freebsd-skq/crypto/heimdal/lib/gssapi/krb5/init_sec_context.c
2008-05-07 13:39:42 +00:00

812 lines
19 KiB
C

/*
* Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5/gsskrb5_locl.h"
RCSID("$Id: init_sec_context.c 22071 2007-11-14 20:04:50Z lha $");
/*
* copy the addresses from `input_chan_bindings' (if any) to
* the auth context `ac'
*/
static OM_uint32
set_addresses (krb5_context context,
krb5_auth_context ac,
const gss_channel_bindings_t input_chan_bindings)
{
/* Port numbers are expected to be in application_data.value,
* initator's port first */
krb5_address initiator_addr, acceptor_addr;
krb5_error_code kret;
if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS
|| input_chan_bindings->application_data.length !=
2 * sizeof(ac->local_port))
return 0;
memset(&initiator_addr, 0, sizeof(initiator_addr));
memset(&acceptor_addr, 0, sizeof(acceptor_addr));
ac->local_port =
*(int16_t *) input_chan_bindings->application_data.value;
ac->remote_port =
*((int16_t *) input_chan_bindings->application_data.value + 1);
kret = _gsskrb5i_address_to_krb5addr(context,
input_chan_bindings->acceptor_addrtype,
&input_chan_bindings->acceptor_address,
ac->remote_port,
&acceptor_addr);
if (kret)
return kret;
kret = _gsskrb5i_address_to_krb5addr(context,
input_chan_bindings->initiator_addrtype,
&input_chan_bindings->initiator_address,
ac->local_port,
&initiator_addr);
if (kret) {
krb5_free_address (context, &acceptor_addr);
return kret;
}
kret = krb5_auth_con_setaddrs(context,
ac,
&initiator_addr, /* local address */
&acceptor_addr); /* remote address */
krb5_free_address (context, &initiator_addr);
krb5_free_address (context, &acceptor_addr);
#if 0
free(input_chan_bindings->application_data.value);
input_chan_bindings->application_data.value = NULL;
input_chan_bindings->application_data.length = 0;
#endif
return kret;
}
OM_uint32
_gsskrb5_create_ctx(
OM_uint32 * minor_status,
gss_ctx_id_t * context_handle,
krb5_context context,
const gss_channel_bindings_t input_chan_bindings,
enum gss_ctx_id_t_state state)
{
krb5_error_code kret;
gsskrb5_ctx ctx;
*context_handle = NULL;
ctx = malloc(sizeof(*ctx));
if (ctx == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
ctx->auth_context = NULL;
ctx->source = NULL;
ctx->target = NULL;
ctx->state = state;
ctx->flags = 0;
ctx->more_flags = 0;
ctx->service_keyblock = NULL;
ctx->ticket = NULL;
krb5_data_zero(&ctx->fwd_data);
ctx->lifetime = GSS_C_INDEFINITE;
ctx->order = NULL;
HEIMDAL_MUTEX_init(&ctx->ctx_id_mutex);
kret = krb5_auth_con_init (context, &ctx->auth_context);
if (kret) {
*minor_status = kret;
HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);
return GSS_S_FAILURE;
}
kret = set_addresses(context, ctx->auth_context, input_chan_bindings);
if (kret) {
*minor_status = kret;
HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);
krb5_auth_con_free(context, ctx->auth_context);
return GSS_S_BAD_BINDINGS;
}
/*
* We need a sequence number
*/
krb5_auth_con_addflags(context,
ctx->auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE |
KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED,
NULL);
*context_handle = (gss_ctx_id_t)ctx;
return GSS_S_COMPLETE;
}
static OM_uint32
gsskrb5_get_creds(
OM_uint32 * minor_status,
krb5_context context,
krb5_ccache ccache,
gsskrb5_ctx ctx,
krb5_const_principal target_name,
OM_uint32 time_req,
OM_uint32 * time_rec,
krb5_creds ** cred)
{
OM_uint32 ret;
krb5_error_code kret;
krb5_creds this_cred;
OM_uint32 lifetime_rec;
*cred = NULL;
memset(&this_cred, 0, sizeof(this_cred));
this_cred.client = ctx->source;
this_cred.server = ctx->target;
if (time_req && time_req != GSS_C_INDEFINITE) {
krb5_timestamp ts;
krb5_timeofday (context, &ts);
this_cred.times.endtime = ts + time_req;
} else {
this_cred.times.endtime = 0;
}
this_cred.session.keytype = KEYTYPE_NULL;
kret = krb5_get_credentials(context,
0,
ccache,
&this_cred,
cred);
if (kret) {
*minor_status = kret;
return GSS_S_FAILURE;
}
ctx->lifetime = (*cred)->times.endtime;
ret = _gsskrb5_lifetime_left(minor_status, context,
ctx->lifetime, &lifetime_rec);
if (ret) return ret;
if (lifetime_rec == 0) {
*minor_status = 0;
return GSS_S_CONTEXT_EXPIRED;
}
if (time_rec) *time_rec = lifetime_rec;
return GSS_S_COMPLETE;
}
static OM_uint32
gsskrb5_initiator_ready(
OM_uint32 * minor_status,
gsskrb5_ctx ctx,
krb5_context context)
{
OM_uint32 ret;
int32_t seq_number;
int is_cfx = 0;
OM_uint32 flags = ctx->flags;
krb5_auth_getremoteseqnumber (context,
ctx->auth_context,
&seq_number);
_gsskrb5i_is_cfx(ctx, &is_cfx);
ret = _gssapi_msg_order_create(minor_status,
&ctx->order,
_gssapi_msg_order_f(flags),
seq_number, 0, is_cfx);
if (ret) return ret;
ctx->state = INITIATOR_READY;
ctx->more_flags |= OPEN;
return GSS_S_COMPLETE;
}
/*
* handle delegated creds in init-sec-context
*/
static void
do_delegation (krb5_context context,
krb5_auth_context ac,
krb5_ccache ccache,
krb5_creds *cred,
krb5_const_principal name,
krb5_data *fwd_data,
uint32_t *flags)
{
krb5_creds creds;
KDCOptions fwd_flags;
krb5_error_code kret;
memset (&creds, 0, sizeof(creds));
krb5_data_zero (fwd_data);
kret = krb5_cc_get_principal(context, ccache, &creds.client);
if (kret)
goto out;
kret = krb5_build_principal(context,
&creds.server,
strlen(creds.client->realm),
creds.client->realm,
KRB5_TGS_NAME,
creds.client->realm,
NULL);
if (kret)
goto out;
creds.times.endtime = 0;
memset(&fwd_flags, 0, sizeof(fwd_flags));
fwd_flags.forwarded = 1;
fwd_flags.forwardable = 1;
if ( /*target_name->name.name_type != KRB5_NT_SRV_HST ||*/
name->name.name_string.len < 2)
goto out;
kret = krb5_get_forwarded_creds(context,
ac,
ccache,
KDCOptions2int(fwd_flags),
name->name.name_string.val[1],
&creds,
fwd_data);
out:
if (kret)
*flags &= ~GSS_C_DELEG_FLAG;
else
*flags |= GSS_C_DELEG_FLAG;
if (creds.client)
krb5_free_principal(context, creds.client);
if (creds.server)
krb5_free_principal(context, creds.server);
}
/*
* first stage of init-sec-context
*/
static OM_uint32
init_auth
(OM_uint32 * minor_status,
gsskrb5_cred initiator_cred_handle,
gsskrb5_ctx ctx,
krb5_context context,
krb5_const_principal name,
const gss_OID mech_type,
OM_uint32 req_flags,
OM_uint32 time_req,
const gss_channel_bindings_t input_chan_bindings,
const gss_buffer_t input_token,
gss_OID * actual_mech_type,
gss_buffer_t output_token,
OM_uint32 * ret_flags,
OM_uint32 * time_rec
)
{
OM_uint32 ret = GSS_S_FAILURE;
krb5_error_code kret;
krb5_flags ap_options;
krb5_creds *cred = NULL;
krb5_data outbuf;
krb5_ccache ccache = NULL;
uint32_t flags;
krb5_data authenticator;
Checksum cksum;
krb5_enctype enctype;
krb5_data fwd_data;
OM_uint32 lifetime_rec;
krb5_data_zero(&outbuf);
krb5_data_zero(&fwd_data);
*minor_status = 0;
if (actual_mech_type)
*actual_mech_type = GSS_KRB5_MECHANISM;
if (initiator_cred_handle == NULL) {
kret = krb5_cc_default (context, &ccache);
if (kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
} else
ccache = initiator_cred_handle->ccache;
kret = krb5_cc_get_principal (context, ccache, &ctx->source);
if (kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
kret = krb5_copy_principal (context, name, &ctx->target);
if (kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
ret = _gss_DES3_get_mic_compat(minor_status, ctx, context);
if (ret)
goto failure;
/*
* This is hideous glue for (NFS) clients that wants to limit the
* available enctypes to what it can support (encryption in
* kernel). If there is no enctypes selected for this credential,
* reset it to the default set of enctypes.
*/
{
krb5_enctype *enctypes = NULL;
if (initiator_cred_handle && initiator_cred_handle->enctypes)
enctypes = initiator_cred_handle->enctypes;
krb5_set_default_in_tkt_etypes(context, enctypes);
}
ret = gsskrb5_get_creds(minor_status,
context,
ccache,
ctx,
ctx->target,
time_req,
time_rec,
&cred);
if (ret)
goto failure;
ctx->lifetime = cred->times.endtime;
ret = _gsskrb5_lifetime_left(minor_status,
context,
ctx->lifetime,
&lifetime_rec);
if (ret) {
goto failure;
}
if (lifetime_rec == 0) {
*minor_status = 0;
ret = GSS_S_CONTEXT_EXPIRED;
goto failure;
}
krb5_auth_con_setkey(context,
ctx->auth_context,
&cred->session);
kret = krb5_auth_con_generatelocalsubkey(context,
ctx->auth_context,
&cred->session);
if(kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
/*
* If the credential doesn't have ok-as-delegate, check what local
* policy say about ok-as-delegate, default is FALSE that makes
* code ignore the KDC setting and follow what the application
* requested. If it is TRUE, strip of the GSS_C_DELEG_FLAG if the
* KDC doesn't set ok-as-delegate.
*/
if (!cred->flags.b.ok_as_delegate) {
krb5_boolean delegate;
krb5_appdefault_boolean(context,
"gssapi", name->realm,
"ok-as-delegate", FALSE, &delegate);
if (delegate)
req_flags &= ~GSS_C_DELEG_FLAG;
}
flags = 0;
ap_options = 0;
if (req_flags & GSS_C_DELEG_FLAG)
do_delegation (context,
ctx->auth_context,
ccache, cred, name, &fwd_data, &flags);
if (req_flags & GSS_C_MUTUAL_FLAG) {
flags |= GSS_C_MUTUAL_FLAG;
ap_options |= AP_OPTS_MUTUAL_REQUIRED;
}
if (req_flags & GSS_C_REPLAY_FLAG)
flags |= GSS_C_REPLAY_FLAG;
if (req_flags & GSS_C_SEQUENCE_FLAG)
flags |= GSS_C_SEQUENCE_FLAG;
if (req_flags & GSS_C_ANON_FLAG)
; /* XXX */
if (req_flags & GSS_C_DCE_STYLE) {
/* GSS_C_DCE_STYLE implies GSS_C_MUTUAL_FLAG */
flags |= GSS_C_DCE_STYLE | GSS_C_MUTUAL_FLAG;
ap_options |= AP_OPTS_MUTUAL_REQUIRED;
}
if (req_flags & GSS_C_IDENTIFY_FLAG)
flags |= GSS_C_IDENTIFY_FLAG;
if (req_flags & GSS_C_EXTENDED_ERROR_FLAG)
flags |= GSS_C_EXTENDED_ERROR_FLAG;
flags |= GSS_C_CONF_FLAG;
flags |= GSS_C_INTEG_FLAG;
flags |= GSS_C_TRANS_FLAG;
if (ret_flags)
*ret_flags = flags;
ctx->flags = flags;
ctx->more_flags |= LOCAL;
ret = _gsskrb5_create_8003_checksum (minor_status,
input_chan_bindings,
flags,
&fwd_data,
&cksum);
krb5_data_free (&fwd_data);
if (ret)
goto failure;
enctype = ctx->auth_context->keyblock->keytype;
kret = krb5_build_authenticator (context,
ctx->auth_context,
enctype,
cred,
&cksum,
NULL,
&authenticator,
KRB5_KU_AP_REQ_AUTH);
if (kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
kret = krb5_build_ap_req (context,
enctype,
cred,
ap_options,
authenticator,
&outbuf);
if (kret) {
*minor_status = kret;
ret = GSS_S_FAILURE;
goto failure;
}
ret = _gsskrb5_encapsulate (minor_status, &outbuf, output_token,
(u_char *)"\x01\x00", GSS_KRB5_MECHANISM);
if (ret)
goto failure;
krb5_data_free (&outbuf);
krb5_free_creds(context, cred);
free_Checksum(&cksum);
if (initiator_cred_handle == NULL)
krb5_cc_close(context, ccache);
if (flags & GSS_C_MUTUAL_FLAG) {
ctx->state = INITIATOR_WAIT_FOR_MUTAL;
return GSS_S_CONTINUE_NEEDED;
}
return gsskrb5_initiator_ready(minor_status, ctx, context);
failure:
if(cred)
krb5_free_creds(context, cred);
if (ccache && initiator_cred_handle == NULL)
krb5_cc_close(context, ccache);
return ret;
}
static OM_uint32
repl_mutual
(OM_uint32 * minor_status,
gsskrb5_ctx ctx,
krb5_context context,
const gss_OID mech_type,
OM_uint32 req_flags,
OM_uint32 time_req,
const gss_channel_bindings_t input_chan_bindings,
const gss_buffer_t input_token,
gss_OID * actual_mech_type,
gss_buffer_t output_token,
OM_uint32 * ret_flags,
OM_uint32 * time_rec
)
{
OM_uint32 ret;
krb5_error_code kret;
krb5_data indata;
krb5_ap_rep_enc_part *repl;
int is_cfx = 0;
output_token->length = 0;
output_token->value = NULL;
if (actual_mech_type)
*actual_mech_type = GSS_KRB5_MECHANISM;
if (ctx->flags & GSS_C_DCE_STYLE) {
/* There is no OID wrapping. */
indata.length = input_token->length;
indata.data = input_token->value;
} else {
ret = _gsskrb5_decapsulate (minor_status,
input_token,
&indata,
"\x02\x00",
GSS_KRB5_MECHANISM);
if (ret) {
/* XXX - Handle AP_ERROR */
return ret;
}
}
kret = krb5_rd_rep (context,
ctx->auth_context,
&indata,
&repl);
if (kret) {
*minor_status = kret;
return GSS_S_FAILURE;
}
krb5_free_ap_rep_enc_part (context,
repl);
_gsskrb5i_is_cfx(ctx, &is_cfx);
if (is_cfx) {
krb5_keyblock *key = NULL;
kret = krb5_auth_con_getremotesubkey(context,
ctx->auth_context,
&key);
if (kret == 0 && key != NULL) {
ctx->more_flags |= ACCEPTOR_SUBKEY;
krb5_free_keyblock (context, key);
}
}
*minor_status = 0;
if (time_rec) {
ret = _gsskrb5_lifetime_left(minor_status,
context,
ctx->lifetime,
time_rec);
} else {
ret = GSS_S_COMPLETE;
}
if (ret_flags)
*ret_flags = ctx->flags;
if (req_flags & GSS_C_DCE_STYLE) {
int32_t con_flags;
krb5_data outbuf;
/* Do don't do sequence number for the mk-rep */
krb5_auth_con_removeflags(context,
ctx->auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE,
&con_flags);
kret = krb5_mk_rep(context,
ctx->auth_context,
&outbuf);
if (kret) {
*minor_status = kret;
return GSS_S_FAILURE;
}
output_token->length = outbuf.length;
output_token->value = outbuf.data;
krb5_auth_con_removeflags(context,
ctx->auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE,
NULL);
}
return gsskrb5_initiator_ready(minor_status, ctx, context);
}
/*
* gss_init_sec_context
*/
OM_uint32 _gsskrb5_init_sec_context
(OM_uint32 * minor_status,
const gss_cred_id_t initiator_cred_handle,
gss_ctx_id_t * context_handle,
const gss_name_t target_name,
const gss_OID mech_type,
OM_uint32 req_flags,
OM_uint32 time_req,
const gss_channel_bindings_t input_chan_bindings,
const gss_buffer_t input_token,
gss_OID * actual_mech_type,
gss_buffer_t output_token,
OM_uint32 * ret_flags,
OM_uint32 * time_rec
)
{
krb5_context context;
gsskrb5_cred cred = (gsskrb5_cred)initiator_cred_handle;
krb5_const_principal name = (krb5_const_principal)target_name;
gsskrb5_ctx ctx;
OM_uint32 ret;
GSSAPI_KRB5_INIT (&context);
output_token->length = 0;
output_token->value = NULL;
if (context_handle == NULL) {
*minor_status = 0;
return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
}
if (ret_flags)
*ret_flags = 0;
if (time_rec)
*time_rec = 0;
if (target_name == GSS_C_NO_NAME) {
if (actual_mech_type)
*actual_mech_type = GSS_C_NO_OID;
*minor_status = 0;
return GSS_S_BAD_NAME;
}
if (mech_type != GSS_C_NO_OID &&
!gss_oid_equal(mech_type, GSS_KRB5_MECHANISM))
return GSS_S_BAD_MECH;
if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
OM_uint32 ret;
if (*context_handle != GSS_C_NO_CONTEXT) {
*minor_status = 0;
return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
}
ret = _gsskrb5_create_ctx(minor_status,
context_handle,
context,
input_chan_bindings,
INITIATOR_START);
if (ret)
return ret;
}
if (*context_handle == GSS_C_NO_CONTEXT) {
*minor_status = 0;
return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
}
ctx = (gsskrb5_ctx) *context_handle;
HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
switch (ctx->state) {
case INITIATOR_START:
ret = init_auth(minor_status,
cred,
ctx,
context,
name,
mech_type,
req_flags,
time_req,
input_chan_bindings,
input_token,
actual_mech_type,
output_token,
ret_flags,
time_rec);
break;
case INITIATOR_WAIT_FOR_MUTAL:
ret = repl_mutual(minor_status,
ctx,
context,
mech_type,
req_flags,
time_req,
input_chan_bindings,
input_token,
actual_mech_type,
output_token,
ret_flags,
time_rec);
break;
case INITIATOR_READY:
/*
* If we get there, the caller have called
* gss_init_sec_context() one time too many.
*/
*minor_status = 0;
ret = GSS_S_BAD_STATUS;
break;
default:
*minor_status = 0;
ret = GSS_S_BAD_STATUS;
break;
}
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
/* destroy context in case of error */
if (GSS_ERROR(ret)) {
OM_uint32 min2;
_gsskrb5_delete_sec_context(&min2, context_handle, GSS_C_NO_BUFFER);
}
return ret;
}