/* Unix SMB/CIFS implementation. SMB2 Create Context Blob handling Copyright (C) Andrew Tridgell 2005 Copyright (C) Stefan Metzmacher 2008-2009 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" static size_t smb2_create_blob_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 blobs */ NTSTATUS smb2_create_blob_parse(TALLOC_CTX *mem_ctx, const DATA_BLOB buffer, struct smb2_create_blobs *blobs) { const uint8_t *data = buffer.data; uint32_t remaining = buffer.length; while (remaining > 0) { uint32_t next; uint32_t name_offset, name_length; uint32_t reserved, data_offset; uint32_t data_length; char *tag; DATA_BLOB b; NTSTATUS status; if (remaining < 16) { return NT_STATUS_INVALID_PARAMETER; } next = IVAL(data, 0); name_offset = SVAL(data, 4); name_length = SVAL(data, 6); reserved = SVAL(data, 8); data_offset = SVAL(data, 10); data_length = IVAL(data, 12); if ((next & 0x7) != 0 || next > remaining || name_offset < 16 || name_offset > remaining || name_length != 4 || /* windows enforces this */ name_offset + name_length > remaining || data_offset < name_offset + name_length || data_offset > remaining || data_offset + (uint64_t)data_length > remaining) { return NT_STATUS_INVALID_PARAMETER; } tag = talloc_strndup(mem_ctx, (const char *)data + name_offset, name_length); if (tag == NULL) { return NT_STATUS_NO_MEMORY; } b = data_blob_const(data+data_offset, data_length); status = smb2_create_blob_add(mem_ctx, blobs, tag, b); if (!NT_STATUS_IS_OK(status)) { return status; } talloc_free(tag); if (next == 0) break; remaining -= next; data += next; if (remaining < 16) { return NT_STATUS_INVALID_PARAMETER; } } return NT_STATUS_OK; } /* add a blob to a smb2_create attribute blob */ static NTSTATUS smb2_create_blob_push_one(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer, const struct smb2_create_blob *blob, bool last) { uint32_t ofs = buffer->length; size_t tag_length = strlen(blob->tag); uint8_t pad = smb2_create_blob_padding(blob->data.length+tag_length, 4); if (!data_blob_realloc(mem_ctx, buffer, buffer->length + 0x14 + tag_length + blob->data.length + pad)) return NT_STATUS_NO_MEMORY; if (last) { SIVAL(buffer->data, ofs+0x00, 0); } else { SIVAL(buffer->data, ofs+0x00, 0x14 + tag_length + blob->data.length + pad); } SSVAL(buffer->data, ofs+0x04, 0x10); /* offset of tag */ SIVAL(buffer->data, ofs+0x06, tag_length); /* tag length */ SSVAL(buffer->data, ofs+0x0A, 0x14 + tag_length); /* offset of data */ SIVAL(buffer->data, ofs+0x0C, blob->data.length); memcpy(buffer->data+ofs+0x10, blob->tag, tag_length); SIVAL(buffer->data, ofs+0x10+tag_length, 0); /* pad? */ memcpy(buffer->data+ofs+0x14+tag_length, blob->data.data, blob->data.length); memset(buffer->data+ofs+0x14+tag_length+blob->data.length, 0, pad); return NT_STATUS_OK; } /* create a buffer of a set of create blobs */ NTSTATUS smb2_create_blob_push(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer, const struct smb2_create_blobs blobs) { int i; NTSTATUS status; *buffer = data_blob(NULL, 0); for (i=0; i < blobs.num_blobs; i++) { bool last = false; const struct smb2_create_blob *c; if ((i + 1) == blobs.num_blobs) { last = true; } c = &blobs.blobs[i]; status = smb2_create_blob_push_one(mem_ctx, buffer, c, last); if (!NT_STATUS_IS_OK(status)) { return status; } } return NT_STATUS_OK; } NTSTATUS smb2_create_blob_add(TALLOC_CTX *mem_ctx, struct smb2_create_blobs *b, const char *tag, DATA_BLOB data) { struct smb2_create_blob *array; array = talloc_realloc(mem_ctx, b->blobs, struct smb2_create_blob, b->num_blobs + 1); NT_STATUS_HAVE_NO_MEMORY(array); b->blobs = array; b->blobs[b->num_blobs].tag = talloc_strdup(b->blobs, tag); NT_STATUS_HAVE_NO_MEMORY(b->blobs[b->num_blobs].tag); if (data.data) { b->blobs[b->num_blobs].data = data_blob_talloc(b->blobs, data.data, data.length); NT_STATUS_HAVE_NO_MEMORY(b->blobs[b->num_blobs].data.data); } else { b->blobs[b->num_blobs].data = data_blob(NULL, 0); } b->num_blobs += 1; return NT_STATUS_OK; } /* * return the first blob with the given tag */ struct smb2_create_blob *smb2_create_blob_find(const struct smb2_create_blobs *b, const char *tag) { uint32_t i; for (i=0; i < b->num_blobs; i++) { if (strcmp(b->blobs[i].tag, tag) == 0) { return &b->blobs[i]; } } return NULL; }