diff options
Diffstat (limited to 'src/include/taler_extensions.h')
| -rw-r--r-- | src/include/taler_extensions.h | 384 |
1 files changed, 265 insertions, 119 deletions
diff --git a/src/include/taler_extensions.h b/src/include/taler_extensions.h index 8e1823cc..d76de25e 100644 --- a/src/include/taler_extensions.h +++ b/src/include/taler_extensions.h @@ -24,119 +24,254 @@ #include <gnunet/gnunet_util_lib.h> #include "taler_crypto_lib.h" #include "taler_json_lib.h" +#include "taler_mhd_lib.h" +#include "taler_exchangedb_plugin.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 + TALER_Extension_PolicyNull = 0, + + TALER_Extension_AgeRestriction = 1, + TALER_Extension_PolicyMerchantRefund = 2, + TALER_Extension_PolicyBrandtVickeryAuction = 3, + TALER_Extension_PolicyEscrowedPayment = 4, + + TALER_Extension_MaxPredefined = 5 // Must be last of the predefined +}; + + +/* + * @brief simply linked list of extensions + */ + +struct TALER_Extensions +{ + struct TALER_Extensions *next; + const struct TALER_Extension *extension; +}; + +/* + * @brief Serial ID under which the policy details to an deposit are stored in + * the policy_details table. + */ +struct TALER_ExtensionsPolicySerialID +{ + struct GNUNET_HashCode hash; }; /* * @brief Represents the implementation of an extension. * - * TODO: add documentation + * An "Extension" is an optional feature for the Exchange. + * There are only two types of extensions: + * + * a) Age restriction: This is a special feature that directly interacts with + * denominations and coins, but is not define policies during deposits, see b). + * The implementation of this extension doesn't have to implement any of the + * http- or depost-handlers in the struct. + * + * b) Policies for deposits: These are extensions that define policies (such + * as refund, escrow or auctions) for deposit requests. These extensions have + * to implement at least the deposit- and post-http-handler in the struct to be + * functional. + * + * In addition to the handlers defined in this struct, an extension must also + * be a plugin in the GNUNET_Plugin sense. That is, it must implement the + * functions + * 1: (void *ext)libtaler_extension_<name>_init(void *cfg) + * and + * 2: (void *)libtaler_extension_<name>_done(void *) + * + * In 1:, the input will be the GNUNET_CONFIGURATION_Handle to the TALER + * configuration and the output must be the struct TALER_Extension * on + * success, NULL otherwise. + * + * In 2:, no arguments are passed and NULL is expected to be returned. */ struct TALER_Extension { - /* simple linked list */ - struct TALER_Extension *next; - + /** + * Type of the extension. Only one extension of a type can be loaded + * at any time. + */ enum TALER_Extension_Type type; + + /** + * The name of the extension, must be unique among all loaded extensions. It + * is used in URLs for /extension/$NAME as well. + */ char *name; + + /** + * Criticality of the extension. It has the same semantics as "critical" has + * for extensions in X.509: + * - if "true", the client must "understand" the extension before proceeding, + * - if "false", clients can safely skip extensions they do not understand. + * (see https://datatracker.ietf.org/doc/html/rfc5280#section-4.2) + */ bool critical; + + /** + * Version of the extension must be provided in Taler's protocol verison ranges notation, see + * https://docs.taler.net/core/api-common.html#protocol-version-ranges + */ char *version; + + /** + * If the extension is marked as enabled, it will be listed in the + * "extensions" field in the "/keys" response. + */ + bool enabled; + + /** + * Opaque (public) configuration object, set by the extension. + */ void *config; - json_t *config_json; - void (*disable)(struct TALER_Extension *ext); - enum GNUNET_GenericReturnValue (*test_json_config)( - const json_t *config); + /** + * @brief Handler to to disable the extension. + * + * @param ext The current extension object + */ + void (*disable)(struct TALER_Extension *ext); - enum GNUNET_GenericReturnValue (*load_json_config)( + /** + * @brief Handler to read an extension-specific configuration in JSON + * encoding and enable the extension. Must be implemented by the extension. + * + * @param ext The extension object. If NULL, the configuration will only be checked. + * @param config A JSON blob + * @return GNUNET_OK if the json was a valid configuration for the extension. + */ + enum GNUNET_GenericReturnValue (*load_config)( struct TALER_Extension *ext, json_t *config); - json_t *(*config_to_json)( + /** + * @brief Handler to return the manifest of the extension in JSON encoding. + * + * See + * https://docs.taler.net/design-documents/006-extensions.html#tsref-type-Extension + * for the definition. + * + * @param ext The extension object + * @return The JSON encoding of the extension, if enabled, NULL otherwise. + */ + json_t *(*manifest)( const struct TALER_Extension *ext); - enum GNUNET_GenericReturnValue (*load_taler_config)( - struct TALER_Extension *ext, - const struct GNUNET_CONFIGURATION_Handle *cfg); + /* ========================= + * Policy related handlers + * ========================= + */ + /** + * @brief Handler to check a policy. Can be NULL; + * + * When a deposit request refers to this extension in its policy + * (see https://docs.taler.net/core/api-exchange.html#deposit), this handler + * will be called before the deposit transaction. + * + * @param[in] policy_details Details about the policy, provided by the client + * during a deposit request. + * @param[out] serial On success, will contain the serial-ID under which the + * exchange should save the policy_details in the deposit table. + * @param[out] deadline On sucess, set to the deadline until the policy must + * be fulfilled. Might be "forever". This value is used by an external + * mechanism to detect timeouts. + * @return GNUNET_OK if the data was accepted by the extension. + */ + enum GNUNET_GenericReturnValue (*parse_policy_details)( + const json_t *policy_details, + struct TALER_ExtensionsPolicySerialID *serial, + struct GNUNET_TIME_Timestamp *deadline); + + /** + * @brief Handler for POST-requests to the /policy/$name endpoint. Can be NULL. + * + * @param connection The current connection + * @param root The JSON body from the request + * @param args Additional query parameters of the request. + * @return MDH result + */ + MHD_RESULT (*http_post_handler)( + struct MHD_Connection *connection, + const json_t *root, + const char *const args[]); + + /** + * @brief Handler for GET-requests to the /policy/$name endpoint. Can be NULL. + * + * @param connection The current connection + * @param root The JSON body from the request + * @param args Additional query parameters of the request. + * @return MDH result + */ + MHD_RESULT (*http_get_handler)( + struct MHD_Connection *connection, + const char *const args[]); }; + /** * Generic functions for extensions */ /* - * @brief Sets the configuration of the extensions from the given TALER - * configuration. + * @brief Loads the extensions as shared libraries, as specified in 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 ( +TALER_extensions_init ( const struct GNUNET_CONFIGURATION_Handle *cfg); /* - * @brief Checks the given obj to be a valid extension object and fill the - * fields accordingly. + * @brief Parses a given JSON object as an extension manifest. * - * @param[in] obj Object to verify is a valid extension + * @param[in] obj JSON object to parse as an extension manifest * @param{out] critical will be set to 1 if the extension is critical according to obj * @param[out] version will be set to the version of the extension according to obj * @param[out] config will be set to the configuration of the extension according to obj * @return OK on success, Error otherwise */ enum GNUNET_GenericReturnValue -TALER_extensions_is_json_config ( +TALER_extensions_parse_manifest ( json_t *obj, int *critical, const char **version, json_t **config); /* - * @brief Sets the configuration of the extensions from a given JSON object. + * @brief Loads extensions according to the manifests. * - * The JSON object must be of type ExchangeKeysResponse as described in - * https://docs.taler.net/design-documents/006-extensions.html#exchange + * The JSON object must be of type ExtensionsManifestsResponse as described + * in https://docs.taler.net/design-documents/006-extensions.html#exchange * - * @param cfg JSON object containing the configuration for all extensions + * @param cfg JSON object containing the manifests 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); +TALER_extensions_load_manifests ( + json_t *manifests); /* * @brief Returns the head of the linked list of extensions. */ -const struct TALER_Extension * +const struct TALER_Extensions * TALER_extensions_get_head (); -/* - * @brief 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 ( - struct TALER_Extension *new_extension); - /** * @brief Finds and returns a supported extension by a given type. * - * @param type type of the extension to lookup + * @param type of the extension to lookup * @return extension found, or NULL (should not happen!) */ const struct TALER_Extension * @@ -154,8 +289,6 @@ const struct TALER_Extension * TALER_extensions_get_by_name ( const char *name); -#define TALER_extensions_is_enabled(ext) (NULL != (ext)->config) - /** * @brief Check if a given type of an extension is enabled * @@ -166,12 +299,21 @@ bool TALER_extensions_is_enabled_type ( enum TALER_Extension_Type type); +/** + * @brief Check if an extension is enabled + * + * @param extension The extension handler. + * @return true enabled, false if not enabled, will assert if type is not found. + */ +bool +TALER_extensions_is_enabled ( + const struct TALER_Extension *extension); /* * 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 + * The JSON object must be of type ExtensionsManifestsResponse as described in * https://docs.taler.net/design-documents/006-extensions.html#exchange * * @param extensions JSON object with the extension configuration @@ -181,14 +323,19 @@ TALER_extensions_is_enabled_type ( * and GNUNET_NO if the signature couldn't be verified. */ enum GNUNET_GenericReturnValue -TALER_extensions_verify_json_config_signature ( - json_t *extensions, +TALER_extensions_verify_manifests_signature ( + json_t *manifests, struct TALER_MasterSignatureP *extensions_sig, struct TALER_MasterPublicKeyP *master_pub); /* * TALER Age Restriction Extension + * + * This extension is special insofar as it directly interacts with coins and + * denominations. + * + * At the same time, it doesn't implement and http- or deposit-handlers. */ #define TALER_EXTENSION_SECTION_AGE_RESTRICTION (TALER_EXTENSION_SECTION_PREFIX \ @@ -204,102 +351,101 @@ TALER_extensions_verify_json_config_signature ( | 1 << 21) #define TALER_EXTENSION_AGE_RESTRICTION_DEFAULT_AGE_GROUPS "8:10:12:14:16:18:21" -/** - * @brief Registers the extension for age restriction to the list extensions - */ -enum GNUNET_GenericReturnValue -TALER_extension_age_restriction_register (); -/** - * @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. +/* + * @brief Configuration for Age Restriction */ -enum GNUNET_GenericReturnValue -TALER_parse_age_group_string ( - const char *groups, - struct TALER_AgeMask *mask); +struct TALER_AgeRestrictionConfig +{ + struct TALER_AgeMask mask; + uint8_t num_groups; +}; -/** - * @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 true when age restriction is configured and enabled. + * @brief Retrieve the age restriction configuration + * + * @return age restriction configuration if present, otherwise NULL. */ -bool -TALER_extensions_age_restriction_is_enabled (); +const struct TALER_AgeRestrictionConfig * +TALER_extensions_get_age_restriction_config (); /** - * @brief Returns true when age restriction is configured (might not be - * _enabled_, though). + * @brief Check if age restriction is enabled + * + * @return true, if age restriction is loaded, configured and enabled; otherwise false. */ bool -TALER_extensions_age_restriction_is_configured (); +TALER_extensions_is_age_restriction_enabled (); /** - * @brief 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. + * @brief Return the age mask for age restriction + * + * @return configured age mask, if age restriction is loaded, configured and enabled; otherwise zero mask. */ struct TALER_AgeMask -TALER_extensions_age_restriction_ageMask (); +TALER_extensions_get_age_restriction_mask (); -/** - * @brief Returns the amount of age groups defined. 0 means no age restriction - * enabled. +/* + * =================================== + * Policy extensions related functions + * =================================== */ -size_t -TALER_extensions_age_restriction_num_groups (); -/** - * @brief Parses a JSON object { "age_groups": "a:b:...y:z" }. +/* + * @brief Finds the extension for a given policy * - * @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. + * @param[in] policy_details JSON of the policy detail from a deposit request + * @param[out] extension On GNUNET_OK, the exentions handling the given policy + * @param[out] error_hint On GNUNET_SYSERR, will contain a hint for the reason why it failed + * @return GNUNET_OK on success, with *extension set to the correct extension. + * GNUNET_NO, when no extension was found. GNUNET_SYSERR when the JSON was + * invalid, with *error_hint maybe non-NULL. */ enum GNUNET_GenericReturnValue -TALER_JSON_parse_age_groups (const json_t *root, - struct TALER_AgeMask *mask); +TALER_extensions_from_policy_details ( + const json_t *policy_details, + const struct TALER_Extension **extension, + char **error_hint); +/* + * ================================ + * Merchant refund policy + * ================================ + */ +struct TALER_ExtensionPolicyMerchantRefundPolicyConfig +{ + struct GNUNET_TIME_Relative max_timeout; +}; /* - * TODO: Add Peer2Peer Extension + * ================================ + * Brandt-Vickrey Auctions policy + * ================================ + */ +/* + * @brief Configuration for Brandt-Vickrey auctions policy */ +struct TALER_ExtensionPolicyBrandtVickreyAuctionConfig +{ + uint16_t max_bidders; + uint16_t max_prices; + struct TALER_Amount auction_fee; +}; + + +/* + * ================================ + * Escrowed Payments policy + * ================================ + */ +/* + * @brief Configuration for escrowed payments policy + */ +struct TALER_ExtensionPolicyEscrowedPaymentsConfig +{ + struct GNUNET_TIME_Relative max_timeout; +}; #endif |