/* This file is part of TALER (C) 2014, 2015 Christian Grothoff (and other contributing authors) TALER is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. TALER is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with TALER; see the file COPYING. If not, If not, see */ /** * @file taler-mint-httpd_db.c * @brief High-level (transactional-layer) database operations for the mint. * @author Christian Grothoff * * TODO: * - actually abstract DB implementation (i.e. via plugin logic) * (this file should remain largely unchanged with the exception * of the PQ-specific DB handle types) * - /refresh/melt: all * + properly check all conditions and handle errors * + properly check transaction logic * + check for leaks * + check low-level API * - /refresh/commit: all * + properly check all conditions and handle errors * + properly check transaction logic * + check for leaks * + check low-level API * - /refresh/reveal: all * + properly check all conditions and handle errors * + properly check transaction logic * + check for leaks * + check low-level API * - /refresh/link: all * + properly check all conditions and handle errors * + properly check transaction logic * + check for leaks * + check low-level API */ #include "platform.h" #include #include #include "taler-mint-httpd_db.h" #include "taler_signatures.h" #include "taler-mint-httpd_keys.h" #include "taler-mint-httpd_responses.h" #include "mint_db.h" #include "mint.h" #include "taler_util.h" #include "taler-mint-httpd_keystate.h" /** * Get an amount in the mint's currency that is zero. * * @return zero amount in the mint's currency */ static struct TALER_Amount mint_amount_native_zero () { struct TALER_Amount amount; memset (&amount, 0, sizeof (amount)); memcpy (amount.currency, MINT_CURRENCY, strlen (MINT_CURRENCY) + 1); return amount; } /** * Execute a deposit. The validity of the coin and signature * have already been checked. The database must now check that * the coin is not (double or over) spent, and execute the * transaction (record details, generate success or failure response). * * @param connection the MHD connection to handle * @param deposit information about the deposit * @return MHD result code */ int TALER_MINT_db_execute_deposit (struct MHD_Connection *connection, const struct Deposit *deposit) { PGconn *db_conn; struct TALER_MINT_DB_TransactionList *tl; struct TALER_MINT_DB_TransactionList *pos; struct TALER_Amount spent; struct TALER_Amount value; struct TALER_Amount fee_deposit; struct TALER_Amount fee_withdraw; struct TALER_Amount fee_refresh; struct MintKeyState *mks; struct TALER_MINT_DenomKeyIssuePriv *dki; int ret; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_YES == TALER_MINT_DB_have_deposit (db_conn, deposit)) { return TALER_MINT_reply_deposit_success (connection, &deposit->coin.coin_pub, &deposit->h_wire, &deposit->h_contract, deposit->transaction_id, &deposit->merchant_pub, &deposit->amount); } mks = TALER_MINT_key_state_acquire (); dki = TALER_MINT_get_denom_key (mks, deposit->coin.denom_pub); value = TALER_amount_ntoh (dki->issue.value); fee_deposit = TALER_amount_ntoh (dki->issue.fee_deposit); fee_refresh = TALER_amount_ntoh (dki->issue.fee_refresh); TALER_MINT_key_state_release (mks); if (GNUNET_OK != TALER_MINT_DB_transaction (db_conn)) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } tl = TALER_MINT_DB_get_coin_transactions (db_conn, &deposit->coin.coin_pub); spent = fee_withdraw; /* fee for THIS transaction */ /* FIXME: need to deal better with integer overflows in the logic that follows! (change amount.c API! -- #3637) */ spent = TALER_amount_add (spent, deposit->amount); for (pos = tl; NULL != pos; pos = pos->next) { switch (pos->type) { case TALER_MINT_DB_TT_DEPOSIT: spent = TALER_amount_add (spent, pos->details.deposit->amount); spent = TALER_amount_add (spent, fee_deposit); break; case TALER_MINT_DB_TT_REFRESH_MELT: spent = TALER_amount_add (spent, pos->details.melt->amount); spent = TALER_amount_add (spent, fee_refresh); break; case TALER_MINT_DB_TT_LOCK: /* should check if lock is still active, and if it is for THIS operation; if lock is inactive, delete it; if lock is for THIS operation, ignore it; if lock is for another operation, count it! */ GNUNET_assert (0); // FIXME: not implemented! (#3625) break; } } if (0 < TALER_amount_cmp (spent, value)) { TALER_MINT_DB_rollback (db_conn); ret = TALER_MINT_reply_insufficient_funds (connection, tl); TALER_MINT_DB_free_coin_transaction_list (tl); return ret; } TALER_MINT_DB_free_coin_transaction_list (tl); if (GNUNET_OK != TALER_MINT_DB_insert_deposit (db_conn, deposit)) { LOG_WARNING ("Failed to store /deposit information in database\n"); TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_OK != TALER_MINT_DB_commit (db_conn)) { LOG_WARNING ("/deposit transaction commit failed\n"); return TALER_MINT_reply_commit_error (connection); } return TALER_MINT_reply_deposit_success (connection, &deposit->coin.coin_pub, &deposit->h_wire, &deposit->h_contract, deposit->transaction_id, &deposit->merchant_pub, &deposit->amount); } /** * Execute a /withdraw/status. Given the public key of a reserve, * return the associated transaction history. * * @param connection the MHD connection to handle * @param reserve_pub public key of the reserve to check * @return MHD result code */ int TALER_MINT_db_execute_withdraw_status (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EddsaPublicKey *reserve_pub) { PGconn *db_conn; struct ReserveHistory *rh; int res; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } rh = TALER_MINT_DB_get_reserve_history (db_conn, reserve_pub); if (NULL == rh) return TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "Reserve not found"); res = TALER_MINT_reply_withdraw_status_success (connection, rh); TALER_MINT_DB_free_reserve_history (rh); return res; } /** * Execute a "/withdraw/sign". Given a reserve and a properly signed * request to withdraw a coin, check the balance of the reserve and * if it is sufficient, store the request and return the signed * blinded envelope. * * @param connection the MHD connection to handle * @param reserve public key of the reserve * @param denomination_pub public key of the denomination requested * @param blinded_msg blinded message to be signed * @param blinded_msg_len number of bytes in @a blinded_msg * @param signature signature over the withdraw request, to be stored in DB * @return MHD result code */ int TALER_MINT_db_execute_withdraw_sign (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EddsaPublicKey *reserve, const struct GNUNET_CRYPTO_rsa_PublicKey *denomination_pub, const char *blinded_msg, size_t blinded_msg_len, const struct GNUNET_CRYPTO_EddsaSignature *signature) { PGconn *db_conn; struct ReserveHistory *rh; const struct ReserveHistory *pos; struct MintKeyState *key_state; struct CollectableBlindcoin collectable; struct TALER_MINT_DenomKeyIssuePriv *dki; struct TALER_MINT_DenomKeyIssuePriv *tdki; struct GNUNET_CRYPTO_rsa_Signature *sig; struct TALER_Amount amount_required; struct TALER_Amount deposit_total; struct TALER_Amount withdraw_total; struct TALER_Amount balance; struct TALER_Amount value; struct GNUNET_HashCode h_blind; int res; GNUNET_CRYPTO_hash (blinded_msg, blinded_msg_len, &h_blind); if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } res = TALER_MINT_DB_get_collectable_blindcoin (db_conn, &h_blind, &collectable); if (GNUNET_SYSERR == res) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } /* Don't sign again if we have already signed the coin */ if (GNUNET_YES == res) { res = TALER_MINT_reply_withdraw_sign_success (connection, &collectable); GNUNET_CRYPTO_rsa_signature_free (collectable.sig); return res; } GNUNET_assert (GNUNET_NO == res); /* Check if balance is sufficient */ key_state = TALER_MINT_key_state_acquire (); dki = TALER_MINT_get_denom_key (key_state, denomination_pub); if (NULL == dki) { TALER_MINT_key_state_release (key_state); return TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "Denomination not found"); } if (GNUNET_OK != TALER_MINT_DB_transaction (db_conn)) { GNUNET_break (0); TALER_MINT_key_state_release (key_state); return TALER_MINT_reply_internal_db_error (connection); } rh = TALER_MINT_DB_get_reserve_history (db_conn, reserve); if (NULL == rh) { TALER_MINT_DB_rollback (db_conn); TALER_MINT_key_state_release (key_state); return TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "Reserve not found"); } /* calculate amount required including fees */ amount_required = TALER_amount_add (TALER_amount_ntoh (dki->issue.value), TALER_amount_ntoh (dki->issue.fee_withdraw)); /* calculate balance of the reserve */ res = 0; for (pos = rh; NULL != pos; pos = pos->next) { switch (pos->type) { case TALER_MINT_DB_RO_BANK_TO_MINT: if (0 == (res & 1)) deposit_total = pos->details.bank->amount; else deposit_total = TALER_amount_add (deposit_total, pos->details.bank->amount); res |= 1; break; case TALER_MINT_DB_RO_WITHDRAW_COIN: tdki = TALER_MINT_get_denom_key (key_state, pos->details.withdraw->denom_pub); value = TALER_amount_ntoh (tdki->issue.value); if (0 == (res & 2)) withdraw_total = value; else withdraw_total = TALER_amount_add (withdraw_total, value); res |= 2; break; } } /* FIXME: good place to assert deposit_total > withdraw_total... */ balance = TALER_amount_subtract (deposit_total, withdraw_total); if (0 < TALER_amount_cmp (amount_required, balance)) { TALER_MINT_key_state_release (key_state); TALER_MINT_DB_rollback (db_conn); res = TALER_MINT_reply_withdraw_sign_insufficient_funds (connection, rh); TALER_MINT_DB_free_reserve_history (rh); return res; } TALER_MINT_DB_free_reserve_history (rh); /* Balance is good, sign the coin! */ sig = GNUNET_CRYPTO_rsa_sign (dki->denom_priv, blinded_msg, blinded_msg_len); TALER_MINT_key_state_release (key_state); if (NULL == sig) { GNUNET_break (0); TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_error (connection, "Internal error"); } // FIXME: can we avoid the cast? collectable.denom_pub = (struct GNUNET_CRYPTO_rsa_PublicKey *) denomination_pub; collectable.sig = sig; collectable.reserve_pub = *reserve; collectable.reserve_sig = *signature; if (GNUNET_OK != TALER_MINT_DB_insert_collectable_blindcoin (db_conn, &h_blind, &collectable)) { GNUNET_break (0); GNUNET_CRYPTO_rsa_signature_free (sig); TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_OK != TALER_MINT_DB_commit (db_conn)) { LOG_WARNING ("/withdraw/sign transaction commit failed\n"); return TALER_MINT_reply_commit_error (connection); } res = TALER_MINT_reply_withdraw_sign_success (connection, &collectable); GNUNET_CRYPTO_rsa_signature_free (sig); return res; } /** * Insert all requested denominations into the DB, and compute the * required cost of the denominations, including fees. * * @param connection the connection to send an error response to * @param db_conn the database connection * @param key_state the mint's key state to use * @param session_pub the refresh session public key * @param denom_pubs_count number of entries in @a denom_pubs * @param denom_pubs array of public keys for the refresh * @return FIXME! */ static int refresh_accept_denoms (struct MHD_Connection *connection, PGconn *db_conn, const struct MintKeyState *key_state, const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub, unsigned int denom_pubs_count, struct GNUNET_CRYPTO_rsa_PublicKey *const*denom_pubs) { unsigned int i; int res; for (i = 0; i < denom_pubs_count; i++) { /* Insert the requested coin into the DB, so we'll know later * what denomination the request had */ if (GNUNET_OK != (res = TALER_MINT_DB_insert_refresh_order (db_conn, i, session_pub, denom_pubs[i]))) return res; // ??? } return GNUNET_OK; } /** * Parse coin melt requests from a JSON object and write them to * the database. * * @param connection the connection to send errors to * @param db_conn the database connection * @param key_state the mint's key state * @param session_pub the refresh session's public key * @param coin_count number of coins in @a coin_public_infos to melt * @param coin_public_infos the coins to melt * @param r_melt_balance FIXME * @return #GNUNET_OK on success, * #GNUNET_NO if an error message was generated, * #GNUNET_SYSERR on internal errors (no response generated) */ static int refresh_accept_melts (struct MHD_Connection *connection, PGconn *db_conn, const struct MintKeyState *key_state, const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub, unsigned int coin_count, const struct TALER_CoinPublicInfo *coin_public_infos, struct TALER_Amount *r_melt_balance) { size_t i; int res; memset (r_melt_balance, 0, sizeof (struct TALER_Amount)); for (i = 0; i < coin_count; i++) { struct TALER_MINT_DenomKeyIssue *dki; struct KnownCoin known_coin; // money the customer gets by melting the current coin struct TALER_Amount coin_gain; struct RefreshMelt melt; dki = &(TALER_MINT_get_denom_key (key_state, coin_public_infos[i].denom_pub)->issue); if (NULL == dki) return (MHD_YES == TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "denom not found")) ? GNUNET_NO : GNUNET_SYSERR; res = TALER_MINT_DB_get_known_coin (db_conn, &coin_public_infos[i].coin_pub, &known_coin); if (GNUNET_SYSERR == res) { GNUNET_break (0); return GNUNET_SYSERR; } if (GNUNET_YES == res) { if (GNUNET_YES == known_coin.is_refreshed) return (MHD_YES == TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "coin already refreshed")) ? GNUNET_NO : GNUNET_SYSERR; } else { known_coin.expended_balance = mint_amount_native_zero (); known_coin.public_info = coin_public_infos[i]; } known_coin.is_refreshed = GNUNET_YES; known_coin.refresh_session_pub = *session_pub; if (GNUNET_OK != TALER_MINT_DB_upsert_known_coin (db_conn, &known_coin)) { GNUNET_break (0); return GNUNET_SYSERR; } // FIXME: test first if coin was already melted // in this session, etc. melt.coin = coin_public_infos[i]; melt.session_pub = *session_pub; // melt.coin_sig = FIXME; // melt.amount = FIXME; melt.oldcoin_index = i; if (GNUNET_OK != TALER_MINT_DB_insert_refresh_melt (db_conn, &melt)) { GNUNET_break (0); return GNUNET_SYSERR; } coin_gain = TALER_amount_ntoh (dki->value); coin_gain = TALER_amount_subtract (coin_gain, known_coin.expended_balance); /* Refuse to refresh when the coin does not have enough money left to * pay the refreshing fees of the coin. */ if (TALER_amount_cmp (coin_gain, TALER_amount_ntoh (dki->fee_refresh)) < 0) return (MHD_YES == TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "depleted")) ? GNUNET_NO : GNUNET_SYSERR; coin_gain = TALER_amount_subtract (coin_gain, TALER_amount_ntoh (dki->fee_refresh)); *r_melt_balance = TALER_amount_add (*r_melt_balance, coin_gain); } 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 refresh_session_pub public key of the refresh session * @param client_signature signature of the client (matching @a refresh_session_pub) * over the melting request * @param num_new_denoms number of entries in @a denom_pubs * @param denum_pubs public keys of the coins we want to withdraw in the end * @param coin_count number of entries in @a coin_public_infos * @param coin_public_infos information about the coins to melt * @return MHD result code */ int TALER_MINT_db_execute_refresh_melt (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub, const struct GNUNET_CRYPTO_EddsaSignature *client_signature, unsigned int num_new_denoms, struct GNUNET_CRYPTO_rsa_PublicKey *const*denom_pubs, unsigned int coin_count, const struct TALER_CoinPublicInfo *coin_public_infos) { struct TALER_Amount melt_balance; struct MintKeyState *key_state; struct RefreshSession session; PGconn *db_conn; int res; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_OK != TALER_MINT_DB_transaction (db_conn)) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } res = TALER_MINT_DB_get_refresh_session (db_conn, refresh_session_pub, &session); if (GNUNET_YES == res) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_refresh_melt_success (connection, &session.melt_sig, refresh_session_pub); } if (GNUNET_SYSERR == res) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } session.melt_sig = *client_signature; session.num_oldcoins = coin_count; session.num_newcoins = num_new_denoms; session.kappa = 0; /* FIXME: should be chosen by mint per config! */ session.noreveal_index = UINT16_MAX; session.has_commit_sig = GNUNET_NO; if (GNUNET_OK != (res = TALER_MINT_DB_create_refresh_session (db_conn, refresh_session_pub, &session))) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } /* The next two operations must see the same key state, * thus we acquire it here. */ key_state = TALER_MINT_key_state_acquire (); if (GNUNET_OK != (res = refresh_accept_denoms (connection, db_conn, key_state, refresh_session_pub, num_new_denoms, denom_pubs))) { TALER_MINT_key_state_release (key_state); TALER_MINT_DB_rollback (db_conn); return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; } /* Write old coins to db and sum their value */ if (GNUNET_OK != (res = refresh_accept_melts (connection, db_conn, key_state, refresh_session_pub, coin_count, coin_public_infos, &melt_balance))) { TALER_MINT_key_state_release (key_state); TALER_MINT_DB_rollback (db_conn); return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; } TALER_MINT_key_state_release (key_state); /* Request is only ok if cost of requested coins * does not exceed value of melted coins. */ if (GNUNET_OK != TALER_MINT_DB_commit (db_conn)) { LOG_WARNING ("/refresh/melt transaction commit failed\n"); return TALER_MINT_reply_commit_error (connection); } if (GNUNET_OK != (res = TALER_MINT_DB_get_refresh_session (db_conn, refresh_session_pub, &session))) { // FIXME: send internal error GNUNET_break (0); return MHD_NO; } return TALER_MINT_reply_refresh_melt_success (connection, client_signature, refresh_session_pub); } /** * Execute a "/refresh/commit". The client is committing to @a kappa * sets of transfer keys, and linkage information for a refresh * operation. Confirm that the commit matches the melts of an * existing @a refresh_session_pub, store the refresh session commit * data and then return the client a challenge specifying which of the * @a kappa sets of private transfer keys should not be revealed. * * @param connection the MHD connection to handle * @param refresh_session public key of the session * @param commit_client_sig signature of the client over this commitment * @param kappa size of x-dimension of @commit_coin and @commit_link arrays * @param num_oldcoins size of y-dimension of @commit_link array * @param num_newcoins size of y-dimension of @commit_coin array * @param commit_coin 2d array of coin commitments (what the mint is to sign * once the "/refres/reveal" of cut and choose is done) * @param commit_link 2d array of coin link commitments (what the mint is * to return via "/refresh/link" to enable linkage in the * future) * @return MHD result code */ int TALER_MINT_db_execute_refresh_commit (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub, const struct GNUNET_CRYPTO_EddsaSignature *commit_client_sig, unsigned int kappa, unsigned int num_oldcoins, unsigned int num_newcoins, struct RefreshCommitCoin *const*commit_coin, struct RefreshCommitLink *const*commit_link) { PGconn *db_conn; struct RefreshSession refresh_session; unsigned int i; unsigned int j; int res; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_OK != TALER_MINT_DB_transaction (db_conn)) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } res = TALER_MINT_DB_get_refresh_session (db_conn, refresh_session_pub, &refresh_session); if (GNUNET_SYSERR == res) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_NO == res) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_arg_invalid (connection, "session_pub"); } if ( (refresh_session.kappa != kappa) || (refresh_session.num_newcoins != num_newcoins) || (refresh_session.num_oldcoins != num_oldcoins) ) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_arg_invalid (connection, "dimensions"); } if (GNUNET_YES == refresh_session.has_commit_sig) { TALER_MINT_DB_rollback (db_conn); res = TALER_MINT_reply_refresh_commit_success (connection, &refresh_session); return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES; } for (i = 0; i < kappa; i++) { for (j = 0; j < num_newcoins; j++) { if (GNUNET_OK != TALER_MINT_DB_insert_refresh_commit_coin (db_conn, refresh_session_pub, i, j, &commit_coin[i][j])) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } } } for (i = 0; i < kappa; i++) { for (j = 0; j < num_oldcoins; j++) { if (GNUNET_OK != TALER_MINT_DB_insert_refresh_commit_link (db_conn, refresh_session_pub, i, j, &commit_link[i][j])) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } } } refresh_session.noreveal_index = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, refresh_session.kappa); if (GNUNET_OK != (res = TALER_MINT_DB_update_refresh_session (db_conn, refresh_session_pub, refresh_session.noreveal_index, commit_client_sig))) { TALER_MINT_DB_rollback (db_conn); return TALER_MINT_reply_internal_db_error (connection); } if (GNUNET_OK != TALER_MINT_DB_commit (db_conn)) { LOG_WARNING ("/refresh/commit transaction commit failed\n"); return TALER_MINT_reply_commit_error (connection); } return TALER_MINT_reply_refresh_commit_success (connection, &refresh_session); } /** * Send response for "/refresh/reveal". * * @param connection the MHD connection * @param db_conn the connection to the mint's db * @param refresh_session_pub the refresh session's public key * @return a MHD result code */ static int helper_refresh_reveal_send_response (struct MHD_Connection *connection, PGconn *db_conn, const struct RefreshSession *refresh_session, const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub) { int res; unsigned int newcoin_index; struct GNUNET_CRYPTO_rsa_Signature **sigs; sigs = GNUNET_malloc (refresh_session->num_newcoins * sizeof (struct GNUNET_CRYPTO_rsa_Signature *)); for (newcoin_index = 0; newcoin_index < refresh_session->num_newcoins; newcoin_index++) { sigs[newcoin_index] = TALER_MINT_DB_get_refresh_collectable (db_conn, newcoin_index, refresh_session_pub); if (NULL == sigs[newcoin_index]) { // FIXME: return 'internal error' GNUNET_break (0); GNUNET_free (sigs); return MHD_NO; } } res = TALER_MINT_reply_refresh_reveal_success (connection, refresh_session->num_newcoins, sigs); GNUNET_free (sigs); return res; } /** * Execute a "/refresh/reveal". The client is revealing to us the * transfer keys for @a 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 refresh_session_pub public key of the refresh session * @param kappa size of x-dimension of @transfer_privs array plus one (!) * @param num_oldcoins size of y-dimension of @transfer_privs array * @param transfer_pubs array with the revealed transfer keys * @return MHD result code */ int TALER_MINT_db_execute_refresh_reveal (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub, unsigned int kappa, unsigned int num_oldcoins, struct GNUNET_CRYPTO_EcdsaPrivateKey *const*transfer_privs) { int res; PGconn *db_conn; struct RefreshSession refresh_session; struct MintKeyState *key_state; unsigned int i; unsigned int j; unsigned int off; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } res = TALER_MINT_DB_get_refresh_session (db_conn, refresh_session_pub, &refresh_session); if (GNUNET_NO == res) return TALER_MINT_reply_arg_invalid (connection, "session_pub"); if (GNUNET_SYSERR == res) return TALER_MINT_reply_internal_db_error (connection); /* Check that the transfer private keys match their commitments. * Then derive the shared secret for each kappa, and check that they match. */ off = 0; for (i = 0; i < refresh_session.kappa - 1; i++) { struct TALER_LinkSecret last_shared_secret; int secret_initialized = GNUNET_NO; if (i == refresh_session.noreveal_index) off = 1; for (j = 0; j < refresh_session.num_oldcoins; j++) { struct RefreshCommitLink commit_link; struct TALER_TransferSecret transfer_secret; struct TALER_LinkSecret shared_secret; struct RefreshMelt melt; res = TALER_MINT_DB_get_refresh_commit_link (db_conn, refresh_session_pub, i + off, j, &commit_link); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return 'internal error'? return MHD_NO; } res = TALER_MINT_DB_get_refresh_melt (db_conn, refresh_session_pub, j, &melt); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return 'internal error'? return MHD_NO; } /* We're converting key types here, which is not very nice * but necessary and harmless (keys will be thrown away later). */ /* FIXME: ECDHE/ECDSA-key type confusion! Can we reduce/avoid this? */ if (GNUNET_OK != GNUNET_CRYPTO_ecc_ecdh ((const struct GNUNET_CRYPTO_EcdhePrivateKey *) &transfer_privs[i+off][j], (const struct GNUNET_CRYPTO_EcdhePublicKey *) &melt.coin.coin_pub, &transfer_secret.key)) { GNUNET_break (0); // FIXME: return 'internal error'? return MHD_NO; } if (GNUNET_OK != TALER_transfer_decrypt (&commit_link.shared_secret_enc, &transfer_secret, &shared_secret)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "decryption failed\n"); // FIXME: return 'internal error'? return MHD_NO; } if (GNUNET_NO == secret_initialized) { secret_initialized = GNUNET_YES; last_shared_secret = shared_secret; } else if (0 != memcmp (&shared_secret, &last_shared_secret, sizeof (struct GNUNET_HashCode))) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "shared secrets do not match\n"); // FIXME: return error code! return MHD_NO; } { struct GNUNET_CRYPTO_EcdsaPublicKey transfer_pub_check; GNUNET_CRYPTO_ecdsa_key_get_public (&transfer_privs[i+off][j], &transfer_pub_check); if (0 != memcmp (&transfer_pub_check, &commit_link.transfer_pub, sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey))) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "transfer keys do not match\n"); // FIXME: return error code! return MHD_NO; } } } /* Check that the commitments for all new coins were correct */ for (j = 0; j < refresh_session.num_newcoins; j++) { struct RefreshCommitCoin commit_coin; struct TALER_RefreshLinkDecrypted *link_data; // struct BlindedSignaturePurpose *coin_ev_check; struct GNUNET_CRYPTO_EcdsaPublicKey coin_pub; struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub; struct GNUNET_HashCode h_msg; char *buf; size_t buf_len; res = TALER_MINT_DB_get_refresh_commit_coin (db_conn, refresh_session_pub, i+off, j, &commit_coin); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } link_data = TALER_refresh_decrypt (commit_coin.refresh_link, &last_shared_secret); if (NULL == link_data) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "decryption failed\n"); // FIXME: return error code! return MHD_NO; } GNUNET_CRYPTO_ecdsa_key_get_public (&link_data->coin_priv, &coin_pub); denom_pub = TALER_MINT_DB_get_refresh_order (db_conn, j, refresh_session_pub); if (NULL == denom_pub) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } /* FIXME: we had envisioned a more complex scheme to derive the message to sign for a blinded coin... */ GNUNET_CRYPTO_hash (&coin_pub, sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey), &h_msg); if (0 == (buf_len = GNUNET_CRYPTO_rsa_blind (&h_msg, link_data->blinding_key, denom_pub, &buf))) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "blind failed\n"); // FIXME: return error code! return MHD_NO; } if ( (buf_len != commit_coin.coin_ev_size) || (0 != memcmp (buf, commit_coin.coin_ev, buf_len)) ) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "blind envelope does not match for kappa=%d, old=%d\n", (int) (i+off), (int) j); // FIXME: return error code! GNUNET_free (buf); return MHD_NO; } GNUNET_free (buf); } } if (GNUNET_OK != TALER_MINT_DB_transaction (db_conn)) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } for (j = 0; j < refresh_session.num_newcoins; j++) { struct RefreshCommitCoin commit_coin; struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub; struct TALER_MINT_DenomKeyIssuePriv *dki; struct GNUNET_CRYPTO_rsa_Signature *ev_sig; res = TALER_MINT_DB_get_refresh_commit_coin (db_conn, refresh_session_pub, refresh_session.noreveal_index % refresh_session.kappa, j, &commit_coin); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } denom_pub = TALER_MINT_DB_get_refresh_order (db_conn, j, refresh_session_pub); if (NULL == denom_pub) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } key_state = TALER_MINT_key_state_acquire (); dki = TALER_MINT_get_denom_key (key_state, denom_pub); TALER_MINT_key_state_release (key_state); if (NULL == dki) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } ev_sig = GNUNET_CRYPTO_rsa_sign (dki->denom_priv, commit_coin.coin_ev, commit_coin.coin_ev_size); if (NULL == ev_sig) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } res = TALER_MINT_DB_insert_refresh_collectable (db_conn, j, refresh_session_pub, ev_sig); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } } /* mark that reveal was successful */ res = TALER_MINT_DB_set_reveal_ok (db_conn, refresh_session_pub); if (GNUNET_OK != res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } if (GNUNET_OK != TALER_MINT_DB_commit (db_conn)) { LOG_WARNING ("/refresh/reveal transaction commit failed\n"); return TALER_MINT_reply_commit_error (connection); } return helper_refresh_reveal_send_response (connection, db_conn, &refresh_session, refresh_session_pub); } /** * FIXME: move into response generation logic! * FIXME: need to separate this from DB logic! */ static int link_iter (void *cls, const struct TALER_RefreshLinkEncrypted *link_data_enc, const struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub, const struct GNUNET_CRYPTO_rsa_Signature *ev_sig) { json_t *list = cls; json_t *obj = json_object (); char *buf; size_t buf_len; json_array_append_new (list, obj); json_object_set_new (obj, "link_enc", TALER_JSON_from_data (link_data_enc->coin_priv_enc, sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey) + link_data_enc->blinding_key_enc_size)); buf_len = GNUNET_CRYPTO_rsa_public_key_encode (denom_pub, &buf); json_object_set_new (obj, "denom_pub", TALER_JSON_from_data (buf, buf_len)); GNUNET_free (buf); buf_len = GNUNET_CRYPTO_rsa_signature_encode (ev_sig, &buf); json_object_set_new (obj, "ev_sig", TALER_JSON_from_data (buf, buf_len)); GNUNET_free (buf); return GNUNET_OK; } /** * 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 TALER_MINT_db_execute_refresh_link (struct MHD_Connection *connection, const struct GNUNET_CRYPTO_EcdsaPublicKey *coin_pub) { int res; json_t *root; json_t *list; PGconn *db_conn; struct GNUNET_CRYPTO_EcdsaPublicKey transfer_pub; struct GNUNET_HashCode shared_secret_enc; if (NULL == (db_conn = TALER_MINT_DB_get_connection ())) { GNUNET_break (0); return TALER_MINT_reply_internal_db_error (connection); } res = TALER_db_get_transfer (db_conn, coin_pub, &transfer_pub, &shared_secret_enc); if (GNUNET_SYSERR == res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } if (GNUNET_NO == res) { return TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "link data not found (transfer)"); } GNUNET_assert (GNUNET_OK == res); /* FIXME: separate out response generation logic! */ list = json_array (); root = json_object (); json_object_set_new (root, "new_coins", list); res = TALER_db_get_link (db_conn, coin_pub, &link_iter, list); if (GNUNET_SYSERR == res) { GNUNET_break (0); // FIXME: return error code! return MHD_NO; } if (GNUNET_NO == res) { return TALER_MINT_reply_json_pack (connection, MHD_HTTP_NOT_FOUND, "{s:s}", "error", "link data not found (link)"); } GNUNET_assert (GNUNET_OK == res); json_object_set_new (root, "transfer_pub", TALER_JSON_from_data (&transfer_pub, sizeof (struct GNUNET_CRYPTO_EddsaPublicKey))); json_object_set_new (root, "secret_enc", TALER_JSON_from_data (&shared_secret_enc, sizeof (struct GNUNET_HashCode))); res = TALER_MINT_reply_json (connection, root, MHD_HTTP_OK); json_decref (root); return res; } /* end of taler-mint-httpd_db.c */