/* This file is part of TALER (C) 2014 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 include/taler_util.h * @brief Interface for common utility functions * @author Sree Harsha Totakura */ #ifndef UTIL_H_ #define UTIL_H_ #include #include /* Define logging functions */ #define LOG_DEBUG(...) \ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, __VA_ARGS__) #define LOG_WARNING(...) \ GNUNET_log (GNUNET_ERROR_TYPE_WARNING, __VA_ARGS__) #define LOG_ERROR(...) \ GNUNET_log (GNUNET_ERROR_TYPE_ERROR, __VA_ARGS__) /** * Tests a given as assertion and if failed prints it as a warning with the * given reason * * @param EXP the expression to test as assertion * @param reason string to print as warning */ #define TALER_assert_as(EXP, reason) \ do { \ if (EXP) break; \ LOG_ERROR("%s at %s:%d\n", reason, __FILE__, __LINE__); \ abort(); \ } while(0) /** * Log an error message at log-level 'level' that indicates * a failure of the command 'cmd' with the message given * by gcry_strerror(rc). */ #define LOG_GCRY_ERROR(cmd, rc) do { LOG_ERROR("`%s' failed at %s:%d with error: %s\n", cmd, __FILE__, __LINE__, gcry_strerror(rc)); } while(0) #define TALER_gcry_ok(cmd) \ do {int rc; rc = cmd; if (!rc) break; LOG_ERROR("A Gcrypt call failed at %s:%d with error: %s\n", __FILE__, __LINE__, gcry_strerror(rc)); abort(); } while (0) /** * Initialize Gcrypt library. */ void TALER_gcrypt_init (void); /* *********************** Amount management ****************** */ /** * Number of characters (plus 1 for 0-termination) we use to * represent currency names (i.e. EUR, USD, etc.). */ #define TALER_CURRENCY_LEN 4 GNUNET_NETWORK_STRUCT_BEGIN /** * Amount, encoded for network transmission. */ struct TALER_AmountNBO { /** * Value in the main currency, in NBO. */ uint32_t value; /** * Additinal fractional value, in NBO. */ uint32_t fraction; /** * Type of the currency being represented. */ char currency[TALER_CURRENCY_LEN]; }; GNUNET_NETWORK_STRUCT_END /** * Representation of monetary value in a given currency. */ struct TALER_Amount { /** * Value (numerator of fraction) */ uint32_t value; /** * Fraction (denominator of fraction) */ uint32_t fraction; /** * Currency string, left adjusted and padded with zeros. */ char currency[4]; }; /** * Parse denomination description, in the format "T : V : F". * * @param str denomination description * @param denom denomination to write the result to * @return #GNUNET_OK if the string is a valid denomination specification, * #GNUNET_SYSERR if it is invalid. */ int TALER_string_to_amount (const char *str, struct TALER_Amount *denom); /** * Convert amount from host to network representation. * * @param d amount in host representation * @return amount in network representation */ struct TALER_AmountNBO TALER_amount_hton (struct TALER_Amount d); /** * Convert amount from network to host representation. * * @param d amount in network representation * @return amount in host representation */ struct TALER_Amount TALER_amount_ntoh (struct TALER_AmountNBO dn); /** * Compare the value/fraction of two amounts. Does not compare the currency, * i.e. comparing amounts with the same value and fraction but different * currency would return 0. * * @param a1 first amount * @param a2 second amount * @return result of the comparison */ int TALER_amount_cmp (struct TALER_Amount a1, struct TALER_Amount a2); /** * Perform saturating subtraction of amounts. * * @param a1 amount to subtract from * @param a2 amount to subtract * @return (a1-a2) or 0 if a2>=a1 */ struct TALER_Amount TALER_amount_subtract (struct TALER_Amount a1, struct TALER_Amount a2); /** * Perform saturating addition of amounts * * @param a1 first amount to add * @param a2 second amount to add * @return sum of a1 and a2 */ struct TALER_Amount TALER_amount_add (struct TALER_Amount a1, struct TALER_Amount a2); /** * Normalize the given amount. * * @param amout amount to normalize * @return normalized amount */ struct TALER_Amount TALER_amount_normalize (struct TALER_Amount amount); /** * Convert amount to string. * * @param amount amount to convert to string * @return freshly allocated string representation */ char * TALER_amount_to_string (struct TALER_Amount amount); /* ****************** FIXME: move to GNUnet? ************** */ /** * Return the base32crockford encoding of the given buffer. * * The returned string will be freshly allocated, and must be free'd * with #GNUNET_free(). * * @param buffer with data * @param size size of the buffer * @return freshly allocated, null-terminated string */ char * TALER_data_to_string_alloc (const void *buf, size_t size); /* ****************** Refresh crypto primitives ************* */ /** * Representation of an encrypted refresh link. */ struct TALER_RefreshLinkEncrypted { /** * Encrypted blinding key with @e blinding_key_enc_size bytes, * must be allocated at the end of this struct. */ const char *blinding_key_enc; /** * Number of bytes in @e blinding_key_enc. */ size_t blinding_key_enc_size; /** * Encrypted private key of the coin. */ char coin_priv_enc[sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey)]; }; /** * Representation of an refresh link in cleartext. */ struct TALER_RefreshLinkDecrypted { /** * Private key of the coin. */ struct GNUNET_CRYPTO_EcdsaPrivateKey coin_priv; /** * Blinding key with @e blinding_key_enc_size bytes. */ struct GNUNET_CRYPTO_rsa_BlindingKey *blinding_key; }; /** * Decrypt refresh link information. * * @param input encrypted refresh link data * @param secret shared secret to use for decryption * @return NULL on error */ struct TALER_RefreshLinkDecrypted * TALER_refresh_decrypt (const struct TALER_RefreshLinkEncrypted *input, const struct GNUNET_HashCode *secret); /** * Encrypt refresh link information. * * @param input plaintext refresh link data * @param secret shared secret to use for encryption * @return NULL on error (should never happen) */ struct TALER_RefreshLinkEncrypted * TALER_refresh_encrypt (const struct TALER_RefreshLinkDecrypted *input, const struct GNUNET_HashCode *secret); #endif