/* $NetBSD: init_sec_context.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */
/*
* Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* Portions Copyright (c) 2004 PADL Software Pty Ltd.
*
* 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 "spnego_locl.h"
/*
* Is target_name an sane target for `mech´.
*/
static OM_uint32
initiator_approved(gss_name_t target_name, gss_OID mech)
{
OM_uint32 min_stat, maj_stat;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_buffer_desc out;
maj_stat = gss_init_sec_context(&min_stat,
GSS_C_NO_CREDENTIAL,
&ctx,
target_name,
mech,
0,
GSS_C_INDEFINITE,
GSS_C_NO_CHANNEL_BINDINGS,
GSS_C_NO_BUFFER,
NULL,
&out,
NULL,
NULL);
if (GSS_ERROR(maj_stat)) {
gss_mg_collect_error(mech, maj_stat, min_stat);
return GSS_S_BAD_MECH;
}
gss_release_buffer(&min_stat, &out);
gss_delete_sec_context(&min_stat, &ctx, NULL);
return GSS_S_COMPLETE;
}
/*
* Send a reply. Note that we only need to send a reply if we
* need to send a MIC or a mechanism token. Otherwise, we can
* return an empty buffer.
*
* The return value of this will be returned to the API, so it
* must return GSS_S_CONTINUE_NEEDED if a token was generated.
*/
static OM_uint32
spnego_reply_internal(OM_uint32 *minor_status,
gssspnego_ctx context_handle,
const gss_buffer_t mech_buf,
gss_buffer_t mech_token,
gss_buffer_t output_token)
{
NegotiationToken nt;
gss_buffer_desc mic_buf;
OM_uint32 ret;
size_t size;
if (mech_buf == GSS_C_NO_BUFFER && mech_token->length == 0) {
output_token->length = 0;
output_token->value = NULL;
return context_handle->open ? GSS_S_COMPLETE : GSS_S_FAILURE;
}
memset(&nt, 0, sizeof(nt));
nt.element = choice_NegotiationToken_negTokenResp;
ALLOC(nt.u.negTokenResp.negResult, 1);
if (nt.u.negTokenResp.negResult == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
nt.u.negTokenResp.supportedMech = NULL;
output_token->length = 0;
output_token->value = NULL;
if (mech_token->length == 0) {
nt.u.negTokenResp.responseToken = NULL;
*(nt.u.negTokenResp.negResult) = accept_completed;
} else {
ALLOC(nt.u.negTokenResp.responseToken, 1);
if (nt.u.negTokenResp.responseToken == NULL) {
free_NegotiationToken(&nt);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
nt.u.negTokenResp.responseToken->length = mech_token->length;
nt.u.negTokenResp.responseToken->data = mech_token->value;
mech_token->length = 0;
mech_token->value = NULL;
*(nt.u.negTokenResp.negResult) = accept_incomplete;
}
if (mech_buf != GSS_C_NO_BUFFER) {
ret = gss_get_mic(minor_status,
context_handle->negotiated_ctx_id,
0,
mech_buf,
&mic_buf);
if (ret == GSS_S_COMPLETE) {
ALLOC(nt.u.negTokenResp.mechListMIC, 1);
if (nt.u.negTokenResp.mechListMIC == NULL) {
gss_release_buffer(minor_status, &mic_buf);
free_NegotiationToken(&nt);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
nt.u.negTokenResp.mechListMIC->length = mic_buf.length;
nt.u.negTokenResp.mechListMIC->data = mic_buf.value;
} else if (ret == GSS_S_UNAVAILABLE) {
nt.u.negTokenResp.mechListMIC = NULL;
} if (ret) {
free_NegotiationToken(&nt);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
} else {
nt.u.negTokenResp.mechListMIC = NULL;
}
ASN1_MALLOC_ENCODE(NegotiationToken,
output_token->value, output_token->length,
&nt, &size, ret);
if (ret) {
free_NegotiationToken(&nt);
*minor_status = ret;
return GSS_S_FAILURE;
}
if (*(nt.u.negTokenResp.negResult) == accept_completed)
ret = GSS_S_COMPLETE;
else
ret = GSS_S_CONTINUE_NEEDED;
free_NegotiationToken(&nt);
return ret;
}
static OM_uint32
spnego_initial
(OM_uint32 * minor_status,
gss_const_cred_id_t cred,
gss_ctx_id_t * context_handle,
gss_const_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
)
{
NegTokenInit ni;
int ret;
OM_uint32 sub, minor;
gss_buffer_desc mech_token;
u_char *buf;
size_t buf_size, buf_len;
gss_buffer_desc data;
size_t ni_len;
gss_ctx_id_t context;
gssspnego_ctx ctx;
spnego_name name = (spnego_name)target_name;
*minor_status = 0;
memset (&ni, 0, sizeof(ni));
*context_handle = GSS_C_NO_CONTEXT;
if (target_name == GSS_C_NO_NAME)
return GSS_S_BAD_NAME;
sub = _gss_spnego_alloc_sec_context(&minor, &context);
if (GSS_ERROR(sub)) {
*minor_status = minor;
return sub;
}
ctx = (gssspnego_ctx)context;
HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
ctx->local = 1;
sub = gss_import_name(&minor, &name->value, &name->type, &ctx->target_name);
if (GSS_ERROR(sub)) {
*minor_status = minor;
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return sub;
}
sub = _gss_spnego_indicate_mechtypelist(&minor,
ctx->target_name,
initiator_approved,
0,
cred,
&ni.mechTypes,
&ctx->preferred_mech_type);
if (GSS_ERROR(sub)) {
*minor_status = minor;
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return sub;
}
ni.reqFlags = NULL;
/*
* If we have a credential handle, use it to select the mechanism
* that we will use
*/
/* generate optimistic token */
sub = gss_init_sec_context(&minor,
cred,
&ctx->negotiated_ctx_id,
ctx->target_name,
ctx->preferred_mech_type,
req_flags,
time_req,
input_chan_bindings,
input_token,
&ctx->negotiated_mech_type,
&mech_token,
&ctx->mech_flags,
&ctx->mech_time_rec);
if (GSS_ERROR(sub)) {
free_NegTokenInit(&ni);
*minor_status = minor;
gss_mg_collect_error(ctx->preferred_mech_type, sub, minor);
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return sub;
}
if (sub == GSS_S_COMPLETE)
ctx->maybe_open = 1;
if (mech_token.length != 0) {
ALLOC(ni.mechToken, 1);
if (ni.mechToken == NULL) {
free_NegTokenInit(&ni);
gss_release_buffer(&minor, &mech_token);
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
ni.mechToken->length = mech_token.length;
ni.mechToken->data = malloc(mech_token.length);
if (ni.mechToken->data == NULL && mech_token.length != 0) {
free_NegTokenInit(&ni);
gss_release_buffer(&minor, &mech_token);
*minor_status = ENOMEM;
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return GSS_S_FAILURE;
}
memcpy(ni.mechToken->data, mech_token.value, mech_token.length);
gss_release_buffer(&minor, &mech_token);
} else
ni.mechToken = NULL;
ni.mechListMIC = NULL;
ni_len = length_NegTokenInit(&ni);
buf_size = 1 + der_length_len(ni_len) + ni_len;
buf = malloc(buf_size);
if (buf == NULL) {
free_NegTokenInit(&ni);
*minor_status = ENOMEM;
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return GSS_S_FAILURE;
}
ret = encode_NegTokenInit(buf + buf_size - 1,
ni_len,
&ni, &buf_len);
if (ret == 0 && ni_len != buf_len)
abort();
if (ret == 0) {
size_t tmp;
ret = der_put_length_and_tag(buf + buf_size - buf_len - 1,
buf_size - buf_len,
buf_len,
ASN1_C_CONTEXT,
CONS,
0,
&tmp);
if (ret == 0 && tmp + buf_len != buf_size)
abort();
}
if (ret) {
*minor_status = ret;
free(buf);
free_NegTokenInit(&ni);
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return GSS_S_FAILURE;
}
data.value = buf;
data.length = buf_size;
ctx->initiator_mech_types.len = ni.mechTypes.len;
ctx->initiator_mech_types.val = ni.mechTypes.val;
ni.mechTypes.len = 0;
ni.mechTypes.val = NULL;
free_NegTokenInit(&ni);
sub = gss_encapsulate_token(&data,
GSS_SPNEGO_MECHANISM,
output_token);
free (buf);
if (sub) {
_gss_spnego_internal_delete_sec_context(&minor, &context, GSS_C_NO_BUFFER);
return sub;
}
if (actual_mech_type)
*actual_mech_type = ctx->negotiated_mech_type;
if (ret_flags)
*ret_flags = ctx->mech_flags;
if (time_rec)
*time_rec = ctx->mech_time_rec;
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
*context_handle = context;
return GSS_S_CONTINUE_NEEDED;
}
static OM_uint32
spnego_reply
(OM_uint32 * minor_status,
gss_const_cred_id_t cred,
gss_ctx_id_t * context_handle,
gss_const_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
)
{
OM_uint32 ret, minor;
NegotiationToken resp;
gss_OID_desc mech;
int require_mic;
size_t buf_len = 0;
gss_buffer_desc mic_buf, mech_buf;
gss_buffer_desc mech_output_token;
gssspnego_ctx ctx;
*minor_status = 0;
ctx = (gssspnego_ctx)*context_handle;
output_token->length = 0;
output_token->value = NULL;
mech_output_token.length = 0;
mech_output_token.value = NULL;
mech_buf.value = NULL;
mech_buf.length = 0;
ret = decode_NegotiationToken(input_token->value, input_token->length,
&resp, NULL);
if (ret)
return ret;
if (resp.element != choice_NegotiationToken_negTokenResp) {
free_NegotiationToken(&resp);
*minor_status = 0;
return GSS_S_BAD_MECH;
}
if (resp.u.negTokenResp.negResult == NULL
|| *(resp.u.negTokenResp.negResult) == reject
/* || resp.u.negTokenResp.supportedMech == NULL */
)
{
free_NegotiationToken(&resp);
return GSS_S_BAD_MECH;
}
/*
* Pick up the mechanism that the acceptor selected, only allow it
* to be sent in packet.
*/
HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
if (resp.u.negTokenResp.supportedMech) {
if (ctx->oidlen) {
free_NegotiationToken(&resp);
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
return GSS_S_BAD_MECH;
}
ret = der_put_oid(ctx->oidbuf + sizeof(ctx->oidbuf) - 1,
sizeof(ctx->oidbuf),
resp.u.negTokenResp.supportedMech,
&ctx->oidlen);
/* Avoid recursively embedded SPNEGO */
if (ret || (ctx->oidlen == GSS_SPNEGO_MECHANISM->length &&
memcmp(ctx->oidbuf + sizeof(ctx->oidbuf) - ctx->oidlen,
GSS_SPNEGO_MECHANISM->elements,
ctx->oidlen) == 0))
{
free_NegotiationToken(&resp);
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
return GSS_S_BAD_MECH;
}
/* check if the acceptor took our optimistic token */
if (ctx->oidlen != ctx->preferred_mech_type->length ||
memcmp(ctx->oidbuf + sizeof(ctx->oidbuf) - ctx->oidlen,
ctx->preferred_mech_type->elements,
ctx->oidlen) != 0)
{
gss_delete_sec_context(&minor, &ctx->negotiated_ctx_id,
GSS_C_NO_BUFFER);
ctx->negotiated_ctx_id = GSS_C_NO_CONTEXT;
}
} else if (ctx->oidlen == 0) {
free_NegotiationToken(&resp);
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
return GSS_S_BAD_MECH;
}
/* if a token (of non zero length), or no context, pass to underlaying mech */
if ((resp.u.negTokenResp.responseToken != NULL && resp.u.negTokenResp.responseToken->length) ||
ctx->negotiated_ctx_id == GSS_C_NO_CONTEXT) {
gss_buffer_desc mech_input_token;
if (resp.u.negTokenResp.responseToken) {
mech_input_token.length = resp.u.negTokenResp.responseToken->length;
mech_input_token.value = resp.u.negTokenResp.responseToken->data;
} else {
mech_input_token.length = 0;
mech_input_token.value = NULL;
}
mech.length = ctx->oidlen;
mech.elements = ctx->oidbuf + sizeof(ctx->oidbuf) - ctx->oidlen;
/* Fall through as if the negotiated mechanism
was requested explicitly */
ret = gss_init_sec_context(&minor,
cred,
&ctx->negotiated_ctx_id,
ctx->target_name,
&mech,
req_flags,
time_req,
input_chan_bindings,
&mech_input_token,
&ctx->negotiated_mech_type,
&mech_output_token,
&ctx->mech_flags,
&ctx->mech_time_rec);
if (GSS_ERROR(ret)) {
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
free_NegotiationToken(&resp);
gss_mg_collect_error(&mech, ret, minor);
*minor_status = minor;
return ret;
}
if (ret == GSS_S_COMPLETE) {
ctx->open = 1;
}
} else if (*(resp.u.negTokenResp.negResult) == accept_completed) {
if (ctx->maybe_open)
ctx->open = 1;
}
if (*(resp.u.negTokenResp.negResult) == request_mic) {
ctx->require_mic = 1;
}
if (ctx->open) {
/*
* Verify the mechListMIC if one was provided or CFX was
* used and a non-preferred mechanism was selected
*/
if (resp.u.negTokenResp.mechListMIC != NULL) {
require_mic = 1;
} else {
ret = _gss_spnego_require_mechlist_mic(minor_status, ctx,
&require_mic);
if (ret) {
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
free_NegotiationToken(&resp);
gss_release_buffer(&minor, &mech_output_token);
return ret;
}
}
} else {
require_mic = 0;
}
if (require_mic) {
ASN1_MALLOC_ENCODE(MechTypeList, mech_buf.value, mech_buf.length,
&ctx->initiator_mech_types, &buf_len, ret);
if (ret) {
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
free_NegotiationToken(&resp);
gss_release_buffer(&minor, &mech_output_token);
*minor_status = ret;
return GSS_S_FAILURE;
}
if (mech_buf.length != buf_len) {
abort();
UNREACHABLE(return GSS_S_FAILURE);
}
if (resp.u.negTokenResp.mechListMIC == NULL) {
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
free(mech_buf.value);
free_NegotiationToken(&resp);
*minor_status = 0;
return GSS_S_DEFECTIVE_TOKEN;
}
mic_buf.length = resp.u.negTokenResp.mechListMIC->length;
mic_buf.value = resp.u.negTokenResp.mechListMIC->data;
if (mech_output_token.length == 0) {
ret = gss_verify_mic(minor_status,
ctx->negotiated_ctx_id,
&mech_buf,
&mic_buf,
NULL);
if (ret) {
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
free(mech_buf.value);
gss_release_buffer(&minor, &mech_output_token);
free_NegotiationToken(&resp);
return GSS_S_DEFECTIVE_TOKEN;
}
ctx->verified_mic = 1;
}
}
ret = spnego_reply_internal(minor_status, ctx,
require_mic ? &mech_buf : NULL,
&mech_output_token,
output_token);
if (mech_buf.value != NULL)
free(mech_buf.value);
free_NegotiationToken(&resp);
gss_release_buffer(&minor, &mech_output_token);
if (actual_mech_type)
*actual_mech_type = ctx->negotiated_mech_type;
if (ret_flags)
*ret_flags = ctx->mech_flags;
if (time_rec)
*time_rec = ctx->mech_time_rec;
HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
return ret;
}
OM_uint32 GSSAPI_CALLCONV
_gss_spnego_init_sec_context
(OM_uint32 * minor_status,
gss_const_cred_id_t initiator_cred_handle,
gss_ctx_id_t * context_handle,
gss_const_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
)
{
if (*context_handle == GSS_C_NO_CONTEXT)
return spnego_initial (minor_status,
initiator_cred_handle,
context_handle,
target_name,
mech_type,
req_flags,
time_req,
input_chan_bindings,
input_token,
actual_mech_type,
output_token,
ret_flags,
time_rec);
else
return spnego_reply (minor_status,
initiator_cred_handle,
context_handle,
target_name,
mech_type,
req_flags,
time_req,
input_chan_bindings,
input_token,
actual_mech_type,
output_token,
ret_flags,
time_rec);
}