split httpd_refresh.c into refresh_melt, refresh_link and refresh_reveal

This commit is contained in:
Christian Grothoff 2017-06-19 21:04:49 +02:00
parent 703c54a279
commit f8e62141f2
No known key found for this signature in database
GPG Key ID: 939E6BE1E29FC3CC
12 changed files with 1688 additions and 1603 deletions

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@ -50,7 +50,9 @@ taler_exchange_httpd_SOURCES = \
taler-exchange-httpd_mhd.c taler-exchange-httpd_mhd.h \ taler-exchange-httpd_mhd.c taler-exchange-httpd_mhd.h \
taler-exchange-httpd_parsing.c taler-exchange-httpd_parsing.h \ taler-exchange-httpd_parsing.c taler-exchange-httpd_parsing.h \
taler-exchange-httpd_payback.c taler-exchange-httpd_payback.h \ taler-exchange-httpd_payback.c taler-exchange-httpd_payback.h \
taler-exchange-httpd_refresh.c taler-exchange-httpd_refresh.h \ taler-exchange-httpd_refresh_link.c taler-exchange-httpd_refresh_link.h \
taler-exchange-httpd_refresh_melt.c taler-exchange-httpd_refresh_melt.h \
taler-exchange-httpd_refresh_reveal.c taler-exchange-httpd_refresh_reveal.h \
taler-exchange-httpd_refund.c taler-exchange-httpd_refund.h \ taler-exchange-httpd_refund.c taler-exchange-httpd_refund.h \
taler-exchange-httpd_reserve_status.c taler-exchange-httpd_reserve_status.h \ taler-exchange-httpd_reserve_status.c taler-exchange-httpd_reserve_status.h \
taler-exchange-httpd_reserve_withdraw.c taler-exchange-httpd_reserve_withdraw.h \ taler-exchange-httpd_reserve_withdraw.c taler-exchange-httpd_reserve_withdraw.h \

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@ -34,11 +34,13 @@
#include "taler-exchange-httpd_reserve_status.h" #include "taler-exchange-httpd_reserve_status.h"
#include "taler-exchange-httpd_reserve_withdraw.h" #include "taler-exchange-httpd_reserve_withdraw.h"
#include "taler-exchange-httpd_payback.h" #include "taler-exchange-httpd_payback.h"
#include "taler-exchange-httpd_wire.h" #include "taler-exchange-httpd_refresh_link.h"
#include "taler-exchange-httpd_refresh.h" #include "taler-exchange-httpd_refresh_melt.h"
#include "taler-exchange-httpd_refresh_reveal.h"
#include "taler-exchange-httpd_track_transfer.h" #include "taler-exchange-httpd_track_transfer.h"
#include "taler-exchange-httpd_track_transaction.h" #include "taler-exchange-httpd_track_transaction.h"
#include "taler-exchange-httpd_keystate.h" #include "taler-exchange-httpd_keystate.h"
#include "taler-exchange-httpd_wire.h"
#if HAVE_DEVELOPER #if HAVE_DEVELOPER
#include "taler-exchange-httpd_test.h" #include "taler-exchange-httpd_test.h"
#endif #endif

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@ -32,85 +32,6 @@
*/ */
#define MAX_TRANSACTION_COMMIT_RETRIES 3 #define MAX_TRANSACTION_COMMIT_RETRIES 3
/**
* Code to begin a transaction, must be inline as we define a block
* that ends with #COMMIT_TRANSACTION() within which we perform a number
* of retries. Note that this code may call "return" internally, so
* it must be called within a function where any cleanup will be done
* by the caller. Furthermore, the function's return value must
* match that of a #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define START_TRANSACTION(session,connection) \
{ /* start new scope, will be ended by COMMIT_TRANSACTION() */\
unsigned int transaction_retries = 0; \
enum GNUNET_DB_QueryStatus transaction_commit_result; \
transaction_start_label: /* we will use goto for retries */ \
if (GNUNET_OK != \
TEH_plugin->start (TEH_plugin->cls, \
session)) \
{ \
GNUNET_break (0); \
return TEH_RESPONSE_reply_internal_db_error (connection, \
TALER_EC_DB_START_FAILED); \
}
/**
* Code to conclude a transaction, dual to #START_TRANSACTION(). Note
* that this code may call "return" internally, so it must be called
* within a function where any cleanup will be done by the caller.
* Furthermore, the function's return value must match that of a
* #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define COMMIT_TRANSACTION(session,connection) \
transaction_commit_result = \
TEH_plugin->commit (TEH_plugin->cls, \
session); \
if (GNUNET_DB_STATUS_HARD_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_HARD); \
} \
if (GNUNET_DB_STATUS_SOFT_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} \
} /* end of scope opened by BEGIN_TRANSACTION */
/**
* Code to include to retry a transaction, must only be used in between
* #START_TRANSACTION and #COMMIT_TRANSACTION.
*
* @param session session handle
* @param connection connection handle
*/
#define RETRY_TRANSACTION(session,connection) \
do { \
TEH_plugin->rollback (TEH_plugin->cls, \
session); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} while (0)
/** /**
* Run a database transaction for @a connection. * Run a database transaction for @a connection.
@ -279,870 +200,4 @@ TEH_DB_calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionLis
} }
/**
* Parse coin melt requests from a JSON object and write them to
* the database.
*
* @param connection the connection to send errors to
* @param session the database connection
* @param key_state the exchange's key state
* @param session_hash hash identifying the refresh session
* @param coin_details details about the coin being melted
* @param[out] meltp on success, set to melt details
* @return #GNUNET_OK on success,
* #GNUNET_NO if an error message was generated,
* #GNUNET_SYSERR on internal errors (no response generated)
*/
static int
refresh_check_melt (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct TEH_KS_StateHandle *key_state,
const struct GNUNET_HashCode *session_hash,
const struct TEH_DB_MeltDetails *coin_details,
struct TALER_EXCHANGEDB_RefreshMelt *meltp)
{
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dk;
struct TALER_EXCHANGEDB_DenominationKeyInformationP *dki;
struct TALER_EXCHANGEDB_TransactionList *tl;
struct TALER_Amount coin_value;
struct TALER_Amount coin_residual;
struct TALER_Amount spent;
int res;
enum GNUNET_DB_QueryStatus qs;
dk = TEH_KS_denomination_key_lookup (key_state,
&coin_details->coin_info.denom_pub,
TEH_KS_DKU_DEPOSIT);
if (NULL == dk)
return (MHD_YES ==
TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_REFRESH_MELT_DB_DENOMINATION_KEY_NOT_FOUND,
"denomination key no longer available while executing transaction"))
? GNUNET_NO : GNUNET_SYSERR;
dki = &dk->issue;
TALER_amount_ntoh (&coin_value,
&dki->properties.value);
/* fee for THIS transaction; the melt amount includes the fee! */
spent = coin_details->melt_amount_with_fee;
/* add historic transaction costs of this coin */
qs = TEH_plugin->get_coin_transactions (TEH_plugin->cls,
session,
&coin_details->coin_info.coin_pub,
&tl);
(void) qs; /* FIXME #5010 */
if (GNUNET_OK !=
TEH_DB_calculate_transaction_list_totals (tl,
&spent,
&spent))
{
GNUNET_break (0);
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
return (MHD_YES ==
TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_COIN_HISTORY_COMPUTATION_FAILED))
? GNUNET_NO : GNUNET_SYSERR;
}
/* Refuse to refresh when the coin's value is insufficient
for the cost of all transactions. */
if (TALER_amount_cmp (&coin_value,
&spent) < 0)
{
GNUNET_assert (GNUNET_SYSERR !=
TALER_amount_subtract (&coin_residual,
&spent,
&coin_details->melt_amount_with_fee));
res = (MHD_YES ==
TEH_RESPONSE_reply_refresh_melt_insufficient_funds (connection,
&coin_details->coin_info.coin_pub,
coin_value,
tl,
coin_details->melt_amount_with_fee,
coin_residual))
? GNUNET_NO : GNUNET_SYSERR;
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
return res;
}
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
meltp->coin = coin_details->coin_info;
meltp->coin_sig = coin_details->melt_sig;
meltp->session_hash = *session_hash;
meltp->amount_with_fee = coin_details->melt_amount_with_fee;
meltp->melt_fee = coin_details->melt_fee;
return GNUNET_OK;
}
/**
* Execute a "/refresh/melt". We have been given a list of valid
* coins and a request to melt them into the given
* @a refresh_session_pub. Check that the coins all have the
* required value left and if so, store that they have been
* melted and confirm the melting operation to the client.
*
* @param connection the MHD connection to handle
* @param session_hash hash code of the session the coins are melted into
* @param num_new_denoms number of entries in @a denom_pubs, size of y-dimension of @a commit_coin array
* @param denom_pubs public keys of the coins we want to withdraw in the end
* @param coin_melt_detail signature and (residual) value of the respective coin should be melted
* @param commit_coin 2d array of coin commitments (what the exchange is to sign
* once the "/refres/reveal" of cut and choose is done),
* x-dimension must be #TALER_CNC_KAPPA
* @param transfer_pubs array of transfer public keys (what the exchange is
* to return via "/refresh/link" to enable linkage in the
* future) of length #TALER_CNC_KAPPA
* @return MHD result code
*/
int
TEH_DB_execute_refresh_melt (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
unsigned int num_new_denoms,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TEH_DB_MeltDetails *coin_melt_detail,
struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
const struct TALER_TransferPublicKeyP *transfer_pubs)
{
struct TEH_KS_StateHandle *key_state;
struct TALER_EXCHANGEDB_RefreshSession refresh_session;
struct TALER_EXCHANGEDB_Session *session;
int res;
if (NULL == (session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
START_TRANSACTION (session, connection);
res = TEH_plugin->get_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session);
if (GNUNET_YES == res)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
res = TEH_RESPONSE_reply_refresh_melt_success (connection,
session_hash,
refresh_session.noreveal_index);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
if (GNUNET_SYSERR == res)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_FETCH_ERROR);
}
/* store 'global' session data */
refresh_session.num_newcoins = num_new_denoms;
refresh_session.noreveal_index
= GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG,
TALER_CNC_KAPPA);
key_state = TEH_KS_acquire ();
if (GNUNET_OK !=
(res = refresh_check_melt (connection,
session,
key_state,
session_hash,
coin_melt_detail,
&refresh_session.melt)))
{
TEH_KS_release (key_state);
TEH_plugin->rollback (TEH_plugin->cls,
session);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
TEH_KS_release (key_state);
if (GNUNET_OK !=
(res = TEH_plugin->create_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session)))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_SESSION_ERROR);
}
/* store requested new denominations */
if (GNUNET_OK !=
TEH_plugin->insert_refresh_order (TEH_plugin->cls,
session,
session_hash,
num_new_denoms,
denom_pubs))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_ORDER_ERROR);
}
if (GNUNET_OK !=
TEH_plugin->insert_refresh_commit_coins (TEH_plugin->cls,
session,
session_hash,
num_new_denoms,
commit_coin[refresh_session.noreveal_index]))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_ORDER_ERROR);
}
if (GNUNET_OK !=
TEH_plugin->insert_refresh_transfer_public_key (TEH_plugin->cls,
session,
session_hash,
&transfer_pubs[refresh_session.noreveal_index]))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_TRANSFER_ERROR);
}
COMMIT_TRANSACTION (session, connection);
return TEH_RESPONSE_reply_refresh_melt_success (connection,
session_hash,
refresh_session.noreveal_index);
}
/**
* Check if the given @a transfer_privs correspond to an honest
* commitment for the given session.
* Checks that the transfer private keys match their commitments.
* Then derives the shared secret for each #TALER_CNC_KAPPA, and check that they match.
*
* @param connection the MHD connection to handle
* @param session database connection to use
* @param session_hash hash of session to query
* @param off commitment offset to check
* @param transfer_priv private transfer key
* @param melt information about the melted coin
* @param num_newcoins number of newcoins being generated
* @param denom_pubs array of @a num_newcoins keys for the new coins
* @param hash_context hash context to update by hashing in the data
* from this offset
* @return #GNUNET_OK if the committment was honest,
* #GNUNET_NO if there was a problem and we generated an error message
* #GNUNET_SYSERR if we could not even generate an error message
*/
static int
check_commitment (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
unsigned int off,
const struct TALER_TransferPrivateKeyP *transfer_priv,
const struct TALER_EXCHANGEDB_RefreshMelt *melt,
unsigned int num_newcoins,
const struct TALER_DenominationPublicKey *denom_pubs,
struct GNUNET_HashContext *hash_context)
{
struct TALER_TransferSecretP transfer_secret;
unsigned int j;
TALER_link_reveal_transfer_secret (transfer_priv,
&melt->coin.coin_pub,
&transfer_secret);
/* Check that the commitments for all new coins were correct */
for (j = 0; j < num_newcoins; j++)
{
struct TALER_FreshCoinP fc;
struct TALER_CoinSpendPublicKeyP coin_pub;
struct GNUNET_HashCode h_msg;
char *buf;
size_t buf_len;
TALER_setup_fresh_coin (&transfer_secret,
j,
&fc);
GNUNET_CRYPTO_eddsa_key_get_public (&fc.coin_priv.eddsa_priv,
&coin_pub.eddsa_pub);
GNUNET_CRYPTO_hash (&coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP),
&h_msg);
if (GNUNET_YES !=
GNUNET_CRYPTO_rsa_blind (&h_msg,
&fc.blinding_key.bks,
denom_pubs[j].rsa_public_key,
&buf,
&buf_len))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Blind failed (bad denomination key!?)\n");
return (MHD_YES ==
TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_REFRESH_REVEAL_BLINDING_ERROR,
"Blinding error"))
? GNUNET_NO : GNUNET_SYSERR;
}
GNUNET_CRYPTO_hash_context_read (hash_context,
buf,
buf_len);
GNUNET_free (buf);
}
return GNUNET_OK;
}
/**
* Exchange a coin as part of a refresh operation. Obtains the
* envelope from the database and performs the signing operation.
*
* @param connection the MHD connection to handle
* @param session database connection to use
* @param session_hash hash of session to query
* @param key_state key state to lookup denomination pubs
* @param denom_pub denomination key for the coin to create
* @param commit_coin the coin that was committed
* @param coin_off number of the coin
* @return NULL on error, otherwise signature over the coin
*/
static struct TALER_DenominationSignature
refresh_exchange_coin (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
struct TEH_KS_StateHandle *key_state,
const struct TALER_DenominationPublicKey *denom_pub,
const struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coin,
unsigned int coin_off)
{
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
struct TALER_DenominationSignature ev_sig;
dki = TEH_KS_denomination_key_lookup (key_state,
denom_pub,
TEH_KS_DKU_WITHDRAW);
if (NULL == dki)
{
GNUNET_break (0);
ev_sig.rsa_signature = NULL;
return ev_sig;
}
if (GNUNET_OK ==
TEH_plugin->get_refresh_out (TEH_plugin->cls,
session,
session_hash,
coin_off,
&ev_sig))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Returning cached reply for /refresh/reveal signature\n");
return ev_sig;
}
ev_sig.rsa_signature
= GNUNET_CRYPTO_rsa_sign_blinded (dki->denom_priv.rsa_private_key,
commit_coin->coin_ev,
commit_coin->coin_ev_size);
if (NULL == ev_sig.rsa_signature)
{
GNUNET_break (0);
return ev_sig;
}
if (GNUNET_SYSERR ==
TEH_plugin->insert_refresh_out (TEH_plugin->cls,
session,
session_hash,
coin_off,
&ev_sig))
{
GNUNET_break (0);
GNUNET_CRYPTO_rsa_signature_free (ev_sig.rsa_signature);
ev_sig.rsa_signature = NULL;
}
return ev_sig;
}
/**
* The client request was well-formed, now execute the DB transaction
* of a "/refresh/reveal" operation. We use the @a ev_sigs and
* @a commit_coins to clean up resources after this function returns
* as we might experience retries of the database transaction.
*
* @param connection the MHD connection to handle
* @param session database session
* @param session_hash hash identifying the refresh session
* @param refresh_session information about the refresh operation we are doing
* @param denom_pubs array of "num_newcoins" denomination keys for the new coins
* @param[out] ev_sigs where to store generated signatures for the new coins,
* array of length "num_newcoins", memory released by the
* caller
* @param[out] commit_coins array of length "num_newcoins" to be used for
* information about the new coins from the commitment.
* @return MHD result code
*/
static int
execute_refresh_reveal_transaction (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
const struct TALER_EXCHANGEDB_RefreshSession *refresh_session,
const struct TALER_DenominationPublicKey *denom_pubs,
struct TALER_DenominationSignature *ev_sigs,
struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins)
{
unsigned int j;
struct TEH_KS_StateHandle *key_state;
int ret;
START_TRANSACTION (session, connection);
key_state = TEH_KS_acquire ();
for (j=0;j<refresh_session->num_newcoins;j++)
{
if (NULL == ev_sigs[j].rsa_signature) /* could be non-NULL during retries */
ev_sigs[j] = refresh_exchange_coin (connection,
session,
session_hash,
key_state,
&denom_pubs[j],
&commit_coins[j],
j);
if (NULL == ev_sigs[j].rsa_signature)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
ret = TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_SIGNING_ERROR);
goto cleanup;
}
}
COMMIT_TRANSACTION (session, connection);
ret = TEH_RESPONSE_reply_refresh_reveal_success (connection,
refresh_session->num_newcoins,
ev_sigs);
cleanup:
TEH_KS_release (key_state);
return ret;
}
/**
* Execute a "/refresh/reveal". The client is revealing to us the
* transfer keys for @a #TALER_CNC_KAPPA-1 sets of coins. Verify that the
* revealed transfer keys would allow linkage to the blinded coins,
* and if so, return the signed coins for corresponding to the set of
* coins that was not chosen.
*
* @param connection the MHD connection to handle
* @param session_hash hash identifying the refresh session
* @param transfer_privs array with the revealed transfer keys,
* length must be #TALER_CNC_KAPPA - 1
* @return MHD result code
*/
int
TEH_DB_execute_refresh_reveal (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
struct TALER_TransferPrivateKeyP *transfer_privs)
{
int res;
struct TALER_EXCHANGEDB_Session *session;
struct TALER_EXCHANGEDB_RefreshSession refresh_session;
struct TALER_DenominationPublicKey *denom_pubs;
struct TALER_DenominationSignature *ev_sigs;
struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins;
unsigned int i;
unsigned int j;
unsigned int off;
struct GNUNET_HashContext *hash_context;
struct GNUNET_HashCode sh_check;
int ret;
struct TALER_TransferPublicKeyP gamma_tp;
if (NULL == (session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
res = TEH_plugin->get_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session);
if (GNUNET_NO == res)
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_REFRESH_REVEAL_SESSION_UNKNOWN,
"session_hash");
if ( (GNUNET_SYSERR == res) ||
(refresh_session.noreveal_index >= TALER_CNC_KAPPA) )
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_SESSION_ERROR);
denom_pubs = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_DenominationPublicKey);
if (GNUNET_OK !=
TEH_plugin->get_refresh_order (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
denom_pubs))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_ORDER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
hash_context = GNUNET_CRYPTO_hash_context_start ();
/* first, iterate over transfer public keys for hash_context */
off = 0;
for (i=0;i<TALER_CNC_KAPPA;i++)
{
if (i == refresh_session.noreveal_index)
{
off = 1;
/* obtain gamma_tp from db */
if (GNUNET_OK !=
TEH_plugin->get_refresh_transfer_public_key (TEH_plugin->cls,
session,
session_hash,
&gamma_tp))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_TRANSFER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
GNUNET_CRYPTO_hash_context_read (hash_context,
&gamma_tp,
sizeof (struct TALER_TransferPublicKeyP));
}
else
{
/* compute tp from private key */
struct TALER_TransferPublicKeyP tp;
GNUNET_CRYPTO_ecdhe_key_get_public (&transfer_privs[i - off].ecdhe_priv,
&tp.ecdhe_pub);
GNUNET_CRYPTO_hash_context_read (hash_context,
&tp,
sizeof (struct TALER_TransferPublicKeyP));
}
}
/* next, add all of the hashes from the denomination keys to the
hash_context */
{
struct TALER_DenominationPublicKey denom_pubs[refresh_session.num_newcoins];
if (GNUNET_OK !=
TEH_plugin->get_refresh_order (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
denom_pubs))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_ORDER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
for (i=0;i<refresh_session.num_newcoins;i++)
{
char *buf;
size_t buf_size;
buf_size = GNUNET_CRYPTO_rsa_public_key_encode (denom_pubs[i].rsa_public_key,
&buf);
GNUNET_CRYPTO_hash_context_read (hash_context,
buf,
buf_size);
GNUNET_free (buf);
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[i].rsa_public_key);
}
}
/* next, add public key of coin and amount being refreshed */
{
struct TALER_AmountNBO melt_amountn;
GNUNET_CRYPTO_hash_context_read (hash_context,
&refresh_session.melt.coin.coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP));
TALER_amount_hton (&melt_amountn,
&refresh_session.melt.amount_with_fee);
GNUNET_CRYPTO_hash_context_read (hash_context,
&melt_amountn,
sizeof (struct TALER_AmountNBO));
}
commit_coins = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_EXCHANGEDB_RefreshCommitCoin);
off = 0;
for (i=0;i<TALER_CNC_KAPPA;i++)
{
if (i == refresh_session.noreveal_index)
{
off = 1;
/* obtain commit_coins for the selected gamma value from DB */
if (GNUNET_OK !=
TEH_plugin->get_refresh_commit_coins (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
commit_coins))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_COMMIT_ERROR);
}
/* add envelopes to hash_context */
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_CRYPTO_hash_context_read (hash_context,
commit_coins[j].coin_ev,
commit_coins[j].coin_ev_size);
}
continue;
}
if (GNUNET_OK !=
(res = check_commitment (connection,
session,
session_hash,
i,
&transfer_privs[i - off],
&refresh_session.melt,
refresh_session.num_newcoins,
denom_pubs,
hash_context)))
{
GNUNET_break_op (0);
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
GNUNET_free (commit_coins[j].coin_ev);
}
GNUNET_free (commit_coins);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
}
}
/* Check session hash matches */
GNUNET_CRYPTO_hash_context_finish (hash_context,
&sh_check);
if (0 != memcmp (&sh_check,
session_hash,
sizeof (struct GNUNET_HashCode)))
{
GNUNET_break_op (0);
ret = TEH_RESPONSE_reply_refresh_reveal_missmatch (connection,
&refresh_session,
commit_coins,
denom_pubs,
&gamma_tp);
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_free (commit_coins[j].coin_ev);
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
}
GNUNET_free (commit_coins);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
return ret;
}
/* Client request OK, start transaction */
ev_sigs = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_DenominationSignature);
/* FIXME: might need to store revealed transfer private keys for
the auditor for later; should pass them as arguments here! #4792*/
res = execute_refresh_reveal_transaction (connection,
session,
session_hash,
&refresh_session,
denom_pubs,
ev_sigs,
commit_coins);
for (i=0;i<refresh_session.num_newcoins;i++)
{
if (NULL != ev_sigs[i].rsa_signature)
GNUNET_CRYPTO_rsa_signature_free (ev_sigs[i].rsa_signature);
GNUNET_free (commit_coins[i].coin_ev);
}
for (j=0;j<refresh_session.num_newcoins;j++)
if (NULL != denom_pubs[j].rsa_public_key)
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_free (ev_sigs);
GNUNET_free (denom_pubs);
GNUNET_free (commit_coins);
return res;
}
/**
* Closure for #handle_transfer_data().
*/
struct HTD_Context
{
/**
* Session link data we collect.
*/
struct TEH_RESPONSE_LinkSessionInfo *sessions;
/**
* Database session. Nothing to do with @a sessions.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* MHD connection, for queueing replies.
*/
struct MHD_Connection *connection;
/**
* Number of sessions the coin was melted into.
*/
unsigned int num_sessions;
/**
* How are we expected to proceed. #GNUNET_SYSERR if we
* failed to return an error (should return #MHD_NO).
* #GNUNET_NO if we succeeded in queueing an MHD error
* (should return #MHD_YES from #TEH_execute_refresh_link),
* #GNUNET_OK if we should call #TEH_RESPONSE_reply_refresh_link_success().
*/
int status;
};
/**
* Function called with the session hashes and transfer secret
* information for a given coin. Gets the linkage data and
* builds the reply for the client.
*
*
* @param cls closure, a `struct HTD_Context`
* @param session_hash a session the coin was melted in
* @param transfer_pub public transfer key for the session
*/
static void
handle_transfer_data (void *cls,
const struct GNUNET_HashCode *session_hash,
const struct TALER_TransferPublicKeyP *transfer_pub)
{
struct HTD_Context *ctx = cls;
struct TALER_EXCHANGEDB_LinkDataList *ldl;
struct TEH_RESPONSE_LinkSessionInfo *lsi;
if (GNUNET_OK != ctx->status)
return;
ldl = TEH_plugin->get_link_data_list (TEH_plugin->cls,
ctx->session,
session_hash);
if (NULL == ldl)
{
ctx->status = GNUNET_NO;
if (MHD_NO ==
TEH_RESPONSE_reply_json_pack (ctx->connection,
MHD_HTTP_NOT_FOUND,
"{s:s}",
"error",
"link data not found (link)"))
ctx->status = GNUNET_SYSERR;
return;
}
GNUNET_array_grow (ctx->sessions,
ctx->num_sessions,
ctx->num_sessions + 1);
lsi = &ctx->sessions[ctx->num_sessions - 1];
lsi->transfer_pub = *transfer_pub;
lsi->ldl = ldl;
}
/**
* Execute a "/refresh/link". Returns the linkage information that
* will allow the owner of a coin to follow the refresh trail to
* the refreshed coin.
*
* @param connection the MHD connection to handle
* @param coin_pub public key of the coin to link
* @return MHD result code
*/
int
TEH_DB_execute_refresh_link (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub)
{
struct HTD_Context ctx;
int res;
unsigned int i;
if (NULL == (ctx.session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
ctx.connection = connection;
ctx.num_sessions = 0;
ctx.sessions = NULL;
ctx.status = GNUNET_OK;
res = TEH_plugin->get_transfer (TEH_plugin->cls,
ctx.session,
coin_pub,
&handle_transfer_data,
&ctx);
if (GNUNET_SYSERR == ctx.status)
{
res = MHD_NO;
goto cleanup;
}
if (GNUNET_NO == ctx.status)
{
res = MHD_YES;
goto cleanup;
}
GNUNET_assert (GNUNET_OK == ctx.status);
if (0 == ctx.num_sessions)
return TEH_RESPONSE_reply_arg_unknown (connection,
TALER_EC_REFRESH_LINK_COIN_UNKNOWN,
"coin_pub");
res = TEH_RESPONSE_reply_refresh_link_success (connection,
ctx.num_sessions,
ctx.sessions);
cleanup:
for (i=0;i<ctx.num_sessions;i++)
TEH_plugin->free_link_data_list (TEH_plugin->cls,
ctx.sessions[i].ldl);
GNUNET_free_non_null (ctx.sessions);
return res;
}
/* end of taler-exchange-httpd_db.c */ /* end of taler-exchange-httpd_db.c */

View File

@ -1,6 +1,6 @@
/* /*
This file is part of TALER This file is part of TALER
Copyright (C) 2014, 2015 GNUnet e.V. Copyright (C) 2014-2017 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the 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 terms of the GNU General Public License as published by the Free Software
@ -83,97 +83,5 @@ TEH_DB_calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionLis
struct TALER_Amount *ret); struct TALER_Amount *ret);
/**
* @brief Details about a melt operation of an individual coin.
*/
struct TEH_DB_MeltDetails
{
/**
* Information about the coin being melted.
*/
struct TALER_CoinPublicInfo coin_info;
/**
* Signature allowing the melt (using
* a `struct TALER_EXCHANGEDB_RefreshMeltConfirmSignRequestBody`) to sign over.
*/
struct TALER_CoinSpendSignatureP melt_sig;
/**
* How much of the coin's value did the client allow to be melted?
* This amount includes the fees, so the final amount contributed
* to the melt is this value minus the fee for melting the coin.
*/
struct TALER_Amount melt_amount_with_fee;
/**
* What fee is earned by the exchange? Set delayed during
* #verify_coin_public_info().
*/
struct TALER_Amount melt_fee;
};
/**
* Execute a "/refresh/melt". We have been given a list of valid
* coins and a request to melt them into the given
* @a refresh_session_pub. Check that the coins all have the
* required value left and if so, store that they have been
* melted and confirm the melting operation to the client.
*
* @param connection the MHD connection to handle
* @param session_hash hash code of the session the coins are melted into
* @param num_new_denoms number of entries in @a denom_pubs, size of y-dimension of @a commit_coin array
* @param denom_pubs array of public denomination keys for the refresh (?)
* @param coin_melt_detail signatures and (residual) value of and information about the respective coin to be melted
* @param commit_coin 2d array of coin commitments (what the exchange is to sign
* once the "/refres/reveal" of cut and choose is done)
* @param transfer_pubs array of transfer public keys (what the exchange is
* to return via "/refresh/link" to enable linkage in the
* future) of length #TALER_CNC_KAPPA
* @return MHD result code
*/
int
TEH_DB_execute_refresh_melt (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
unsigned int num_new_denoms,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TEH_DB_MeltDetails *coin_melt_detail,
struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
const struct TALER_TransferPublicKeyP *transfer_pubs);
/**
* Execute a "/refresh/reveal". The client is revealing to us the
* transfer keys for #TALER_CNC_KAPPA-1 sets of coins. Verify that the
* revealed transfer keys would allow linkage to the blinded coins,
* and if so, return the signed coins for corresponding to the set of
* coins that was not chosen.
*
* @param connection the MHD connection to handle
* @param session_hash hash over the refresh session
* @param transfer_privs array of length #TALER_CNC_KAPPA-1 with the revealed transfer keys
* @return MHD result code
*/
int
TEH_DB_execute_refresh_reveal (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
struct TALER_TransferPrivateKeyP *transfer_privs);
/**
* Execute a "/refresh/link". Returns the linkage information that
* will allow the owner of a coin to follow the refresh trail to the
* refreshed coin.
*
* @param connection the MHD connection to handle
* @param coin_pub public key of the coin to link
* @return MHD result code
*/
int
TEH_DB_execute_refresh_link (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub);
#endif #endif
/* TALER_EXCHANGE_HTTPD_DB_H */ /* TALER_EXCHANGE_HTTPD_DB_H */

View File

@ -0,0 +1,286 @@
/*
This file is part of TALER
Copyright (C) 2014-2017 Inria & GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-exchange-httpd_refresh_link.c
* @brief Handle /refresh/link requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <jansson.h>
#include <microhttpd.h>
#include "taler-exchange-httpd_parsing.h"
#include "taler-exchange-httpd_mhd.h"
#include "taler-exchange-httpd_refresh_link.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.h"
/**
* @brief Information for each session a coin was melted into.
*/
struct TEH_RESPONSE_LinkSessionInfo
{
/**
* Transfer public key of the coin.
*/
struct TALER_TransferPublicKeyP transfer_pub;
/**
* Linked data of coins being created in the session.
*/
struct TALER_EXCHANGEDB_LinkDataList *ldl;
};
/**
* Closure for #handle_transfer_data().
*/
struct HTD_Context
{
/**
* Session link data we collect.
*/
struct TEH_RESPONSE_LinkSessionInfo *sessions;
/**
* Database session. Nothing to do with @a sessions.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* MHD connection, for queueing replies.
*/
struct MHD_Connection *connection;
/**
* Number of sessions the coin was melted into.
*/
unsigned int num_sessions;
/**
* How are we expected to proceed. #GNUNET_SYSERR if we
* failed to return an error (should return #MHD_NO).
* #GNUNET_NO if we succeeded in queueing an MHD error
* (should return #MHD_YES from #TEH_execute_refresh_link),
* #GNUNET_OK if we should call #reply_refresh_link_success().
*/
int status;
};
/**
* Send a response for "/refresh/link".
*
* @param connection the connection to send the response to
* @param num_sessions number of sessions the coin was used in
* @param sessions array of @a num_session entries with
* information for each session
* @return a MHD result code
*/
static int
reply_refresh_link_success (struct MHD_Connection *connection,
unsigned int num_sessions,
const struct TEH_RESPONSE_LinkSessionInfo *sessions)
{
json_t *root;
json_t *mlist;
int res;
unsigned int i;
mlist = json_array ();
for (i=0;i<num_sessions;i++)
{
const struct TALER_EXCHANGEDB_LinkDataList *pos;
json_t *list = json_array ();
for (pos = sessions[i].ldl; NULL != pos; pos = pos->next)
{
json_t *obj;
obj = json_object ();
json_object_set_new (obj,
"denom_pub",
GNUNET_JSON_from_rsa_public_key (pos->denom_pub.rsa_public_key));
json_object_set_new (obj,
"ev_sig",
GNUNET_JSON_from_rsa_signature (pos->ev_sig.rsa_signature));
GNUNET_assert (0 ==
json_array_append_new (list,
obj));
}
root = json_object ();
json_object_set_new (root,
"new_coins",
list);
json_object_set_new (root,
"transfer_pub",
GNUNET_JSON_from_data_auto (&sessions[i].transfer_pub));
GNUNET_assert (0 ==
json_array_append_new (mlist,
root));
}
res = TEH_RESPONSE_reply_json (connection,
mlist,
MHD_HTTP_OK);
json_decref (mlist);
return res;
}
/**
* Function called with the session hashes and transfer secret
* information for a given coin. Gets the linkage data and
* builds the reply for the client.
*
*
* @param cls closure, a `struct HTD_Context`
* @param session_hash a session the coin was melted in
* @param transfer_pub public transfer key for the session
*/
static void
handle_transfer_data (void *cls,
const struct GNUNET_HashCode *session_hash,
const struct TALER_TransferPublicKeyP *transfer_pub)
{
struct HTD_Context *ctx = cls;
struct TALER_EXCHANGEDB_LinkDataList *ldl;
struct TEH_RESPONSE_LinkSessionInfo *lsi;
if (GNUNET_OK != ctx->status)
return;
ldl = TEH_plugin->get_link_data_list (TEH_plugin->cls,
ctx->session,
session_hash);
if (NULL == ldl)
{
ctx->status = GNUNET_NO;
if (MHD_NO ==
TEH_RESPONSE_reply_json_pack (ctx->connection,
MHD_HTTP_NOT_FOUND,
"{s:s}",
"error",
"link data not found (link)"))
ctx->status = GNUNET_SYSERR;
return;
}
GNUNET_array_grow (ctx->sessions,
ctx->num_sessions,
ctx->num_sessions + 1);
lsi = &ctx->sessions[ctx->num_sessions - 1];
lsi->transfer_pub = *transfer_pub;
lsi->ldl = ldl;
}
/**
* Execute a "/refresh/link". Returns the linkage information that
* will allow the owner of a coin to follow the refresh trail to
* the refreshed coin.
*
* @param connection the MHD connection to handle
* @param coin_pub public key of the coin to link
* @return MHD result code
*/
static int
execute_refresh_link (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub)
{
struct HTD_Context ctx;
int res;
unsigned int i;
if (NULL == (ctx.session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
ctx.connection = connection;
ctx.num_sessions = 0;
ctx.sessions = NULL;
ctx.status = GNUNET_OK;
res = TEH_plugin->get_transfer (TEH_plugin->cls,
ctx.session,
coin_pub,
&handle_transfer_data,
&ctx);
if (GNUNET_SYSERR == ctx.status)
{
res = MHD_NO;
goto cleanup;
}
if (GNUNET_NO == ctx.status)
{
res = MHD_YES;
goto cleanup;
}
GNUNET_assert (GNUNET_OK == ctx.status);
if (0 == ctx.num_sessions)
return TEH_RESPONSE_reply_arg_unknown (connection,
TALER_EC_REFRESH_LINK_COIN_UNKNOWN,
"coin_pub");
res = reply_refresh_link_success (connection,
ctx.num_sessions,
ctx.sessions);
cleanup:
for (i=0;i<ctx.num_sessions;i++)
TEH_plugin->free_link_data_list (TEH_plugin->cls,
ctx.sessions[i].ldl);
GNUNET_free_non_null (ctx.sessions);
return res;
}
/**
* Handle a "/refresh/link" request. Note that for "/refresh/link"
* we do use a simple HTTP GET, and a HTTP POST!
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
struct TALER_CoinSpendPublicKeyP coin_pub;
int res;
res = TEH_PARSE_mhd_request_arg_data (connection,
"coin_pub",
&coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP));
if (GNUNET_SYSERR == res)
return MHD_NO;
if (GNUNET_OK != res)
return MHD_YES;
return execute_refresh_link (connection,
&coin_pub);
}
/* end of taler-exchange-httpd_refresh_link.c */

View File

@ -0,0 +1,49 @@
/*
This file is part of TALER
Copyright (C) 2014-2017 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-exchange-httpd_refresh_link.h
* @brief Handle /refresh/link requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#ifndef TALER_EXCHANGE_HTTPD_REFRESH_LINK_H
#define TALER_EXCHANGE_HTTPD_REFRESH_LINK_H
#include <gnunet/gnunet_util_lib.h>
#include <microhttpd.h>
#include "taler-exchange-httpd.h"
/**
* Handle a "/refresh/link" request
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size);
#endif

View File

@ -1,6 +1,6 @@
/* /*
This file is part of TALER This file is part of TALER
Copyright (C) 2014, 2015, 2016 Inria & GNUnet e.V. Copyright (C) 2014-2017 Inria & GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software terms of the GNU Affero General Public License as published by the Free Software
@ -14,8 +14,8 @@
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/ */
/** /**
* @file taler-exchange-httpd_refresh.c * @file taler-exchange-httpd_refresh_melt.c
* @brief Handle /refresh/ requests * @brief Handle /refresh/melt requests
* @author Florian Dold * @author Florian Dold
* @author Benedikt Mueller * @author Benedikt Mueller
* @author Christian Grothoff * @author Christian Grothoff
@ -26,11 +26,454 @@
#include <microhttpd.h> #include <microhttpd.h>
#include "taler-exchange-httpd_parsing.h" #include "taler-exchange-httpd_parsing.h"
#include "taler-exchange-httpd_mhd.h" #include "taler-exchange-httpd_mhd.h"
#include "taler-exchange-httpd_refresh.h" #include "taler-exchange-httpd_refresh_melt.h"
#include "taler-exchange-httpd_responses.h" #include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.h" #include "taler-exchange-httpd_keystate.h"
/**
* How often should we retry a transaction before giving up
* (for transactions resulting in serialization/dead locks only).
*/
#define MAX_TRANSACTION_COMMIT_RETRIES 3
/**
* Code to begin a transaction, must be inline as we define a block
* that ends with #COMMIT_TRANSACTION() within which we perform a number
* of retries. Note that this code may call "return" internally, so
* it must be called within a function where any cleanup will be done
* by the caller. Furthermore, the function's return value must
* match that of a #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define START_TRANSACTION(session,connection) \
{ /* start new scope, will be ended by COMMIT_TRANSACTION() */\
unsigned int transaction_retries = 0; \
enum GNUNET_DB_QueryStatus transaction_commit_result; \
transaction_start_label: /* we will use goto for retries */ \
if (GNUNET_OK != \
TEH_plugin->start (TEH_plugin->cls, \
session)) \
{ \
GNUNET_break (0); \
return TEH_RESPONSE_reply_internal_db_error (connection, \
TALER_EC_DB_START_FAILED); \
}
/**
* Code to conclude a transaction, dual to #START_TRANSACTION(). Note
* that this code may call "return" internally, so it must be called
* within a function where any cleanup will be done by the caller.
* Furthermore, the function's return value must match that of a
* #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define COMMIT_TRANSACTION(session,connection) \
transaction_commit_result = \
TEH_plugin->commit (TEH_plugin->cls, \
session); \
if (GNUNET_DB_STATUS_HARD_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_HARD); \
} \
if (GNUNET_DB_STATUS_SOFT_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} \
} /* end of scope opened by BEGIN_TRANSACTION */
/**
* Code to include to retry a transaction, must only be used in between
* #START_TRANSACTION and #COMMIT_TRANSACTION.
*
* @param session session handle
* @param connection connection handle
*/
#define RETRY_TRANSACTION(session,connection) \
do { \
TEH_plugin->rollback (TEH_plugin->cls, \
session); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} while (0)
/**
* @brief Details about a melt operation of an individual coin.
*/
struct TEH_DB_MeltDetails
{
/**
* Information about the coin being melted.
*/
struct TALER_CoinPublicInfo coin_info;
/**
* Signature allowing the melt (using
* a `struct TALER_EXCHANGEDB_RefreshMeltConfirmSignRequestBody`) to sign over.
*/
struct TALER_CoinSpendSignatureP melt_sig;
/**
* How much of the coin's value did the client allow to be melted?
* This amount includes the fees, so the final amount contributed
* to the melt is this value minus the fee for melting the coin.
*/
struct TALER_Amount melt_amount_with_fee;
/**
* What fee is earned by the exchange? Set delayed during
* #verify_coin_public_info().
*/
struct TALER_Amount melt_fee;
};
/**
* Send a response for a failed "/refresh/melt" request. The
* transaction history of the given coin demonstrates that the
* @a residual value of the coin is below the @a requested
* contribution of the coin for the melt. Thus, the exchange
* refuses the melt operation.
*
* @param connection the connection to send the response to
* @param coin_pub public key of the coin
* @param coin_value original value of the coin
* @param tl transaction history for the coin
* @param requested how much this coin was supposed to contribute, including fee
* @param residual remaining value of the coin (after subtracting @a tl)
* @return a MHD result code
*/
static int
reply_refresh_melt_insufficient_funds (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_Amount coin_value,
struct TALER_EXCHANGEDB_TransactionList *tl,
struct TALER_Amount requested,
struct TALER_Amount residual)
{
json_t *history;
history = TEH_RESPONSE_compile_transaction_history (tl);
if (NULL == history)
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS);
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_FORBIDDEN,
"{s:s, s:I, s:o, s:o, s:o, s:o, s:o}",
"error",
"insufficient funds",
"code",
(json_int_t) TALER_EC_REFRESH_MELT_INSUFFICIENT_FUNDS,
"coin_pub",
GNUNET_JSON_from_data_auto (coin_pub),
"original_value",
TALER_JSON_from_amount (&coin_value),
"residual_value",
TALER_JSON_from_amount (&residual),
"requested_value",
TALER_JSON_from_amount (&requested),
"history",
history);
}
/**
* Send a response to a "/refresh/melt" request.
*
* @param connection the connection to send the response to
* @param session_hash hash of the refresh session
* @param noreveal_index which index will the client not have to reveal
* @return a MHD status code
*/
static int
reply_refresh_melt_success (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
uint16_t noreveal_index)
{
struct TALER_RefreshMeltConfirmationPS body;
struct TALER_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
json_t *sig_json;
body.purpose.size = htonl (sizeof (struct TALER_RefreshMeltConfirmationPS));
body.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_MELT);
body.session_hash = *session_hash;
body.noreveal_index = htons (noreveal_index);
body.reserved = htons (0);
TEH_KS_sign (&body.purpose,
&pub,
&sig);
sig_json = GNUNET_JSON_from_data_auto (&sig);
GNUNET_assert (NULL != sig_json);
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:i, s:o, s:o}",
"noreveal_index", (int) noreveal_index,
"exchange_sig", sig_json,
"exchange_pub", GNUNET_JSON_from_data_auto (&pub));
}
/**
* Parse coin melt requests from a JSON object and write them to
* the database.
*
* @param connection the connection to send errors to
* @param session the database connection
* @param key_state the exchange's key state
* @param session_hash hash identifying the refresh session
* @param coin_details details about the coin being melted
* @param[out] meltp on success, set to melt details
* @return #GNUNET_OK on success,
* #GNUNET_NO if an error message was generated,
* #GNUNET_SYSERR on internal errors (no response generated)
*/
static int
refresh_check_melt (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct TEH_KS_StateHandle *key_state,
const struct GNUNET_HashCode *session_hash,
const struct TEH_DB_MeltDetails *coin_details,
struct TALER_EXCHANGEDB_RefreshMelt *meltp)
{
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dk;
struct TALER_EXCHANGEDB_DenominationKeyInformationP *dki;
struct TALER_EXCHANGEDB_TransactionList *tl;
struct TALER_Amount coin_value;
struct TALER_Amount coin_residual;
struct TALER_Amount spent;
int res;
enum GNUNET_DB_QueryStatus qs;
dk = TEH_KS_denomination_key_lookup (key_state,
&coin_details->coin_info.denom_pub,
TEH_KS_DKU_DEPOSIT);
if (NULL == dk)
return (MHD_YES ==
TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_REFRESH_MELT_DB_DENOMINATION_KEY_NOT_FOUND,
"denomination key no longer available while executing transaction"))
? GNUNET_NO : GNUNET_SYSERR;
dki = &dk->issue;
TALER_amount_ntoh (&coin_value,
&dki->properties.value);
/* fee for THIS transaction; the melt amount includes the fee! */
spent = coin_details->melt_amount_with_fee;
/* add historic transaction costs of this coin */
qs = TEH_plugin->get_coin_transactions (TEH_plugin->cls,
session,
&coin_details->coin_info.coin_pub,
&tl);
(void) qs; /* FIXME #5010 */
if (GNUNET_OK !=
TEH_DB_calculate_transaction_list_totals (tl,
&spent,
&spent))
{
GNUNET_break (0);
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
return (MHD_YES ==
TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_COIN_HISTORY_COMPUTATION_FAILED))
? GNUNET_NO : GNUNET_SYSERR;
}
/* Refuse to refresh when the coin's value is insufficient
for the cost of all transactions. */
if (TALER_amount_cmp (&coin_value,
&spent) < 0)
{
GNUNET_assert (GNUNET_SYSERR !=
TALER_amount_subtract (&coin_residual,
&spent,
&coin_details->melt_amount_with_fee));
res = (MHD_YES ==
reply_refresh_melt_insufficient_funds (connection,
&coin_details->coin_info.coin_pub,
coin_value,
tl,
coin_details->melt_amount_with_fee,
coin_residual))
? GNUNET_NO : GNUNET_SYSERR;
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
return res;
}
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
meltp->coin = coin_details->coin_info;
meltp->coin_sig = coin_details->melt_sig;
meltp->session_hash = *session_hash;
meltp->amount_with_fee = coin_details->melt_amount_with_fee;
meltp->melt_fee = coin_details->melt_fee;
return GNUNET_OK;
}
/**
* Execute a "/refresh/melt". We have been given a list of valid
* coins and a request to melt them into the given
* @a refresh_session_pub. Check that the coins all have the
* required value left and if so, store that they have been
* melted and confirm the melting operation to the client.
*
* @param connection the MHD connection to handle
* @param session_hash hash code of the session the coins are melted into
* @param num_new_denoms number of entries in @a denom_pubs, size of y-dimension of @a commit_coin array
* @param denom_pubs public keys of the coins we want to withdraw in the end
* @param coin_melt_detail signature and (residual) value of the respective coin should be melted
* @param commit_coin 2d array of coin commitments (what the exchange is to sign
* once the "/refres/reveal" of cut and choose is done),
* x-dimension must be #TALER_CNC_KAPPA
* @param transfer_pubs array of transfer public keys (what the exchange is
* to return via "/refresh/link" to enable linkage in the
* future) of length #TALER_CNC_KAPPA
* @return MHD result code
*/
static int
execute_refresh_melt (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
unsigned int num_new_denoms,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TEH_DB_MeltDetails *coin_melt_detail,
struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
const struct TALER_TransferPublicKeyP *transfer_pubs)
{
struct TEH_KS_StateHandle *key_state;
struct TALER_EXCHANGEDB_RefreshSession refresh_session;
struct TALER_EXCHANGEDB_Session *session;
int res;
if (NULL == (session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
START_TRANSACTION (session, connection);
res = TEH_plugin->get_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session);
if (GNUNET_YES == res)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
res = reply_refresh_melt_success (connection,
session_hash,
refresh_session.noreveal_index);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
if (GNUNET_SYSERR == res)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_FETCH_ERROR);
}
/* store 'global' session data */
refresh_session.num_newcoins = num_new_denoms;
refresh_session.noreveal_index
= GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG,
TALER_CNC_KAPPA);
key_state = TEH_KS_acquire ();
if (GNUNET_OK !=
(res = refresh_check_melt (connection,
session,
key_state,
session_hash,
coin_melt_detail,
&refresh_session.melt)))
{
TEH_KS_release (key_state);
TEH_plugin->rollback (TEH_plugin->cls,
session);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
TEH_KS_release (key_state);
if (GNUNET_OK !=
(res = TEH_plugin->create_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session)))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_SESSION_ERROR);
}
/* store requested new denominations */
if (GNUNET_OK !=
TEH_plugin->insert_refresh_order (TEH_plugin->cls,
session,
session_hash,
num_new_denoms,
denom_pubs))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_ORDER_ERROR);
}
if (GNUNET_OK !=
TEH_plugin->insert_refresh_commit_coins (TEH_plugin->cls,
session,
session_hash,
num_new_denoms,
commit_coin[refresh_session.noreveal_index]))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_ORDER_ERROR);
}
if (GNUNET_OK !=
TEH_plugin->insert_refresh_transfer_public_key (TEH_plugin->cls,
session,
session_hash,
&transfer_pubs[refresh_session.noreveal_index]))
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_DB_STORE_TRANSFER_ERROR);
}
COMMIT_TRANSACTION (session, connection);
return reply_refresh_melt_success (connection,
session_hash,
refresh_session.noreveal_index);
}
/** /**
* Handle a "/refresh/melt" request after the main JSON parsing has happened. * Handle a "/refresh/melt" request after the main JSON parsing has happened.
* We now need to validate the coins being melted and the session signature * We now need to validate the coins being melted and the session signature
@ -149,7 +592,7 @@ handle_refresh_melt_binary (struct MHD_Connection *connection,
"error", "value mismatch", "error", "value mismatch",
"code", (json_int_t) TALER_EC_REFRESH_MELT_FEES_MISSMATCH); "code", (json_int_t) TALER_EC_REFRESH_MELT_FEES_MISSMATCH);
} }
return TEH_DB_execute_refresh_melt (connection, return execute_refresh_melt (connection,
session_hash, session_hash,
num_new_denoms, num_new_denoms,
denom_pubs, denom_pubs,
@ -597,159 +1040,4 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
} }
/** /* end of taler-exchange-httpd_refresh_melt.c */
* Handle a "/refresh/reveal" request. Parses the given JSON
* transfer private keys and if successful, passes everything to
* #TEH_DB_execute_refresh_reveal() which will verify that the
* revealed information is valid then returns the signed refreshed
* coins.
*
* @param connection the MHD connection to handle
* @param session_hash hash identifying the melting session
* @param tp_json private transfer keys in JSON format
* @return MHD result code
*/
static int
handle_refresh_reveal_json (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
const json_t *tp_json)
{
struct TALER_TransferPrivateKeyP transfer_privs[TALER_CNC_KAPPA - 1];
unsigned int i;
int res;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"reveal request for session %s\n",
GNUNET_h2s (session_hash));
res = GNUNET_OK;
for (i = 0; i < TALER_CNC_KAPPA - 1; i++)
{
struct GNUNET_JSON_Specification tp_spec[] = {
GNUNET_JSON_spec_fixed_auto (NULL, &transfer_privs[i]),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK != res)
break;
res = TEH_PARSE_json_array (connection,
tp_json,
tp_spec,
i, -1);
GNUNET_break_op (GNUNET_OK == res);
}
if (GNUNET_OK != res)
res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
else
res = TEH_DB_execute_refresh_reveal (connection,
session_hash,
transfer_privs);
return res;
}
/**
* Handle a "/refresh/reveal" request. This time, the client reveals
* the private transfer keys except for the cut-and-choose value
* returned from "/refresh/melt". This function parses the revealed
* keys and secrets and ultimately passes everything to
* #TEH_DB_execute_refresh_reveal() which will verify that the
* revealed information is valid then returns the signed refreshed
* coins.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_reveal (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
struct GNUNET_HashCode session_hash;
int res;
json_t *root;
json_t *transfer_privs;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("session_hash", &session_hash),
GNUNET_JSON_spec_json ("transfer_privs", &transfer_privs),
GNUNET_JSON_spec_end ()
};
res = TEH_PARSE_post_json (connection,
connection_cls,
upload_data,
upload_data_size,
&root);
if (GNUNET_SYSERR == res)
return MHD_NO;
if ( (GNUNET_NO == res) || (NULL == root) )
return MHD_YES;
res = TEH_PARSE_json_data (connection,
root,
spec);
json_decref (root);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
/* Determine dimensionality of the request (kappa and #old coins) */
/* Note we do +1 as 1 row (cut-and-choose!) is missing! */
if (TALER_CNC_KAPPA != json_array_size (transfer_privs) + 1)
{
GNUNET_JSON_parse_free (spec);
GNUNET_break_op (0);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_REFRESH_REVEAL_CNC_TRANSFER_ARRAY_SIZE_INVALID,
"transfer_privs");
}
res = handle_refresh_reveal_json (connection,
&session_hash,
transfer_privs);
GNUNET_JSON_parse_free (spec);
return res;
}
/**
* Handle a "/refresh/link" request. Note that for "/refresh/link"
* we do use a simple HTTP GET, and a HTTP POST!
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
struct TALER_CoinSpendPublicKeyP coin_pub;
int res;
res = TEH_PARSE_mhd_request_arg_data (connection,
"coin_pub",
&coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP));
if (GNUNET_SYSERR == res)
return MHD_NO;
if (GNUNET_OK != res)
return MHD_YES;
return TEH_DB_execute_refresh_link (connection,
&coin_pub);
}
/* end of taler-exchange-httpd_refresh.c */

View File

@ -0,0 +1,52 @@
/*
This file is part of TALER
Copyright (C) 2014-2017 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-exchange-httpd_refresh_melt.h
* @brief Handle /refresh/melt requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#ifndef TALER_EXCHANGE_HTTPD_REFRESH_MELT_H
#define TALER_EXCHANGE_HTTPD_REFRESH_MELT_H
#include <gnunet/gnunet_util_lib.h>
#include <microhttpd.h>
#include "taler-exchange-httpd.h"
/**
* Handle a "/refresh/melt" request. Parses the request into the JSON
* components and then hands things of to #handle_refresh_melt_json()
* to validate the melted coins, the signature and execute the melt
* using TEH_DB_execute_refresh_melt().
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size);
#endif

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@ -0,0 +1,833 @@
/*
This file is part of TALER
Copyright (C) 2014-2017 Inria & GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-exchange-httpd_refresh_reveal.c
* @brief Handle /refresh/reveal requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <jansson.h>
#include <microhttpd.h>
#include "taler-exchange-httpd_parsing.h"
#include "taler-exchange-httpd_mhd.h"
#include "taler-exchange-httpd_refresh_reveal.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.h"
/**
* How often should we retry a transaction before giving up
* (for transactions resulting in serialization/dead locks only).
*/
#define MAX_TRANSACTION_COMMIT_RETRIES 3
/**
* Code to begin a transaction, must be inline as we define a block
* that ends with #COMMIT_TRANSACTION() within which we perform a number
* of retries. Note that this code may call "return" internally, so
* it must be called within a function where any cleanup will be done
* by the caller. Furthermore, the function's return value must
* match that of a #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define START_TRANSACTION(session,connection) \
{ /* start new scope, will be ended by COMMIT_TRANSACTION() */\
unsigned int transaction_retries = 0; \
enum GNUNET_DB_QueryStatus transaction_commit_result; \
transaction_start_label: /* we will use goto for retries */ \
if (GNUNET_OK != \
TEH_plugin->start (TEH_plugin->cls, \
session)) \
{ \
GNUNET_break (0); \
return TEH_RESPONSE_reply_internal_db_error (connection, \
TALER_EC_DB_START_FAILED); \
}
/**
* Code to conclude a transaction, dual to #START_TRANSACTION(). Note
* that this code may call "return" internally, so it must be called
* within a function where any cleanup will be done by the caller.
* Furthermore, the function's return value must match that of a
* #TEH_RESPONSE_reply_internal_db_error() status code.
*
* @param session session handle
* @param connection connection handle
*/
#define COMMIT_TRANSACTION(session,connection) \
transaction_commit_result = \
TEH_plugin->commit (TEH_plugin->cls, \
session); \
if (GNUNET_DB_STATUS_HARD_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_HARD); \
} \
if (GNUNET_DB_STATUS_SOFT_ERROR == transaction_commit_result) \
{ \
TALER_LOG_WARNING ("Transaction commit failed in %s\n", __FUNCTION__); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} \
} /* end of scope opened by BEGIN_TRANSACTION */
/**
* Code to include to retry a transaction, must only be used in between
* #START_TRANSACTION and #COMMIT_TRANSACTION.
*
* @param session session handle
* @param connection connection handle
*/
#define RETRY_TRANSACTION(session,connection) \
do { \
TEH_plugin->rollback (TEH_plugin->cls, \
session); \
if (transaction_retries++ <= MAX_TRANSACTION_COMMIT_RETRIES) \
goto transaction_start_label; \
TALER_LOG_WARNING ("Transaction commit failed %u times in %s\n", \
transaction_retries, \
__FUNCTION__); \
return TEH_RESPONSE_reply_commit_error (connection, \
TALER_EC_DB_COMMIT_FAILED_ON_RETRY); \
} while (0)
/**
* Send a response for "/refresh/reveal".
*
* @param connection the connection to send the response to
* @param num_newcoins number of new coins for which we reveal data
* @param sigs array of @a num_newcoins signatures revealed
* @return a MHD result code
*/
static int
reply_refresh_reveal_success (struct MHD_Connection *connection,
unsigned int num_newcoins,
const struct TALER_DenominationSignature *sigs)
{
int newcoin_index;
json_t *root;
json_t *obj;
json_t *list;
int ret;
list = json_array ();
for (newcoin_index = 0; newcoin_index < num_newcoins; newcoin_index++)
{
obj = json_object ();
json_object_set_new (obj,
"ev_sig",
GNUNET_JSON_from_rsa_signature (sigs[newcoin_index].rsa_signature));
GNUNET_assert (0 ==
json_array_append_new (list,
obj));
}
root = json_object ();
json_object_set_new (root,
"ev_sigs",
list);
ret = TEH_RESPONSE_reply_json (connection,
root,
MHD_HTTP_OK);
json_decref (root);
return ret;
}
/**
* Send a response for a failed "/refresh/reveal", where the
* revealed value(s) do not match the original commitment.
*
* @param connection the connection to send the response to
* @param session info about session
* @param commit_coins array of @a num_newcoins committed envelopes at offset @a gamma
* @param denom_pubs array of @a num_newcoins denomination keys for the new coins
* @param gamma_tp transfer public key at offset @a gamma
* @return a MHD result code
*/
static int
reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_RefreshSession *session,
const struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TALER_TransferPublicKeyP *gamma_tp)
{
json_t *info_new;
json_t *info_commit_k;
unsigned int i;
info_new = json_array ();
info_commit_k = json_array ();
for (i=0;i<session->num_newcoins;i++)
{
const struct TALER_EXCHANGEDB_RefreshCommitCoin *cc;
json_t *cc_json;
GNUNET_assert (0 ==
json_array_append_new (info_new,
GNUNET_JSON_from_rsa_public_key (denom_pubs[i].rsa_public_key)));
cc = &commit_coins[i];
cc_json = json_pack ("{s:o}",
"coin_ev",
GNUNET_JSON_from_data (cc->coin_ev,
cc->coin_ev_size));
GNUNET_assert (0 ==
json_array_append_new (info_commit_k,
cc_json));
}
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_CONFLICT,
"{s:s, s:I, s:o, s:o, s:o, s:o, s:o, s:o, s:o, s:i}",
"error", "commitment violation",
"code", (json_int_t) TALER_EC_REFRESH_REVEAL_COMMITMENT_VIOLATION,
"coin_sig", GNUNET_JSON_from_data_auto (&session->melt.coin_sig),
"coin_pub", GNUNET_JSON_from_data_auto (&session->melt.coin.coin_pub),
"melt_amount_with_fee", TALER_JSON_from_amount (&session->melt.amount_with_fee),
"melt_fee", TALER_JSON_from_amount (&session->melt.melt_fee),
"newcoin_infos", info_new,
"commit_infos", info_commit_k,
"gamma_tp", GNUNET_JSON_from_data_auto (gamma_tp),
"gamma", (int) session->noreveal_index);
}
/**
* Check if the given @a transfer_privs correspond to an honest
* commitment for the given session.
* Checks that the transfer private keys match their commitments.
* Then derives the shared secret for each #TALER_CNC_KAPPA, and check that they match.
*
* @param connection the MHD connection to handle
* @param session database connection to use
* @param session_hash hash of session to query
* @param off commitment offset to check
* @param transfer_priv private transfer key
* @param melt information about the melted coin
* @param num_newcoins number of newcoins being generated
* @param denom_pubs array of @a num_newcoins keys for the new coins
* @param hash_context hash context to update by hashing in the data
* from this offset
* @return #GNUNET_OK if the committment was honest,
* #GNUNET_NO if there was a problem and we generated an error message
* #GNUNET_SYSERR if we could not even generate an error message
*/
static int
check_commitment (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
unsigned int off,
const struct TALER_TransferPrivateKeyP *transfer_priv,
const struct TALER_EXCHANGEDB_RefreshMelt *melt,
unsigned int num_newcoins,
const struct TALER_DenominationPublicKey *denom_pubs,
struct GNUNET_HashContext *hash_context)
{
struct TALER_TransferSecretP transfer_secret;
unsigned int j;
TALER_link_reveal_transfer_secret (transfer_priv,
&melt->coin.coin_pub,
&transfer_secret);
/* Check that the commitments for all new coins were correct */
for (j = 0; j < num_newcoins; j++)
{
struct TALER_FreshCoinP fc;
struct TALER_CoinSpendPublicKeyP coin_pub;
struct GNUNET_HashCode h_msg;
char *buf;
size_t buf_len;
TALER_setup_fresh_coin (&transfer_secret,
j,
&fc);
GNUNET_CRYPTO_eddsa_key_get_public (&fc.coin_priv.eddsa_priv,
&coin_pub.eddsa_pub);
GNUNET_CRYPTO_hash (&coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP),
&h_msg);
if (GNUNET_YES !=
GNUNET_CRYPTO_rsa_blind (&h_msg,
&fc.blinding_key.bks,
denom_pubs[j].rsa_public_key,
&buf,
&buf_len))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Blind failed (bad denomination key!?)\n");
return (MHD_YES ==
TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_REFRESH_REVEAL_BLINDING_ERROR,
"Blinding error"))
? GNUNET_NO : GNUNET_SYSERR;
}
GNUNET_CRYPTO_hash_context_read (hash_context,
buf,
buf_len);
GNUNET_free (buf);
}
return GNUNET_OK;
}
/**
* Exchange a coin as part of a refresh operation. Obtains the
* envelope from the database and performs the signing operation.
*
* @param connection the MHD connection to handle
* @param session database connection to use
* @param session_hash hash of session to query
* @param key_state key state to lookup denomination pubs
* @param denom_pub denomination key for the coin to create
* @param commit_coin the coin that was committed
* @param coin_off number of the coin
* @return NULL on error, otherwise signature over the coin
*/
static struct TALER_DenominationSignature
refresh_exchange_coin (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
struct TEH_KS_StateHandle *key_state,
const struct TALER_DenominationPublicKey *denom_pub,
const struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coin,
unsigned int coin_off)
{
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
struct TALER_DenominationSignature ev_sig;
dki = TEH_KS_denomination_key_lookup (key_state,
denom_pub,
TEH_KS_DKU_WITHDRAW);
if (NULL == dki)
{
GNUNET_break (0);
ev_sig.rsa_signature = NULL;
return ev_sig;
}
if (GNUNET_OK ==
TEH_plugin->get_refresh_out (TEH_plugin->cls,
session,
session_hash,
coin_off,
&ev_sig))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Returning cached reply for /refresh/reveal signature\n");
return ev_sig;
}
ev_sig.rsa_signature
= GNUNET_CRYPTO_rsa_sign_blinded (dki->denom_priv.rsa_private_key,
commit_coin->coin_ev,
commit_coin->coin_ev_size);
if (NULL == ev_sig.rsa_signature)
{
GNUNET_break (0);
return ev_sig;
}
if (GNUNET_SYSERR ==
TEH_plugin->insert_refresh_out (TEH_plugin->cls,
session,
session_hash,
coin_off,
&ev_sig))
{
GNUNET_break (0);
GNUNET_CRYPTO_rsa_signature_free (ev_sig.rsa_signature);
ev_sig.rsa_signature = NULL;
}
return ev_sig;
}
/**
* The client request was well-formed, now execute the DB transaction
* of a "/refresh/reveal" operation. We use the @a ev_sigs and
* @a commit_coins to clean up resources after this function returns
* as we might experience retries of the database transaction.
*
* @param connection the MHD connection to handle
* @param session database session
* @param session_hash hash identifying the refresh session
* @param refresh_session information about the refresh operation we are doing
* @param denom_pubs array of "num_newcoins" denomination keys for the new coins
* @param[out] ev_sigs where to store generated signatures for the new coins,
* array of length "num_newcoins", memory released by the
* caller
* @param[out] commit_coins array of length "num_newcoins" to be used for
* information about the new coins from the commitment.
* @return MHD result code
*/
static int
execute_refresh_reveal_transaction (struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
const struct GNUNET_HashCode *session_hash,
const struct TALER_EXCHANGEDB_RefreshSession *refresh_session,
const struct TALER_DenominationPublicKey *denom_pubs,
struct TALER_DenominationSignature *ev_sigs,
struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins)
{
unsigned int j;
struct TEH_KS_StateHandle *key_state;
int ret;
START_TRANSACTION (session, connection);
key_state = TEH_KS_acquire ();
for (j=0;j<refresh_session->num_newcoins;j++)
{
if (NULL == ev_sigs[j].rsa_signature) /* could be non-NULL during retries */
ev_sigs[j] = refresh_exchange_coin (connection,
session,
session_hash,
key_state,
&denom_pubs[j],
&commit_coins[j],
j);
if (NULL == ev_sigs[j].rsa_signature)
{
TEH_plugin->rollback (TEH_plugin->cls,
session);
ret = TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_SIGNING_ERROR);
goto cleanup;
}
}
COMMIT_TRANSACTION (session, connection);
ret = reply_refresh_reveal_success (connection,
refresh_session->num_newcoins,
ev_sigs);
cleanup:
TEH_KS_release (key_state);
return ret;
}
/**
* Execute a "/refresh/reveal". The client is revealing to us the
* transfer keys for @a #TALER_CNC_KAPPA-1 sets of coins. Verify that the
* revealed transfer keys would allow linkage to the blinded coins,
* and if so, return the signed coins for corresponding to the set of
* coins that was not chosen.
*
* @param connection the MHD connection to handle
* @param session_hash hash identifying the refresh session
* @param transfer_privs array with the revealed transfer keys,
* length must be #TALER_CNC_KAPPA - 1
* @return MHD result code
*/
static int
execute_refresh_reveal (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
struct TALER_TransferPrivateKeyP *transfer_privs)
{
int res;
struct TALER_EXCHANGEDB_Session *session;
struct TALER_EXCHANGEDB_RefreshSession refresh_session;
struct TALER_DenominationPublicKey *denom_pubs;
struct TALER_DenominationSignature *ev_sigs;
struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins;
unsigned int i;
unsigned int j;
unsigned int off;
struct GNUNET_HashContext *hash_context;
struct GNUNET_HashCode sh_check;
int ret;
struct TALER_TransferPublicKeyP gamma_tp;
if (NULL == (session = TEH_plugin->get_session (TEH_plugin->cls)))
{
GNUNET_break (0);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DB_SETUP_FAILED);
}
res = TEH_plugin->get_refresh_session (TEH_plugin->cls,
session,
session_hash,
&refresh_session);
if (GNUNET_NO == res)
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_REFRESH_REVEAL_SESSION_UNKNOWN,
"session_hash");
if ( (GNUNET_SYSERR == res) ||
(refresh_session.noreveal_index >= TALER_CNC_KAPPA) )
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_SESSION_ERROR);
denom_pubs = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_DenominationPublicKey);
if (GNUNET_OK !=
TEH_plugin->get_refresh_order (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
denom_pubs))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_ORDER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
hash_context = GNUNET_CRYPTO_hash_context_start ();
/* first, iterate over transfer public keys for hash_context */
off = 0;
for (i=0;i<TALER_CNC_KAPPA;i++)
{
if (i == refresh_session.noreveal_index)
{
off = 1;
/* obtain gamma_tp from db */
if (GNUNET_OK !=
TEH_plugin->get_refresh_transfer_public_key (TEH_plugin->cls,
session,
session_hash,
&gamma_tp))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_TRANSFER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
GNUNET_CRYPTO_hash_context_read (hash_context,
&gamma_tp,
sizeof (struct TALER_TransferPublicKeyP));
}
else
{
/* compute tp from private key */
struct TALER_TransferPublicKeyP tp;
GNUNET_CRYPTO_ecdhe_key_get_public (&transfer_privs[i - off].ecdhe_priv,
&tp.ecdhe_pub);
GNUNET_CRYPTO_hash_context_read (hash_context,
&tp,
sizeof (struct TALER_TransferPublicKeyP));
}
}
/* next, add all of the hashes from the denomination keys to the
hash_context */
{
struct TALER_DenominationPublicKey denom_pubs[refresh_session.num_newcoins];
if (GNUNET_OK !=
TEH_plugin->get_refresh_order (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
denom_pubs))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (MHD_YES == TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_ORDER_ERROR))
? GNUNET_NO : GNUNET_SYSERR;
}
for (i=0;i<refresh_session.num_newcoins;i++)
{
char *buf;
size_t buf_size;
buf_size = GNUNET_CRYPTO_rsa_public_key_encode (denom_pubs[i].rsa_public_key,
&buf);
GNUNET_CRYPTO_hash_context_read (hash_context,
buf,
buf_size);
GNUNET_free (buf);
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[i].rsa_public_key);
}
}
/* next, add public key of coin and amount being refreshed */
{
struct TALER_AmountNBO melt_amountn;
GNUNET_CRYPTO_hash_context_read (hash_context,
&refresh_session.melt.coin.coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP));
TALER_amount_hton (&melt_amountn,
&refresh_session.melt.amount_with_fee);
GNUNET_CRYPTO_hash_context_read (hash_context,
&melt_amountn,
sizeof (struct TALER_AmountNBO));
}
commit_coins = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_EXCHANGEDB_RefreshCommitCoin);
off = 0;
for (i=0;i<TALER_CNC_KAPPA;i++)
{
if (i == refresh_session.noreveal_index)
{
off = 1;
/* obtain commit_coins for the selected gamma value from DB */
if (GNUNET_OK !=
TEH_plugin->get_refresh_commit_coins (TEH_plugin->cls,
session,
session_hash,
refresh_session.num_newcoins,
commit_coins))
{
GNUNET_break (0);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_REVEAL_DB_FETCH_COMMIT_ERROR);
}
/* add envelopes to hash_context */
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_CRYPTO_hash_context_read (hash_context,
commit_coins[j].coin_ev,
commit_coins[j].coin_ev_size);
}
continue;
}
if (GNUNET_OK !=
(res = check_commitment (connection,
session,
session_hash,
i,
&transfer_privs[i - off],
&refresh_session.melt,
refresh_session.num_newcoins,
denom_pubs,
hash_context)))
{
GNUNET_break_op (0);
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
GNUNET_free (commit_coins[j].coin_ev);
}
GNUNET_free (commit_coins);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_CRYPTO_hash_context_abort (hash_context);
return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
}
}
/* Check session hash matches */
GNUNET_CRYPTO_hash_context_finish (hash_context,
&sh_check);
if (0 != memcmp (&sh_check,
session_hash,
sizeof (struct GNUNET_HashCode)))
{
GNUNET_break_op (0);
ret = reply_refresh_reveal_missmatch (connection,
&refresh_session,
commit_coins,
denom_pubs,
&gamma_tp);
for (j=0;j<refresh_session.num_newcoins;j++)
{
GNUNET_free (commit_coins[j].coin_ev);
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
}
GNUNET_free (commit_coins);
GNUNET_free (denom_pubs);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
return ret;
}
/* Client request OK, start transaction */
ev_sigs = GNUNET_new_array (refresh_session.num_newcoins,
struct TALER_DenominationSignature);
/* FIXME: might need to store revealed transfer private keys for
the auditor for later; should pass them as arguments here! #4792*/
res = execute_refresh_reveal_transaction (connection,
session,
session_hash,
&refresh_session,
denom_pubs,
ev_sigs,
commit_coins);
for (i=0;i<refresh_session.num_newcoins;i++)
{
if (NULL != ev_sigs[i].rsa_signature)
GNUNET_CRYPTO_rsa_signature_free (ev_sigs[i].rsa_signature);
GNUNET_free (commit_coins[i].coin_ev);
}
for (j=0;j<refresh_session.num_newcoins;j++)
if (NULL != denom_pubs[j].rsa_public_key)
GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
GNUNET_CRYPTO_rsa_signature_free (refresh_session.melt.coin.denom_sig.rsa_signature);
GNUNET_CRYPTO_rsa_public_key_free (refresh_session.melt.coin.denom_pub.rsa_public_key);
GNUNET_free (ev_sigs);
GNUNET_free (denom_pubs);
GNUNET_free (commit_coins);
return res;
}
/**
* Handle a "/refresh/reveal" request. Parses the given JSON
* transfer private keys and if successful, passes everything to
* #TEH_DB_execute_refresh_reveal() which will verify that the
* revealed information is valid then returns the signed refreshed
* coins.
*
* @param connection the MHD connection to handle
* @param session_hash hash identifying the melting session
* @param tp_json private transfer keys in JSON format
* @return MHD result code
*/
static int
handle_refresh_reveal_json (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
const json_t *tp_json)
{
struct TALER_TransferPrivateKeyP transfer_privs[TALER_CNC_KAPPA - 1];
unsigned int i;
int res;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"reveal request for session %s\n",
GNUNET_h2s (session_hash));
res = GNUNET_OK;
for (i = 0; i < TALER_CNC_KAPPA - 1; i++)
{
struct GNUNET_JSON_Specification tp_spec[] = {
GNUNET_JSON_spec_fixed_auto (NULL, &transfer_privs[i]),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK != res)
break;
res = TEH_PARSE_json_array (connection,
tp_json,
tp_spec,
i, -1);
GNUNET_break_op (GNUNET_OK == res);
}
if (GNUNET_OK != res)
res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
else
res = execute_refresh_reveal (connection,
session_hash,
transfer_privs);
return res;
}
/**
* Handle a "/refresh/reveal" request. This time, the client reveals
* the private transfer keys except for the cut-and-choose value
* returned from "/refresh/melt". This function parses the revealed
* keys and secrets and ultimately passes everything to
* #TEH_DB_execute_refresh_reveal() which will verify that the
* revealed information is valid then returns the signed refreshed
* coins.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_reveal (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
struct GNUNET_HashCode session_hash;
int res;
json_t *root;
json_t *transfer_privs;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("session_hash", &session_hash),
GNUNET_JSON_spec_json ("transfer_privs", &transfer_privs),
GNUNET_JSON_spec_end ()
};
res = TEH_PARSE_post_json (connection,
connection_cls,
upload_data,
upload_data_size,
&root);
if (GNUNET_SYSERR == res)
return MHD_NO;
if ( (GNUNET_NO == res) || (NULL == root) )
return MHD_YES;
res = TEH_PARSE_json_data (connection,
root,
spec);
json_decref (root);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
/* Determine dimensionality of the request (kappa and #old coins) */
/* Note we do +1 as 1 row (cut-and-choose!) is missing! */
if (TALER_CNC_KAPPA != json_array_size (transfer_privs) + 1)
{
GNUNET_JSON_parse_free (spec);
GNUNET_break_op (0);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_REFRESH_REVEAL_CNC_TRANSFER_ARRAY_SIZE_INVALID,
"transfer_privs");
}
res = handle_refresh_reveal_json (connection,
&session_hash,
transfer_privs);
GNUNET_JSON_parse_free (spec);
return res;
}
/* end of taler-exchange-httpd_refresh_reveal.c */

View File

@ -1,6 +1,6 @@
/* /*
This file is part of TALER This file is part of TALER
Copyright (C) 2014, 2015 GNUnet e.V. Copyright (C) 2014-2017 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software terms of the GNU Affero General Public License as published by the Free Software
@ -14,41 +14,20 @@
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/ */
/** /**
* @file taler-exchange-httpd_refresh.h * @file taler-exchange-httpd_refresh_reveal.h
* @brief Handle /refresh/ requests * @brief Handle /refresh/reveal requests
* @author Florian Dold * @author Florian Dold
* @author Benedikt Mueller * @author Benedikt Mueller
* @author Christian Grothoff * @author Christian Grothoff
*/ */
#ifndef TALER_EXCHANGE_HTTPD_REFRESH_H #ifndef TALER_EXCHANGE_HTTPD_REFRESH_REVEAL_H
#define TALER_EXCHANGE_HTTPD_REFRESH_H #define TALER_EXCHANGE_HTTPD_REFRESH_REVEAL_H
#include <gnunet/gnunet_util_lib.h> #include <gnunet/gnunet_util_lib.h>
#include <microhttpd.h> #include <microhttpd.h>
#include "taler-exchange-httpd.h" #include "taler-exchange-httpd.h"
/**
* Handle a "/refresh/melt" request. Parses the request into the JSON
* components and then hands things of to #handle_refresh_melt_json()
* to validate the melted coins, the signature and execute the melt
* using TEH_DB_execute_refresh_melt().
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size);
/** /**
* Handle a "/refresh/reveal" request. This time, the client reveals * Handle a "/refresh/reveal" request. This time, the client reveals
* the private transfer keys except for the cut-and-choose value * the private transfer keys except for the cut-and-choose value
@ -72,23 +51,4 @@ TEH_REFRESH_handler_refresh_reveal (struct TEH_RequestHandler *rh,
const char *upload_data, const char *upload_data,
size_t *upload_data_size); size_t *upload_data_size);
/**
* Handle a "/refresh/link" request
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size);
#endif #endif

View File

@ -878,251 +878,6 @@ TEH_RESPONSE_compile_reserve_history (const struct TALER_EXCHANGEDB_ReserveHisto
} }
/**
* Send a response for a failed "/refresh/melt" request. The
* transaction history of the given coin demonstrates that the
* @a residual value of the coin is below the @a requested
* contribution of the coin for the melt. Thus, the exchange
* refuses the melt operation.
*
* @param connection the connection to send the response to
* @param coin_pub public key of the coin
* @param coin_value original value of the coin
* @param tl transaction history for the coin
* @param requested how much this coin was supposed to contribute, including fee
* @param residual remaining value of the coin (after subtracting @a tl)
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_melt_insufficient_funds (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_Amount coin_value,
struct TALER_EXCHANGEDB_TransactionList *tl,
struct TALER_Amount requested,
struct TALER_Amount residual)
{
json_t *history;
history = TEH_RESPONSE_compile_transaction_history (tl);
if (NULL == history)
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_REFRESH_MELT_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS);
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_FORBIDDEN,
"{s:s, s:I, s:o, s:o, s:o, s:o, s:o}",
"error",
"insufficient funds",
"code",
(json_int_t) TALER_EC_REFRESH_MELT_INSUFFICIENT_FUNDS,
"coin_pub",
GNUNET_JSON_from_data_auto (coin_pub),
"original_value",
TALER_JSON_from_amount (&coin_value),
"residual_value",
TALER_JSON_from_amount (&residual),
"requested_value",
TALER_JSON_from_amount (&requested),
"history",
history);
}
/**
* Send a response to a "/refresh/melt" request.
*
* @param connection the connection to send the response to
* @param session_hash hash of the refresh session
* @param noreveal_index which index will the client not have to reveal
* @return a MHD status code
*/
int
TEH_RESPONSE_reply_refresh_melt_success (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
uint16_t noreveal_index)
{
struct TALER_RefreshMeltConfirmationPS body;
struct TALER_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
json_t *sig_json;
body.purpose.size = htonl (sizeof (struct TALER_RefreshMeltConfirmationPS));
body.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_MELT);
body.session_hash = *session_hash;
body.noreveal_index = htons (noreveal_index);
body.reserved = htons (0);
TEH_KS_sign (&body.purpose,
&pub,
&sig);
sig_json = GNUNET_JSON_from_data_auto (&sig);
GNUNET_assert (NULL != sig_json);
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:i, s:o, s:o}",
"noreveal_index", (int) noreveal_index,
"exchange_sig", sig_json,
"exchange_pub", GNUNET_JSON_from_data_auto (&pub));
}
/**
* Send a response for "/refresh/reveal".
*
* @param connection the connection to send the response to
* @param num_newcoins number of new coins for which we reveal data
* @param sigs array of @a num_newcoins signatures revealed
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_reveal_success (struct MHD_Connection *connection,
unsigned int num_newcoins,
const struct TALER_DenominationSignature *sigs)
{
int newcoin_index;
json_t *root;
json_t *obj;
json_t *list;
int ret;
list = json_array ();
for (newcoin_index = 0; newcoin_index < num_newcoins; newcoin_index++)
{
obj = json_object ();
json_object_set_new (obj,
"ev_sig",
GNUNET_JSON_from_rsa_signature (sigs[newcoin_index].rsa_signature));
GNUNET_assert (0 ==
json_array_append_new (list,
obj));
}
root = json_object ();
json_object_set_new (root,
"ev_sigs",
list);
ret = TEH_RESPONSE_reply_json (connection,
root,
MHD_HTTP_OK);
json_decref (root);
return ret;
}
/**
* Send a response for a failed "/refresh/reveal", where the
* revealed value(s) do not match the original commitment.
*
* @param connection the connection to send the response to
* @param session info about session
* @param commit_coins array of @a num_newcoins committed envelopes at offset @a gamma
* @param denom_pubs array of @a num_newcoins denomination keys for the new coins
* @param gamma_tp transfer public key at offset @a gamma
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_RefreshSession *session,
const struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TALER_TransferPublicKeyP *gamma_tp)
{
json_t *info_new;
json_t *info_commit_k;
unsigned int i;
info_new = json_array ();
info_commit_k = json_array ();
for (i=0;i<session->num_newcoins;i++)
{
const struct TALER_EXCHANGEDB_RefreshCommitCoin *cc;
json_t *cc_json;
GNUNET_assert (0 ==
json_array_append_new (info_new,
GNUNET_JSON_from_rsa_public_key (denom_pubs[i].rsa_public_key)));
cc = &commit_coins[i];
cc_json = json_pack ("{s:o}",
"coin_ev",
GNUNET_JSON_from_data (cc->coin_ev,
cc->coin_ev_size));
GNUNET_assert (0 ==
json_array_append_new (info_commit_k,
cc_json));
}
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_CONFLICT,
"{s:s, s:I, s:o, s:o, s:o, s:o, s:o, s:o, s:o, s:i}",
"error", "commitment violation",
"code", (json_int_t) TALER_EC_REFRESH_REVEAL_COMMITMENT_VIOLATION,
"coin_sig", GNUNET_JSON_from_data_auto (&session->melt.coin_sig),
"coin_pub", GNUNET_JSON_from_data_auto (&session->melt.coin.coin_pub),
"melt_amount_with_fee", TALER_JSON_from_amount (&session->melt.amount_with_fee),
"melt_fee", TALER_JSON_from_amount (&session->melt.melt_fee),
"newcoin_infos", info_new,
"commit_infos", info_commit_k,
"gamma_tp", GNUNET_JSON_from_data_auto (gamma_tp),
"gamma", (int) session->noreveal_index);
}
/**
* Send a response for "/refresh/link".
*
* @param connection the connection to send the response to
* @param num_sessions number of sessions the coin was used in
* @param sessions array of @a num_session entries with
* information for each session
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_link_success (struct MHD_Connection *connection,
unsigned int num_sessions,
const struct TEH_RESPONSE_LinkSessionInfo *sessions)
{
json_t *root;
json_t *mlist;
int res;
unsigned int i;
mlist = json_array ();
for (i=0;i<num_sessions;i++)
{
const struct TALER_EXCHANGEDB_LinkDataList *pos;
json_t *list = json_array ();
for (pos = sessions[i].ldl; NULL != pos; pos = pos->next)
{
json_t *obj;
obj = json_object ();
json_object_set_new (obj,
"denom_pub",
GNUNET_JSON_from_rsa_public_key (pos->denom_pub.rsa_public_key));
json_object_set_new (obj,
"ev_sig",
GNUNET_JSON_from_rsa_signature (pos->ev_sig.rsa_signature));
GNUNET_assert (0 ==
json_array_append_new (list,
obj));
}
root = json_object ();
json_object_set_new (root,
"new_coins",
list);
json_object_set_new (root,
"transfer_pub",
GNUNET_JSON_from_data_auto (&sessions[i].transfer_pub));
GNUNET_assert (0 ==
json_array_append_new (mlist,
root));
}
res = TEH_RESPONSE_reply_json (connection,
mlist,
MHD_HTTP_OK);
json_decref (mlist);
return res;
}
/** /**
* A merchant asked for details about a deposit, but * A merchant asked for details about a deposit, but
* we do not know anything about the deposit. Generate the * we do not know anything about the deposit. Generate the

View File

@ -300,111 +300,6 @@ TEH_RESPONSE_reply_transfer_pending (struct MHD_Connection *connection,
struct GNUNET_TIME_Absolute planned_exec_time); struct GNUNET_TIME_Absolute planned_exec_time);
/**
* Send a confirmation response to a "/refresh/melt" request.
*
* @param connection the connection to send the response to
* @param session_hash hash of the refresh session
* @param noreveal_index which index will the client not have to reveal
* @return a MHD status code
*/
int
TEH_RESPONSE_reply_refresh_melt_success (struct MHD_Connection *connection,
const struct GNUNET_HashCode *session_hash,
uint16_t noreveal_index);
/**
* Send a response for a failed "/refresh/melt" request. The
* transaction history of the given coin demonstrates that the
* @a residual value of the coin is below the @a requested
* contribution of the coin for the melt. Thus, the exchange
* refuses the melt operation.
*
* @param connection the connection to send the response to
* @param coin_pub public key of the coin
* @param coin_value original value of the coin
* @param tl transaction history for the coin
* @param requested how much this coin was supposed to contribute
* @param residual remaining value of the coin (after subtracting @a tl)
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_melt_insufficient_funds (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_Amount coin_value,
struct TALER_EXCHANGEDB_TransactionList *tl,
struct TALER_Amount requested,
struct TALER_Amount residual);
/**
* Send a response for "/refresh/reveal".
*
* @param connection the connection to send the response to
* @param num_newcoins number of new coins for which we reveal data
* @param sigs array of @a num_newcoins signatures revealed
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_reveal_success (struct MHD_Connection *connection,
unsigned int num_newcoins,
const struct TALER_DenominationSignature *sigs);
/**
* Send a response for a failed "/refresh/reveal", where the
* revealed value(s) do not match the original commitment.
*
* @param connection the connection to send the response to
* @param session info about session
* @param commit_coins array of @a num_newcoins committed envelopes at offset @a gamma
* @param denom_pubs array of @a num_newcoins denomination keys for the new coins
* @param gamma_tp transfer public key at offset @a gamma
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_RefreshSession *session,
const struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins,
const struct TALER_DenominationPublicKey *denom_pubs,
const struct TALER_TransferPublicKeyP *gamma_tp);
/**
* @brief Information for each session a coin was melted into.
*/
struct TEH_RESPONSE_LinkSessionInfo
{
/**
* Transfer public key of the coin.
*/
struct TALER_TransferPublicKeyP transfer_pub;
/**
* Linked data of coins being created in the session.
*/
struct TALER_EXCHANGEDB_LinkDataList *ldl;
};
/**
* Send a response for "/refresh/link".
*
* @param connection the connection to send the response to
* @param num_sessions number of sessions the coin was used in
* @param sessions array of @a num_session entries with
* information for each session
* @return a MHD result code
*/
int
TEH_RESPONSE_reply_refresh_link_success (struct MHD_Connection *connection,
unsigned int num_sessions,
const struct TEH_RESPONSE_LinkSessionInfo *sessions);
/** /**
* Compile the transaction history of a coin into a JSON object. * Compile the transaction history of a coin into a JSON object.
* *