/* This file is part of TALER Copyright (C) 2014, 2015, 2016, 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_json_lib.h * @brief helper functions for JSON processing using libjansson * @author Sree Harsha Totakura * @author Christian Grothoff */ #ifndef TALER_JSON_LIB_H_ #define TALER_JSON_LIB_H_ #include #include #include #include "taler_util.h" #include "taler_error_codes.h" /** * Print JSON parsing related error information * @deprecated */ #define TALER_json_warn(error) \ GNUNET_log (GNUNET_ERROR_TYPE_WARNING, \ "JSON parsing failed at %s:%u: %s (%s)\n", \ __FILE__, __LINE__, error.text, error.source) /** * Generate packer instruction for a JSON field of type * absolute time creating a human-readable timestamp. * * @param name name of the field to add to the object * @param at absolute time to pack * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_time_abs_human (const char *name, struct GNUNET_TIME_Absolute at); /** * Put an error code into a JSON reply, including * both the numeric value and the hint. * * @param ec error code to encode using canonical field names */ #define TALER_JSON_pack_ec(ec) \ GNUNET_JSON_pack_string ("hint", TALER_ErrorCode_get_hint (ec)), \ GNUNET_JSON_pack_uint64 ("code", ec) /** * Generate packer instruction for a JSON field of type * absolute time creating a human-readable timestamp. * * @param name name of the field to add to the object * @param at absolute time to pack * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_time_abs_nbo_human (const char *name, struct GNUNET_TIME_AbsoluteNBO at); /** * Generate packer instruction for a JSON field of type * denomination public key. * * @param name name of the field to add to the object * @param pk public key * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_denom_pub ( const char *name, const struct TALER_DenominationPublicKey *pk); /** * Generate packer instruction for a JSON field of type * denomination signature. * * @param name name of the field to add to the object * @param sig signature * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_denom_sig ( const char *name, const struct TALER_DenominationSignature *sig); /** * Generate packer instruction for a JSON field of type * blinded denomination signature (that needs to be * unblinded before it becomes valid). * * @param name name of the field to add to the object * @param sig signature * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_blinded_denom_sig ( const char *name, const struct TALER_BlindedDenominationSignature *sig); /** * Generate packer instruction for a JSON field of type * amount. * * @param name name of the field to add to the object * @param amount valid amount to pack * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_amount (const char *name, const struct TALER_Amount *amount); /** * Generate packer instruction for a JSON field of type * amount. * * @param name name of the field to add to the object * @param amount valid amount to pack * @return json pack specification */ struct GNUNET_JSON_PackSpec TALER_JSON_pack_amount_nbo (const char *name, const struct TALER_AmountNBO *amount); /** * Convert a TALER amount to a JSON object. * * @param amount the amount * @return a json object describing the amount */ json_t * TALER_JSON_from_amount (const struct TALER_Amount *amount); /** * Convert a TALER amount to a JSON object. * * @param amount the amount * @return a json object describing the amount */ json_t * TALER_JSON_from_amount_nbo (const struct TALER_AmountNBO *amount); /** * Provide specification to parse given JSON object to an amount. * The @a currency must be a valid pointer while the * parsing is done, a copy is not made. * * @param name name of the amount field in the JSON * @param currency the currency the amount must be in * @param[out] r_amount where the amount has to be written * @return spec for parsing an amount */ struct GNUNET_JSON_Specification TALER_JSON_spec_amount (const char *name, const char *currency, struct TALER_Amount *r_amount); /** * Provide specification to parse given JSON object to an amount * in network byte order. * The @a currency must be a valid pointer while the * parsing is done, a copy is not made. * * @param name name of the amount field in the JSON * @param currency the currency the amount must be in * @param[out] r_amount where the amount has to be written * @return spec for parsing an amount */ struct GNUNET_JSON_Specification TALER_JSON_spec_amount_nbo (const char *name, const char *currency, struct TALER_AmountNBO *r_amount); /** * Provide specification to parse given JSON object to an amount * in any currency. * * @param name name of the amount field in the JSON * @param[out] r_amount where the amount has to be written * @return spec for parsing an amount */ struct GNUNET_JSON_Specification TALER_JSON_spec_amount_any (const char *name, struct TALER_Amount *r_amount); /** * Provide specification to parse given JSON object to an amount * in any currency in network byte order. * * @param name name of the amount field in the JSON * @param[out] r_amount where the amount has to be written * @return spec for parsing an amount */ struct GNUNET_JSON_Specification TALER_JSON_spec_amount_any_nbo (const char *name, struct TALER_AmountNBO *r_amount); /** * Generate line in parser specification for denomination public key. * * @param field name of the field * @param[out] pk key to initialize * @return corresponding field spec */ struct GNUNET_JSON_Specification TALER_JSON_spec_denom_pub (const char *field, struct TALER_DenominationPublicKey *pk); /** * Generate line in parser specification for denomination signature. * * @param field name of the field * @param sig the signature to initialize * @return corresponding field spec */ struct GNUNET_JSON_Specification TALER_JSON_spec_denom_sig (const char *field, struct TALER_DenominationSignature *sig); /** * Generate line in parser specification for a * blinded denomination signature. * * @param field name of the field * @param sig the blinded signature to initialize * @return corresponding field spec */ struct GNUNET_JSON_Specification TALER_JSON_spec_blinded_denom_sig ( const char *field, struct TALER_BlindedDenominationSignature *sig); /** * The expected field stores a possibly internationalized string. * Internationalization means that there is another field "$name_i18n" * which is an object where the keys are languages. If this is * present, and if @a language_pattern is non-NULL, this function * should return the best match from @a language pattern from the * "_i18n" field. If no language matches, the normal field under * @a name is to be returned. * * The @a language_pattern is given using the format from * https://tools.ietf.org/html/rfc7231#section-5.3.1 * so that #TALER_language_matches() can be used. * * @param name name of the JSON field * @param language_pattern language pattern to use to find best match, possibly NULL * @param[out] strptr where to store a pointer to the field with the best variant */ struct GNUNET_JSON_Specification TALER_JSON_spec_i18n_string (const char *name, const char *language_pattern, const char **strptr); /** * The expected field stores a possibly internationalized string. * Internationalization means that there is another field "$name_i18n" which * is an object where the keys are languages. If this is present, this * function should return the best match based on the locale from the "_i18n" * field. If no language matches, the normal field under @a name is to be * returned. * * @param name name of the JSON field * @param[out] strptr where to store a pointer to the field with the best variant */ struct GNUNET_JSON_Specification TALER_JSON_spec_i18n_str (const char *name, const char **strptr); /** * Hash a JSON for binary signing. * * See https://tools.ietf.org/html/draft-rundgren-json-canonicalization-scheme-15 * for fun JSON canonicalization problems. Callers must ensure that * those are avoided in the input. We will use libjanson's "JSON_COMPACT" * encoding for whitespace and "JSON_SORT_KEYS" to canonicalize as best * as we can. * * @param[in] json some JSON value to hash * @param[out] hc resulting hash code * @return #GNUNET_OK on success, * #GNUNET_NO if @a json was malformed * #GNUNET_SYSERR on internal error */ enum GNUNET_GenericReturnValue TALER_JSON_contract_hash (const json_t *json, struct TALER_PrivateContractHash *hc); /** * Take a given contract with "forgettable" fields marked * but with 'True' instead of a real salt. Replaces all * 'True' values with proper random salts. Fails if any * forgettable markers are neither 'True' nor valid salts. * * @param[in,out] json JSON to transform * @return #GNUNET_OK on success */ enum GNUNET_GenericReturnValue TALER_JSON_contract_seed_forgettable (json_t *json); /** * Mark part of a contract object as 'forgettable'. * * @param[in,out] json some JSON object to modify * @param field name of the field to mark as forgettable * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ enum GNUNET_GenericReturnValue TALER_JSON_contract_mark_forgettable (json_t *json, const char *field); /** * Forget part of a contract object. * * @param[in,out] json some JSON object to modify * @param field name of the field to forget * @return #GNUNET_OK on success, * #GNUNET_NO if the field was already forgotten before * #GNUNET_SYSERR on error */ enum GNUNET_GenericReturnValue TALER_JSON_contract_part_forget (json_t *json, const char *field); /** * Called for each path found after expanding a path. * * @param cls the closure. * @param object_id the name of the object that is pointed to. * @param parent the parent of the object at @e object_id. */ typedef void (*TALER_JSON_ExpandPathCallback) ( void *cls, const char *object_id, json_t *parent); /** * Expands a path for a json object. May call the callback several times * if the path contains a wildcard. * * @param json the json object the path references. * @param path the path to expand. Must begin with "$." and follow dot notation, * and may include array indices and wildcards. * @param cb the callback. * @param cb_cls closure for the callback. * @return #GNUNET_OK on success, #GNUNET_SYSERR if @e path is invalid. */ enum GNUNET_GenericReturnValue TALER_JSON_expand_path (json_t *json, const char *path, TALER_JSON_ExpandPathCallback cb, void *cb_cls); /** * Extract the Taler error code from the given @a json object. * Note that #TALER_EC_NONE is returned if no "code" is present. * * @param json response to extract the error code from * @return the "code" value from @a json */ enum TALER_ErrorCode TALER_JSON_get_error_code (const json_t *json); /** * Extract the Taler error hint from the given @a json object. * Note that NULL is returned if no "hint" is present. * * @param json response to extract the error hint from * @return the "hint" value from @a json; only valid as long as @a json is valid */ const char * TALER_JSON_get_error_hint (const json_t *json); /** * Extract the Taler error code from the given @a data object, which is expected to be in JSON. * Note that #TALER_EC_INVALID is returned if no "code" is present or if @a data is not in JSON. * * @param data response to extract the error code from * @param data_size number of bytes in @a data * @return the "code" value from @a json */ enum TALER_ErrorCode TALER_JSON_get_error_code2 (const void *data, size_t data_size); /* **************** /wire account offline signing **************** */ /** * Compute the hash of the given wire details. The resulting * hash is what is put into the contract. Also performs rudimentary * checks on the account data *if* supported. * * @param wire_s wire details to hash * @param[out] hc set to the hash * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed */ enum GNUNET_GenericReturnValue TALER_JSON_merchant_wire_signature_hash (const json_t *wire_s, struct TALER_MerchantWireHash *hc); /** * Check the signature in @a wire_s. Also performs rudimentary * checks on the account data *if* supported. * * @param wire_s signed wire information of an exchange * @param master_pub master public key of the exchange * @return #GNUNET_OK if signature is valid */ enum GNUNET_GenericReturnValue TALER_JSON_exchange_wire_signature_check ( const json_t *wire_s, const struct TALER_MasterPublicKeyP *master_pub); /** * Create a signed wire statement for the given account. * * @param payto_uri account specification * @param master_priv private key to sign with * @return NULL if @a payto_uri is malformed */ json_t * TALER_JSON_exchange_wire_signature_make ( const char *payto_uri, const struct TALER_MasterPrivateKeyP *master_priv); /** * Extract a string from @a object under the field @a field, but respecting * the Taler i18n rules and the language preferences expressed in @a * language_pattern. * * Basically, the @a object may optionally contain a sub-object * "${field}_i18n" with a map from IETF BCP 47 language tags to a localized * version of the string. If this map exists and contains an entry that * matches the @a language pattern, that object (usually a string) is * returned. If the @a language_pattern does not match any entry, or if the * i18n sub-object does not exist, we simply return @a field of @a object * (also usually a string). * * If @a object does not have a member @a field we return NULL (error). * * @param object the object to extract internationalized * content from * @param language_pattern a language preferences string * like "fr-CH, fr;q=0.9, en;q=0.8, *;q=0.1", following * https://tools.ietf.org/html/rfc7231#section-5.3.1 * @param field name of the field to extract * @return NULL on error, otherwise the member from * @a object. Note that the reference counter is * NOT incremented. */ const json_t * TALER_JSON_extract_i18n (const json_t *object, const char *language_pattern, const char *field); /** * Check whether a given @a i18n object is wellformed. * * @param i18n object with internationalized content * @return true if @a i18n is well-formed */ bool TALER_JSON_check_i18n (const json_t *i18n); /** * Obtain the wire method associated with the given * wire account details. @a wire_s must contain a payto://-URL * under 'url'. * * @return NULL on error */ char * TALER_JSON_wire_to_method (const json_t *wire_s); /** * Obtain the payto://-URL associated with the given * wire account details. @a wire_s must contain a payto://-URL * under 'payto_uri'. * * @return NULL on error */ char * TALER_JSON_wire_to_payto (const json_t *wire_s); /** * Hash @a extensions in deposits. * * @param extensions contract extensions to hash * @param[out] ech where to write the extension hash */ void TALER_deposit_extension_hash (const json_t *extensions, struct TALER_ExtensionContractHash *ech); /** * Hash the @a config of an extension, given as JSON * * @param config configuration of the extension * @param[out] eh where to write the extension hash * @return GNUNET_OK on success, GNUNET_SYSERR on failure */ enum GNUNET_GenericReturnValue TALER_JSON_extensions_config_hash (const json_t *config, struct TALER_ExtensionConfigHash *eh); /** * Parses a JSON object { "extension": "age_restriction", "mask": }. * * @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_agemask (const json_t *root, struct TALER_AgeMask *mask); #endif /* TALER_JSON_LIB_H_ */ /* End of taler_json_lib.h */