/*
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
*/
/**
* @file lib/exchange_api_handle.c
* @brief Implementation of the "handle" component of the exchange's HTTP API
* @author Sree Harsha Totakura
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include "taler_json_lib.h"
#include "taler_exchange_service.h"
#include "taler_auditor_service.h"
#include "taler_signatures.h"
#include "exchange_api_handle.h"
#include "exchange_api_curl_defaults.h"
#include "backoff.h"
#include "taler_curl_lib.h"
/**
* Which version of the Taler protocol is implemented
* by this library? Used to determine compatibility.
*/
#define EXCHANGE_PROTOCOL_CURRENT 9
/**
* How many versions are we backwards compatible with?
*/
#define EXCHANGE_PROTOCOL_AGE 0
/**
* Current version for (local) JSON serialization of persisted
* /keys data.
*/
#define EXCHANGE_SERIALIZATION_FORMAT_VERSION 0
/**
* Set to 1 for extra debug logging.
*/
#define DEBUG 0
/**
* Log error related to CURL operations.
*
* @param type log level
* @param function which function failed to run
* @param code what was the curl error code
*/
#define CURL_STRERROR(type, function, code) \
GNUNET_log (type, "Curl function `%s' has failed at `%s:%d' with error: %s", \
function, __FILE__, __LINE__, curl_easy_strerror (code));
/**
* Data for the request to get the /keys of a exchange.
*/
struct KeysRequest;
/**
* Entry in DLL of auditors used by an exchange.
*/
struct TEAH_AuditorListEntry
{
/**
* Next pointer of DLL.
*/
struct TEAH_AuditorListEntry *next;
/**
* Prev pointer of DLL.
*/
struct TEAH_AuditorListEntry *prev;
/**
* Base URL of the auditor.
*/
char *auditor_url;
/**
* Handle to the auditor.
*/
struct TALER_AUDITOR_Handle *ah;
/**
* Head of DLL of interactions with this auditor.
*/
struct TEAH_AuditorInteractionEntry *ai_head;
/**
* Tail of DLL of interactions with this auditor.
*/
struct TEAH_AuditorInteractionEntry *ai_tail;
/**
* Public key of the auditor.
*/
struct TALER_AuditorPublicKeyP auditor_pub;
/**
* Flag indicating that the auditor is available and that protocol
* version compatibility is given.
*/
int is_up;
};
/* ***************** Internal /keys fetching ************* */
/**
* Data for the request to get the /keys of a exchange.
*/
struct KeysRequest
{
/**
* The connection to exchange this request handle will use
*/
struct TALER_EXCHANGE_Handle *exchange;
/**
* The url for this handle
*/
char *url;
/**
* Entry for this request with the `struct GNUNET_CURL_Context`.
*/
struct GNUNET_CURL_Job *job;
/**
* Expiration time according to "Expire:" header.
* 0 if not provided by the server.
*/
struct GNUNET_TIME_Absolute expire;
};
/**
* Signature of functions called with the result from our call to the
* auditor's /deposit-confirmation handler.
*
* @param cls closure of type `struct TEAH_AuditorInteractionEntry *`
* @param hr HTTP response
*/
void
TEAH_acc_confirmation_cb (void *cls,
const struct TALER_AUDITOR_HttpResponse *hr)
{
struct TEAH_AuditorInteractionEntry *aie = cls;
struct TEAH_AuditorListEntry *ale = aie->ale;
if (MHD_HTTP_OK != hr->http_status)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to submit deposit confirmation to auditor `%s' with HTTP status %d (EC: %d). This is acceptable if it does not happen often.\n",
ale->auditor_url,
hr->http_status,
hr->ec);
}
GNUNET_CONTAINER_DLL_remove (ale->ai_head,
ale->ai_tail,
aie);
GNUNET_free (aie);
}
/**
* Iterate over all available auditors for @a h, calling
* @a ac and giving it a chance to start a deposit
* confirmation interaction.
*
* @param h exchange to go over auditors for
* @param ac function to call per auditor
* @param ac_cls closure for @a ac
*/
void
TEAH_get_auditors_for_dc (struct TALER_EXCHANGE_Handle *h,
TEAH_AuditorCallback ac,
void *ac_cls)
{
if (NULL == h->auditors_head)
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"No auditor available for exchange `%s'. Not submitting deposit confirmations.\n",
h->url);
return;
}
for (struct TEAH_AuditorListEntry *ale = h->auditors_head;
NULL != ale;
ale = ale->next)
{
struct TEAH_AuditorInteractionEntry *aie;
if (GNUNET_NO == ale->is_up)
continue;
aie = ac (ac_cls,
ale->ah,
&ale->auditor_pub);
if (NULL != aie)
{
aie->ale = ale;
GNUNET_CONTAINER_DLL_insert (ale->ai_head,
ale->ai_tail,
aie);
}
}
}
/**
* Release memory occupied by a keys request. Note that this does not
* cancel the request itself.
*
* @param kr request to free
*/
static void
free_keys_request (struct KeysRequest *kr)
{
GNUNET_free (kr->url);
GNUNET_free (kr);
}
#define EXITIF(cond) \
do { \
if (cond) { GNUNET_break (0); goto EXITIF_exit; } \
} while (0)
/**
* Parse a exchange's signing key encoded in JSON.
*
* @param[out] sign_key where to return the result
* @param check_sigs should we check signatures?
* @param[in] sign_key_obj json to parse
* @param master_key master key to use to verify signature
* @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is
* invalid or the json malformed.
*/
static enum GNUNET_GenericReturnValue
parse_json_signkey (struct TALER_EXCHANGE_SigningPublicKey *sign_key,
int check_sigs,
json_t *sign_key_obj,
const struct TALER_MasterPublicKeyP *master_key)
{
struct TALER_MasterSignatureP sign_key_issue_sig;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("master_sig",
&sign_key_issue_sig),
GNUNET_JSON_spec_fixed_auto ("key",
&sign_key->key),
TALER_JSON_spec_absolute_time ("stamp_start",
&sign_key->valid_from),
TALER_JSON_spec_absolute_time ("stamp_expire",
&sign_key->valid_until),
TALER_JSON_spec_absolute_time ("stamp_end",
&sign_key->valid_legal),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (sign_key_obj,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (! check_sigs)
return GNUNET_OK;
if (GNUNET_OK !=
TALER_exchange_offline_signkey_validity_verify (
&sign_key->key,
sign_key->valid_from,
sign_key->valid_until,
sign_key->valid_legal,
master_key,
&sign_key_issue_sig))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
sign_key->master_sig = sign_key_issue_sig;
return GNUNET_OK;
}
/**
* Parse a exchange's denomination key encoded in JSON.
*
* @param[out] denom_key where to return the result
* @param check_sigs should we check signatures?
* @param[in] denom_key_obj json to parse
* @param master_key master key to use to verify signature
* @param hash_context where to accumulate data for signature verification
* @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is
* invalid or the json malformed.
*/
static enum GNUNET_GenericReturnValue
parse_json_denomkey (struct TALER_EXCHANGE_DenomPublicKey *denom_key,
int check_sigs,
json_t *denom_key_obj,
struct TALER_MasterPublicKeyP *master_key,
struct GNUNET_HashContext *hash_context)
{
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("master_sig",
&denom_key->master_sig),
TALER_JSON_spec_absolute_time ("stamp_expire_deposit",
&denom_key->expire_deposit),
TALER_JSON_spec_absolute_time ("stamp_expire_withdraw",
&denom_key->withdraw_valid_until),
TALER_JSON_spec_absolute_time ("stamp_start",
&denom_key->valid_from),
TALER_JSON_spec_absolute_time ("stamp_expire_legal",
&denom_key->expire_legal),
TALER_JSON_spec_amount_any ("value",
&denom_key->value),
TALER_JSON_spec_amount_any ("fee_withdraw",
&denom_key->fee_withdraw),
TALER_JSON_spec_amount_any ("fee_deposit",
&denom_key->fee_deposit),
TALER_JSON_spec_amount_any ("fee_refresh",
&denom_key->fee_refresh),
TALER_JSON_spec_amount_any ("fee_refund",
&denom_key->fee_refund),
TALER_JSON_spec_denomination_public_key ("denom_pub",
&denom_key->key),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (denom_key_obj,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
TALER_denom_pub_hash (&denom_key->key,
&denom_key->h_key);
if (NULL != hash_context)
GNUNET_CRYPTO_hash_context_read (hash_context,
&denom_key->h_key,
sizeof (struct GNUNET_HashCode));
if (! check_sigs)
return GNUNET_OK;
EXITIF (GNUNET_SYSERR ==
TALER_exchange_offline_denom_validity_verify (
&denom_key->h_key,
denom_key->valid_from,
denom_key->withdraw_valid_until,
denom_key->expire_deposit,
denom_key->expire_legal,
&denom_key->value,
&denom_key->fee_withdraw,
&denom_key->fee_deposit,
&denom_key->fee_refresh,
&denom_key->fee_refund,
master_key,
&denom_key->master_sig));
return GNUNET_OK;
EXITIF_exit:
/* invalidate denom_key, just to be sure */
memset (denom_key,
0,
sizeof (*denom_key));
GNUNET_JSON_parse_free (spec);
return GNUNET_SYSERR;
}
/**
* Parse a exchange's auditor information encoded in JSON.
*
* @param[out] auditor where to return the result
* @param check_sigs should we check signatures
* @param[in] auditor_obj json to parse
* @param key_data information about denomination keys
* @return #GNUNET_OK if all is fine, #GNUNET_SYSERR if the signature is
* invalid or the json malformed.
*/
static enum GNUNET_GenericReturnValue
parse_json_auditor (struct TALER_EXCHANGE_AuditorInformation *auditor,
int check_sigs,
json_t *auditor_obj,
const struct TALER_EXCHANGE_Keys *key_data)
{
json_t *keys;
json_t *key;
unsigned int len;
unsigned int off;
unsigned int i;
const char *auditor_url;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("auditor_pub",
&auditor->auditor_pub),
GNUNET_JSON_spec_string ("auditor_url",
&auditor_url),
GNUNET_JSON_spec_json ("denomination_keys",
&keys),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (auditor_obj,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
#if DEBUG
json_dumpf (auditor_obj,
stderr,
JSON_INDENT (2));
#endif
return GNUNET_SYSERR;
}
auditor->auditor_url = GNUNET_strdup (auditor_url);
len = json_array_size (keys);
auditor->denom_keys = GNUNET_new_array (len,
struct
TALER_EXCHANGE_AuditorDenominationInfo);
off = 0;
json_array_foreach (keys, i, key) {
struct TALER_AuditorSignatureP auditor_sig;
struct TALER_DenominationHash denom_h;
const struct TALER_EXCHANGE_DenomPublicKey *dk;
unsigned int dk_off;
struct GNUNET_JSON_Specification kspec[] = {
GNUNET_JSON_spec_fixed_auto ("auditor_sig",
&auditor_sig),
GNUNET_JSON_spec_fixed_auto ("denom_pub_h",
&denom_h),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (key,
kspec,
NULL, NULL))
{
GNUNET_break_op (0);
continue;
}
dk = NULL;
dk_off = UINT_MAX;
for (unsigned int j = 0; jnum_denom_keys; j++)
{
if (0 == GNUNET_memcmp (&denom_h,
&key_data->denom_keys[j].h_key))
{
dk = &key_data->denom_keys[j];
dk_off = j;
break;
}
}
if (NULL == dk)
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Auditor signed denomination %s, which we do not know. Ignoring signature.\n",
GNUNET_h2s (&denom_h.hash));
continue;
}
if (check_sigs)
{
if (GNUNET_OK !=
TALER_auditor_denom_validity_verify (
auditor_url,
&dk->h_key,
&key_data->master_pub,
dk->valid_from,
dk->withdraw_valid_until,
dk->expire_deposit,
dk->expire_legal,
&dk->value,
&dk->fee_withdraw,
&dk->fee_deposit,
&dk->fee_refresh,
&dk->fee_refund,
&auditor->auditor_pub,
&auditor_sig))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return GNUNET_SYSERR;
}
}
auditor->denom_keys[off].denom_key_offset = dk_off;
auditor->denom_keys[off].auditor_sig = auditor_sig;
off++;
}
auditor->num_denom_keys = off;
GNUNET_JSON_parse_free (spec);
return GNUNET_OK;
}
/**
* Function called with information about the auditor. Marks an
* auditor as 'up'.
*
* @param cls closure, a `struct TEAH_AuditorListEntry *`
* @param hr http response from the auditor
* @param vi basic information about the auditor
* @param compat protocol compatibility information
*/
static void
auditor_version_cb (
void *cls,
const struct TALER_AUDITOR_HttpResponse *hr,
const struct TALER_AUDITOR_VersionInformation *vi,
enum TALER_AUDITOR_VersionCompatibility compat)
{
struct TEAH_AuditorListEntry *ale = cls;
if (NULL == vi)
{
/* In this case, we don't mark the auditor as 'up' */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Auditor `%s' gave unexpected version response.\n",
ale->auditor_url);
return;
}
if (0 != (TALER_AUDITOR_VC_INCOMPATIBLE & compat))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Auditor `%s' runs incompatible protocol version!\n",
ale->auditor_url);
if (0 != (TALER_AUDITOR_VC_OLDER & compat))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Auditor `%s' runs outdated protocol version!\n",
ale->auditor_url);
}
if (0 != (TALER_AUDITOR_VC_NEWER & compat))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Auditor `%s' runs more recent incompatible version. We should upgrade!\n",
ale->auditor_url);
}
return;
}
ale->is_up = GNUNET_YES;
}
/**
* Recalculate our auditor list, we got /keys and it may have
* changed.
*
* @param exchange exchange for which to update the list.
*/
static void
update_auditors (struct TALER_EXCHANGE_Handle *exchange)
{
struct TALER_EXCHANGE_Keys *kd = &exchange->key_data;
TALER_LOG_DEBUG ("Updating auditors\n");
for (unsigned int i = 0; inum_auditors; i++)
{
/* Compare auditor data from /keys with auditor data
* from owned exchange structures. */
struct TALER_EXCHANGE_AuditorInformation *auditor = &kd->auditors[i];
struct TEAH_AuditorListEntry *ale = NULL;
for (struct TEAH_AuditorListEntry *a = exchange->auditors_head;
NULL != a;
a = a->next)
{
if (0 == GNUNET_memcmp (&auditor->auditor_pub,
&a->auditor_pub))
{
ale = a;
break;
}
}
if (NULL != ale)
continue; /* found, no need to add */
/* new auditor, add */
TALER_LOG_DEBUG ("Found new auditor!\n");
ale = GNUNET_new (struct TEAH_AuditorListEntry);
ale->auditor_pub = auditor->auditor_pub;
ale->auditor_url = GNUNET_strdup (auditor->auditor_url);
GNUNET_CONTAINER_DLL_insert (exchange->auditors_head,
exchange->auditors_tail,
ale);
ale->ah = TALER_AUDITOR_connect (exchange->ctx,
ale->auditor_url,
&auditor_version_cb,
ale);
}
}
/**
* Compare two denomination keys. Ignores revocation data.
*
* @param denom1 first denomination key
* @param denom2 second denomination key
* @return 0 if the two keys are equal (not necessarily
* the same object), 1 otherwise.
*/
static unsigned int
denoms_cmp (const struct TALER_EXCHANGE_DenomPublicKey *denom1,
const struct TALER_EXCHANGE_DenomPublicKey *denom2)
{
struct TALER_EXCHANGE_DenomPublicKey tmp1;
struct TALER_EXCHANGE_DenomPublicKey tmp2;
if (0 !=
TALER_denom_pub_cmp (&denom1->key,
&denom2->key))
return 1;
tmp1 = *denom1;
tmp2 = *denom2;
tmp1.revoked = false;
tmp2.revoked = false;
memset (&tmp1.key,
0,
sizeof (tmp1.key));
memset (&tmp2.key,
0,
sizeof (tmp2.key));
return GNUNET_memcmp (&tmp1,
&tmp2);
}
/**
* Decode the JSON in @a resp_obj from the /keys response
* and store the data in the @a key_data.
*
* @param[in] resp_obj JSON object to parse
* @param check_sig true if we should check the signature
* @param[out] key_data where to store the results we decoded
* @param[out] vc where to store version compatibility data
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
* (malformed JSON)
*/
static enum GNUNET_GenericReturnValue
decode_keys_json (const json_t *resp_obj,
bool check_sig,
struct TALER_EXCHANGE_Keys *key_data,
enum TALER_EXCHANGE_VersionCompatibility *vc)
{
struct TALER_ExchangeSignatureP sig;
struct GNUNET_HashContext *hash_context;
struct TALER_ExchangePublicKeyP pub;
const char *currency;
struct GNUNET_JSON_Specification mspec[] = {
GNUNET_JSON_spec_fixed_auto ("eddsa_sig",
&sig),
GNUNET_JSON_spec_fixed_auto ("eddsa_pub",
&pub),
GNUNET_JSON_spec_fixed_auto ("master_public_key",
&key_data->master_pub),
TALER_JSON_spec_absolute_time ("list_issue_date",
&key_data->list_issue_date),
TALER_JSON_spec_relative_time ("reserve_closing_delay",
&key_data->reserve_closing_delay),
GNUNET_JSON_spec_string ("currency",
¤cy),
GNUNET_JSON_spec_mark_optional (
TALER_JSON_spec_amount_any ("wallet_balance_limit_without_kyc",
&key_data->wallet_balance_limit_without_kyc)),
GNUNET_JSON_spec_end ()
};
if (JSON_OBJECT != json_typeof (resp_obj))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
#if DEBUG
json_dumpf (resp_obj,
stderr,
JSON_INDENT (2));
#endif
/* check the version */
{
const char *ver;
unsigned int age;
unsigned int revision;
unsigned int current;
char dummy;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_string ("version",
&ver),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (resp_obj,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (3 != sscanf (ver,
"%u:%u:%u%c",
¤t,
&revision,
&age,
&dummy))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
*vc = TALER_EXCHANGE_VC_MATCH;
if (EXCHANGE_PROTOCOL_CURRENT < current)
{
*vc |= TALER_EXCHANGE_VC_NEWER;
if (EXCHANGE_PROTOCOL_CURRENT < current - age)
*vc |= TALER_EXCHANGE_VC_INCOMPATIBLE;
}
if (EXCHANGE_PROTOCOL_CURRENT > current)
{
*vc |= TALER_EXCHANGE_VC_OLDER;
if (EXCHANGE_PROTOCOL_CURRENT - EXCHANGE_PROTOCOL_AGE > current)
*vc |= TALER_EXCHANGE_VC_INCOMPATIBLE;
}
key_data->version = GNUNET_strdup (ver);
}
hash_context = NULL;
EXITIF (GNUNET_OK !=
GNUNET_JSON_parse (resp_obj,
(check_sig) ? mspec : &mspec[2],
NULL, NULL));
key_data->currency = GNUNET_strdup (currency);
if (GNUNET_OK ==
TALER_amount_is_valid (&key_data->wallet_balance_limit_without_kyc))
{
if (0 != strcasecmp (currency,
key_data->wallet_balance_limit_without_kyc.currency))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
}
/* parse the master public key and issue date of the response */
if (check_sig)
hash_context = GNUNET_CRYPTO_hash_context_start ();
/* parse the signing keys */
{
json_t *sign_keys_array;
json_t *sign_key_obj;
unsigned int index;
EXITIF (NULL == (sign_keys_array =
json_object_get (resp_obj,
"signkeys")));
EXITIF (JSON_ARRAY != json_typeof (sign_keys_array));
if (0 != (key_data->num_sign_keys =
json_array_size (sign_keys_array)))
{
key_data->sign_keys
= GNUNET_new_array (key_data->num_sign_keys,
struct TALER_EXCHANGE_SigningPublicKey);
json_array_foreach (sign_keys_array, index, sign_key_obj) {
EXITIF (GNUNET_SYSERR ==
parse_json_signkey (&key_data->sign_keys[index],
check_sig,
sign_key_obj,
&key_data->master_pub));
}
}
}
/* parse the denomination keys, merging with the
possibly EXISTING array as required (/keys cherry picking) */
{
json_t *denom_keys_array;
json_t *denom_key_obj;
unsigned int index;
EXITIF (NULL == (denom_keys_array =
json_object_get (resp_obj,
"denoms")));
EXITIF (JSON_ARRAY != json_typeof (denom_keys_array));
json_array_foreach (denom_keys_array, index, denom_key_obj) {
struct TALER_EXCHANGE_DenomPublicKey dk;
bool found = false;
memset (&dk,
0,
sizeof (dk));
EXITIF (GNUNET_SYSERR ==
parse_json_denomkey (&dk,
check_sig,
denom_key_obj,
&key_data->master_pub,
hash_context));
for (unsigned int j = 0;
jnum_denom_keys;
j++)
{
if (0 == denoms_cmp (&dk,
&key_data->denom_keys[j]))
{
found = true;
break;
}
}
if (found)
{
/* 0:0:0 did not support /keys cherry picking */
TALER_LOG_DEBUG ("Skipping denomination key: already know it\n");
TALER_denom_pub_free (&dk.key);
continue;
}
if (key_data->denom_keys_size == key_data->num_denom_keys)
GNUNET_array_grow (key_data->denom_keys,
key_data->denom_keys_size,
key_data->denom_keys_size * 2 + 2);
key_data->denom_keys[key_data->num_denom_keys++] = dk;
/* Update "last_denom_issue_date" */
TALER_LOG_DEBUG ("Adding denomination key that is valid_from %s\n",
GNUNET_STRINGS_absolute_time_to_string (dk.valid_from));
key_data->last_denom_issue_date
= GNUNET_TIME_absolute_max (key_data->last_denom_issue_date,
dk.valid_from);
};
}
/* parse the auditor information */
{
json_t *auditors_array;
json_t *auditor_info;
unsigned int index;
EXITIF (NULL == (auditors_array =
json_object_get (resp_obj,
"auditors")));
EXITIF (JSON_ARRAY != json_typeof (auditors_array));
/* Merge with the existing auditor information we have (/keys cherry picking) */
json_array_foreach (auditors_array, index, auditor_info) {
struct TALER_EXCHANGE_AuditorInformation ai;
bool found = false;
memset (&ai,
0,
sizeof (ai));
EXITIF (GNUNET_SYSERR ==
parse_json_auditor (&ai,
check_sig,
auditor_info,
key_data));
for (unsigned int j = 0; jnum_auditors; j++)
{
struct TALER_EXCHANGE_AuditorInformation *aix = &key_data->auditors[j];
if (0 == GNUNET_memcmp (&ai.auditor_pub,
&aix->auditor_pub))
{
found = true;
/* Merge denomination key signatures of downloaded /keys into existing
auditor information 'aix'. */
TALER_LOG_DEBUG (
"Merging %u new audited keys with %u known audited keys\n",
aix->num_denom_keys,
ai.num_denom_keys);
for (unsigned int i = 0; inum_denom_keys; k++)
{
if (aix->denom_keys[k].denom_key_offset ==
ai.denom_keys[i].denom_key_offset)
{
kfound = true;
break;
}
}
if (! kfound)
GNUNET_array_append (aix->denom_keys,
aix->num_denom_keys,
ai.denom_keys[i]);
}
break;
}
}
if (found)
{
GNUNET_array_grow (ai.denom_keys,
ai.num_denom_keys,
0);
GNUNET_free (ai.auditor_url);
continue; /* we are done */
}
if (key_data->auditors_size == key_data->num_auditors)
GNUNET_array_grow (key_data->auditors,
key_data->auditors_size,
key_data->auditors_size * 2 + 2);
GNUNET_assert (NULL != ai.auditor_url);
key_data->auditors[key_data->num_auditors++] = ai;
};
}
/* parse the revocation/recoup information */
{
json_t *recoup_array;
json_t *recoup_info;
unsigned int index;
if (NULL != (recoup_array =
json_object_get (resp_obj,
"recoup")))
{
EXITIF (JSON_ARRAY != json_typeof (recoup_array));
json_array_foreach (recoup_array, index, recoup_info) {
struct TALER_DenominationHash h_denom_pub;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("h_denom_pub",
&h_denom_pub),
GNUNET_JSON_spec_end ()
};
EXITIF (GNUNET_OK !=
GNUNET_JSON_parse (recoup_info,
spec,
NULL, NULL));
for (unsigned int j = 0;
jnum_denom_keys;
j++)
{
if (0 == GNUNET_memcmp (&h_denom_pub,
&key_data->denom_keys[j].h_key))
{
key_data->denom_keys[j].revoked = GNUNET_YES;
break;
}
}
};
}
}
if (check_sig)
{
struct TALER_ExchangeKeySetPS ks = {
.purpose.size = htonl (sizeof (ks)),
.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_KEY_SET),
.list_issue_date = GNUNET_TIME_absolute_hton (key_data->list_issue_date)
};
GNUNET_CRYPTO_hash_context_finish (hash_context,
&ks.hc);
hash_context = NULL;
EXITIF (GNUNET_OK !=
TALER_EXCHANGE_test_signing_key (key_data,
&pub));
EXITIF (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_KEY_SET,
&ks,
&sig.eddsa_signature,
&pub.eddsa_pub));
}
return GNUNET_OK;
EXITIF_exit:
*vc = TALER_EXCHANGE_VC_PROTOCOL_ERROR;
if (NULL != hash_context)
GNUNET_CRYPTO_hash_context_abort (hash_context);
return GNUNET_SYSERR;
}
/**
* Free key data object.
*
* @param key_data data to free (pointer itself excluded)
*/
static void
free_key_data (struct TALER_EXCHANGE_Keys *key_data)
{
GNUNET_array_grow (key_data->sign_keys,
key_data->num_sign_keys,
0);
for (unsigned int i = 0; inum_denom_keys; i++)
TALER_denom_pub_free (&key_data->denom_keys[i].key);
GNUNET_array_grow (key_data->denom_keys,
key_data->denom_keys_size,
0);
for (unsigned int i = 0; inum_auditors; i++)
{
GNUNET_array_grow (key_data->auditors[i].denom_keys,
key_data->auditors[i].num_denom_keys,
0);
GNUNET_free (key_data->auditors[i].auditor_url);
}
GNUNET_array_grow (key_data->auditors,
key_data->auditors_size,
0);
GNUNET_free (key_data->version);
key_data->version = NULL;
GNUNET_free (key_data->currency);
key_data->currency = NULL;
}
/**
* Initiate download of /keys from the exchange.
*
* @param cls exchange where to download /keys from
*/
static void
request_keys (void *cls);
/**
* Let the user set the last valid denomination time manually.
*
* @param exchange the exchange handle.
* @param last_denom_new new last denomination time.
*/
void
TALER_EXCHANGE_set_last_denom (struct TALER_EXCHANGE_Handle *exchange,
struct GNUNET_TIME_Absolute last_denom_new)
{
exchange->key_data.last_denom_issue_date = last_denom_new;
}
/**
* Check if our current response for /keys is valid, and if
* not trigger download.
*
* @param exchange exchange to check keys for
* @param flags options controlling when to download what
* @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,
enum TALER_EXCHANGE_CheckKeysFlags flags)
{
bool force_download = 0 != (flags & TALER_EXCHANGE_CKF_FORCE_DOWNLOAD);
bool pull_all_keys = 0 != (flags & TALER_EXCHANGE_CKF_PULL_ALL_KEYS);
if (NULL != exchange->kr)
return GNUNET_TIME_UNIT_ZERO_ABS;
if (pull_all_keys)
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Forcing re-download of all exchange keys\n");
GNUNET_break (GNUNET_YES == force_download);
exchange->state = MHS_INIT;
}
if ( (! force_download) &&
(GNUNET_TIME_absolute_is_future (exchange->key_data_expiration)) )
return exchange->key_data_expiration;
if (NULL == exchange->retry_task)
exchange->retry_task = GNUNET_SCHEDULER_add_now (&request_keys,
exchange);
return GNUNET_TIME_UNIT_ZERO_ABS;
}
/**
* Callback used when downloading the reply to a /keys request
* is complete.
*
* @param cls the `struct KeysRequest`
* @param response_code HTTP response code, 0 on error
* @param resp_obj parsed JSON result, NULL on error
*/
static void
keys_completed_cb (void *cls,
long response_code,
const void *resp_obj)
{
struct KeysRequest *kr = cls;
struct TALER_EXCHANGE_Handle *exchange = kr->exchange;
struct TALER_EXCHANGE_Keys kd;
struct TALER_EXCHANGE_Keys kd_old;
enum TALER_EXCHANGE_VersionCompatibility vc;
const json_t *j = resp_obj;
struct TALER_EXCHANGE_HttpResponse hr = {
.reply = j,
.http_status = (unsigned int) response_code
};
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Received keys from URL `%s' with status %ld.\n",
kr->url,
response_code);
kd_old = exchange->key_data;
memset (&kd,
0,
sizeof (struct TALER_EXCHANGE_Keys));
vc = TALER_EXCHANGE_VC_PROTOCOL_ERROR;
switch (response_code)
{
case 0:
free_keys_request (kr);
exchange->keys_error_count++;
exchange->kr = NULL;
GNUNET_assert (NULL == exchange->retry_task);
exchange->retry_delay = EXCHANGE_LIB_BACKOFF (exchange->retry_delay);
exchange->retry_task = GNUNET_SCHEDULER_add_delayed (exchange->retry_delay,
&request_keys,
exchange);
return;
case MHD_HTTP_OK:
exchange->keys_error_count = 0;
if (NULL == j)
{
response_code = 0;
break;
}
/* We keep the denomination keys and auditor signatures from the
previous iteration (/keys cherry picking) */
kd.num_denom_keys = kd_old.num_denom_keys;
kd.last_denom_issue_date = kd_old.last_denom_issue_date;
GNUNET_array_grow (kd.denom_keys,
kd.denom_keys_size,
kd.num_denom_keys);
/* First make a shallow copy, we then need another pass for the RSA key... */
memcpy (kd.denom_keys,
kd_old.denom_keys,
kd_old.num_denom_keys * sizeof (struct
TALER_EXCHANGE_DenomPublicKey));
for (unsigned int i = 0; iauditor_pub = aold->auditor_pub;
GNUNET_assert (NULL != aold->auditor_url);
anew->auditor_url = GNUNET_strdup (aold->auditor_url);
GNUNET_array_grow (anew->denom_keys,
anew->num_denom_keys,
aold->num_denom_keys);
memcpy (anew->denom_keys,
aold->denom_keys,
aold->num_denom_keys
* sizeof (struct TALER_EXCHANGE_AuditorDenominationInfo));
}
/* Old auditors got just copied into new ones. */
if (GNUNET_OK !=
decode_keys_json (j,
true,
&kd,
&vc))
{
TALER_LOG_ERROR ("Could not decode /keys response\n");
hr.http_status = 0;
hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
for (unsigned int i = 0; idenom_keys,
anew->num_denom_keys,
0);
GNUNET_free (anew->auditor_url);
}
GNUNET_free (kd.auditors);
kd.auditors = NULL;
kd.num_auditors = 0;
for (unsigned int i = 0; ikey_data_raw);
exchange->key_data_raw = json_deep_copy (j);
exchange->retry_delay = GNUNET_TIME_UNIT_ZERO;
break;
case MHD_HTTP_BAD_REQUEST:
case MHD_HTTP_UNAUTHORIZED:
case MHD_HTTP_FORBIDDEN:
case MHD_HTTP_NOT_FOUND:
if (NULL == j)
{
hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
hr.hint = TALER_ErrorCode_get_hint (hr.ec);
}
else
{
hr.ec = TALER_JSON_get_error_code (j);
hr.hint = TALER_JSON_get_error_hint (j);
}
break;
default:
if (MHD_HTTP_GATEWAY_TIMEOUT == response_code)
exchange->keys_error_count++;
if (NULL == j)
{
hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
hr.hint = TALER_ErrorCode_get_hint (hr.ec);
}
else
{
hr.ec = TALER_JSON_get_error_code (j);
hr.hint = TALER_JSON_get_error_hint (j);
}
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u/%d\n",
(unsigned int) response_code,
(int) hr.ec);
break;
}
exchange->key_data = kd;
TALER_LOG_DEBUG ("Last DK issue date update to: %s\n",
GNUNET_STRINGS_absolute_time_to_string
(exchange->key_data.last_denom_issue_date));
if (MHD_HTTP_OK != response_code)
{
exchange->kr = NULL;
free_keys_request (kr);
exchange->state = MHS_FAILED;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Exchange keys download failed\n");
if (NULL != exchange->key_data_raw)
{
json_decref (exchange->key_data_raw);
exchange->key_data_raw = NULL;
}
free_key_data (&kd_old);
/* notify application that we failed */
exchange->cert_cb (exchange->cert_cb_cls,
&hr,
NULL,
vc);
return;
}
exchange->kr = NULL;
exchange->key_data_expiration = kr->expire;
free_keys_request (kr);
exchange->state = MHS_CERT;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Successfully downloaded exchange's keys\n");
update_auditors (exchange);
/* notify application about the key information */
exchange->cert_cb (exchange->cert_cb_cls,
&hr,
&exchange->key_data,
vc);
free_key_data (&kd_old);
}
/* ********************* library internal API ********* */
/**
* Get the context of a exchange.
*
* @param h the exchange handle to query
* @return ctx context to execute jobs in
*/
struct GNUNET_CURL_Context *
TEAH_handle_to_context (struct TALER_EXCHANGE_Handle *h)
{
return h->ctx;
}
/**
* Check if the handle is ready to process requests.
*
* @param h the exchange handle to query
* @return #GNUNET_YES if we are ready, #GNUNET_NO if not
*/
enum GNUNET_GenericReturnValue
TEAH_handle_is_ready (struct TALER_EXCHANGE_Handle *h)
{
return (MHS_CERT == h->state) ? GNUNET_YES : GNUNET_NO;
}
/**
* Obtain the URL to use for an API request.
*
* @param h handle for the exchange
* @param path Taler API path (i.e. "/reserve/withdraw")
* @return the full URL to use with cURL
*/
char *
TEAH_path_to_url (struct TALER_EXCHANGE_Handle *h,
const char *path)
{
GNUNET_assert ('/' == path[0]);
return TALER_url_join (h->url,
path + 1,
NULL);
}
/**
* Define a max length for the HTTP "Expire:" header
*/
#define MAX_DATE_LINE_LEN 32
/**
* Parse HTTP timestamp.
*
* @param dateline header to parse header
* @param at where to write the result
* @return #GNUNET_OK on success
*/
static enum GNUNET_GenericReturnValue
parse_date_string (const char *dateline,
struct GNUNET_TIME_Absolute *at)
{
static const char *MONTHS[] =
{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec", NULL };
int year;
int mon;
int day;
int hour;
int min;
int sec;
char month[4];
struct tm tm;
time_t t;
/* We recognize the three formats in RFC2616, section 3.3.1. Month
names are always in English. The formats are:
Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
Note that the first is preferred.
*/
if (strlen (dateline) > MAX_DATE_LINE_LEN)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
while (*dateline == ' ')
++dateline;
while (*dateline && *dateline != ' ')
++dateline;
while (*dateline == ' ')
++dateline;
/* We just skipped over the day of the week. Now we have:*/
if ( (sscanf (dateline,
"%d %3s %d %d:%d:%d",
&day, month, &year, &hour, &min, &sec) != 6) &&
(sscanf (dateline,
"%d-%3s-%d %d:%d:%d",
&day, month, &year, &hour, &min, &sec) != 6) &&
(sscanf (dateline,
"%3s %d %d:%d:%d %d",
month, &day, &hour, &min, &sec, &year) != 6) )
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
/* Two digit dates are defined to be relative to 1900; all other dates
* are supposed to be represented as four digits. */
if (year < 100)
year += 1900;
for (mon = 0; ; mon++)
{
if (! MONTHS[mon])
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (0 == strcasecmp (month,
MONTHS[mon]))
break;
}
memset (&tm, 0, sizeof(tm));
tm.tm_year = year - 1900;
tm.tm_mon = mon;
tm.tm_mday = day;
tm.tm_hour = hour;
tm.tm_min = min;
tm.tm_sec = sec;
t = mktime (&tm);
if (((time_t) -1) == t)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
"mktime");
return GNUNET_SYSERR;
}
if (t < 0)
t = 0; /* can happen due to timezone issues if date was 1.1.1970 */
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 of 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);
kr->expire = GNUNET_TIME_UNIT_ZERO_ABS;
}
GNUNET_free (val);
return total;
}
/* ********************* public API ******************* */
/**
* Deserialize the key data and use it to bootstrap @a exchange to
* more efficiently recover the state. Errors in @a data must be
* tolerated (i.e. by re-downloading instead).
*
* @param exchange which exchange's key and wire data should be deserialized
* @param data the data to deserialize
*/
static void
deserialize_data (struct TALER_EXCHANGE_Handle *exchange,
const json_t *data)
{
enum TALER_EXCHANGE_VersionCompatibility vc;
json_t *keys;
const char *url;
uint32_t version;
struct GNUNET_TIME_Absolute expire;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_uint32 ("version",
&version),
GNUNET_JSON_spec_json ("keys",
&keys),
GNUNET_JSON_spec_string ("exchange_url",
&url),
TALER_JSON_spec_absolute_time ("expire",
&expire),
GNUNET_JSON_spec_end ()
};
struct TALER_EXCHANGE_Keys key_data;
struct TALER_EXCHANGE_HttpResponse hr = {
.ec = TALER_EC_NONE,
.http_status = MHD_HTTP_OK,
.reply = data
};
if (NULL == data)
return;
if (GNUNET_OK !=
GNUNET_JSON_parse (data,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return;
}
if (0 != version)
{
GNUNET_JSON_parse_free (spec);
return; /* unsupported version */
}
if (0 != strcmp (url,
exchange->url))
{
GNUNET_break (0);
GNUNET_JSON_parse_free (spec);
return;
}
memset (&key_data,
0,
sizeof (struct TALER_EXCHANGE_Keys));
if (GNUNET_OK !=
decode_keys_json (keys,
false,
&key_data,
&vc))
{
GNUNET_break (0);
GNUNET_JSON_parse_free (spec);
return;
}
/* decode successful, initialize with the result */
GNUNET_assert (NULL == exchange->key_data_raw);
exchange->key_data_raw = json_deep_copy (keys);
exchange->key_data = key_data;
exchange->key_data_expiration = expire;
exchange->state = MHS_CERT;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Successfully loaded exchange's keys via deserialization\n");
update_auditors (exchange);
/* notify application about the key information */
exchange->cert_cb (exchange->cert_cb_cls,
&hr,
&exchange->key_data,
vc);
GNUNET_JSON_parse_free (spec);
}
/**
* Serialize the latest key data from @a
* exchange to be persisted on disk (to be used with
* #TALER_EXCHANGE_OPTION_DATA to more efficiently recover
* the state).
*
* @param exchange which exchange's key and wire data should be
* serialized
* @return NULL on error (i.e. no current data available);
* otherwise JSON object owned by the caller
*/
json_t *
TALER_EXCHANGE_serialize_data (struct TALER_EXCHANGE_Handle *exchange)
{
const struct TALER_EXCHANGE_Keys *kd = &exchange->key_data;
struct GNUNET_TIME_Absolute now;
json_t *keys;
json_t *signkeys;
json_t *denoms;
json_t *auditors;
now = GNUNET_TIME_absolute_get ();
signkeys = json_array ();
if (NULL == signkeys)
{
GNUNET_break (0);
return NULL;
}
for (unsigned int i = 0; inum_sign_keys; i++)
{
const struct TALER_EXCHANGE_SigningPublicKey *sk = &kd->sign_keys[i];
json_t *signkey;
if (now.abs_value_us > sk->valid_until.abs_value_us)
continue; /* skip keys that have expired */
signkey = GNUNET_JSON_PACK (
GNUNET_JSON_pack_data_auto ("key",
&sk->key),
GNUNET_JSON_pack_data_auto ("master_sig",
&sk->master_sig),
GNUNET_JSON_pack_time_abs ("stamp_start",
sk->valid_from),
GNUNET_JSON_pack_time_abs ("stamp_expire",
sk->valid_until),
GNUNET_JSON_pack_time_abs ("stamp_end",
sk->valid_legal));
if (NULL == signkey)
{
GNUNET_break (0);
continue;
}
if (0 != json_array_append_new (signkeys,
signkey))
{
GNUNET_break (0);
json_decref (signkey);
json_decref (signkeys);
return NULL;
}
}
denoms = json_array ();
if (NULL == denoms)
{
GNUNET_break (0);
json_decref (signkeys);
return NULL;
}
for (unsigned int i = 0; inum_denom_keys; i++)
{
const struct TALER_EXCHANGE_DenomPublicKey *dk = &kd->denom_keys[i];
json_t *denom;
if (now.abs_value_us > dk->expire_deposit.abs_value_us)
continue; /* skip keys that have expired */
denom = GNUNET_JSON_PACK (
GNUNET_JSON_pack_time_abs ("stamp_expire_deposit",
dk->expire_deposit),
GNUNET_JSON_pack_time_abs ("stamp_expire_withdraw",
dk->withdraw_valid_until),
GNUNET_JSON_pack_time_abs ("stamp_start",
dk->valid_from),
GNUNET_JSON_pack_time_abs ("stamp_expire_legal",
dk->expire_legal),
TALER_JSON_pack_amount ("value",
&dk->value),
TALER_JSON_pack_amount ("fee_withdraw",
&dk->fee_withdraw),
TALER_JSON_pack_amount ("fee_deposit",
&dk->fee_deposit),
TALER_JSON_pack_amount ("fee_refresh",
&dk->fee_refresh),
TALER_JSON_pack_amount ("fee_refund",
&dk->fee_refund),
GNUNET_JSON_pack_data_auto ("master_sig",
&dk->master_sig),
TALER_JSON_pack_denomination_public_key ("denom_pub",
&dk->key));
GNUNET_assert (0 ==
json_array_append_new (denoms,
denom));
}
auditors = json_array ();
GNUNET_assert (NULL != auditors);
for (unsigned int i = 0; inum_auditors; i++)
{
const struct TALER_EXCHANGE_AuditorInformation *ai = &kd->auditors[i];
json_t *a;
json_t *adenoms;
adenoms = json_array ();
if (NULL == adenoms)
{
GNUNET_break (0);
json_decref (denoms);
json_decref (signkeys);
json_decref (auditors);
return NULL;
}
for (unsigned int j = 0; jnum_denom_keys; j++)
{
const struct TALER_EXCHANGE_AuditorDenominationInfo *adi =
&ai->denom_keys[j];
const struct TALER_EXCHANGE_DenomPublicKey *dk =
&kd->denom_keys[adi->denom_key_offset];
json_t *k;
if (now.abs_value_us > dk->expire_deposit.abs_value_us)
continue; /* skip auditor signatures for denomination keys that have expired */
GNUNET_assert (adi->denom_key_offset < kd->num_denom_keys);
k = GNUNET_JSON_PACK (
GNUNET_JSON_pack_data_auto ("denom_pub_h",
&dk->h_key),
GNUNET_JSON_pack_data_auto ("auditor_sig",
&adi->auditor_sig));
GNUNET_assert (0 ==
json_array_append_new (adenoms,
k));
}
a = GNUNET_JSON_PACK (
GNUNET_JSON_pack_data_auto ("auditor_pub",
&ai->auditor_pub),
GNUNET_JSON_pack_string ("auditor_url",
ai->auditor_url),
GNUNET_JSON_pack_array_steal ("denomination_keys",
adenoms));
GNUNET_assert (0 ==
json_array_append_new (auditors,
a));
}
keys = GNUNET_JSON_PACK (
GNUNET_JSON_pack_string ("version",
kd->version),
GNUNET_JSON_pack_string ("currency",
kd->currency),
GNUNET_JSON_pack_data_auto ("master_public_key",
&kd->master_pub),
GNUNET_JSON_pack_time_rel ("reserve_closing_delay",
kd->reserve_closing_delay),
GNUNET_JSON_pack_time_abs ("list_issue_date",
kd->list_issue_date),
GNUNET_JSON_pack_array_steal ("signkeys",
signkeys),
GNUNET_JSON_pack_array_steal ("denoms",
denoms),
GNUNET_JSON_pack_array_steal ("auditors",
auditors));
return GNUNET_JSON_PACK (
GNUNET_JSON_pack_uint64 ("version",
EXCHANGE_SERIALIZATION_FORMAT_VERSION),
GNUNET_JSON_pack_time_abs ("expire",
exchange->key_data_expiration),
GNUNET_JSON_pack_string ("exchange_url",
exchange->url),
GNUNET_JSON_pack_object_steal ("keys",
keys));
}
/**
* Initialise a connection to the exchange. Will connect to the
* exchange and obtain information about the exchange's master
* public key and the exchange's auditor.
* The respective information will be passed to the @a cert_cb
* once available, and all future interactions with the exchange
* will be checked to be signed (where appropriate) by the
* respective master key.
*
* @param ctx the context
* @param url HTTP base URL for the exchange
* @param cert_cb function to call with the exchange's
* certification information
* @param cert_cb_cls closure for @a cert_cb
* @param ... list of additional arguments,
* terminated by #TALER_EXCHANGE_OPTION_END.
* @return the exchange handle; NULL upon error
*/
struct TALER_EXCHANGE_Handle *
TALER_EXCHANGE_connect (
struct GNUNET_CURL_Context *ctx,
const char *url,
TALER_EXCHANGE_CertificationCallback cert_cb,
void *cert_cb_cls,
...)
{
struct TALER_EXCHANGE_Handle *exchange;
va_list ap;
enum TALER_EXCHANGE_Option opt;
TALER_LOG_DEBUG ("Connecting to the exchange (%s)\n",
url);
/* Disable 100 continue processing */
GNUNET_break (GNUNET_OK ==
GNUNET_CURL_append_header (ctx,
"Expect:"));
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;
exchange->retry_task = GNUNET_SCHEDULER_add_now (&request_keys,
exchange);
va_start (ap, cert_cb_cls);
while (TALER_EXCHANGE_OPTION_END !=
(opt = va_arg (ap, int)))
{
switch (opt)
{
case TALER_EXCHANGE_OPTION_END:
GNUNET_assert (0);
break;
case TALER_EXCHANGE_OPTION_DATA:
{
const json_t *data = va_arg (ap, const json_t *);
deserialize_data (exchange,
data);
break;
}
default:
GNUNET_assert (0);
break;
}
}
va_end (ap);
return exchange;
}
/**
* Compute the network timeout for the next request to /keys.
*
* @param exchange the exchange handle
* @returns the timeout in seconds (for use by CURL)
*/
static long
get_keys_timeout_seconds (struct TALER_EXCHANGE_Handle *exchange)
{
unsigned int kec;
/* if retry counter >= 8, do not bother to go further, we
stop the exponential back-off at 128 anyway. */
kec = GNUNET_MIN (7,
exchange->keys_error_count);
return GNUNET_MIN (120,
5 + (1L << kec));
}
/**
* Initiate download of /keys from the exchange.
*
* @param cls exchange where to download /keys from
*/
static void
request_keys (void *cls)
{
struct TALER_EXCHANGE_Handle *exchange = cls;
struct KeysRequest *kr;
CURL *eh;
char url[200] = "/keys?";
exchange->retry_task = NULL;
GNUNET_assert (NULL == exchange->kr);
kr = GNUNET_new (struct KeysRequest);
kr->exchange = exchange;
if (GNUNET_YES == TEAH_handle_is_ready (exchange))
{
TALER_LOG_DEBUG ("Last DK issue date (before GETting /keys): %s\n",
GNUNET_STRINGS_absolute_time_to_string (
exchange->key_data.last_denom_issue_date));
sprintf (&url[strlen (url)],
"last_issue_date=%llu&",
(unsigned long
long) exchange->key_data.last_denom_issue_date.abs_value_us
/ 1000000LLU);
}
/* Clean the last '&'/'?' sign that we optimistically put. */
url[strlen (url) - 1] = '\0';
kr->url = TEAH_path_to_url (exchange,
url);
if (NULL == kr->url)
{
struct TALER_EXCHANGE_HttpResponse hr = {
.ec = TALER_EC_GENERIC_CONFIGURATION_INVALID
};
GNUNET_free (kr);
exchange->keys_error_count++;
exchange->state = MHS_FAILED;
exchange->cert_cb (exchange->cert_cb_cls,
&hr,
NULL,
TALER_EXCHANGE_VC_PROTOCOL_ERROR);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Requesting keys with URL `%s'.\n",
kr->url);
eh = TALER_EXCHANGE_curl_easy_get_ (kr->url);
if (NULL == eh)
{
GNUNET_free (kr->url);
GNUNET_free (kr);
exchange->retry_delay = EXCHANGE_LIB_BACKOFF (exchange->retry_delay);
exchange->retry_task = GNUNET_SCHEDULER_add_delayed (exchange->retry_delay,
&request_keys,
exchange);
return;
}
GNUNET_break (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_VERBOSE,
0));
GNUNET_break (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_TIMEOUT,
get_keys_timeout_seconds (exchange)));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_HEADERFUNCTION,
&header_cb));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_HEADERDATA,
kr));
kr->job = GNUNET_CURL_job_add_with_ct_json (exchange->ctx,
eh,
&keys_completed_cb,
kr);
exchange->kr = kr;
}
/**
* Disconnect from the exchange
*
* @param exchange the exchange handle
*/
void
TALER_EXCHANGE_disconnect (struct TALER_EXCHANGE_Handle *exchange)
{
struct TEAH_AuditorListEntry *ale;
while (NULL != (ale = exchange->auditors_head))
{
struct TEAH_AuditorInteractionEntry *aie;
while (NULL != (aie = ale->ai_head))
{
GNUNET_assert (aie->ale == ale);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Not sending deposit confirmation to auditor `%s' due to exchange disconnect\n",
ale->auditor_url);
TALER_AUDITOR_deposit_confirmation_cancel (aie->dch);
GNUNET_CONTAINER_DLL_remove (ale->ai_head,
ale->ai_tail,
aie);
GNUNET_free (aie);
}
GNUNET_CONTAINER_DLL_remove (exchange->auditors_head,
exchange->auditors_tail,
ale);
TALER_LOG_DEBUG ("Disconnecting the auditor `%s'\n",
ale->auditor_url);
TALER_AUDITOR_disconnect (ale->ah);
GNUNET_free (ale->auditor_url);
GNUNET_free (ale);
}
if (NULL != exchange->kr)
{
GNUNET_CURL_job_cancel (exchange->kr->job);
free_keys_request (exchange->kr);
exchange->kr = NULL;
}
free_key_data (&exchange->key_data);
if (NULL != exchange->key_data_raw)
{
json_decref (exchange->key_data_raw);
exchange->key_data_raw = NULL;
}
if (NULL != exchange->retry_task)
{
GNUNET_SCHEDULER_cancel (exchange->retry_task);
exchange->retry_task = NULL;
}
GNUNET_free (exchange->url);
GNUNET_free (exchange);
}
/**
* Test if the given @a pub is a the current signing key from the exchange
* according to @a keys.
*
* @param keys the exchange's key set
* @param pub claimed current online signing key for the exchange
* @return #GNUNET_OK if @a pub is (according to /keys) a current signing key
*/
enum GNUNET_GenericReturnValue
TALER_EXCHANGE_test_signing_key (const struct TALER_EXCHANGE_Keys *keys,
const struct TALER_ExchangePublicKeyP *pub)
{
struct GNUNET_TIME_Absolute now;
/* we will check using a tolerance of 1h for the time */
now = GNUNET_TIME_absolute_get ();
for (unsigned int i = 0; inum_sign_keys; i++)
if ( (keys->sign_keys[i].valid_from.abs_value_us <= now.abs_value_us + 60
* 60 * 1000LL * 1000LL) &&
(keys->sign_keys[i].valid_until.abs_value_us > now.abs_value_us - 60
* 60 * 1000LL * 1000LL) &&
(0 == GNUNET_memcmp (pub,
&keys->sign_keys[i].key)) )
return GNUNET_OK;
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Signing key not valid at time %llu\n",
(unsigned long long) now.abs_value_us);
return GNUNET_SYSERR;
}
/**
* Get exchange's base URL.
*
* @param exchange exchange handle.
* @return the base URL from the handle.
*/
const char *
TALER_EXCHANGE_get_base_url (const struct TALER_EXCHANGE_Handle *exchange)
{
return exchange->url;
}
/**
* Obtain the denomination key details from the exchange.
*
* @param keys the exchange's key set
* @param pk public key of the denomination to lookup
* @return details about the given denomination key, NULL if the key is
* not found
*/
const struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_get_denomination_key (
const struct TALER_EXCHANGE_Keys *keys,
const struct TALER_DenominationPublicKey *pk)
{
for (unsigned int i = 0; inum_denom_keys; i++)
if (0 ==
TALER_denom_pub_cmp (pk,
&keys->denom_keys[i].key))
return &keys->denom_keys[i];
return NULL;
}
/**
* Create a copy of a denomination public key.
*
* @param key key to copy
* @returns a copy, must be freed with #TALER_EXCHANGE_destroy_denomination_key
*/
struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_copy_denomination_key (
const struct TALER_EXCHANGE_DenomPublicKey *key)
{
struct TALER_EXCHANGE_DenomPublicKey *copy;
copy = GNUNET_new (struct TALER_EXCHANGE_DenomPublicKey);
*copy = *key;
TALER_denom_pub_deep_copy (©->key,
&key->key);
return copy;
}
/**
* Destroy a denomination public key.
* Should only be called with keys created by #TALER_EXCHANGE_copy_denomination_key.
*
* @param key key to destroy.
*/
void
TALER_EXCHANGE_destroy_denomination_key (
struct TALER_EXCHANGE_DenomPublicKey *key)
{
TALER_denom_pub_free (&key->key);
GNUNET_free (key);
}
/**
* Obtain the denomination key details from the exchange.
*
* @param keys the exchange's key set
* @param hc hash of the public key of the denomination to lookup
* @return details about the given denomination key
*/
const struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_get_denomination_key_by_hash (
const struct TALER_EXCHANGE_Keys *keys,
const struct TALER_DenominationHash *hc)
{
for (unsigned int i = 0; inum_denom_keys; i++)
if (0 == GNUNET_memcmp (hc,
&keys->denom_keys[i].h_key))
return &keys->denom_keys[i];
return NULL;
}
/**
* Obtain the keys from the exchange.
*
* @param exchange the exchange handle
* @return the exchange's key set
*/
const struct TALER_EXCHANGE_Keys *
TALER_EXCHANGE_get_keys (struct TALER_EXCHANGE_Handle *exchange)
{
(void) TALER_EXCHANGE_check_keys_current (exchange,
TALER_EXCHANGE_CKF_NONE);
return &exchange->key_data;
}
/**
* Obtain the keys from the exchange in the
* raw JSON format
*
* @param exchange the exchange handle
* @return the exchange's keys in raw JSON
*/
json_t *
TALER_EXCHANGE_get_keys_raw (struct TALER_EXCHANGE_Handle *exchange)
{
(void) TALER_EXCHANGE_check_keys_current (exchange,
TALER_EXCHANGE_CKF_NONE);
return json_deep_copy (exchange->key_data_raw);
}
/* end of exchange_api_handle.c */