diff options
Diffstat (limited to 'src/exchange/taler-exchange-httpd_refresh.c')
| -rw-r--r-- | src/exchange/taler-exchange-httpd_refresh.c | 911 |
1 files changed, 911 insertions, 0 deletions
diff --git a/src/exchange/taler-exchange-httpd_refresh.c b/src/exchange/taler-exchange-httpd_refresh.c new file mode 100644 index 000000000..45bbf3d4d --- /dev/null +++ b/src/exchange/taler-exchange-httpd_refresh.c @@ -0,0 +1,911 @@ +/* + This file is part of TALER + Copyright (C) 2014, 2015 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, If not, see <http://www.gnu.org/licenses/> +*/ +/** + * @file taler-exchange-httpd_refresh.c + * @brief Handle /refresh/ 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.h" +#include "taler-exchange-httpd_responses.h" +#include "taler-exchange-httpd_keystate.h" + + +/** + * 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 + * and then hand things of to execute the melt operation. + * + * @param connection the MHD connection to handle + * @param num_new_denoms number of coins to be created, size of y-dimension of @a commit_link array + * @param denom_pubs array of @a num_new_denoms keys + * @param coin_count number of coins to be melted, size of y-dimension of @a commit_coin array + * @param coin_melt_details array with @a coin_count entries with melting details + * @param session_hash hash over the data that the client commits to + * @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 commit_link 2d array of coin link commitments (what the exchange is + * to return via "/refresh/link" to enable linkage in the + * future) + * @return MHD result code + */ +static int +handle_refresh_melt_binary (struct MHD_Connection *connection, + unsigned int num_new_denoms, + const struct TALER_DenominationPublicKey *denom_pubs, + unsigned int coin_count, + const struct TMH_DB_MeltDetails *coin_melt_details, + const struct GNUNET_HashCode *session_hash, + struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin, + struct TALER_RefreshCommitLinkP *const* commit_link) +{ + unsigned int i; + struct TMH_KS_StateHandle *key_state; + struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dk; + struct TALER_EXCHANGEDB_DenominationKeyInformationP *dki; + struct TALER_Amount cost; + struct TALER_Amount total_cost; + struct TALER_Amount melt; + struct TALER_Amount value; + struct TALER_Amount fee_withdraw; + struct TALER_Amount fee_melt; + struct TALER_Amount total_melt; + + GNUNET_assert (GNUNET_OK == + TALER_amount_get_zero (TMH_exchange_currency_string, + &total_cost)); + key_state = TMH_KS_acquire (); + for (i=0;i<num_new_denoms;i++) + { + dk = TMH_KS_denomination_key_lookup (key_state, + &denom_pubs[i], + TMH_KS_DKU_WITHDRAW); + if (NULL == dk) + { + GNUNET_break_op (0); + TMH_KS_release (key_state); + return TMH_RESPONSE_reply_arg_invalid (connection, + "new_denoms"); + } + dki = &dk->issue; + TALER_amount_ntoh (&value, + &dki->properties.value); + TALER_amount_ntoh (&fee_withdraw, + &dki->properties.fee_withdraw); + if ( (GNUNET_OK != + TALER_amount_add (&cost, + &value, + &fee_withdraw)) || + (GNUNET_OK != + TALER_amount_add (&total_cost, + &cost, + &total_cost)) ) + { + GNUNET_break_op (0); + TMH_KS_release (key_state); + return TMH_RESPONSE_reply_internal_error (connection, + "cost calculation failure"); + } + } + + GNUNET_assert (GNUNET_OK == + TALER_amount_get_zero (TMH_exchange_currency_string, + &total_melt)); + for (i=0;i<coin_count;i++) + { + /* calculate contribution of the i-th melt by subtracting + the fee; add the rest to the total_melt value */ + dk = TMH_KS_denomination_key_lookup (key_state, + &coin_melt_details[i].coin_info.denom_pub, + TMH_KS_DKU_DEPOSIT); + if (NULL == dk) + { + GNUNET_break (0); + return TMH_RESPONSE_reply_arg_invalid (connection, + "denom_pub"); + } + dki = &dk->issue; + TALER_amount_ntoh (&fee_melt, + &dki->properties.fee_refresh); + if (GNUNET_OK != + TALER_amount_subtract (&melt, + &coin_melt_details->melt_amount_with_fee, + &fee_melt)) + { + GNUNET_break_op (0); + TMH_KS_release (key_state); + return TMH_RESPONSE_reply_external_error (connection, + "Melt contribution below melting fee"); + } + if (GNUNET_OK != + TALER_amount_add (&total_melt, + &melt, + &total_melt)) + { + GNUNET_break_op (0); + TMH_KS_release (key_state); + return TMH_RESPONSE_reply_internal_error (connection, + "balance calculation failure"); + } + } + TMH_KS_release (key_state); + if (0 != + TALER_amount_cmp (&total_cost, + &total_melt)) + { + GNUNET_break_op (0); + /* We require total value of coins being melted and + total value of coins being generated to match! */ + return TMH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s}", + "error", "value mismatch"); + } + return TMH_DB_execute_refresh_melt (connection, + session_hash, + num_new_denoms, + denom_pubs, + coin_count, + coin_melt_details, + commit_coin, + commit_link); +} + + +/** + * Extract public coin information from a JSON object. + * + * @param connection the connection to send error responses to + * @param coin_info the JSON object to extract the coin info from + * @param[out] r_melt_detail set to details about the coin's melting permission (if valid) + * @return #GNUNET_YES if coin public info in JSON was valid + * #GNUNET_NO JSON was invalid, response was generated + * #GNUNET_SYSERR on internal error + */ +static int +get_coin_public_info (struct MHD_Connection *connection, + json_t *coin_info, + struct TMH_DB_MeltDetails *r_melt_detail) +{ + int ret; + struct TALER_CoinSpendSignatureP melt_sig; + struct TALER_DenominationSignature sig; + struct TALER_DenominationPublicKey pk; + struct TALER_Amount amount; + struct TMH_PARSE_FieldSpecification spec[] = { + TMH_PARSE_member_fixed ("coin_pub", &r_melt_detail->coin_info.coin_pub), + TMH_PARSE_member_denomination_signature ("denom_sig", &sig), + TMH_PARSE_member_denomination_public_key ("denom_pub", &pk), + TMH_PARSE_member_fixed ("confirm_sig", &melt_sig), + TMH_PARSE_member_amount ("value_with_fee", &amount), + TMH_PARSE_MEMBER_END + }; + + ret = TMH_PARSE_json_data (connection, + coin_info, + spec); + if (GNUNET_OK != ret) + { + GNUNET_break_op (0); + return ret; + } + /* check exchange signature on the coin */ + r_melt_detail->coin_info.denom_sig = sig; + r_melt_detail->coin_info.denom_pub = pk; + if (GNUNET_OK != + TALER_test_coin_valid (&r_melt_detail->coin_info)) + { + GNUNET_break_op (0); + TMH_PARSE_release_data (spec); + r_melt_detail->coin_info.denom_sig.rsa_signature = NULL; + r_melt_detail->coin_info.denom_pub.rsa_public_key = NULL; + return (MHD_YES == + TMH_RESPONSE_reply_signature_invalid (connection, + "denom_sig")) + ? GNUNET_NO : GNUNET_SYSERR; + } + r_melt_detail->melt_sig = melt_sig; + r_melt_detail->melt_amount_with_fee = amount; + return GNUNET_OK; +} + + +/** + * Verify that the signature shows that this coin is to be melted into + * the given @a session_hash melting session, and that this is a valid + * coin (we know the denomination key and the signature on it is + * valid). Essentially, this does all of the per-coin checks that can + * be done before the transaction starts. + * + * @param connection the connection to send error responses to + * @param session_hash hash over refresh session the coin is melted into + * @param[in,out] melt_detail details about the coin's melting permission, + * the `melt_fee` is updated + * @return #GNUNET_YES if coin public info in JSON was valid + * #GNUNET_NO JSON was invalid, response was generated + * #GNUNET_SYSERR on internal error + */ +static int +verify_coin_public_info (struct MHD_Connection *connection, + const struct GNUNET_HashCode *session_hash, + struct TMH_DB_MeltDetails *melt_detail) +{ + struct TALER_RefreshMeltCoinAffirmationPS body; + struct TMH_KS_StateHandle *key_state; + struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki; + struct TALER_Amount fee_refresh; + + key_state = TMH_KS_acquire (); + dki = TMH_KS_denomination_key_lookup (key_state, + &melt_detail->coin_info.denom_pub, + TMH_KS_DKU_DEPOSIT); + if (NULL == dki) + { + TMH_KS_release (key_state); + TALER_LOG_WARNING ("Unknown denomination key in /refresh/melt request\n"); + return TMH_RESPONSE_reply_arg_unknown (connection, + "denom_pub"); + } + TALER_amount_ntoh (&fee_refresh, + &dki->issue.properties.fee_refresh); + melt_detail->melt_fee = fee_refresh; + body.purpose.size = htonl (sizeof (struct TALER_RefreshMeltCoinAffirmationPS)); + body.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_MELT); + body.session_hash = *session_hash; + TALER_amount_hton (&body.amount_with_fee, + &melt_detail->melt_amount_with_fee); + TALER_amount_hton (&body.melt_fee, + &fee_refresh); + body.coin_pub = melt_detail->coin_info.coin_pub; + if (TALER_amount_cmp (&fee_refresh, + &melt_detail->melt_amount_with_fee) > 0) + { + GNUNET_break_op (0); + TMH_KS_release (key_state); + return (MHD_YES == + TMH_RESPONSE_reply_external_error (connection, + "melt amount smaller than melting fee")) + ? GNUNET_NO : GNUNET_SYSERR; + } + + TMH_KS_release (key_state); + if (GNUNET_OK != + GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_MELT, + &body.purpose, + &melt_detail->melt_sig.eddsa_signature, + &melt_detail->coin_info.coin_pub.eddsa_pub)) + { + GNUNET_break_op (0); + if (MHD_YES != + TMH_RESPONSE_reply_signature_invalid (connection, + "confirm_sig")) + return GNUNET_SYSERR; + return GNUNET_NO; + } + return GNUNET_OK; +} + + +/** + * Release memory from the @a commit_coin array. + * + * @param commit_coin array to release + * @param kappa size of 1st dimension + * @param num_new_coins size of 2nd dimension + */ +static void +free_commit_coins (struct TALER_EXCHANGEDB_RefreshCommitCoin **commit_coin, + unsigned int kappa, + unsigned int num_new_coins) +{ + unsigned int i; + unsigned int j; + + for (i=0;i<kappa;i++) + { + if (NULL == commit_coin[i]) + break; + for (j=0;j<num_new_coins;j++) + { + GNUNET_free_non_null (commit_coin[i][j].coin_ev); + GNUNET_free_non_null (commit_coin[i][j].refresh_link); + } + GNUNET_free (commit_coin[i]); + } +} + + +/** + * Release memory from the @a commit_link array. + * + * @param commit_link array to release + * @param kappa size of 1st dimension + * @param num_old_coins size of 2nd dimension + */ +static void +free_commit_links (struct TALER_RefreshCommitLinkP **commit_link, + unsigned int kappa, + unsigned int num_old_coins) +{ + unsigned int i; + + for (i=0;i<kappa;i++) + { + if (NULL == commit_link[i]) + break; + GNUNET_free (commit_link[i]); + } +} + + +/** + * Handle a "/refresh/melt" request after the first parsing has happened. + * We now need to validate the coins being melted and the session signature + * and then hand things of to execute the melt operation. This function + * parses the JSON arrays and then passes processing on to + * #handle_refresh_melt_binary(). + * + * @param connection the MHD connection to handle + * @param new_denoms array of denomination keys + * @param melt_coins array of coins to melt + * @param num_oldcoins number of coins that are being melted + * @param transfer_pubs #TALER_CNC_KAPPA-dimensional array of @a num_oldcoins transfer keys + * @param secret_encs #TALER_CNC_KAPPA-dimensional array of @a num_oldcoins secrets + * @param num_newcoins number of coins that the refresh will generate + * @param coin_evs #TALER_CNC_KAPPA-dimensional array of @a num_newcoins envelopes to sign + * @param link_encs #TALER_CNC_KAPPA-dimensional array of @a num_newcoins encrypted links + * @return MHD result code + */ +static int +handle_refresh_melt_json (struct MHD_Connection *connection, + const json_t *new_denoms, + const json_t *melt_coins, + unsigned int num_oldcoins, + const json_t *transfer_pubs, + const json_t *secret_encs, + unsigned int num_newcoins, + const json_t *coin_evs, + const json_t *link_encs) +{ + int res; + unsigned int i; + unsigned int j; + struct TALER_DenominationPublicKey *denom_pubs; + unsigned int num_new_denoms; + struct TMH_DB_MeltDetails *coin_melt_details; + unsigned int coin_count; + struct GNUNET_HashCode session_hash; + struct GNUNET_HashContext *hash_context; + struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coin[TALER_CNC_KAPPA]; + struct TALER_RefreshCommitLinkP *commit_link[TALER_CNC_KAPPA]; + + /* For the signature check, we hash most of the inputs together + (except for the signatures on the coins). */ + hash_context = GNUNET_CRYPTO_hash_context_start (); + num_new_denoms = json_array_size (new_denoms); + denom_pubs = GNUNET_malloc (num_new_denoms * + sizeof (struct TALER_DenominationPublicKey)); + for (i=0;i<num_new_denoms;i++) + { + char *buf; + size_t buf_size; + + res = TMH_PARSE_navigate_json (connection, + new_denoms, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_RET_RSA_PUBLIC_KEY, + &denom_pubs[i].rsa_public_key); + if (GNUNET_OK != res) + { + res = (GNUNET_NO == res) ? MHD_YES : MHD_NO; + goto cleanup_denoms; + } + 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); + } + + coin_count = json_array_size (melt_coins); + coin_melt_details = GNUNET_new_array (coin_count, + struct TMH_DB_MeltDetails); + for (i=0;i<coin_count;i++) + { + /* decode JSON data on coin to melt */ + struct TALER_AmountNBO melt_amount; + + res = get_coin_public_info (connection, + json_array_get (melt_coins, i), + &coin_melt_details[i]); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_NO == res) ? MHD_YES : MHD_NO; + goto cleanup_melt_details; + } + /* Check that the client does not try to melt the same coin twice + into the same session! */ + for (j=0;j<i;j++) + { + if (0 == memcmp (&coin_melt_details[i].coin_info.coin_pub, + &coin_melt_details[j].coin_info.coin_pub, + sizeof (struct TALER_CoinSpendPublicKeyP))) + { + GNUNET_break_op (0); + res = TMH_RESPONSE_reply_external_error (connection, + "melting same coin twice in same session is not allowed"); + goto cleanup_melt_details; + } + } + TALER_amount_hton (&melt_amount, + &coin_melt_details[i].melt_amount_with_fee); + GNUNET_CRYPTO_hash_context_read (hash_context, + &coin_melt_details[i].coin_info.coin_pub, + sizeof (struct TALER_CoinSpendPublicKeyP)); + GNUNET_CRYPTO_hash_context_read (hash_context, + &melt_amount, + sizeof (struct TALER_AmountNBO)); + } + + /* parse JSON arrays into 2d binary arrays and hash everything + together for the signature check */ + memset (commit_coin, 0, sizeof (commit_coin)); + memset (commit_link, 0, sizeof (commit_link)); + for (i = 0; i < TALER_CNC_KAPPA; i++) + { + commit_coin[i] = GNUNET_malloc (num_newcoins * + sizeof (struct TALER_EXCHANGEDB_RefreshCommitCoin)); + for (j = 0; j < num_newcoins; j++) + { + char *link_enc; + size_t link_enc_size; + struct TALER_EXCHANGEDB_RefreshCommitCoin *rcc = &commit_coin[i][j]; + + res = TMH_PARSE_navigate_json (connection, + coin_evs, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_INDEX, (int) j, + TMH_PARSE_JNC_RET_DATA_VAR, + &rcc->coin_ev, + &rcc->coin_ev_size); + + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + goto cleanup; + } + + GNUNET_CRYPTO_hash_context_read (hash_context, + rcc->coin_ev, + rcc->coin_ev_size); + res = TMH_PARSE_navigate_json (connection, + link_encs, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_INDEX, (int) j, + TMH_PARSE_JNC_RET_DATA_VAR, + &link_enc, + &link_enc_size); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + goto cleanup; + } + rcc->refresh_link + = TALER_refresh_link_encrypted_decode (link_enc, + link_enc_size); + GNUNET_CRYPTO_hash_context_read (hash_context, + link_enc, + link_enc_size); + GNUNET_free (link_enc); + } + } + + for (i = 0; i < TALER_CNC_KAPPA; i++) + { + commit_link[i] = GNUNET_malloc (num_oldcoins * + sizeof (struct TALER_RefreshCommitLinkP)); + for (j = 0; j < num_oldcoins; j++) + { + struct TALER_RefreshCommitLinkP *rcl = &commit_link[i][j]; + + res = TMH_PARSE_navigate_json (connection, + transfer_pubs, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_INDEX, (int) j, + TMH_PARSE_JNC_RET_DATA, + &rcl->transfer_pub, + sizeof (struct TALER_TransferPublicKeyP)); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + goto cleanup; + } + res = TMH_PARSE_navigate_json (connection, + secret_encs, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_INDEX, (int) j, + TMH_PARSE_JNC_RET_DATA, + &rcl->shared_secret_enc, + sizeof (struct TALER_EncryptedLinkSecretP)); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + goto cleanup; + } + GNUNET_CRYPTO_hash_context_read (hash_context, + rcl, + sizeof (struct TALER_RefreshCommitLinkP)); + } + } + GNUNET_CRYPTO_hash_context_finish (hash_context, + &session_hash); + hash_context = NULL; + for (i=0;i<coin_count;i++) + { + /* verify signatures on coins to melt */ + res = verify_coin_public_info (connection, + &session_hash, + &coin_melt_details[i]); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + res = (GNUNET_NO == res) ? MHD_YES : MHD_NO; + goto cleanup; + } + } + + /* execute commit */ + res = handle_refresh_melt_binary (connection, + num_new_denoms, + denom_pubs, + coin_count, + coin_melt_details, + &session_hash, + commit_coin, + commit_link); + cleanup: + free_commit_coins (commit_coin, + TALER_CNC_KAPPA, + num_newcoins); + free_commit_links (commit_link, + TALER_CNC_KAPPA, + num_oldcoins); + cleanup_melt_details: + for (j=0;j<coin_count;j++) + { + if (NULL != coin_melt_details[j].coin_info.denom_pub.rsa_public_key) + GNUNET_CRYPTO_rsa_public_key_free (coin_melt_details[j].coin_info.denom_pub.rsa_public_key); + if (NULL != coin_melt_details[j].coin_info.denom_sig.rsa_signature) + GNUNET_CRYPTO_rsa_signature_free (coin_melt_details[j].coin_info.denom_sig.rsa_signature); + } + GNUNET_free (coin_melt_details); + cleanup_denoms: + for (j=0;j<num_new_denoms;j++) + if (NULL != denom_pubs[j].rsa_public_key) + GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key); + GNUNET_free (denom_pubs); + if (NULL != hash_context) + GNUNET_CRYPTO_hash_context_abort (hash_context); + return res; +} + + +/** + * 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 TMH_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 +TMH_REFRESH_handler_refresh_melt (struct TMH_RequestHandler *rh, + struct MHD_Connection *connection, + void **connection_cls, + const char *upload_data, + size_t *upload_data_size) +{ + json_t *root; + json_t *new_denoms; + json_t *melt_coins; + json_t *coin_evs; + json_t *link_encs; + json_t *transfer_pubs; + json_t *secret_encs; + unsigned int num_oldcoins; + unsigned int num_newcoins; + json_t *coin_detail; + int res; + struct TMH_PARSE_FieldSpecification spec[] = { + TMH_PARSE_member_array ("new_denoms", &new_denoms), + TMH_PARSE_member_array ("melt_coins", &melt_coins), + TMH_PARSE_member_array ("coin_evs", &coin_evs), + TMH_PARSE_member_array ("link_encs", &link_encs), + TMH_PARSE_member_array ("transfer_pubs", &transfer_pubs), + TMH_PARSE_member_array ("secret_encs", &secret_encs), + TMH_PARSE_MEMBER_END + }; + + res = TMH_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 = TMH_PARSE_json_data (connection, + root, + spec); + json_decref (root); + if (GNUNET_OK != res) + return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + + /* Determine dimensionality of the request (kappa, #old and #new coins) */ + if (TALER_CNC_KAPPA != json_array_size (coin_evs)) + { + GNUNET_break_op (0); + TMH_PARSE_release_data (spec); + return TMH_RESPONSE_reply_arg_invalid (connection, + "coin_evs"); + } + if (TALER_CNC_KAPPA != json_array_size (transfer_pubs)) + { + GNUNET_break_op (0); + TMH_PARSE_release_data (spec); + return TMH_RESPONSE_reply_arg_invalid (connection, + "transfer_pubs"); + } + res = TMH_PARSE_navigate_json (connection, + coin_evs, + TMH_PARSE_JNC_INDEX, (int) 0, + TMH_PARSE_JNC_RET_TYPED_JSON, + JSON_ARRAY, &coin_detail); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + TMH_PARSE_release_data (spec); + return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + } + num_newcoins = json_array_size (coin_detail); + json_decref (coin_detail); + res = TMH_PARSE_navigate_json (connection, + transfer_pubs, + TMH_PARSE_JNC_INDEX, (int) 0, + TMH_PARSE_JNC_RET_TYPED_JSON, + JSON_ARRAY, &coin_detail); + if (GNUNET_OK != res) + { + GNUNET_break_op (0); + TMH_PARSE_release_data (spec); + return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + } + num_oldcoins = json_array_size (coin_detail); + json_decref (coin_detail); + res = handle_refresh_melt_json (connection, + new_denoms, + melt_coins, + num_oldcoins, + transfer_pubs, + secret_encs, + num_newcoins, + coin_evs, + link_encs); + TMH_PARSE_release_data (spec); + return res; +} + + +/** + * Handle a "/refresh/reveal" request. Parses the given JSON + * transfer private keys and if successful, passes everything to + * #TMH_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 num_oldcoins length of the 2nd dimension of @a transfer_privs array + * @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, + unsigned int num_oldcoins, + const json_t *tp_json) +{ + struct TALER_TransferPrivateKeyP *transfer_privs[TALER_CNC_KAPPA - 1]; + unsigned int i; + unsigned int j; + int res; + + for (i = 0; i < TALER_CNC_KAPPA - 1; i++) + transfer_privs[i] = GNUNET_malloc (num_oldcoins * + sizeof (struct TALER_TransferPrivateKeyP)); + res = GNUNET_OK; + for (i = 0; i < TALER_CNC_KAPPA - 1; i++) + { + if (GNUNET_OK != res) + break; + for (j = 0; j < num_oldcoins; j++) + { + if (GNUNET_OK != res) + break; + res = TMH_PARSE_navigate_json (connection, + tp_json, + TMH_PARSE_JNC_INDEX, (int) i, + TMH_PARSE_JNC_INDEX, (int) j, + TMH_PARSE_JNC_RET_DATA, + &transfer_privs[i][j], + sizeof (struct TALER_TransferPrivateKeyP)); + GNUNET_break_op (GNUNET_OK == res); + } + } + if (GNUNET_OK != res) + res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + else + res = TMH_DB_execute_refresh_reveal (connection, + session_hash, + num_oldcoins, + transfer_privs); + for (i = 0; i < TALER_CNC_KAPPA - 1; i++) + GNUNET_free (transfer_privs[i]); + 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 + * #TMH_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 +TMH_REFRESH_handler_refresh_reveal (struct TMH_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; + unsigned int num_oldcoins; + json_t *reveal_detail; + json_t *root; + json_t *transfer_privs; + struct TMH_PARSE_FieldSpecification spec[] = { + TMH_PARSE_member_fixed ("session_hash", &session_hash), + TMH_PARSE_member_array ("transfer_privs", &transfer_privs), + TMH_PARSE_MEMBER_END + }; + + res = TMH_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 = TMH_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) + { + TMH_PARSE_release_data (spec); + GNUNET_break_op (0); + return TMH_RESPONSE_reply_arg_invalid (connection, + "transfer_privs"); + } + res = TMH_PARSE_navigate_json (connection, + transfer_privs, + TMH_PARSE_JNC_INDEX, 0, + TMH_PARSE_JNC_RET_TYPED_JSON, + JSON_ARRAY, + &reveal_detail); + if (GNUNET_OK != res) + { + TMH_PARSE_release_data (spec); + GNUNET_break_op (0); + return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; + } + num_oldcoins = json_array_size (reveal_detail); + json_decref (reveal_detail); + res = handle_refresh_reveal_json (connection, + &session_hash, + num_oldcoins, + transfer_privs); + TMH_PARSE_release_data (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 +TMH_REFRESH_handler_refresh_link (struct TMH_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 = TMH_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 TMH_DB_execute_refresh_link (connection, + &coin_pub); +} + + +/* end of taler-exchange-httpd_refresh.c */ |