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authorChristian Grothoff <christian@grothoff.org>2015-09-14 15:29:40 +0200
committerChristian Grothoff <christian@grothoff.org>2015-09-14 15:29:40 +0200
commit899f2b4070ec04af0e0040f6b7fa62d3d860ffee (patch)
tree5fa896e5939a871166cd2ed336c03b4baf35cb12
parent6501118f6c345fc1a4810611f8631172b105c279 (diff)
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implement /wire api (#3947)
-rw-r--r--src/include/taler_mint_service.h82
-rw-r--r--src/mint-lib/Makefile.am1
-rw-r--r--src/mint-lib/mint_api_wire.c611
3 files changed, 694 insertions, 0 deletions
diff --git a/src/include/taler_mint_service.h b/src/include/taler_mint_service.h
index 02407a3a..3f89b074 100644
--- a/src/include/taler_mint_service.h
+++ b/src/include/taler_mint_service.h
@@ -353,6 +353,88 @@ TALER_MINT_get_denomination_key (const struct TALER_MINT_Keys *keys,
const struct TALER_DenominationPublicKey *pk);
+/* ********************* /wire *********************** */
+
+
+/**
+ * @brief A Wire format inquiry handle
+ */
+struct TALER_MINT_WireHandle;
+
+
+/**
+ * Callbacks of this type are used to serve the result of submitting a
+ * wire format inquiry request to a mint.
+ *
+ * The callback is invoked multiple times, once for each supported @a
+ * method. Finally, it is invoked one more time with cls/0/NULL/NULL
+ * to indicate the end of the iteration. If any request fails to
+ * generate a valid response from the mint, @a http_status will also
+ * be zero and the iteration will also end. Thus, the iteration
+ * always ends with a final call with an @a http_status of 0. If the
+ * @a http_status is already 0 on the first call, then the response to
+ * the /wire request was invalid. Later, clients can tell the
+ * difference between @a http_status of 0 indicating a failed
+ * /wire/method request and a regular end of the iteration by @a
+ * method being non-NULL. If the mint simply correctly asserts that
+ * it does not support any methods, @a method will be NULL but the @a
+ * http_status will be #MHD_HTTP_OK for the first call (followed by a
+ * cls/0/NULL/NULL call to signal the end of the iteration).
+ *
+ * @param cls closure
+ * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful request;
+ * 0 if the mint's reply is bogus (fails to follow the protocol)
+ * @param method wire format method supported, i.e. "test" or "sepa", or NULL
+ * if already the /wire request failed.
+ * @param obj the received JSON reply, if successful this should be the wire
+ * format details as provided by /wire/METHOD/, or NULL if the
+ * reply was not in JSON format (in this case, the client might
+ * want to do an HTTP request to /wire/METHOD/ with a browser to
+ * provide more information to the user about the @a method).
+ */
+typedef void
+(*TALER_MINT_WireResultCallback) (void *cls,
+ unsigned int http_status,
+ const char *method,
+ json_t *obj);
+
+
+/**
+ * Obtain information about a mint's wire instructions.
+ * A mint may provide wire instructions for creating
+ * a reserve. The wire instructions also indicate
+ * which wire formats merchants may use with the mint.
+ * This API is typically used by a wallet for wiring
+ * funds, and possibly by a merchant to determine
+ * supported wire formats.
+ *
+ * Note that while we return the (main) response verbatim to the
+ * caller for further processing, we do already verify that the
+ * response is well-formed (i.e. that signatures included in the
+ * response are all valid). If the mint's reply is not well-formed,
+ * we return an HTTP status code of zero to @a cb.
+ *
+ * @param mint the mint handle; the mint must be ready to operate
+ * @param wire_cb the callback to call when a reply for this request is available
+ * @param wire_cb_cls closure for the above callback
+ * @return a handle for this request
+ */
+struct TALER_MINT_WireHandle *
+TALER_MINT_wire (struct TALER_MINT_Handle *mint,
+ TALER_MINT_WireResultCallback wire_cb,
+ void *wire_cb_cls);
+
+
+/**
+ * Cancel a wire information request. This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param wh the wire information request handle
+ */
+void
+TALER_MINT_wire_cancel (struct TALER_MINT_WireHandle *wh);
+
+
/* ********************* /deposit *********************** */
diff --git a/src/mint-lib/Makefile.am b/src/mint-lib/Makefile.am
index 0cb83dac..2729177f 100644
--- a/src/mint-lib/Makefile.am
+++ b/src/mint-lib/Makefile.am
@@ -22,6 +22,7 @@ libtalermint_la_SOURCES = \
mint_api_deposit.c \
mint_api_refresh.c \
mint_api_refresh_link.c \
+ mint_api_wire.c \
mint_api_withdraw.c
libtalermint_la_LIBADD = \
diff --git a/src/mint-lib/mint_api_wire.c b/src/mint-lib/mint_api_wire.c
new file mode 100644
index 00000000..7641af7a
--- /dev/null
+++ b/src/mint-lib/mint_api_wire.c
@@ -0,0 +1,611 @@
+/*
+ This file is part of TALER
+ Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
+
+ 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, If not, see
+ <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file mint-lib/mint_api_wire.c
+ * @brief Implementation of the /wire request of the mint's HTTP API
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <curl/curl.h>
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_mint_service.h"
+#include "mint_api_common.h"
+#include "mint_api_json.h"
+#include "mint_api_context.h"
+#include "mint_api_handle.h"
+#include "taler_signatures.h"
+
+
+/**
+ * @brief A Wire Handle
+ */
+struct TALER_MINT_WireHandle
+{
+
+ /**
+ * The connection to mint this request handle will use
+ */
+ struct TALER_MINT_Handle *mint;
+
+ /**
+ * The url for this request.
+ */
+ char *url;
+
+ /**
+ * Handle for the request.
+ */
+ struct MAC_Job *job;
+
+ /**
+ * Function to call with the result.
+ */
+ TALER_MINT_WireResultCallback cb;
+
+ /**
+ * Closure for @a cb.
+ */
+ void *cb_cls;
+
+ /**
+ * Download buffer
+ */
+ struct MAC_DownloadBuffer db;
+
+ /**
+ * Set to the "methods" JSON array returned by the
+ * /wire request.
+ */
+ json_t *methods;
+
+ /**
+ * Current iteration offset in the @e methods array.
+ */
+ unsigned int methods_off;
+
+};
+
+
+/**
+ * Verify that the signature on the "200 OK" response
+ * for /wire/sepa from the mint is valid.
+ *
+ * @param wh wire handle
+ * @param json json reply with the signature
+ * @return #GNUNET_SYSERR if @a json is invalid,
+ * #GNUNET_NO if the method is unknown,
+ * #GNUNET_OK if the json is valid
+ */
+static int
+verify_wire_sepa_signature_ok (const struct TALER_MINT_WireHandle *wh,
+ json_t *json)
+{
+ struct TALER_MasterSignatureP mint_sig;
+ struct TALER_MasterWireSepaDetailsPS mp;
+ const char *receiver_name;
+ const char *iban;
+ const char *bic;
+ const struct TALER_MINT_Keys *key_state;
+ struct GNUNET_HashContext *hc;
+ struct MAJ_Specification spec[] = {
+ MAJ_spec_fixed_auto ("sig", &mint_sig),
+ MAJ_spec_string ("receiver_name", &receiver_name),
+ MAJ_spec_string ("iban", &iban),
+ MAJ_spec_string ("bic", &bic),
+ MAJ_spec_end
+ };
+
+ if (GNUNET_OK !=
+ MAJ_parse_json (json,
+ spec))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+
+ key_state = TALER_MINT_get_keys (wh->mint);
+ mp.purpose.purpose = htonl (TALER_SIGNATURE_MASTER_SEPA_DETAILS);
+ mp.purpose.size = htonl (sizeof (struct TALER_MasterWireSepaDetailsPS));
+ hc = GNUNET_CRYPTO_hash_context_start ();
+ GNUNET_CRYPTO_hash_context_read (hc,
+ receiver_name,
+ strlen (receiver_name) + 1);
+ GNUNET_CRYPTO_hash_context_read (hc,
+ iban,
+ strlen (iban) + 1);
+ GNUNET_CRYPTO_hash_context_read (hc,
+ bic,
+ strlen (bic) + 1);
+ GNUNET_CRYPTO_hash_context_finish (hc,
+ &mp.h_sepa_details);
+
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_SEPA_DETAILS,
+ &mp.purpose,
+ &mint_sig.eddsa_signature,
+ &key_state->master_pub.eddsa_pub))
+ {
+ GNUNET_break_op (0);
+ MAJ_parse_free (spec);
+ return GNUNET_SYSERR;
+ }
+ MAJ_parse_free (spec);
+ return GNUNET_OK;
+}
+
+
+/**
+ * Verify that the signature on the "200 OK" response
+ * for /wire/METHOD from the mint is valid.
+ *
+ * @param wh wire handle with key material
+ * @param method method to verify the reply for
+ * @param json json reply with the signature
+ * @return #GNUNET_SYSERR if @a json is invalid,
+ * #GNUNET_NO if the method is unknown,
+ * #GNUNET_OK if the json is valid
+ */
+static int
+verify_wire_method_signature_ok (const struct TALER_MINT_WireHandle *wh,
+ const char *method,
+ json_t *json)
+{
+ struct
+ {
+ /**
+ * Name fo the method.
+ */
+ const char *method;
+
+ /**
+ * Handler to invoke to verify signature.
+ *
+ * @param wh wire handle with key material
+ * @param json json reply with signature to verify
+ */
+ int (*handler)(const struct TALER_MINT_WireHandle *wh,
+ json_t *json);
+ } handlers[] = {
+ { "sepa", &verify_wire_sepa_signature_ok },
+ { NULL, NULL }
+ };
+ unsigned int i;
+
+ for (i=0;NULL != handlers[i].method; i++)
+ if (0 == strcasecmp (handlers[i].method,
+ method))
+ return handlers[i].handler (wh,
+ json);
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Wire transfer method `%s' not supported\n",
+ method);
+ return GNUNET_NO;
+}
+
+
+/**
+ * Perform the next /wire/method request or signal
+ * the end of the iteration.
+ *
+ * @param wh the wire handle
+ * @return a handle for this request
+ */
+static void
+request_wire_method (struct TALER_MINT_WireHandle *wh);
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /wire/METHOD request.
+ *
+ * @param cls the `struct TALER_MINT_WireHandle`
+ * @param eh the curl request handle
+ */
+static void
+handle_wire_method_finished (void *cls,
+ CURL *eh)
+{
+ struct TALER_MINT_WireHandle *wh = cls;
+ long response_code;
+ json_t *json;
+
+ wh->job = NULL;
+ json = MAC_download_get_result (&wh->db,
+ eh,
+ &response_code);
+ switch (response_code)
+ {
+ case 0:
+ break;
+ case MHD_HTTP_OK:
+ {
+ const char *method;
+
+ method = json_string_value (json_array_get (wh->methods,
+ wh->methods_off - 1));
+ if (GNUNET_OK !=
+ verify_wire_method_signature_ok (wh,
+ method,
+ json))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ break;
+ }
+ break;
+ }
+ case MHD_HTTP_FOUND:
+ /* /wire/test returns a 302 redirect, we should just give
+ this information back to the callback below */
+ break;
+ case MHD_HTTP_BAD_REQUEST:
+ /* This should never happen, either us or the mint is buggy
+ (or API version conflict); just pass JSON reply to the application */
+ break;
+ case MHD_HTTP_NOT_FOUND:
+ /* Nothing really to verify, this should never
+ happen, we should pass the JSON reply to the application */
+ break;
+ case MHD_HTTP_INTERNAL_SERVER_ERROR:
+ /* Server had an internal issue; we should retry, but this API
+ leaves this to the application */
+ break;
+ default:
+ /* unexpected response code */
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ "Unexpected response code %u\n",
+ response_code);
+ GNUNET_break (0);
+ response_code = 0;
+ break;
+ }
+ if (0 == response_code)
+ {
+ /* signal end of iteration */
+ wh->cb (wh->cb_cls,
+ 0,
+ NULL,
+ NULL);
+ json_decref (json);
+ TALER_MINT_wire_cancel (wh);
+ }
+ /* pass on successful reply */
+ wh->cb (wh->cb_cls,
+ response_code,
+ NULL,
+ json);
+ /* trigger request for the next /wire/method */
+ request_wire_method (wh);
+}
+
+
+/**
+ * Perform the next /wire/method request or signal
+ * the end of the iteration.
+ *
+ * @param wh the wire handle
+ * @return a handle for this request
+ */
+static void
+request_wire_method (struct TALER_MINT_WireHandle *wh)
+{
+ struct TALER_MINT_Context *ctx;
+ CURL *eh;
+ char *path;
+
+ if (json_array_size (wh->methods) <= wh->methods_off)
+ {
+ /* we are done, signal end of iteration */
+ wh->cb (wh->cb_cls,
+ 0,
+ NULL,
+ NULL);
+ TALER_MINT_wire_cancel (wh);
+ return;
+ }
+ GNUNET_free_non_null (wh->db.buf);
+ wh->db.buf = NULL;
+ wh->db.buf_size = 0;
+ wh->db.eno = 0;
+ GNUNET_free_non_null (wh->url);
+ GNUNET_asprintf (&path,
+ "/wire/%s",
+ json_string_value (json_array_get (wh->methods,
+ wh->methods_off++)));
+ wh->url = MAH_path_to_url (wh->mint,
+ path);
+ GNUNET_free (path);
+
+ eh = curl_easy_init ();
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_URL,
+ wh->url));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_WRITEFUNCTION,
+ &MAC_download_cb));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_WRITEDATA,
+ &wh->db));
+ ctx = MAH_handle_to_context (wh->mint);
+ wh->job = MAC_job_add (ctx,
+ eh,
+ GNUNET_YES,
+ &handle_wire_method_finished,
+ wh);
+}
+
+
+/**
+ * Verify that the signature on the "200 OK" response
+ * for /wire from the mint is valid.
+ *
+ * @param wh wire handle
+ * @param json json reply with the signature
+ * @return NULL if @a json is invalid, otherwise the
+ * "methods" array (with an RC of 1)
+ */
+static json_t *
+verify_wire_signature_ok (const struct TALER_MINT_WireHandle *wh,
+ json_t *json)
+{
+ struct TALER_MintSignatureP mint_sig;
+ struct TALER_MintPublicKeyP mint_pub;
+ struct TALER_MintWireSupportMethodsPS mp;
+ json_t *methods;
+ const struct TALER_MINT_Keys *key_state;
+ struct GNUNET_HashContext *hc;
+ struct MAJ_Specification spec[] = {
+ MAJ_spec_fixed_auto ("sig", &mint_sig),
+ MAJ_spec_fixed_auto ("pub", &mint_pub),
+ MAJ_spec_json ("methods", &methods),
+ MAJ_spec_end
+ };
+ unsigned int i;
+
+ if (GNUNET_OK !=
+ MAJ_parse_json (json,
+ spec))
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ if (! json_is_array (methods))
+ {
+ GNUNET_break_op (0);
+ MAJ_parse_free (spec);
+ return NULL;
+ }
+
+ key_state = TALER_MINT_get_keys (wh->mint);
+ if (GNUNET_OK !=
+ TALER_MINT_test_signing_key (key_state,
+ &mint_pub))
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ hc = GNUNET_CRYPTO_hash_context_start ();
+ for (i=0;i<json_array_size (methods);i++)
+ {
+ const json_t *element = json_array_get (methods, i);
+ const char *method;
+
+ if (! json_is_string (element))
+ {
+ GNUNET_CRYPTO_hash_context_abort (hc);
+ GNUNET_break_op (0);
+ MAJ_parse_free (spec);
+ return NULL;
+ }
+ method = json_string_value (element);
+ GNUNET_CRYPTO_hash_context_read (hc,
+ method,
+ strlen (method) + 1);
+ }
+ mp.purpose.purpose = htonl (TALER_SIGNATURE_MINT_WIRE_TYPES);
+ mp.purpose.size = htonl (sizeof (struct TALER_MintWireSupportMethodsPS));
+ GNUNET_CRYPTO_hash_context_finish (hc,
+ &mp.h_wire_types);
+
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MINT_WIRE_TYPES,
+ &mp.purpose,
+ &mint_sig.eddsa_signature,
+ &mint_pub.eddsa_pub))
+ {
+ GNUNET_break_op (0);
+ MAJ_parse_free (spec);
+ return NULL;
+ }
+ return methods;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /wire request.
+ *
+ * @param cls the `struct TALER_MINT_WireHandle`
+ * @param eh the curl request handle
+ */
+static void
+handle_wire_finished (void *cls,
+ CURL *eh)
+{
+ struct TALER_MINT_WireHandle *wh = cls;
+ long response_code;
+ json_t *json;
+
+ wh->job = NULL;
+ json = MAC_download_get_result (&wh->db,
+ eh,
+ &response_code);
+ switch (response_code)
+ {
+ case 0:
+ break;
+ case MHD_HTTP_OK:
+ {
+ json_t *methods;
+
+ if (NULL ==
+ (methods = verify_wire_signature_ok (wh,
+ json)))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ break;
+ }
+ wh->methods = methods;
+ request_wire_method (wh);
+ return;
+ }
+ break;
+ case MHD_HTTP_BAD_REQUEST:
+ /* This should never happen, either us or the mint is buggy
+ (or API version conflict); just pass JSON reply to the application */
+ break;
+ case MHD_HTTP_NOT_FOUND:
+ /* Nothing really to verify, this should never
+ happen, we should pass the JSON reply to the application */
+ break;
+ case MHD_HTTP_INTERNAL_SERVER_ERROR:
+ /* Server had an internal issue; we should retry, but this API
+ leaves this to the application */
+ break;
+ default:
+ /* unexpected response code */
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ "Unexpected response code %u\n",
+ response_code);
+ GNUNET_break (0);
+ response_code = 0;
+ break;
+ }
+ if (0 != response_code)
+ {
+ /* pass on successful reply */
+ wh->cb (wh->cb_cls,
+ response_code,
+ NULL,
+ json);
+ }
+ /* signal end of iteration */
+ wh->cb (wh->cb_cls,
+ 0,
+ NULL,
+ NULL);
+ json_decref (json);
+ TALER_MINT_wire_cancel (wh);
+}
+
+
+/**
+ * Obtain information about a mint's wire instructions.
+ * A mint may provide wire instructions for creating
+ * a reserve. The wire instructions also indicate
+ * which wire formats merchants may use with the mint.
+ * This API is typically used by a wallet for wiring
+ * funds, and possibly by a merchant to determine
+ * supported wire formats.
+ *
+ * Note that while we return the (main) response verbatim to the
+ * caller for further processing, we do already verify that the
+ * response is well-formed (i.e. that signatures included in the
+ * response are all valid). If the mint's reply is not well-formed,
+ * we return an HTTP status code of zero to @a cb.
+ *
+ * @param mint the mint handle; the mint must be ready to operate
+ * @param wire_cb the callback to call when a reply for this request is available
+ * @param wire_cb_cls closure for the above callback
+ * @return a handle for this request
+ */
+struct TALER_MINT_WireHandle *
+TALER_MINT_wire (struct TALER_MINT_Handle *mint,
+ TALER_MINT_WireResultCallback wire_cb,
+ void *wire_cb_cls)
+{
+ struct TALER_MINT_WireHandle *wh;
+ struct TALER_MINT_Context *ctx;
+ CURL *eh;
+
+ if (GNUNET_YES !=
+ MAH_handle_is_ready (mint))
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ wh = GNUNET_new (struct TALER_MINT_WireHandle);
+ wh->mint = mint;
+ wh->cb = wire_cb;
+ wh->cb_cls = wire_cb_cls;
+ wh->url = MAH_path_to_url (mint, "/wire");
+
+ eh = curl_easy_init ();
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_URL,
+ wh->url));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_WRITEFUNCTION,
+ &MAC_download_cb));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_WRITEDATA,
+ &wh->db));
+ ctx = MAH_handle_to_context (mint);
+ wh->job = MAC_job_add (ctx,
+ eh,
+ GNUNET_YES,
+ &handle_wire_finished,
+ wh);
+ return wh;
+}
+
+
+/**
+ * Cancel a wire information request. This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param wire the wire information request handle
+ */
+void
+TALER_MINT_wire_cancel (struct TALER_MINT_WireHandle *wire)
+{
+ if (NULL != wire->job)
+ {
+ MAC_job_cancel (wire->job);
+ wire->job = NULL;
+ }
+ if (NULL != wire->methods)
+ {
+ json_decref (wire->methods);
+ wire->methods = NULL;
+ }
+ GNUNET_free_non_null (wire->db.buf);
+ GNUNET_free (wire->url);
+ GNUNET_free (wire);
+}
+
+
+/* end of mint_api_wire.c */