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/*
Unix SMB/CIFS implementation.
RFC2478 Compliant SPNEGO implementation
Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
This program 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.
This program 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 <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "auth/gensec/spnego.h"
#include "auth/gensec/gensec.h"
#include "libcli/util/asn_1.h"
static BOOL read_negTokenInit(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
struct spnego_negTokenInit *token)
{
ZERO_STRUCTP(token);
asn1_start_tag(asn1, ASN1_CONTEXT(0));
asn1_start_tag(asn1, ASN1_SEQUENCE(0));
while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
int i;
uint8_t context;
if (!asn1_peek_uint8(asn1, &context)) {
asn1->has_error = True;
break;
}
switch (context) {
/* Read mechTypes */
case ASN1_CONTEXT(0):
asn1_start_tag(asn1, ASN1_CONTEXT(0));
asn1_start_tag(asn1, ASN1_SEQUENCE(0));
token->mechTypes = talloc(NULL, const char *);
for (i = 0; !asn1->has_error &&
0 < asn1_tag_remaining(asn1); i++) {
token->mechTypes = talloc_realloc(NULL,
token->mechTypes,
const char *, i+2);
asn1_read_OID(asn1, token->mechTypes, token->mechTypes + i);
}
token->mechTypes[i] = NULL;
asn1_end_tag(asn1);
asn1_end_tag(asn1);
break;
/* Read reqFlags */
case ASN1_CONTEXT(1):
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_read_Integer(asn1, &token->reqFlags);
token->reqFlags |= SPNEGO_REQ_FLAG;
asn1_end_tag(asn1);
break;
/* Read mechToken */
case ASN1_CONTEXT(2):
asn1_start_tag(asn1, ASN1_CONTEXT(2));
asn1_read_OctetString(asn1, mem_ctx, &token->mechToken);
asn1_end_tag(asn1);
break;
/* Read mecListMIC */
case ASN1_CONTEXT(3):
{
uint8_t type_peek;
asn1_start_tag(asn1, ASN1_CONTEXT(3));
if (!asn1_peek_uint8(asn1, &type_peek)) {
asn1->has_error = True;
break;
}
if (type_peek == ASN1_OCTET_STRING) {
asn1_read_OctetString(asn1, mem_ctx,
&token->mechListMIC);
} else {
/* RFC 2478 says we have an Octet String here,
but W2k sends something different... */
char *mechListMIC;
asn1_push_tag(asn1, ASN1_SEQUENCE(0));
asn1_push_tag(asn1, ASN1_CONTEXT(0));
asn1_read_GeneralString(asn1, mem_ctx, &mechListMIC);
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
token->targetPrincipal = mechListMIC;
}
asn1_end_tag(asn1);
break;
}
default:
asn1->has_error = True;
break;
}
}
asn1_end_tag(asn1);
asn1_end_tag(asn1);
return !asn1->has_error;
}
static BOOL write_negTokenInit(struct asn1_data *asn1, struct spnego_negTokenInit *token)
{
asn1_push_tag(asn1, ASN1_CONTEXT(0));
asn1_push_tag(asn1, ASN1_SEQUENCE(0));
/* Write mechTypes */
if (token->mechTypes && *token->mechTypes) {
int i;
asn1_push_tag(asn1, ASN1_CONTEXT(0));
asn1_push_tag(asn1, ASN1_SEQUENCE(0));
for (i = 0; token->mechTypes[i]; i++) {
asn1_write_OID(asn1, token->mechTypes[i]);
}
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
}
/* write reqFlags */
if (token->reqFlags & SPNEGO_REQ_FLAG) {
int flags = token->reqFlags & ~SPNEGO_REQ_FLAG;
asn1_push_tag(asn1, ASN1_CONTEXT(1));
asn1_write_Integer(asn1, flags);
asn1_pop_tag(asn1);
}
/* write mechToken */
if (token->mechToken.data) {
asn1_push_tag(asn1, ASN1_CONTEXT(2));
asn1_write_OctetString(asn1, token->mechToken.data,
token->mechToken.length);
asn1_pop_tag(asn1);
}
/* write mechListMIC */
if (token->mechListMIC.data) {
asn1_push_tag(asn1, ASN1_CONTEXT(3));
#if 0
/* This is what RFC 2478 says ... */
asn1_write_OctetString(asn1, token->mechListMIC.data,
token->mechListMIC.length);
#else
/* ... but unfortunately this is what Windows
sends/expects */
asn1_push_tag(asn1, ASN1_SEQUENCE(0));
asn1_push_tag(asn1, ASN1_CONTEXT(0));
asn1_push_tag(asn1, ASN1_GENERAL_STRING);
asn1_write(asn1, token->mechListMIC.data,
token->mechListMIC.length);
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
#endif
asn1_pop_tag(asn1);
}
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
return !asn1->has_error;
}
static BOOL read_negTokenTarg(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
struct spnego_negTokenTarg *token)
{
ZERO_STRUCTP(token);
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_start_tag(asn1, ASN1_SEQUENCE(0));
while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
uint8_t context;
if (!asn1_peek_uint8(asn1, &context)) {
asn1->has_error = True;
break;
}
switch (context) {
case ASN1_CONTEXT(0):
asn1_start_tag(asn1, ASN1_CONTEXT(0));
asn1_start_tag(asn1, ASN1_ENUMERATED);
asn1_read_uint8(asn1, &token->negResult);
asn1_end_tag(asn1);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(1):
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_read_OID(asn1, mem_ctx, &token->supportedMech);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(2):
asn1_start_tag(asn1, ASN1_CONTEXT(2));
asn1_read_OctetString(asn1, mem_ctx, &token->responseToken);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(3):
asn1_start_tag(asn1, ASN1_CONTEXT(3));
asn1_read_OctetString(asn1, mem_ctx, &token->mechListMIC);
asn1_end_tag(asn1);
break;
default:
asn1->has_error = True;
break;
}
}
asn1_end_tag(asn1);
asn1_end_tag(asn1);
return !asn1->has_error;
}
static BOOL write_negTokenTarg(struct asn1_data *asn1, struct spnego_negTokenTarg *token)
{
asn1_push_tag(asn1, ASN1_CONTEXT(1));
asn1_push_tag(asn1, ASN1_SEQUENCE(0));
if (token->negResult != SPNEGO_NONE_RESULT) {
asn1_push_tag(asn1, ASN1_CONTEXT(0));
asn1_write_enumerated(asn1, token->negResult);
asn1_pop_tag(asn1);
}
if (token->supportedMech) {
asn1_push_tag(asn1, ASN1_CONTEXT(1));
asn1_write_OID(asn1, token->supportedMech);
asn1_pop_tag(asn1);
}
if (token->responseToken.data) {
asn1_push_tag(asn1, ASN1_CONTEXT(2));
asn1_write_OctetString(asn1, token->responseToken.data,
token->responseToken.length);
asn1_pop_tag(asn1);
}
if (token->mechListMIC.data) {
asn1_push_tag(asn1, ASN1_CONTEXT(3));
asn1_write_OctetString(asn1, token->mechListMIC.data,
token->mechListMIC.length);
asn1_pop_tag(asn1);
}
asn1_pop_tag(asn1);
asn1_pop_tag(asn1);
return !asn1->has_error;
}
ssize_t spnego_read_data(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct spnego_data *token)
{
struct asn1_data *asn1;
ssize_t ret = -1;
uint8_t context;
ZERO_STRUCTP(token);
if (data.length == 0) {
return ret;
}
asn1 = asn1_init(mem_ctx);
if (asn1 == NULL) {
return -1;
}
asn1_load(asn1, data);
if (!asn1_peek_uint8(asn1, &context)) {
asn1->has_error = True;
} else {
switch (context) {
case ASN1_APPLICATION(0):
asn1_start_tag(asn1, ASN1_APPLICATION(0));
asn1_check_OID(asn1, GENSEC_OID_SPNEGO);
if (read_negTokenInit(asn1, mem_ctx, &token->negTokenInit)) {
token->type = SPNEGO_NEG_TOKEN_INIT;
}
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(1):
if (read_negTokenTarg(asn1, mem_ctx, &token->negTokenTarg)) {
token->type = SPNEGO_NEG_TOKEN_TARG;
}
break;
default:
asn1->has_error = True;
break;
}
}
if (!asn1->has_error) ret = asn1->ofs;
asn1_free(asn1);
return ret;
}
ssize_t spnego_write_data(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, struct spnego_data *spnego)
{
struct asn1_data *asn1 = asn1_init(mem_ctx);
ssize_t ret = -1;
if (asn1 == NULL) {
return -1;
}
switch (spnego->type) {
case SPNEGO_NEG_TOKEN_INIT:
asn1_push_tag(asn1, ASN1_APPLICATION(0));
asn1_write_OID(asn1, GENSEC_OID_SPNEGO);
write_negTokenInit(asn1, &spnego->negTokenInit);
asn1_pop_tag(asn1);
break;
case SPNEGO_NEG_TOKEN_TARG:
write_negTokenTarg(asn1, &spnego->negTokenTarg);
break;
default:
asn1->has_error = True;
break;
}
if (!asn1->has_error) {
*blob = data_blob_talloc(mem_ctx, asn1->data, asn1->length);
ret = asn1->ofs;
}
asn1_free(asn1);
return ret;
}
BOOL spnego_free_data(struct spnego_data *spnego)
{
BOOL ret = True;
if (!spnego) goto out;
switch(spnego->type) {
case SPNEGO_NEG_TOKEN_INIT:
if (spnego->negTokenInit.mechTypes) {
talloc_free(spnego->negTokenInit.mechTypes);
}
data_blob_free(&spnego->negTokenInit.mechToken);
data_blob_free(&spnego->negTokenInit.mechListMIC);
talloc_free(spnego->negTokenInit.targetPrincipal);
break;
case SPNEGO_NEG_TOKEN_TARG:
if (spnego->negTokenTarg.supportedMech) {
talloc_free(discard_const(spnego->negTokenTarg.supportedMech));
}
data_blob_free(&spnego->negTokenTarg.responseToken);
data_blob_free(&spnego->negTokenTarg.mechListMIC);
break;
default:
ret = False;
break;
}
ZERO_STRUCTP(spnego);
out:
return ret;
}
|
