/*
This file is part of TALER
Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, If not, see
*/
/**
* @file mint-lib/mint_api_deposit.c
* @brief Implementation of the /deposit request of the mint's HTTP API
* @author Sree Harsha Totakura
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include /* just for HTTP status codes */
#include
#include "taler_mint_service.h"
#include "mint_api_common.h"
#include "mint_api_json.h"
#include "mint_api_context.h"
#include "mint_api_handle.h"
#include "taler_signatures.h"
/**
* @brief A Deposit Handle
*/
struct TALER_MINT_DepositHandle
{
/**
* The connection to mint this request handle will use
*/
struct TALER_MINT_Handle *mint;
/**
* The url for this request.
*/
char *url;
/**
* JSON encoding of the request to POST.
*/
char *json_enc;
/**
* Handle for the request.
*/
struct MAC_Job *job;
/**
* Function to call with the result.
*/
TALER_MINT_DepositResultCallback cb;
/**
* Closure for @a cb.
*/
void *cb_cls;
/**
* Download buffer
*/
struct MAC_DownloadBuffer db;
/**
* Information the mint should sign in response.
*/
struct TALER_DepositConfirmationPS depconf;
/**
* Value of the /deposit transaction, including fee.
*/
struct TALER_Amount amount_with_fee;
/**
* Total value of the coin being transacted with.
*/
struct TALER_Amount coin_value;
};
/**
* Verify that the signature on the "200 OK" response
* from the mint is valid.
*
* @param dh deposit handle
* @param json json reply with the signature
* @return #GNUNET_OK if the signature is valid, #GNUNET_SYSERR if not
*/
static int
verify_deposit_signature_ok (const struct TALER_MINT_DepositHandle *dh,
json_t *json)
{
struct TALER_MintSignatureP mint_sig;
struct TALER_MintPublicKeyP mint_pub;
const struct TALER_MINT_Keys *key_state;
struct MAJ_Specification spec[] = {
MAJ_spec_fixed_auto ("sig", &mint_sig),
MAJ_spec_fixed_auto ("pub", &mint_pub),
MAJ_spec_end
};
if (GNUNET_OK !=
MAJ_parse_json (json,
spec))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
key_state = TALER_MINT_get_keys (dh->mint);
if (GNUNET_OK !=
TALER_MINT_test_signing_key (key_state,
&mint_pub))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MINT_CONFIRM_DEPOSIT,
&dh->depconf.purpose,
&mint_sig.eddsa_signature,
&mint_pub.eddsa_pub))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Verify that the signatures on the "403 FORBIDDEN" response from the
* mint demonstrating customer double-spending are valid.
*
* @param dh deposit handle
* @param json json reply with the signature(s) and transaction history
* @return #GNUNET_OK if the signature(s) is valid, #GNUNET_SYSERR if not
*/
static int
verify_deposit_signature_forbidden (const struct TALER_MINT_DepositHandle *dh,
json_t *json)
{
json_t *history;
struct TALER_Amount total;
history = json_object_get (json,
"history");
if (GNUNET_OK !=
TALER_MINT_verify_coin_history_ (dh->coin_value.currency,
&dh->depconf.coin_pub,
history,
&total))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_amount_add (&total,
&total,
&dh->amount_with_fee))
{
/* clearly not OK if our transaction would have caused
the overflow... */
return GNUNET_OK;
}
if (0 >= TALER_amount_cmp (&total,
&dh->coin_value))
{
/* transaction should have still fit */
GNUNET_break (0);
return GNUNET_SYSERR;
}
/* everything OK, proof of double-spending was provided */
return GNUNET_OK;
}
/**
* Function called when we're done processing the
* HTTP /deposit request.
*
* @param cls the `struct TALER_MINT_DepositHandle`
* @param eh the curl request handle
*/
static void
handle_deposit_finished (void *cls,
CURL *eh)
{
struct TALER_MINT_DepositHandle *dh = cls;
long response_code;
json_t *json;
dh->job = NULL;
json = MAC_download_get_result (&dh->db,
eh,
&response_code);
switch (response_code)
{
case 0:
break;
case MHD_HTTP_OK:
if (GNUNET_OK !=
verify_deposit_signature_ok (dh,
json))
{
GNUNET_break_op (0);
response_code = 0;
}
break;
case MHD_HTTP_BAD_REQUEST:
/* This should never happen, either us or the mint is buggy
(or API version conflict); just pass JSON reply to the application */
break;
case MHD_HTTP_FORBIDDEN:
/* Double spending; check signatures on transaction history */
if (GNUNET_OK !=
verify_deposit_signature_forbidden (dh,
json))
{
GNUNET_break_op (0);
response_code = 0;
}
break;
case MHD_HTTP_UNAUTHORIZED:
/* Nothing really to verify, mint says one of the signatures is
invalid; as we checked them, this should never happen, we
should pass the JSON reply to the application */
break;
case MHD_HTTP_NOT_FOUND:
/* Nothing really to verify, this should never
happen, we should pass the JSON reply to the application */
break;
case MHD_HTTP_INTERNAL_SERVER_ERROR:
/* Server had an internal issue; we should retry, but this API
leaves this to the application */
break;
default:
/* unexpected response code */
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u\n",
response_code);
GNUNET_break (0);
response_code = 0;
break;
}
dh->cb (dh->cb_cls,
response_code,
json);
json_decref (json);
TALER_MINT_deposit_cancel (dh);
}
/**
* Verify signature information about the deposit.
*
* @param dki public key information
* @param amount the amount to be deposited
* @param h_wire hash of the merchant’s account details
* @param h_contract hash of the contact of the merchant with the customer (further details are never disclosed to the mint)
* @param coin_pub coin’s public key
* @param denom_pub denomination key with which the coin is signed
* @param denom_sig mint’s unblinded signature of the coin
* @param timestamp timestamp when the contract was finalized, must match approximately the current time of the mint
* @param transaction_id transaction id for the transaction between merchant and customer
* @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
* @param refund_deadline date until which the merchant can issue a refund to the customer via the mint (can be zero if refunds are not allowed)
* @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT made by the customer with the coin’s private key.
* @return #GNUNET_OK if signatures are OK, #GNUNET_SYSERR if not
*/
static int
verify_signatures (const struct TALER_MINT_DenomPublicKey *dki,
const struct TALER_Amount *amount,
const struct GNUNET_HashCode *h_wire,
const struct GNUNET_HashCode *h_contract,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const struct TALER_DenominationSignature *denom_sig,
const struct TALER_DenominationPublicKey *denom_pub,
struct GNUNET_TIME_Absolute timestamp,
uint64_t transaction_id,
const struct TALER_MerchantPublicKeyP *merchant_pub,
struct GNUNET_TIME_Absolute refund_deadline,
const struct TALER_CoinSpendSignatureP *coin_sig)
{
struct TALER_DepositRequestPS dr;
struct TALER_CoinPublicInfo coin_info;
dr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT);
dr.purpose.size = htonl (sizeof (struct TALER_DepositRequestPS));
dr.h_contract = *h_contract;
dr.h_wire = *h_wire;
dr.timestamp = GNUNET_TIME_absolute_hton (timestamp);
dr.refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline);
dr.transaction_id = GNUNET_htonll (transaction_id);
TALER_amount_hton (&dr.amount_with_fee,
amount);
TALER_amount_hton (&dr.deposit_fee,
&dki->fee_deposit);
dr.merchant = *merchant_pub;
dr.coin_pub = *coin_pub;
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_DEPOSIT,
&dr.purpose,
&coin_sig->eddsa_signature,
&coin_pub->eddsa_pub))
{
TALER_LOG_WARNING ("Invalid coin signature on /deposit request\n");
{
char *s;
s = TALER_amount_to_string (amount);
TALER_LOG_DEBUG ("... amount_with_fee was %s\n", s);
GNUNET_free (s);
s = TALER_amount_to_string (&dki->fee_deposit);
TALER_LOG_DEBUG ("... deposit_fee was %s\n", s);
GNUNET_free (s);
}
return GNUNET_SYSERR;
}
/* check coin signature */
coin_info.coin_pub = *coin_pub;
coin_info.denom_pub = *denom_pub;
coin_info.denom_sig = *denom_sig;
if (GNUNET_YES !=
TALER_test_coin_valid (&coin_info))
{
TALER_LOG_WARNING ("Invalid coin passed for /deposit\n");
return GNUNET_SYSERR;
}
if (0 < TALER_amount_cmp (&dki->fee_deposit,
amount))
{
TALER_LOG_WARNING ("Deposit amount smaller than fee\n");
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Submit a deposit permission to the mint and get the mint's response.
* Note that while we return the response verbatim to the caller for
* further processing, we do already verify that the response is
* well-formed (i.e. that signatures included in the response are all
* valid). If the mint's reply is not well-formed, we return an
* HTTP status code of zero to @a cb.
*
* We also verify that the @a coin_sig is valid for this deposit
* request, and that the @a ub_sig is a valid signature for @a
* coin_pub. Also, the @a mint must be ready to operate (i.e. have
* finished processing the /keys reply). If either check fails, we do
* NOT initiate the transaction with the mint and instead return NULL.
*
* @param mint the mint handle; the mint must be ready to operate
* @param amount the amount to be deposited
* @param wire_deadline date until which the merchant would like the mint to settle the balance (advisory, the mint cannot be
* forced to settle in the past or upon very short notice, but of course a well-behaved mint will limit aggregation based on the advice received)
* @param wire_details the merchant’s account details, in a format supported by the mint
* @param h_contract hash of the contact of the merchant with the customer (further details are never disclosed to the mint)
* @param coin_pub coin’s public key
* @param denom_pub denomination key with which the coin is signed
* @param denom_sig mint’s unblinded signature of the coin
* @param timestamp timestamp when the contract was finalized, must match approximately the current time of the mint
* @param transaction_id transaction id for the transaction between merchant and customer
* @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
* @param refund_deadline date until which the merchant can issue a refund to the customer via the mint (can be zero if refunds are not allowed)
* @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT made by the customer with the coin’s private key.
* @param cb the callback to call when a reply for this request is available
* @param cb_cls closure for the above callback
* @return a handle for this request; NULL if the inputs are invalid (i.e.
* signatures fail to verify). In this case, the callback is not called.
*/
struct TALER_MINT_DepositHandle *
TALER_MINT_deposit (struct TALER_MINT_Handle *mint,
const struct TALER_Amount *amount,
struct GNUNET_TIME_Absolute wire_deadline,
json_t *wire_details,
const struct GNUNET_HashCode *h_contract,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const struct TALER_DenominationSignature *denom_sig,
const struct TALER_DenominationPublicKey *denom_pub,
struct GNUNET_TIME_Absolute timestamp,
uint64_t transaction_id,
const struct TALER_MerchantPublicKeyP *merchant_pub,
struct GNUNET_TIME_Absolute refund_deadline,
const struct TALER_CoinSpendSignatureP *coin_sig,
TALER_MINT_DepositResultCallback cb,
void *cb_cls)
{
const struct TALER_MINT_Keys *key_state;
const struct TALER_MINT_DenomPublicKey *dki;
struct TALER_MINT_DepositHandle *dh;
struct TALER_MINT_Context *ctx;
json_t *deposit_obj;
CURL *eh;
struct GNUNET_HashCode h_wire;
struct TALER_Amount amount_without_fee;
(void) TALER_round_abs_time (&wire_deadline);
if (GNUNET_YES !=
MAH_handle_is_ready (mint))
{
GNUNET_break (0);
return NULL;
}
/* initialize h_wire */
if (GNUNET_OK !=
TALER_hash_json (wire_details,
&h_wire))
{
GNUNET_break (0);
return NULL;
}
key_state = TALER_MINT_get_keys (mint);
dki = TALER_MINT_get_denomination_key (key_state,
denom_pub);
if (NULL == dki)
{
TALER_LOG_WARNING ("Denomination key unknown to mint\n");
return NULL;
}
if (GNUNET_SYSERR ==
TALER_amount_subtract (&amount_without_fee,
amount,
&dki->fee_deposit))
{
GNUNET_break (0);
return NULL;
}
if (GNUNET_OK !=
verify_signatures (dki,
amount,
&h_wire,
h_contract,
coin_pub,
denom_sig,
denom_pub,
timestamp,
transaction_id,
merchant_pub,
refund_deadline,
coin_sig))
{
GNUNET_break_op (0);
return NULL;
}
deposit_obj = json_pack ("{s:o, s:O," /* f/wire */
" s:o, s:o," /* H_wire, H_contract */
" s:o, s:o," /* coin_pub, denom_pub */
" s:o, s:o," /* ub_sig, timestamp */
" s:I, s:o," /* transaction id, merchant_pub */
" s:o, s:o," /* refund_deadline, wire_deadline */
" s:o}", /* coin_sig */
"f", TALER_json_from_amount (amount),
"wire", wire_details,
"H_wire", TALER_json_from_data (&h_wire,
sizeof (h_wire)),
"H_contract", TALER_json_from_data (h_contract,
sizeof (struct GNUNET_HashCode)),
"coin_pub", TALER_json_from_data (coin_pub,
sizeof (*coin_pub)),
"denom_pub", TALER_json_from_rsa_public_key (denom_pub->rsa_public_key),
"ub_sig", TALER_json_from_rsa_signature (denom_sig->rsa_signature),
"timestamp", TALER_json_from_abs (timestamp),
"transaction_id", (json_int_t) transaction_id,
"merchant_pub", TALER_json_from_data (merchant_pub,
sizeof (*merchant_pub)),
"refund_deadline", TALER_json_from_abs (refund_deadline),
"edate", TALER_json_from_abs (wire_deadline),
"coin_sig", TALER_json_from_data (coin_sig,
sizeof (*coin_sig))
);
dh = GNUNET_new (struct TALER_MINT_DepositHandle);
dh->mint = mint;
dh->cb = cb;
dh->cb_cls = cb_cls;
dh->url = MAH_path_to_url (mint, "/deposit");
dh->depconf.purpose.size = htonl (sizeof (struct TALER_DepositConfirmationPS));
dh->depconf.purpose.purpose = htonl (TALER_SIGNATURE_MINT_CONFIRM_DEPOSIT);
dh->depconf.h_contract = *h_contract;
dh->depconf.h_wire = h_wire;
dh->depconf.transaction_id = GNUNET_htonll (transaction_id);
dh->depconf.timestamp = GNUNET_TIME_absolute_hton (timestamp);
dh->depconf.refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline);
TALER_amount_hton (&dh->depconf.amount_without_fee,
&amount_without_fee);
dh->depconf.coin_pub = *coin_pub;
dh->depconf.merchant = *merchant_pub;
dh->amount_with_fee = *amount;
dh->coin_value = dki->value;
eh = curl_easy_init ();
GNUNET_assert (NULL != (dh->json_enc =
json_dumps (deposit_obj,
JSON_COMPACT)));
json_decref (deposit_obj);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"URL for deposit: `%s'\n",
dh->url);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_URL,
dh->url));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDS,
dh->json_enc));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDSIZE,
strlen (dh->json_enc)));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEFUNCTION,
&MAC_download_cb));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_WRITEDATA,
&dh->db));
ctx = MAH_handle_to_context (mint);
dh->job = MAC_job_add (ctx,
eh,
GNUNET_YES,
&handle_deposit_finished,
dh);
return dh;
}
/**
* Cancel a deposit permission request. This function cannot be used
* on a request handle if a response is already served for it.
*
* @param deposit the deposit permission request handle
*/
void
TALER_MINT_deposit_cancel (struct TALER_MINT_DepositHandle *deposit)
{
if (NULL != deposit->job)
{
MAC_job_cancel (deposit->job);
deposit->job = NULL;
}
GNUNET_free_non_null (deposit->db.buf);
GNUNET_free (deposit->url);
GNUNET_free (deposit->json_enc);
GNUNET_free (deposit);
}
/* end of mint_api_deposit.c */