/*
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 <http://www.gnu.org/licenses/>
*/
/**
* @file include/taler_util.h
* @brief Interface for common utility functions
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
*/
#ifndef TALER_UTIL_H
#define TALER_UTIL_H
#define __TALER_UTIL_LIB_H_INSIDE__
#include <gnunet/gnunet_util_lib.h>
#include <microhttpd.h>
#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 returns the age group of a given age for a given age mask
*
* @param mask Age mask
* @param age The given age
* @return age group
*/
uint8_t
TALER_get_age_group (
const struct TALER_AgeMask *mask,
uint8_t age);
/**
* @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);
/* @brief Return the lowest age in the corresponding group for a given age
* according the given age mask.
*
* @param[IN] mask age mask
* @param[IN] age age to check
* @return lowest age in corresponding age group
*/
uint8_t
TALER_get_lowest_age (
const struct TALER_AgeMask *mask,
uint8_t age);
/**
* 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