/*
This file is part of TALER
Copyright (C) 2014-2021 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_extensions.h
* @brief Interface for extensions
* @author Özgür Kesim
*/
#ifndef TALER_EXTENSIONS_H
#define TALER_EXTENSIONS_H
#include
#include "taler_crypto_lib.h"
#include "taler_json_lib.h"
#define TALER_EXTENSION_SECTION_PREFIX "exchange-extension-"
enum TALER_Extension_Type
{
TALER_Extension_AgeRestriction = 0,
TALER_Extension_MaxPredefined = 1 // Must be last of the predefined
};
/*
* Represents the implementation of an extension.
* TODO: add documentation
*/
struct TALER_Extension
{
/* simple linked list */
struct TALER_Extension *next;
enum TALER_Extension_Type type;
char *name;
bool critical;
char *version;
void *config;
json_t *config_json;
void (*disable)(struct TALER_Extension *this);
enum GNUNET_GenericReturnValue (*test_json_config)(
const json_t *config);
enum GNUNET_GenericReturnValue (*load_json_config)(
struct TALER_Extension *this,
json_t *config);
json_t *(*config_to_json)(
const struct TALER_Extension *this);
enum GNUNET_GenericReturnValue (*load_taler_config)(
struct TALER_Extension *this,
const struct GNUNET_CONFIGURATION_Handle *cfg);
};
/**
* Generic functions for extensions
*/
void
TALER_extensions_init ();
/*
* Sets the configuration of the extensions from the given TALER configuration
*
* @param cfg Handle to the TALER configuration
* @return GNUNET_OK on success, GNUNET_SYSERR if unknown extensions were found
* or any particular configuration couldn't be parsed.
*/
enum GNUNET_GenericReturnValue
TALER_extensions_load_taler_config (
const struct GNUNET_CONFIGURATION_Handle *cfg);
/*
* Check the given obj to be a valid extension object and fill the fields
* accordingly.
*/
enum GNUNET_GenericReturnValue
TALER_extensions_is_json_config (
json_t *obj,
int *critical,
const char **version,
json_t **config);
/*
* Sets the configuration of the extensions from a given JSON object.
*
* he JSON object must be of type ExchangeKeysResponse as described in
* https://docs.taler.net/design-documents/006-extensions.html#exchange
*
* @param cfg JSON object containting the configuration for all extensions
* @return GNUNET_OK on success, GNUNET_SYSERR if unknown extensions were found
* or any particular configuration couldn't be parsed.
*/
enum GNUNET_GenericReturnValue
TALER_extensions_load_json_config (
json_t *cfg);
/*
* Returns the head of the linked list of extensions
*/
const struct TALER_Extension *
TALER_extensions_get_head ();
/*
* Adds an extension to the linked list of extensions
*
* @param new_extension the new extension to be added
* @return GNUNET_OK on success, GNUNET_SYSERR if the extension is invalid
* (missing fields), GNUNET_NO if there is already an extension with that name
* or type.
*/
enum GNUNET_GenericReturnValue
TALER_extensions_add (
const struct TALER_Extension *new_extension);
/**
* Finds and returns a supported extension by a given type.
*
* @param type type of the extension to lookup
* @return extension found, or NULL (should not happen!)
*/
const struct TALER_Extension *
TALER_extensions_get_by_type (
enum TALER_Extension_Type type);
/**
* Finds and returns a supported extension by a given name.
*
* @param name name of the extension to lookup
* @return the extension, if found, NULL otherwise
*/
const struct TALER_Extension *
TALER_extensions_get_by_name (
const char *name);
#define TALER_extensions_is_enabled(ext) (NULL != (ext)->config)
/**
* Check if a given type of an extension is enabled
*
* @param type type of to check
* @return true enabled, false if not enabled, will assert if type is not found.
*/
bool
TALER_extensions_is_enabled_type (
enum TALER_Extension_Type type);
/*
* Verify the signature of a given JSON object for extensions with the master
* key of the exchange.
*
* The JSON object must be of type ExchangeKeysResponse as described in
* https://docs.taler.net/design-documents/006-extensions.html#exchange
*
* @param extensions JSON object with the extension configuration
* @param extensions_sig signature of the hash of the JSON object
* @param master_pub public key to verify the signature
* @return GNUNET_OK on success, GNUNET_SYSERR when hashing of the JSON fails
* and GNUNET_NO if the signature couldn't be verified.
*/
enum GNUNET_GenericReturnValue
TALER_extensions_verify_json_config_signature (
json_t *extensions,
struct TALER_MasterSignatureP *extensions_sig,
struct TALER_MasterPublicKeyP *master_pub);
/*
* TALER Age Restriction Extension
*/
#define TALER_EXTENSION_SECTION_AGE_RESTRICTION (TALER_EXTENSION_SECTION_PREFIX \
"age_restriction")
/**
* The default age mask represents the age groups
* 0-7, 8-9, 10-11, 12-13, 14-15, 16-17, 18-20, 21-...
*/
#define TALER_EXTENSION_AGE_RESTRICTION_DEFAULT_AGE_MASK (1 | 1 << 8 | 1 << 10 \
| 1 << 12 | 1 << 14 \
| 1 << 16 | 1 << 18 \
| 1 << 21)
#define TALER_EXTENSION_AGE_RESTRICTION_DEFAULT_AGE_GROUPS "8:10:12:14:16:18:21"
/**
* @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" parses into the following list of age
* groups
* 0-7, 8-9, 10-11, 12-13, 14-15, 16-17, 18-20, 21-...
* which then is represented as 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);
/**
* 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);
/**
* Returns true when age restriction is configured and enabled.
*/
bool
TALER_extensions_age_restriction_is_enabled ();
/**
* Returns true when age restriction is configured (might not be _enabled_,
* though).
*/
bool
TALER_extensions_age_restriction_is_configured ();
/**
* Returns the currently set age mask. Note that even if age restriction is
* not enabled, the age mask might be have a non-zero value.
*/
struct TALER_AgeMask
TALER_extensions_age_restriction_ageMask ();
/**
* Returns the amount of age groups defined. 0 means no age restriction
* enabled.
*/
size_t
TALER_extensions_age_restriction_num_groups ();
/**
* Parses a JSON object { "age_groups": "a:b:...y:z" }.
*
* @param root is the json object
* @param[out] mask on succes, 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);
/*
* TODO: Add Peer2Peer Extension
*/
#endif