/*
This file is part of TALER
Copyright (C) 2014-2024 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"
/**
* Version of this API, for compatibility tests.
*/
#define TALER_JSON_LIB_VERSION 0x00020000
/**
* Details about an encrypted contract.
*/
struct TALER_EncryptedContract
{
/**
* Signature of the client affiming this encrypted contract.
*/
struct TALER_PurseContractSignatureP econtract_sig;
/**
* Contract decryption key for the purse.
*/
struct TALER_ContractDiffiePublicP contract_pub;
/**
* Encrypted contract, can be NULL.
*/
void *econtract;
/**
* Number of bytes in @e econtract.
*/
size_t econtract_size;
};
/**
* 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
* 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
* blinded planchet.
*
* @param name name of the field to add to the object
* @param blinded_planchet blinded planchet
* @return json pack specification
*/
struct GNUNET_JSON_PackSpec
TALER_JSON_pack_blinded_planchet (
const char *name,
const struct TALER_BlindedPlanchet *blinded_planchet);
/**
* Generate packer instruction for a JSON field of type
* exchange withdraw values (/csr).
*
* @param name name of the field to add to the object
* @param ewv values to transmit
* @return json pack specification
*/
struct GNUNET_JSON_PackSpec
TALER_JSON_pack_exchange_withdraw_values (
const char *name,
const struct TALER_ExchangeWithdrawValues *ewv);
/**
* 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
* encrypted contract.
*
* @param name name of the field to add to the object
* @param econtract the encrypted contract
* @return json pack specification
*/
struct GNUNET_JSON_PackSpec
TALER_JSON_pack_econtract (
const char *name,
const struct TALER_EncryptedContract *econtract);
/**
* Generate packer instruction for a JSON field of type age_commitment
*
* @param name name of the field to add to the object
* @param age_commitment age commitment to add
* @return json pack specification
*/
struct GNUNET_JSON_PackSpec
TALER_JSON_pack_age_commitment (
const char *name,
const struct TALER_AgeCommitment *age_commitment);
/**
* 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);
/**
* 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
* a currency specification.
*
* @param name name of the amount field in the JSON
* @param currency_code currency code to parse
* @param[out] r_cspec where the currency spec has to be written
* @return spec for parsing an amount
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_currency_specification (
const char *name,
const char *currency_code,
struct TALER_CurrencySpecification *r_cspec);
/**
* 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 encrypted contract.
*
* @param name name of the amount field in the JSON
* @param[out] econtract where to store the encrypted contract
* @return spec for parsing an amount
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_econtract (const char *name,
struct TALER_EncryptedContract *econtract);
/**
* Provide specification to parse a given JSON object to an age commitment.
*
* @param name name of the age commitment field in the JSON
* @param[out] age_commitment where to store the age commitment
* @return spec for parsing an age commitment
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_age_commitment (const char *name,
struct TALER_AgeCommitment *age_commitment);
/**
* Provide specification to parse an OTP key.
* An OTP key must be an RFC 3548 base32-encoded
* value (so NOT our usual Crockford-base32 encoding!).
*
* @param name name of the OTP key field in the JSON
* @param[out] otp_key where to store the OTP key
* @return spec for parsing an age commitment
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_otp_key (const char *name,
const char **otp_key);
/**
* Provide specification to parse an OTP method type.
* The value could be provided as an integer or
* as a descriptive string.
*
* @param name name of the OTP method type in the JSON
* @param[out] mca where to store the method type
* @return spec for parsing an age commitment
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_otp_type (const char *name,
enum TALER_MerchantConfirmationAlgorithm *mca);
/**
* Generate specification to parse all fees for
* a denomination under a prefix @a pfx.
*
* @param pfx string prefix to use
* @param currency which currency to expect
* @param[out] dfs a `struct TALER_DenomFeeSet` to initialize
*/
#define TALER_JSON_SPEC_DENOM_FEES(pfx,currency,dfs) \
TALER_JSON_spec_amount (pfx "_withdraw", (currency), &(dfs)->withdraw), \
TALER_JSON_spec_amount (pfx "_deposit", (currency), &(dfs)->deposit), \
TALER_JSON_spec_amount (pfx "_refresh", (currency), &(dfs)->refresh), \
TALER_JSON_spec_amount (pfx "_refund", (currency), &(dfs)->refund)
/**
* Macro to pack all of a denominations' fees under
* a given @a pfx.
*
* @param pfx string prefix to use
* @param dfs a `struct TALER_DenomFeeSet` to pack
*/
#define TALER_JSON_PACK_DENOM_FEES(pfx, dfs) \
TALER_JSON_pack_amount (pfx "_withdraw", &(dfs)->withdraw), \
TALER_JSON_pack_amount (pfx "_deposit", &(dfs)->deposit), \
TALER_JSON_pack_amount (pfx "_refresh", &(dfs)->refresh), \
TALER_JSON_pack_amount (pfx "_refund", &(dfs)->refund)
/**
* Generate specification to parse all global fees.
*
* @param currency which currency to expect
* @param[out] gfs a `struct TALER_GlobalFeeSet` to initialize
*/
#define TALER_JSON_SPEC_GLOBAL_FEES(currency,gfs) \
TALER_JSON_spec_amount ("history_fee", (currency), &(gfs)->history), \
TALER_JSON_spec_amount ("account_fee", (currency), &(gfs)->account), \
TALER_JSON_spec_amount ("purse_fee", (currency), &(gfs)->purse)
/**
* Macro to pack all of the global fees.
*
* @param gfs a `struct TALER_GlobalFeeSet` to pack
*/
#define TALER_JSON_PACK_GLOBAL_FEES(gfs) \
TALER_JSON_pack_amount ("history_fee", &(gfs)->history), \
TALER_JSON_pack_amount ("account_fee", &(gfs)->account), \
TALER_JSON_pack_amount ("purse_fee", &(gfs)->purse)
/**
* Generate a parser for a group of denominations.
*
* @param[in] field name of the field, maybe NULL
* @param[in] currency name of the currency
* @param[out] group denomination group information
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_denomination_group (const char *field,
const char *currency,
struct TALER_DenominationGroup *group);
/**
* 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 error codes.
*
* @param field name of the field
* @param[out] ec error code to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_ec (const char *field,
enum TALER_ErrorCode *ec);
/**
* Generate line in parser specification for
* HTTP/HTTPS URLs.
*
* @param field name of the field
* @param[out] url web URL to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_web_url (const char *field,
const char **url);
/**
* Generate line in parser specification for
* "payto://" URIs.
*
* @param field name of the field
* @param[out] payto_uri RFC 8905 URI to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_payto_uri (const char *field,
const char **payto_uri);
/**
* Generate line in parser specification for AML decision states.
*
* @param field name of the field
* @param[out] aml_state AML state to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_aml_decision (const char *field,
enum TALER_AmlDecisionState *aml_state);
/**
* Representation of a protocol version.
*/
struct TALER_JSON_ProtocolVersion
{
/**
* Current version of the protocol.
*/
unsigned int current;
/**
* Implementation revision for the @e current
* version.
*/
unsigned int revision;
/**
* Number of protocol versions this @e revision is
* backwards-compatible with. Subtract this number
* from @e current to get the minimum protocol version
* required from the client.
*/
unsigned int age;
};
/**
* Generate line in parser specification for protocol
* versions (``/config``). The field must be a string
* encoding the version as "$CURRENT:$REVISION:$AGE".
*
* @param field name of the field (usually "version")
* @param[out] ver protocol versions to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_version (const char *field,
struct TALER_JSON_ProtocolVersion *ver);
/**
* Generate a parser specification for a denomination public key of a given
* cipher.
*
* @param field name of the field
* @param cipher which cipher type to parse for
* @param[out] pk key to fill
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_denom_pub_cipher (
const char *field,
enum GNUNET_CRYPTO_BlindSignatureAlgorithm cipher,
struct TALER_DenominationPublicKey *pk);
/**
* Generate line in parser specification for denomination signature.
*
* @param field name of the field
* @param[out] 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[out] 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);
/**
* Generate line in parser specification for
* exchange withdraw values (/csr).
*
* @param field name of the field
* @param[out] ewv the exchange withdraw values to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_exchange_withdraw_values (
const char *field,
struct TALER_ExchangeWithdrawValues *ewv);
/**
* Generate line in parser specification for a
* blinded planchet.
*
* @param field name of the field
* @param[out] blinded_planchet the blinded planchet to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_blinded_planchet (const char *field,
struct TALER_BlindedPlanchet *blinded_planchet);
/**
* 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);
/**
* Generate line in parser specification for a
* token issue signature.
*
* @param field name of the field
* @param[out] sig the signature to initialize
* @return corresponding field spec
*/
struct GNUNET_JSON_Specification
TALER_JSON_spec_token_issue_sig (const char *field,
struct TALER_TokenIssueSignature *sig);
/**
* 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_PrivateContractHashP *hc);
/**
* Take a given @a contract with "forgettable" fields marked in the @a spec
* with 'True' instead of a real salt. Replaces all 'True' values with proper
* random salts in the actual @a contract. Fails if any forgettable markers
* are neither 'True' nor valid salts.
*
* @param spec specification with forgettable fields
* @param[in,out] contract JSON contract to transform
* @return #GNUNET_OK on success
*/
enum GNUNET_GenericReturnValue
TALER_JSON_contract_seed_forgettable (const json_t *spec,
json_t *contract);
/**
* 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_MerchantWireHashP *hc);
/**
* 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 policy extensions in deposits.
*
* @param policy contract policy extension to hash
* @param[out] ech where to write the policy hash
*/
void
TALER_deposit_policy_hash (const json_t *policy,
struct TALER_ExtensionPolicyHashP *ech);
/**
* Hash the @a manifests of extensions, given as JSON
*
* @param manifests Manifests of the extensions
* @param[out] eh where to write the hash
* @return GNUNET_OK on success, GNUNET_SYSERR on failure
*/
enum GNUNET_GenericReturnValue
TALER_JSON_extensions_manifests_hash (const json_t *manifests,
struct TALER_ExtensionManifestsHashP *eh);
/**
* Canonicalize a JSON input to a string according to RFC 8785.
*/
char *
TALER_JSON_canonicalize (const json_t *input);
#endif /* TALER_JSON_LIB_H_ */
/* End of taler_json_lib.h */