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+/*
+ This file is part of TALER
+ Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
+
+ TALER is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file mint/mint_db.h
+ * @brief Low-level (statement-level) database access for the mint
+ * @author Florian Dold
+ * @author Christian Grothoff
+ */
+#ifndef MINT_DB_H
+#define MINT_DB_H
+
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_util.h"
+
+
+/**
+ * Information we keep on bank transfer(s) that established a reserve.
+ */
+struct BankTransfer
+{
+
+ /**
+ * Public key of the reserve that was filled.
+ */
+ struct GNUNET_CRYPTO_EddsaPublicKey reserve_pub;
+
+ /**
+ * Amount that was transferred to the mint.
+ */
+ struct TALER_Amount amount;
+
+ /**
+ * Detailed wire information about the transaction.
+ */
+ const json_t *wire;
+
+};
+
+
+/**
+ * A summary of a Reserve
+ */
+struct Reserve
+{
+ /**
+ * The reserve's public key. This uniquely identifies the reserve
+ */
+ struct GNUNET_CRYPTO_EddsaPublicKey *pub;
+
+ /**
+ * The balance amount existing in the reserve
+ */
+ struct TALER_Amount balance;
+
+ /**
+ * The expiration date of this reserve
+ */
+ struct GNUNET_TIME_Absolute expiry;
+};
+
+
+/**
+ * Information we keep for a withdrawn coin to reproduce
+ * the /withdraw operation if needed, and to have proof
+ * that a reserve was drained by this amount.
+ */
+struct CollectableBlindcoin
+{
+
+ /**
+ * Our signature over the (blinded) coin.
+ */
+ struct GNUNET_CRYPTO_rsa_Signature *sig;
+
+ /**
+ * Denomination key (which coin was generated).
+ */
+ struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub;
+
+ /**
+ * Public key of the reserve that was drained.
+ */
+ struct GNUNET_CRYPTO_EddsaPublicKey reserve_pub;
+
+ /**
+ * Hash over the blinded message, needed to verify
+ * the @e reserve_sig.
+ */
+ struct GNUNET_HashCode h_coin_envelope;
+
+ /**
+ * Signature confirming the withdrawl, matching @e reserve_pub,
+ * @e denom_pub and @e h_coin_envelope.
+ */
+ struct GNUNET_CRYPTO_EddsaSignature reserve_sig;
+};
+
+
+
+/**
+ * Types of operations on a reserved.
+ */
+enum TALER_MINT_DB_ReserveOperation
+{
+ /**
+ * Money was deposited into the reserve via a bank transfer.
+ */
+ TALER_MINT_DB_RO_BANK_TO_MINT = 0,
+
+ /**
+ * A Coin was withdrawn from the reserve using /withdraw.
+ */
+ TALER_MINT_DB_RO_WITHDRAW_COIN = 1
+};
+
+
+/**
+ * Reserve history as a linked list. Lists all of the transactions
+ * associated with this reserve (such as the bank transfers that
+ * established the reserve and all /withdraw operations we have done
+ * since).
+ */
+struct ReserveHistory
+{
+
+ /**
+ * Next entry in the reserve history.
+ */
+ struct ReserveHistory *next;
+
+ /**
+ * Type of the event, determins @e details.
+ */
+ enum TALER_MINT_DB_ReserveOperation type;
+
+ /**
+ * Details of the operation, depending on @e type.
+ */
+ union
+ {
+
+ /**
+ * Details about a bank transfer to the mint.
+ */
+ struct BankTransfer *bank;
+
+ /**
+ * Details about a /withdraw operation.
+ */
+ struct CollectableBlindcoin *withdraw;
+
+ } details;
+
+};
+
+
+/**
+ * Specification for a /deposit operation.
+ */
+struct Deposit
+{
+ /**
+ * Information about the coin that is being deposited.
+ */
+ struct TALER_CoinPublicInfo coin;
+
+ /**
+ * ECDSA signature affirming that the customer intends
+ * this coin to be deposited at the merchant identified
+ * by @e h_wire in relation to the contract identified
+ * by @e h_contract.
+ */
+ struct GNUNET_CRYPTO_EcdsaSignature csig;
+
+ /**
+ * Public key of the merchant. Enables later identification
+ * of the merchant in case of a need to rollback transactions.
+ */
+ struct GNUNET_CRYPTO_EddsaPublicKey merchant_pub;
+
+ /**
+ * Hash over the contract between merchant and customer
+ * (remains unknown to the Mint).
+ */
+ struct GNUNET_HashCode h_contract;
+
+ /**
+ * Hash of the (canonical) representation of @e wire, used
+ * to check the signature on the request. Generated by
+ * the mint from the detailed wire data provided by the
+ * merchant.
+ */
+ struct GNUNET_HashCode h_wire;
+
+ /**
+ * Detailed wire information for executing the transaction.
+ */
+ const json_t *wire;
+
+ /**
+ * Merchant-generated transaction ID to detect duplicate
+ * transactions.
+ */
+ uint64_t transaction_id;
+
+ /**
+ * Fraction of the coin's remaining value to be deposited.
+ * The coin is identified by @e coin_pub.
+ */
+ struct TALER_Amount amount;
+
+};
+
+
+/**
+ * Global information for a refreshing session. Includes
+ * dimensions of the operation, security parameters and
+ * client signatures from "/refresh/melt" and "/refresh/commit".
+ */
+struct RefreshSession
+{
+ /**
+ * Signature over the commitments by the client,
+ * only valid if @e has_commit_sig is set.
+ */
+ struct GNUNET_CRYPTO_EddsaSignature commit_sig;
+
+ /**
+ * Hash over coins to melt and coins to create of the
+ * refresh session.
+ */
+ struct GNUNET_HashCode session_hash;
+
+ /**
+ * Signature over the melt by the client.
+ */
+ struct GNUNET_CRYPTO_EddsaSignature melt_sig;
+
+ /**
+ * Number of coins we are melting.
+ */
+ uint16_t num_oldcoins;
+
+ /**
+ * Number of new coins we are creating.
+ */
+ uint16_t num_newcoins;
+
+ /**
+ * Number of parallel operations we perform for the cut and choose.
+ * (must be greater or equal to three for security). 0 if not yet
+ * known.
+ */
+ uint16_t kappa;
+
+ /**
+ * Index (smaller @e kappa) which the mint has chosen to not
+ * have revealed during cut and choose.
+ */
+ uint16_t noreveal_index;
+
+};
+
+
+/**
+ * Specification for coin in a /refresh/melt operation.
+ */
+struct RefreshMelt
+{
+ /**
+ * Information about the coin that is being melted.
+ */
+ struct TALER_CoinPublicInfo coin;
+
+ /**
+ * Signature over the melting operation.
+ */
+ struct GNUNET_CRYPTO_EcdsaSignature coin_sig;
+
+ /**
+ * Which melting operation should the coin become a part of.
+ */
+ struct GNUNET_HashCode melt_hash;
+
+ /**
+ * How much value is being 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 amount;
+
+};
+
+
+/**
+ * We have as many `struct RefreshCommitCoin` as there are new
+ * coins being created by the refresh (for each of the kappa
+ * sets). These are the coins we ask the mint to sign if the
+ * respective set is selected.
+ */
+struct RefreshCommitCoin
+{
+
+ /**
+ * Encrypted data allowing those able to decrypt it to derive
+ * the private keys of the new coins created by the refresh.
+ */
+ struct TALER_RefreshLinkEncrypted *refresh_link;
+
+ /**
+ * Blinded message to be signed (in envelope), with @e coin_env_size bytes.
+ */
+ char *coin_ev;
+
+ /**
+ * Number of bytes in @e coin_ev.
+ */
+ size_t coin_ev_size;
+
+};
+
+
+/**
+ * For each (old) coin being melted, we have a `struct
+ * RefreshCommitLink` that allows the user to find the shared secret
+ * to decrypt the respective refresh links for the new coins in the
+ * `struct RefreshCommitCoin`.
+ */
+struct RefreshCommitLink
+{
+ /**
+ * Transfer public key (FIXME: explain!)
+ */
+ struct GNUNET_CRYPTO_EcdsaPublicKey transfer_pub;
+
+ /**
+ * Encrypted shared secret to decrypt the link.
+ */
+ struct TALER_EncryptedLinkSecret shared_secret_enc;
+};
+
+
+/**
+ * Linked list of refresh information linked to a coin.
+ */
+struct LinkDataList
+{
+ /**
+ * Information is stored in a NULL-terminated linked list.
+ */
+ struct LinkDataList *next;
+
+ /**
+ * Link data, used to recover the private key of the coin
+ * by the owner of the old coin.
+ */
+ struct TALER_RefreshLinkEncrypted *link_data_enc;
+
+ /**
+ * Denomination public key, determines the value of the coin.
+ */
+ struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub;
+
+ /**
+ * Signature over the blinded envelope.
+ */
+ struct GNUNET_CRYPTO_rsa_Signature *ev_sig;
+};
+
+
+/**
+ * Specification for a /lock operation.
+ */
+struct Lock
+{
+ /**
+ * Information about the coin that is being melted.
+ */
+ struct TALER_CoinPublicInfo coin;
+
+ /**
+ * Signature over the melting operation.
+ */
+ const struct GNUNET_CRYPTO_EcdsaSignature coin_sig;
+
+ /**
+ * How much value is being melted?
+ */
+ struct TALER_Amount amount;
+
+ // FIXME: more needed...
+};
+
+
+/**
+ * Enumeration to classify the different types of transactions
+ * that can be done with a coin.
+ */
+enum TALER_MINT_DB_TransactionType
+{
+ /**
+ * /deposit operation.
+ */
+ TALER_MINT_DB_TT_DEPOSIT = 0,
+
+ /**
+ * /refresh/melt operation.
+ */
+ TALER_MINT_DB_TT_REFRESH_MELT = 1,
+
+ /**
+ * /lock operation.
+ */
+ TALER_MINT_DB_TT_LOCK = 2
+};
+
+
+/**
+ * List of transactions we performed for a particular coin.
+ */
+struct TALER_MINT_DB_TransactionList
+{
+
+ /**
+ * Next pointer in the NULL-terminated linked list.
+ */
+ struct TALER_MINT_DB_TransactionList *next;
+
+ /**
+ * Type of the transaction, determines what is stored in @e details.
+ */
+ enum TALER_MINT_DB_TransactionType type;
+
+ /**
+ * Details about the transaction, depending on @e type.
+ */
+ union
+ {
+
+ /**
+ * Details if transaction was a /deposit operation.
+ */
+ struct Deposit *deposit;
+
+ /**
+ * Details if transaction was a /refresh/melt operation.
+ */
+ struct RefreshMelt *melt;
+
+ /**
+ * Details if transaction was a /lock operation.
+ */
+ struct Lock *lock;
+
+ } details;
+
+};
+
+
+/**
+ * Handle for a database session (per-thread, for transactions).
+ */
+struct TALER_MINTDB_Session;
+
+
+/**
+ * The plugin API, returned from the plugin's "init" function.
+ * The argument given to "init" is simply a configuration handle.
+ */
+struct TALER_MINTDB_Plugin
+{
+
+ /**
+ * Closure for all callbacks.
+ */
+ void *cls;
+
+ /**
+ * Get the thread-local database-handle.
+ * Connect to the db if the connection does not exist yet.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param temporary #GNUNET_YES to use a temporary schema; #GNUNET_NO to use the
+ * database default one
+ * @param the database connection, or NULL on error
+ */
+ struct TALER_MINTDB_Session *
+ (*get_session) (void *cls,
+ int temporary);
+
+
+ /**
+ * Drop the temporary taler schema. This is only useful for testcases.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+ int
+ (*drop_temporary) (void *cls,
+ struct TALER_MINTDB_Session *db);
+
+
+ /**
+ * Create the necessary tables if they are not present
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param temporary should we use a temporary schema
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+ int
+ (*create_tables) (void *cls,
+ int temporary);
+
+
+ /**
+ * Start a transaction.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn connection to use
+ * @return #GNUNET_OK on success
+ */
+ int
+ (*start) (void *cls,
+ struct TALER_MINTDB_Session *db_conn);
+
+
+ /**
+ * Commit a transaction.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn connection to use
+ * @return #GNUNET_OK on success
+ */
+ int
+ (*commit) (void *cls,
+ struct TALER_MINTDB_Session *db_conn);
+
+
+ /**
+ * Abort/rollback a transaction.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn connection to use
+ */
+ void
+ (*rollback) (void *cls,
+ struct TALER_MINTDB_Session *db_conn);
+
+
+ /**
+ * Get the summary of a reserve.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db the database connection handle
+ * @param reserve the reserve data. The public key of the reserve should be set
+ * in this structure; it is used to query the database. The balance
+ * and expiration are then filled accordingly.
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+ int
+ (*reserve_get) (void *cls,
+ struct TALER_MINTDB_Session *db,
+ struct Reserve *reserve);
+
+ /* FIXME: add functions to add bank transfers to our DB
+ (and to test if we already did add one) (#3633/#3717) */
+
+
+ /**
+ * Insert a incoming transaction into reserves. New reserves are also created
+ * through this function.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db the database connection handle
+ * @param reserve the reserve structure. The public key of the reserve should
+ * be set here. Upon successful execution of this function, the
+ * balance and expiration of the reserve will be updated.
+ * @param balance the amount that has to be added to the reserve
+ * @param expiry the new expiration time for the reserve
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failures
+ */
+ int
+ (*reserves_in_insert) (void *cls,
+ struct TALER_MINTDB_Session *db,
+ struct Reserve *reserve,
+ const struct TALER_Amount *balance,
+ const struct GNUNET_TIME_Absolute expiry);
+
+
+ /**
+ * Locate the response for a /withdraw request under the
+ * key of the hash of the blinded message.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param h_blind hash of the blinded message
+ * @param collectable corresponding collectable coin (blind signature)
+ * if a coin is found
+ * @return #GNUNET_SYSERR on internal error
+ * #GNUNET_NO if the collectable was not found
+ * #GNUNET_YES on success
+ */
+ int
+ (*get_collectable_blindcoin) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_HashCode *h_blind,
+ struct CollectableBlindcoin *collectable);
+
+
+ /**
+ * Store collectable bit coin under the corresponding
+ * hash of the blinded message.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param h_blind hash of the blinded message
+ * @param withdraw amount by which the reserve will be withdrawn with this
+ * transaction
+ * @param collectable corresponding collectable coin (blind signature)
+ * if a coin is found
+ * @return #GNUNET_SYSERR on internal error
+ * #GNUNET_NO if the collectable was not found
+ * #GNUNET_YES on success
+ */
+ int
+ (*insert_collectable_blindcoin) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_HashCode *h_blind,
+ struct TALER_Amount withdraw,
+ const struct CollectableBlindcoin *collectable);
+
+
+ /**
+ * Get all of the transaction history associated with the specified
+ * reserve.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn connection to use
+ * @param reserve_pub public key of the reserve
+ * @return known transaction history (NULL if reserve is unknown)
+ */
+ struct ReserveHistory *
+ (*get_reserve_history) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *reserve_pub);
+
+
+ /**
+ * Check if we have the specified deposit already in the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param deposit deposit to search for
+ * @return #GNUNET_YES if we know this operation,
+ * #GNUNET_NO if this deposit is unknown to us,
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*have_deposit) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct Deposit *deposit);
+
+
+ /**
+ * Insert information about deposited coin into the
+ * database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn connection to the database
+ * @param deposit deposit information to store
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+ int
+ (*insert_deposit) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct Deposit *deposit);
+
+
+ /**
+ * Lookup refresh session data under the given public key.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database handle to use
+ * @param refresh_session_pub public key to use for the lookup
+ * @param refresh_session[OUT] where to store the result
+ * @return #GNUNET_YES on success,
+ * #GNUNET_NO if not found,
+ * #GNUNET_SYSERR on DB failure
+ */
+ int
+ (*get_refresh_session) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
+ struct RefreshSession *refresh_session);
+
+
+ /**
+ * Store new refresh session data under the given public key.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database handle to use
+ * @param refresh_session_pub public key to use to locate the session
+ * @param refresh_session session data to store
+ * @return #GNUNET_YES on success,
+ * #GNUNET_SYSERR on DB failure
+ */
+ int
+ (*create_refresh_session) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub,
+ const struct RefreshSession *refresh_session);
+
+
+
+ /**
+ * Store the given /refresh/melt request in the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param refresh_session session key of the melt operation
+ * @param oldcoin_index index of the coin to store
+ * @param melt coin melt operation details to store
+ * @return #GNUNET_OK on success
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*insert_refresh_melt) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session,
+ uint16_t oldcoin_index,
+ const struct RefreshMelt *melt);
+
+
+ /**
+ * Get information about melted coin details from the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param refresh_session session key of the melt operation
+ * @param oldcoin_index index of the coin to retrieve
+ * @param melt melt data to fill in
+ * @return #GNUNET_OK on success
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*get_refresh_melt) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session,
+ uint16_t oldcoin_index,
+ struct RefreshMelt *melt);
+
+
+ /**
+ * Store in the database which coin(s) we want to create
+ * in a given refresh operation.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param session_pub refresh session key
+ * @param newcoin_index index of the coin to generate
+ * @param denom_pub denomination of the coin to create
+ * @return #GNUNET_OK on success
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*insert_refresh_order) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub,
+ uint16_t newcoin_index,
+ const struct GNUNET_CRYPTO_rsa_PublicKey *denom_pub);
+
+
+ /**
+ * Lookup in the database the @a newcoin_index coin that we want to
+ * create in the given refresh operation.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param session_pub refresh session key
+ * @param newcoin_index index of the coin to generate
+ * @param denom_pub denomination of the coin to create
+ * @return NULL on error (not found or internal error)
+ */
+ struct GNUNET_CRYPTO_rsa_PublicKey *
+ (*get_refresh_order) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub,
+ uint16_t newcoin_index);
+
+
+ /**
+ * Store information about the commitment of the
+ * given coin for the given refresh session in the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param refresh_session_pub refresh session this commitment belongs to
+ * @param i set index (1st dimension)
+ * @param j coin index (2nd dimension), corresponds to refreshed (new) coins
+ * @param commit_coin coin commitment to store
+ * @return #GNUNET_OK on success
+ * #GNUNET_SYSERR on error
+ */
+ int
+ (*insert_refresh_commit_coin) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
+ unsigned int i,
+ unsigned int j,
+ const struct RefreshCommitCoin *commit_coin);
+
+
+ /**
+ * Obtain information about the commitment of the
+ * given coin of the given refresh session from the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param refresh_session_pub refresh session the commitment belongs to
+ * @param i set index (1st dimension)
+ * @param j coin index (2nd dimension), corresponds to refreshed (new) coins
+ * @param commit_coin[OUT] coin commitment to return
+ * @return #GNUNET_OK on success
+ * #GNUNET_NO if not found
+ * #GNUNET_SYSERR on error
+ */
+ int
+ (*get_refresh_commit_coin) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
+ unsigned int i,
+ unsigned int j,
+ struct RefreshCommitCoin *commit_coin);
+
+
+ /**
+ * Store the commitment to the given (encrypted) refresh link data
+ * for the given refresh session.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param refresh_session_pub public key of the refresh session this
+ * commitment belongs with
+ * @param i set index (1st dimension)
+ * @param j coin index (2nd dimension), corresponds to melted (old) coins
+ * @param commit_link link information to store
+ * @return #GNUNET_SYSERR on internal error, #GNUNET_OK on success
+ */
+ int
+ (*insert_refresh_commit_link) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
+ unsigned int i,
+ unsigned int j,
+ const struct RefreshCommitLink *commit_link);
+
+ /**
+ * Obtain the commited (encrypted) refresh link data
+ * for the given refresh session.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection to use
+ * @param refresh_session_pub public key of the refresh session this
+ * commitment belongs with
+ * @param i set index (1st dimension)
+ * @param j coin index (2nd dimension), corresponds to melted (old) coins
+ * @param cc[OUT] link information to return
+ * @return #GNUNET_SYSERR on internal error,
+ * #GNUNET_NO if commitment was not found
+ * #GNUNET_OK on success
+ */
+ int
+ (*get_refresh_commit_link) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *refresh_session_pub,
+ unsigned int i,
+ unsigned int j,
+ struct RefreshCommitLink *cc);
+
+
+ /**
+ * Insert signature of a new coin generated during refresh into
+ * the database indexed by the refresh session and the index
+ * of the coin. This data is later used should an old coin
+ * be used to try to obtain the private keys during "/refresh/link".
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param session_pub refresh session
+ * @param newcoin_index coin index
+ * @param ev_sig coin signature
+ * @return #GNUNET_OK on success
+ */
+ int
+ (*insert_refresh_collectable) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EddsaPublicKey *session_pub,
+ uint16_t newcoin_index,
+ const struct GNUNET_CRYPTO_rsa_Signature *ev_sig);
+
+
+ /**
+ * Obtain the link data of a coin, that is the encrypted link
+ * information, the denomination keys and the signatures.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param coin_pub public key to use to retrieve linkage data
+ * @return all known link data for the coin
+ */
+ struct LinkDataList *
+ (*get_link) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EcdsaPublicKey *coin_pub);
+
+
+ /**
+ * Obtain shared secret and transfer public key from the public key of
+ * the coin. This information and the link information returned by
+ * #TALER_db_get_link() enable the owner of an old coin to determine
+ * the private keys of the new coins after the melt.
+ *
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param coin_pub public key of the coin
+ * @param transfer_pub[OUT] public transfer key
+ * @param shared_secret_enc[OUT] set to shared secret
+ * @return #GNUNET_OK on success,
+ * #GNUNET_NO on failure (not found)
+ * #GNUNET_SYSERR on internal failure (database issue)
+ */
+ int
+ (*get_transfer) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EcdsaPublicKey *coin_pub,
+ struct GNUNET_CRYPTO_EcdsaPublicKey *transfer_pub,
+ struct TALER_EncryptedLinkSecret *shared_secret_enc);
+
+
+ /**
+ * Test if the given /lock request is known to us.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param lock lock operation
+ * @return #GNUNET_YES if known,
+ * #GNUENT_NO if not,
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*have_lock) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct Lock *lock);
+
+
+ /**
+ * Store the given /lock request in the database.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param lock lock operation
+ * @return #GNUNET_OK on success
+ * #GNUNET_SYSERR on internal error
+ */
+ int
+ (*insert_lock) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct Lock *lock);
+
+
+ /**
+ * Compile a list of all (historic) transactions performed
+ * with the given coin (/refresh/melt and /deposit operations).
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param db_conn database connection
+ * @param coin_pub coin to investigate
+ * @return list of transactions, NULL if coin is fresh
+ */
+ struct TALER_MINT_DB_TransactionList *
+ (*get_coin_transactions) (void *cls,
+ struct TALER_MINTDB_Session *db_conn,
+ const struct GNUNET_CRYPTO_EcdsaPublicKey *coin_pub);
+
+};
+
+
+#endif /* _NEURO_MINT_DB_H */