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/*
Unix SMB/CIFS implementation.
SMB Transport encryption (sealing) code.
Copyright (C) Jeremy Allison 2007.
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/******************************************************************************
Generic code for client and server.
Is encryption turned on ?
******************************************************************************/
BOOL common_encryption_on(struct smb_trans_enc_state *es)
{
return ((es != NULL) && es->enc_on);
}
/******************************************************************************
Generic code for client and server.
NTLM decrypt an incoming buffer.
******************************************************************************/
NTSTATUS common_ntlm_decrypt_buffer(NTLMSSP_STATE *ntlmssp_state, char *buf)
{
NTSTATUS status;
size_t orig_len = smb_len(buf);
size_t new_len = orig_len - NTLMSSP_SIG_SIZE;
DATA_BLOB sig;
if (orig_len < 8 + NTLMSSP_SIG_SIZE) {
return NT_STATUS_BUFFER_TOO_SMALL;
}
/* Save off the signature. */
sig = data_blob(buf+orig_len-NTLMSSP_SIG_SIZE, NTLMSSP_SIG_SIZE);
status = ntlmssp_unseal_packet(ntlmssp_state,
(unsigned char *)buf + 8, /* 4 byte len + 0xFF 'S' 'M' 'B' */
new_len - 8,
(unsigned char *)buf,
new_len,
&sig);
if (!NT_STATUS_IS_OK(status)) {
data_blob_free(&sig);
return status;
}
/* Reset the length. */
smb_setlen(buf, new_len);
return NT_STATUS_OK;
}
/******************************************************************************
Generic code for client and server.
NTLM encrypt an outgoing buffer. Return the encrypted pointer in ppbuf_out.
******************************************************************************/
NTSTATUS common_ntlm_encrypt_buffer(NTLMSSP_STATE *ntlmssp_state, char *buf, char **ppbuf_out)
{
NTSTATUS status;
char *buf_out;
size_t orig_len = smb_len(buf);
size_t new_len = orig_len + NTLMSSP_SIG_SIZE;
DATA_BLOB sig;
*ppbuf_out = NULL;
if (orig_len < 8) {
return NT_STATUS_BUFFER_TOO_SMALL;
}
/*
* We know smb_len can't return a value > 128k, so no int overflow
* check needed.
*/
/* Copy the original buffer. */
buf_out = SMB_XMALLOC_ARRAY(char, new_len);
memcpy(buf_out, buf, orig_len);
/* Last 16 bytes undefined here... */
smb_setlen(buf_out, new_len);
sig = data_blob(NULL, NTLMSSP_SIG_SIZE);
status = ntlmssp_seal_packet(ntlmssp_state,
(unsigned char *)buf_out + 8, /* 4 byte len + 0xFF 'S' 'M' 'B' */
orig_len - 8,
(unsigned char *)buf_out,
orig_len,
&sig);
if (!NT_STATUS_IS_OK(status)) {
data_blob_free(&sig);
SAFE_FREE(buf_out);
return status;
}
memcpy(buf_out+orig_len, sig.data, NTLMSSP_SIG_SIZE);
*ppbuf_out = buf_out;
return NT_STATUS_OK;
}
/******************************************************************************
Generic code for client and server.
gss-api decrypt an incoming buffer.
******************************************************************************/
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
NTSTATUS common_gss_decrypt_buffer(gss_ctx_id_t context_handle, char *buf)
{
return NT_STATUS_NOT_SUPPORTED;
}
#endif
/******************************************************************************
Generic code for client and server.
gss-api encrypt an outgoing buffer. Return the alloced encrypted pointer in buf_out.
******************************************************************************/
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
NTSTATUS common_gss_encrypt_buffer(gss_ctx_id_t context_handle, char *buf, char **buf_out)
{
return NT_STATUS_NOT_SUPPORTED;
}
#endif
/******************************************************************************
Generic code for client and server.
Encrypt an outgoing buffer. Return the alloced encrypted pointer in buf_out.
******************************************************************************/
NTSTATUS common_encrypt_buffer(struct smb_trans_enc_state *es, char *buffer, char **buf_out)
{
if (!common_encryption_on(es)) {
/* Not encrypting. */
*buf_out = buffer;
return NT_STATUS_OK;
}
/* Ignore session keepalives. */
if(CVAL(buffer,0) == SMBkeepalive) {
*buf_out = buffer;
return NT_STATUS_OK;
}
if (es->smb_enc_type == SMB_TRANS_ENC_NTLM) {
return common_ntlm_encrypt_buffer(es->ntlmssp_state, buffer, buf_out);
} else {
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
return common_gss_encrypt_buffer(es->context_handle, buffer, buf_out);
#else
return NT_STATUS_NOT_SUPPORTED;
#endif
}
}
/******************************************************************************
Generic code for client and server.
Decrypt an incoming SMB buffer. Replaces the data within it.
New data must be less than or equal to the current length.
******************************************************************************/
NTSTATUS common_decrypt_buffer(struct smb_trans_enc_state *es, char *buf)
{
if (!common_encryption_on(es)) {
/* Not decrypting. */
return NT_STATUS_OK;
}
/* Ignore session keepalives. */
if(CVAL(buf,0) == SMBkeepalive) {
return NT_STATUS_OK;
}
if (es->smb_enc_type == SMB_TRANS_ENC_NTLM) {
return common_ntlm_decrypt_buffer(es->ntlmssp_state, buf);
} else {
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
return common_gss_decrypt_buffer(es->context_handle, buf);
#else
return NT_STATUS_NOT_SUPPORTED;
#endif
}
}
/******************************************************************************
Shutdown an encryption state.
******************************************************************************/
void common_free_encryption_state(struct smb_trans_enc_state **pp_es)
{
struct smb_trans_enc_state *es = *pp_es;
if (es == NULL) {
return;
}
if (es->smb_enc_type == SMB_TRANS_ENC_NTLM) {
if (es->ntlmssp_state) {
ntlmssp_end(&es->ntlmssp_state);
}
}
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
if (es->smb_enc_type == SMB_TRANS_ENC_GSS) {
/* Free the gss context handle. */
}
#endif
SAFE_FREE(es);
*pp_es = NULL;
}
/******************************************************************************
Free an encryption-allocated buffer.
******************************************************************************/
void common_free_enc_buffer(struct smb_trans_enc_state *es, char *buf)
{
if (!common_encryption_on(es)) {
return;
}
if (es->smb_enc_type == SMB_TRANS_ENC_NTLM) {
SAFE_FREE(buf);
return;
}
#if defined(HAVE_GSSAPI_SUPPORT) && defined(HAVE_KRB5)
/* gss-api free buffer.... */
#endif
}
/******************************************************************************
Client side encryption.
******************************************************************************/
/******************************************************************************
Is client encryption on ?
******************************************************************************/
BOOL cli_encryption_on(struct cli_state *cli)
{
return common_encryption_on(cli->trans_enc_state);
}
/******************************************************************************
Shutdown a client encryption state.
******************************************************************************/
void cli_free_encryption_context(struct cli_state *cli)
{
return common_free_encryption_state(&cli->trans_enc_state);
}
/******************************************************************************
Free an encryption-allocated buffer.
******************************************************************************/
void cli_free_enc_buffer(struct cli_state *cli, char *buf)
{
return common_free_enc_buffer(cli->trans_enc_state, buf);
}
/******************************************************************************
Decrypt an incoming buffer.
******************************************************************************/
NTSTATUS cli_decrypt_message(struct cli_state *cli)
{
return common_decrypt_buffer(cli->trans_enc_state, cli->inbuf);
}
/******************************************************************************
Encrypt an outgoing buffer. Return the encrypted pointer in buf_out.
******************************************************************************/
NTSTATUS cli_encrypt_message(struct cli_state *cli, char **buf_out)
{
return common_encrypt_buffer(cli->trans_enc_state, cli->outbuf, buf_out);
}
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