exchange/src/mint-lib/mint_api_json.h

309 lines
7.0 KiB
C

/*
This file is part of TALER
Copyright (C) 2014, 2015 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file mint-lib/mint_api_json.h
* @brief functions to parse incoming requests (JSON snippets)
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include "taler_util.h"
#include <jansson.h>
/**
* Enumeration with the various commands for the
* #MAJ_parse_json interpreter.
*/
enum MAJ_Command
{
/**
* End of command list.
*/
MAJ_CMD_END,
/**
* Parse amount at current position.
*/
MAJ_CMD_AMOUNT,
/**
* Parse absolute time at current position.
*/
MAJ_CMD_TIME_ABSOLUTE,
/**
* Parse fixed binary value at current position.
*/
MAJ_CMD_BINARY_FIXED,
/**
* Parse variable-size binary value at current position.
*/
MAJ_CMD_BINARY_VARIABLE,
/**
* Parse RSA public key at current position.
*/
MAJ_CMD_RSA_PUBLIC_KEY,
/**
* Parse RSA signature at current position.
*/
MAJ_CMD_RSA_SIGNATURE,
/**
* Parse object with EdDSA signature and purpose at current position.
*/
MAJ_CMD_EDDSA_SIGNATURE,
/**
* Parse `const char *` JSON string at current position.
*/
MAJ_CMD_STRING,
/**
* Parse at current position.
*/
MAJ_CMD_C
};
/**
* Entry in parser specification for #MAJ_parse_json.
*/
struct MAJ_Specification
{
/**
* Command to execute.
*/
enum MAJ_Command cmd;
/**
* Name of the field to access.
*/
const char *field;
/**
* Further details for the command.
*/
union {
/**
* Where to store amount for #MAJ_CMD_AMOUNT.
*/
struct TALER_Amount *amount;
/**
* Where to store time, for #MAJ_CMD_TIME_ABSOLUTE.
*/
struct GNUNET_TIME_Absolute *abs_time;
/**
* Where to write binary data, for #MAJ_CMD_BINARY_FIXED.
*/
struct {
/**
* Where to write the data.
*/
void *dest;
/**
* How many bytes to write to @e dest.
*/
size_t dest_size;
} fixed_data;
/**
* Where to write binary data, for #MAJ_CMD_BINARY_VARIABLE.
*/
struct {
/**
* Where to store the pointer with the data (is allocated).
*/
void **dest_p;
/**
* Where to store the number of bytes allocated at `*dest`.
*/
size_t *dest_size_p;
} variable_data;
/**
* Where to store the RSA public key for #MAJ_CMD_RSA_PUBLIC_KEY
*/
struct GNUNET_CRYPTO_rsa_PublicKey **rsa_public_key;
/**
* Where to store the RSA signature for #MAJ_CMD_RSA_SIGNATURE
*/
struct GNUNET_CRYPTO_rsa_Signature **rsa_signature;
/**
* Details for #MAJ_CMD_EDDSA_SIGNATURE
*/
struct {
/**
* Where to store the purpose.
*/
struct GNUNET_CRYPTO_EccSignaturePurpose **purpose_p;
/**
* Key to verify the signature against.
*/
const struct GNUNET_CRYPTO_EddsaPublicKey *pub_key;
} eddsa_signature;
/**
* Where to store a pointer to the string.
*/
const char **strptr;
} details;
};
/**
* Navigate and parse data in a JSON tree.
*
* @param root the JSON node to start the navigation at.
* @param spec parse specification array
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
MAJ_parse_json (const json_t *root,
struct MAJ_Specification *spec);
/**
* Free all elements allocated during a
* #MAJ_parse_json() operation.
*
* @param spec specification of the parse operation
*/
void
MAJ_parse_free (struct MAJ_Specification *spec);
/**
* End of a parser specification.
*/
#define MAJ_spec_end { .cmd = MAJ_CMD_END }
/**
* Fixed size object (in network byte order, encoded using Crockford
* Base32hex encoding).
*
* @param name name of the JSON field
* @param obj pointer where to write the data (type of `*obj` will determine size)
*/
#define MAJ_spec_fixed_auto(name,obj) { .cmd = MAJ_CMD_BINARY_FIXED, .field = name, .details.fixed_data.dest = obj, .details.fixed_data.dest_size = sizeof (*obj) }
/**
* Variable size object (in network byte order, encoded using Crockford
* Base32hex encoding).
*
* @param name name of the JSON field
* @param obj_ptr pointer where to write the data (a `void **`)
* @param size where to store the number of bytes allocated for @a obj (of type `size_t *`
*/
#define MAJ_spec_varsize(name,obj,size) { .cmd = MAJ_CMD_BINARY_VARIABLE, .field = name, .details.variable_data.dest_p = obj, .details.variable_data.dest_size_p = size }
/**
* The expected field stores a string.
*
* @param name name of the JSON field
* @param strptr where to store a pointer to the field
*/
struct MAJ_Specification
MAJ_spec_string (const char *name,
const char **strptr);
/**
* Absolute time.
*
* @param name name of the JSON field
* @param at where to store the absolute time found under @a name
*/
struct MAJ_Specification
MAJ_spec_absolute_time (const char *name,
struct GNUNET_TIME_Absolute *at);
/**
* Specification for parsing an amount value.
*
* @param name name of the JSON field
* @param at where to store the absolute time found under @a name
*/
struct MAJ_Specification
MAJ_spec_amount (const char *name,
struct TALER_Amount *amount);
/**
* Specification for parsing an EdDSA object signature with purpose.
* Also validates the signature (!).
*
* @param name name of the JSON field
* @param purpose_p where to store the purpose
* @param pub_key public key to use for validation
*/
struct MAJ_Specification
MAJ_spec_eddsa_signed_purpose (const char *name,
struct GNUNET_CRYPTO_EccSignaturePurpose **purpose_p,
const struct GNUNET_CRYPTO_EddsaPublicKey *pub_key);
/**
* Specification for parsing an RSA public key.
*
* @param name name of the JSON field
* @param pk where to store the RSA key found under @a name
*/
struct MAJ_Specification
MAJ_spec_rsa_public_key (const char *name,
struct GNUNET_CRYPTO_rsa_PublicKey **pk);
/**
* Specification for parsing an RSA signature.
*
* @param name name of the JSON field
* @param sig where to store the RSA signature found under @a name
*/
struct MAJ_Specification
MAJ_spec_rsa_signature (const char *name,
struct GNUNET_CRYPTO_rsa_Signature **sig);
/* end of mint_api_json.h */