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/*
This file is part of GNUnet
Copyright (C) 2010-2015 GNUnet e.V.
GNUnet 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.
GNUnet 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 GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
/**
* @file identity-provider/jwt.c
* @brief helper library for JSON-Web-Tokens
* @author Martin Schanzenbach
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_signatures.h"
#include "gnunet_identity_attribute_lib.h"
#include <jansson.h>
#define JWT_ALG "alg"
/*TODO is this the correct way to define new algs? */
#define JWT_ALG_VALUE "ED512"
#define JWT_TYP "typ"
#define JWT_TYP_VALUE "jwt"
static char*
create_jwt_header(void)
{
json_t *root;
char *json_str;
root = json_object ();
json_object_set_new (root, JWT_ALG, json_string (JWT_ALG_VALUE));
json_object_set_new (root, JWT_TYP, json_string (JWT_TYP_VALUE));
json_str = json_dumps (root, JSON_INDENT(1));
json_decref (root);
return json_str;
}
/**
* Create a JWT from attributes
*
* @param sub_key the public of the subject
* @param attrs the attribute list
* @param priv_key the key used to sign the JWT
* @return a new base64-encoded JWT string.
*/
char*
jwt_create_from_list (const struct GNUNET_CRYPTO_EcdsaPublicKey *sub_key,
const struct GNUNET_IDENTITY_ATTRIBUTE_ClaimList *attrs,
const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv_key)
{
struct GNUNET_IDENTITY_ATTRIBUTE_ClaimListEntry *le;
struct GNUNET_CRYPTO_EcdsaPublicKey iss_key;
struct GNUNET_CRYPTO_EcdsaSignature signature;
struct GNUNET_CRYPTO_EccSignaturePurpose *purpose;
char* audience;
char* issuer;
char* header;
char* padding;
char* body_str;
char* result;
char* header_base64;
char* body_base64;
char* signature_target;
char* signature_base64;
char* attr_val_str;
json_t* body;
GNUNET_CRYPTO_ecdsa_key_get_public (priv_key, &iss_key);
/* TODO maybe we should use a local identity here */
issuer = GNUNET_STRINGS_data_to_string_alloc (&iss_key,
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey));
audience = GNUNET_STRINGS_data_to_string_alloc (sub_key,
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey));
header = create_jwt_header ();
body = json_object ();
/* TODO who is the issuer? local IdP or subject ? See self-issued tokens? */
json_object_set_new (body,
"iss", json_string (issuer));
json_object_set_new (body,
"sub", json_string (issuer));
/* TODO what should be in here exactly? */
json_object_set_new (body,
"aud", json_string (audience));
for (le = attrs->list_head; NULL != le; le = le->next)
{
/**
* TODO here we should have a function that
* calls the Attribute plugins to create a
* json representation for its value
*/
attr_val_str = GNUNET_IDENTITY_ATTRIBUTE_value_to_string (le->claim->type,
le->claim->data,
le->claim->data_size);
json_object_set_new (body,
le->claim->name,
json_string (attr_val_str));
GNUNET_free (attr_val_str);
}
body_str = json_dumps (body, JSON_INDENT(0));
json_decref (body);
GNUNET_STRINGS_base64_encode (header,
strlen (header),
&header_base64);
//Remove GNUNET padding of base64
padding = strtok(header_base64, "=");
while (NULL != padding)
padding = strtok(NULL, "=");
GNUNET_STRINGS_base64_encode (body_str,
strlen (body_str),
&body_base64);
//Remove GNUNET padding of base64
padding = strtok(body_base64, "=");
while (NULL != padding)
padding = strtok(NULL, "=");
GNUNET_free (issuer);
GNUNET_free (audience);
/**
* TODO
* Creating the JWT signature. This might not be
* standards compliant, check.
*/
GNUNET_asprintf (&signature_target, "%s,%s", header_base64, body_base64);
purpose =
GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
strlen (signature_target));
purpose->size =
htonl (strlen (signature_target) + sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose));
purpose->purpose = htonl(GNUNET_SIGNATURE_PURPOSE_GNUID_TOKEN);
GNUNET_memcpy (&purpose[1], signature_target, strlen (signature_target));
if (GNUNET_OK != GNUNET_CRYPTO_ecdsa_sign (priv_key,
purpose,
(struct GNUNET_CRYPTO_EcdsaSignature *)&signature))
{
GNUNET_free (signature_target);
GNUNET_free (body_str);
GNUNET_free (body_base64);
GNUNET_free (header_base64);
GNUNET_free (purpose);
return NULL;
}
GNUNET_STRINGS_base64_encode ((const char*)&signature,
sizeof (struct GNUNET_CRYPTO_EcdsaSignature),
&signature_base64);
GNUNET_asprintf (&result, "%s.%s.%s",
header_base64, body_base64, signature_base64);
GNUNET_free (signature_target);
GNUNET_free (header);
GNUNET_free (body_str);
GNUNET_free (signature_base64);
GNUNET_free (body_base64);
GNUNET_free (header_base64);
GNUNET_free (purpose);
return result;
}
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