X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmetadata_resource.c;h=109b0d32ca2499d308c0a68d8d13d1f1865211f8;hp=2f7dfeb6e729ce0ae3dd4c0f7a59ca05f9f96e49;hb=fa023959402e041d71295d5f2812174c55a0cc64;hpb=ac6edfd02c612da68a1b9a1b32ae64c95a87fbb1 diff --git a/src/metadata_resource.c b/src/metadata_resource.c index 2f7dfeb6..109b0d32 100644 --- a/src/metadata_resource.c +++ b/src/metadata_resource.c @@ -20,9 +20,17 @@ * wimlib; if not, see http://www.gnu.org/licenses/. */ -#include "wimlib_internal.h" -#include "dentry.h" -#include "lookup_table.h" +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "wimlib/dentry.h" +#include "wimlib/error.h" +#include "wimlib/file_io.h" +#include "wimlib/lookup_table.h" +#include "wimlib/metadata.h" +#include "wimlib/resource.h" +#include "wimlib/security.h" /* * Reads a metadata resource for an image in the WIM file. The metadata @@ -44,14 +52,14 @@ * Returns: Zero on success, nonzero on failure. */ int -read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) +read_metadata_resource(WIMStruct *wim, struct wim_image_metadata *imd) { u8 *buf; - u32 dentry_offset; int ret; - struct wim_dentry *dentry; + struct wim_dentry *root; const struct wim_lookup_table_entry *metadata_lte; u64 metadata_len; + u8 hash[SHA1_HASH_SIZE]; metadata_lte = imd->metadata_lte; metadata_len = wim_resource_size(metadata_lte); @@ -65,7 +73,7 @@ read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) /* There is no way the metadata resource could possibly be less than (8 * + WIM_DENTRY_DISK_SIZE) bytes, where the 8 is for security data (with * no security descriptors) and WIM_DENTRY_DISK_SIZE is for the root - * dentry. */ + * entry. */ if (metadata_len < 8 + WIM_DENTRY_DISK_SIZE) { ERROR("Expected at least %u bytes for the metadata resource", 8 + WIM_DENTRY_DISK_SIZE); @@ -92,6 +100,13 @@ read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) if (ret) goto out_free_buf; + sha1_buffer(buf, metadata_len, hash); + if (!hashes_equal(metadata_lte->hash, hash)) { + ERROR("Metadata resource is corrupted (invalid SHA-1 message digest)!"); + ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; + goto out_free_buf; + } + DEBUG("Finished reading metadata resource into memory."); /* The root directory entry starts after security data, aligned on an @@ -102,78 +117,75 @@ read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) * the offset of the root dentry. * * Here we read the security data into a wim_security_data structure, - * and if successful, go ahead and calculate the offset in the metadata - * resource of the root dentry. */ + * which takes case of rouding total_length. If successful, go ahead + * and calculate the offset in the metadata resource of the root dentry. + * */ - wimlib_assert(imd->security_data == NULL); - ret = read_security_data(buf, metadata_len, &imd->security_data); + ret = read_wim_security_data(buf, metadata_len, &imd->security_data); if (ret) goto out_free_buf; - dentry_offset = (imd->security_data->total_length + 7) & ~7; - - if (dentry_offset == 0) { - ERROR("Integer overflow while reading metadata resource"); - ret = WIMLIB_ERR_INVALID_SECURITY_DATA; - goto out_free_security_data; - } - DEBUG("Reading root dentry"); /* Allocate memory for the root dentry and read it into memory */ - dentry = MALLOC(sizeof(struct wim_dentry)); - if (!dentry) { - ERROR("Failed to allocate %zu bytes for root dentry", - sizeof(struct wim_dentry)); + root = MALLOC(sizeof(struct wim_dentry)); + if (!root) { ret = WIMLIB_ERR_NOMEM; goto out_free_security_data; } - ret = read_dentry(buf, metadata_len, dentry_offset, dentry); - - /* This is the root dentry, so set its parent to itself. */ - dentry->parent = dentry; + ret = read_dentry(buf, metadata_len, + imd->security_data->total_length, root); - if (ret == 0 && dentry->length == 0) { - ERROR("Metadata resource cannot begin with end-of-directory entry!"); - ret = WIMLIB_ERR_INVALID_DENTRY; + if (ret == 0 && root->length == 0) { + WARNING("Metadata resource begins with end-of-directory entry " + "(treating as empty image)"); + FREE(root); + root = NULL; + goto out_success; } - if (ret != 0) { - FREE(dentry); + if (ret) { + FREE(root); goto out_free_security_data; } - inode_add_dentry(dentry, dentry->d_inode); + /* This is the root dentry, so set its parent to itself. */ + root->parent = root; + + inode_add_dentry(root, root->d_inode); /* Now read the entire directory entry tree into memory. */ DEBUG("Reading dentry tree"); - ret = read_dentry_tree(buf, metadata_len, dentry); + ret = read_dentry_tree(buf, metadata_len, root); if (ret) goto out_free_dentry_tree; /* Build hash table that maps hard link group IDs to dentry sets */ - ret = dentry_tree_fix_inodes(dentry, &imd->inode_list); + ret = dentry_tree_fix_inodes(root, &imd->inode_list); if (ret) goto out_free_dentry_tree; - if (!w->all_images_verified) { + if (!wim->all_images_verified) { + /* Note: verify_dentry() expects to access imd->security_data, + * so it needs to be set before here. */ DEBUG("Running miscellaneous verifications on the dentry tree"); - for_lookup_table_entry(w->lookup_table, lte_zero_real_refcnt, NULL); - ret = for_dentry_in_tree(dentry, verify_dentry, w); + for_lookup_table_entry(wim->lookup_table, lte_zero_real_refcnt, NULL); + ret = for_dentry_in_tree(root, verify_dentry, wim); if (ret) goto out_free_dentry_tree; } DEBUG("Done reading image metadata"); - imd->root_dentry = dentry; +out_success: + imd->root_dentry = root; INIT_LIST_HEAD(&imd->unhashed_streams); goto out_free_buf; out_free_dentry_tree: - free_dentry_tree(dentry, NULL); + free_dentry_tree(root, wim->lookup_table); out_free_security_data: - free_security_data(imd->security_data); + free_wim_security_data(imd->security_data); imd->security_data = NULL; out_free_buf: FREE(buf); @@ -186,7 +198,7 @@ recalculate_security_data_length(struct wim_security_data *sd) u32 total_length = sizeof(u64) * sd->num_entries + 2 * sizeof(u32); for (u32 i = 0; i < sd->num_entries; i++) total_length += sd->sizes[i]; - sd->total_length = total_length; + sd->total_length = (total_length + 7) & ~7; } /* Like write_wim_resource(), but the resource is specified by a buffer of @@ -272,7 +284,7 @@ write_metadata_resource(WIMStruct *w) } /* Write the security data into the resource buffer */ - p = write_security_data(sd, buf); + p = write_wim_security_data(sd, buf); /* Write the dentry tree into the resource buffer */ p = write_dentry_tree(root, p);