pub_str[sizeof (pch->purse_pub) * 2]; 385 char *end; 386 387 end = GNUNET_STRINGS_data_to_string ( 388 &pch->purse_pub, 389 sizeof (pch->purse_pub), 390 pub_str, 391 sizeof (pub_str)); 392 *end = '\0'; 393 GNUNET_snprintf (arg_str, 394 sizeof (arg_str), 395 "purses/%s/merge", 396 pub_str); 397 } 398 pch->url = TALER_url_join (pch->base_url, 399 arg_str, 400 NULL); 401 if (NULL == pch->url) 402 { 403 GNUNET_break (0); 404 return TALER_EC_GENERIC_CONFIGURATION_INVALID; 405 } 406 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 407 "URL for purse merge: `%s'\n", 408 pch->url); 409 { 410 struct TALER_NormalizedPayto reserve_url; 411 412 reserve_url = TALER_reserve_make_payto (pch->provider_url, 413 &pch->reserve_pub); 414 if (NULL == reserve_url.normalized_payto) 415 { 416 GNUNET_break (0); 417 return TALER_EC_GENERIC_ALLOCATION_FAILURE; 418 } 419 TALER_wallet_purse_merge_sign (reserve_url, 420 pch->merge_timestamp, 421 &pch->purse_pub, 422 &pch->merge_priv, 423 &pch->merge_sig); 424 pch->body = GNUNET_JSON_PACK ( 425 TALER_JSON_pack_normalized_payto ("payto_uri", 426 reserve_url), 427 GNUNET_JSON_pack_data_auto ("merge_sig", 428 &pch->merge_sig), 429 GNUNET_JSON_pack_data_auto ("reserve_sig", 430 &pch->reserve_sig), 431 GNUNET_JSON_pack_timestamp ("merge_timestamp", 432 pch->merge_timestamp)); 433 GNUNET_free (reserve_url.normalized_payto); 434 } 435 436 eh = TALER_EXCHANGE_curl_easy_get_ (pch->url); 437 if ( (NULL == eh) || 438 (GNUNET_OK != 439 TALER_curl_easy_post (&pch->post_ctx, 440 eh, 441 pch->body)) ) 442 { 443 GNUNET_break (0); 444 if (NULL != eh) 445 curl_easy_cleanup (eh); 446 return TALER_EC_GENERIC_CURL_ALLOCATION_FAILURE; 447 } 448 pch->job = GNUNET_CURL_job_add2 (pch->ctx, 449 eh, 450 pch->post_ctx.headers, 451 &handle_purse_merge_finished, 452 pch); 453 if (NULL == pch->job) 454 return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE; 455 return TALER_EC_NONE; 456 } 457 458 459 void 460 TALER_EXCHANGE_post_purses_merge_cancel ( 461 struct TALER_EXCHANGE_PostPursesMergeHandle *pch) 462 { 463 if (NULL != pch->job) 464 { 465 GNUNET_CURL_job_cancel (pch->job); 466 pch->job = NULL; 467 } 468 GNUNET_free (pch->url); 469 GNUNET_free (pch->base_url); 470 GNUNET_free (pch->provider_url); 471 TALER_curl_easy_post_finished (&pch->post_ctx); 472 TALER_EXCHANGE_keys_decref (pch->keys); 473 json_decref (pch->body); 474 GNUNET_free (pch); 475 } 476 477 478 /* end of exchange_api_post-purses-PURSE_PUB-merge.c */