first public release of samba4 code

(This used to be commit b0510b5428b3461aeb9bbe3cc95f62fc73e2b97f)

1 files changed, 341 insertions, 0 deletions

diff --git a/source4/libcli/raw/smb_signing.c b/source4/libcli/raw/smb_signing.c
new file mode 100644
index 00000000000..2ab61aa001e
--- /dev/null
+++ b/source4/libcli/raw/smb_signing.c
@@ -0,0 +1,341 @@
+/* 
+   Unix SMB/CIFS implementation.
+   SMB Signing Code
+   Copyright (C) Jeremy Allison 2002.
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
+   Copyright (C) James J Myers <myersjj@samba.org> 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 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"
+
+struct smb_basic_signing_context {
+	DATA_BLOB mac_key;
+	uint32 next_seq_num;
+};
+
+/***********************************************************
+ SMB signing - Common code before we set a new signing implementation
+************************************************************/
+static BOOL set_smb_signing_common(struct cli_transport *transport)
+{
+	if (!(transport->negotiate.sec_mode & 
+	      (NEGOTIATE_SECURITY_SIGNATURES_REQUIRED|NEGOTIATE_SECURITY_SIGNATURES_ENABLED))) {
+		return False;
+	}
+
+	if (transport->negotiate.sign_info.doing_signing) {
+		return False;
+	}
+	
+	if (transport->negotiate.sign_info.free_signing_context)
+		transport->negotiate.sign_info.free_signing_context(transport);
+
+	/* These calls are INCOMPATIBLE with SMB signing */
+	transport->negotiate.readbraw_supported = False;
+	transport->negotiate.writebraw_supported = False;
+	
+	return True;
+}
+
+/***********************************************************
+ SMB signing - Common code for 'real' implementations
+************************************************************/
+static BOOL set_smb_signing_real_common(struct cli_transport *transport) 
+{
+	if (transport->negotiate.sec_mode & NEGOTIATE_SECURITY_SIGNATURES_REQUIRED) {
+		DEBUG(5, ("Mandatory SMB signing enabled!\n"));
+		transport->negotiate.sign_info.doing_signing = True;
+	}
+
+	DEBUG(5, ("SMB signing enabled!\n"));
+
+	return True;
+}
+
+static void mark_packet_signed(struct cli_request *req) 
+{
+	uint16 flags2;
+	flags2 = SVAL(req->out.hdr, HDR_FLG2);
+	flags2 |= FLAGS2_SMB_SECURITY_SIGNATURES;
+	SSVAL(req->out.hdr, HDR_FLG2, flags2);
+}
+
+static BOOL signing_good(struct cli_request *req, BOOL good) 
+{
+	if (good && !req->transport->negotiate.sign_info.doing_signing) {
+		req->transport->negotiate.sign_info.doing_signing = True;
+	}
+
+	if (!good) {
+		if (req->transport->negotiate.sign_info.doing_signing) {
+			DEBUG(1, ("SMB signature check failed!\n"));
+			return False;
+		} else {
+			DEBUG(3, ("Server did not sign reply correctly\n"));
+			cli_transport_free_signing_context(req->transport);
+			return False;
+		}
+	}
+	return True;
+}	
+
+/***********************************************************
+ SMB signing - Simple implementation - calculate a MAC to send.
+************************************************************/
+static void cli_request_simple_sign_outgoing_message(struct cli_request *req)
+{
+	unsigned char calc_md5_mac[16];
+	struct MD5Context md5_ctx;
+	struct smb_basic_signing_context *data = req->transport->negotiate.sign_info.signing_context;
+
+#if 0
+	/* enable this when packet signing is preventing you working out why valgrind 
+	   says that data is uninitialised */
+	file_save("pkt.dat", req->out.buffer, req->out.size);
+#endif
+
+	req->seq_num = data->next_seq_num;
+	
+	/* some requests (eg. NTcancel) are one way, and the sequence number
+	   should be increased by 1 not 2 */
+	if (req->one_way_request) {
+		data->next_seq_num += 1;
+	} else {
+		data->next_seq_num += 2;
+	}
+
+	/*
+	 * Firstly put the sequence number into the first 4 bytes.
+	 * and zero out the next 4 bytes.
+	 */
+	SIVAL(req->out.hdr, HDR_SS_FIELD, req->seq_num);
+	SIVAL(req->out.hdr, HDR_SS_FIELD + 4, 0);
+
+	/* mark the packet as signed - BEFORE we sign it...*/
+	mark_packet_signed(req);
+
+	/* Calculate the 16 byte MAC and place first 8 bytes into the field. */
+	MD5Init(&md5_ctx);
+	MD5Update(&md5_ctx, data->mac_key.data, 
+		  data->mac_key.length); 
+	MD5Update(&md5_ctx, 
+		  req->out.buffer + NBT_HDR_SIZE, 
+		  req->out.size - NBT_HDR_SIZE);
+	MD5Final(calc_md5_mac, &md5_ctx);
+
+	memcpy(&req->out.hdr[HDR_SS_FIELD], calc_md5_mac, 8);
+
+/*	req->out.hdr[HDR_SS_FIELD+2]=0; 
+	Uncomment this to test if the remote server actually verifies signitures...*/
+}
+
+
+/***********************************************************
+ SMB signing - Simple implementation - check a MAC sent by server.
+************************************************************/
+static BOOL cli_request_simple_check_incoming_message(struct cli_request *req)
+{
+	BOOL good;
+	unsigned char calc_md5_mac[16];
+	unsigned char server_sent_mac[8];
+	unsigned char sequence_buf[8];
+	struct MD5Context md5_ctx;
+	struct smb_basic_signing_context *data = req->transport->negotiate.sign_info.signing_context;
+	const size_t offset_end_of_sig = (HDR_SS_FIELD + 8);
+	int i;
+	const int sign_range = 0;
+
+	/* its quite bogus to be guessing sequence numbers, but very useful
+	   when debugging signing implementations */
+	for (i = 1-sign_range; i <= 1+sign_range; i++) {
+		/*
+		 * Firstly put the sequence number into the first 4 bytes.
+		 * and zero out the next 4 bytes.
+		 */
+		SIVAL(sequence_buf, 0, req->seq_num+i);
+		SIVAL(sequence_buf, 4, 0);
+		
+		/* get a copy of the server-sent mac */
+		memcpy(server_sent_mac, &req->in.hdr[HDR_SS_FIELD], sizeof(server_sent_mac));
+		
+		/* Calculate the 16 byte MAC and place first 8 bytes into the field. */
+		MD5Init(&md5_ctx);
+		MD5Update(&md5_ctx, data->mac_key.data, 
+			  data->mac_key.length); 
+		MD5Update(&md5_ctx, req->in.hdr, HDR_SS_FIELD);
+		MD5Update(&md5_ctx, sequence_buf, sizeof(sequence_buf));
+		
+		MD5Update(&md5_ctx, req->in.hdr + offset_end_of_sig, 
+			  req->in.size - NBT_HDR_SIZE - (offset_end_of_sig));
+		MD5Final(calc_md5_mac, &md5_ctx);
+		
+		good = (memcmp(server_sent_mac, calc_md5_mac, 8) == 0);
+		if (good) break;
+	}
+
+	if (good && i != 1) {
+		DEBUG(0,("SIGNING OFFSET %d\n", i));
+	}
+
+	if (!good) {
+		DEBUG(5, ("cli_request_simple_check_incoming_message: BAD SIG: wanted SMB signature of\n"));
+		dump_data(5, calc_md5_mac, 8);
+		
+		DEBUG(5, ("cli_request_simple_check_incoming_message: BAD SIG: got SMB signature of\n"));
+		dump_data(5, server_sent_mac, 8);
+	}
+	return signing_good(req, good);
+}
+
+
+/***********************************************************
+ SMB signing - Simple implementation - free signing context
+************************************************************/
+static void cli_transport_simple_free_signing_context(struct cli_transport *transport)
+{
+	struct smb_basic_signing_context *data = transport->negotiate.sign_info.signing_context;
+
+	data_blob_free(&data->mac_key);
+	SAFE_FREE(transport->negotiate.sign_info.signing_context);
+
+	return;
+}
+
+
+/***********************************************************
+ SMB signing - Simple implementation - setup the MAC key.
+************************************************************/
+BOOL cli_transport_simple_set_signing(struct cli_transport *transport,
+				      const uchar user_transport_key[16], const DATA_BLOB response)
+{
+	struct smb_basic_signing_context *data;
+
+	if (!set_smb_signing_common(transport)) {
+		return False;
+	}
+
+	if (!set_smb_signing_real_common(transport)) {
+		return False;
+	}
+
+	data = smb_xmalloc(sizeof(*data));
+	transport->negotiate.sign_info.signing_context = data;
+	
+	data->mac_key = data_blob(NULL, MIN(response.length + 16, 40));
+
+	memcpy(&data->mac_key.data[0], user_transport_key, 16);
+	memcpy(&data->mac_key.data[16],response.data, MIN(response.length, 40 - 16));
+
+	/* Initialise the sequence number */
+	data->next_seq_num = 0;
+
+	transport->negotiate.sign_info.sign_outgoing_message = cli_request_simple_sign_outgoing_message;
+	transport->negotiate.sign_info.check_incoming_message = cli_request_simple_check_incoming_message;
+	transport->negotiate.sign_info.free_signing_context = cli_transport_simple_free_signing_context;
+
+	return True;
+}
+
+
+/***********************************************************
+ SMB signing - NULL implementation - calculate a MAC to send.
+************************************************************/
+static void cli_request_null_sign_outgoing_message(struct cli_request *req)
+{
+	/* we can't zero out the sig, as we might be trying to send a
+	   transport request - which is NBT-level, not SMB level and doesn't
+	   have the field */
+}
+
+
+/***********************************************************
+ SMB signing - NULL implementation - check a MAC sent by server.
+************************************************************/
+static BOOL cli_request_null_check_incoming_message(struct cli_request *req)
+{
+	return True;
+}
+
+
+/***********************************************************
+ SMB signing - NULL implementation - free signing context
+************************************************************/
+static void cli_null_free_signing_context(struct cli_transport *transport)
+{
+}
+
+/**
+ SMB signing - NULL implementation - setup the MAC key.
+
+ @note Used as an initialisation only - it will not correctly
+       shut down a real signing mechanism
+*/
+BOOL cli_null_set_signing(struct cli_transport *transport)
+{
+	transport->negotiate.sign_info.signing_context = NULL;
+	
+	transport->negotiate.sign_info.sign_outgoing_message = cli_request_null_sign_outgoing_message;
+	transport->negotiate.sign_info.check_incoming_message = cli_request_null_check_incoming_message;
+	transport->negotiate.sign_info.free_signing_context = cli_null_free_signing_context;
+
+	return True;
+}
+
+
+/**
+ * Free the signing context
+ */
+void cli_transport_free_signing_context(struct cli_transport *transport) 
+{
+	if (transport->negotiate.sign_info.free_signing_context) {
+		transport->negotiate.sign_info.free_signing_context(transport);
+	}
+
+	cli_null_set_signing(transport);
+}
+
+
+/**
+ * Sign a packet with the current mechanism
+ */
+void cli_request_calculate_sign_mac(struct cli_request *req)
+{
+	req->transport->negotiate.sign_info.sign_outgoing_message(req);
+}
+
+
+/**
+ * Check a packet with the current mechanism
+ * @return False if we had an established signing connection
+ *         which had a back checksum, True otherwise
+ */
+BOOL cli_request_check_sign_mac(struct cli_request *req) 
+{
+	BOOL good;
+
+	if (req->in.size < (HDR_SS_FIELD + 8)) {
+		good = False;
+	} else {
+		good = req->transport->negotiate.sign_info.check_incoming_message(req);
+	}
+
+	if (!good && req->transport->negotiate.sign_info.doing_signing) {
+		return False;
+	}
+
+	return True;
+}