/*
* Copyright (C) 2005, 2006, 2008 Free Software Foundation
*
* Author: Simon Josefsson
*
* This file is part of GNUTLS-EXTRA.
*
* GNUTLS-EXTRA 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 of the License, or
* (at your option) any later version.
*
* GNUTLS-EXTRA 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 this program. If not, see .
*/
#include "gnutls_int.h"
#include "gnutls_record.h"
#include "gnutls_errors.h"
#include "gnutls_num.h"
#include "gnutls_state.h"
#include
#define CHECKSUM_SIZE 12
struct gnutls_ia_client_credentials_st
{
gnutls_ia_avp_func avp_func;
void *avp_ptr;
};
struct gnutls_ia_server_credentials_st
{
gnutls_ia_avp_func avp_func;
void *avp_ptr;
};
static const char server_finished_label[] = "server phase finished";
static const char client_finished_label[] = "client phase finished";
static const char inner_permutation_label[] = "inner secret permutation";
static const char challenge_label[] = "inner application challenge";
/*
* The TLS/IA packet is the InnerApplication token, described as
* follows in draft-funk-tls-inner-application-extension-01.txt:
*
* enum {
* application_payload(0), intermediate_phase_finished(1),
* final_phase_finished(2), (255)
* } InnerApplicationType;
*
* struct {
* InnerApplicationType msg_type;
* uint24 length;
* select (InnerApplicationType) {
* case application_payload: ApplicationPayload;
* case intermediate_phase_finished: IntermediatePhaseFinished;
* case final_phase_finished: FinalPhaseFinished;
* } body;
* } InnerApplication;
*
*/
/* Send TLS/IA data. If data==NULL && sizeofdata==NULL, then the last
send was interrupted for some reason, and then we try to send it
again. Returns the number of bytes sent, or an error code. If
this return E_AGAIN and E_INTERRUPTED, call this function again
with data==NULL&&sizeofdata=0NULL until it returns successfully. */
static ssize_t
_gnutls_send_inner_application (gnutls_session_t session,
gnutls_ia_apptype_t msg_type,
const char *data, size_t sizeofdata)
{
opaque *p = NULL;
size_t plen = 0;
ssize_t len;
if (data != NULL)
{
plen = sizeofdata + 4;
p = gnutls_malloc (plen);
if (!p)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
*(unsigned char *) p = (unsigned char) (msg_type & 0xFF);
_gnutls_write_uint24 (sizeofdata, p + 1);
memcpy (p + 4, data, sizeofdata);
}
len = _gnutls_send_int (session, GNUTLS_INNER_APPLICATION, -1, p, plen);
if (p)
gnutls_free (p);
return len;
}
/* Receive TLS/IA data. Store received TLS/IA message type in
*MSG_TYPE, and the data in DATA of max SIZEOFDATA size. Return the
number of bytes read, or an error code. */
static ssize_t
_gnutls_recv_inner_application (gnutls_session_t session,
gnutls_ia_apptype_t * msg_type,
opaque * data, size_t sizeofdata)
{
ssize_t len;
uint32_t len24;
opaque pkt[4];
len = _gnutls_recv_int (session, GNUTLS_INNER_APPLICATION, -1, pkt, 4);
if (len != 4)
{
gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
*msg_type = pkt[0];
len24 = _gnutls_read_uint24 (&pkt[1]);
if (*msg_type != GNUTLS_IA_APPLICATION_PAYLOAD && len24 != CHECKSUM_SIZE)
{
gnutls_assert ();
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
if (sizeofdata < len24)
{
/* XXX push back pkt to IA buffer? */
gnutls_assert ();
return GNUTLS_E_SHORT_MEMORY_BUFFER;
}
if (len24 > 0)
{
uint32_t tmplen = len24;
len24 = _gnutls_recv_int (session, GNUTLS_INNER_APPLICATION, -1,
data, tmplen);
if (len24 != tmplen)
{
gnutls_assert ();
/* XXX Correct? */
return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
}
}
return len24;
}
/* Apply the TLS PRF using the TLS/IA inner secret as keying material,
where the seed is the client random concatenated with the server
random concatenated EXTRA of EXTRA_SIZE length (which can be NULL/0
respectively). LABEL and LABEL_SIZE is used as the label. The
result is placed in pre-allocated OUT of OUTSIZE length. */
static int
_gnutls_ia_prf (gnutls_session_t session,
size_t label_size,
const char *label,
size_t extra_size,
const char *extra, size_t outsize, opaque * out)
{
int ret;
opaque *seed;
size_t seedsize = 2 * GNUTLS_RANDOM_SIZE + extra_size;
seed = gnutls_malloc (seedsize);
if (!seed)
{
gnutls_assert ();
return GNUTLS_E_MEMORY_ERROR;
}
memcpy (seed, session->security_parameters.server_random,
GNUTLS_RANDOM_SIZE);
memcpy (seed + GNUTLS_RANDOM_SIZE,
session->security_parameters.client_random, GNUTLS_RANDOM_SIZE);
memcpy (seed + 2 * GNUTLS_RANDOM_SIZE, extra, extra_size);
ret = _gnutls_PRF (session, session->security_parameters.inner_secret,
GNUTLS_MASTER_SIZE,
label, label_size, seed, seedsize, outsize, out);
gnutls_free (seed);
return ret;
}
/**
* gnutls_ia_permute_inner_secret:
* @session: is a #gnutls_session_t structure.
* @session_keys_size: Size of generated session keys (0 if none).
* @session_keys: Generated session keys, used to permute inner secret
* (NULL if none).
*
* Permute the inner secret using the generated session keys.
*
* This can be called in the TLS/IA AVP callback to mix any generated
* session keys with the TLS/IA inner secret.
*
* Return value: Return zero on success, or a negative error code.
**/
int
gnutls_ia_permute_inner_secret (gnutls_session_t session,
size_t session_keys_size,
const char *session_keys)
{
return _gnutls_ia_prf (session,
sizeof (inner_permutation_label) - 1,
inner_permutation_label,
session_keys_size,
session_keys,
GNUTLS_RANDOM_SIZE,
session->security_parameters.inner_secret);
}
/**
* gnutls_ia_generate_challenge:
* @session: is a #gnutls_session_t structure.
* @buffer_size: size of output buffer.
* @buffer: pre-allocated buffer to contain @buffer_size bytes of output.
*
* Generate an application challenge that the client cannot control or
* predict, based on the TLS/IA inner secret.
*
* Return value: Returns 0 on success, or an negative error code.
**/
int
gnutls_ia_generate_challenge (gnutls_session_t session,
size_t buffer_size, char *buffer)
{
return _gnutls_ia_prf (session,
sizeof (challenge_label) - 1,
challenge_label, 0, NULL, buffer_size, buffer);
}
/**
* gnutls_ia_extract_inner_secret:
* @session: is a #gnutls_session_t structure.
* @buffer: pre-allocated buffer to hold 48 bytes of inner secret.
*
* Copy the 48 bytes large inner secret into the specified buffer
*
* This function is typically used after the TLS/IA handshake has
* concluded. The TLS/IA inner secret can be used as input to a PRF
* to derive session keys. Do not use the inner secret directly as a
* session key, because for a resumed session that does not include an
* application phase, the inner secret will be identical to the inner
* secret in the original session. It is important to include, for
* example, the client and server randomness when deriving a sesssion
* key from the inner secret.
**/
void
gnutls_ia_extract_inner_secret (gnutls_session_t session, char *buffer)
{
memcpy (buffer, session->security_parameters.inner_secret,
GNUTLS_MASTER_SIZE);
}
/**
* gnutls_ia_endphase_send:
* @session: is a #gnutls_session_t structure.
* @final_p: Set iff this should signal the final phase.
*
* Send a TLS/IA end phase message.
*
* In the client, this should only be used to acknowledge an end phase
* message sent by the server.
*
* In the server, this can be called instead of gnutls_ia_send() if
* the server wishes to end an application phase.
*
* Return value: Return 0 on success, or an error code.
**/
int
gnutls_ia_endphase_send (gnutls_session_t session, int final_p)
{
opaque local_checksum[CHECKSUM_SIZE];
int client = session->security_parameters.entity == GNUTLS_CLIENT;
const char *label = client ? client_finished_label : server_finished_label;
int size_of_label = client ? sizeof (client_finished_label) :
sizeof (server_finished_label);
ssize_t len;
int ret;
ret = _gnutls_PRF (session, session->security_parameters.inner_secret,
GNUTLS_MASTER_SIZE, label, size_of_label - 1,
/* XXX specification unclear on seed. */
"", 0, CHECKSUM_SIZE, local_checksum);
if (ret < 0)
return ret;
len = _gnutls_send_inner_application
(session,
final_p ? GNUTLS_IA_FINAL_PHASE_FINISHED :
GNUTLS_IA_INTERMEDIATE_PHASE_FINISHED, local_checksum, CHECKSUM_SIZE);
/* XXX Instead of calling this function over and over...?
* while (len == GNUTLS_E_AGAIN || len == GNUTLS_E_INTERRUPTED)
* len = _gnutls_io_write_flush(session);
*/
if (len < 0)
{
gnutls_assert ();
return len;
}
return 0;
}
/**
* gnutls_ia_verify_endphase:
* @session: is a #gnutls_session_t structure.
* @checksum: 12-byte checksum data, received from gnutls_ia_recv().
*
* Verify TLS/IA end phase checksum data. If verification fails, the
* %GNUTLS_A_INNER_APPLICATION_VERIFICATION alert is sent to the other
* sie.
*
* This function is called when gnutls_ia_recv() return
* %GNUTLS_E_WARNING_IA_IPHF_RECEIVED or
* %GNUTLS_E_WARNING_IA_FPHF_RECEIVED.
*
* Return value: Return 0 on successful verification, or an error
* code. If the checksum verification of the end phase message fails,
* %GNUTLS_E_IA_VERIFY_FAILED is returned.
**/
int
gnutls_ia_verify_endphase (gnutls_session_t session, const char *checksum)
{
char local_checksum[CHECKSUM_SIZE];
int client = session->security_parameters.entity == GNUTLS_CLIENT;
const char *label = client ? server_finished_label : client_finished_label;
int size_of_label = client ? sizeof (server_finished_label) :
sizeof (client_finished_label);
int ret;
ret = _gnutls_PRF (session, session->security_parameters.inner_secret,
GNUTLS_MASTER_SIZE,
label, size_of_label - 1,
"", 0, CHECKSUM_SIZE, local_checksum);
if (ret < 0)
{
gnutls_assert ();
return ret;
}
if (memcmp (local_checksum, checksum, CHECKSUM_SIZE) != 0)
{
ret = gnutls_alert_send (session, GNUTLS_AL_FATAL,
GNUTLS_A_INNER_APPLICATION_VERIFICATION);
if (ret < 0)
{
gnutls_assert ();
return ret;
}
return GNUTLS_E_IA_VERIFY_FAILED;
}
return 0;
}
/**
* gnutls_ia_send: Send peer the specified TLS/IA data.
* @session: is a #gnutls_session_t structure.
* @data: contains the data to send
* @sizeofdata: is the length of the data
*
* Send TLS/IA application payload data. This function has the
* similar semantics with send(). The only difference is that is
* accepts a GNUTLS session, and uses different error codes.
*
* The TLS/IA protocol is synchronous, so you cannot send more than
* one packet at a time. The client always send the first packet.
*
* To finish an application phase in the server, use
* gnutls_ia_endphase_send(). The client cannot end an application
* phase unilaterally; rather, a client is required to respond with an
* endphase of its own if gnutls_ia_recv indicates that the server has
* sent one.
*
* If the EINTR is returned by the internal push function (the default
* is send()} then %GNUTLS_E_INTERRUPTED will be returned. If
* %GNUTLS_E_INTERRUPTED or %GNUTLS_E_AGAIN is returned, you must call
* this function again, with the same parameters; alternatively you
* could provide a %NULL pointer for data, and 0 for size.
*
* Returns: The number of bytes sent, or a negative error code.
**/
ssize_t
gnutls_ia_send (gnutls_session_t session, const char *data, size_t sizeofdata)
{
ssize_t len;
len = _gnutls_send_inner_application (session,
GNUTLS_IA_APPLICATION_PAYLOAD,
data, sizeofdata);
return len;
}
/**
* gnutls_ia_recv - read data from the TLS/IA protocol
* @session: is a #gnutls_session_t structure.
* @data: the buffer that the data will be read into, must hold >= 12 bytes.
* @sizeofdata: the number of requested bytes, must be >= 12.
*
* Receive TLS/IA data. This function has the similar semantics with
* recv(). The only difference is that is accepts a GNUTLS session,
* and uses different error codes.
*
* If the server attempt to finish an application phase, this function
* will return %GNUTLS_E_WARNING_IA_IPHF_RECEIVED or
* %GNUTLS_E_WARNING_IA_FPHF_RECEIVED. The caller should then invoke
* gnutls_ia_verify_endphase(), and if it runs the client side, also
* send an endphase message of its own using gnutls_ia_endphase_send.
*
* If EINTR is returned by the internal push function (the default is
* @code{recv()}) then GNUTLS_E_INTERRUPTED will be returned. If
* GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN is returned, you must call
* this function again, with the same parameters; alternatively you
* could provide a NULL pointer for data, and 0 for size.
*
* Returns: The number of bytes received. A negative error code is
* returned in case of an error. The
* %GNUTLS_E_WARNING_IA_IPHF_RECEIVED and
* %GNUTLS_E_WARNING_IA_FPHF_RECEIVED errors are returned when an
* application phase finished message has been sent by the server.
**/
ssize_t
gnutls_ia_recv (gnutls_session_t session, char *data, size_t sizeofdata)
{
gnutls_ia_apptype_t msg_type = 0;
ssize_t len;
len = _gnutls_recv_inner_application (session, &msg_type, data, sizeofdata);
if (msg_type == GNUTLS_IA_INTERMEDIATE_PHASE_FINISHED)
return GNUTLS_E_WARNING_IA_IPHF_RECEIVED;
else if (msg_type == GNUTLS_IA_FINAL_PHASE_FINISHED)
return GNUTLS_E_WARNING_IA_FPHF_RECEIVED;
return len;
}
/* XXX rewrite the following two functions as state machines, to
handle EAGAIN/EINTERRUPTED? just add more problems to callers,
though. */
static int
_gnutls_ia_client_handshake (gnutls_session_t session)
{
char *buf = NULL;
size_t buflen = 0;
char tmp[1024]; /* XXX */
ssize_t len;
int ret;
const struct gnutls_ia_client_credentials_st *cred =
_gnutls_get_cred (session->key, GNUTLS_CRD_IA, NULL);
if (cred == NULL)
return GNUTLS_E_INTERNAL_ERROR;
while (1)
{
char *avp;
size_t avplen;
ret = cred->avp_func (session, cred->avp_ptr,
buf, buflen, &avp, &avplen);
if (ret)
{
int tmpret;
tmpret = gnutls_alert_send (session, GNUTLS_AL_FATAL,
GNUTLS_A_INNER_APPLICATION_FAILURE);
if (tmpret < 0)
gnutls_assert ();
return ret;
}
len = gnutls_ia_send (session, avp, avplen);
gnutls_free (avp);
if (len < 0)
return len;
len = gnutls_ia_recv (session, tmp, sizeof (tmp));
if (len == GNUTLS_E_WARNING_IA_IPHF_RECEIVED ||
len == GNUTLS_E_WARNING_IA_FPHF_RECEIVED)
{
ret = gnutls_ia_verify_endphase (session, tmp);
if (ret < 0)
return ret;
ret = gnutls_ia_endphase_send
(session, len == GNUTLS_E_WARNING_IA_FPHF_RECEIVED);
if (ret < 0)
return ret;
}
if (len == GNUTLS_E_WARNING_IA_IPHF_RECEIVED)
{
buf = NULL;
buflen = 0;
continue;
}
else if (len == GNUTLS_E_WARNING_IA_FPHF_RECEIVED)
break;
if (len < 0)
return len;
buflen = len;
buf = tmp;
}
return 0;
}
static int
_gnutls_ia_server_handshake (gnutls_session_t session)
{
gnutls_ia_apptype_t msg_type;
ssize_t len;
char buf[1024];
int ret;
const struct gnutls_ia_server_credentials_st *cred =
_gnutls_get_cred (session->key, GNUTLS_CRD_IA, NULL);
if (cred == NULL)
return GNUTLS_E_INTERNAL_ERROR;
do
{
char *avp;
size_t avplen;
len = gnutls_ia_recv (session, buf, sizeof (buf));
if (len == GNUTLS_E_WARNING_IA_IPHF_RECEIVED ||
len == GNUTLS_E_WARNING_IA_FPHF_RECEIVED)
{
ret = gnutls_ia_verify_endphase (session, buf);
if (ret < 0)
return ret;
}
if (len == GNUTLS_E_WARNING_IA_IPHF_RECEIVED)
continue;
else if (len == GNUTLS_E_WARNING_IA_FPHF_RECEIVED)
break;
if (len < 0)
return len;
avp = NULL;
avplen = 0;
ret = cred->avp_func (session, cred->avp_ptr, buf, len, &avp, &avplen);
if (ret < 0)
{
int tmpret;
tmpret = gnutls_alert_send (session, GNUTLS_AL_FATAL,
GNUTLS_A_INNER_APPLICATION_FAILURE);
if (tmpret < 0)
gnutls_assert ();
return ret;
}
msg_type = ret;
if (msg_type != GNUTLS_IA_APPLICATION_PAYLOAD)
{
ret = gnutls_ia_endphase_send (session, msg_type ==
GNUTLS_IA_FINAL_PHASE_FINISHED);
if (ret < 0)
return ret;
}
else
{
len = gnutls_ia_send (session, avp, avplen);
gnutls_free (avp);
if (len < 0)
return len;
}
}
while (1);
return 0;
}
/**
* gnutls_ia_handshake_p:
* @session: is a #gnutls_session_t structure.
*
* Predicate to be used after gnutls_handshake() to decide whether to
* invoke gnutls_ia_handshake(). Usable by both clients and servers.
*
* Return value: non-zero if TLS/IA handshake is expected, zero
* otherwise.
**/
int
gnutls_ia_handshake_p (gnutls_session_t session)
{
tls_ext_st *ext = &session->security_parameters.extensions;
/* Either local side or peer doesn't do TLS/IA: don't do IA */
if (!ext->gnutls_ia_enable || !ext->gnutls_ia_peer_enable)
return 0;
/* Not resuming or we don't allow skipping on resumption locally: do IA */
if (!ext->gnutls_ia_allowskip || !gnutls_session_is_resumed (session))
return 1;
/* If we're resuming and we and the peer both allow skipping on resumption:
* don't do IA */
return !ext->gnutls_ia_peer_allowskip;
}
/**
* gnutls_ia_handshake:
* @session: is a #gnutls_session_t structure.
*
* Perform a TLS/IA handshake. This should be called after
* gnutls_handshake() iff gnutls_ia_handshake_p().
*
* Return 0 on success, or an error code.
**/
int
gnutls_ia_handshake (gnutls_session_t session)
{
int ret;
if (session->security_parameters.entity == GNUTLS_CLIENT)
ret = _gnutls_ia_client_handshake (session);
else
ret = _gnutls_ia_server_handshake (session);
return ret;
}
/**
* gnutls_ia_allocate_client_credentials - Used to allocate an gnutls_ia_server_credentials_t structure
* @sc: is a pointer to an #gnutls_ia_server_credentials_t structure.
*
* This structure is complex enough to manipulate directly thus this
* helper function is provided in order to allocate it.
*
* Adding this credential to a session will enable TLS/IA, and will
* require an Application Phase after the TLS handshake (if the server
* support TLS/IA). Use gnutls_ia_require_inner_phase() to toggle the
* TLS/IA mode.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_ia_allocate_client_credentials (gnutls_ia_client_credentials_t * sc)
{
*sc = gnutls_calloc (1, sizeof (**sc));
if (*sc == NULL)
return GNUTLS_E_MEMORY_ERROR;
return 0;
}
/**
* gnutls_ia_free_client_credentials - Used to free an allocated #gnutls_ia_client_credentials_t structure
* @sc: is an #gnutls_ia_client_credentials_t structure.
*
* This structure is complex enough to manipulate directly thus this
* helper function is provided in order to free (deallocate) it.
*
**/
void
gnutls_ia_free_client_credentials (gnutls_ia_client_credentials_t sc)
{
gnutls_free (sc);
}
/**
* gnutls_ia_set_client_avp_function - Used to set a AVP callback
* @cred: is a #gnutls_ia_client_credentials_t structure.
* @avp_func: is the callback function
*
* Set the TLS/IA AVP callback handler used for the session.
*
* The AVP callback is called to process AVPs received from the
* server, and to get a new AVP to send to the server.
*
* The callback's function form is:
* int (*avp_func) (gnutls_session_t session, void *ptr,
* const char *last, size_t lastlen,
* char **next, size_t *nextlen);
*
* The @session parameter is the #gnutls_session_t structure
* corresponding to the current session. The @ptr parameter is the
* application hook pointer, set through
* gnutls_ia_set_client_avp_ptr(). The AVP received from the server
* is present in @last of @lastlen size, which will be %NULL on the
* first invocation. The newly allocated output AVP to send to the
* server should be placed in *@next of *@nextlen size.
*
* The callback may invoke gnutls_ia_permute_inner_secret() to mix any
* generated session keys with the TLS/IA inner secret.
*
* Return 0 (%GNUTLS_IA_APPLICATION_PAYLOAD) on success, or a negative
* error code to abort the TLS/IA handshake.
*
* Note that the callback must use allocate the @next parameter using
* gnutls_malloc(), because it is released via gnutls_free() by the
* TLS/IA handshake function.
*
**/
void
gnutls_ia_set_client_avp_function (gnutls_ia_client_credentials_t cred,
gnutls_ia_avp_func avp_func)
{
cred->avp_func = avp_func;
}
/**
* gnutls_ia_set_client_avp_ptr - Sets a pointer to be sent to TLS/IA callback
* @cred: is a #gnutls_ia_client_credentials_t structure.
* @ptr: is the pointer
*
* Sets the pointer that will be provided to the TLS/IA callback
* function as the first argument.
**/
void
gnutls_ia_set_client_avp_ptr (gnutls_ia_client_credentials_t cred, void *ptr)
{
cred->avp_ptr = ptr;
}
/**
* gnutls_ia_get_client_avp_ptr - Returns the pointer which is sent to TLS/IA callback
* @cred: is a #gnutls_ia_client_credentials_t structure.
*
* Returns the pointer that will be provided to the TLS/IA callback
* function as the first argument.
*
* Returns: The client callback data pointer.
**/
void *
gnutls_ia_get_client_avp_ptr (gnutls_ia_client_credentials_t cred)
{
return cred->avp_ptr;
}
/**
* gnutls_ia_allocate_server_credentials - Used to allocate an gnutls_ia_server_credentials_t structure
* @sc: is a pointer to an #gnutls_ia_server_credentials_t structure.
*
* This structure is complex enough to manipulate directly thus this
* helper function is provided in order to allocate it.
*
* Adding this credential to a session will enable TLS/IA, and will
* require an Application Phase after the TLS handshake (if the client
* support TLS/IA). Use gnutls_ia_require_inner_phase() to toggle the
* TLS/IA mode.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
* an error code is returned.
**/
int
gnutls_ia_allocate_server_credentials (gnutls_ia_server_credentials_t * sc)
{
*sc = gnutls_calloc (1, sizeof (**sc));
if (*sc == NULL)
return GNUTLS_E_MEMORY_ERROR;
return 0;
}
/**
* gnutls_ia_free_server_credentials - Used to free an allocated #gnutls_ia_server_credentials_t structure
* @sc: is an #gnutls_ia_server_credentials_t structure.
*
* This structure is complex enough to manipulate directly thus this
* helper function is provided in order to free (deallocate) it.
*
**/
void
gnutls_ia_free_server_credentials (gnutls_ia_server_credentials_t sc)
{
gnutls_free (sc);
}
/**
* gnutls_ia_set_server_credentials_function - Used to set a AVP callback
* @cred: is a #gnutls_ia_server_credentials_t structure.
* @func: is the callback function
*
* Set the TLS/IA AVP callback handler used for the session.
*
* The callback's function form is:
* int (*avp_func) (gnutls_session_t session, void *ptr,
* const char *last, size_t lastlen,
* char **next, size_t *nextlen);
*
* The @session parameter is the #gnutls_session_t structure
* corresponding to the current session. The @ptr parameter is the
* application hook pointer, set through
* gnutls_ia_set_server_avp_ptr(). The AVP received from the client
* is present in @last of @lastlen size. The newly allocated output
* AVP to send to the client should be placed in *@next of *@nextlen
* size.
*
* The AVP callback is called to process incoming AVPs from the
* client, and to get a new AVP to send to the client. It can also be
* used to instruct the TLS/IA handshake to do go into the
* Intermediate or Final phases. It return a negative error code, or
* an #gnutls_ia_apptype_t message type.
*
* The callback may invoke gnutls_ia_permute_inner_secret() to mix any
* generated session keys with the TLS/IA inner secret.
*
* Specifically, return %GNUTLS_IA_APPLICATION_PAYLOAD (0) to send
* another AVP to the client, return
* %GNUTLS_IA_INTERMEDIATE_PHASE_FINISHED (1) to indicate that an
* IntermediatePhaseFinished message should be sent, and return
* %GNUTLS_IA_FINAL_PHASE_FINISHED (2) to indicate that an
* FinalPhaseFinished message should be sent. In the last two cases,
* the contents of the @next and @nextlen parameter is not used.
*
* Note that the callback must use allocate the @next parameter using
* gnutls_malloc(), because it is released via gnutls_free() by the
* TLS/IA handshake function.
**/
void
gnutls_ia_set_server_avp_function (gnutls_ia_server_credentials_t cred,
gnutls_ia_avp_func avp_func)
{
cred->avp_func = avp_func;
}
/**
* gnutls_ia_set_server_avp_ptr - Sets a pointer to be sent to TLS/IA callback
* @cred: is a #gnutls_ia_client_credentials_t structure.
* @ptr: is the pointer
*
* Sets the pointer that will be provided to the TLS/IA callback
* function as the first argument.
**/
void
gnutls_ia_set_server_avp_ptr (gnutls_ia_server_credentials_t cred, void *ptr)
{
cred->avp_ptr = ptr;
}
/**
* gnutls_ia_get_server_avp_ptr - Returns the pointer which is sent to TLS/IA callback
* @cred: is a #gnutls_ia_client_credentials_t structure.
*
* Returns the pointer that will be provided to the TLS/IA callback
* function as the first argument.
*
* Returns: The server callback data pointer.
**/
void *
gnutls_ia_get_server_avp_ptr (gnutls_ia_server_credentials_t cred)
{
return cred->avp_ptr;
}
/**
* gnutls_ia_enable - Indicate willingness for TLS/IA application phases
* @session: is a #gnutls_session_t structure.
* @allow_skip_on_resume: non-zero if local party allows to skip the
* TLS/IA application phases for a resumed session.
*
* Specify whether we must advertise support for the TLS/IA extension
* during the handshake.
*
* At the client side, we always advertise TLS/IA if gnutls_ia_enable
* was called before the handshake; at the server side, we also
* require that the client has advertised that it wants to run TLS/IA
* before including the advertisement, as required by the protocol.
*
* Similarly, at the client side we always advertise that we allow
* TLS/IA to be skipped for resumed sessions if @allow_skip_on_resume
* is non-zero; at the server side, we also require that the session
* is indeed resumable and that the client has also advertised that it
* allows TLS/IA to be skipped for resumed sessions.
*
* After the TLS handshake, call gnutls_ia_handshake_p() to find out
* whether both parties agreed to do a TLS/IA handshake, before
* calling gnutls_ia_handshake() or one of the lower level gnutls_ia_*
* functions.
**/
void
gnutls_ia_enable (gnutls_session_t session, int allow_skip_on_resume)
{
session->security_parameters.extensions.gnutls_ia_enable = 1;
session->security_parameters.extensions.gnutls_ia_allowskip =
allow_skip_on_resume;
}