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/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GNUTLS.
*
* The GNUTLS library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA
*
*/
#include "gnutls_int.h"
#include "gnutls_errors.h"
#include "gnutls_auth.h"
#include "gnutls_auth_int.h"
#include "gnutls_algorithms.h"
#include "auth_cert.h"
#include <gnutls_datum.h>
/* The functions here are used in order for authentication algorithms
* to be able to retrieve the needed credentials eg public and private
* key etc.
*/
/**
* MHD__gnutls_credentials_clear - Clears all the credentials previously set
* @session: is a #MHD_gtls_session_t structure.
*
* Clears all the credentials previously set in this session.
*
**/
void
MHD__gnutls_credentials_clear (MHD_gtls_session_t session)
{
if (session->key && session->key->cred)
{ /* beginning of the list */
auth_cred_st *ccred, *ncred;
ccred = session->key->cred;
while (ccred != NULL)
{
ncred = ccred->next;
MHD_gnutls_free (ccred);
ccred = ncred;
}
session->key->cred = NULL;
}
}
/*
* This creates a linked list of the form:
* { algorithm, credentials, pointer to next }
*/
/**
* MHD__gnutls_credentials_set - Sets the needed credentials for the specified authentication algorithm.
* @session: is a #MHD_gtls_session_t structure.
* @type: is the type of the credentials
* @cred: is a pointer to a structure.
*
* Sets the needed credentials for the specified type.
* Eg username, password - or public and private keys etc.
* The (void* cred) parameter is a structure that depends on the
* specified type and on the current session (client or server).
* [ In order to minimize memory usage, and share credentials between
* several threads gnutls keeps a pointer to cred, and not the whole cred
* structure. Thus you will have to keep the structure allocated until
* you call MHD__gnutls_deinit(). ]
*
* For GNUTLS_CRD_SRP cred should be MHD_gnutls_srp_client_credentials_t
* in case of a client, and MHD_gnutls_srp_server_credentials_t, in case
* of a server.
*
* For GNUTLS_CRD_CERTIFICATE cred should be MHD_gtls_cert_credentials_t.
*
**/
int
MHD__gnutls_credentials_set (MHD_gtls_session_t session,
enum MHD_GNUTLS_CredentialsType type, void *cred)
{
auth_cred_st *ccred = NULL, *pcred = NULL;
int exists = 0;
if (session->key->cred == NULL)
{ /* beginning of the list */
session->key->cred = MHD_gnutls_malloc (sizeof (auth_cred_st));
if (session->key->cred == NULL)
return GNUTLS_E_MEMORY_ERROR;
/* copy credentials locally */
session->key->cred->credentials = cred;
session->key->cred->next = NULL;
session->key->cred->algorithm = type;
}
else
{
ccred = session->key->cred;
while (ccred != NULL)
{
if (ccred->algorithm == type)
{
exists = 1;
break;
}
pcred = ccred;
ccred = ccred->next;
}
/* After this, pcred is not null.
*/
if (exists == 0)
{ /* new entry */
pcred->next = MHD_gnutls_malloc (sizeof (auth_cred_st));
if (pcred->next == NULL)
return GNUTLS_E_MEMORY_ERROR;
ccred = pcred->next;
/* copy credentials locally */
ccred->credentials = cred;
ccred->next = NULL;
ccred->algorithm = type;
}
else
{ /* modify existing entry */
MHD_gnutls_free (ccred->credentials);
ccred->credentials = cred;
}
}
return 0;
}
/**
* MHD_gtls_auth_get_type - Returns the type of credentials for the current authentication schema.
* @session: is a #MHD_gtls_session_t structure.
*
* Returns type of credentials for the current authentication schema.
* The returned information is to be used to distinguish the function used
* to access authentication data.
*
* Eg. for CERTIFICATE ciphersuites (key exchange algorithms: KX_RSA, KX_DHE_RSA),
* the same function are to be used to access the authentication data.
**/
enum MHD_GNUTLS_CredentialsType
MHD_gtls_auth_get_type (MHD_gtls_session_t session)
{
/* This is not the credentials we must set, but the authentication data
* we get by the peer, so it should be reversed.
*/
int server = session->security_parameters.entity == GNUTLS_SERVER ? 0 : 1;
return
MHD_gtls_map_kx_get_cred (MHD_gtls_cipher_suite_get_kx_algo
(&session->
security_parameters.current_cipher_suite),
server);
}
/*
* This returns a pointer to the linked list. Don't
* free that!!!
*/
const void *
MHD_gtls_get_kx_cred (MHD_gtls_session_t session,
enum MHD_GNUTLS_KeyExchangeAlgorithm algo, int *err)
{
int server = session->security_parameters.entity == GNUTLS_SERVER ? 1 : 0;
return MHD_gtls_get_cred (session->key,
MHD_gtls_map_kx_get_cred (algo, server), err);
}
const void *
MHD_gtls_get_cred (MHD_gtls_key_st key, enum MHD_GNUTLS_CredentialsType type,
int *err)
{
const void *retval = NULL;
int _err = -1;
auth_cred_st *ccred;
if (key == NULL)
goto out;
ccred = key->cred;
while (ccred != NULL)
{
if (ccred->algorithm == type)
{
break;
}
ccred = ccred->next;
}
if (ccred == NULL)
goto out;
_err = 0;
retval = ccred->credentials;
out:
if (err != NULL)
*err = _err;
return retval;
}
/*-
* MHD_gtls_get_auth_info - Returns a pointer to authentication information.
* @session: is a #MHD_gtls_session_t structure.
*
* This function must be called after a succesful MHD__gnutls_handshake().
* Returns a pointer to authentication information. That information
* is data obtained by the handshake protocol, the key exchange algorithm,
* and the TLS extensions messages.
*
* In case of GNUTLS_CRD_CERTIFICATE returns a type of &cert_auth_info_t;
* In case of GNUTLS_CRD_SRP returns a type of &srp_(server/client)_auth_info_t;
-*/
void *
MHD_gtls_get_auth_info (MHD_gtls_session_t session)
{
return session->key->auth_info;
}
/*-
* MHD_gtls_free_auth_info - Frees the auth info structure
* @session: is a #MHD_gtls_session_t structure.
*
* This function frees the auth info structure and sets it to
* null. It must be called since some structures contain malloced
* elements.
-*/
void
MHD_gtls_free_auth_info (MHD_gtls_session_t session)
{
MHD_gtls_dh_info_st *dh_info;
rsa_info_st *rsa_info;
if (session == NULL || session->key == NULL)
{
MHD_gnutls_assert ();
return;
}
switch (session->key->auth_info_type)
{
case MHD_GNUTLS_CRD_CERTIFICATE:
{
unsigned int i;
cert_auth_info_t info = MHD_gtls_get_auth_info (session);
if (info == NULL)
break;
dh_info = &info->dh;
rsa_info = &info->rsa_export;
for (i = 0; i < info->ncerts; i++)
{
MHD__gnutls_free_datum (&info->raw_certificate_list[i]);
}
MHD_gnutls_free (info->raw_certificate_list);
info->raw_certificate_list = NULL;
info->ncerts = 0;
MHD_gtls_free_dh_info (dh_info);
MHD_gtls_free_rsa_info (rsa_info);
}
break;
default:
return;
}
MHD_gnutls_free (session->key->auth_info);
session->key->auth_info = NULL;
session->key->auth_info_size = 0;
session->key->auth_info_type = 0;
}
/* This function will set the auth info structure in the key
* structure.
* If allow change is !=0 then this will allow changing the auth
* info structure to a different type.
*/
int
MHD_gtls_auth_info_set (MHD_gtls_session_t session,
enum MHD_GNUTLS_CredentialsType type, int size,
int allow_change)
{
if (session->key->auth_info == NULL)
{
session->key->auth_info = MHD_gnutls_calloc (1, size);
if (session->key->auth_info == NULL)
{
MHD_gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
session->key->auth_info_type = type;
session->key->auth_info_size = size;
}
else
{
if (allow_change == 0)
{
/* If the credentials for the current authentication scheme,
* are not the one we want to set, then it's an error.
* This may happen if a rehandshake is performed an the
* ciphersuite which is negotiated has different authentication
* schema.
*/
if (MHD_gtls_auth_get_type (session) !=
session->key->auth_info_type)
{
MHD_gnutls_assert ();
return GNUTLS_E_INVALID_REQUEST;
}
}
else
{
/* The new behaviour: Here we reallocate the auth info structure
* in order to be able to negotiate different authentication
* types. Ie. perform an auth_anon and then authenticate again using a
* certificate (in order to prevent revealing the certificate's contents,
* to passive eavesdropers.
*/
if (MHD_gtls_auth_get_type (session) !=
session->key->auth_info_type)
{
MHD_gtls_free_auth_info (session);
session->key->auth_info = calloc (1, size);
if (session->key->auth_info == NULL)
{
MHD_gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
session->key->auth_info_type = type;
session->key->auth_info_size = size;
}
}
}
return 0;
}
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