/* This file is part of TALER Copyright (C) 2014-2023 Taler Systems SA 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, see */ /** * @file include/taler_util.h * @brief Interface for common utility functions * @author Sree Harsha Totakura */ #ifndef TALER_UTIL_H #define TALER_UTIL_H #define __TALER_UTIL_LIB_H_INSIDE__ #include #include #include "taler_amount_lib.h" #include "taler_crypto_lib.h" /** * Version of the Taler API, in hex. * Thus 0.8.4-1 = 0x00080401. */ #define TALER_API_VERSION 0x00090200 /** * Stringify operator. * * @param a some expression to stringify. Must NOT be a macro. * @return same expression as a constant string. */ #define TALER_S(a) #a /** * Stringify operator. * * @param a some expression to stringify. Can be a macro. * @return macro-expanded expression as a constant string. */ #define TALER_QUOTE(a) TALER_S (a) /* Define logging functions */ #define TALER_LOG_DEBUG(...) \ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, __VA_ARGS__) #define TALER_LOG_INFO(...) \ GNUNET_log (GNUNET_ERROR_TYPE_INFO, __VA_ARGS__) #define TALER_LOG_WARNING(...) \ GNUNET_log (GNUNET_ERROR_TYPE_WARNING, __VA_ARGS__) #define TALER_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; \ TALER_LOG_ERROR ("%s at %s:%d\n", reason, __FILE__, __LINE__); \ abort (); \ } while (0) /** * HTTP header with an AML officer signature to approve the inquiry. * Used only in GET Requests. */ #define TALER_AML_OFFICER_SIGNATURE_HEADER "Taler-AML-Officer-Signature" /** * 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 TALER_LOG_GCRY_ERROR(cmd, rc) do { TALER_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; \ TALER_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); /** * Convert a buffer to an 8-character string * representative of the contents. This is used * for logging binary data when debugging. * * @param buf buffer to log * @param buf_size number of bytes in @a buf * @return text representation of buf, valid until next * call to this function */ const char * TALER_b2s (const void *buf, size_t buf_size); /** * Convert a fixed-sized object to a string using * #TALER_b2s(). * * @param obj address of object to convert * @return string representing the binary obj buffer */ #define TALER_B2S(obj) TALER_b2s ((obj), sizeof (*(obj))) /** * Obtain denomination amount from configuration file. * * @param cfg configuration to extract data from * @param section section of the configuration to access * @param option option of the configuration to access * @param[out] denom set to the amount found in configuration * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ enum GNUNET_GenericReturnValue TALER_config_get_amount (const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, struct TALER_Amount *denom); /** * Obtain denomination fee structure of a * denomination from configuration file. All * fee options must start with "fee_" and have * names typical for the respective fees. * * @param cfg configuration to extract data from * @param currency expected currency * @param section section of the configuration to access * @param[out] fees set to the denomination fees * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ enum GNUNET_GenericReturnValue TALER_config_get_denom_fees (const struct GNUNET_CONFIGURATION_Handle *cfg, const char *currency, const char *section, struct TALER_DenomFeeSet *fees); /** * Check that all denominations in @a fees use * @a currency * * @param currency desired currency * @param fees fee set to check * @return #GNUNET_OK on success */ enum GNUNET_GenericReturnValue TALER_denom_fee_check_currency ( const char *currency, const struct TALER_DenomFeeSet *fees); /** * Load our currency from the @a cfg (in section [taler] * the option "CURRENCY"). * * @param cfg configuration to use * @param[out] currency where to write the result * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure */ enum GNUNET_GenericReturnValue TALER_config_get_currency (const struct GNUNET_CONFIGURATION_Handle *cfg, char **currency); /** * Allow user to specify an amount on the command line. * * @param shortName short name of the option * @param name long name of the option * @param argumentHelp help text for the option argument * @param description long help text for the option * @param[out] amount set to the amount specified at the command line */ struct GNUNET_GETOPT_CommandLineOption TALER_getopt_get_amount (char shortName, const char *name, const char *argumentHelp, const char *description, struct TALER_Amount *amount); /** * Return default project data used by Taler. */ const struct GNUNET_OS_ProjectData * TALER_project_data_default (void); /** * Initialize libtalerutil. */ void TALER_OS_init (void); /** * Re-encode string at @a inp to match RFC 8785 (section 3.2.2.2). * * @param[in,out] inp pointer to string to re-encode * @return number of bytes in resulting @a inp */ size_t TALER_rfc8785encode (char **inp); /** * URL-encode a string according to rfc3986. * * @param s string to encode * @returns the urlencoded string, the caller must free it with GNUNET_free() */ char * TALER_urlencode (const char *s); /** * Test if all characters in @a url are valid for * a URL. * * @param url URL to sanity-check * @return true if @a url only contains valid characters */ bool TALER_url_valid_charset (const char *url); /** * Check if @a lang matches the @a language_pattern, and if so with * which preference. * See also: https://tools.ietf.org/html/rfc7231#section-5.3.1 * * @param language_pattern a language preferences string * like "fr-CH, fr;q=0.9, en;q=0.8, *;q=0.1" * @param lang the 2-digit language to match * @return q-weight given for @a lang in @a language_pattern, 1.0 if no weights are given; * 0 if @a lang is not in @a language_pattern */ double TALER_language_matches (const char *language_pattern, const char *lang); /** * Find out if an MHD connection is using HTTPS (either * directly or via proxy). * * @param connection MHD connection * @returns #GNUNET_YES if the MHD connection is using https, * #GNUNET_NO if the MHD connection is using http, * #GNUNET_SYSERR if the connection type couldn't be determined */ enum GNUNET_GenericReturnValue TALER_mhd_is_https (struct MHD_Connection *connection); /** * Make an absolute URL with query parameters. * * If a 'value' is given as NULL, both the key and the value are skipped. Note * that a NULL value does not terminate the list, only a NULL key signals the * end of the list of arguments. * * @param base_url absolute base URL to use * @param path path of the url * @param ... NULL-terminated key-value pairs (char *) for query parameters, * only the value will be url-encoded * @returns the URL, must be freed with #GNUNET_free */ char * TALER_url_join (const char *base_url, const char *path, ...); /** * Make an absolute URL for the given parameters. * * If a 'value' is given as NULL, both the key and the value are skipped. Note * that a NULL value does not terminate the list, only a NULL key signals the * end of the list of arguments. * * @param proto protocol for the URL (typically https) * @param host hostname for the URL * @param prefix prefix for the URL * @param path path for the URL * @param ... NULL-terminated key-value pairs (char *) for query parameters, * the value will be url-encoded * @returns the URL, must be freed with #GNUNET_free */ char * TALER_url_absolute_raw (const char *proto, const char *host, const char *prefix, const char *path, ...); /** * Make an absolute URL for the given parameters. * * If a 'value' is given as NULL, both the key and the value are skipped. Note * that a NULL value does not terminate the list, only a NULL key signals the * end of the list of arguments. * * @param proto protocol for the URL (typically https) * @param host hostname for the URL * @param prefix prefix for the URL * @param path path for the URL * @param args NULL-terminated key-value pairs (char *) for query parameters, * the value will be url-encoded * @returns the URL, must be freed with #GNUNET_free */ char * TALER_url_absolute_raw_va (const char *proto, const char *host, const char *prefix, const char *path, va_list args); /** * Make an absolute URL for a given MHD connection. * * @param connection the connection to get the URL for * @param path path of the url * @param ... NULL-terminated key-value pairs (char *) for query parameters, * the value will be url-encoded * @returns the URL, must be freed with #GNUNET_free */ char * TALER_url_absolute_mhd (struct MHD_Connection *connection, const char *path, ...); /** * Obtain the payment method from a @a payto_uri * * @param payto_uri the URL to parse * @return NULL on error (malformed @a payto_uri) */ char * TALER_payto_get_method (const char *payto_uri); /** * Obtain the account name from a payto URL. * * @param payto an x-taler-bank payto URL * @return only the account name from the @a payto URL, NULL if not an x-taler-bank * payto URL */ char * TALER_xtalerbank_account_from_payto (const char *payto); /** * Obtain the receiver name from a payto URL. * * @param payto an x-taler-bank payto URL * @return only the receiver name from the @a payto URL, NULL if not an x-taler-bank payto URL */ char * TALER_payto_get_receiver_name (const char *payto); /** * Extract the subject value from the URI parameters. * * @param payto_uri the URL to parse * @return NULL if the subject parameter is not found. * The caller should free the returned value. */ char * TALER_payto_get_subject (const char *payto_uri); /** * Check that a payto:// URI is well-formed. * * @param payto_uri the URL to check * @return NULL on success, otherwise an error * message to be freed by the caller! */ char * TALER_payto_validate (const char *payto_uri); /** * Create payto://-URI for a given exchange base URL * and a @a reserve_pub. * * @param exchange_url the base URL of the exchange * @param reserve_pub the public key of the reserve * @return payto://-URI for the reserve (without receiver-name!) */ char * TALER_reserve_make_payto (const char *exchange_url, const struct TALER_ReservePublicKeyP *reserve_pub); /** * Check that an IBAN number is well-formed. * * Validates given IBAN according to the European Banking Standards. See: * http://www.europeanpaymentscouncil.eu/documents/ECBS%20IBAN%20standard%20EBS204_V3.2.pdf * * @param iban the IBAN to check * @return NULL on success, otherwise an error * message to be freed by the caller! */ char * TALER_iban_validate (const char *iban); /** * Possible values for a binary filter. */ enum TALER_EXCHANGE_YesNoAll { /** * If condition is yes. */ TALER_EXCHANGE_YNA_YES = 1, /** * If condition is no. */ TALER_EXCHANGE_YNA_NO = 2, /** * Condition disabled. */ TALER_EXCHANGE_YNA_ALL = 3 }; /** * Convert query argument to @a yna value. * * @param connection connection to take query argument from * @param arg argument to try for * @param default_val value to assign if the argument is not present * @param[out] yna value to set * @return true on success, false if the parameter was malformed */ bool TALER_arg_to_yna (struct MHD_Connection *connection, const char *arg, enum TALER_EXCHANGE_YesNoAll default_val, enum TALER_EXCHANGE_YesNoAll *yna); /** * Convert YNA value to a string. * * @param yna value to convert * @return string representation ("yes"/"no"/"all"). */ const char * TALER_yna_to_string (enum TALER_EXCHANGE_YesNoAll yna); #ifdef __APPLE__ /** * Returns the first occurrence of `c` in `s`, or returns the null-byte * terminating the string if it does not occur. * * @param s the string to search in * @param c the character to search for * @return char* the first occurrence of `c` in `s` */ char *strchrnul (const char *s, int c); #endif /** * @brief Parses a string as a list of age groups. * * The string must consist of a colon-separated list of increasing integers * between 0 and 31. Each entry represents the beginning of a new age group. * F.e. the string * * "8:10:12:14:16:18:21" * * represents the following list of eight age groups: * * | Group | Ages | * | -----:|:------------- | * | 0 | 0, 1, ..., 7 | * | 1 | 8, 9 | * | 2 | 10, 11 | * | 3 | 12, 13 | * | 4 | 14, 15 | * | 5 | 16, 17 | * | 6 | 18, 19, 20 | * | 7 | 21, ... | * * which is then encoded as a bit mask with the corresponding bits set: * * 31 24 16 8 0 * | | | | | * oooooooo oo1oo1o1 o1o1o1o1 ooooooo1 * * @param groups String representation of age groups * @param[out] mask Mask representation for age restriction. * @return Error, if age groups were invalid, OK otherwise. */ enum GNUNET_GenericReturnValue TALER_parse_age_group_string ( const char *groups, struct TALER_AgeMask *mask); /** * @brief Encodes the age mask into a string, like "8:10:12:14:16:18:21" * * @param mask Age mask * @return String representation of the age mask, allocated by GNUNET_malloc. * Can be used as value in the TALER config. */ char * TALER_age_mask_to_string ( const struct TALER_AgeMask *mask); /** * @brief Parses a JSON object { "age_groups": "a:b:...y:z" }. * * @param root is the json object * @param[out] mask on success, will contain the age mask * @return #GNUNET_OK on success and #GNUNET_SYSERR on failure. */ enum GNUNET_GenericReturnValue TALER_JSON_parse_age_groups (const json_t *root, struct TALER_AgeMask *mask); /** * Handle to an external process that will assist * with some JSON-to-JSON conversion. */ struct TALER_JSON_ExternalConversion; /** * Type of a callback that receives a JSON @a result. * * @param cls closure * @param status_type how did the process die * @param code termination status code from the process * @param result some JSON result, NULL if we failed to get an JSON output */ typedef void (*TALER_JSON_JsonCallback) (void *cls, enum GNUNET_OS_ProcessStatusType status_type, unsigned long code, const json_t *result); /** * Launch some external helper @a binary to convert some @a input * and eventually call @a cb with the result. * * @param input JSON to serialize and pass to the helper process * @param cb function to call on the result * @param cb_cls closure for @a cb * @param binary name of the binary to execute * @param ... NULL-terminated list of arguments for the @a binary, * usually starting with again the name of the binary * @return handle to cancel the operation (and kill the helper) */ struct TALER_JSON_ExternalConversion * TALER_JSON_external_conversion_start (const json_t *input, TALER_JSON_JsonCallback cb, void *cb_cls, const char *binary, ...); /** * Abort external conversion, killing the process and preventing * the callback from being called. Must not be called after the * callback was invoked. * * @param[in] ec external conversion handle to cancel */ void TALER_JSON_external_conversion_stop ( struct TALER_JSON_ExternalConversion *ec); #undef __TALER_UTIL_LIB_H_INSIDE__ #endif