libcli/smb: add smb2_negotiate_context.c

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

3 files changed, 248 insertions, 0 deletions

diff --git a/libcli/smb/smb2_negotiate_context.c b/libcli/smb/smb2_negotiate_context.c
new file mode 100644
index 0000000000..61c9e557e3
--- /dev/null
+++ b/libcli/smb/smb2_negotiate_context.c
@@ -0,0 +1,193 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Copyright (C) Stefan Metzmacher 2014
+
+   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 "../libcli/smb/smb_common.h"
+#include "libcli/smb/smb2_negotiate_context.h"
+
+static size_t smb2_negotiate_context_padding(uint32_t offset, size_t n)
+{
+	if ((offset & (n-1)) == 0) return 0;
+	return n - (offset & (n-1));
+}
+
+/*
+  parse a set of SMB2 create contexts
+*/
+NTSTATUS smb2_negotiate_context_parse(TALLOC_CTX *mem_ctx, const DATA_BLOB buffer,
+				      struct smb2_negotiate_contexts *contexts)
+{
+	const uint8_t *data = buffer.data;
+	uint32_t remaining = buffer.length;
+
+	while (true) {
+		uint16_t data_length;
+		uint16_t type;
+		DATA_BLOB b;
+		NTSTATUS status;
+		size_t pad;
+		uint32_t next_offset;
+
+		if (remaining < 8) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+		type        = SVAL(data, 0x00);
+		data_length = SVAL(data, 0x02);
+#if 0
+		reserved    = IVAL(data, 0x04);
+#endif
+
+		next_offset = 0x08 + data_length;
+		if (remaining < next_offset) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+
+		b = data_blob_const(data+0x08, data_length);
+		status = smb2_negotiate_context_add(mem_ctx, contexts, type, b);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+
+		remaining -= next_offset;
+		data += next_offset;
+
+		if (remaining == 0) {
+			break;
+		}
+
+		pad = smb2_negotiate_context_padding(next_offset, 8);
+		if (remaining < pad) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+		remaining -= pad;
+		data += pad;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+  add a context to a smb2_negotiate attribute context
+*/
+static NTSTATUS smb2_negotiate_context_push_one(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer,
+					  const struct smb2_negotiate_context *context,
+					  bool last)
+{
+	uint32_t ofs = buffer->length;
+	size_t next_offset = 0;
+	size_t next_pad = 0;
+	bool ok;
+
+	if (context->data.length > UINT16_MAX) {
+		return NT_STATUS_INVALID_PARAMETER_MIX;
+	}
+
+	next_offset = 0x08 + context->data.length;
+	if (!last) {
+		next_pad = smb2_negotiate_context_padding(next_offset, 8);
+	}
+
+	ok = data_blob_realloc(mem_ctx, buffer,
+			       buffer->length + next_offset + next_pad);
+	if (!ok) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	SSVAL(buffer->data, ofs+0x00, context->type);
+	SIVAL(buffer->data, ofs+0x02, context->data.length);
+	SIVAL(buffer->data, ofs+0x04, 0);
+	memcpy(buffer->data+ofs+0x08, context->data.data, context->data.length);
+	if (next_pad > 0) {
+		memset(buffer->data+ofs+next_offset, 0, next_pad);
+		next_offset += next_pad;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+  create a buffer of a set of create contexts
+*/
+NTSTATUS smb2_negotiate_context_push(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer,
+				     const struct smb2_negotiate_contexts contexts)
+{
+	int i;
+	NTSTATUS status;
+
+	*buffer = data_blob(NULL, 0);
+	for (i=0; i < contexts.num_contexts; i++) {
+		bool last = false;
+		const struct smb2_negotiate_context *c;
+
+		if ((i + 1) == contexts.num_contexts) {
+			last = true;
+		}
+
+		c = &contexts.contexts[i];
+		status = smb2_negotiate_context_push_one(mem_ctx, buffer, c, last);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+	}
+	return NT_STATUS_OK;
+}
+
+NTSTATUS smb2_negotiate_context_add(TALLOC_CTX *mem_ctx, struct smb2_negotiate_contexts *c,
+				    uint16_t type, DATA_BLOB data)
+{
+	struct smb2_negotiate_context *array;
+
+	array = talloc_realloc(mem_ctx, c->contexts,
+			       struct smb2_negotiate_context,
+			       c->num_contexts + 1);
+	NT_STATUS_HAVE_NO_MEMORY(array);
+	c->contexts = array;
+
+	c->contexts[c->num_contexts].type = type;
+
+	if (data.data) {
+		c->contexts[c->num_contexts].data = data_blob_talloc(c->contexts,
+								     data.data,
+								     data.length);
+		NT_STATUS_HAVE_NO_MEMORY(c->contexts[c->num_contexts].data.data);
+	} else {
+		c->contexts[c->num_contexts].data = data_blob_null;
+	}
+
+	c->num_contexts += 1;
+
+	return NT_STATUS_OK;
+}
+
+/*
+ * return the first blob with the given tag
+ */
+struct smb2_negotiate_context *smb2_negotiate_context_find(const struct smb2_negotiate_contexts *c,
+							   uint16_t type)
+{
+	uint32_t i;
+
+	for (i=0; i < c->num_contexts; i++) {
+		if (c->contexts[i].type ==  type) {
+			return &c->contexts[i];
+		}
+	}
+
+	return NULL;
+}
diff --git a/libcli/smb/smb2_negotiate_context.h b/libcli/smb/smb2_negotiate_context.h
new file mode 100644
index 0000000000..d98104a1a7
--- /dev/null
+++ b/libcli/smb/smb2_negotiate_context.h
@@ -0,0 +1,54 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Copyright (C) Stefan Metzmacher 2014
+
+   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/>.
+*/
+
+#ifndef _LIBCLI_SMB_SMB2_NEGOTIATE_BLOB_H_
+#define _LIBCLI_SMB_SMB2_NEGOTIATE_BLOB_H_
+
+struct smb2_negotiate_context {
+	uint16_t type;
+	DATA_BLOB data;
+};
+
+struct smb2_negotiate_contexts {
+	uint32_t num_contexts;
+	struct smb2_negotiate_context *contexts;
+};
+
+/*
+  parse a set of SMB2 negotiate contexts
+*/
+NTSTATUS smb2_negotiate_context_parse(TALLOC_CTX *mem_ctx, const DATA_BLOB buffer,
+				struct smb2_negotiate_contexts *contexts);
+
+/*
+  negotiate a buffer of a set of negotiate contexts
+*/
+NTSTATUS smb2_negotiate_context_push(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer,
+			       const struct smb2_negotiate_contexts contexts);
+
+NTSTATUS smb2_negotiate_context_add(TALLOC_CTX *mem_ctx, struct smb2_negotiate_contexts *c,
+				    uint16_t type, DATA_BLOB data);
+
+/*
+ * return the first context with the given tag
+ */
+struct smb2_negotiate_context *smb2_negotiate_context_find(const struct smb2_negotiate_contexts *b,
+							   uint16_t type);
+
+#endif /* _LIBCLI_SMB_SMB2_NEGOTIATE_BLOB_H_ */
diff --git a/libcli/smb/wscript b/libcli/smb/wscript
index f2d1102e9b..48fa2b4e26 100755
--- a/libcli/smb/wscript
+++ b/libcli/smb/wscript
@@ -17,6 +17,7 @@ def build(bld):
     bld.SAMBA_LIBRARY('cli_smb_common',
 	source='''
 		smb_signing.c smb_seal.c
+        smb2_negotiate_context.c
 		smb2_create_blob.c smb2_signing.c
                 smb2_lease.c
 		util.c