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-rw-r--r--libcli/smb/smb2_negotiate_context.c203
1 files changed, 203 insertions, 0 deletions
diff --git a/libcli/smb/smb2_negotiate_context.c b/libcli/smb/smb2_negotiate_context.c
new file mode 100644
index 0000000..9ec20bc
--- /dev/null
+++ b/libcli/smb/smb2_negotiate_context.c
@@ -0,0 +1,203 @@
+/*
+ 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,
+ uint16_t expected_count,
+ struct smb2_negotiate_contexts *contexts)
+{
+ const uint8_t *data = buffer.data;
+ uint32_t remaining = buffer.length;
+ uint16_t idx;
+
+ for (idx = 0; idx < expected_count; idx++) {
+ uint16_t data_length;
+ uint16_t type;
+ 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;
+ }
+
+ status = smb2_negotiate_context_add(
+ mem_ctx, contexts, type, data+0x08, data_length);
+ if (!NT_STATUS_IS_OK(status)) {
+ return status;
+ }
+
+ if (contexts->num_contexts == expected_count) {
+ break;
+ }
+
+ 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;
+ }
+
+ if (contexts->num_contexts != expected_count) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ 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);
+ }
+
+ 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)
+{
+ uint32_t 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,
+ const uint8_t *buf,
+ size_t buflen)
+{
+ 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 (buf != NULL) {
+ c->contexts[c->num_contexts].data = data_blob_talloc(
+ c->contexts, buf, buflen);
+ 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;
+}