/*
This file is part of TALER
(C) 2014, 2015, 2016, 2018 Taler Systems SA
TALER is free software; you can redistribute it and/or modify
it under the terms of the GNU Affero 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 backend/taler-merchant-httpd_proposal.c
* @brief HTTP serving layer mainly intended to communicate
* with the frontend
* @author Marcello Stanisci
*/
#include "platform.h"
#include
#include
#include
#include "taler-merchant-httpd.h"
#include "taler-merchant-httpd_parsing.h"
#include "taler-merchant-httpd_auditors.h"
#include "taler-merchant-httpd_exchanges.h"
#include "taler-merchant-httpd_responses.h"
/**
* How often do we retry the simple INSERT database transaction?
*/
#define MAX_RETRIES 3
/**
* What is the label under which we find/place the merchant's
* jurisdiction in the locations list by default?
*/
#define STANDARD_LABEL_MERCHANT_JURISDICTION "_mj"
/**
* What is the label under which we find/place the merchant's
* address in the locations list by default?
*/
#define STANDARD_LABEL_MERCHANT_ADDRESS "_ma"
/**
* Check that the given JSON array of products is well-formed.
*
* @param products JSON array to check
* @return #GNUNET_OK if all is fine
*/
static int
check_products (json_t *products)
{
size_t index;
json_t *value;
if (! json_is_array (products))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
json_array_foreach (products, index, value) {
const char *description;
const char *error_name;
unsigned int error_line;
int res;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_string ("description", &description),
/* FIXME: there are other fields in the product specification
that are currently not labeled as optional. Maybe check
those as well, or make them truly optional. */
GNUNET_JSON_spec_end ()
};
/* extract fields we need to sign separately */
res = GNUNET_JSON_parse (value,
spec,
&error_name,
&error_line);
if (GNUNET_OK != res)
{
GNUNET_break (0);
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Product description parsing failed at #%u: %s:%u\n",
(unsigned int) index,
error_name,
error_line);
return GNUNET_SYSERR;
}
GNUNET_JSON_parse_free (spec);
}
return GNUNET_OK;
}
/**
* Information we keep for individual calls
* to requests that parse JSON, but keep no other state.
*/
struct TMH_JsonParseContext
{
/**
* This field MUST be first.
* FIXME: Explain why!
*/
struct TM_HandlerContext hc;
/**
* Placeholder for #TMH_PARSE_post_json() to keep its internal state.
*/
void *json_parse_context;
};
/**
* Custom cleanup routine for a `struct TMH_JsonParseContext`.
*
* @param hc the `struct TMH_JsonParseContext` to clean up.
*/
static void
json_parse_cleanup (struct TM_HandlerContext *hc)
{
struct TMH_JsonParseContext *jpc = (struct TMH_JsonParseContext *) hc;
TMH_PARSE_post_cleanup_callback (jpc->json_parse_context);
GNUNET_free (jpc);
}
/**
* Generate the base URL for the given merchant instance.
*
* @param connection the MHD connection
* @param instance_id the merchant instance ID
* @returns the merchant instance's base URL
*/
static char *
make_merchant_base_url (struct MHD_Connection *connection, const
char *instance_id)
{
const char *host;
const char *forwarded_host;
const char *uri_path;
struct TALER_Buffer buf = { 0 };
if (GNUNET_YES == TALER_mhd_is_https (connection))
TALER_buffer_write_str (&buf, "https://");
else
TALER_buffer_write_str (&buf, "http://");
host = MHD_lookup_connection_value (connection, MHD_HEADER_KIND, "Host");
forwarded_host = MHD_lookup_connection_value (connection, MHD_HEADER_KIND,
"X-Forwarded-Host");
if (NULL != forwarded_host)
{
TALER_buffer_write_str (&buf, forwarded_host);
}
else
{
GNUNET_assert (NULL != host);
TALER_buffer_write_str (&buf, host);
}
uri_path = MHD_lookup_connection_value (connection, MHD_HEADER_KIND,
"X-Forwarded-Prefix");
if (NULL != uri_path)
{
/* Currently the merchant backend is only supported at the root of the path,
this might change in the future. */
GNUNET_assert (0);
}
TALER_buffer_write_path (&buf, "public");
if (0 != strcmp (instance_id, "default"))
{
TALER_buffer_write_path (&buf, "/instances/");
TALER_buffer_write_str (&buf, instance_id);
}
TALER_buffer_write_path (&buf, "");
return TALER_buffer_reap_str (&buf);
}
/**
* Transform an order into a proposal and store it in the
* database. Write the resulting proposal or an error message
* of a MHD connection.
*
* @param connection connection to write the result or error to
* @param root root of the request
* @param order[in] order to process (can be modified)
* @return MHD result code
*/
static int
proposal_put (struct MHD_Connection *connection,
json_t *root,
json_t *order,
const struct MerchantInstance *mi)
{
int res;
struct TALER_Amount total;
const char *order_id;
const char *summary;
const char *fulfillment_url;
json_t *products;
json_t *merchant;
struct GNUNET_TIME_Absolute timestamp;
struct GNUNET_TIME_Absolute refund_deadline;
struct GNUNET_TIME_Absolute wire_transfer_deadline;
struct GNUNET_TIME_Absolute pay_deadline;
struct GNUNET_JSON_Specification spec[] = {
TALER_JSON_spec_amount ("amount", &total),
GNUNET_JSON_spec_string ("order_id", &order_id),
GNUNET_JSON_spec_string ("summary", &summary),
GNUNET_JSON_spec_string ("fulfillment_url",
&fulfillment_url),
/**
* The following entries we don't actually need,
* except to check that the order is well-formed */
GNUNET_JSON_spec_json ("products", &products),
GNUNET_JSON_spec_json ("merchant", &merchant),
GNUNET_JSON_spec_absolute_time ("timestamp",
×tamp),
GNUNET_JSON_spec_absolute_time ("refund_deadline",
&refund_deadline),
GNUNET_JSON_spec_absolute_time ("pay_deadline",
&pay_deadline),
GNUNET_JSON_spec_absolute_time ("wire_transfer_deadline",
&wire_transfer_deadline),
GNUNET_JSON_spec_end ()
};
enum GNUNET_DB_QueryStatus qs;
struct WireMethod *wm;
/* Add order_id if it doesn't exist. */
if (NULL ==
json_string_value (json_object_get (order,
"order_id")))
{
char buf[256];
time_t timer;
struct tm*tm_info;
size_t off;
uint64_t rand;
char *last;
time (&timer);
tm_info = localtime (&timer);
if (NULL == tm_info)
{
return TMH_RESPONSE_reply_internal_error
(connection,
TALER_EC_PROPOSAL_NO_LOCALTIME,
"failed to determine local time");
}
off = strftime (buf,
sizeof (buf),
"%Y.%j",
tm_info);
buf[off++] = '-';
rand = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
UINT64_MAX);
last = GNUNET_STRINGS_data_to_string (&rand,
sizeof (uint64_t),
&buf[off],
sizeof (buf) - off);
*last = '\0';
json_object_set_new (order,
"order_id",
json_string (buf));
}
/* Add timestamp if it doesn't exist */
if (NULL == json_object_get (order,
"timestamp"))
{
struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
(void) GNUNET_TIME_round_abs (&now);
json_object_set_new (order,
"timestamp",
GNUNET_JSON_from_time_abs (now));
}
/* If no refund_deadline given, set one as zero. */
if (NULL == json_object_get (order,
"refund_deadline"))
{
struct GNUNET_TIME_Absolute zero = { 0 };
json_object_set_new (order,
"refund_deadline",
GNUNET_JSON_from_time_abs (zero));
}
if (NULL == json_object_get (order,
"pay_deadline"))
{
struct GNUNET_TIME_Absolute t;
t = GNUNET_TIME_relative_to_absolute (default_pay_deadline);
(void) GNUNET_TIME_round_abs (&t);
json_object_set_new (order,
"pay_deadline",
GNUNET_JSON_from_time_abs (t));
}
if (NULL == json_object_get (order,
"wire_transfer_deadline"))
{
struct GNUNET_TIME_Absolute t;
t = GNUNET_TIME_relative_to_absolute (default_wire_transfer_delay);
(void) GNUNET_TIME_round_abs (&t);
json_object_set_new (order,
"wire_transfer_deadline",
GNUNET_JSON_from_time_abs (t));
}
if (NULL == json_object_get (order,
"max_wire_fee"))
{
json_object_set_new (order,
"max_wire_fee",
TALER_JSON_from_amount
(&default_max_wire_fee));
}
if (NULL == json_object_get (order,
"max_fee"))
{
json_object_set_new (order,
"max_fee",
TALER_JSON_from_amount
(&default_max_deposit_fee));
}
if (NULL == json_object_get (order,
"wire_fee_amortization"))
{
json_object_set_new
(order,
"wire_fee_amortization",
json_integer
((json_int_t) default_wire_fee_amortization));
}
if (NULL == json_object_get (order,
"merchant_base_url"))
{
char *url;
url = make_merchant_base_url (connection, mi->id);
json_object_set_new (order,
"merchant_base_url",
json_string (url));
GNUNET_free (url);
}
if (NULL == json_object_get (order,
"products"))
{
json_object_set_new (order,
"products",
json_array ());
}
/* Fill in merchant information if necessary */
if (NULL == json_object_get (order, "merchant"))
{
const char *mj = NULL;
const char *ma = NULL;
json_t *locations;
char *label;
json_t *jmerchant;
jmerchant = json_object ();
json_object_set_new (jmerchant,
"name",
json_string (mi->name));
json_object_set_new (jmerchant,
"instance",
json_string (mi->id));
locations = json_object_get (order,
"locations");
if (NULL != locations)
{
json_t *loca;
json_t *locj;
/* Handle merchant address */
GNUNET_assert (0 < GNUNET_asprintf (&label,
"%s-address",
mi->id));
loca = json_object_get (default_locations,
label);
if (NULL != loca)
{
loca = json_deep_copy (loca);
ma = STANDARD_LABEL_MERCHANT_ADDRESS;
json_object_set_new (locations,
ma,
loca);
json_object_set_new (jmerchant,
"address",
json_string (ma));
}
GNUNET_free (label);
/* Handle merchant jurisdiction */
GNUNET_assert (0 < GNUNET_asprintf (&label,
"%s-jurisdiction",
mi->id));
locj = json_object_get (default_locations,
label);
if (NULL != locj)
{
if ( (NULL != loca) &&
(1 == json_equal (locj,
loca)) )
{
/* addresses equal, re-use */
mj = ma;
}
else
{
locj = json_deep_copy (locj);
mj = STANDARD_LABEL_MERCHANT_JURISDICTION;
json_object_set_new (locations,
mj,
locj);
}
json_object_set_new (merchant,
"jurisdiction",
json_string (mj));
}
GNUNET_free (label);
} /* have locations */
json_object_set_new (order,
"merchant",
jmerchant);
} /* needed to synthesize merchant info */
/* extract fields we need to sign separately */
res = TMH_PARSE_json_data (connection,
order,
spec);
/* json is malformed */
if (GNUNET_NO == res)
{
return MHD_YES;
}
/* other internal errors might have occurred */
if (GNUNET_SYSERR == res)
{
return TMH_RESPONSE_reply_internal_error
(connection,
TALER_EC_PROPOSAL_ORDER_PARSE_ERROR,
"Impossible to parse the order");
}
if (wire_transfer_deadline.abs_value_us <
refund_deadline.abs_value_us)
{
GNUNET_JSON_parse_free (spec);
return TMH_RESPONSE_reply_arg_invalid
(connection,
TALER_EC_PARAMETER_MALFORMED,
"order:wire_transfer_deadline;order:refund_deadline");
}
/* check contract is well-formed */
if (GNUNET_OK != check_products (products))
{
GNUNET_JSON_parse_free (spec);
return TMH_RESPONSE_reply_arg_invalid
(connection,
TALER_EC_PARAMETER_MALFORMED,
"order:products");
}
/* add fields to the contract that the backend should provide */
json_object_set (order,
"exchanges",
trusted_exchanges);
json_object_set (order,
"auditors",
j_auditors);
/* TODO (#4939-12806): add proper mechanism for
selection of wire method(s) by merchant! */
wm = mi->wm_head;
if (NULL == wm)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"No wire method available for instance '%s'\n", mi->id);
GNUNET_JSON_parse_free (spec);
return TMH_RESPONSE_reply_not_found (connection,
TALER_EC_PROPOSAL_INSTANCE_CONFIGURATION_LACKS_WIRE,
"No wire method configured for instance");
}
json_object_set_new (order,
"H_wire",
GNUNET_JSON_from_data_auto (&wm->h_wire));
json_object_set_new (order,
"wire_method",
json_string (wm->wire_method));
json_object_set_new (order,
"merchant_pub",
GNUNET_JSON_from_data_auto (&mi->pubkey));
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Inserting order '%s' for instance '%s'\n",
order_id,
mi->id);
for (unsigned int i = 0; ipreflight (db->cls);
qs = db->insert_order (db->cls,
order_id,
&mi->pubkey,
timestamp,
order);
if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
break;
}
if (0 > qs)
{
/* Special report if retries insufficient */
if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
{
GNUNET_break (0);
return TMH_RESPONSE_reply_internal_error
(connection,
TALER_EC_PROPOSAL_STORE_DB_ERROR_SOFT,
"db error: could not check for existing order"
" due to repeated soft transaction failure");
}
{
/* Hard error could be constraint violation,
check if order already exists */
json_t *contract_terms = NULL;
db->preflight (db->cls);
qs = db->find_order (db->cls,
&contract_terms,
order_id,
&mi->pubkey);
if (0 < qs)
{
/* Yep, indeed uniqueness constraint violation */
int rv;
char *msg;
GNUNET_JSON_parse_free (spec);
GNUNET_asprintf (&msg,
"order ID `%s' already exists",
order_id);
{
/* Log plenty of details for the admin */
char *js;
js = json_dumps (contract_terms,
JSON_COMPACT);
GNUNET_log
(GNUNET_ERROR_TYPE_ERROR,
_ ("Order ID `%s' already exists with proposal `%s'\n"),
order_id,
js);
free (js);
}
json_decref (contract_terms);
/* contract_terms may be private, only expose
* duplicate order_id to the network */
rv = TMH_RESPONSE_reply_external_error
(connection,
TALER_EC_PROPOSAL_STORE_DB_ERROR_ALREADY_EXISTS,
msg);
GNUNET_free (msg);
return rv;
}
}
/* Other hard transaction error (disk full, etc.) */
GNUNET_JSON_parse_free (spec);
return TMH_RESPONSE_reply_internal_error
(connection,
TALER_EC_PROPOSAL_STORE_DB_ERROR_HARD,
"db error: could not store this proposal's data into db");
}
/* DB transaction succeeded, generate positive response */
res = TMH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:s}",
"order_id",
order_id);
GNUNET_JSON_parse_free (spec);
return res;
}
/**
* Generate a proposal, given its order. In practical terms,
* it adds the fields 'exchanges', 'merchant_pub', and 'H_wire'
* to the order gotten from the frontend. Finally, it signs this
* data, and returns it to the frontend.
*
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure
* (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in
* @a upload_data
* @param mi merchant backend instance, never NULL
* @return MHD result code
*/
int
MH_handler_proposal_put (struct TMH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size,
struct MerchantInstance *mi)
{
int res;
struct TMH_JsonParseContext *ctx;
json_t *root;
json_t *order;
if (NULL == *connection_cls)
{
ctx = GNUNET_new (struct TMH_JsonParseContext);
ctx->hc.cc = &json_parse_cleanup;
*connection_cls = ctx;
}
else
{
ctx = *connection_cls;
}
res = TMH_PARSE_post_json (connection,
&ctx->json_parse_context,
upload_data,
upload_data_size,
&root);
if (GNUNET_SYSERR == res)
return MHD_NO;
/* A error response was already generated */
if ( (GNUNET_NO == res) ||
/* or, need more data to accomplish parsing */
(NULL == root) )
return MHD_YES;
order = json_object_get (root,
"order");
if (NULL == order)
{
res = TMH_RESPONSE_reply_arg_missing
(connection,
TALER_EC_PARAMETER_MISSING,
"order");
}
else
res = proposal_put (connection, root, order, mi);
json_decref (root);
return res;
}
/**
* Manage a GET /proposal request. Query the db and returns the
* proposal's data related to the transaction id given as the URL's
* parameter.
*
* Binds the proposal to a nonce.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @param mi merchant backend instance, never NULL
* @return MHD result code
*/
int
MH_handler_proposal_lookup (struct TMH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size,
struct MerchantInstance *mi)
{
const char *order_id;
const char *nonce;
int res;
enum GNUNET_DB_QueryStatus qs;
json_t *contract_terms;
struct GNUNET_CRYPTO_EddsaSignature merchant_sig;
const char *stored_nonce;
order_id = MHD_lookup_connection_value (connection,
MHD_GET_ARGUMENT_KIND,
"order_id");
if (NULL == order_id)
return TMH_RESPONSE_reply_arg_missing (connection,
TALER_EC_PARAMETER_MISSING,
"order_id");
nonce = MHD_lookup_connection_value (connection,
MHD_GET_ARGUMENT_KIND,
"nonce");
if (NULL == nonce)
return TMH_RESPONSE_reply_arg_missing (connection,
TALER_EC_PARAMETER_MISSING,
"nonce");
db->preflight (db->cls);
qs = db->find_contract_terms (db->cls,
&contract_terms,
order_id,
&mi->pubkey);
if (0 > qs)
{
/* single, read-only SQL statements should never cause
serialization problems */
GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR != qs);
/* Always report on hard error as well to enable diagnostics */
GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
return TMH_RESPONSE_reply_internal_error (connection,
TALER_EC_PROPOSAL_LOOKUP_DB_ERROR,
"An error occurred while retrieving proposal data from db");
}
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
{
struct GNUNET_TIME_Absolute timestamp;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_absolute_time ("timestamp", ×tamp),
GNUNET_JSON_spec_end ()
};
db->preflight (db->cls);
qs = db->find_order (db->cls,
&contract_terms,
order_id,
&mi->pubkey);
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
{
return TMH_RESPONSE_reply_not_found (connection,
TALER_EC_PROPOSAL_LOOKUP_NOT_FOUND,
"unknown order id");
}
GNUNET_assert (NULL != contract_terms);
json_object_set_new (contract_terms,
"nonce",
json_string (nonce));
/* extract fields we need to sign separately */
res = TMH_PARSE_json_data (connection,
contract_terms,
spec);
if (GNUNET_NO == res)
{
return MHD_YES;
}
if (GNUNET_SYSERR == res)
{
return TMH_RESPONSE_reply_internal_error (connection,
TALER_EC_PROPOSAL_ORDER_PARSE_ERROR,
"Impossible to parse the order");
}
for (unsigned int i = 0; ipreflight (db->cls);
qs = db->insert_contract_terms (db->cls,
order_id,
&mi->pubkey,
timestamp,
contract_terms);
if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
break;
}
if (0 > qs)
{
/* Special report if retries insufficient */
GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR != qs);
/* Always report on hard error as well to enable diagnostics */
GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
return TMH_RESPONSE_reply_internal_error (connection,
TALER_EC_PROPOSAL_STORE_DB_ERROR,
"db error: could not store this proposal's data into db");
}
// FIXME: now we can delete (merchant_pub, order_id) from the merchant_orders table
}
GNUNET_assert (NULL != contract_terms);
stored_nonce
= json_string_value (json_object_get (contract_terms,
"nonce"));
if (NULL == stored_nonce)
{
GNUNET_break (0);
return TMH_RESPONSE_reply_internal_error (connection,
TALER_EC_PROPOSAL_ORDER_PARSE_ERROR,
"existing proposal has no nonce");
}
if (0 != strcmp (stored_nonce,
nonce))
{
return TMH_RESPONSE_reply_bad_request (connection,
TALER_EC_PROPOSAL_LOOKUP_NOT_FOUND,
"mismatched nonce");
}
/* create proposal signature */
{
struct TALER_ProposalDataPS pdps = {
.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_CONTRACT),
.purpose.size = htonl (sizeof (pdps))
};
if (GNUNET_OK !=
TALER_JSON_hash (contract_terms,
&pdps.hash))
{
GNUNET_break (0);
return TMH_RESPONSE_reply_internal_error (connection,
TALER_EC_INTERNAL_LOGIC_ERROR,
"Could not hash order");
}
GNUNET_CRYPTO_eddsa_sign (&mi->privkey.eddsa_priv,
&pdps.purpose,
&merchant_sig);
}
res = TMH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{ s:o, s:o }",
"contract_terms",
contract_terms,
"sig",
GNUNET_JSON_from_data_auto (
&merchant_sig));
return res;
}
/* end of taler-merchant-httpd_proposal.c */