exchange/src/mint-lib/mint_api_json.c

484 lines
12 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.c
* @brief functions to parse incoming requests (JSON snippets)
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include "mint_api_json.h"
/**
* Navigate and parse data in a JSON tree.
*
* @param root the JSON node to start the navigation at.
* @param spec parse specification array
* @return offset in @a spec where parsing failed, -1 on success (!)
*/
static int
parse_json (json_t *root,
struct MAJ_Specification *spec)
{
int i;
json_t *pos; /* what's our current position? */
pos = root;
for (i=0;MAJ_CMD_END != spec[i].cmd;i++)
{
pos = json_object_get (root,
spec[i].field);
if (NULL == pos)
{
GNUNET_break_op (0);
return i;
}
switch (spec[i].cmd)
{
case MAJ_CMD_END:
GNUNET_assert (0);
return i;
case MAJ_CMD_AMOUNT:
if (GNUNET_OK !=
TALER_json_to_amount (pos,
spec[i].details.amount))
{
GNUNET_break_op (0);
return i;
}
break;
case MAJ_CMD_TIME_ABSOLUTE:
if (GNUNET_OK !=
TALER_json_to_abs (pos,
spec[i].details.abs_time))
{
GNUNET_break_op (0);
return i;
}
break;
case MAJ_CMD_STRING:
{
const char *str;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
*spec[i].details.strptr = str;
}
break;
case MAJ_CMD_BINARY_FIXED:
{
const char *str;
int res;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
res = GNUNET_STRINGS_string_to_data (str, strlen (str),
spec[i].details.fixed_data.dest,
spec[i].details.fixed_data.dest_size);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
return i;
}
}
break;
case MAJ_CMD_BINARY_VARIABLE:
{
const char *str;
size_t size;
void *data;
int res;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
size = (strlen (str) * 5) / 8;
if (size >= 1024)
{
GNUNET_break_op (0);
return i;
}
data = GNUNET_malloc (size);
res = GNUNET_STRINGS_string_to_data (str,
strlen (str),
data,
size);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
GNUNET_free (data);
return i;
}
*spec[i].details.variable_data.dest_p = data;
*spec[i].details.variable_data.dest_size_p = size;
}
break;
case MAJ_CMD_RSA_PUBLIC_KEY:
{
size_t size;
const char *str;
int res;
void *buf;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
size = (strlen (str) * 5) / 8;
buf = GNUNET_malloc (size);
res = GNUNET_STRINGS_string_to_data (str,
strlen (str),
buf,
size);
if (GNUNET_OK != res)
{
GNUNET_free (buf);
GNUNET_break_op (0);
return i;
}
*spec[i].details.rsa_public_key
= GNUNET_CRYPTO_rsa_public_key_decode (buf,
size);
GNUNET_free (buf);
if (NULL == spec[i].details.rsa_public_key)
{
GNUNET_break_op (0);
return i;
}
}
break;
case MAJ_CMD_RSA_SIGNATURE:
{
size_t size;
const char *str;
int res;
void *buf;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
size = (strlen (str) * 5) / 8;
buf = GNUNET_malloc (size);
res = GNUNET_STRINGS_string_to_data (str,
strlen (str),
buf,
size);
if (GNUNET_OK != res)
{
GNUNET_free (buf);
GNUNET_break_op (0);
return i;
}
*spec[i].details.rsa_signature
= GNUNET_CRYPTO_rsa_signature_decode (buf,
size);
GNUNET_free (buf);
if (NULL == spec[i].details.rsa_signature)
return i;
}
break;
case MAJ_CMD_EDDSA_SIGNATURE:
{
struct TALER_CoinSpendSignatureP sig;
struct GNUNET_CRYPTO_EccSignaturePurpose *purpose;
size_t size;
struct MAJ_Specification sig_spec[] = {
MAJ_spec_fixed_auto ("eddsa_sig", &sig),
MAJ_spec_varsize ("eddsa_val", (void**) &purpose, &size),
MAJ_spec_end
};
if (GNUNET_OK !=
MAJ_parse_json (pos,
sig_spec))
{
GNUNET_break_op (0);
MAJ_parse_free (sig_spec);
return i;
}
if (size != ntohl (purpose->size))
{
GNUNET_break_op (0);
MAJ_parse_free (sig_spec);
return i;
}
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (ntohl (purpose->purpose),
purpose,
&sig.eddsa_signature,
spec[i].details.eddsa_signature.pub_key))
{
GNUNET_break_op (0);
MAJ_parse_free (sig_spec);
return i;
}
*spec[i].details.eddsa_signature.purpose_p = purpose;
}
break;
default:
GNUNET_break (0);
return i;
}
}
return -1; /* all OK! */
}
/**
* Free all elements allocated during a
* #MAJ_parse_json() operation.
*
* @param spec specification of the parse operation
* @param end number of elements in @a spec to process
*/
static void
parse_free (struct MAJ_Specification *spec,
int end)
{
int i;
for (i=0;i<end;i++)
{
switch (spec[i].cmd)
{
case MAJ_CMD_END:
GNUNET_assert (0);
return;
case MAJ_CMD_AMOUNT:
break;
case MAJ_CMD_TIME_ABSOLUTE:
break;
case MAJ_CMD_BINARY_FIXED:
break;
case MAJ_CMD_STRING:
break;
case MAJ_CMD_BINARY_VARIABLE:
GNUNET_free (*spec[i].details.variable_data.dest_p);
*spec[i].details.variable_data.dest_p = NULL;
*spec[i].details.variable_data.dest_size_p = 0;
break;
case MAJ_CMD_RSA_PUBLIC_KEY:
GNUNET_CRYPTO_rsa_public_key_free (*spec[i].details.rsa_public_key);
*spec[i].details.rsa_public_key = NULL;
break;
case MAJ_CMD_RSA_SIGNATURE:
GNUNET_CRYPTO_rsa_signature_free (*spec[i].details.rsa_signature);
*spec[i].details.rsa_signature = NULL;
break;
case MAJ_CMD_EDDSA_SIGNATURE:
GNUNET_free (*spec[i].details.eddsa_signature.purpose_p);
*spec[i].details.eddsa_signature.purpose_p = NULL;
default:
GNUNET_break (0);
break;
}
}
}
/**
* 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)
{
int ret;
ret = parse_json ((json_t *) root,
spec);
if (-1 == ret)
return GNUNET_OK;
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"JSON field `%s` (%d) had unexpected value\n",
spec[ret].field,
ret);
parse_free (spec, ret);
return GNUNET_SYSERR;
}
/**
* 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)
{
int i;
for (i=0;MAJ_CMD_END != spec[i].cmd;i++) ;
parse_free (spec, i);
}
/**
* 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)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_STRING,
.field = name,
.details.strptr = strptr
};
return ret;
}
/**
* Specification for parsing an absolute time 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_absolute_time (const char *name,
struct GNUNET_TIME_Absolute *at)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_TIME_ABSOLUTE,
.field = name,
.details.abs_time = at
};
return ret;
}
/**
* 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)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_AMOUNT,
.field = name,
.details.amount = amount
};
return ret;
}
/**
* 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)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_RSA_PUBLIC_KEY,
.field = name,
.details.rsa_public_key = pk
};
return ret;
}
/**
* 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)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_RSA_SIGNATURE,
.field = name,
.details.rsa_signature = sig
};
return ret;
}
/**
* 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)
{
struct MAJ_Specification ret =
{
.cmd = MAJ_CMD_EDDSA_SIGNATURE,
.field = name,
.details.eddsa_signature.purpose_p = purpose_p,
.details.eddsa_signature.pub_key = pub_key
};
return ret;
}
/* end of mint_api_json.c */