/*
* integrity.c
*
- * WIM files can optionally contain an array of SHA1 message digests at the end,
- * one digest for each 1 MB of the file. This file implements the checking of
- * the digests, and the writing of the digests for new WIM files.
+ * WIM files can optionally contain a table of SHA1 message digests at the end,
+ * one digest for each chunk of the file of some specified size (often 10 MB).
+ * This file implements the checking and writing of this table.
*/
/*
- * Copyright (C) 2012 Eric Biggers
+ * Copyright (C) 2012, 2013 Eric Biggers
*
* This file is part of wimlib, a library for working with WIM files.
*
*/
#include "wimlib_internal.h"
-#include "io.h"
+#include "buffer_io.h"
#include "sha1.h"
/* Size, in bytes, of each SHA1-summed chunk, when wimlib writes integrity
/*
- * Reads the integrity table from a WIM file.
+ * read_integrity_table: - Reads the integrity table from a WIM file.
*
* @res_entry:
* The resource entry that specifies the location of the integrity table.
u64 expected_size;
u64 expected_num_entries;
- if (res_entry->original_size < 12) {
- ERROR("Integrity table is too short (expected at least 12 bytes)");
- ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ if (resource_is_compressed(res_entry)) {
+ ERROR("Didn't expect a compressed integrity table");
+ return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
}
- if (res_entry->flags & WIM_RESHDR_FLAG_COMPRESSED) {
- ERROR("Didn't expect a compressed integrity table");
- ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ if (res_entry->size < 8 || res_entry->size > 0xffffffff) {
+ ERROR("Integrity table resource header is invalid");
+ return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
}
/* Read the integrity table into memory. */
- if ((sizeof(size_t) < sizeof(u64)
- && res_entry->size > ~(size_t)0)
- || ((table = MALLOC(res_entry->size)) == NULL))
- {
- ERROR("Out of memory (needed %zu bytes for integrity table)",
- (size_t)res_entry->size);
- ret = WIMLIB_ERR_NOMEM;
- goto out;
+ if ((table = MALLOC(res_entry->size)) == NULL) {
+ ERROR("Can't allocate %"PRIu64" bytes for integrity table",
+ (u64)res_entry->size);
+ return WIMLIB_ERR_NOMEM;
}
ret = read_uncompressed_resource(fp, res_entry->offset,
res_entry->size, (void*)table);
if (ret != 0) {
- ERROR("Failed to read integrity table (size = %"PRIu64", "
+ ERROR("Failed to read integrity table (size = %u, "
" offset = %"PRIu64")",
- (u64)res_entry->size, res_entry->offset);
+ (unsigned)res_entry->size, res_entry->offset);
goto out;
}
if (table->size != res_entry->size) {
ERROR("Inconsistent integrity table sizes: Table header says "
- "%u bytes but resource entry says %"PRIu64" bytes",
- table->size, (u64)res_entry->size);
+ "%u bytes but resource entry says %u bytes",
+ table->size, (unsigned)res_entry->size);
ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
goto out;
}
expected_num_entries = DIV_ROUND_UP(num_checked_bytes, table->chunk_size);
if (table->num_entries != expected_num_entries) {
- ERROR("%"PRIu64" entries would be required to checksum "
- "the %"PRIu64" bytes from the end of the header to the",
+ ERROR("%"PRIu64" integrity table entries would be required "
+ "to checksum the %"PRIu64" bytes from the end of the "
+ "header to the",
expected_num_entries, num_checked_bytes);
ERROR("end of the lookup table with a chunk size of %u, but "
"there were only %u entries",
}
/*
+ * calculate_integrity_table():
+ *
* Calculates an integrity table for the data in a file beginning at offset 208
* (WIM_HEADER_DISK_SIZE).
*
* Offset of byte after the last byte to be checked.
*
* @old_table:
- * If non-NULL, a pointer to the table containing previously contained
+ * If non-NULL, a pointer to the table containing the previously calculated
* integrity data for a prefix of this file.
*
* @old_check_end:
/* If an old table is provided, set the chunk size to be compatible with
* the old chunk size, unless the old chunk size was weird. */
if (old_table != NULL) {
- if (old_table->chunk_size < INTEGRITY_MIN_CHUNK_SIZE ||
+ if (old_table->num_entries == 0 ||
+ old_table->chunk_size < INTEGRITY_MIN_CHUNK_SIZE ||
old_table->chunk_size > INTEGRITY_MAX_CHUNK_SIZE)
old_table = NULL;
else
}
/*
+ * write_integrity_table():
+ *
* Writes a WIM integrity table (a list of SHA1 message digests of raw 10 MiB
* chunks of the file).
*
wimlib_assert(old_lookup_table_end <= new_lookup_table_end);
cur_offset = ftello(fp);
- if (cur_offset == -1) {
- ERROR_WITH_ERRNO("Failed to get offset in WIM");
+ if (cur_offset == -1)
return WIMLIB_ERR_WRITE;
- }
if (integrity_res_entry->offset == 0 || old_lookup_table_end == 0) {
old_table = NULL;
}
/*
+ * verify_integrity():
+ *
* Checks a WIM for consistency with the integrity table.
*
* @fp:
/*
+ * check_wim_integrity():
+ *
* Verifies the integrity of the WIM by making sure the SHA1 message digests of
* ~10 MiB chunks of the WIM match up with the values given in the integrity
- * tabel.
+ * table.
*
* @w:
* The WIM, opened for reading, and with the header already read.