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-rw-r--r--src/include/taler_exchange_service.h79
-rw-r--r--src/include/taler_json_lib.h12
-rw-r--r--src/json/json_helper.c50
-rw-r--r--src/lib/Makefile.am1
-rw-r--r--src/lib/exchange_api_csr.c307
5 files changed, 448 insertions, 1 deletions
diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index caa61c5f1..2dd220293 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -1033,6 +1033,85 @@ void
TALER_EXCHANGE_refund_cancel (struct TALER_EXCHANGE_RefundHandle *refund);
+/* ********************* POST /csr *********************** */
+
+
+/**
+ * @brief A /csr Handle
+ */
+struct TALER_EXCHANGE_CsRHandle;
+
+
+/**
+ * Details about a response for a CS R request.
+ */
+struct TALER_EXCHANGE_CsRResponse
+{
+ /**
+ * HTTP response data.
+ */
+ struct TALER_EXCHANGE_HttpResponse hr;
+
+ /**
+ * Details about the response.
+ */
+ union
+ {
+ /**
+ * Details if the status is #MHD_HTTP_OK.
+ */
+ struct
+ {
+ /**
+ * Signature over the coin.
+ */
+ struct TALER_DenominationCsPublicR r_pubs;
+ } success;
+
+ /**
+ * Details if the status is #MHD_HTTP_GONE.
+ */
+ struct
+ {
+ /* TODO: returning full details is not implemented */
+ } gone;
+
+ } details;
+};
+
+
+/**
+ * Callbacks of this type are used to serve the result of submitting a
+ * CS R request to a exchange.
+ *
+ * @param cls closure
+ * @param csrr response details
+ */
+typedef void
+(*TALER_EXCHANGE_CsRCallback) (void *cls,
+ const struct TALER_EXCHANGE_CsRResponse *csrr);
+
+
+/**
+ * Get a CS R using a /csr request.
+ *
+ * @param exchange the exchange handle; the exchange must be ready to operate
+ * @param pk denomination of coin the R's will be used for
+ * @param nonce public nonce for CS R request
+ * @param res_cb the callback to call when the final result for this request is available
+ * @param res_cb_cls closure for the above callback
+ * @return handle for the operation on success, NULL on error, i.e.
+ * if the inputs are invalid (i.e. denomination key not with this exchange).
+ * In this case, the callback is not called.
+ */
+struct TALER_EXCHANGE_CsRHandle *
+TALER_EXCHANGE_csr (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_EXCHANGE_DenomPublicKey *pk,
+ const struct TALER_WithdrawNonce *nonce,
+ TALER_EXCHANGE_CsRCallback res_cb,
+ void *res_cb_cls);
+
+
/* ********************* GET /reserves/$RESERVE_PUB *********************** */
diff --git a/src/include/taler_json_lib.h b/src/include/taler_json_lib.h
index 51ebe6d90..d243dd723 100644
--- a/src/include/taler_json_lib.h
+++ b/src/include/taler_json_lib.h
@@ -300,6 +300,18 @@ TALER_JSON_spec_i18n_str (const char *name,
/**
+ * Generate line in parser specification for a CS R.
+ *
+ * @param field name of the field
+ * @param r_pub where the r_pub has to be written
+ * @return corresponding field spec
+ */
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_csr (const char *field,
+ struct GNUNET_CRYPTO_CsRPublic *r_pub);
+
+
+/**
* Hash a JSON for binary signing.
*
* See https://tools.ietf.org/html/draft-rundgren-json-canonicalization-scheme-15
diff --git a/src/json/json_helper.c b/src/json/json_helper.c
index 1942d09bd..ef1617ef3 100644
--- a/src/json/json_helper.c
+++ b/src/json/json_helper.c
@@ -658,7 +658,7 @@ TALER_JSON_spec_i18n_str (const char *name,
return ret;
}
-
+//FIXME:
enum GNUNET_GenericReturnValue
TALER_JSON_parse_agemask (const json_t *root,
struct TALER_AgeMask *mask)
@@ -688,6 +688,54 @@ TALER_JSON_parse_agemask (const json_t *root,
}
return GNUNET_OK;
+/**
+ * Parse given JSON object to CS R.
+ *
+ * @param cls closure, NULL
+ * @param root the json object representing data
+ * @param[out] spec where to write the data
+ * @return #GNUNET_OK upon successful parsing; #GNUNET_SYSERR upon error
+ */
+static enum GNUNET_GenericReturnValue
+parse_csr (void *cls,
+ json_t *root,
+ struct GNUNET_JSON_Specification *spec)
+{
+ struct GNUNET_CRYPTO_CsRPublic *r_pub = spec->ptr;
+
+ struct GNUNET_JSON_Specification dspec[] = {
+ GNUNET_JSON_spec_fixed (spec->field, r_pub, sizeof (struct
+ GNUNET_CRYPTO_CsRPublic)),
+ GNUNET_JSON_spec_end ()
+ };
+ const char *emsg;
+ unsigned int eline;
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (root,
+ dspec,
+ &emsg,
+ &eline))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_csr (const char *field,
+ struct GNUNET_CRYPTO_CsRPublic *r_pub)
+{
+ struct GNUNET_JSON_Specification ret = {
+ .parser = &parse_csr,
+ .cleaner = NULL,
+ .field = field,
+ .ptr = r_pub
+ };
+
+ return ret;
}
diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 3398bdf14..fe2a0b6b1 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -24,6 +24,7 @@ libtalerexchange_la_SOURCES = \
exchange_api_auditor_add_denomination.c \
exchange_api_curl_defaults.c exchange_api_curl_defaults.h \
exchange_api_common.c \
+ exchange_api_csr.c \
exchange_api_handle.c exchange_api_handle.h \
exchange_api_deposit.c \
exchange_api_deposits_get.c \
diff --git a/src/lib/exchange_api_csr.c b/src/lib/exchange_api_csr.c
new file mode 100644
index 000000000..fa7010f2c
--- /dev/null
+++ b/src/lib/exchange_api_csr.c
@@ -0,0 +1,307 @@
+/*
+ This file is part of TALER
+ Copyright (C) 2014-2021 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.c
+ * @brief Implementation of /csr 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_CsRHandle
+{
+ /**
+ * The connection to exchange this request handle will use
+ */
+ struct TALER_EXCHANGE_Handle *exchange;
+
+ /**
+ * Function to call with the result.
+ */
+ TALER_EXCHANGE_CsRCallback cb;
+
+ /**
+ * Closure for @a cb.
+ */
+ void *cb_cls;
+
+ /**
+ * Denomination key we are withdrawing.
+ */
+ struct TALER_EXCHANGE_DenomPublicKey pk;
+
+ /**
+ * 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 wh operation handle
+ * @param json reply from the exchange
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
+ */
+static enum GNUNET_GenericReturnValue
+csr_ok (struct TALER_EXCHANGE_CsRHandle *csrh,
+ const json_t *json,
+ struct TALER_EXCHANGE_CsRResponse *csrr)
+{
+ struct GNUNET_JSON_Specification spec[] = {
+ TALER_JSON_spec_csr ("r_pub_0", &csrr->details.success.r_pubs.r_pub[0]),
+ TALER_JSON_spec_csr ("r_pub_1", &csrr->details.success.r_pubs.r_pub[1]),
+ GNUNET_JSON_spec_end ()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (json,
+ spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+
+ /* r_pubs are valid, return it to the application */
+ csrh->cb (csrh->cb_cls,
+ csrr);
+ /* make sure callback isn't called again after return */
+ csrh->cb = NULL;
+ GNUNET_JSON_parse_free (spec);
+ return GNUNET_OK;
+}
+
+
+/**
+ *
+ * Cancel a CS R request. This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param csrh the withdraw handle
+ */
+void
+TALER_EXCHANGE_csr_cancel (struct TALER_EXCHANGE_CsRHandle *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);
+}
+
+
+/**
+ * Function called when we're done processing the HTTP /csr request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_CsRHandle`
+ * @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_CsRHandle *csrh = cls;
+ const json_t *j = response;
+ struct TALER_EXCHANGE_HttpResponse hr = {
+ .reply = j,
+ .http_status = (unsigned int) response_code
+ };
+ struct TALER_EXCHANGE_CsRResponse 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,
+ j,
+ &csrr))
+ {
+ GNUNET_break_op (0);
+ csrr.hr.http_status = 0;
+ csrr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+ break;
+ }
+ GNUNET_assert (NULL == csrh->cb);
+ TALER_EXCHANGE_csr_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. 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;
+ }
+ if (NULL != csrh->cb)
+ {
+ csrh->cb (csrh->cb_cls,
+ &csrr);
+ csrh->cb = NULL;
+ }
+ TALER_EXCHANGE_csr_cancel (csrh);
+}
+
+
+struct TALER_EXCHANGE_CsRHandle *
+TALER_EXCHANGE_csr (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_EXCHANGE_DenomPublicKey *pk,
+ const struct TALER_WithdrawNonce *nonce,
+ TALER_EXCHANGE_CsRCallback res_cb,
+ void *res_cb_cls)
+{
+ struct TALER_EXCHANGE_CsRHandle *csrh;
+
+ if (TALER_DENOMINATION_CS != pk->key.cipher)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+
+ csrh = GNUNET_new (struct TALER_EXCHANGE_CsRHandle);
+ csrh->exchange = exchange;
+ csrh->cb = res_cb;
+ csrh->cb_cls = res_cb_cls;
+ csrh->pk = *pk;
+
+ {
+ json_t *csr_obj;
+
+ csr_obj = GNUNET_JSON_PACK (GNUNET_JSON_pack_data_varsize ("nonce",
+ nonce,
+ sizeof(struct
+ TALER_WithdrawNonce)),
+ GNUNET_JSON_pack_data_varsize ("denom_pub_hash",
+ &pk->h_key,
+ sizeof(struct
+ TALER_DenominationHash)));
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Attempting to request R with denomination public key %s\n",
+ TALER_B2S (&pk->key.details.cs_public_key));
+ csrh->url = TEAH_path_to_url (exchange,
+ "/csr");
+ if (NULL == csrh->url)
+ {
+ json_decref (csr_obj);
+ GNUNET_free (csrh);
+ return NULL;
+ }
+ {
+ CURL *eh;
+ struct GNUNET_CURL_Context *ctx;
+
+ 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,
+ csr_obj)) )
+ {
+ GNUNET_break (0);
+ if (NULL != eh)
+ curl_easy_cleanup (eh);
+ json_decref (csr_obj);
+ GNUNET_free (csrh->url);
+ GNUNET_free (csrh);
+ return NULL;
+ }
+ json_decref (csr_obj);
+ csrh->job = GNUNET_CURL_job_add2 (ctx,
+ eh,
+ csrh->post_ctx.headers,
+ &handle_csr_finished,
+ csrh);
+ }
+ }
+
+ return csrh;
+}