Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 220 insertions, 0 deletions

diff --git a/libcli/smb/smb_seal.c b/libcli/smb/smb_seal.c
new file mode 100644
index 0000000..079744c
--- /dev/null
+++ b/libcli/smb/smb_seal.c
@@ -0,0 +1,220 @@
+/*
+   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 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 "smb_common.h"
+#ifdef HAVE_KRB5
+#include "lib/krb5_wrap/krb5_samba.h"
+#endif
+#include "auth/gensec/gensec.h"
+#include "libcli/smb/smb_seal.h"
+
+#undef malloc
+
+/******************************************************************************
+ Pull out the encryption context for this packet. 0 means global context.
+******************************************************************************/
+
+NTSTATUS get_enc_ctx_num(const uint8_t *buf, uint16_t *p_enc_ctx_num)
+{
+	if (smb_len_nbt(buf) < 8) {
+		return NT_STATUS_INVALID_BUFFER_SIZE;
+	}
+
+	if (buf[4] == 0xFF) {
+		if (buf[5] == 'S' && buf [6] == 'M' && buf[7] == 'B') {
+			/* Not an encrypted buffer. */
+			return NT_STATUS_NOT_FOUND;
+		}
+		if (buf[5] == 'E') {
+			*p_enc_ctx_num = SVAL(buf,6);
+			return NT_STATUS_OK;
+		}
+	}
+	return NT_STATUS_INVALID_NETWORK_RESPONSE;
+}
+
+/*******************************************************************
+ Set the length and marker of an encrypted smb packet.
+********************************************************************/
+
+static void smb_set_enclen(char *buf,int len,uint16_t enc_ctx_num)
+{
+	_smb_setlen_tcp(buf,len);
+
+	SCVAL(buf,4,0xFF);
+	SCVAL(buf,5,'E');
+	SSVAL(buf,6,enc_ctx_num);
+}
+
+/******************************************************************************
+ 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.
+ GENSEC decrypt an incoming buffer.
+******************************************************************************/
+
+static NTSTATUS common_gensec_decrypt_buffer(struct gensec_security *gensec,
+					     char *buf)
+{
+	NTSTATUS status;
+	size_t buf_len = smb_len_nbt(buf) + 4; /* Don't forget the 4 length bytes. */
+	DATA_BLOB in_buf, out_buf;
+	TALLOC_CTX *frame;
+
+	if (buf_len < 8) {
+		return NT_STATUS_BUFFER_TOO_SMALL;
+	}
+
+	frame = talloc_stackframe();
+
+	in_buf = data_blob_const(buf + 8, buf_len - 8);
+
+	status = gensec_unwrap(gensec, frame, &in_buf, &out_buf);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("common_gensec_decrypt_buffer: gensec_unwrap failed. Error %s\n",
+			 nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	if (out_buf.length > in_buf.length) {
+		DEBUG(0,("common_gensec_decrypt_buffer: gensec_unwrap size (%u) too large (%u) !\n",
+			(unsigned int)out_buf.length,
+			(unsigned int)in_buf.length ));
+		TALLOC_FREE(frame);
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	memcpy(buf + 8, out_buf.data, out_buf.length);
+
+	/* Reset the length and overwrite the header. */
+	smb_setlen_nbt(buf, out_buf.length + 4);
+
+	TALLOC_FREE(frame);
+
+	return NT_STATUS_OK;
+}
+
+/******************************************************************************
+ Generic code for client and server.
+ NTLM encrypt an outgoing buffer. Return the encrypted pointer in ppbuf_out.
+******************************************************************************/
+
+static NTSTATUS common_gensec_encrypt_buffer(struct gensec_security *gensec,
+				      uint16_t enc_ctx_num,
+				      char *buf,
+				      char **ppbuf_out)
+{
+	NTSTATUS status;
+	DATA_BLOB in_buf, out_buf;
+	size_t buf_len = smb_len_nbt(buf) + 4; /* Don't forget the 4 length bytes. */
+	TALLOC_CTX *frame;
+
+	*ppbuf_out = NULL;
+
+	if (buf_len < 8) {
+		return NT_STATUS_BUFFER_TOO_SMALL;
+	}
+	in_buf = data_blob_const(buf + 8, buf_len - 8);
+
+	frame = talloc_stackframe();
+
+	status = gensec_wrap(gensec, frame, &in_buf, &out_buf);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("common_gensec_encrypt_buffer: gensec_wrap failed. Error %s\n",
+			 nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	*ppbuf_out = (char *)malloc(out_buf.length + 8); /* We know this can't wrap. */
+	if (!*ppbuf_out) {
+		TALLOC_FREE(frame);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	memcpy(*ppbuf_out+8, out_buf.data, out_buf.length);
+	smb_set_enclen(*ppbuf_out, out_buf.length + 4, enc_ctx_num);
+
+	TALLOC_FREE(frame);
+
+	return NT_STATUS_OK;
+}
+
+/******************************************************************************
+ 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;
+	}
+
+	return common_gensec_encrypt_buffer(es->gensec_security, es->enc_ctx_num, buffer, buf_out);
+}
+
+/******************************************************************************
+ 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;
+	}
+
+	return common_gensec_decrypt_buffer(es->gensec_security, buf);
+}
+
+/******************************************************************************
+ Free an encryption-allocated buffer.
+******************************************************************************/
+
+void common_free_enc_buffer(struct smb_trans_enc_state *es, char *buf)
+{
+	uint16_t enc_ctx_num;
+
+	if (!common_encryption_on(es)) {
+		return;
+	}
+
+	if (!NT_STATUS_IS_OK(get_enc_ctx_num((const uint8_t *)buf,
+			&enc_ctx_num))) {
+		return;
+	}
+
+	SAFE_FREE(buf);
+}