From ce3d7c360b7b0bd5cbdbe93ec86e1cb3c9108ea9 Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Tue, 31 May 2016 14:32:06 +0200 Subject: add support for /keys cache control (#4036) --- src/exchange-lib/exchange_api_handle.c | 275 +++++++++++++++++++++++++++------ 1 file changed, 232 insertions(+), 43 deletions(-) (limited to 'src/exchange-lib') diff --git a/src/exchange-lib/exchange_api_handle.c b/src/exchange-lib/exchange_api_handle.c index 6de5ee59b..b9104869e 100644 --- a/src/exchange-lib/exchange_api_handle.c +++ b/src/exchange-lib/exchange_api_handle.c @@ -108,6 +108,11 @@ struct TALER_EXCHANGE_Handle */ struct TALER_EXCHANGE_Keys key_data; + /** + * When does @e key_data expire? + */ + struct GNUNET_TIME_Absolute key_data_expiration; + /** * Raw key data of the exchange, only valid if * @e handshake_complete is past stage #MHS_CERT. @@ -144,6 +149,12 @@ struct KeysRequest */ struct GNUNET_CURL_Job *job; + /** + * Expiration time according to "Expire:" header. + * 0 if not provided by the server. + */ + struct GNUNET_TIME_Absolute expire; + }; @@ -485,6 +496,7 @@ decode_keys_json (const json_t *resp_obj, struct GNUNET_HashContext *hash_context; struct TALER_ExchangePublicKeyP pub; + memset (key_data, 0, sizeof (struct TALER_EXCHANGE_Keys)); if (JSON_OBJECT != json_typeof (resp_obj)) return GNUNET_SYSERR; @@ -604,6 +616,58 @@ decode_keys_json (const json_t *resp_obj, } +/** + * Free key data object. + * + * @param key_data data to free (pointer itself excluded) + */ +static void +free_key_data (struct TALER_EXCHANGE_Keys *key_data) +{ + unsigned int i; + + GNUNET_array_grow (key_data->sign_keys, + key_data->num_sign_keys, + 0); + for (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->num_denom_keys, + 0); + GNUNET_array_grow (key_data->auditors, + key_data->num_auditors, + 0); +} + + +/** + * Initiate download of /keys from the exchange. + * + * @param exchange where to download /keys from + */ +static void +request_keys (struct TALER_EXCHANGE_Handle *exchange); + + +/** + * Check if our current response for /keys is valid, and if + * not trigger download. + * + * @param exchange exchange to check keys for + * @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) +{ + if (NULL != exchange->kr) + return GNUNET_TIME_UNIT_ZERO_ABS; + if (0 < GNUNET_TIME_absolute_get_remaining (exchange->key_data_expiration).rel_value_us) + return exchange->key_data_expiration; + request_keys (exchange); + return GNUNET_TIME_UNIT_ZERO_ABS; +} + + /** * Callback used when downloading the reply to a /keys request * is complete. @@ -619,13 +683,16 @@ keys_completed_cb (void *cls, { struct KeysRequest *kr = cls; struct TALER_EXCHANGE_Handle *exchange = kr->exchange; - TALER_EXCHANGE_CertificationCallback cb; + struct TALER_EXCHANGE_Keys kd; + struct TALER_EXCHANGE_Keys kd_old; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received keys from URL `%s' with status %ld.\n", kr->url, response_code); - switch (response_code) { + kd_old = exchange->key_data; + switch (response_code) + { case 0: break; case MHD_HTTP_OK: @@ -635,11 +702,14 @@ keys_completed_cb (void *cls, break; } if (GNUNET_OK != - decode_keys_json (resp_obj, &kr->exchange->key_data)) + decode_keys_json (resp_obj, + &kd)) { response_code = 0; break; } + exchange->key_data = kd; + json_decref (exchange->key_data_raw); exchange->key_data_raw = json_deep_copy (resp_obj); break; default: @@ -655,24 +725,25 @@ keys_completed_cb (void *cls, free_keys_request (kr); exchange->state = MHS_FAILED; /* notify application that we failed */ - if (NULL != (cb = exchange->cert_cb)) - { - exchange->cert_cb = NULL; - cb (exchange->cert_cb_cls, - NULL); - } + exchange->cert_cb (exchange->cert_cb_cls, + NULL); + if (NULL != exchange->key_data_raw) + { + json_decref (exchange->key_data_raw); + exchange->key_data_raw = NULL; + } + free_key_data (&kd_old); return; } + exchange->kr = NULL; + exchange->key_data_expiration = kr->expire; free_keys_request (kr); exchange->state = MHS_CERT; /* notify application about the key information */ - if (NULL != (cb = exchange->cert_cb)) - { - exchange->cert_cb = NULL; - cb (exchange->cert_cb_cls, - &exchange->key_data); - } + exchange->cert_cb (exchange->cert_cb_cls, + &exchange->key_data); + free_key_data (&kd_old); } @@ -730,6 +801,108 @@ MAH_path_to_url (struct TALER_EXCHANGE_Handle *h, } +/** + * 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) +{ + static const char *const days[] = + { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" }; + static const char *const mons[] = + { "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; + struct tm now; + time_t t; + char day[3]; + char mon[3]; + unsigned int i; + unsigned int mday; + unsigned int year; + unsigned int h; + unsigned int m; + unsigned int s; + + if (7 != sscanf (date, + "%3s, %02u %3s %04u %02u:%02u:%02u GMT", + day, + &mday, + mon, + &year, + &h, + &m, + &s)) + return GNUNET_SYSERR; + memset (&now, 0, sizeof (now)); + now.tm_year = year - 1900; + now.tm_mday = mday; + now.tm_hour = h; + now.tm_min = m; + now.tm_sec = s; + now.tm_wday = 7; + for (i=0;i<7;i++) + if (0 == strcasecmp (days[i], day)) + now.tm_wday = i; + now.tm_mon = 12; + for (i=0;i<12;i++) + if (0 == strcasecmp (mons[i], mon)) + now.tm_mon = i; + if ( (7 == now.tm_mday) || + (12 == now.tm_mon) ) + return GNUNET_SYSERR; + t = mktime (&now); + 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 fo 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); + } + GNUNET_free (val); + return total; +} + /* ********************* public API ******************* */ /** @@ -755,40 +928,62 @@ TALER_EXCHANGE_connect (struct GNUNET_CURL_Context *ctx, ...) { struct TALER_EXCHANGE_Handle *exchange; - struct KeysRequest *kr; - CURL *c; 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; + request_keys (exchange); + return exchange; +} + + +/** + * Initiate download of /keys from the exchange. + * + * @param exchange where to download /keys from + */ +static void +request_keys (struct TALER_EXCHANGE_Handle *exchange) +{ + struct KeysRequest *kr; + CURL *eh; + + GNUNET_assert (NULL == exchange->kr); kr = GNUNET_new (struct KeysRequest); kr->exchange = exchange; kr->url = MAH_path_to_url (exchange, "/keys"); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Requesting keys with URL `%s'.\n", kr->url); - c = curl_easy_init (); + eh = curl_easy_init (); GNUNET_assert (CURLE_OK == - curl_easy_setopt (c, + curl_easy_setopt (eh, CURLOPT_VERBOSE, 0)); GNUNET_assert (CURLE_OK == - curl_easy_setopt (c, - CURLOPT_STDERR, - stdout)); + curl_easy_setopt (eh, + CURLOPT_TIMEOUT, + (long) 300)); GNUNET_assert (CURLE_OK == - curl_easy_setopt (c, + curl_easy_setopt (eh, + CURLOPT_HEADERFUNCTION, + &header_cb)); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, + CURLOPT_HEADERDATA, + kr)); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, CURLOPT_URL, kr->url)); kr->job = GNUNET_CURL_job_add (exchange->ctx, - c, + eh, GNUNET_NO, &keys_completed_cb, kr); exchange->kr = kr; - return exchange; } @@ -800,26 +995,18 @@ TALER_EXCHANGE_connect (struct GNUNET_CURL_Context *ctx, void TALER_EXCHANGE_disconnect (struct TALER_EXCHANGE_Handle *exchange) { - unsigned int i; - if (NULL != exchange->kr) { GNUNET_CURL_job_cancel (exchange->kr->job); free_keys_request (exchange->kr); exchange->kr = NULL; } - GNUNET_array_grow (exchange->key_data.sign_keys, - exchange->key_data.num_sign_keys, - 0); - for (i=0;ikey_data.num_denom_keys;i++) - GNUNET_CRYPTO_rsa_public_key_free (exchange->key_data.denom_keys[i].key.rsa_public_key); - GNUNET_array_grow (exchange->key_data.denom_keys, - exchange->key_data.num_denom_keys, - 0); - GNUNET_array_grow (exchange->key_data.auditors, - exchange->key_data.num_auditors, - 0); - json_decref (exchange->key_data_raw); + free_key_data (&exchange->key_data); + if (NULL != exchange->key_data_raw) + { + json_decref (exchange->key_data_raw); + exchange->key_data_raw = NULL; + } GNUNET_free (exchange->url); GNUNET_free (exchange); } @@ -863,7 +1050,7 @@ TALER_EXCHANGE_test_signing_key (const struct TALER_EXCHANGE_Keys *keys, */ const struct TALER_EXCHANGE_DenomPublicKey * TALER_EXCHANGE_get_denomination_key (const struct TALER_EXCHANGE_Keys *keys, - const struct TALER_DenominationPublicKey *pk) + const struct TALER_DenominationPublicKey *pk) { unsigned int i; @@ -884,7 +1071,7 @@ TALER_EXCHANGE_get_denomination_key (const struct TALER_EXCHANGE_Keys *keys, */ const struct TALER_EXCHANGE_DenomPublicKey * TALER_EXCHANGE_get_denomination_key_by_hash (const struct TALER_EXCHANGE_Keys *keys, - const struct GNUNET_HashCode *hc) + const struct GNUNET_HashCode *hc) { unsigned int i; @@ -904,8 +1091,9 @@ TALER_EXCHANGE_get_denomination_key_by_hash (const struct TALER_EXCHANGE_Keys *k * @return the exchange's key set */ const struct TALER_EXCHANGE_Keys * -TALER_EXCHANGE_get_keys (const struct TALER_EXCHANGE_Handle *exchange) +TALER_EXCHANGE_get_keys (struct TALER_EXCHANGE_Handle *exchange) { + (void) TALER_EXCHANGE_check_keys_current (exchange); return &exchange->key_data; } @@ -918,8 +1106,9 @@ TALER_EXCHANGE_get_keys (const struct TALER_EXCHANGE_Handle *exchange) * @return the exchange's keys in raw JSON */ json_t * -TALER_EXCHANGE_get_keys_raw (const struct TALER_EXCHANGE_Handle *exchange) +TALER_EXCHANGE_get_keys_raw (struct TALER_EXCHANGE_Handle *exchange) { + (void) TALER_EXCHANGE_check_keys_current (exchange); return json_deep_copy (exchange->key_data_raw); } -- cgit v1.2.3