/*
* Copyright (C) 2013-2019 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2013 Sourcefire, Inc.
*
* Authors: David Raynor <draynor@sourcefire.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include "clamav.h"
#include "others.h"
#include "hfsplus.h"
#include "scanners.h"
static void headerrecord_to_host(hfsHeaderRecord *);
static void headerrecord_print(const char *, hfsHeaderRecord *);
static void nodedescriptor_to_host(hfsNodeDescriptor *);
static void nodedescriptor_print(const char *, hfsNodeDescriptor *);
static void forkdata_to_host(hfsPlusForkData *);
static void forkdata_print(const char *, hfsPlusForkData *);
static int hfsplus_volumeheader(cli_ctx *, hfsPlusVolumeHeader **);
static int hfsplus_readheader(cli_ctx *, hfsPlusVolumeHeader *, hfsNodeDescriptor *,
hfsHeaderRecord *, int, const char *);
static int hfsplus_scanfile(cli_ctx *, hfsPlusVolumeHeader *, hfsHeaderRecord *,
hfsPlusForkData *, const char *);
static int hfsplus_validate_catalog(cli_ctx *, hfsPlusVolumeHeader *, hfsHeaderRecord *);
static int hfsplus_fetch_node (cli_ctx *, hfsPlusVolumeHeader *, hfsHeaderRecord *,
hfsHeaderRecord *, uint32_t, uint8_t *);
static int hfsplus_walk_catalog(cli_ctx *, hfsPlusVolumeHeader *, hfsHeaderRecord *,
hfsHeaderRecord *, const char *);
/* Header Record : fix endianness for useful fields */
static void headerrecord_to_host(hfsHeaderRecord *hdr)
{
hdr->treeDepth = be16_to_host(hdr->treeDepth);
hdr->rootNode = be32_to_host(hdr->rootNode);
hdr->leafRecords = be32_to_host(hdr->leafRecords);
hdr->firstLeafNode = be32_to_host(hdr->firstLeafNode);
hdr->lastLeafNode = be32_to_host(hdr->lastLeafNode);
hdr->nodeSize = be16_to_host(hdr->nodeSize);
hdr->maxKeyLength = be16_to_host(hdr->maxKeyLength);
hdr->totalNodes = be32_to_host(hdr->totalNodes);
hdr->freeNodes = be32_to_host(hdr->freeNodes);
hdr->attributes = be32_to_host(hdr->attributes); /* not too useful */
}
/* Header Record : print details in debug mode */
static void headerrecord_print(const char *pfx, hfsHeaderRecord *hdr)
{
cli_dbgmsg("%s Header: depth %hu root %u leafRecords %u firstLeaf %u lastLeaf %u nodeSize %hu\n",
pfx, hdr->treeDepth, hdr->rootNode, hdr->leafRecords, hdr->firstLeafNode,
hdr->lastLeafNode, hdr->nodeSize);
cli_dbgmsg("%s Header: maxKeyLength %hu totalNodes %u freeNodes %u btreeType %hhu attributes %x\n",
pfx, hdr->maxKeyLength, hdr->totalNodes, hdr->freeNodes,
hdr->btreeType, hdr->attributes);
}
/* Node Descriptor : fix endianness for useful fields */
static void nodedescriptor_to_host(hfsNodeDescriptor *node)
{
node->fLink = be32_to_host(node->fLink);
node->bLink = be32_to_host(node->bLink);
node->numRecords = be16_to_host(node->numRecords);
}
/* Node Descriptor : print details in debug mode */
static void nodedescriptor_print(const char *pfx, hfsNodeDescriptor *node)
{
cli_dbgmsg("%s Desc: fLink %u bLink %u kind %d height %u numRecords %u\n",
pfx, node->fLink, node->bLink, node->kind, node->height, node->numRecords);
}
/* ForkData : fix endianness */
static void forkdata_to_host(hfsPlusForkData *fork)
{
int i;
fork->logicalSize = be64_to_host(fork->logicalSize);
fork->clumpSize = be32_to_host(fork->clumpSize); /* does this matter for read-only? */
fork->totalBlocks = be32_to_host(fork->totalBlocks);
for (i=0; i < 8; i++) {
fork->extents[i].startBlock = be32_to_host(fork->extents[i].startBlock);
fork->extents[i].blockCount = be32_to_host(fork->extents[i].blockCount);
}
}
/* ForkData : print details in debug mode */
static void forkdata_print(const char *pfx, hfsPlusForkData *fork)
{
int i;
cli_dbgmsg("%s logicalSize " STDu64 " clumpSize " STDu32 " totalBlocks " STDu32 "\n", pfx,
fork->logicalSize, fork->clumpSize, fork->totalBlocks);
for (i=0; i < 8; i++) {
if (fork->extents[i].startBlock == 0)
break;
cli_dbgmsg("%s extent[%d] startBlock " STDu32 " blockCount " STDu32 "\n", pfx, i,
fork->extents[i].startBlock, fork->extents[i].blockCount);
}
}
/* Read and convert the HFS+ volume header */
static int hfsplus_volumeheader(cli_ctx *ctx, hfsPlusVolumeHeader **header)
{
hfsPlusVolumeHeader *volHeader;
const uint8_t *mPtr;
if (!header) {
return CL_ENULLARG;
}
/* Start with volume header, 512 bytes at offset 1024 */
if ((*ctx->fmap)->len < 1536) {
cli_dbgmsg("cli_scanhfsplus: too short for HFS+\n");
return CL_EFORMAT;
}
mPtr = fmap_need_off_once(*ctx->fmap, 1024, 512);
if (!mPtr) {
cli_errmsg("cli_scanhfsplus: cannot read header from map\n");
return CL_EMAP;
}
volHeader = cli_malloc(sizeof(hfsPlusVolumeHeader));
if (!volHeader) {
cli_errmsg("cli_scanhfsplus: header malloc failed\n");
return CL_EMEM;
}
*header = volHeader;
memcpy(volHeader, mPtr, 512);
volHeader->signature = be16_to_host(volHeader->signature);
volHeader->version = be16_to_host(volHeader->version);
if ((volHeader->signature == 0x482B) && (volHeader->version == 4)) {
cli_dbgmsg("cli_scanhfsplus: HFS+ signature matched\n");
}
else if ((volHeader->signature == 0x4858) && (volHeader->version == 5)) {
cli_dbgmsg("cli_scanhfsplus: HFSX v5 signature matched\n");
}
else {
cli_dbgmsg("cli_scanhfsplus: no matching signature\n");
return CL_EFORMAT;
}
/* skip fields that will definitely be ignored */
volHeader->attributes = be32_to_host(volHeader->attributes);
volHeader->fileCount = be32_to_host(volHeader->fileCount);
volHeader->folderCount = be32_to_host(volHeader->folderCount);
volHeader->blockSize = be32_to_host(volHeader->blockSize);
volHeader->totalBlocks = be32_to_host(volHeader->totalBlocks);
cli_dbgmsg("HFS+ Header:\n");
cli_dbgmsg("Signature: %x\n", volHeader->signature);
cli_dbgmsg("Attributes: %x\n", volHeader->attributes);
cli_dbgmsg("File Count: " STDu32 "\n", volHeader->fileCount);
cli_dbgmsg("Folder Count: " STDu32 "\n", volHeader->folderCount);
cli_dbgmsg("Block Size: " STDu32 "\n", volHeader->blockSize);
cli_dbgmsg("Total Blocks: " STDu32 "\n", volHeader->totalBlocks);
/* Block Size must be power of 2 between 512 and 1 MB */
if ((volHeader->blockSize < 512) || (volHeader->blockSize > (1 << 20))) {
cli_dbgmsg("cli_scanhfsplus: Invalid blocksize\n");
return CL_EFORMAT;
}
if (volHeader->blockSize & (volHeader->blockSize - 1)) {
cli_dbgmsg("cli_scanhfsplus: Invalid blocksize\n");
return CL_EFORMAT;
}
forkdata_to_host(&(volHeader->allocationFile));
forkdata_to_host(&(volHeader->extentsFile));
forkdata_to_host(&(volHeader->catalogFile));
forkdata_to_host(&(volHeader->attributesFile));
forkdata_to_host(&(volHeader->startupFile));
if (cli_debug_flag) {
forkdata_print("allocationFile", &(volHeader->allocationFile));
forkdata_print("extentsFile", &(volHeader->extentsFile));
forkdata_print("catalogFile", &(volHeader->catalogFile));
forkdata_print("attributesFile", &(volHeader->attributesFile));
forkdata_print("startupFile", &(volHeader->startupFile));
}
return CL_CLEAN;
}
/* Read and convert the header node */
static int hfsplus_readheader(cli_ctx *ctx, hfsPlusVolumeHeader *volHeader, hfsNodeDescriptor *nodeDesc,
hfsHeaderRecord *headerRec, int headerType, const char *name)
{
const uint8_t *mPtr = NULL;
off_t offset;
uint32_t minSize, maxSize;
/* From TN1150: Node Size must be power of 2 between 512 and 32768 */
/* Node Size for Catalog or Attributes must be at least 4096 */
maxSize = 32768; /* Doesn't seem to vary */
switch (headerType) {
case HFS_FILETREE_ALLOCATION:
offset = volHeader->allocationFile.extents[0].startBlock * volHeader->blockSize;
minSize = 512;
break;
case HFS_FILETREE_EXTENTS:
offset = volHeader->extentsFile.extents[0].startBlock * volHeader->blockSize;
minSize = 512;
break;
case HFS_FILETREE_CATALOG:
offset = volHeader->catalogFile.extents[0].startBlock * volHeader->blockSize;
minSize = 4096;
break;
case HFS_FILETREE_ATTRIBUTES:
offset = volHeader->attributesFile.extents[0].startBlock * volHeader->blockSize;
minSize = 4096;
break;
case HFS_FILETREE_STARTUP:
offset = volHeader->startupFile.extents[0].startBlock * volHeader->blockSize;
minSize = 512;
break;
default:
cli_errmsg("hfsplus_readheader: %s: invalid headerType %d\n", name, headerType);
return CL_EARG;
}
mPtr = fmap_need_off_once(*ctx->fmap, offset, volHeader->blockSize);
if (!mPtr) {
cli_dbgmsg("hfsplus_header: %s: headerNode is out-of-range\n", name);
return CL_EFORMAT;
}
/* Node descriptor first */
memcpy(nodeDesc, mPtr, sizeof(hfsNodeDescriptor));
nodedescriptor_to_host(nodeDesc);
nodedescriptor_print(name, nodeDesc);
if (nodeDesc->kind != HFS_NODEKIND_HEADER) {
cli_dbgmsg("hfsplus_header: %s: headerNode not header kind\n", name);
return CL_EFORMAT;
}
if ((nodeDesc->bLink != 0) || (nodeDesc->height != 0) || (nodeDesc->numRecords != 3)) {
cli_dbgmsg("hfsplus_header: %s: Invalid headerNode\n", name);
return CL_EFORMAT;
}
/* Then header record */
memcpy(headerRec, mPtr + sizeof(hfsNodeDescriptor), sizeof(hfsHeaderRecord));
headerrecord_to_host(headerRec);
headerrecord_print(name, headerRec);
if ((headerRec->nodeSize < minSize) || (headerRec->nodeSize > maxSize)) {
cli_dbgmsg("hfsplus_header: %s: Invalid nodesize\n", name);
return CL_EFORMAT;
}
if (headerRec->nodeSize & (headerRec->nodeSize - 1)) {
cli_dbgmsg("hfsplus_header: %s: Invalid nodesize\n", name);
return CL_EFORMAT;
}
/* KeyLength must be between 6 and 516 for catalog */
if (headerType == HFS_FILETREE_CATALOG) {
if ((headerRec->maxKeyLength < 6) || (headerRec->maxKeyLength > 516)) {
cli_dbgmsg("hfsplus_header: %s: Invalid cat maxKeyLength\n", name);
return CL_EFORMAT;
}
if (headerRec->maxKeyLength > (headerRec->nodeSize / 2)) {
cli_dbgmsg("hfsplus_header: %s: Invalid cat maxKeyLength based on nodeSize\n", name);
return CL_EFORMAT;
}
}
else if (headerType == HFS_FILETREE_EXTENTS) {
if (headerRec->maxKeyLength != 10) {
cli_dbgmsg("hfsplus_header: %s: Invalid ext maxKeyLength\n", name);
return CL_EFORMAT;
}
}
/* hdr->treeDepth = rootnode->height */
return CL_CLEAN;
}
/* Read and dump a file for scanning */
static int hfsplus_scanfile(cli_ctx *ctx, hfsPlusVolumeHeader *volHeader, hfsHeaderRecord *extHeader,
hfsPlusForkData *fork, const char *dirname)
{
hfsPlusExtentDescriptor *currExt;
const uint8_t *mPtr = NULL;
char *tmpname = NULL;
int ofd, ret = CL_CLEAN;
uint64_t targetSize;
uint32_t outputBlocks = 0;
uint8_t ext;
UNUSEDPARAM(extHeader);
/* bad record checks */
if (!fork || (fork->logicalSize == 0) || (fork->totalBlocks == 0)) {
cli_dbgmsg("hfsplus_dumpfile: Empty file.\n");
return CL_CLEAN;
}
/* check limits */
targetSize = fork->logicalSize;
#if SIZEOF_LONG < 8
if (targetSize > ULONG_MAX) {
cli_dbgmsg("hfsplus_dumpfile: File too large for limit check.\n");
return CL_EFORMAT;
}
#endif
ret = cli_checklimits("hfsplus_scanfile", ctx, (unsigned long)targetSize, 0, 0);
if (ret != CL_CLEAN) {
return ret;
}
/* open file */
ret = cli_gentempfd(dirname, &tmpname, &ofd);
if (ret != CL_CLEAN) {
cli_dbgmsg("hfsplus_dumpfile: Cannot generate temporary file.\n");
return ret;
}
cli_dbgmsg("hfsplus_dumpfile: Extracting to %s\n", tmpname);
ext = 0;
/* Dump file, extent by extent */
do {
uint32_t currBlock, endBlock, outputSize = 0;
if (targetSize == 0) {
cli_dbgmsg("hfsplus_dumpfile: output complete\n");
break;
}
if (outputBlocks >= fork->totalBlocks) {
cli_dbgmsg("hfsplus_dumpfile: output all blocks, remaining size " STDu64 "\n", targetSize);
break;
}
/* Prepare extent */
if (ext < 8) {
currExt = &(fork->extents[ext]);
cli_dbgmsg("hfsplus_dumpfile: extent %u\n", ext);
}
else {
cli_dbgmsg("hfsplus_dumpfile: need next extent from ExtentOverflow\n");
/* Not implemented yet */
ret = CL_EFORMAT;
break;
}
/* have extent, so validate and get block range */
if ((currExt->startBlock == 0) || (currExt->blockCount == 0)) {
cli_dbgmsg("hfsplus_dumpfile: next extent empty, done\n");
break;
}
if ((currExt->startBlock & 0x10000000) && (currExt->blockCount & 0x10000000)) {
cli_dbgmsg("hfsplus_dumpfile: next extent illegal!\n");
ret = CL_EFORMAT;
break;
}
currBlock = currExt->startBlock;
endBlock = currExt->startBlock + currExt->blockCount - 1;
if ((currBlock > volHeader->totalBlocks) || (endBlock > volHeader->totalBlocks)
|| (currExt->blockCount > volHeader->totalBlocks)) {
cli_dbgmsg("hfsplus_dumpfile: bad extent!\n");
ret = CL_EFORMAT;
break;
}
/* Write the blocks, walking the map */
while (currBlock <= endBlock) {
size_t to_write = MIN(targetSize, volHeader->blockSize);
ssize_t written;
off_t offset = currBlock * volHeader->blockSize;
/* move map to next block */
mPtr = fmap_need_off_once(*ctx->fmap, offset, volHeader->blockSize);
if (!mPtr) {
cli_errmsg("hfsplus_dumpfile: map error\n");
ret = CL_EMAP;
break;
}
written = cli_writen(ofd, mPtr, to_write);
if ((size_t)written != to_write) {
cli_errmsg("hfsplus_dumpfile: write error\n");
ret = CL_EWRITE;
break;
}
targetSize -= to_write;
outputSize += to_write;
currBlock++;
if (targetSize == 0) {
cli_dbgmsg("hfsplus_dumpfile: all data written\n");
break;
}
if (outputBlocks >= fork->totalBlocks) {
cli_dbgmsg("hfsplus_dumpfile: output all blocks, remaining size " STDu64 "\n", targetSize);
break;
}
}
/* Finished the extent, move to next */
ext++;
} while (ret == CL_CLEAN);
/* if successful so far, scan the output */
if (ret == CL_CLEAN) {
ret = cli_magic_scandesc(ofd, tmpname, ctx);
}
if (ofd >= 0) {
close(ofd);
}
if (!ctx->engine->keeptmp) {
if (cli_unlink(tmpname)) {
ret = CL_EUNLINK;
}
}
free(tmpname);
return ret;
}
/* Calculate true node limit for catalogFile */
static int hfsplus_validate_catalog(cli_ctx *ctx, hfsPlusVolumeHeader *volHeader, hfsHeaderRecord *catHeader)
{
hfsPlusForkData *catFork;
UNUSEDPARAM(ctx);
catFork = &(volHeader->catalogFile);
if (catFork->totalBlocks >= volHeader->totalBlocks) {
cli_dbgmsg("hfsplus_getnodelimit: catFork totalBlocks too large!\n");
return CL_EFORMAT;
}
if (catFork->logicalSize > (catFork->totalBlocks * volHeader->blockSize)) {
cli_dbgmsg("hfsplus_getnodelimit: catFork logicalSize too large!\n");
return CL_EFORMAT;
}
if (catFork->logicalSize < (catHeader->totalNodes * catHeader->nodeSize)) {
cli_dbgmsg("hfsplus_getnodelimit: too many nodes for catFile\n");
return CL_EFORMAT;
}
return CL_CLEAN;
}
/* Fetch a node's contents into the buffer */
static int hfsplus_fetch_node (cli_ctx *ctx, hfsPlusVolumeHeader *volHeader, hfsHeaderRecord *catHeader,
hfsHeaderRecord *extHeader, uint32_t node, uint8_t *buff)
{
int foundBlock = 0;
uint64_t catalogOffset;
uint32_t fetchBlock, fetchStart;
uint32_t extentNum = 0, realFileBlock;
size_t fileOffset = 0;
hfsPlusForkData *catFork;
UNUSEDPARAM(extHeader);
/* Make sure node is in range */
if (node >= catHeader->totalNodes) {
cli_dbgmsg("hfsplus_fetch_node: invalid node number " STDu32 "\n", node);
return CL_EFORMAT;
}
catFork = &(volHeader->catalogFile);
/* Do we need one block or more? */
if (catHeader->nodeSize <= volHeader->blockSize) {
/* Need one block */
/* First, calculate the node's offset within the catalog */
catalogOffset = (uint64_t)node * catHeader->nodeSize;
/* Determine which block of the catalog we need */
fetchBlock = (uint32_t) (catalogOffset / volHeader->blockSize);
fetchStart = (uint32_t) (catalogOffset % volHeader->blockSize);
cli_dbgmsg("hfsplus_fetch_node: need catalog block " STDu32 "\n", fetchBlock);
if (fetchBlock >= catFork->totalBlocks) {
cli_dbgmsg("hfsplus_fetch_node: block number invalid!\n");
return CL_EFORMAT;
}
/* Find which extent has that block */
for (extentNum = 0; extentNum < 8; extentNum++) {
hfsPlusExtentDescriptor *currExt = &(catFork->extents[extentNum]);
/* Beware empty extent */
if ((currExt->startBlock == 0) || (currExt->blockCount == 0)) {
cli_dbgmsg("hfsplus_fetch_node: extent " STDu32 " empty!\n", extentNum);
return CL_EFORMAT;
}
/* Beware too long extent */
if ((currExt->startBlock & 0x10000000) && (currExt->blockCount & 0x10000000)) {
cli_dbgmsg("hfsplus_fetch_node: extent " STDu32 " illegal!\n", extentNum);
return CL_EFORMAT;
}
/* Check if block found in current extent */
if (fetchBlock < currExt->blockCount) {
cli_dbgmsg("hfsplus_fetch_node: found block in extent " STDu32 "\n", extentNum);
realFileBlock = currExt->startBlock + fetchBlock;
foundBlock = 1;
break;
}
else {
cli_dbgmsg("hfsplus_fetch_node: not in extent " STDu32 "\n", extentNum);
fetchBlock -= currExt->blockCount;
}
}
if (foundBlock == 0) {
cli_dbgmsg("hfsplus_fetch_node: not in first 8 extents\n");
cli_dbgmsg("hfsplus_fetch_node: finding this node requires extent overflow support\n");
return CL_EFORMAT;
}
/* Block found */
if (realFileBlock >= volHeader->totalBlocks) {
cli_dbgmsg("hfsplus_fetch_node: block past end of volume\n");
return CL_EFORMAT;
}
fileOffset = realFileBlock * volHeader->blockSize;
}
else {
/* Need more than one block for this node */
cli_dbgmsg("hfsplus_fetch_node: nodesize bigger than blocksize, is this allowed?\n");
return CL_EFORMAT;
}
if (fileOffset) {
if (fmap_readn(*ctx->fmap, buff, fileOffset, catHeader->nodeSize) != catHeader->nodeSize) {
cli_dbgmsg("hfsplus_fetch_node: not all bytes read\n");
return CL_EFORMAT;
}
}
else {
cli_dbgmsg("hfsplus_fetch_node: nodesize bigger than blocksize, is this allowed?\n");
return CL_EFORMAT;
}
return CL_CLEAN;
}
/* Given the catalog and other details, scan all the volume contents */
static int hfsplus_walk_catalog(cli_ctx *ctx, hfsPlusVolumeHeader *volHeader, hfsHeaderRecord *catHeader,
hfsHeaderRecord *extHeader, const char *dirname)
{
int ret = CL_CLEAN;
unsigned int has_alerts = 0;
uint32_t thisNode, nodeLimit, nodesScanned = 0;
uint16_t nodeSize, recordNum, topOfOffsets;
uint16_t distance, recordStart, nextDist, nextStart;
uint8_t *nodeBuf = NULL;
hfsPlusForkData *catFork;
catFork = &(volHeader->catalogFile);
nodeLimit = MIN(catHeader->totalNodes, HFSPLUS_NODE_LIMIT);
thisNode = catHeader->firstLeafNode;
nodeSize = catHeader->nodeSize;
/* Need to buffer current node, map will keep moving */
nodeBuf = cli_malloc(nodeSize);
if (!nodeBuf) {
cli_dbgmsg("hfsplus_walk_catalog: failed to acquire node buffer, "
"size " STDu32 "\n", nodeSize);
return CL_EMEM;
}
/* Walk catalog leaf nodes, and scan contents of each */
/* Because we want to scan them all, the index nodes add no value */
while (ret == CL_CLEAN) {
hfsNodeDescriptor nodeDesc;
if (thisNode == 0) {
cli_dbgmsg("hfsplus_walk_catalog: reached end of leaf nodes.\n");
break;
}
if (nodesScanned++ > nodeLimit) {
cli_dbgmsg("hfsplus_walk_catalog: node scan limit reached.\n");
break;
}
/* fetch node into buffer */
ret = hfsplus_fetch_node(ctx, volHeader, catHeader, extHeader, thisNode, nodeBuf);
if (ret != CL_CLEAN) {
cli_dbgmsg("hfsplus_walk_catalog: node fetch failed.\n");
break;
}
memcpy(&nodeDesc, nodeBuf, 14);
/* convert and validate node */
nodedescriptor_to_host(&nodeDesc);
nodedescriptor_print("leaf node", &nodeDesc);
if ((nodeDesc.kind != HFS_NODEKIND_LEAF) || (nodeDesc.height != 1)) {
cli_dbgmsg("hfsplus_walk_catalog: invalid leaf node!\n");
ret = CL_EFORMAT;
break;
}
if ((nodeSize / 4) < nodeDesc.numRecords) {
cli_dbgmsg("hfsplus_walk_catalog: too many leaf records for one node!\n");
ret = CL_EFORMAT;
break;
}
/* Walk this node's records and scan */
distance = nodeSize;
recordStart = 14; /* 1st record can be after end of node descriptor */
/* offsets take 1 u16 per at the end of the node, along with an empty space offset */
topOfOffsets = nodeSize - (nodeDesc.numRecords * 2) - 2;
for (recordNum = 0; recordNum < nodeDesc.numRecords; recordNum++) {
uint16_t keylen;
int16_t rectype;
hfsPlusCatalogFile fileRec;
/* Locate next record */
nextDist = nodeSize - (recordNum * 2) - 2;
nextStart = nodeBuf[nextDist] * 0x100 + nodeBuf[nextDist+1];
/* Check record location */
if ((nextStart > topOfOffsets-1) || (nextStart < recordStart)) {
cli_dbgmsg("hfsplus_walk_catalog: bad record location %x for %u!\n", nextStart, recordNum);
ret = CL_EFORMAT;
break;
}
distance = nextDist;
recordStart = nextStart;
/* Get record key length */
keylen = nodeBuf[recordStart] * 0x100 + nodeBuf[recordStart+1];
keylen += keylen % 2; /* pad 1 byte if required to make 2-byte align */
/* Validate keylen */
if (recordStart + keylen + 4 >= topOfOffsets) {
cli_dbgmsg("hfsplus_walk_catalog: key too long for location %x for %u!\n",
nextStart, recordNum);
ret = CL_EFORMAT;
break;
}
/* Copy type (after key, which is after keylength field) */
memcpy(&rectype, &(nodeBuf[recordStart+keylen+2]), 2);
rectype = be16_to_host(rectype);
cli_dbgmsg("hfsplus_walk_catalog: record %u nextStart %x keylen %u type %d\n",
recordNum, nextStart, keylen, rectype);
/* Non-file records are not needed */
if (rectype != HFSPLUS_RECTYPE_FILE) {
continue;
}
/* Check file record location */
if (recordStart+keylen+2+sizeof(hfsPlusCatalogFile) >= topOfOffsets) {
cli_dbgmsg("hfsplus_walk_catalog: not enough bytes for file record!\n");
ret = CL_EFORMAT;
break;
}
memcpy(&fileRec, &(nodeBuf[recordStart+keylen+2]), sizeof(hfsPlusCatalogFile));
/* Only scan files */
fileRec.permissions.fileMode = be16_to_host(fileRec.permissions.fileMode);
if ((fileRec.permissions.fileMode & HFS_MODE_TYPEMASK) == HFS_MODE_FILE) {
/* Convert forks and scan */
forkdata_to_host(&(fileRec.dataFork));
forkdata_print("data fork:", &(fileRec.dataFork));
if (fileRec.dataFork.logicalSize) {
ret = hfsplus_scanfile(ctx, volHeader, extHeader, &(fileRec.dataFork), dirname);
}
/* Check return code */
if (ret == CL_VIRUS) {
has_alerts = 1;
if (SCAN_ALLMATCHES) {
/* Continue scanning in SCAN_ALLMATCHES mode */
cli_dbgmsg("hfsplus_walk_catalog: data fork alert, continuing");
ret = CL_CLEAN;
}
}
if (ret != CL_CLEAN) {
cli_dbgmsg("hfsplus_walk_catalog: data fork retcode %d\n", ret);
break;
}
/* Scan resource fork */
forkdata_to_host(&(fileRec.resourceFork));
forkdata_print("resource fork:", &(fileRec.resourceFork));
if (fileRec.resourceFork.logicalSize) {
ret = hfsplus_scanfile(ctx, volHeader, extHeader, &(fileRec.resourceFork), dirname);
}
/* Check return code */
if (ret == CL_VIRUS) {
has_alerts = 1;
if (SCAN_ALLMATCHES) {
/* Continue scanning in SCAN_ALLMATCHES mode */
cli_dbgmsg("hfsplus_walk_catalog: resource fork alert, continuing");
ret = CL_CLEAN;
}
}
if (ret != CL_CLEAN) {
cli_dbgmsg("hfsplus_walk_catalog: resource fork retcode %d", ret);
break;
}
}
else {
cli_dbgmsg("hfsplus_walk_catalog: record mode %o is not File\n", fileRec.permissions.fileMode);
}
}
/* if return code, exit loop, message already logged */
if (ret != CL_CLEAN) {
break;
}
/* After that, proceed to next node */
if (thisNode == nodeDesc.fLink) {
/* Future heuristic */
cli_warnmsg("hfsplus_walk_catalog: simple cycle detected!\n");
ret = CL_EFORMAT;
break;
}
else {
thisNode = nodeDesc.fLink;
}
}
free(nodeBuf);
if (has_alerts) {
ret = CL_VIRUS;
}
return ret;
}
/* Base scan function for scanning HFS+ or HFSX partitions */
int cli_scanhfsplus(cli_ctx *ctx)
{
char *targetdir = NULL;
int ret = CL_CLEAN;
hfsPlusVolumeHeader *volHeader = NULL;
hfsNodeDescriptor catFileDesc;
hfsHeaderRecord catFileHeader;
hfsNodeDescriptor extentFileDesc;
hfsHeaderRecord extentFileHeader;
if (!ctx || !ctx->fmap) {
cli_errmsg("cli_scanhfsplus: Invalid context\n");
return CL_ENULLARG;
}
cli_dbgmsg("cli_scanhfsplus: scanning partition content\n");
/* first, read volume header contents */
ret = hfsplus_volumeheader(ctx, &volHeader);
if (ret != CL_CLEAN) {
goto freeHeader;
}
/*
cli_dbgmsg("sizeof(hfsUniStr255) is %lu\n", sizeof(hfsUniStr255));
cli_dbgmsg("sizeof(hfsPlusBSDInfo) is %lu\n", sizeof(hfsPlusBSDInfo));
cli_dbgmsg("sizeof(hfsPlusExtentDescriptor) is %lu\n", sizeof(hfsPlusExtentDescriptor));
cli_dbgmsg("sizeof(hfsPlusExtentRecord) is %lu\n", sizeof(hfsPlusExtentRecord));
cli_dbgmsg("sizeof(hfsPlusForkData) is %lu\n", sizeof(hfsPlusForkData));
cli_dbgmsg("sizeof(hfsPlusVolumeHeader) is %lu\n", sizeof(hfsPlusVolumeHeader));
cli_dbgmsg("sizeof(hfsNodeDescriptor) is %lu\n", sizeof(hfsNodeDescriptor));
*/
/* Get root node (header node) of extent overflow file */
ret = hfsplus_readheader(ctx, volHeader, &extentFileDesc, &extentFileHeader, HFS_FILETREE_EXTENTS, "extentFile");
if (ret != CL_CLEAN) {
goto freeHeader;
}
/* Get root node (header node) of catalog file */
ret = hfsplus_readheader(ctx, volHeader, &catFileDesc, &catFileHeader, HFS_FILETREE_CATALOG, "catalogFile");
if (ret != CL_CLEAN) {
goto freeHeader;
}
/* Create temp folder for contents */
if (!(targetdir = cli_gentemp(ctx->engine->tmpdir))) {
cli_errmsg("cli_scandmg: cli_gentemp failed\n");
ret = CL_ETMPDIR;
goto freeHeader;
}
if (mkdir(targetdir, 0700)) {
cli_errmsg("cli_scandmg: Cannot create temporary directory %s\n", targetdir);
ret = CL_ETMPDIR;
goto freeDirname;
}
cli_dbgmsg("cli_scandmg: Extracting into %s\n", targetdir);
/* Can build and scan catalog file if we want ***
ret = hfsplus_scanfile(ctx, volHeader, &extentFileHeader, &(volHeader->catalogFile), targetdir);
*/
if (ret == CL_CLEAN) {
ret = hfsplus_validate_catalog(ctx, volHeader, &catFileHeader);
if (ret == CL_CLEAN) {
cli_dbgmsg("cli_scandmg: validation successful\n");
}
else {
cli_dbgmsg("cli_scandmg: validation returned %d : %s\n", ret, cl_strerror(ret));
}
}
/* Walk through catalog to identify files to scan */
if (ret == CL_CLEAN) {
ret = hfsplus_walk_catalog(ctx, volHeader, &catFileHeader, &extentFileHeader, targetdir);
cli_dbgmsg("cli_scandmg: walk catalog finished\n");
}
/* Clean up extracted content, if needed */
if (!ctx->engine->keeptmp) {
cli_rmdirs(targetdir);
}
freeDirname:
free(targetdir);
freeHeader:
free(volHeader);
return ret;
}