/* This file is part of TALER Copyright (C) 2014-2018 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 */ /** * @file lib/exchange_api_handle.c * @brief Implementation of the "handle" component of the exchange's HTTP API * @author Sree Harsha Totakura * @author Christian Grothoff */ #include "platform.h" #include #include #include "taler_json_lib.h" #include "taler_exchange_service.h" #include "taler_auditor_service.h" #include "taler_signatures.h" #include "exchange_api_handle.h" #include "exchange_api_curl_defaults.h" #include "backoff.h" #include "taler_curl_lib.h" /** * Which version of the Taler protocol is implemented * by this library? Used to determine compatibility. */ #define EXCHANGE_PROTOCOL_CURRENT 8 /** * How many versions are we backwards compatible with? */ #define EXCHANGE_PROTOCOL_AGE 0 /** * Current version for (local) JSON serialization of persisted * /keys data. */ #define EXCHANGE_SERIALIZATION_FORMAT_VERSION 0 /** * Log error related to CURL operations. * * @param type log level * @param function which function failed to run * @param code what was the curl error code */ #define CURL_STRERROR(type, function, code) \ GNUNET_log (type, "Curl function `%s' has failed at `%s:%d' with error: %s", \ function, __FILE__, __LINE__, curl_easy_strerror (code)); /** * Stages of initialization for the `struct TALER_EXCHANGE_Handle` */ enum ExchangeHandleState { /** * Just allocated. */ MHS_INIT = 0, /** * Obtained the exchange's certification data and keys. */ MHS_CERT = 1, /** * Failed to initialize (fatal). */ MHS_FAILED = 2 }; /** * Data for the request to get the /keys of a exchange. */ struct KeysRequest; /** * Entry in DLL of auditors used by an exchange. */ struct TEAH_AuditorListEntry { /** * Next pointer of DLL. */ struct TEAH_AuditorListEntry *next; /** * Prev pointer of DLL. */ struct TEAH_AuditorListEntry *prev; /** * Base URL of the auditor. */ char *auditor_url; /** * Handle to the auditor. */ struct TALER_AUDITOR_Handle *ah; /** * Head of DLL of interactions with this auditor. */ struct TEAH_AuditorInteractionEntry *ai_head; /** * Tail of DLL of interactions with this auditor. */ struct TEAH_AuditorInteractionEntry *ai_tail; /** * Public key of the auditor. */ struct TALER_AuditorPublicKeyP auditor_pub; /** * Flag indicating that the auditor is available and that protocol * version compatibility is given. */ int is_up; }; /** * Handle to the exchange */ struct TALER_EXCHANGE_Handle { /** * The context of this handle */ struct GNUNET_CURL_Context *ctx; /** * The URL of the exchange (i.e. "http://exchange.taler.net/") */ char *url; /** * Function to call with the exchange's certification data, * NULL if this has already been done. */ TALER_EXCHANGE_CertificationCallback cert_cb; /** * Closure to pass to @e cert_cb. */ void *cert_cb_cls; /** * Data for the request to get the /keys of a exchange, * NULL once we are past stage #MHS_INIT. */ struct KeysRequest *kr; /** * Task for retrying /keys request. */ struct GNUNET_SCHEDULER_Task *retry_task; /** * Raw key data of the exchange, only valid if * @e handshake_complete is past stage #MHS_CERT. */ json_t *key_data_raw; /** * Head of DLL of auditors of this exchange. */ struct TEAH_AuditorListEntry *auditors_head; /** * Tail of DLL of auditors of this exchange. */ struct TEAH_AuditorListEntry *auditors_tail; /** * Key data of the exchange, only valid if * @e handshake_complete is past stage #MHS_CERT. */ struct TALER_EXCHANGE_Keys key_data; /** * Retry /keys frequency. */ struct GNUNET_TIME_Relative retry_delay; /** * When does @e key_data expire? */ struct GNUNET_TIME_Absolute key_data_expiration; /** * Stage of the exchange's initialization routines. */ enum ExchangeHandleState state; /** * If #GNUNET_YES, use fake now given by the user, in * request of "/keys". */ int with_now; /** * Fake now given by the user. */ struct GNUNET_TIME_Absolute now; }; /* ***************** Internal /keys fetching ************* */ /** * Data for the request to get the /keys of a exchange. */ struct KeysRequest { /** * The connection to exchange this request handle will use */ struct TALER_EXCHANGE_Handle *exchange; /** * The url for this handle */ char *url; /** * Entry for this request with the `struct GNUNET_CURL_Context`. */ struct GNUNET_CURL_Job *job; /** * Expiration time according to "Expire:" header. * 0 if not provided by the server. */ struct GNUNET_TIME_Absolute expire; }; /** * Signature of functions called with the result from our call to the * auditor's /deposit-confirmation handler. * * @param cls closure of type `struct TEAH_AuditorInteractionEntry *` * @param hr HTTP response */ void TEAH_acc_confirmation_cb (void *cls, const struct TALER_AUDITOR_HttpResponse *hr) { struct TEAH_AuditorInteractionEntry *aie = cls; struct TEAH_AuditorListEntry *ale = aie->ale; if (MHD_HTTP_OK != hr->http_status) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Failed to submit deposit confirmation to auditor `%s' with HTTP status %d (EC: %d). This is acceptable if it does not happen often.\n", ale->auditor_url, hr->http_status, hr->ec); } GNUNET_CONTAINER_DLL_remove (ale->ai_head, ale->ai_tail, aie); GNUNET_free (aie); } /** * Iterate over all available auditors for @a h, calling * @a ac and giving it a chance to start a deposit * confirmation interaction. * * @param h exchange to go over auditors for * @param ac function to call per auditor * @param ac_cls closure for @a ac */ void TEAH_get_auditors_for_dc (struct TALER_EXCHANGE_Handle *h, TEAH_AuditorCallback ac, void *ac_cls) { if (NULL == h->auditors_head) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, "No auditor available for exchange `%s'. Not submitting deposit confirmations.\n", h->url); return; } for (struct TEAH_AuditorListEntry *ale = h->auditors_head; NULL != ale; ale = ale->next) { struct TEAH_AuditorInteractionEntry *aie; if (GNUNET_NO == ale->is_up) continue; aie = ac (ac_cls, ale->ah, &ale->auditor_pub); if (NULL != aie) { aie->ale = ale; GNUNET_CONTAINER_DLL_insert (ale->ai_head, ale->ai_tail, aie); } } } /** * Release memory occupied by a keys request. Note that this does not * cancel the request itself. * * @param kr request to free */ static void free_keys_request (struct KeysRequest *kr) { GNUNET_free (kr->url); GNUNET_free (kr); } #define EXITIF(cond) \ do { \ if (cond) { GNUNET_break (0); goto EXITIF_exit; } \ } while (0) /** * Parse a exchange's signing key encoded in JSON. * * @param[out] sign_key where to return the result * @param check_sigs should we check signatures? * @param[in] sign_key_obj json to parse * @param master_key master key to use to verify signature * @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is * invalid or the json malformed. */ static int parse_json_signkey (struct TALER_EXCHANGE_SigningPublicKey *sign_key, int check_sigs, json_t *sign_key_obj, const struct TALER_MasterPublicKeyP *master_key) { struct TALER_MasterSignatureP sign_key_issue_sig; struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto ("master_sig", &sign_key_issue_sig), GNUNET_JSON_spec_fixed_auto ("key", &sign_key->key), TALER_JSON_spec_absolute_time ("stamp_start", &sign_key->valid_from), TALER_JSON_spec_absolute_time ("stamp_expire", &sign_key->valid_until), TALER_JSON_spec_absolute_time ("stamp_end", &sign_key->valid_legal), GNUNET_JSON_spec_end () }; if (GNUNET_OK != GNUNET_JSON_parse (sign_key_obj, spec, NULL, NULL)) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (! check_sigs) return GNUNET_OK; { struct TALER_ExchangeSigningKeyValidityPS sign_key_issue = { .purpose.purpose = htonl (TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY), .purpose.size = htonl (sizeof (sign_key_issue)), .signkey_pub = sign_key->key, .master_public_key = *master_key, .start = GNUNET_TIME_absolute_hton (sign_key->valid_from), .expire = GNUNET_TIME_absolute_hton (sign_key->valid_until), .end = GNUNET_TIME_absolute_hton (sign_key->valid_legal) }; if (GNUNET_OK != GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY, &sign_key_issue, &sign_key_issue_sig.eddsa_signature, &master_key->eddsa_pub)) { GNUNET_break_op (0); return GNUNET_SYSERR; } } sign_key->master_sig = sign_key_issue_sig; return GNUNET_OK; } /** * Parse a exchange's denomination key encoded in JSON. * * @param[out] denom_key where to return the result * @param check_sigs should we check signatures? * @param[in] denom_key_obj json to parse * @param master_key master key to use to verify signature * @param hash_context where to accumulate data for signature verification * @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is * invalid or the json malformed. */ static int parse_json_denomkey (struct TALER_EXCHANGE_DenomPublicKey *denom_key, int check_sigs, json_t *denom_key_obj, struct TALER_MasterPublicKeyP *master_key, struct GNUNET_HashContext *hash_context) { struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto ("master_sig", &denom_key->master_sig), TALER_JSON_spec_absolute_time ("stamp_expire_deposit", &denom_key->expire_deposit), TALER_JSON_spec_absolute_time ("stamp_expire_withdraw", &denom_key->withdraw_valid_until), TALER_JSON_spec_absolute_time ("stamp_start", &denom_key->valid_from), TALER_JSON_spec_absolute_time ("stamp_expire_legal", &denom_key->expire_legal), TALER_JSON_spec_amount ("value", &denom_key->value), TALER_JSON_spec_amount ("fee_withdraw", &denom_key->fee_withdraw), TALER_JSON_spec_amount ("fee_deposit", &denom_key->fee_deposit), TALER_JSON_spec_amount ("fee_refresh", &denom_key->fee_refresh), TALER_JSON_spec_amount ("fee_refund", &denom_key->fee_refund), GNUNET_JSON_spec_rsa_public_key ("denom_pub", &denom_key->key.rsa_public_key), GNUNET_JSON_spec_end () }; if (GNUNET_OK != GNUNET_JSON_parse (denom_key_obj, spec, NULL, NULL)) { GNUNET_break_op (0); return GNUNET_SYSERR; } GNUNET_CRYPTO_rsa_public_key_hash (denom_key->key.rsa_public_key, &denom_key->h_key); if (NULL != hash_context) GNUNET_CRYPTO_hash_context_read (hash_context, &denom_key->h_key, sizeof (struct GNUNET_HashCode)); if (! check_sigs) return GNUNET_OK; { struct TALER_DenominationKeyValidityPS denom_key_issue = { .purpose.purpose = htonl (TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY), .purpose.size = htonl (sizeof (denom_key_issue)), .master = *master_key, .denom_hash = denom_key->h_key, .start = GNUNET_TIME_absolute_hton (denom_key->valid_from), .expire_withdraw = GNUNET_TIME_absolute_hton (denom_key->withdraw_valid_until), .expire_deposit = GNUNET_TIME_absolute_hton (denom_key->expire_deposit), .expire_legal = GNUNET_TIME_absolute_hton (denom_key->expire_legal) }; TALER_amount_hton (&denom_key_issue.value, &denom_key->value); TALER_amount_hton (&denom_key_issue.fee_withdraw, &denom_key->fee_withdraw); TALER_amount_hton (&denom_key_issue.fee_deposit, &denom_key->fee_deposit); TALER_amount_hton (&denom_key_issue.fee_refresh, &denom_key->fee_refresh); TALER_amount_hton (&denom_key_issue.fee_refund, &denom_key->fee_refund); EXITIF (GNUNET_SYSERR == GNUNET_CRYPTO_eddsa_verify ( TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY, &denom_key_issue, &denom_key->master_sig.eddsa_signature, &master_key->eddsa_pub)); } return GNUNET_OK; EXITIF_exit: /* invalidate denom_key, just to be sure */ memset (denom_key, 0, sizeof (*denom_key)); GNUNET_JSON_parse_free (spec); return GNUNET_SYSERR; } /** * Parse a exchange's auditor information encoded in JSON. * * @param[out] auditor where to return the result * @param check_sigs should we check signatures * @param[in] auditor_obj json to parse * @param key_data information about denomination keys * @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is * invalid or the json malformed. */ static int parse_json_auditor (struct TALER_EXCHANGE_AuditorInformation *auditor, int check_sigs, json_t *auditor_obj, const struct TALER_EXCHANGE_Keys *key_data) { json_t *keys; json_t *key; unsigned int len; unsigned int off; unsigned int i; const char *auditor_url; struct TALER_ExchangeKeyValidityPS kv; struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto ("auditor_pub", &auditor->auditor_pub), GNUNET_JSON_spec_string ("auditor_url", &auditor_url), GNUNET_JSON_spec_json ("denomination_keys", &keys), GNUNET_JSON_spec_end () }; if (GNUNET_OK != GNUNET_JSON_parse (auditor_obj, spec, NULL, NULL)) { GNUNET_break_op (0); return GNUNET_SYSERR; } auditor->auditor_url = GNUNET_strdup (auditor_url); kv.purpose.purpose = htonl (TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS); kv.purpose.size = htonl (sizeof (struct TALER_ExchangeKeyValidityPS)); GNUNET_CRYPTO_hash (auditor_url, strlen (auditor_url) + 1, &kv.auditor_url_hash); kv.master = key_data->master_pub; len = json_array_size (keys); auditor->denom_keys = GNUNET_new_array (len, struct TALER_EXCHANGE_AuditorDenominationInfo); off = 0; json_array_foreach (keys, i, key) { struct TALER_AuditorSignatureP auditor_sig; struct GNUNET_HashCode denom_h; const struct TALER_EXCHANGE_DenomPublicKey *dk; unsigned int dk_off; struct GNUNET_JSON_Specification kspec[] = { GNUNET_JSON_spec_fixed_auto ("auditor_sig", &auditor_sig), GNUNET_JSON_spec_fixed_auto ("denom_pub_h", &denom_h), GNUNET_JSON_spec_end () }; if (GNUNET_OK != GNUNET_JSON_parse (key, kspec, NULL, NULL)) { GNUNET_break_op (0); continue; } dk = NULL; dk_off = UINT_MAX; for (unsigned int j = 0; jnum_denom_keys; j++) { if (0 == GNUNET_memcmp (&denom_h, &key_data->denom_keys[j].h_key)) { dk = &key_data->denom_keys[j]; dk_off = j; break; } } if (NULL == dk) { GNUNET_break_op (0); continue; } if (check_sigs) { kv.start = GNUNET_TIME_absolute_hton (dk->valid_from); kv.expire_withdraw = GNUNET_TIME_absolute_hton (dk->withdraw_valid_until); kv.expire_deposit = GNUNET_TIME_absolute_hton (dk->expire_deposit); kv.expire_legal = GNUNET_TIME_absolute_hton (dk->expire_legal); TALER_amount_hton (&kv.value, &dk->value); TALER_amount_hton (&kv.fee_withdraw, &dk->fee_withdraw); TALER_amount_hton (&kv.fee_deposit, &dk->fee_deposit); TALER_amount_hton (&kv.fee_refresh, &dk->fee_refresh); TALER_amount_hton (&kv.fee_refund, &dk->fee_refund); kv.denom_hash = dk->h_key; if (GNUNET_OK != GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS, &kv, &auditor_sig.eddsa_sig, &auditor->auditor_pub.eddsa_pub)) { GNUNET_break_op (0); GNUNET_JSON_parse_free (spec); return GNUNET_SYSERR; } } auditor->denom_keys[off].denom_key_offset = dk_off; auditor->denom_keys[off].auditor_sig = auditor_sig; off++; } auditor->num_denom_keys = off; GNUNET_JSON_parse_free (spec); return GNUNET_OK; } /** * Function called with information about the auditor. Marks an * auditor as 'up'. * * @param cls closure, a `struct TEAH_AuditorListEntry *` * @param hr http response from the auditor * @param vi basic information about the auditor * @param compat protocol compatibility information */ static void auditor_version_cb ( void *cls, const struct TALER_AUDITOR_HttpResponse *hr, const struct TALER_AUDITOR_VersionInformation *vi, enum TALER_AUDITOR_VersionCompatibility compat) { struct TEAH_AuditorListEntry *ale = cls; if (NULL == vi) { /* In this case, we don't mark the auditor as 'up' */ GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Auditor `%s' gave unexpected version response.\n", ale->auditor_url); return; } if (0 != (TALER_AUDITOR_VC_INCOMPATIBLE & compat)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Auditor `%s' runs incompatible protocol version!\n", ale->auditor_url); if (0 != (TALER_AUDITOR_VC_OLDER & compat)) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Auditor `%s' runs outdated protocol version!\n", ale->auditor_url); } if (0 != (TALER_AUDITOR_VC_NEWER & compat)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Auditor `%s' runs more recent incompatible version. We should upgrade!\n", ale->auditor_url); } return; } ale->is_up = GNUNET_YES; } /** * Recalculate our auditor list, we got /keys and it may have * changed. * * @param exchange exchange for which to update the list. */ static void update_auditors (struct TALER_EXCHANGE_Handle *exchange) { struct TALER_EXCHANGE_Keys *kd = &exchange->key_data; TALER_LOG_DEBUG ("Updating auditors\n"); for (unsigned int i = 0; inum_auditors; i++) { /* Compare auditor data from /keys with auditor data * from owned exchange structures. */ struct TALER_EXCHANGE_AuditorInformation *auditor = &kd->auditors[i]; struct TEAH_AuditorListEntry *ale = NULL; for (struct TEAH_AuditorListEntry *a = exchange->auditors_head; NULL != a; a = a->next) { if (0 == GNUNET_memcmp (&auditor->auditor_pub, &a->auditor_pub)) { ale = a; break; } } if (NULL != ale) continue; /* found, no need to add */ /* new auditor, add */ TALER_LOG_DEBUG ("Found new auditor!\n"); ale = GNUNET_new (struct TEAH_AuditorListEntry); ale->auditor_pub = auditor->auditor_pub; ale->auditor_url = GNUNET_strdup (auditor->auditor_url); GNUNET_CONTAINER_DLL_insert (exchange->auditors_head, exchange->auditors_tail, ale); ale->ah = TALER_AUDITOR_connect (exchange->ctx, ale->auditor_url, &auditor_version_cb, ale); } } /** * Compare two denomination keys. Ignores revocation data. * * @param denom1 first denomination key * @param denom2 second denomination key * @return 0 if the two keys are equal (not necessarily * the same object), 1 otherwise. */ static unsigned int denoms_cmp (struct TALER_EXCHANGE_DenomPublicKey *denom1, struct TALER_EXCHANGE_DenomPublicKey *denom2) { struct GNUNET_CRYPTO_RsaPublicKey *tmp1; struct GNUNET_CRYPTO_RsaPublicKey *tmp2; int r1; int r2; int ret; /* First check if pub is the same. */ if (0 != GNUNET_CRYPTO_rsa_public_key_cmp (denom1->key.rsa_public_key, denom2->key.rsa_public_key)) return 1; tmp1 = denom1->key.rsa_public_key; tmp2 = denom2->key.rsa_public_key; r1 = denom1->revoked; r2 = denom2->revoked; denom1->key.rsa_public_key = NULL; denom2->key.rsa_public_key = NULL; /* Then proceed with the rest of the object. */ ret = GNUNET_memcmp (denom1, denom2); denom1->revoked = r1; denom2->revoked = r2; denom1->key.rsa_public_key = tmp1; denom2->key.rsa_public_key = tmp2; return ret; } /** * Decode the JSON in @a resp_obj from the /keys response * and store the data in the @a key_data. * * @param[in] resp_obj JSON object to parse * @param check_sig true if we should check the signature * @param[out] key_data where to store the results we decoded * @param[out] vc where to store version compatibility data * @return #GNUNET_OK on success, #GNUNET_SYSERR on error * (malformed JSON) */ static int decode_keys_json (const json_t *resp_obj, bool check_sig, struct TALER_EXCHANGE_Keys *key_data, enum TALER_EXCHANGE_VersionCompatibility *vc) { struct TALER_ExchangeSignatureP sig; struct GNUNET_HashContext *hash_context; struct TALER_ExchangePublicKeyP pub; struct GNUNET_JSON_Specification mspec[] = { GNUNET_JSON_spec_fixed_auto ("eddsa_sig", &sig), GNUNET_JSON_spec_fixed_auto ("eddsa_pub", &pub), /* sig and pub must be first, as we skip those if check_sig is false! */ GNUNET_JSON_spec_fixed_auto ("master_public_key", &key_data->master_pub), TALER_JSON_spec_absolute_time ("list_issue_date", &key_data->list_issue_date), TALER_JSON_spec_relative_time ("reserve_closing_delay", &key_data->reserve_closing_delay), GNUNET_JSON_spec_end () }; if (JSON_OBJECT != json_typeof (resp_obj)) { GNUNET_break_op (0); return GNUNET_SYSERR; } /* check the version */ { const char *ver; unsigned int age; unsigned int revision; unsigned int current; struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_string ("version", &ver), GNUNET_JSON_spec_end () }; if (GNUNET_OK != GNUNET_JSON_parse (resp_obj, spec, NULL, NULL)) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (3 != sscanf (ver, "%u:%u:%u", ¤t, &revision, &age)) { GNUNET_break_op (0); return GNUNET_SYSERR; } *vc = TALER_EXCHANGE_VC_MATCH; if (EXCHANGE_PROTOCOL_CURRENT < current) { *vc |= TALER_EXCHANGE_VC_NEWER; if (EXCHANGE_PROTOCOL_CURRENT < current - age) *vc |= TALER_EXCHANGE_VC_INCOMPATIBLE; } if (EXCHANGE_PROTOCOL_CURRENT > current) { *vc |= TALER_EXCHANGE_VC_OLDER; if (EXCHANGE_PROTOCOL_CURRENT - EXCHANGE_PROTOCOL_AGE > current) *vc |= TALER_EXCHANGE_VC_INCOMPATIBLE; } key_data->version = GNUNET_strdup (ver); } hash_context = NULL; EXITIF (GNUNET_OK != GNUNET_JSON_parse (resp_obj, (check_sig) ? mspec : &mspec[2], NULL, NULL)); /* parse the master public key and issue date of the response */ if (check_sig) hash_context = GNUNET_CRYPTO_hash_context_start (); /* parse the signing keys */ { json_t *sign_keys_array; json_t *sign_key_obj; unsigned int index; EXITIF (NULL == (sign_keys_array = json_object_get (resp_obj, "signkeys"))); EXITIF (JSON_ARRAY != json_typeof (sign_keys_array)); EXITIF (0 == (key_data->num_sign_keys = json_array_size (sign_keys_array))); key_data->sign_keys = GNUNET_new_array (key_data->num_sign_keys, struct TALER_EXCHANGE_SigningPublicKey); json_array_foreach (sign_keys_array, index, sign_key_obj) { EXITIF (GNUNET_SYSERR == parse_json_signkey (&key_data->sign_keys[index], check_sig, sign_key_obj, &key_data->master_pub)); } } /* parse the denomination keys, merging with the possibly EXISTING array as required (/keys cherry picking) */ { json_t *denom_keys_array; json_t *denom_key_obj; unsigned int index; EXITIF (NULL == (denom_keys_array = json_object_get (resp_obj, "denoms"))); EXITIF (JSON_ARRAY != json_typeof (denom_keys_array)); json_array_foreach (denom_keys_array, index, denom_key_obj) { struct TALER_EXCHANGE_DenomPublicKey dk; int found = GNUNET_NO; memset (&dk, 0, sizeof (dk)); EXITIF (GNUNET_SYSERR == parse_json_denomkey (&dk, check_sig, denom_key_obj, &key_data->master_pub, hash_context)); for (unsigned int j = 0; jnum_denom_keys; j++) { if (0 == denoms_cmp (&dk, &key_data->denom_keys[j])) { found = GNUNET_YES; break; } } if (GNUNET_YES == found) { /* 0:0:0 did not support /keys cherry picking */ TALER_LOG_DEBUG ("Skipping denomination key: already know it\n"); GNUNET_CRYPTO_rsa_public_key_free (dk.key.rsa_public_key); continue; } if (key_data->denom_keys_size == key_data->num_denom_keys) GNUNET_array_grow (key_data->denom_keys, key_data->denom_keys_size, key_data->denom_keys_size * 2 + 2); key_data->denom_keys[key_data->num_denom_keys++] = dk; /* Update "last_denom_issue_date" */ TALER_LOG_DEBUG ("Adding denomination key that is valid_from %s\n", GNUNET_STRINGS_absolute_time_to_string (dk.valid_from)); key_data->last_denom_issue_date = GNUNET_TIME_absolute_max (key_data->last_denom_issue_date, dk.valid_from); }; } /* parse the auditor information */ { json_t *auditors_array; json_t *auditor_info; unsigned int index; EXITIF (NULL == (auditors_array = json_object_get (resp_obj, "auditors"))); EXITIF (JSON_ARRAY != json_typeof (auditors_array)); /* Merge with the existing auditor information we have (/keys cherry picking) */ json_array_foreach (auditors_array, index, auditor_info) { struct TALER_EXCHANGE_AuditorInformation ai; int found = GNUNET_NO; memset (&ai, 0, sizeof (ai)); EXITIF (GNUNET_SYSERR == parse_json_auditor (&ai, check_sig, auditor_info, key_data)); for (unsigned int j = 0; jnum_auditors; j++) { struct TALER_EXCHANGE_AuditorInformation *aix = &key_data->auditors[j]; if (0 == GNUNET_memcmp (&ai.auditor_pub, &aix->auditor_pub)) { found = GNUNET_YES; /* Merge denomination key signatures of downloaded /keys into existing auditor information 'aix'. */ TALER_LOG_DEBUG ( "Merging %u new audited keys with %u known audited keys\n", aix->num_denom_keys, ai.num_denom_keys); GNUNET_array_concatenate (aix->denom_keys, aix->num_denom_keys, ai.denom_keys, ai.num_denom_keys); break; } } if (GNUNET_YES == found) { GNUNET_array_grow (ai.denom_keys, ai.num_denom_keys, 0); GNUNET_free (ai.auditor_url); continue; /* we are done */ } if (key_data->auditors_size == key_data->num_auditors) GNUNET_array_grow (key_data->auditors, key_data->auditors_size, key_data->auditors_size * 2 + 2); GNUNET_assert (NULL != ai.auditor_url); key_data->auditors[key_data->num_auditors++] = ai; }; } /* parse the revocation/recoup information */ { json_t *recoup_array; json_t *recoup_info; unsigned int index; if (NULL != (recoup_array = json_object_get (resp_obj, "recoup"))) { EXITIF (JSON_ARRAY != json_typeof (recoup_array)); json_array_foreach (recoup_array, index, recoup_info) { struct GNUNET_HashCode h_denom_pub; struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto ("h_denom_pub", &h_denom_pub), GNUNET_JSON_spec_end () }; EXITIF (GNUNET_OK != GNUNET_JSON_parse (recoup_info, spec, NULL, NULL)); for (unsigned int j = 0; jnum_denom_keys; j++) { if (0 == GNUNET_memcmp (&h_denom_pub, &key_data->denom_keys[j].h_key)) { key_data->denom_keys[j].revoked = GNUNET_YES; break; } } }; } } if (check_sig) { struct TALER_ExchangeKeySetPS ks; /* Validate signature... */ ks.purpose.size = htonl (sizeof (ks)); ks.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_KEY_SET); ks.list_issue_date = GNUNET_TIME_absolute_hton (key_data->list_issue_date); GNUNET_CRYPTO_hash_context_finish (hash_context, &ks.hc); hash_context = NULL; EXITIF (GNUNET_OK != TALER_EXCHANGE_test_signing_key (key_data, &pub)); EXITIF (GNUNET_OK != GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_KEY_SET, &ks, &sig.eddsa_signature, &pub.eddsa_pub)); } return GNUNET_OK; EXITIF_exit: *vc = TALER_EXCHANGE_VC_PROTOCOL_ERROR; if (NULL != hash_context) GNUNET_CRYPTO_hash_context_abort (hash_context); return GNUNET_SYSERR; } /** * Free key data object. * * @param key_data data to free (pointer itself excluded) */ static void free_key_data (struct TALER_EXCHANGE_Keys *key_data) { GNUNET_array_grow (key_data->sign_keys, key_data->num_sign_keys, 0); for (unsigned int i = 0; inum_denom_keys; i++) GNUNET_CRYPTO_rsa_public_key_free ( key_data->denom_keys[i].key.rsa_public_key); GNUNET_array_grow (key_data->denom_keys, key_data->denom_keys_size, 0); for (unsigned int i = 0; inum_auditors; i++) { GNUNET_array_grow (key_data->auditors[i].denom_keys, key_data->auditors[i].num_denom_keys, 0); GNUNET_free (key_data->auditors[i].auditor_url); } GNUNET_array_grow (key_data->auditors, key_data->auditors_size, 0); GNUNET_free (key_data->version); key_data->version = NULL; } /** * Initiate download of /keys from the exchange. * * @param cls exchange where to download /keys from */ static void request_keys (void *cls); /** * Set the fake now to be used when requesting "/keys". * * @param exchange exchange handle. * @param now fake now to use. Note: this value will be * used _until_ its use will be unset via @a TALER_EXCHANGE_unset_now() */ void TALER_EXCHANGE_set_now (struct TALER_EXCHANGE_Handle *exchange, struct GNUNET_TIME_Absolute now) { exchange->with_now = GNUNET_YES; exchange->now = now; } /** * Unset the fake now to be used when requesting "/keys". * * @param exchange exchange handle. */ void TALER_EXCHANGE_unset_now (struct TALER_EXCHANGE_Handle *exchange) { exchange->with_now = GNUNET_NO; } /** * Let the user set the last valid denomination time manually. * * @param exchange the exchange handle. * @param last_denom_new new last denomination time. */ void TALER_EXCHANGE_set_last_denom (struct TALER_EXCHANGE_Handle *exchange, struct GNUNET_TIME_Absolute last_denom_new) { exchange->key_data.last_denom_issue_date = last_denom_new; } /** * Check if our current response for /keys is valid, and if * not trigger download. * * @param exchange exchange to check keys for * @param flags options controlling when to download what * @return until when the response is current, 0 if we are re-downloading */ struct GNUNET_TIME_Absolute TALER_EXCHANGE_check_keys_current (struct TALER_EXCHANGE_Handle *exchange, enum TALER_EXCHANGE_CheckKeysFlags flags) { bool force_download = 0 != (flags & TALER_EXCHANGE_CKF_FORCE_DOWNLOAD); bool pull_all_keys = 0 != (flags & TALER_EXCHANGE_CKF_PULL_ALL_KEYS); if (NULL != exchange->kr) return GNUNET_TIME_UNIT_ZERO_ABS; if (pull_all_keys) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Forcing re-download of all exchange keys\n"); GNUNET_break (GNUNET_YES == force_download); exchange->state = MHS_INIT; } if ( (! force_download) && (0 < GNUNET_TIME_absolute_get_remaining ( exchange->key_data_expiration).rel_value_us) ) return exchange->key_data_expiration; if (NULL == exchange->retry_task) exchange->retry_task = GNUNET_SCHEDULER_add_now (&request_keys, exchange); return GNUNET_TIME_UNIT_ZERO_ABS; } /** * Callback used when downloading the reply to a /keys request * is complete. * * @param cls the `struct KeysRequest` * @param response_code HTTP response code, 0 on error * @param resp_obj parsed JSON result, NULL on error */ static void keys_completed_cb (void *cls, long response_code, const void *resp_obj) { struct KeysRequest *kr = cls; struct TALER_EXCHANGE_Handle *exchange = kr->exchange; struct TALER_EXCHANGE_Keys kd; struct TALER_EXCHANGE_Keys kd_old; enum TALER_EXCHANGE_VersionCompatibility vc; const json_t *j = resp_obj; struct TALER_EXCHANGE_HttpResponse hr = { .reply = j, .http_status = (unsigned int) response_code }; GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Received keys from URL `%s' with status %ld.\n", kr->url, response_code); kd_old = exchange->key_data; memset (&kd, 0, sizeof (struct TALER_EXCHANGE_Keys)); vc = TALER_EXCHANGE_VC_PROTOCOL_ERROR; switch (response_code) { case 0: free_keys_request (kr); exchange->kr = NULL; GNUNET_assert (NULL == exchange->retry_task); exchange->retry_delay = EXCHANGE_LIB_BACKOFF (exchange->retry_delay); exchange->retry_task = GNUNET_SCHEDULER_add_delayed (exchange->retry_delay, &request_keys, exchange); return; case MHD_HTTP_OK: if (NULL == j) { response_code = 0; break; } /* We keep the denomination keys and auditor signatures from the previous iteration (/keys cherry picking) */ kd.num_denom_keys = kd_old.num_denom_keys; kd.last_denom_issue_date = kd_old.last_denom_issue_date; GNUNET_array_grow (kd.denom_keys, kd.denom_keys_size, kd.num_denom_keys); /* First make a shallow copy, we then need another pass for the RSA key... */ memcpy (kd.denom_keys, kd_old.denom_keys, kd_old.num_denom_keys * sizeof (struct TALER_EXCHANGE_DenomPublicKey)); for (unsigned int i = 0; iauditor_pub = aold->auditor_pub; GNUNET_assert (NULL != aold->auditor_url); anew->auditor_url = GNUNET_strdup (aold->auditor_url); GNUNET_array_grow (anew->denom_keys, anew->num_denom_keys, aold->num_denom_keys); memcpy (anew->denom_keys, aold->denom_keys, aold->num_denom_keys * sizeof (struct TALER_EXCHANGE_AuditorDenominationInfo)); } /* Old auditors got just copied into new ones. */ if (GNUNET_OK != decode_keys_json (j, true, &kd, &vc)) { TALER_LOG_ERROR ("Could not decode /keys response\n"); hr.http_status = 0; hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED; for (unsigned int i = 0; idenom_keys, anew->num_denom_keys, 0); GNUNET_free (anew->auditor_url); } GNUNET_free (kd.auditors); kd.auditors = NULL; kd.num_auditors = 0; for (unsigned int i = 0; ikey_data_raw); exchange->key_data_raw = json_deep_copy (j); exchange->retry_delay = GNUNET_TIME_UNIT_ZERO; break; default: hr.ec = TALER_JSON_get_error_code (j); hr.hint = TALER_JSON_get_error_hint (j); GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Unexpected response code %u/%d\n", (unsigned int) response_code, (int) hr.ec); break; } exchange->key_data = kd; TALER_LOG_DEBUG ("Last DK issue date update to: %s\n", GNUNET_STRINGS_absolute_time_to_string (exchange->key_data.last_denom_issue_date)); if (MHD_HTTP_OK != response_code) { exchange->kr = NULL; free_keys_request (kr); exchange->state = MHS_FAILED; GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Exchange keys download failed\n"); if (NULL != exchange->key_data_raw) { json_decref (exchange->key_data_raw); exchange->key_data_raw = NULL; } free_key_data (&kd_old); /* notify application that we failed */ exchange->cert_cb (exchange->cert_cb_cls, &hr, NULL, vc); return; } exchange->kr = NULL; exchange->key_data_expiration = kr->expire; free_keys_request (kr); exchange->state = MHS_CERT; GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Successfully downloaded exchange's keys\n"); update_auditors (exchange); /* notify application about the key information */ exchange->cert_cb (exchange->cert_cb_cls, &hr, &exchange->key_data, vc); free_key_data (&kd_old); } /* ********************* library internal API ********* */ /** * Get the context of a exchange. * * @param h the exchange handle to query * @return ctx context to execute jobs in */ struct GNUNET_CURL_Context * TEAH_handle_to_context (struct TALER_EXCHANGE_Handle *h) { return h->ctx; } /** * Check if the handle is ready to process requests. * * @param h the exchange handle to query * @return #GNUNET_YES if we are ready, #GNUNET_NO if not */ int TEAH_handle_is_ready (struct TALER_EXCHANGE_Handle *h) { return (MHS_CERT == h->state) ? GNUNET_YES : GNUNET_NO; } /** * Obtain the URL to use for an API request. * * @param h handle for the exchange * @param path Taler API path (i.e. "/reserve/withdraw") * @return the full URL to use with cURL */ char * TEAH_path_to_url (struct TALER_EXCHANGE_Handle *h, const char *path) { char *ret; GNUNET_assert ('/' == path[0]); ret = TALER_url_join (h->url, path + 1, NULL); GNUNET_assert (NULL != ret); return ret; } /** * Parse HTTP timestamp. * * @param date header to parse header * @param at where to write the result * @return #GNUNET_OK on success */ static int parse_date_string (const char *date, struct GNUNET_TIME_Absolute *at) { struct tm now; time_t t; const char *end; memset (&now, 0, sizeof (now)); end = strptime (date, "%a, %d %b %Y %H:%M:%S %Z", /* RFC-1123 standard spec */ &now); if ( (NULL == end) || ( (*end != '\n') && (*end != '\r') ) ) { GNUNET_break_op (0); return GNUNET_SYSERR; } t = mktime (&now); if (((time_t) -1) == t) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "mktime"); return GNUNET_SYSERR; } if (t < 0) t = 0; /* can happen due to timezone issues if date was 1.1.1970 */ at->abs_value_us = 1000LL * 1000LL * t; return GNUNET_OK; } /** * Function called for each header in the HTTP /keys response. * Finds the "Expire:" header and parses it, storing the result * in the "expire" field of the keys request. * * @param buffer header data received * @param size size of an item in @a buffer * @param nitems number of items in @a buffer * @param userdata the `struct KeysRequest` * @return `size * nitems` on success (everything else aborts) */ static size_t header_cb (char *buffer, size_t size, size_t nitems, void *userdata) { struct KeysRequest *kr = userdata; size_t total = size * nitems; char *val; if (total < strlen (MHD_HTTP_HEADER_EXPIRES ": ")) return total; if (0 != strncasecmp (MHD_HTTP_HEADER_EXPIRES ": ", buffer, strlen (MHD_HTTP_HEADER_EXPIRES ": "))) return total; val = GNUNET_strndup (&buffer[strlen (MHD_HTTP_HEADER_EXPIRES ": ")], total - strlen (MHD_HTTP_HEADER_EXPIRES ": ")); if (GNUNET_OK != parse_date_string (val, &kr->expire)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Failed to parse %s-header `%s'\n", MHD_HTTP_HEADER_EXPIRES, val); kr->expire = GNUNET_TIME_UNIT_ZERO_ABS; } GNUNET_free (val); return total; } /* ********************* public API ******************* */ /** * Deserialize the key data and use it to bootstrap @a exchange to * more efficiently recover the state. Errors in @a data must be * tolerated (i.e. by re-downloading instead). * * @param exchange which exchange's key and wire data should be deserialized * @param data the data to deserialize */ static void deserialize_data (struct TALER_EXCHANGE_Handle *exchange, const json_t *data) { enum TALER_EXCHANGE_VersionCompatibility vc; json_t *keys; const char *url; uint32_t version; struct GNUNET_TIME_Absolute expire; struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_uint32 ("version", &version), GNUNET_JSON_spec_json ("keys", &keys), GNUNET_JSON_spec_string ("exchange_url", &url), TALER_JSON_spec_absolute_time ("expire", &expire), GNUNET_JSON_spec_end () }; struct TALER_EXCHANGE_Keys key_data; struct TALER_EXCHANGE_HttpResponse hr = { .ec = TALER_EC_NONE, .http_status = MHD_HTTP_OK, .reply = data }; if (NULL == data) return; if (GNUNET_OK != GNUNET_JSON_parse (data, spec, NULL, NULL)) { GNUNET_break_op (0); return; } if (0 != version) { GNUNET_JSON_parse_free (spec); return; /* unsupported version */ } if (0 != strcmp (url, exchange->url)) { GNUNET_break (0); GNUNET_JSON_parse_free (spec); return; } memset (&key_data, 0, sizeof (struct TALER_EXCHANGE_Keys)); if (GNUNET_OK != decode_keys_json (keys, false, &key_data, &vc)) { GNUNET_break (0); GNUNET_JSON_parse_free (spec); return; } /* decode successful, initialize with the result */ GNUNET_assert (NULL == exchange->key_data_raw); exchange->key_data_raw = json_deep_copy (keys); exchange->key_data = key_data; exchange->key_data_expiration = expire; exchange->state = MHS_CERT; GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Successfully loaded exchange's keys via deserialization\n"); update_auditors (exchange); /* notify application about the key information */ exchange->cert_cb (exchange->cert_cb_cls, &hr, &exchange->key_data, vc); GNUNET_JSON_parse_free (spec); } /** * Serialize the latest key data from @a * exchange to be persisted on disk (to be used with * #TALER_EXCHANGE_OPTION_DATA to more efficiently recover * the state). * * @param exchange which exchange's key and wire data should be * serialized * @return NULL on error (i.e. no current data available); * otherwise JSON object owned by the caller */ json_t * TALER_EXCHANGE_serialize_data (struct TALER_EXCHANGE_Handle *exchange) { const struct TALER_EXCHANGE_Keys *kd = &exchange->key_data; struct GNUNET_TIME_Absolute now; json_t *keys; json_t *signkeys; json_t *denoms; json_t *auditors; now = GNUNET_TIME_absolute_get (); signkeys = json_array (); if (NULL == signkeys) { GNUNET_break (0); return NULL; } for (unsigned int i = 0; inum_sign_keys; i++) { const struct TALER_EXCHANGE_SigningPublicKey *sk = &kd->sign_keys[i]; json_t *signkey; if (now.abs_value_us > sk->valid_until.abs_value_us) continue; /* skip keys that have expired */ signkey = json_pack ("{s:o, s:o, s:o, s:o, s:o}", "key", GNUNET_JSON_from_data_auto (&sk->key), "master_sig", GNUNET_JSON_from_data_auto (&sk->master_sig), "stamp_start", GNUNET_JSON_from_time_abs (sk->valid_from), "stamp_expire", GNUNET_JSON_from_time_abs (sk->valid_until), "stamp_end", GNUNET_JSON_from_time_abs (sk->valid_legal)); if (NULL == signkey) { GNUNET_break (0); continue; } if (0 != json_array_append_new (signkeys, signkey)) { GNUNET_break (0); json_decref (signkey); json_decref (signkeys); return NULL; } } denoms = json_array (); if (NULL == denoms) { GNUNET_break (0); json_decref (signkeys); return NULL; } for (unsigned int i = 0; inum_denom_keys; i++) { const struct TALER_EXCHANGE_DenomPublicKey *dk = &kd->denom_keys[i]; json_t *denom; if (now.abs_value_us > dk->expire_deposit.abs_value_us) continue; /* skip keys that have expired */ denom = json_pack ("{s:o, s:o, s:o, s:o, s:o " ",s:o, s:o, s:o, s:o, s:o " ",s:o}", "stamp_expire_deposit", GNUNET_JSON_from_time_abs (dk->expire_deposit), "stamp_expire_withdraw", GNUNET_JSON_from_time_abs (dk->withdraw_valid_until), "stamp_start", GNUNET_JSON_from_time_abs (dk->valid_from), "stamp_expire_legal", GNUNET_JSON_from_time_abs (dk->expire_legal), "value", TALER_JSON_from_amount (&dk->value), "fee_withdraw", /* #6 */ TALER_JSON_from_amount (&dk->fee_withdraw), "fee_deposit", TALER_JSON_from_amount (&dk->fee_deposit), "fee_refresh", TALER_JSON_from_amount (&dk->fee_refresh), "fee_refund", TALER_JSON_from_amount (&dk->fee_refund), "master_sig", GNUNET_JSON_from_data_auto (&dk->master_sig), /* #10 */ "denom_pub", GNUNET_JSON_from_rsa_public_key ( dk->key.rsa_public_key)); if (NULL == denom) { GNUNET_break (0); continue; } if (0 != json_array_append_new (denoms, denom)) { GNUNET_break (0); json_decref (denom); json_decref (denoms); json_decref (signkeys); return NULL; } } auditors = json_array (); if (NULL == auditors) { GNUNET_break (0); json_decref (denoms); json_decref (signkeys); return NULL; } for (unsigned int i = 0; inum_auditors; i++) { const struct TALER_EXCHANGE_AuditorInformation *ai = &kd->auditors[i]; json_t *a; json_t *adenoms; adenoms = json_array (); if (NULL == adenoms) { GNUNET_break (0); json_decref (denoms); json_decref (signkeys); json_decref (auditors); return NULL; } for (unsigned int j = 0; jnum_denom_keys; j++) { const struct TALER_EXCHANGE_AuditorDenominationInfo *adi = &ai->denom_keys[j]; const struct TALER_EXCHANGE_DenomPublicKey *dk = &kd->denom_keys[adi->denom_key_offset]; json_t *k; if (now.abs_value_us > dk->expire_deposit.abs_value_us) continue; /* skip auditor signatures for denomination keys that have expired */ GNUNET_assert (adi->denom_key_offset < kd->num_denom_keys); k = json_pack ("{s:o, s:o}", "denom_pub_h", GNUNET_JSON_from_data_auto (&dk->h_key), "auditor_sig", GNUNET_JSON_from_data_auto (&adi->auditor_sig)); if (NULL == k) { GNUNET_break (0); json_decref (adenoms); json_decref (denoms); json_decref (signkeys); json_decref (auditors); return NULL; } if (0 != json_array_append_new (adenoms, k)) { GNUNET_break (0); json_decref (k); json_decref (adenoms); json_decref (denoms); json_decref (signkeys); json_decref (auditors); return NULL; } } a = json_pack ("{s:o, s:s, s:o}", "auditor_pub", GNUNET_JSON_from_data_auto (&ai->auditor_pub), "auditor_url", ai->auditor_url, "denomination_keys", adenoms); if (NULL == a) { json_decref (adenoms); json_decref (denoms); json_decref (signkeys); json_decref (auditors); return NULL; } if (0 != json_array_append_new (auditors, a)) { json_decref (a); json_decref (denoms); json_decref (signkeys); json_decref (auditors); return NULL; } } keys = json_pack ("{s:s, s:o, s:o, s:o, s:o" ",s:o, s:o}", /* 1 */ "version", kd->version, "master_public_key", GNUNET_JSON_from_data_auto (&kd->master_pub), "reserve_closing_delay", GNUNET_JSON_from_time_rel (kd->reserve_closing_delay), "list_issue_date", GNUNET_JSON_from_time_abs (kd->list_issue_date), "signkeys", signkeys, /* #6 */ "denoms", denoms, "auditors", auditors); if (NULL == keys) { GNUNET_break (0); return NULL; } return json_pack ("{s:I, s:o, s:s, s:o}", "version", (json_int_t) EXCHANGE_SERIALIZATION_FORMAT_VERSION, "expire", GNUNET_JSON_from_time_abs (exchange->key_data_expiration), "exchange_url", exchange->url, "keys", keys); } /** * Initialise a connection to the exchange. Will connect to the * exchange and obtain information about the exchange's master * public key and the exchange's auditor. * The respective information will be passed to the @a cert_cb * once available, and all future interactions with the exchange * will be checked to be signed (where appropriate) by the * respective master key. * * @param ctx the context * @param url HTTP base URL for the exchange * @param cert_cb function to call with the exchange's * certification information * @param cert_cb_cls closure for @a cert_cb * @param ... list of additional arguments, * terminated by #TALER_EXCHANGE_OPTION_END. * @return the exchange handle; NULL upon error */ struct TALER_EXCHANGE_Handle * TALER_EXCHANGE_connect ( struct GNUNET_CURL_Context *ctx, const char *url, TALER_EXCHANGE_CertificationCallback cert_cb, void *cert_cb_cls, ...) { struct TALER_EXCHANGE_Handle *exchange; va_list ap; enum TALER_EXCHANGE_Option opt; TALER_LOG_DEBUG ("Connecting to the exchange (%s)\n", url); /* Disable 100 continue processing */ GNUNET_break (GNUNET_OK == GNUNET_CURL_append_header (ctx, "Expect:")); exchange = GNUNET_new (struct TALER_EXCHANGE_Handle); exchange->ctx = ctx; exchange->url = GNUNET_strdup (url); exchange->cert_cb = cert_cb; exchange->cert_cb_cls = cert_cb_cls; exchange->retry_task = GNUNET_SCHEDULER_add_now (&request_keys, exchange); va_start (ap, cert_cb_cls); while (TALER_EXCHANGE_OPTION_END != (opt = va_arg (ap, int))) { switch (opt) { case TALER_EXCHANGE_OPTION_END: GNUNET_assert (0); break; case TALER_EXCHANGE_OPTION_DATA: { const json_t *data = va_arg (ap, const json_t *); deserialize_data (exchange, data); break; } default: GNUNET_assert (0); break; } } va_end (ap); return exchange; } /** * Initiate download of /keys from the exchange. * * @param cls exchange where to download /keys from */ static void request_keys (void *cls) { struct TALER_EXCHANGE_Handle *exchange = cls; struct KeysRequest *kr; CURL *eh; char url[200] = "/keys?"; exchange->retry_task = NULL; GNUNET_assert (NULL == exchange->kr); kr = GNUNET_new (struct KeysRequest); kr->exchange = exchange; if (GNUNET_YES == TEAH_handle_is_ready (exchange)) { TALER_LOG_DEBUG ("Last DK issue date (before GETting /keys): %s\n", GNUNET_STRINGS_absolute_time_to_string ( exchange->key_data.last_denom_issue_date)); sprintf (&url[strlen (url)], "last_issue_date=%llu&", (unsigned long long) exchange->key_data.last_denom_issue_date.abs_value_us / 1000000LLU); } if (GNUNET_YES == exchange->with_now) { TALER_LOG_DEBUG ("Faking now to GET /keys: %s\n", GNUNET_STRINGS_absolute_time_to_string (exchange->now)); sprintf (&url[strlen (url)], "now=%llu&", (unsigned long long) exchange->now.abs_value_us / 1000000LLU); } /* Clean the last '&'/'?' sign that we optimistically put. */ url[strlen (url) - 1] = '\0'; kr->url = TEAH_path_to_url (exchange, url); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Requesting keys with URL `%s'.\n", kr->url); eh = TALER_EXCHANGE_curl_easy_get_ (kr->url); if (NULL == eh) { exchange->retry_delay = EXCHANGE_LIB_BACKOFF (exchange->retry_delay); exchange->retry_task = GNUNET_SCHEDULER_add_delayed (exchange->retry_delay, &request_keys, exchange); return; } GNUNET_break (CURLE_OK == curl_easy_setopt (eh, CURLOPT_VERBOSE, 0)); GNUNET_break (CURLE_OK == curl_easy_setopt (eh, CURLOPT_TIMEOUT, (long) 300)); GNUNET_assert (CURLE_OK == curl_easy_setopt (eh, CURLOPT_HEADERFUNCTION, &header_cb)); GNUNET_assert (CURLE_OK == curl_easy_setopt (eh, CURLOPT_HEADERDATA, kr)); kr->job = GNUNET_CURL_job_add_with_ct_json (exchange->ctx, eh, &keys_completed_cb, kr); exchange->kr = kr; } /** * Disconnect from the exchange * * @param exchange the exchange handle */ void TALER_EXCHANGE_disconnect (struct TALER_EXCHANGE_Handle *exchange) { struct TEAH_AuditorListEntry *ale; while (NULL != (ale = exchange->auditors_head)) { struct TEAH_AuditorInteractionEntry *aie; while (NULL != (aie = ale->ai_head)) { GNUNET_assert (aie->ale == ale); GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Not sending deposit confirmation to auditor `%s' due to exchange disconnect\n", ale->auditor_url); TALER_AUDITOR_deposit_confirmation_cancel (aie->dch); GNUNET_CONTAINER_DLL_remove (ale->ai_head, ale->ai_tail, aie); GNUNET_free (aie); } GNUNET_CONTAINER_DLL_remove (exchange->auditors_head, exchange->auditors_tail, ale); TALER_LOG_DEBUG ("Disconnecting the auditor `%s'\n", ale->auditor_url); TALER_AUDITOR_disconnect (ale->ah); GNUNET_free (ale->auditor_url); GNUNET_free (ale); } if (NULL != exchange->kr) { GNUNET_CURL_job_cancel (exchange->kr->job); free_keys_request (exchange->kr); exchange->kr = NULL; } free_key_data (&exchange->key_data); if (NULL != exchange->key_data_raw) { json_decref (exchange->key_data_raw); exchange->key_data_raw = NULL; } if (NULL != exchange->retry_task) { GNUNET_SCHEDULER_cancel (exchange->retry_task); exchange->retry_task = NULL; } GNUNET_free (exchange->url); GNUNET_free (exchange); } /** * Test if the given @a pub is a the current signing key from the exchange * according to @a keys. * * @param keys the exchange's key set * @param pub claimed current online signing key for the exchange * @return #GNUNET_OK if @a pub is (according to /keys) a current signing key */ int TALER_EXCHANGE_test_signing_key (const struct TALER_EXCHANGE_Keys *keys, const struct TALER_ExchangePublicKeyP *pub) { struct GNUNET_TIME_Absolute now; /* we will check using a tolerance of 1h for the time */ now = GNUNET_TIME_absolute_get (); for (unsigned int i = 0; inum_sign_keys; i++) if ( (keys->sign_keys[i].valid_from.abs_value_us <= now.abs_value_us + 60 * 60 * 1000LL * 1000LL) && (keys->sign_keys[i].valid_until.abs_value_us > now.abs_value_us - 60 * 60 * 1000LL * 1000LL) && (0 == GNUNET_memcmp (pub, &keys->sign_keys[i].key)) ) return GNUNET_OK; return GNUNET_SYSERR; } /** * Get exchange's base URL. * * @param exchange exchange handle. * @return the base URL from the handle. */ const char * TALER_EXCHANGE_get_base_url (const struct TALER_EXCHANGE_Handle *exchange) { return exchange->url; } /** * Obtain the denomination key details from the exchange. * * @param keys the exchange's key set * @param pk public key of the denomination to lookup * @return details about the given denomination key, NULL if the key is * not found */ const struct TALER_EXCHANGE_DenomPublicKey * TALER_EXCHANGE_get_denomination_key ( const struct TALER_EXCHANGE_Keys *keys, const struct TALER_DenominationPublicKey *pk) { for (unsigned int i = 0; inum_denom_keys; i++) if (0 == GNUNET_CRYPTO_rsa_public_key_cmp (pk->rsa_public_key, keys->denom_keys[i].key. rsa_public_key)) return &keys->denom_keys[i]; return NULL; } /** * Create a copy of a denomination public key. * * @param key key to copy * @returns a copy, must be freed with #TALER_EXCHANGE_destroy_denomination_key */ struct TALER_EXCHANGE_DenomPublicKey * TALER_EXCHANGE_copy_denomination_key ( const struct TALER_EXCHANGE_DenomPublicKey *key) { struct TALER_EXCHANGE_DenomPublicKey *copy; copy = GNUNET_new (struct TALER_EXCHANGE_DenomPublicKey); *copy = *key; copy->key.rsa_public_key = GNUNET_CRYPTO_rsa_public_key_dup ( key->key.rsa_public_key); return copy; } /** * Destroy a denomination public key. * Should only be called with keys created by #TALER_EXCHANGE_copy_denomination_key. * * @param key key to destroy. */ void TALER_EXCHANGE_destroy_denomination_key ( struct TALER_EXCHANGE_DenomPublicKey *key) { GNUNET_CRYPTO_rsa_public_key_free (key->key.rsa_public_key);; GNUNET_free (key); } /** * Obtain the denomination key details from the exchange. * * @param keys the exchange's key set * @param hc hash of the public key of the denomination to lookup * @return details about the given denomination key */ const struct TALER_EXCHANGE_DenomPublicKey * TALER_EXCHANGE_get_denomination_key_by_hash ( const struct TALER_EXCHANGE_Keys *keys, const struct GNUNET_HashCode *hc) { for (unsigned int i = 0; inum_denom_keys; i++) if (0 == GNUNET_memcmp (hc, &keys->denom_keys[i].h_key)) return &keys->denom_keys[i]; return NULL; } /** * Obtain the keys from the exchange. * * @param exchange the exchange handle * @return the exchange's key set */ const struct TALER_EXCHANGE_Keys * TALER_EXCHANGE_get_keys (struct TALER_EXCHANGE_Handle *exchange) { (void) TALER_EXCHANGE_check_keys_current (exchange, TALER_EXCHANGE_CKF_NONE); return &exchange->key_data; } /** * Obtain the keys from the exchange in the * raw JSON format * * @param exchange the exchange handle * @return the exchange's keys in raw JSON */ json_t * TALER_EXCHANGE_get_keys_raw (struct TALER_EXCHANGE_Handle *exchange) { (void) TALER_EXCHANGE_check_keys_current (exchange, TALER_EXCHANGE_CKF_NONE); return json_deep_copy (exchange->key_data_raw); } /* end of exchange_api_handle.c */