diff options
| m--------- | contrib/gana | 0 | ||||
| -rw-r--r-- | src/exchange/taler-exchange-httpd_age-withdraw_reveal.c | 402 |
2 files changed, 315 insertions, 87 deletions
diff --git a/contrib/gana b/contrib/gana -Subproject 214bc664476333a2c042ae57911558d1325e725 +Subproject 02132ededc12a0a1cfd81f0ca76c384304e1525 diff --git a/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c b/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c index 65bbb4326..daefca4c5 100644 --- a/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c +++ b/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c @@ -42,7 +42,7 @@ struct AgeRevealContext /** * Public key of the reserve for with the age-withdraw commitment was * originally made. This parameter is provided by the client again - * during the call to reveal in order to save a database-lookup . + * during the call to reveal in order to save a database-lookup. */ struct TALER_ReservePublicKeyP reserve_pub; @@ -52,20 +52,41 @@ struct AgeRevealContext uint32_t num_coins; /** - * TODO:oec num_coins denoms + * #num_coins hashes of the denominations from which the coins are withdrawn. + * Those must support age restriction. */ struct TALER_DenominationHashP *denoms_h; /** - * TODO:oec num_coins blinded coins + * #num_coins denomination keys, found in the system, according to denoms_h; + */ + struct TEH_DenominationKey *denom_keys; + + /** + * #num_coins hases of blinded coins. */ struct TALER_BlindedCoinHashP *coin_evs; /** - * TODO:oec num_coins*(kappa - 1) disclosed coins + * Total sum of all denominations' values + **/ + struct TALER_Amount total_amount; + + /** + * Total sum of all denominations' fees + */ + struct TALER_Amount total_fee; + + /** + * #num_coins*(kappa - 1) disclosed coins. */ struct GNUNET_CRYPTO_EddsaPrivateKey *disclosed_coins; + /** + * The data from the original age-withdraw. Will be retrieved from + * the DB via @a ach. + */ + struct TALER_EXCHANGEDB_AgeWithdrawCommitment commitment; }; /** @@ -75,30 +96,35 @@ void age_reveal_context_free (struct AgeRevealContext *actx) { GNUNET_free (actx->denoms_h); + GNUNET_free (actx->denom_keys); GNUNET_free (actx->coin_evs); GNUNET_free (actx->disclosed_coins); } /** - * Handle a "/age-withdraw/$ACH/reveal request. Parses the given JSON - * ... TODO:oec:description + * Parse the json body of an '/age-withdraw/$ACH/reveal' request. It extracts + * the denomination hashes, blinded coins and disclosed coins and allocates + * memory for those. * * @param connection The MHD connection to handle - * @param actx The context of the operation, only partially built at call time * @param j_denoms_h Array of hashes of the denominations for the withdrawal, in JSON format * @param j_coin_evs The blinded envelopes in JSON format for the coins that are not revealed and will be signed on success * @param j_disclosed_coins The n*(kappa-1) disclosed coins' private keys in JSON format, from which all other attributes (age restriction, blinding, nonce) will be derived from + * @param[out] actx The context of the operation, only partially built at call time + * @param[out] mhd_mret The result if a reply is queued for MHD + * @return true on success, false on failure, with a reply already queued for MHD. */ -MHD_RESULT -handle_age_withdraw_reveal_json ( +static enum GNUNET_GenericReturnValue +parse_age_withdraw_reveal_json ( struct MHD_Connection *connection, - struct AgeRevealContext *actx, const json_t *j_denoms_h, const json_t *j_coin_evs, - const json_t *j_disclosed_coins) + const json_t *j_disclosed_coins, + struct AgeRevealContext *actx, + MHD_RESULT *mhd_ret) { - MHD_RESULT mhd_ret = MHD_NO; + enum GNUNET_GenericReturnValue result = GNUNET_SYSERR; /* Verify JSON-structure consistency */ { @@ -116,135 +142,309 @@ handle_age_withdraw_reveal_json ( error = "denoms_h must not be empty"; else if (actx->num_coins != json_array_size (j_coin_evs)) error = "denoms_h and coins_evs must be arrays of the same size"; - else if (actx->num_coins * (TALER_CNC_KAPPA - 1) - != json_array_size (j_disclosed_coins)) - error = "the size of array disclosed_coins must be " - TALER_CNC_KAPPA_MINUS_ONE_STR " times of the size of denoms_h"; else if (actx->num_coins > TALER_MAX_FRESH_COINS) /** - * FIXME?: If the user had commited to more than the maximum coins allowed, - * the reserve has been charged, but now the user can not withdraw any money - * from it. How can the user get their money back? + * The wallet had committed to more than the maximum coins allowed, the + * reserve has been charged, but now the user can not withdraw any money + * from it. Note that the user can't get their money back in this case! **/ error = "maximum number of coins that can be withdrawn has been exceeded"; + else if (actx->num_coins * (TALER_CNC_KAPPA - 1) + != json_array_size (j_disclosed_coins)) + error = "the size of array disclosed_coins must be " + TALER_CNC_KAPPA_MINUS_ONE_STR " times the size of denoms_h"; if (NULL != error) - return TALER_MHD_reply_with_error (connection, - MHD_HTTP_BAD_REQUEST, - TALER_EC_GENERIC_PARAMETER_MALFORMED, - error); + { + *mhd_ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + error); + return GNUNET_SYSERR; + } } - /* Parse denomination keys */ + /* Continue parsing the parts */ { - unsigned int idx; - json_t *jh; + unsigned int idx = 0; + json_t *value = NULL; + /* Parse denomination keys */ actx->denoms_h = GNUNET_new_array (actx->num_coins, struct TALER_DenominationHashP); - json_array_foreach (j_denoms_h, idx, jh) { + json_array_foreach (j_denoms_h, idx, value) { struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto (NULL, &actx->denoms_h[idx]), GNUNET_JSON_spec_end () }; if (GNUNET_OK != - GNUNET_JSON_parse (jh, spec, NULL, NULL)) + GNUNET_JSON_parse (value, spec, NULL, NULL)) { char msg[256] = {0}; GNUNET_snprintf (msg, sizeof(msg), "couldn't parse entry no. %d in array denoms_h", idx + 1); - mhd_ret = TALER_MHD_reply_with_error (connection, - MHD_HTTP_BAD_REQUEST, - TALER_EC_GENERIC_PARAMETER_MALFORMED, - msg); + *mhd_ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + msg); goto EXIT; } - }; - } - - /* Parse blinded envelopes */ - { - unsigned int idx; - json_t *ce; + /* Parse blinded envelopes */ actx->coin_evs = GNUNET_new_array (actx->num_coins, struct TALER_BlindedCoinHashP); - json_array_foreach (j_coin_evs, idx, ce) { + json_array_foreach (j_coin_evs, idx, value) { struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto (NULL, &actx->coin_evs[idx]), GNUNET_JSON_spec_end () }; if (GNUNET_OK != - GNUNET_JSON_parse (ce, spec, NULL, NULL)) + GNUNET_JSON_parse (value, spec, NULL, NULL)) { char msg[256] = {0}; GNUNET_snprintf (msg, sizeof(msg), "couldn't parse entry no. %d in array coin_evs", idx + 1); - mhd_ret = TALER_MHD_reply_with_error (connection, - MHD_HTTP_BAD_REQUEST, - TALER_EC_GENERIC_PARAMETER_MALFORMED, - msg); + *mhd_ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + msg); goto EXIT; } }; - } - - /* Parse diclosed keys */ - { - unsigned int idx; - json_t *dc; + /* Parse diclosed keys */ actx->disclosed_coins = GNUNET_new_array ( - actx->num_coins * (TALER_CNC_KAPPA), + actx->num_coins * (TALER_CNC_KAPPA - 1), struct GNUNET_CRYPTO_EddsaPrivateKey); - json_array_foreach (j_coin_evs, idx, dc) { + json_array_foreach (j_disclosed_coins, idx, value) { struct GNUNET_JSON_Specification spec[] = { GNUNET_JSON_spec_fixed_auto (NULL, &actx->disclosed_coins[idx]), GNUNET_JSON_spec_end () }; if (GNUNET_OK != - GNUNET_JSON_parse (dc, spec, NULL, NULL)) + GNUNET_JSON_parse (value, spec, NULL, NULL)) { char msg[256] = {0}; GNUNET_snprintf (msg, sizeof(msg), "couldn't parse entry no. %d in array disclosed_coins", idx + 1); - mhd_ret = TALER_MHD_reply_with_error (connection, - MHD_HTTP_BAD_REQUEST, - TALER_EC_GENERIC_PARAMETER_MALFORMED, - msg); + *mhd_ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + msg); goto EXIT; } }; - } - /* TODO:oec: find commitment */ - /* TODO:oec: check validity of denoms */ - /* TODO:oec: check amount total against denoms */ - /* TODO:oec: compute the disclosed blinded coins */ - /* TODO:oec: generate h_commitment_comp */ - /* TODO:oec: compare h_commitment_comp against h_commitment */ - /* TODO:oec: sign the coins */ - /* TODO:oec: send response */ + result = GNUNET_OK; + *mhd_ret = MHD_YES; - /* TODO */ EXIT: - age_reveal_context_free (actx); - return mhd_ret; + return result; +} + + +/** + * Check if the request belongs to an existing age-withdraw request. + * If so, sets the age_withdraw object with the request data. + * Otherwise, it queues an appropriate MHD response. + * + * @param connection The HTTP connection to the client + * @param h_commitment Original commitment value sent with the age-withdraw request + * @param reserve_pub Reserve public key used in the original age-withdraw request + * @param[out] commitment Data from the original age-withdraw request + * @param[out] result In the error cases, a response will be queued with MHD and this will be the result. + * @return GNUNET_OK if the withdraw request has been found, + * GNUNET_SYSERROR if we did not find the request in the DB + */ +static enum GNUNET_GenericReturnValue +retrieve_original_commitment ( + struct MHD_Connection *connection, + const struct TALER_AgeWithdrawCommitmentHashP *h_commitment, + const struct TALER_ReservePublicKeyP *reserve_pub, + struct TALER_EXCHANGEDB_AgeWithdrawCommitment *commitment, + MHD_RESULT *result) +{ + enum GNUNET_DB_QueryStatus qs; + + qs = TEH_plugin->get_age_withdraw_info (TEH_plugin->cls, + reserve_pub, + h_commitment, + commitment); + switch (qs) + { + case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT: + return GNUNET_OK; /* Only happy case */ + + case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS: + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_NOT_FOUND, + TALER_EC_EXCHANGE_AGE_WITHDRAW_COMMITMENT_UNKNOWN, + NULL); + break; + + case GNUNET_DB_STATUS_HARD_ERROR: + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_DB_FETCH_FAILED, + "get_age_withdraw_info"); + break; + + case GNUNET_DB_STATUS_SOFT_ERROR: + /* FIXME: Do we queue a result in this case or retry? */ + default: + GNUNET_break (0); /* should be impossible */ + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE, + NULL); + } + + return GNUNET_SYSERR; +} + + +/** + * Check if the given array of hashes of denomination_keys a) belong + * to valid denominations and b) those are marked as age restricted. + * + * @param connection The HTTP connection to the client + * @param len The lengths of the array @a denoms_h + * @param denoms_h array of hashes of denomination public keys + * @param[out] dks On success, will be filled with the denomination keys. Caller must deallocate. + * @param amount_with_fee The commited amount including fees + * @param[out] total_sum On success, will contain the total sum of all denominations + * @param[out] total_fee On success, will contain the total sum of all fees + * @param[out] result In the error cases, a response will be queued with MHD and this will be the result. + * @return GNUNET_OK if the denominations are valid and support age-restriction + * GNUNET_SYSERR otherwise + */ +static enum GNUNET_GenericReturnValue +all_denominations_valid ( + struct MHD_Connection *connection, + uint32_t len, + const struct TALER_DenominationHashP *denoms_h, + struct TEH_DenominationKey **dks, + const struct TALER_Amount *amount_with_fee, + struct TALER_Amount *total_amount, + struct TALER_Amount *total_fee, + MHD_RESULT *result) +{ + struct TEH_KeyStateHandle *ksh; + + GNUNET_assert (*dks == NULL); + + ksh = TEH_keys_get_state (); + if (NULL == ksh) + { + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING, + NULL); + return GNUNET_SYSERR; + } + + *dks = GNUNET_new_array (len, struct TEH_DenominationKey); + TALER_amount_set_zero (TEH_currency, total_amount); + TALER_amount_set_zero (TEH_currency, total_fee); + + for (uint32_t i = 0; i < len; i++) + { + dks[i] = TEH_keys_denomination_by_hash2 ( + ksh, + &denoms_h[i], + connection, + result); + + /* Does the denomination exist? */ + if (NULL == dks[i]) + { + GNUNET_assert (result != NULL); + /* Note: a HTTP-response has been queued and result has been set by + * TEH_keys_denominations_by_hash2 */ + return GNUNET_SYSERR; + } + + /* Does the denomation support age restriction ? */ + if (0 == dks[i]->denom_pub.age_mask.bits) + { + char msg[256] = {0}; + GNUNET_snprintf (msg, + sizeof(msg), + "denomination key no. %d does not support age restriction", + i + 1); + + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN, + msg); + return GNUNET_SYSERR; + } + + /* Accumulate the values */ + if (0 > TALER_amount_add ( + total_amount, + total_amount, + &dks[i]->meta.value)) + { + GNUNET_break (0); + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_EXCHANGE_AGE_WITHDRAW_AMOUNT_OVERFLOW, + "amount"); + return GNUNET_SYSERR; + } + + /* Accumulate the withdraw fees */ + if (0 > TALER_amount_add ( + total_fee, + total_fee, + &dks[i]->meta.fees.withdraw)) + { + GNUNET_break (0); + *result = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_EXCHANGE_AGE_WITHDRAW_AMOUNT_OVERFLOW, + "fee"); + return GNUNET_SYSERR; + } + } + + /* Compare the commited amount against the totals */ + { + struct TALER_Amount sum; + TALER_amount_set_zero (TEH_currency, &sum); + + GNUNET_assert (0 < TALER_amount_add ( + &sum, + total_amount, + total_fee)); + + if (0 != TALER_amount_cmp (&sum, amount_with_fee)) + { + GNUNET_break (0); + *result = TALER_MHD_reply_with_ec (connection, + TALER_EC_EXCHANGE_AGE_WITHDRAW_AMOUNT_INCORRECT, + NULL); + return GNUNET_SYSERR; + } + } + + return GNUNET_OK; } @@ -254,6 +454,8 @@ TEH_handler_age_withdraw_reveal ( const struct TALER_AgeWithdrawCommitmentHashP *ach, const json_t *root) { + MHD_RESULT result = MHD_NO; + enum GNUNET_GenericReturnValue ret = GNUNET_SYSERR; struct AgeRevealContext actx = {0}; json_t *j_denoms_h; json_t *j_coin_evs; @@ -270,33 +472,59 @@ TEH_handler_age_withdraw_reveal ( /* Parse JSON body*/ { - enum GNUNET_GenericReturnValue res; - - res = TALER_MHD_parse_json_data (rc->connection, + ret = TALER_MHD_parse_json_data (rc->connection, root, spec); - if (GNUNET_OK != res) + if (GNUNET_OK != ret) { GNUNET_break_op (0); - return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + return (GNUNET_SYSERR == ret) ? MHD_NO : MHD_YES; } } - /* handle reveal request */ - { - MHD_RESULT res; - - res = handle_age_withdraw_reveal_json (rc->connection, - &actx, - j_denoms_h, - j_coin_evs, - j_disclosed_coins); + do { + /* Extract denominations, blinded and disclosed coins */ + if (GNUNET_OK != parse_age_withdraw_reveal_json (rc->connection, + j_denoms_h, + j_coin_evs, + j_disclosed_coins, + &actx, + &result)) + break; + + /* Find original commitment */ + if (GNUNET_OK != retrieve_original_commitment (rc->connection, + &actx.ach, + &actx.reserve_pub, + &actx.commitment, + &result)) + break; + + /* Ensure validity of denoms and the sum of amounts and fees */ + if (GNUNET_OK != all_denominations_valid ( + rc->connection, + actx.num_coins, + actx.denoms_h, + &actx.denom_keys, + &actx.commitment.amount_with_fee, + &actx.total_amount, + &actx.total_fee, + &result)) + break; + + + } while(0); - GNUNET_JSON_parse_free (spec); - return res; - } + /* TODO:oec: compute the disclosed blinded coins */ + /* TODO:oec: generate h_commitment_comp */ + /* TODO:oec: compare h_commitment_comp against h_commitment */ + /* TODO:oec: sign the coins */ + /* TODO:oec: send response */ + age_reveal_context_free (&actx); + GNUNET_JSON_parse_free (spec); + return result; } |