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exchange/src/lib/exchange_api_handle.c
Christian Grothoff cdc8c5b57b
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2020-02-29 16:54:58 +01:00

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/*
This file is part of TALER
Copyright (C) 2014-2018 Taler Systems SA
TALER is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3, or (at your
option) any later version.
TALER is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public
License along with TALER; see the file COPYING. If not, see
<http://www.gnu.org/licenses/>
*/
/**
* @file lib/exchange_api_handle.c
* @brief Implementation of the "handle" component of the exchange's HTTP API
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
* @author Christian Grothoff
*/
#include "platform.h"
#include <microhttpd.h>
#include <gnunet/gnunet_curl_lib.h>
#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 revision of the Taler protocol is implemented
* by this library? Used to determine compatibility.
*/
#define TALER_PROTOCOL_CURRENT 6
/**
* How many revisions back are we compatible to?
*/
#define TALER_PROTOCOL_AGE 0
/**
* Current version for (local) JSON serialization of persisted
* /keys data.
*/
#define TALER_SERIALIZATION_FORMAT_VERSION 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));
/**
* Stages of initialization for the `struct TALER_EXCHANGE_Handle`
*/
enum ExchangeHandleState
{
/**
* Just allocated.
*/
MHS_INIT = 0,
/**
* Obtained the exchange's certification data and keys.
*/
MHS_CERT = 1,
/**
* Failed to initialize (fatal).
*/
MHS_FAILED = 2
};
/**
* 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;
};
/**
* Handle to the exchange
*/
struct TALER_EXCHANGE_Handle
{
/**
* The context of this handle
*/
struct GNUNET_CURL_Context *ctx;
/**
* The URL of the exchange (i.e. "http://exchange.taler.net/")
*/
char *url;
/**
* Function to call with the exchange's certification data,
* NULL if this has already been done.
*/
TALER_EXCHANGE_CertificationCallback cert_cb;
/**
* Closure to pass to @e cert_cb.
*/
void *cert_cb_cls;
/**
* Data for the request to get the /keys of a exchange,
* NULL once we are past stage #MHS_INIT.
*/
struct KeysRequest *kr;
/**
* Task for retrying /keys request.
*/
struct GNUNET_SCHEDULER_Task *retry_task;
/**
* Raw key data of the exchange, only valid if
* @e handshake_complete is past stage #MHS_CERT.
*/
json_t *key_data_raw;
/**
* Head of DLL of auditors of this exchange.
*/
struct TEAH_AuditorListEntry *auditors_head;
/**
* Tail of DLL of auditors of this exchange.
*/
struct TEAH_AuditorListEntry *auditors_tail;
/**
* Key data of the exchange, only valid if
* @e handshake_complete is past stage #MHS_CERT.
*/
struct TALER_EXCHANGE_Keys key_data;
/**
* Retry /keys frequency.
*/
struct GNUNET_TIME_Relative retry_delay;
/**
* When does @e key_data expire?
*/
struct GNUNET_TIME_Absolute key_data_expiration;
/**
* Stage of the exchange's initialization routines.
*/
enum ExchangeHandleState state;
/**
* If GNUNET_YES, use fake now given by the user, in
* request of "/keys".
*/
int with_now;
/**
* Fake now given by the user.
*/
struct GNUNET_TIME_Absolute now;
};
/* ***************** 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 http_status HTTP status code, 200 on success
* @param ec taler protocol error status code, 0 on success
* @param json raw json response
*/
void
TEAH_acc_confirmation_cb (void *cls,
unsigned int http_status,
enum TALER_ErrorCode ec,
const json_t *json)
{
struct TEAH_AuditorInteractionEntry *aie = cls;
struct TEAH_AuditorListEntry *ale = aie->ale;
(void) json;
if (MHD_HTTP_OK != 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,
http_status,
(int) 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 int
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_ExchangeSigningKeyValidityPS sign_key_issue;
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),
GNUNET_JSON_spec_absolute_time ("stamp_start",
&sign_key->valid_from),
GNUNET_JSON_spec_absolute_time ("stamp_expire",
&sign_key->valid_until),
GNUNET_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;
sign_key_issue.signkey_pub = sign_key->key;
sign_key_issue.purpose.purpose = htonl (
TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY);
sign_key_issue.purpose.size = htonl (sizeof (struct
TALER_ExchangeSigningKeyValidityPS));
sign_key_issue.master_public_key = *master_key;
sign_key_issue.start = GNUNET_TIME_absolute_hton (sign_key->valid_from);
sign_key_issue.expire = GNUNET_TIME_absolute_hton (sign_key->valid_until);
sign_key_issue.end = GNUNET_TIME_absolute_hton (sign_key->valid_legal);
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY,
&sign_key_issue.purpose,
&sign_key_issue_sig.eddsa_signature,
&master_key->eddsa_pub))
{
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 int
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 TALER_DenominationKeyValidityPS denom_key_issue;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("master_sig",
&denom_key->master_sig),
GNUNET_JSON_spec_absolute_time ("stamp_expire_deposit",
&denom_key->expire_deposit),
GNUNET_JSON_spec_absolute_time ("stamp_expire_withdraw",
&denom_key->withdraw_valid_until),
GNUNET_JSON_spec_absolute_time ("stamp_start",
&denom_key->valid_from),
GNUNET_JSON_spec_absolute_time ("stamp_expire_legal",
&denom_key->expire_legal),
TALER_JSON_spec_amount ("value",
&denom_key->value),
TALER_JSON_spec_amount ("fee_withdraw",
&denom_key->fee_withdraw),
TALER_JSON_spec_amount ("fee_deposit",
&denom_key->fee_deposit),
TALER_JSON_spec_amount ("fee_refresh",
&denom_key->fee_refresh),
TALER_JSON_spec_amount ("fee_refund",
&denom_key->fee_refund),
GNUNET_JSON_spec_rsa_public_key ("denom_pub",
&denom_key->key.rsa_public_key),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (denom_key_obj,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
GNUNET_CRYPTO_rsa_public_key_hash (denom_key->key.rsa_public_key,
&denom_key->h_key);
if (! check_sigs)
return GNUNET_OK;
memset (&denom_key_issue,
0,
sizeof (denom_key_issue));
denom_key_issue.purpose.purpose
= htonl (TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY);
denom_key_issue.purpose.size
= htonl (sizeof (struct TALER_DenominationKeyValidityPS));
denom_key_issue.master = *master_key;
denom_key_issue.denom_hash = denom_key->h_key;
denom_key_issue.start = GNUNET_TIME_absolute_hton (denom_key->valid_from);
denom_key_issue.expire_withdraw = GNUNET_TIME_absolute_hton (
denom_key->withdraw_valid_until);
denom_key_issue.expire_deposit = GNUNET_TIME_absolute_hton (
denom_key->expire_deposit);
denom_key_issue.expire_legal = GNUNET_TIME_absolute_hton (
denom_key->expire_legal);
TALER_amount_hton (&denom_key_issue.value,
&denom_key->value);
TALER_amount_hton (&denom_key_issue.fee_withdraw,
&denom_key->fee_withdraw);
TALER_amount_hton (&denom_key_issue.fee_deposit,
&denom_key->fee_deposit);
TALER_amount_hton (&denom_key_issue.fee_refresh,
&denom_key->fee_refresh);
TALER_amount_hton (&denom_key_issue.fee_refund,
&denom_key->fee_refund);
EXITIF (GNUNET_SYSERR ==
GNUNET_CRYPTO_eddsa_verify (
TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY,
&denom_key_issue.purpose,
&denom_key->master_sig.eddsa_signature,
&master_key->eddsa_pub));
GNUNET_CRYPTO_hash_context_read (hash_context,
&denom_key_issue.denom_hash,
sizeof (struct GNUNET_HashCode));
return GNUNET_OK;
EXITIF_exit:
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 int
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 TALER_ExchangeKeyValidityPS kv;
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);
return GNUNET_SYSERR;
}
auditor->auditor_url = GNUNET_strdup (auditor_url);
kv.purpose.purpose = htonl (TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS);
kv.purpose.size = htonl (sizeof (struct TALER_ExchangeKeyValidityPS));
GNUNET_CRYPTO_hash (auditor_url,
strlen (auditor_url) + 1,
&kv.auditor_url_hash);
kv.master = key_data->master_pub;
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 GNUNET_HashCode 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; j<key_data->num_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_break_op (0);
continue;
}
if (check_sigs)
{
kv.start = GNUNET_TIME_absolute_hton (dk->valid_from);
kv.expire_withdraw = GNUNET_TIME_absolute_hton (dk->withdraw_valid_until);
kv.expire_deposit = GNUNET_TIME_absolute_hton (dk->expire_deposit);
kv.expire_legal = GNUNET_TIME_absolute_hton (dk->expire_legal);
TALER_amount_hton (&kv.value,
&dk->value);
TALER_amount_hton (&kv.fee_withdraw,
&dk->fee_withdraw);
TALER_amount_hton (&kv.fee_deposit,
&dk->fee_deposit);
TALER_amount_hton (&kv.fee_refresh,
&dk->fee_refresh);
TALER_amount_hton (&kv.fee_refund,
&dk->fee_refund);
kv.denom_hash = dk->h_key;
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS,
&kv.purpose,
&auditor_sig.eddsa_sig,
&auditor->auditor_pub.eddsa_pub))
{
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 vi basic information about the auditor
* @param compat protocol compatibility information
*/
static void
auditor_version_cb
(void *cls,
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; i<kd->num_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.
*
* @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 (struct TALER_EXCHANGE_DenomPublicKey *denom1,
struct TALER_EXCHANGE_DenomPublicKey *denom2)
{
struct GNUNET_CRYPTO_RsaPublicKey *tmp1;
struct GNUNET_CRYPTO_RsaPublicKey *tmp2;
/* First check if pub is the same. */
if (0 != GNUNET_CRYPTO_rsa_public_key_cmp
(denom1->key.rsa_public_key,
denom2->key.rsa_public_key))
return 1;
tmp1 = denom1->key.rsa_public_key;
tmp2 = denom2->key.rsa_public_key;
denom1->key.rsa_public_key = NULL;
denom2->key.rsa_public_key = NULL;
/* Then procede with the rest of the object. */
if (0 != GNUNET_memcmp (denom1,
denom2))
{
denom1->key.rsa_public_key = tmp1;
denom2->key.rsa_public_key = tmp2;
return 1;
}
denom1->key.rsa_public_key = tmp1;
denom2->key.rsa_public_key = tmp2;
return 0;
}
/**
* 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 #GNUNET_YES 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 int
decode_keys_json (const json_t *resp_obj,
int 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;
unsigned int age;
unsigned int revision;
unsigned int current;
struct GNUNET_JSON_Specification mspec[] = {
GNUNET_JSON_spec_fixed_auto ("eddsa_sig",
&sig),
GNUNET_JSON_spec_fixed_auto ("eddsa_pub",
&pub),
/* sig and pub must be first, as we skip those if
check_sig is false! */
GNUNET_JSON_spec_fixed_auto ("master_public_key",
&key_data->master_pub),
GNUNET_JSON_spec_absolute_time ("list_issue_date",
&key_data->list_issue_date),
GNUNET_JSON_spec_relative_time ("reserve_closing_delay",
&key_data->reserve_closing_delay),
GNUNET_JSON_spec_end ()
};
if (JSON_OBJECT != json_typeof (resp_obj))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
/* check the version */
{
const char *ver;
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",
&current,
&revision,
&age))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
*vc = TALER_EXCHANGE_VC_MATCH;
if (TALER_PROTOCOL_CURRENT < current)
{
*vc |= TALER_EXCHANGE_VC_NEWER;
if (TALER_PROTOCOL_CURRENT < current - age)
*vc |= TALER_EXCHANGE_VC_INCOMPATIBLE;
}
if (TALER_PROTOCOL_CURRENT > current)
{
*vc |= TALER_EXCHANGE_VC_OLDER;
if (TALER_PROTOCOL_CURRENT - TALER_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));
/* 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));
EXITIF (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;
int found = GNUNET_NO;
EXITIF (GNUNET_SYSERR ==
parse_json_denomkey (&dk,
check_sig,
denom_key_obj,
&key_data->master_pub,
hash_context));
for (unsigned int j = 0;
j<key_data->num_denom_keys;
j++)
{
if (0 == denoms_cmp (&dk,
&key_data->denom_keys[j]))
{
found = GNUNET_YES;
break;
}
}
if (GNUNET_YES == found)
{
/* 0:0:0 did not support /keys cherry picking */
/* Okay, but why breaking here? It could be that the
* user redownloaded all the keys in a forced way. */
GNUNET_break_op (0 == current);
GNUNET_CRYPTO_rsa_public_key_free (dk.key.rsa_public_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 ("Crawling DK '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;
int found = GNUNET_NO;
memset (&ai,
0,
sizeof (ai));
EXITIF (GNUNET_SYSERR ==
parse_json_auditor (&ai,
check_sig,
auditor_info,
key_data));
for (unsigned int j = 0; j<key_data->num_auditors; j++)
{
struct TALER_EXCHANGE_AuditorInformation *aix = &key_data->auditors[j];
if (0 == GNUNET_memcmp (&ai.auditor_pub,
&aix->auditor_pub))
{
found = GNUNET_YES;
/* Merge denomination key signatures of downloaded /keys into existing
auditor information 'aix'. */
GNUNET_array_grow (aix->denom_keys,
aix->num_denom_keys,
aix->num_denom_keys + ai.num_denom_keys);
memcpy (&aix->denom_keys[aix->num_denom_keys - ai.num_denom_keys],
ai.denom_keys,
ai.num_denom_keys * sizeof (struct
TALER_EXCHANGE_AuditorDenominationInfo));
break;
}
}
if (GNUNET_YES == 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;
};
}
if (check_sig)
{
struct TALER_ExchangeKeySetPS ks;
/* Validate signature... */
ks.purpose.size = htonl (sizeof (ks));
ks.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_KEY_SET);
ks.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.purpose,
&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; i<key_data->num_denom_keys; i++)
GNUNET_CRYPTO_rsa_public_key_free (
key_data->denom_keys[i].key.rsa_public_key);
GNUNET_array_grow (key_data->denom_keys,
key_data->denom_keys_size,
0);
for (unsigned int i = 0; i<key_data->num_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_non_null (key_data->version);
key_data->version = NULL;
}
/**
* Initiate download of /keys from the exchange.
*
* @param cls exchange where to download /keys from
*/
static void
request_keys (void *cls);
/**
* Put the handle back to the init state. Might
* be useful to force-download all /keys.
*
* @param h exchange handle.
*/
void
TEAH_handle_reset (struct TALER_EXCHANGE_Handle *h);
/**
* Set the fake now to be used when requesting "/keys".
*
* @param exchange exchange handle.
* @param now fake now to use. Note: this value will be
* used _until_ its use will be unset via @a TALER_EXCHANGE_unset_now()
*/
void
TALER_EXCHANGE_set_now (struct TALER_EXCHANGE_Handle *exchange,
struct GNUNET_TIME_Absolute now)
{
exchange->with_now = GNUNET_YES;
exchange->now = now;
}
/**
* Unset the fake now to be used when requesting "/keys".
*
* @param exchange exchange handle.
*/
void
TALER_EXCHANGE_unset_now (struct TALER_EXCHANGE_Handle *exchange)
{
exchange->with_now = GNUNET_NO;
}
/**
* 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 force_download #GNUNET_YES to force download even if /keys is still valid
* @param pull_all_keys if GNUNET_YES, then the exchange state is reset to 'init',
* and all denoms will be redownloaded.
* @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,
int force_download,
int pull_all_keys)
{
if (NULL != exchange->kr)
return GNUNET_TIME_UNIT_ZERO_ABS;
if (GNUNET_YES == pull_all_keys)
{
GNUNET_assert (GNUNET_YES == force_download);
TEAH_handle_reset (exchange);
}
if ( (GNUNET_NO == force_download) &&
(0 < GNUNET_TIME_absolute_get_remaining (
exchange->key_data_expiration).rel_value_us) )
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;
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->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:
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; i<kd_old.num_denom_keys; i++)
kd.denom_keys[i].key.rsa_public_key
= GNUNET_CRYPTO_rsa_public_key_dup (
kd_old.denom_keys[i].key.rsa_public_key);
kd.num_auditors = kd_old.num_auditors;
kd.auditors = GNUNET_new_array (kd.num_auditors,
struct TALER_EXCHANGE_AuditorInformation);
/* Now the necessary deep copy... */
for (unsigned int i = 0; i<kd_old.num_auditors; i++)
{
const struct TALER_EXCHANGE_AuditorInformation *aold =
&kd_old.auditors[i];
struct TALER_EXCHANGE_AuditorInformation *anew = &kd.auditors[i];
anew->auditor_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,
GNUNET_YES,
&kd,
&vc))
{
TALER_LOG_ERROR ("Could not decode /keys response\n");
response_code = 0;
for (unsigned int i = 0; i<kd.num_auditors; i++)
{
struct TALER_EXCHANGE_AuditorInformation *anew = &kd.auditors[i];
GNUNET_array_grow (anew->denom_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; i<kd_old.num_denom_keys; i++)
GNUNET_CRYPTO_rsa_public_key_free (kd.denom_keys[i].key.rsa_public_key);
GNUNET_array_grow (kd.denom_keys,
kd.denom_keys_size,
0);
kd.num_denom_keys = 0;
break;
}
json_decref (exchange->key_data_raw);
exchange->key_data_raw = json_deep_copy (j);
exchange->retry_delay = GNUNET_TIME_UNIT_ZERO;
break;
default:
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u\n",
(unsigned int) response_code);
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;
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,
NULL,
vc);
return;
}
exchange->kr = NULL;
exchange->key_data_expiration = kr->expire;
free_keys_request (kr);
exchange->state = MHS_CERT;
update_auditors (exchange);
/* notify application about the key information */
exchange->cert_cb (exchange->cert_cb_cls,
&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;
}
/**
* Put the handle back to the init state. Might
* be useful to force-download all /keys.
*
* @param h exchange handle.
*/
void
TEAH_handle_reset (struct TALER_EXCHANGE_Handle *h)
{
h->state = MHS_INIT;
}
/**
* 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
*/
int
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)
{
char *ret;
GNUNET_assert ('/' == path[0]);
ret = TALER_url_join (h->url,
path + 1,
NULL);
GNUNET_assert (NULL != ret);
return ret;
}
/**
* Parse HTTP timestamp.
*
* @param date header to parse header
* @param at where to write the result
* @return #GNUNET_OK on success
*/
static int
parse_date_string (const char *date,
struct GNUNET_TIME_Absolute *at)
{
struct tm now;
time_t t;
const char *end;
memset (&now,
0,
sizeof (now));
end = strptime (date,
"%a, %d %b %Y %H:%M:%S %Z", /* RFC-1123 standard spec */
&now);
if ( (NULL == end) ||
( (*end != '\n') &&
(*end != '\r') ) )
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
t = mktime (&now);
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 fo 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),
GNUNET_JSON_spec_absolute_time ("expire",
&expire),
GNUNET_JSON_spec_end ()
};
struct TALER_EXCHANGE_Keys key_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,
GNUNET_NO,
&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;
update_auditors (exchange);
/* notify application about the key information */
exchange->cert_cb (exchange->cert_cb_cls,
&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; i<kd->num_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 = json_pack ("{s:o, s:o, s:o, s:o, s:o}",
"key",
GNUNET_JSON_from_data_auto
(&sk->key),
"master_sig",
GNUNET_JSON_from_data_auto
(&sk->master_sig),
"stamp_start",
GNUNET_JSON_from_time_abs
(sk->valid_from),
"stamp_expire",
GNUNET_JSON_from_time_abs
(sk->valid_until),
"stamp_end",
GNUNET_JSON_from_time_abs
(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; i<kd->num_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 = json_pack ("{s:o, s:o, s:o, s:o, s:o "
",s:o, s:o, s:o, s:o, s:o "
",s:o}",
"stamp_expire_deposit",
GNUNET_JSON_from_time_abs (dk->expire_deposit),
"stamp_expire_withdraw",
GNUNET_JSON_from_time_abs (dk->withdraw_valid_until),
"stamp_start",
GNUNET_JSON_from_time_abs (dk->valid_from),
"stamp_expire_legal",
GNUNET_JSON_from_time_abs (dk->expire_legal),
"value",
TALER_JSON_from_amount (&dk->value),
"fee_withdraw",
/* #6 */
TALER_JSON_from_amount (&dk->fee_withdraw),
"fee_deposit",
TALER_JSON_from_amount (&dk->fee_deposit),
"fee_refresh",
TALER_JSON_from_amount (&dk->fee_refresh),
"fee_refund",
TALER_JSON_from_amount (&dk->fee_refund),
"master_sig",
GNUNET_JSON_from_data_auto (&dk->master_sig),
/* #10 */
"denom_pub",
GNUNET_JSON_from_rsa_public_key (
dk->key.rsa_public_key));
if (NULL == denom)
{
GNUNET_break (0);
continue;
}
if (0 != json_array_append_new (denoms,
denom))
{
GNUNET_break (0);
json_decref (denom);
json_decref (denoms);
json_decref (signkeys);
return NULL;
}
}
auditors = json_array ();
if (NULL == auditors)
{
GNUNET_break (0);
json_decref (denoms);
json_decref (signkeys);
return NULL;
}
for (unsigned int i = 0; i<kd->num_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; j<ai->num_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 = json_pack ("{s:o, s:o}",
"denom_pub_h",
GNUNET_JSON_from_data_auto (&dk->h_key),
"auditor_sig",
GNUNET_JSON_from_data_auto (&adi->auditor_sig));
if (NULL == k)
{
GNUNET_break (0);
json_decref (adenoms);
json_decref (denoms);
json_decref (signkeys);
json_decref (auditors);
return NULL;
}
if (0 != json_array_append_new (adenoms,
k))
{
GNUNET_break (0);
json_decref (k);
json_decref (adenoms);
json_decref (denoms);
json_decref (signkeys);
json_decref (auditors);
return NULL;
}
}
a = json_pack ("{s:o, s:s, s:o}",
"auditor_pub",
GNUNET_JSON_from_data_auto (&ai->auditor_pub),
"auditor_url",
ai->auditor_url,
"denomination_keys",
adenoms);
if (NULL == a)
{
json_decref (adenoms);
json_decref (denoms);
json_decref (signkeys);
json_decref (auditors);
return NULL;
}
if (0 != json_array_append_new (auditors,
a))
{
json_decref (a);
json_decref (denoms);
json_decref (signkeys);
json_decref (auditors);
return NULL;
}
}
keys = json_pack ("{s:s, s:o, s:o, s:o, s:o"
",s:o, s:o}",
/* 1 */
"version",
kd->version,
"master_public_key",
GNUNET_JSON_from_data_auto (&kd->master_pub),
"reserve_closing_delay",
GNUNET_JSON_from_time_rel (kd->reserve_closing_delay),
"list_issue_date",
GNUNET_JSON_from_time_abs (kd->list_issue_date),
"signkeys",
signkeys,
/* #6 */
"denoms",
denoms,
"auditors",
auditors);
if (NULL == keys)
{
GNUNET_break (0);
return NULL;
}
return json_pack ("{s:I, s:o, s:s, s:o}",
"version",
(json_int_t) TALER_SERIALIZATION_FORMAT_VERSION,
"expire",
GNUNET_JSON_from_time_abs (exchange->key_data_expiration),
"exchange_url",
exchange->url,
"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;
}
/**
* 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);
}
if (GNUNET_YES == exchange->with_now)
{
TALER_LOG_DEBUG ("Faking now to GET /keys: %s\n",
GNUNET_STRINGS_absolute_time_to_string (exchange->now));
sprintf (&url[strlen (url)],
"now=%llu&",
(unsigned long long) exchange->now.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);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Requesting keys with URL `%s'.\n",
kr->url);
eh = TALER_EXCHANGE_curl_easy_get_ (kr->url);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_VERBOSE,
0));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_TIMEOUT,
(long) 300));
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 (exchange->ctx,
eh,
GNUNET_YES,
&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
*/
int
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; i<keys->num_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;
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; i<keys->num_denom_keys; i++)
if (0 == GNUNET_CRYPTO_rsa_public_key_cmp (pk->rsa_public_key,
keys->denom_keys[i].key.
rsa_public_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;
copy->key.rsa_public_key = GNUNET_CRYPTO_rsa_public_key_dup (
key->key.rsa_public_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)
{
GNUNET_CRYPTO_rsa_public_key_free (key->key.rsa_public_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 GNUNET_HashCode *hc)
{
for (unsigned int i = 0; i<keys->num_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,
GNUNET_NO,
GNUNET_NO);
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,
GNUNET_NO,
GNUNET_NO);
return json_deep_copy (exchange->key_data_raw);
}
/* end of exchange_api_handle.c */
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