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samba-mirror/source3/smbd/smb2_negprot.c
Volker Lendecke dea1881fc5 smbd: Remove an indentation level in smb2_negprot
Do an early return. Best viewed with "git show -b"

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2017-10-27 20:33:25 +02:00

705 lines
19 KiB
C

/*
Unix SMB/CIFS implementation.
Core SMB2 server
Copyright (C) Stefan Metzmacher 2009
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 "smbd/smbd.h"
#include "smbd/globals.h"
#include "../libcli/smb/smb_common.h"
#include "../libcli/smb/smb2_negotiate_context.h"
#include "../lib/tsocket/tsocket.h"
#include "../librpc/ndr/libndr.h"
#include "../libcli/smb/smb_signing.h"
extern fstring remote_proto;
/*
* this is the entry point if SMB2 is selected via
* the SMB negprot and the given dialect.
*/
static void reply_smb20xx(struct smb_request *req, uint16_t dialect)
{
uint8_t *smb2_inpdu;
uint8_t *smb2_hdr;
uint8_t *smb2_body;
uint8_t *smb2_dyn;
size_t len = SMB2_HDR_BODY + 0x24 + 2;
smb2_inpdu = talloc_zero_array(talloc_tos(), uint8_t, len);
if (smb2_inpdu == NULL) {
DEBUG(0, ("Could not push spnego blob\n"));
reply_nterror(req, NT_STATUS_NO_MEMORY);
return;
}
smb2_hdr = smb2_inpdu;
smb2_body = smb2_hdr + SMB2_HDR_BODY;
smb2_dyn = smb2_body + 0x24;
SIVAL(smb2_hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
SIVAL(smb2_hdr, SMB2_HDR_LENGTH, SMB2_HDR_BODY);
SSVAL(smb2_body, 0x00, 0x0024); /* struct size */
SSVAL(smb2_body, 0x02, 0x0001); /* dialect count */
SSVAL(smb2_dyn, 0x00, dialect);
req->outbuf = NULL;
smbd_smb2_process_negprot(req->xconn, 0, smb2_inpdu, len);
return;
}
/*
* this is the entry point if SMB2 is selected via
* the SMB negprot and the "SMB 2.002" dialect.
*/
void reply_smb2002(struct smb_request *req, uint16_t choice)
{
reply_smb20xx(req, SMB2_DIALECT_REVISION_202);
}
/*
* this is the entry point if SMB2 is selected via
* the SMB negprot and the "SMB 2.???" dialect.
*/
void reply_smb20ff(struct smb_request *req, uint16_t choice)
{
struct smbXsrv_connection *xconn = req->xconn;
xconn->smb2.allow_2ff = true;
reply_smb20xx(req, SMB2_DIALECT_REVISION_2FF);
}
enum protocol_types smbd_smb2_protocol_dialect_match(const uint8_t *indyn,
const int dialect_count,
uint16_t *dialect)
{
struct {
enum protocol_types proto;
uint16_t dialect;
} pd[] = {
{ PROTOCOL_SMB3_11, SMB3_DIALECT_REVISION_311 },
{ PROTOCOL_SMB3_10, SMB3_DIALECT_REVISION_310 },
{ PROTOCOL_SMB3_02, SMB3_DIALECT_REVISION_302 },
{ PROTOCOL_SMB3_00, SMB3_DIALECT_REVISION_300 },
{ PROTOCOL_SMB2_24, SMB2_DIALECT_REVISION_224 },
{ PROTOCOL_SMB2_22, SMB2_DIALECT_REVISION_222 },
{ PROTOCOL_SMB2_10, SMB2_DIALECT_REVISION_210 },
{ PROTOCOL_SMB2_02, SMB2_DIALECT_REVISION_202 },
};
size_t i;
for (i = 0; i < ARRAY_SIZE(pd); i ++) {
size_t c = 0;
if (lp_server_max_protocol() < pd[i].proto) {
continue;
}
if (lp_server_min_protocol() > pd[i].proto) {
continue;
}
for (c = 0; c < dialect_count; c++) {
*dialect = SVAL(indyn, c*2);
if (*dialect == pd[i].dialect) {
return pd[i].proto;
}
}
}
return PROTOCOL_NONE;
}
NTSTATUS smbd_smb2_request_process_negprot(struct smbd_smb2_request *req)
{
struct smbXsrv_connection *xconn = req->xconn;
struct smbXsrv_client_global0 *global0 = NULL;
NTSTATUS status;
const uint8_t *inbody;
const uint8_t *indyn = NULL;
DATA_BLOB outbody;
DATA_BLOB outdyn;
DATA_BLOB negprot_spnego_blob;
uint16_t security_offset;
DATA_BLOB security_buffer;
size_t expected_dyn_size = 0;
size_t c;
uint16_t security_mode;
uint16_t dialect_count;
uint16_t in_security_mode;
uint32_t in_capabilities;
DATA_BLOB in_guid_blob;
struct GUID in_guid;
struct smb2_negotiate_contexts in_c = { .num_contexts = 0, };
struct smb2_negotiate_context *in_preauth = NULL;
struct smb2_negotiate_context *in_cipher = NULL;
struct smb2_negotiate_contexts out_c = { .num_contexts = 0, };
DATA_BLOB out_negotiate_context_blob = data_blob_null;
uint32_t out_negotiate_context_offset = 0;
uint16_t out_negotiate_context_count = 0;
uint16_t dialect = 0;
uint32_t capabilities;
DATA_BLOB out_guid_blob;
struct GUID out_guid;
enum protocol_types protocol = PROTOCOL_NONE;
uint32_t max_limit;
uint32_t max_trans = lp_smb2_max_trans();
uint32_t max_read = lp_smb2_max_read();
uint32_t max_write = lp_smb2_max_write();
NTTIME now = timeval_to_nttime(&req->request_time);
bool signing_required = true;
bool ok;
status = smbd_smb2_request_verify_sizes(req, 0x24);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
inbody = SMBD_SMB2_IN_BODY_PTR(req);
dialect_count = SVAL(inbody, 0x02);
in_security_mode = SVAL(inbody, 0x04);
in_capabilities = IVAL(inbody, 0x08);
in_guid_blob = data_blob_const(inbody + 0x0C, 16);
if (dialect_count == 0) {
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
expected_dyn_size = dialect_count * 2;
if (SMBD_SMB2_IN_DYN_LEN(req) < expected_dyn_size) {
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
indyn = SMBD_SMB2_IN_DYN_PTR(req);
protocol = smbd_smb2_protocol_dialect_match(indyn,
dialect_count,
&dialect);
for (c=0; protocol == PROTOCOL_NONE && c < dialect_count; c++) {
if (lp_server_max_protocol() < PROTOCOL_SMB2_10) {
break;
}
dialect = SVAL(indyn, c*2);
if (dialect == SMB2_DIALECT_REVISION_2FF) {
if (xconn->smb2.allow_2ff) {
xconn->smb2.allow_2ff = false;
protocol = PROTOCOL_SMB2_10;
break;
}
}
}
if (protocol == PROTOCOL_NONE) {
return smbd_smb2_request_error(req, NT_STATUS_NOT_SUPPORTED);
}
if (protocol >= PROTOCOL_SMB3_10) {
uint32_t in_negotiate_context_offset = 0;
uint16_t in_negotiate_context_count = 0;
DATA_BLOB in_negotiate_context_blob = data_blob_null;
size_t ofs;
in_negotiate_context_offset = IVAL(inbody, 0x1C);
in_negotiate_context_count = SVAL(inbody, 0x20);
ofs = SMB2_HDR_BODY;
ofs += SMBD_SMB2_IN_BODY_LEN(req);
ofs += expected_dyn_size;
if ((ofs % 8) != 0) {
ofs += 8 - (ofs % 8);
}
if (in_negotiate_context_offset != ofs) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
ofs -= SMB2_HDR_BODY;
ofs -= SMBD_SMB2_IN_BODY_LEN(req);
if (SMBD_SMB2_IN_DYN_LEN(req) < ofs) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
in_negotiate_context_blob = data_blob_const(indyn,
SMBD_SMB2_IN_DYN_LEN(req));
in_negotiate_context_blob.data += ofs;
in_negotiate_context_blob.length -= ofs;
status = smb2_negotiate_context_parse(req,
in_negotiate_context_blob, &in_c);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
if (in_negotiate_context_count != in_c.num_contexts) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
}
if ((dialect != SMB2_DIALECT_REVISION_2FF) &&
(protocol >= PROTOCOL_SMB2_10) &&
!GUID_all_zero(&in_guid))
{
ok = remote_arch_cache_update(&in_guid);
if (!ok) {
return smbd_smb2_request_error(
req, NT_STATUS_UNSUCCESSFUL);
}
}
switch (get_remote_arch()) {
case RA_VISTA:
case RA_SAMBA:
case RA_CIFSFS:
case RA_OSX:
break;
default:
set_remote_arch(RA_VISTA);
break;
}
fstr_sprintf(remote_proto, "SMB%X_%02X",
(dialect >> 8) & 0xFF, dialect & 0xFF);
reload_services(req->sconn, conn_snum_used, true);
DEBUG(3,("Selected protocol %s\n", remote_proto));
in_preauth = smb2_negotiate_context_find(&in_c,
SMB2_PREAUTH_INTEGRITY_CAPABILITIES);
if (protocol >= PROTOCOL_SMB3_10 && in_preauth == NULL) {
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
in_cipher = smb2_negotiate_context_find(&in_c,
SMB2_ENCRYPTION_CAPABILITIES);
/* negprot_spnego() returns a the server guid in the first 16 bytes */
negprot_spnego_blob = negprot_spnego(req, xconn);
if (negprot_spnego_blob.data == NULL) {
return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
}
if (negprot_spnego_blob.length < 16) {
return smbd_smb2_request_error(req, NT_STATUS_INTERNAL_ERROR);
}
security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
/*
* We use xconn->smb1.signing_state as that's already present
* and used lpcfg_server_signing_allowed() to get the correct
* defaults, e.g. signing_required for an ad_dc.
*/
signing_required = smb_signing_is_mandatory(xconn->smb1.signing_state);
if (signing_required) {
security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
}
capabilities = 0;
if (lp_host_msdfs()) {
capabilities |= SMB2_CAP_DFS;
}
if (protocol >= PROTOCOL_SMB2_10 &&
lp_smb2_leases() &&
lp_oplocks(GLOBAL_SECTION_SNUM) &&
!lp_kernel_oplocks(GLOBAL_SECTION_SNUM))
{
capabilities |= SMB2_CAP_LEASING;
}
if ((protocol >= PROTOCOL_SMB2_24) &&
(lp_smb_encrypt(-1) != SMB_SIGNING_OFF) &&
(in_capabilities & SMB2_CAP_ENCRYPTION)) {
capabilities |= SMB2_CAP_ENCRYPTION;
}
/*
* 0x10000 (65536) is the maximum allowed message size
* for SMB 2.0
*/
max_limit = 0x10000;
if (protocol >= PROTOCOL_SMB2_10) {
int p = 0;
if (tsocket_address_is_inet(req->sconn->local_address, "ip")) {
p = tsocket_address_inet_port(req->sconn->local_address);
}
/* largeMTU is not supported over NBT (tcp port 139) */
if (p != NBT_SMB_PORT) {
capabilities |= SMB2_CAP_LARGE_MTU;
xconn->smb2.credits.multicredit = true;
/*
* We allow up to almost 16MB.
*
* The maximum PDU size is 0xFFFFFF (16776960)
* and we need some space for the header.
*/
max_limit = 0xFFFF00;
}
}
/*
* the defaults are 8MB, but we'll limit this to max_limit based on
* the dialect (64kb for SMB 2.0, 8MB for SMB >= 2.1 with LargeMTU)
*
* user configured values exceeding the limits will be overwritten,
* only smaller values will be accepted
*/
max_trans = MIN(max_limit, lp_smb2_max_trans());
max_read = MIN(max_limit, lp_smb2_max_read());
max_write = MIN(max_limit, lp_smb2_max_write());
if (in_preauth != NULL) {
size_t needed = 4;
uint16_t hash_count;
uint16_t salt_length;
uint16_t selected_preauth = 0;
const uint8_t *p;
uint8_t buf[38];
DATA_BLOB b;
size_t i;
if (in_preauth->data.length < needed) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
hash_count = SVAL(in_preauth->data.data, 0);
salt_length = SVAL(in_preauth->data.data, 2);
if (hash_count == 0) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
p = in_preauth->data.data + needed;
needed += hash_count * 2;
needed += salt_length;
if (in_preauth->data.length < needed) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
for (i=0; i < hash_count; i++) {
uint16_t v;
v = SVAL(p, 0);
p += 2;
if (v == SMB2_PREAUTH_INTEGRITY_SHA512) {
selected_preauth = v;
break;
}
}
if (selected_preauth == 0) {
return smbd_smb2_request_error(req,
NT_STATUS_SMB_NO_PREAUTH_INTEGRITY_HASH_OVERLAP);
}
SSVAL(buf, 0, 1); /* HashAlgorithmCount */
SSVAL(buf, 2, 32); /* SaltLength */
SSVAL(buf, 4, selected_preauth);
generate_random_buffer(buf + 6, 32);
b = data_blob_const(buf, sizeof(buf));
status = smb2_negotiate_context_add(req, &out_c,
SMB2_PREAUTH_INTEGRITY_CAPABILITIES, b);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
req->preauth = &req->xconn->smb2.preauth;
}
if ((capabilities & SMB2_CAP_ENCRYPTION) && (in_cipher != NULL)) {
size_t needed = 2;
uint16_t cipher_count;
const uint8_t *p;
uint8_t buf[4];
DATA_BLOB b;
size_t i;
bool aes_128_ccm_supported = false;
bool aes_128_gcm_supported = false;
capabilities &= ~SMB2_CAP_ENCRYPTION;
if (in_cipher->data.length < needed) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
cipher_count = SVAL(in_cipher->data.data, 0);
if (cipher_count == 0) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
p = in_cipher->data.data + needed;
needed += cipher_count * 2;
if (in_cipher->data.length < needed) {
return smbd_smb2_request_error(req,
NT_STATUS_INVALID_PARAMETER);
}
for (i=0; i < cipher_count; i++) {
uint16_t v;
v = SVAL(p, 0);
p += 2;
if (v == SMB2_ENCRYPTION_AES128_GCM) {
aes_128_gcm_supported = true;
}
if (v == SMB2_ENCRYPTION_AES128_CCM) {
aes_128_ccm_supported = true;
}
}
/*
* For now we preferr CCM because our implementation
* is faster than GCM, see bug #11451.
*/
if (aes_128_ccm_supported) {
xconn->smb2.server.cipher = SMB2_ENCRYPTION_AES128_CCM;
} else if (aes_128_gcm_supported) {
xconn->smb2.server.cipher = SMB2_ENCRYPTION_AES128_GCM;
}
SSVAL(buf, 0, 1); /* ChiperCount */
SSVAL(buf, 2, xconn->smb2.server.cipher);
b = data_blob_const(buf, sizeof(buf));
status = smb2_negotiate_context_add(req, &out_c,
SMB2_ENCRYPTION_CAPABILITIES, b);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
}
if (capabilities & SMB2_CAP_ENCRYPTION) {
xconn->smb2.server.cipher = SMB2_ENCRYPTION_AES128_CCM;
}
if (protocol >= PROTOCOL_SMB2_22 &&
xconn->client->server_multi_channel_enabled)
{
if (in_capabilities & SMB2_CAP_MULTI_CHANNEL) {
capabilities |= SMB2_CAP_MULTI_CHANNEL;
}
}
security_offset = SMB2_HDR_BODY + 0x40;
#if 1
/* Try SPNEGO auth... */
security_buffer = data_blob_const(negprot_spnego_blob.data + 16,
negprot_spnego_blob.length - 16);
#else
/* for now we want raw NTLMSSP */
security_buffer = data_blob_const(NULL, 0);
#endif
if (out_c.num_contexts != 0) {
status = smb2_negotiate_context_push(req,
&out_negotiate_context_blob,
out_c);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
}
if (out_negotiate_context_blob.length != 0) {
static const uint8_t zeros[8];
size_t pad = 0;
size_t ofs;
outdyn = data_blob_dup_talloc(req, security_buffer);
if (outdyn.length != security_buffer.length) {
return smbd_smb2_request_error(req,
NT_STATUS_NO_MEMORY);
}
ofs = security_offset + security_buffer.length;
if ((ofs % 8) != 0) {
pad = 8 - (ofs % 8);
}
ofs += pad;
ok = data_blob_append(req, &outdyn, zeros, pad);
if (!ok) {
return smbd_smb2_request_error(req,
NT_STATUS_NO_MEMORY);
}
ok = data_blob_append(req, &outdyn,
out_negotiate_context_blob.data,
out_negotiate_context_blob.length);
if (!ok) {
return smbd_smb2_request_error(req,
NT_STATUS_NO_MEMORY);
}
out_negotiate_context_offset = ofs;
out_negotiate_context_count = out_c.num_contexts;
} else {
outdyn = security_buffer;
}
out_guid_blob = data_blob_const(negprot_spnego_blob.data, 16);
status = GUID_from_ndr_blob(&out_guid_blob, &out_guid);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
outbody = smbd_smb2_generate_outbody(req, 0x40);
if (outbody.data == NULL) {
return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
}
SSVAL(outbody.data, 0x00, 0x40 + 1); /* struct size */
SSVAL(outbody.data, 0x02,
security_mode); /* security mode */
SSVAL(outbody.data, 0x04, dialect); /* dialect revision */
SSVAL(outbody.data, 0x06,
out_negotiate_context_count); /* reserved/NegotiateContextCount */
memcpy(outbody.data + 0x08,
out_guid_blob.data, 16); /* server guid */
SIVAL(outbody.data, 0x18,
capabilities); /* capabilities */
SIVAL(outbody.data, 0x1C, max_trans); /* max transact size */
SIVAL(outbody.data, 0x20, max_read); /* max read size */
SIVAL(outbody.data, 0x24, max_write); /* max write size */
SBVAL(outbody.data, 0x28, now); /* system time */
SBVAL(outbody.data, 0x30, 0); /* server start time */
SSVAL(outbody.data, 0x38,
security_offset); /* security buffer offset */
SSVAL(outbody.data, 0x3A,
security_buffer.length); /* security buffer length */
SIVAL(outbody.data, 0x3C,
out_negotiate_context_offset); /* reserved/NegotiateContextOffset */
req->sconn->using_smb2 = true;
if (dialect == SMB2_DIALECT_REVISION_2FF) {
return smbd_smb2_request_done(req, outbody, &outdyn);
}
status = smbXsrv_connection_init_tables(xconn, protocol);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
xconn->smb2.client.capabilities = in_capabilities;
xconn->smb2.client.security_mode = in_security_mode;
xconn->smb2.client.guid = in_guid;
xconn->smb2.client.num_dialects = dialect_count;
xconn->smb2.client.dialects = talloc_array(xconn,
uint16_t,
dialect_count);
if (xconn->smb2.client.dialects == NULL) {
return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
}
for (c=0; c < dialect_count; c++) {
xconn->smb2.client.dialects[c] = SVAL(indyn, c*2);
}
xconn->smb2.server.capabilities = capabilities;
xconn->smb2.server.security_mode = security_mode;
xconn->smb2.server.guid = out_guid;
xconn->smb2.server.dialect = dialect;
xconn->smb2.server.max_trans = max_trans;
xconn->smb2.server.max_read = max_read;
xconn->smb2.server.max_write = max_write;
if (xconn->protocol < PROTOCOL_SMB2_10) {
/*
* SMB2_02 doesn't support client guids
*/
return smbd_smb2_request_done(req, outbody, &outdyn);
}
if (!xconn->client->server_multi_channel_enabled) {
/*
* Only deal with the client guid database
* if multi-channel is enabled.
*/
return smbd_smb2_request_done(req, outbody, &outdyn);
}
if (xconn->smb2.client.guid_verified) {
/*
* The connection was passed from another
* smbd process.
*/
return smbd_smb2_request_done(req, outbody, &outdyn);
}
status = smb2srv_client_lookup_global(xconn->client,
xconn->smb2.client.guid,
req, &global0);
/*
* TODO: check for races...
*/
if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECTID_NOT_FOUND)) {
/*
* This stores the new client information in
* smbXsrv_client_global.tdb
*/
xconn->client->global->client_guid =
xconn->smb2.client.guid;
status = smbXsrv_client_update(xconn->client);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
xconn->smb2.client.guid_verified = true;
} else if (NT_STATUS_IS_OK(status)) {
status = smb2srv_client_connection_pass(req,
global0);
if (!NT_STATUS_IS_OK(status)) {
return smbd_smb2_request_error(req, status);
}
smbd_server_connection_terminate(xconn,
"passed connection");
return NT_STATUS_OBJECTID_EXISTS;
} else {
return smbd_smb2_request_error(req, status);
}
return smbd_smb2_request_done(req, outbody, &outdyn);
}