/*
This file is part of TALER
Copyright (C) 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
*/
/**
* @file mint-lib/mint_api_refresh.c
* @brief Implementation of the /refresh/melt+reveal requests of the mint's HTTP API
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include /* just for HTTP status codes */
#include
#include "taler_mint_service.h"
#include "mint_api_json.h"
#include "mint_api_context.h"
#include "mint_api_handle.h"
#include "taler_signatures.h"
/* ********************* /refresh/ common ***************************** */
/**
* Melt (partially spent) coins to obtain fresh coins that are
* unlinkable to the original coin(s). Note that melting more
* than one coin in a single request will make those coins linkable,
* so the safest operation only melts one coin at a time.
*
* This API is typically used by a wallet. Note that to ensure that
* no money is lost in case of hardware failures, is operation does
* not actually initiate the request. Instead, it generates a buffer
* which the caller must store before proceeding with the actual call
* to #TALER_MINT_refresh_execute() that will generate the request.
*
* This function does verify that the given request data is internally
* consistent. However, the @a melts_sigs are only verified if @a
* check_sigs is set to #GNUNET_YES, as this may be relatively
* expensive and should be redundant.
*
* Aside from some non-trivial cryptographic operations that might
* take a bit of CPU time to complete, this function returns
* its result immediately and does not start any asynchronous
* processing. This function is also thread-safe.
*
* @param num_melts number of coins that are being melted (typically 1)
* @param melt_privs array of @a num_melts private keys of the coins to melt
* @param melt_amounts array of @a num_melts amounts specifying how much
* each coin will contribute to the melt (including fee)
* @param melt_sigs array of @a num_melts signatures affirming the
* validity of the public keys corresponding to the
* @a melt_privs private keys
* @param melt_pks array of @a num_melts denomination key information
* records corresponding to the @a melt_sigs
* validity of the keys
* @param check_sigs verify the validity of the signatures of @a melt_sigs
* @param fresh_pks_len length of the @a pks array
* @param fresh_pks array of @a pks_len denominations of fresh coins to create
* @param[OUT] res_size set to the size of the return value, or 0 on error
* @return NULL
* if the inputs are invalid (i.e. denomination key not with this mint).
* Otherwise, pointer to a buffer of @a res_size to store persistently
* before proceeding to #TALER_MINT_refresh_execute().
* Non-null results should be freed using #GNUNET_free().
*/
char *
TALER_MINT_refresh_prepare (unsigned int num_melts,
const struct TALER_CoinSpendPrivateKeyP *melt_privs,
const struct TALER_Amount *melt_amounts,
const struct TALER_DenominationSignature *melt_sigs,
const struct TALER_MINT_DenomPublicKey *melt_pks,
int check_sigs,
unsigned int fresh_pks_len,
const struct TALER_MINT_DenomPublicKey *fresh_pks,
size_t *res_size)
{
GNUNET_break (0); // FIXME: not implemented
*res_size = 0;
return NULL;
}
/* ********************* /refresh/melt ***************************** */
/**
* @brief A /refresh/melt Handle
*/
struct TALER_MINT_RefreshMeltHandle
{
/**
* The connection to mint this request handle will use
*/
struct TALER_MINT_Handle *mint;
/**
* The url for this request.
*/
char *url;
/**
* JSON encoding of the request to POST.
*/
char *json_enc;
/**
* Handle for the request.
*/
struct MAC_Job *job;
/**
* Function to call with refresh melt failure results.
*/
TALER_MINT_RefreshMeltCallback melt_cb;
/**
* Closure for @e result_cb and @e melt_failure_cb.
*/
void *melt_cb_cls;
/**
* Download buffer
*/
struct MAC_DownloadBuffer db;
};
/**
* Function called when we're done processing the
* HTTP /refresh/melt request.
*
* @param cls the `struct TALER_MINT_RefreshMeltHandle`
* @param eh the curl request handle
*/
static void
handle_refresh_melt_finished (void *cls,
CURL *eh)
{
struct TALER_MINT_RefreshMeltHandle *rmh = cls;
long response_code;
json_t *json;
rmh->job = NULL;
json = MAC_download_get_result (&rmh->db,
eh,
&response_code);
switch (response_code)
{
case 0:
break;
case MHD_HTTP_OK:
GNUNET_break (0); // FIXME: NOT implemented! (parse, check sig!)
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_FORBIDDEN:
/* Double spending; check signatures on transaction history */
GNUNET_break (0); // FIXME: NOT implemented!
break;
case MHD_HTTP_UNAUTHORIZED:
/* Nothing really to verify, mint says one of the signatures is
invalid; assuming we checked them, this should never happen, we
should pass the 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 (NULL != rmh->melt_cb)
rmh->melt_cb (rmh->melt_cb_cls,
response_code,
UINT16_MAX,
json);
json_decref (json);
TALER_MINT_refresh_melt_cancel (rmh);
}
/**
* Submit a melt request to the mint and get the mint's
* response.
*
* This API is typically used by a wallet. Note that to ensure that
* no money is lost in case of hardware failures, the provided
* argument should have been constructed using
* #TALER_MINT_refresh_prepare and committed to persistent storage
* prior to calling this function.
*
* @param mint the mint handle; the mint must be ready to operate
* @param refresh_data_length size of the @a refresh_data (returned
* in the `res_size` argument from #TALER_MINT_refresh_prepare())
* @param refresh_data the refresh data as returned from
#TALER_MINT_refresh_prepare())
* @param melt_cb the callback to call with the result
* @param melt_cb_cls closure for @a melt_cb
* @return a handle for this request; NULL if the argument was invalid.
* In this case, neither callback will be called.
*/
struct TALER_MINT_RefreshMeltHandle *
TALER_MINT_refresh_melt (struct TALER_MINT_Handle *mint,
size_t refresh_data_length,
const char *refresh_data,
TALER_MINT_RefreshMeltCallback melt_cb,
void *melt_cb_cls)
{
json_t *melt_obj;
struct TALER_MINT_RefreshMeltHandle *rmh;
CURL *eh;
struct TALER_MINT_Context *ctx;
if (GNUNET_YES !=
MAH_handle_is_ready (mint))
{
GNUNET_break (0);
return NULL;
}
/* FIXME: parse "refresh_data" */
/* FIXME: totally bogus request building here: */
melt_obj = json_pack ("{s:o, s:O}", /* f/wire */
"4", 42,
"6", 62);
rmh = GNUNET_new (struct TALER_MINT_RefreshMeltHandle);
rmh->mint = mint;
rmh->melt_cb = melt_cb;
rmh->melt_cb_cls = melt_cb_cls;
rmh->url = MAH_path_to_url (mint,
"/refresh/melt");
eh = curl_easy_init ();
GNUNET_assert (NULL != (rmh->json_enc =
json_dumps (melt_obj,
JSON_COMPACT)));
json_decref (melt_obj);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_URL,
rmh->url));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDS,
rmh->json_enc));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDSIZE,
strlen (rmh->json_enc)));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEFUNCTION,
&MAC_download_cb));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEDATA,
&rmh->db));
ctx = MAH_handle_to_context (mint);
rmh->job = MAC_job_add (ctx,
eh,
GNUNET_YES,
&handle_refresh_melt_finished,
rmh);
return rmh;
}
/**
* Cancel a refresh execute request. This function cannot be used
* on a request handle if either callback was already invoked.
*
* @param rmh the refresh melt handle
*/
void
TALER_MINT_refresh_melt_cancel (struct TALER_MINT_RefreshMeltHandle *rmh)
{
if (NULL != rmh->job)
{
MAC_job_cancel (rmh->job);
rmh->job = NULL;
}
GNUNET_free_non_null (rmh->db.buf);
GNUNET_free (rmh->url);
GNUNET_free (rmh->json_enc);
GNUNET_free (rmh);
}
/* ********************* /refresh/reveal ***************************** */
/**
* @brief A /refresh/reveal Handle
*/
struct TALER_MINT_RefreshRevealHandle
{
/**
* The connection to mint this request handle will use
*/
struct TALER_MINT_Handle *mint;
/**
* The url for this request.
*/
char *url;
/**
* JSON encoding of the request to POST.
*/
char *json_enc;
/**
* Handle for the request.
*/
struct MAC_Job *job;
/**
* Function to call with the result.
*/
TALER_MINT_RefreshRevealCallback reveal_cb;
/**
* Closure for @e reveal_cb.
*/
void *reveal_cb_cls;
/**
* Download buffer
*/
struct MAC_DownloadBuffer db;
};
/**
* Function called when we're done processing the
* HTTP /refresh/reveal request.
*
* @param cls the `struct TALER_MINT_RefreshHandle`
* @param eh the curl request handle
*/
static void
handle_refresh_reveal_finished (void *cls,
CURL *eh)
{
struct TALER_MINT_RefreshRevealHandle *rrh = cls;
long response_code;
json_t *json;
rrh->job = NULL;
json = MAC_download_get_result (&rrh->db,
eh,
&response_code);
switch (response_code)
{
case 0:
break;
case MHD_HTTP_OK:
GNUNET_break (0); // FIXME: NOT implemented!
// rrh->reveal_cb = NULL; (call with real result, do not call again 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_CONFLICT:
/* Nothing really to verify, mint says our reveal is inconsitent
with our commitment, so either side is buggy; 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 (NULL != rrh->reveal_cb)
rrh->reveal_cb (rrh->reveal_cb_cls,
response_code,
0, NULL, NULL,
json);
json_decref (json);
TALER_MINT_refresh_reveal_cancel (rrh);
}
/**
* Submit a /refresh/reval request to the mint and get the mint's
* response.
*
* This API is typically used by a wallet. Note that to ensure that
* no money is lost in case of hardware failures, the provided
* arguments should have been committed to persistent storage
* prior to calling this function.
*
* @param mint the mint handle; the mint must be ready to operate
* @param refresh_data_length size of the @a refresh_data (returned
* in the `res_size` argument from #TALER_MINT_refresh_prepare())
* @param refresh_data the refresh data as returned from
#TALER_MINT_refresh_prepare())
* @param noreveal_index response from the mint to the
* #TALER_MINT_refresh_melt() invocation
* @param reveal_cb the callback to call with the final result of the
* refresh operation
* @param reveal_cb_cls closure for the above callback
* @return a handle for this request; NULL if the argument was invalid.
* In this case, neither callback will be called.
*/
struct TALER_MINT_RefreshRevealHandle *
TALER_MINT_refresh_reveal (struct TALER_MINT_Handle *mint,
size_t refresh_data_length,
const char *refresh_data,
uint16_t noreveal_index,
TALER_MINT_RefreshRevealCallback reveal_cb,
void *reveal_cb_cls)
{
struct TALER_MINT_RefreshRevealHandle *rrh;
json_t *reveal_obj;
CURL *eh;
struct TALER_MINT_Context *ctx;
if (GNUNET_YES !=
MAH_handle_is_ready (mint))
{
GNUNET_break (0);
return NULL;
}
/* FIXME: parse "refresh_data" */
/* FIXME: totally bogus request building here: */
reveal_obj = json_pack ("{s:o, s:O}", /* f/wire */
"4", 42,
"6", 62);
rrh = GNUNET_new (struct TALER_MINT_RefreshRevealHandle);
rrh->mint = mint;
rrh->reveal_cb = reveal_cb;
rrh->reveal_cb_cls = reveal_cb_cls;
rrh->url = MAH_path_to_url (rrh->mint,
"/refresh/reveal");
eh = curl_easy_init ();
GNUNET_assert (NULL != (rrh->json_enc =
json_dumps (reveal_obj,
JSON_COMPACT)));
json_decref (reveal_obj);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_URL,
rrh->url));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDS,
rrh->json_enc));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDSIZE,
strlen (rrh->json_enc)));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEFUNCTION,
&MAC_download_cb));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEDATA,
&rrh->db));
ctx = MAH_handle_to_context (rrh->mint);
rrh->job = MAC_job_add (ctx,
eh,
GNUNET_YES,
&handle_refresh_reveal_finished,
rrh);
return rrh;
}
/**
* Cancel a refresh reveal request. This function cannot be used
* on a request handle if the callback was already invoked.
*
* @param rrh the refresh reval handle
*/
void
TALER_MINT_refresh_reveal_cancel (struct TALER_MINT_RefreshRevealHandle *rrh)
{
if (NULL != rrh->job)
{
MAC_job_cancel (rrh->job);
rrh->job = NULL;
}
GNUNET_free_non_null (rrh->db.buf);
GNUNET_free (rrh->url);
GNUNET_free (rrh->json_enc);
GNUNET_free (rrh);
}
/* end of mint_api_refresh.c */