- modified the dcerpc client security code to be generic, so ntlmssp

  and schannel are both instances of possible security modules

- added schannel sign and sign/seal support to the dcerpc client
  code. You select it with binding options of "schannel,sign" or
  "schannel,seal".
(This used to be commit 05db0b9d942cad8f1dd574dc35b759e5e79d4195)

2 files changed, 344 insertions, 0 deletions

diff --git a/source4/libcli/auth/schannel.c b/source4/libcli/auth/schannel.c
new file mode 100644
index 0000000000..e5a786ff24
--- /dev/null
+++ b/source4/libcli/auth/schannel.c
@@ -0,0 +1,309 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   schannel library code
+
+   Copyright (C) Andrew Tridgell 2004
+   
+   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"
+
+/*******************************************************************
+ Encode or Decode the sequence number (which is symmetric)
+ ********************************************************************/
+static void netsec_deal_with_seq_num(struct schannel_state *state,
+				     const uchar packet_digest[8],
+				     uchar seq_num[8])
+{
+	static const uchar zeros[4];
+	uchar sequence_key[16];
+	uchar digest1[16];
+
+	hmac_md5(state->session_key, zeros, sizeof(zeros), digest1);
+	hmac_md5(digest1, packet_digest, 8, sequence_key);
+	SamOEMhash(seq_num, sequence_key, 8);
+
+	state->seq_num++;
+}
+
+
+/*******************************************************************
+ Calculate the key with which to encode the data payload 
+ ********************************************************************/
+static void netsec_get_sealing_key(const uchar session_key[16],
+				   const uchar seq_num[8],
+				   uchar sealing_key[16]) 
+{
+	static const uchar zeros[4];
+	uchar digest2[16];
+	uchar sess_kf0[16];
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		sess_kf0[i] = session_key[i] ^ 0xf0;
+	}
+	
+	hmac_md5(sess_kf0, zeros, 4, digest2);
+	hmac_md5(digest2, seq_num, 8, sealing_key);
+}
+
+
+/*******************************************************************
+ Create a digest over the entire packet (including the data), and 
+ MD5 it with the session key.
+ ********************************************************************/
+static void schannel_digest(const uchar sess_key[16],
+			    const uchar netsec_sig[8],
+			    const uchar *confounder,
+			    const uchar *data, size_t data_len,
+			    uchar digest_final[16]) 
+{
+	uchar packet_digest[16];
+	static const uchar zeros[4];
+	struct MD5Context ctx;
+	
+	MD5Init(&ctx);
+	MD5Update(&ctx, zeros, 4);
+	MD5Update(&ctx, netsec_sig, 8);
+	if (confounder) {
+		MD5Update(&ctx, confounder, 8);
+	}
+	MD5Update(&ctx, data, data_len);
+	MD5Final(packet_digest, &ctx);
+	
+	hmac_md5(sess_key, packet_digest, sizeof(packet_digest), digest_final);
+}
+
+
+/*
+  unseal a packet
+*/
+NTSTATUS schannel_unseal_packet(struct schannel_state *state,
+				uchar *data, size_t length, 
+				DATA_BLOB *sig)
+{
+	uchar digest_final[16];
+	uchar confounder[8];
+	uchar seq_num[8];
+	uchar sealing_key[16];
+	static const uchar netsec_sig[8] = NETSEC_SEAL_SIGNATURE;
+
+	if (sig->length != 32) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	memcpy(confounder, sig->data+24, 8);
+
+	RSIVAL(seq_num, 0, state->seq_num);
+	SIVAL(seq_num, 4, state->initiator?0:0x80);
+
+	netsec_get_sealing_key(state->session_key, seq_num, sealing_key);
+	SamOEMhash(confounder, sealing_key, 8);
+	SamOEMhash(data, sealing_key, length);
+
+	schannel_digest(state->session_key, 
+			netsec_sig, confounder, 
+			data, length, digest_final);
+
+	if (memcmp(digest_final, sig->data+16, 8) != 0) {
+		dump_data_pw("calc digest:", digest_final, 8);
+		dump_data_pw("wire digest:", sig->data+16, 8);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+	if (memcmp(seq_num, sig->data+8, 8) != 0) {
+		dump_data_pw("calc seq num:", seq_num, 8);
+		dump_data_pw("wire seq num:", sig->data+8, 8);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+  check the signature on a packet
+*/
+NTSTATUS schannel_check_packet(struct schannel_state *state, 
+			       const uchar *data, size_t length, 
+			       const DATA_BLOB *sig)
+{
+	uchar digest_final[16];
+	uchar seq_num[8];
+	static const uchar netsec_sig[8] = NETSEC_SIGN_SIGNATURE;
+
+	if (sig->length != 32) {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	RSIVAL(seq_num, 0, state->seq_num);
+	SIVAL(seq_num, 4, state->initiator?0:0x80);
+
+	dump_data_pw("seq_num:\n", seq_num, 8);
+	dump_data_pw("sess_key:\n", state->session_key, 16);
+
+	schannel_digest(state->session_key, 
+			netsec_sig, NULL, 
+			data, length, digest_final);
+
+	netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+	if (memcmp(seq_num, sig->data+8, 8) != 0) {
+		dump_data_pw("calc seq num:", seq_num, 8);
+		dump_data_pw("wire seq num:", sig->data+8, 8);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	if (memcmp(digest_final, sig->data+16, 8) != 0) {
+		dump_data_pw("calc digest:", digest_final, 8);
+		dump_data_pw("wire digest:", sig->data+16, 8);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	return NT_STATUS_OK;
+}
+
+
+/*
+  seal a packet
+*/
+NTSTATUS schannel_seal_packet(struct schannel_state *state, 
+			      uchar *data, size_t length, 
+			      DATA_BLOB *sig)
+{
+	uchar digest_final[16];
+	uchar confounder[8];
+	uchar seq_num[8];
+	uchar sealing_key[16];
+	static const uchar netsec_sig[8] = NETSEC_SEAL_SIGNATURE;
+
+	generate_random_buffer(confounder, 8, False);
+
+	RSIVAL(seq_num, 0, state->seq_num);
+	SIVAL(seq_num, 4, state->initiator?0x80:0);
+
+	schannel_digest(state->session_key, 
+			netsec_sig, confounder, 
+			data, length, digest_final);
+
+	netsec_get_sealing_key(state->session_key, seq_num, sealing_key);
+	SamOEMhash(confounder, sealing_key, 8);
+	SamOEMhash(data, sealing_key, length);
+
+	netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+	if (!state->signature.data) {
+		state->signature = data_blob_talloc(state->mem_ctx, NULL, 32);
+		if (!state->signature.data) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	(*sig) = state->signature;
+
+	memcpy(sig->data, netsec_sig, 8);
+	memcpy(sig->data+8, seq_num, 8);
+	memcpy(sig->data+16, digest_final, 8);
+	memcpy(sig->data+24, confounder, 8);
+
+	dump_data_pw("signature:", sig->data+ 0, 8);
+	dump_data_pw("seq_num  :", sig->data+ 8, 8);
+	dump_data_pw("digest   :", sig->data+16, 8);
+	dump_data_pw("confound :", sig->data+24, 8);
+
+	return NT_STATUS_OK;
+}
+
+
+/*
+  sign a packet
+*/
+NTSTATUS schannel_sign_packet(struct schannel_state *state, 
+			      const uchar *data, size_t length, 
+			      DATA_BLOB *sig)
+{
+	uchar digest_final[16];
+	uchar seq_num[8];
+	static const uchar netsec_sig[8] = NETSEC_SIGN_SIGNATURE;
+
+	RSIVAL(seq_num, 0, state->seq_num);
+	SIVAL(seq_num, 4, state->initiator?0x80:0);
+
+	schannel_digest(state->session_key, 
+			netsec_sig, NULL, 
+			data, length, digest_final);
+
+	netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+	if (!state->signature.data) {
+		state->signature = data_blob_talloc(state->mem_ctx, NULL, 32);
+		if (!state->signature.data) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	(*sig) = state->signature;
+
+	memcpy(sig->data, netsec_sig, 8);
+	memcpy(sig->data+8, seq_num, 8);
+	memcpy(sig->data+16, digest_final, 8);
+	memset(sig->data+24, 0, 8);
+
+	dump_data_pw("signature:", sig->data+ 0, 8);
+	dump_data_pw("seq_num  :", sig->data+ 8, 8);
+	dump_data_pw("digest   :", sig->data+16, 8);
+	dump_data_pw("confound :", sig->data+24, 8);
+
+	return NT_STATUS_OK;
+}
+
+/*
+  destroy an schannel context
+ */
+void schannel_end(struct schannel_state **state)
+{
+	talloc_destroy((*state)->mem_ctx);
+	(*state) = NULL;
+}
+
+/*
+  create an schannel context state
+*/
+NTSTATUS schannel_start(struct schannel_state **state,
+			uint8 session_key[16],
+			BOOL initiator)
+{
+	TALLOC_CTX *mem_ctx;
+
+	mem_ctx = talloc_init("schannel_state");
+	if (!mem_ctx) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	(*state) = talloc_p(mem_ctx, struct schannel_state);
+	if (!(*state)) {
+		talloc_destroy(mem_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	(*state)->mem_ctx = mem_ctx;
+	memcpy((*state)->session_key, session_key, 16);
+	(*state)->initiator = initiator;
+	(*state)->signature = data_blob(NULL, 0);
+	(*state)->seq_num = 0;
+
+	return NT_STATUS_OK;
+}
diff --git a/source4/libcli/auth/schannel.h b/source4/libcli/auth/schannel.h
new file mode 100644
index 0000000000..7b710d7cb9
--- /dev/null
+++ b/source4/libcli/auth/schannel.h
@@ -0,0 +1,35 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   schannel library code
+
+   Copyright (C) Andrew Tridgell 2004
+   
+   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 schannel_state {
+	TALLOC_CTX *mem_ctx;
+	uint8 session_key[16];
+	uint32 seq_num;
+	BOOL initiator;
+	DATA_BLOB signature;
+};
+
+#define NETSEC_SIGN_SIGNATURE { 0x77, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00 }
+#define NETSEC_SEAL_SIGNATURE { 0x77, 0x00, 0x7a, 0x00, 0xff, 0xff, 0x00, 0x00 }
+