/*
* 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.
*
* along with wimlib; if not, see http://www.gnu.org/licenses/.
*/
-#include "wimlib_internal.h"
-#include "io.h"
-#include "sha1.h"
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "wimlib/assert.h"
+#include "wimlib/endianness.h"
+#include "wimlib/error.h"
+#include "wimlib/file_io.h"
+#include "wimlib/integrity.h"
+#include "wimlib/resource.h"
+#include "wimlib/sha1.h"
+#include "wimlib/wim.h"
/* Size, in bytes, of each SHA1-summed chunk, when wimlib writes integrity
* information. */
#define INTEGRITY_CHUNK_SIZE 10485760
-/*
- * Verifies the integrity of a WIM.
- *
- * @fp: FILE* of the WIM, currently positioned at the end of the header.
- * @num_bytes: Number of bytes to verify the integrity of.
- * @chunk_size: Chunk size per SHA1 message digest.
- * @sha1sums: Array of SHA1 message digests; 20 bytes each, one per chunk.
- * @show_progress: Nonzero if the percent complete is to be printed after every
- * chunk.
- * @status: On success, set to WIM_INTEGRITY_OK or WIM_INTEGRITY_NOT_OK
- * based on whether the WIM is intact or not.
- */
-static int verify_integrity(FILE *fp, u64 num_bytes, u32 chunk_size,
- const u8 *sha1sums, int show_progress,
- int *status)
+/* Only use a different chunk size for compatiblity with an existing integrity
+ * table if the chunk size is between these two numbers. */
+#define INTEGRITY_MIN_CHUNK_SIZE 4096
+#define INTEGRITY_MAX_CHUNK_SIZE 134217728
+
+struct integrity_table {
+ u32 size;
+ u32 num_entries;
+ u32 chunk_size;
+ u8 sha1sums[][20];
+} _packed_attribute;
+
+static int
+calculate_chunk_sha1(int in_fd, size_t this_chunk_size,
+ off_t offset, u8 sha1_md[])
{
- u8 *chunk_buf;
- u8 resblock[SHA1_HASH_SIZE];
- u64 bytes_remaining;
+ u8 buf[BUFFER_SIZE];
+ SHA_CTX ctx;
+ size_t bytes_remaining;
size_t bytes_to_read;
- uint percent_done;
- int ret;
+ size_t bytes_read;
- chunk_buf = MALLOC(chunk_size);
- if (!chunk_buf) {
- ERROR("Failed to allocate %u byte buffer for integrity chunks",
- chunk_size);
- return WIMLIB_ERR_NOMEM;
- }
- bytes_remaining = num_bytes;
- while (bytes_remaining != 0) {
- if (show_progress) {
- percent_done = (num_bytes - bytes_remaining) * 100 /
- num_bytes;
- printf("Verifying integrity of WIM (%"PRIu64" bytes "
- "remaining, %u%% done) \r",
- bytes_remaining, percent_done);
- fflush(stdout);
- }
- bytes_to_read = min(chunk_size, bytes_remaining);
- if (fread(chunk_buf, 1, bytes_to_read, fp) != bytes_to_read) {
- if (feof(fp)) {
- ERROR("Unexpected EOF while verifying "
- "integrity of WIM");
- } else {
- ERROR_WITH_ERRNO("File stream error while "
- "verifying integrity of WIM");
- }
- ret = WIMLIB_ERR_READ;
- goto verify_integrity_error;
- }
- sha1_buffer(chunk_buf, bytes_to_read, resblock);
- if (!hashes_equal(resblock, sha1sums)) {
- *status = WIM_INTEGRITY_NOT_OK;
- goto verify_integrity_done;
+ bytes_remaining = this_chunk_size;
+ sha1_init(&ctx);
+ do {
+ bytes_to_read = min(bytes_remaining, sizeof(buf));
+ bytes_read = full_pread(in_fd, buf, bytes_to_read, offset);
+ if (bytes_read != bytes_to_read) {
+ ERROR_WITH_ERRNO("Read error while calculating "
+ "integrity checksums");
+ return WIMLIB_ERR_READ;
}
- sha1sums += SHA1_HASH_SIZE;
- bytes_remaining -= bytes_to_read;
- }
- *status = WIM_INTEGRITY_OK;
-verify_integrity_done:
- ret = 0;
-verify_integrity_error:
- FREE(chunk_buf);
- if (show_progress)
- putchar('\n');
- return ret;
+ sha1_update(&ctx, buf, bytes_read);
+ bytes_remaining -= bytes_read;
+ offset += bytes_read;
+ } while (bytes_remaining);
+ sha1_final(sha1_md, &ctx);
+ return 0;
}
+
/*
- * Verifies the integrity of the WIM.
+ * read_integrity_table: - Reads the integrity table from a WIM file.
+ *
+ * @res_entry:
+ * The resource entry that specifies the location of the integrity table.
+ * The integrity table must exist (i.e. res_entry->offset must not be 0).
+ *
+ * @in_fd:
+ * File descriptor to the WIM file, opened for reading.
+ *
+ * @num_checked_bytes:
+ * Number of bytes of data that should be checked by the integrity table.
*
- * @show_progress: Nonzero if the percent complete is to be printed after every
- * chunk.
- * @status: On success, set to WIM_INTEGRITY_OK, WIM_INTEGRITY_NOT_OK,
- * or WIM_INTEGRITY_NONEXISTENT.
+ * @table ret:
+ * On success, a pointer to an in-memory structure containing the integrity
+ * information is written to this location.
*
- * Returns: 0, WIMLIB_ERR_INVALID_INTEGRITY_TABLE, WIMLIB_ERR_NOMEM, or
- * WIMLIB_ERR_READ. If nonzero, the boolean pointed to by @ok is not changed.
+ * Returns 0 on success; nonzero on failure. The possible error codes are:
+ *
+ * * WIMLIB_ERR_INVALID_INTEGRITY_TABLE: The integrity table is invalid.
+ * * WIMLIB_ERR_NOMEM: Could not allocate memory to store the integrity
+ * data.
+ * * WIMLIB_ERR_READ: Could not read the integrity data from the WIM file.
*/
-int check_wim_integrity(WIMStruct *w, int show_progress, int *status)
+static int
+read_integrity_table(const struct resource_entry *res_entry,
+ int in_fd,
+ u64 num_checked_bytes,
+ struct integrity_table **table_ret)
{
-
- struct resource_entry *res_entry;
- u8 *buf = NULL;
+ struct integrity_table *table;
int ret;
- u32 integrity_table_size;
- u32 num_entries;
- u32 chunk_size;
- const u8 *p;
u64 expected_size;
- u64 end_lookup_table_offset;
- u64 bytes_to_check;
u64 expected_num_entries;
- res_entry = &w->hdr.integrity;
- if (res_entry->size == 0) {
- DEBUG("No integrity information.");
- *status = WIM_INTEGRITY_NONEXISTENT;
- return 0;
- }
- if (res_entry->original_size < 12) {
- ERROR("Integrity table is too short");
+ 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");
+
+ 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->original_size > ~(size_t)0)
- || ((buf = MALLOC(res_entry->original_size)) == NULL))
- {
- ERROR("Out of memory (needed %zu bytes for integrity table)",
- (size_t)res_entry->original_size);
- ret = WIMLIB_ERR_NOMEM;
- goto out;
- }
- ret = read_uncompressed_resource(w->fp, res_entry->offset,
- res_entry->original_size, buf);
- if (ret != 0) {
- ERROR("Failed to read integrity table (size = %"PRIu64", "
- "original_size = %"PRIu64", offset = "
- "%"PRIu64")",
- (u64)res_entry->size, res_entry->original_size,
- res_entry->offset);
- goto out;
+ table = MALLOC((size_t)res_entry->size);
+ if (table == NULL) {
+ ERROR("Can't allocate %zu bytes for integrity table",
+ (size_t)res_entry->size);
+ return WIMLIB_ERR_NOMEM;
}
- p = get_u32(buf, &integrity_table_size);
- p = get_u32(p, &num_entries);
- p = get_u32(p, &chunk_size);
+ if (full_pread(in_fd, table, res_entry->size,
+ res_entry->offset) != res_entry->size)
+ {
+ ERROR("Failed to read integrity table (size = %zu, "
+ " offset = %"PRIu64")",
+ (size_t)res_entry->size, res_entry->offset);
+ ret = WIMLIB_ERR_READ;
+ goto out_free_table;
+ }
- /* p now points to the array of SHA1 message digests for the WIM. */
+ table->size = le32_to_cpu(table->size);
+ table->num_entries = le32_to_cpu(table->num_entries);
+ table->chunk_size = le32_to_cpu(table->chunk_size);
- /* Make sure the integrity table is the right size. */
- if (integrity_table_size != res_entry->original_size) {
- ERROR("Inconsistent integrity table sizes: header says %u "
- "bytes but resource entry says "
- "%"PRIu64" bytes",
- integrity_table_size, res_entry->original_size);
+ if (table->size != res_entry->size) {
+ ERROR("Inconsistent integrity table sizes: Table header says "
+ "%u bytes but resource entry says %u bytes",
+ table->size, (unsigned)res_entry->size);
ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ goto out_free_table;
}
- DEBUG("integrity_table_size = %u, num_entries = %u, chunk_size = %u",
- integrity_table_size, num_entries, chunk_size);
+ DEBUG("table->size = %u, table->num_entries = %u, "
+ "table->chunk_size = %u",
+ table->size, table->num_entries, table->chunk_size);
+ expected_size = (u64)table->num_entries * SHA1_HASH_SIZE + 12;
- expected_size = num_entries * SHA1_HASH_SIZE + 12;
-
- if (integrity_table_size != expected_size) {
+ if (table->size != expected_size) {
ERROR("Integrity table is %u bytes, but expected %"PRIu64" "
"bytes to hold %u entries",
- integrity_table_size, expected_size, num_entries);
+ table->size, expected_size, table->num_entries);
ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ goto out_free_table;
}
- if (chunk_size == 0) {
+ if (table->chunk_size == 0) {
ERROR("Cannot use integrity chunk size of 0");
ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ goto out_free_table;
}
- end_lookup_table_offset = w->hdr.lookup_table_res_entry.offset +
- w->hdr.lookup_table_res_entry.size;
+ expected_num_entries = DIV_ROUND_UP(num_checked_bytes, table->chunk_size);
- if (end_lookup_table_offset < WIM_HEADER_DISK_SIZE) {
- ERROR("WIM lookup table ends before WIM header ends???");
- ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
- }
-
- bytes_to_check = end_lookup_table_offset - WIM_HEADER_DISK_SIZE;
-
- expected_num_entries = (bytes_to_check + chunk_size - 1) / chunk_size;
-
- if (num_entries != expected_num_entries) {
- ERROR("%"PRIu64" entries would be required to checksum "
- "the %"PRIu64" bytes from the end of the header to the",
- expected_num_entries, bytes_to_check);
+ if (table->num_entries != expected_num_entries) {
+ 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", chunk_size, num_entries);
+ "there were only %u entries",
+ table->chunk_size, table->num_entries);
ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
- goto out;
+ goto out_free_table;
}
-
- /* The integrity checking starts after the header, so seek to the offset
- * in the WIM after the header. */
-
- if (fseeko(w->fp, WIM_HEADER_DISK_SIZE, SEEK_SET) != 0) {
- ERROR_WITH_ERRNO("Failed to seek to byte %u of WIM to check "
- "integrity", WIM_HEADER_DISK_SIZE);
- ret = WIMLIB_ERR_READ;
- goto out;
- }
- /* call verify_integrity(), which does the actual checking of the SHA1
- * message digests. */
- ret = verify_integrity(w->fp, bytes_to_check, chunk_size, p,
- show_progress, status);
+ *table_ret = table;
+ ret = 0;
+ goto out;
+out_free_table:
+ FREE(table);
out:
- FREE(buf);
return ret;
}
/*
- * Writes integrity information to the output stream for a WIM file being
- * written.
+ * calculate_integrity_table():
+ *
+ * Calculates an integrity table for the data in a file beginning at offset 208
+ * (WIM_HEADER_DISK_SIZE).
+ *
+ * @in_fd:
+ * File descriptor for the file to be checked, opened for reading. Does
+ * not need to be at any specific location in the file.
+ *
+ * @new_check_end:
+ * Offset of byte after the last byte to be checked.
+ *
+ * @old_table:
+ * If non-NULL, a pointer to the table containing the previously calculated
+ * integrity data for a prefix of this file.
+ *
+ * @old_check_end:
+ * If @old_table is non-NULL, the byte after the last byte that was checked
+ * in the old table. Must be less than or equal to new_check_end.
*
- * @end_header_offset is the offset of the byte after the header, which is the
- * beginning of the region that is checksummed.
+ * @progress_func:
+ * If non-NULL, a progress function that will be called after every
+ * calculated chunk.
*
- * @end_lookup_table_offset is the offset of the byte after the lookup table,
- * which is the end of the region that is checksummed.
+ * @integrity_table_ret:
+ * On success, a pointer to the calculated integrity table is written into
+ * this location.
+ *
+ * Returns 0 on success; nonzero on failure.
*/
-int write_integrity_table(FILE *out, u64 end_header_offset,
- u64 end_lookup_table_offset, int show_progress)
+static int
+calculate_integrity_table(int in_fd,
+ off_t new_check_end,
+ const struct integrity_table *old_table,
+ off_t old_check_end,
+ wimlib_progress_func_t progress_func,
+ struct integrity_table **integrity_table_ret)
{
- u64 bytes_to_check;
- u64 bytes_remaining;
- u8 *buf;
- u8 *p;
- u8 *chunk_buf;
- u32 num_entries;
- u32 integrity_table_size;
- int ret;
-
- DEBUG("Calculating integrity table");
- if (fseeko(out, end_header_offset, SEEK_SET) != 0) {
- ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of WIM to "
- "calculate integrity data", end_header_offset);
- return WIMLIB_ERR_WRITE;
+ int ret;
+ size_t chunk_size = INTEGRITY_CHUNK_SIZE;
+
+ /* 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->num_entries == 0 ||
+ old_table->chunk_size < INTEGRITY_MIN_CHUNK_SIZE ||
+ old_table->chunk_size > INTEGRITY_MAX_CHUNK_SIZE)
+ old_table = NULL;
+ else
+ chunk_size = old_table->chunk_size;
}
- bytes_to_check = end_lookup_table_offset - end_header_offset;
- num_entries = (bytes_to_check + INTEGRITY_CHUNK_SIZE - 1) /
- INTEGRITY_CHUNK_SIZE;
- integrity_table_size = num_entries * SHA1_HASH_SIZE + 3 * sizeof(u32);
- DEBUG("integrity_table_size = %u", integrity_table_size);
+ u64 old_check_bytes = old_check_end - WIM_HEADER_DISK_SIZE;
+ u64 new_check_bytes = new_check_end - WIM_HEADER_DISK_SIZE;
- buf = MALLOC(integrity_table_size);
- if (!buf) {
- ERROR("Failed to allocate %u bytes for integrity table",
- integrity_table_size);
- return WIMLIB_ERR_NOMEM;
- }
+ u32 old_num_chunks = DIV_ROUND_UP(old_check_bytes, chunk_size);
+ u32 new_num_chunks = DIV_ROUND_UP(new_check_bytes, chunk_size);
+
+ size_t old_last_chunk_size = MODULO_NONZERO(old_check_bytes, chunk_size);
+ size_t new_last_chunk_size = MODULO_NONZERO(new_check_bytes, chunk_size);
- p = put_u32(buf, integrity_table_size);
- p = put_u32(p, num_entries);
- p = put_u32(p, INTEGRITY_CHUNK_SIZE);
+ size_t new_table_size = 12 + new_num_chunks * SHA1_HASH_SIZE;
- chunk_buf = MALLOC(INTEGRITY_CHUNK_SIZE);
- if (!chunk_buf) {
- ERROR("Failed to allocate %u bytes for integrity chunk buffer",
- INTEGRITY_CHUNK_SIZE);
- ret = WIMLIB_ERR_NOMEM;
- goto out_free_buf;
+ struct integrity_table *new_table = MALLOC(new_table_size);
+ if (!new_table)
+ return WIMLIB_ERR_NOMEM;
+ new_table->num_entries = new_num_chunks;
+ new_table->size = new_table_size;
+ new_table->chunk_size = chunk_size;
+
+ u64 offset = WIM_HEADER_DISK_SIZE;
+ union wimlib_progress_info progress;
+
+ if (progress_func) {
+ progress.integrity.total_bytes = new_check_bytes;
+ progress.integrity.total_chunks = new_num_chunks;
+ progress.integrity.completed_chunks = 0;
+ progress.integrity.completed_bytes = 0;
+ progress.integrity.chunk_size = chunk_size;
+ progress.integrity.filename = NULL;
+ progress_func(WIMLIB_PROGRESS_MSG_CALC_INTEGRITY,
+ &progress);
}
- bytes_remaining = bytes_to_check;
+ for (u32 i = 0; i < new_num_chunks; i++) {
+ size_t this_chunk_size;
+ if (i == new_num_chunks - 1)
+ this_chunk_size = new_last_chunk_size;
+ else
+ this_chunk_size = chunk_size;
+ if (old_table &&
+ ((this_chunk_size == chunk_size && i < old_num_chunks - 1) ||
+ (i == old_num_chunks - 1 && this_chunk_size == old_last_chunk_size)))
+ {
+ /* Can use SHA1 message digest from old integrity table
+ * */
+ copy_hash(new_table->sha1sums[i], old_table->sha1sums[i]);
+ } else {
+ /* Calculate the SHA1 message digest of this chunk */
+ ret = calculate_chunk_sha1(in_fd, this_chunk_size,
+ offset, new_table->sha1sums[i]);
+ if (ret) {
+ FREE(new_table);
+ return ret;
+ }
+ }
+ offset += this_chunk_size;
+ if (progress_func) {
+ progress.integrity.completed_chunks++;
+ progress.integrity.completed_bytes += this_chunk_size;
+ progress_func(WIMLIB_PROGRESS_MSG_CALC_INTEGRITY,
+ &progress);
+ }
+ }
+ *integrity_table_ret = new_table;
+ return 0;
+}
- DEBUG("Bytes to check = %"PRIu64, bytes_to_check);
+/*
+ * write_integrity_table():
+ *
+ * Writes a WIM integrity table (a list of SHA1 message digests of raw 10 MiB
+ * chunks of the file).
+ *
+ * This function can optionally re-use entries from an older integrity table.
+ * To do this, make @integrity_res_entry point to the resource entry for the
+ * older table (note: this is an input-output parameter), and set
+ * @old_lookup_table_end to the offset of the byte directly following the last
+ * byte checked by the old table. If the old integrity table is invalid or
+ * cannot be read, a warning is printed and the integrity information is
+ * re-calculated.
+ *
+ * @fd:
+ * File descriptor to the WIM file, opened read-write, positioned at the
+ * location at which the integrity table is to be written.
+ *
+ * @integrity_res_entry:
+ * Resource entry which will be set to point to the integrity table on
+ * success. In addition, if @old_lookup_table_end != 0, this initially
+ * must point to the resource entry for the old integrity table for the
+ * WIM.
+ *
+ * @new_lookup_table_end:
+ * The offset of the byte directly following the lookup table in the WIM
+ * being written.
+ *
+ * @old_lookup_table_end:
+ * If nonzero, the offset of the byte directly following the old lookup
+ * table in the WIM.
+ *
+ * @progress_func
+ * If non-NULL, a progress function that will be called after every
+ * calculated chunk.
+ *
+ * Returns:
+ * 0 on success, nonzero on failure. The possible error codes are:
+ * * WIMLIB_ERR_WRITE: Could not write the integrity table.
+ * * WIMLIB_ERR_READ: Could not read a chunk of data that needed
+ * to be checked.
+ */
+int
+write_integrity_table(int fd,
+ struct resource_entry *integrity_res_entry,
+ off_t new_lookup_table_end,
+ off_t old_lookup_table_end,
+ wimlib_progress_func_t progress_func)
+{
+ struct integrity_table *old_table;
+ struct integrity_table *new_table;
+ int ret;
+ off_t cur_offset;
+ u32 new_table_size;
- while (bytes_remaining != 0) {
+ wimlib_assert(old_lookup_table_end <= new_lookup_table_end);
- uint percent_done = (bytes_to_check - bytes_remaining) *
- 100 / bytes_to_check;
+ cur_offset = filedes_offset(fd);
+ if (cur_offset == -1)
+ return WIMLIB_ERR_WRITE;
- if (show_progress) {
- printf("Calculating integrity checksums for WIM "
- "(%"PRIu64" bytes remaining, %u%% "
- "done) \r",
- bytes_remaining, percent_done);
- fflush(stdout);
+ if (integrity_res_entry->offset == 0 || old_lookup_table_end == 0) {
+ old_table = NULL;
+ } else {
+ ret = read_integrity_table(integrity_res_entry, fd,
+ old_lookup_table_end - WIM_HEADER_DISK_SIZE,
+ &old_table);
+ if (ret == WIMLIB_ERR_INVALID_INTEGRITY_TABLE) {
+ WARNING("Old integrity table is invalid! "
+ "Ignoring it");
+ } else if (ret != 0) {
+ WARNING("Can't read old integrity table! "
+ "Ignoring it");
}
+ }
+ ret = calculate_integrity_table(fd, new_lookup_table_end,
+ old_table, old_lookup_table_end,
+ progress_func, &new_table);
+ if (ret)
+ goto out_free_old_table;
- size_t bytes_to_read = min(INTEGRITY_CHUNK_SIZE, bytes_remaining);
- size_t bytes_read = fread(chunk_buf, 1, bytes_to_read, out);
- if (bytes_read != bytes_to_read) {
- if (feof(out)) {
- ERROR("Unexpected EOF while calculating "
- "integrity checksums");
- } else {
- ERROR_WITH_ERRNO("File stream error while "
- "calculating integrity "
- "checksums");
- }
- ret = WIMLIB_ERR_READ;
- goto out_free_chunk_buf;
+ new_table_size = new_table->size;
+
+ new_table->size = cpu_to_le32(new_table->size);
+ new_table->num_entries = cpu_to_le32(new_table->num_entries);
+ new_table->chunk_size = cpu_to_le32(new_table->chunk_size);
+
+ if (full_write(fd, new_table, new_table_size) != new_table_size) {
+ ERROR_WITH_ERRNO("Failed to write WIM integrity table");
+ ret = WIMLIB_ERR_WRITE;
+ } else {
+ integrity_res_entry->offset = cur_offset;
+ integrity_res_entry->size = new_table_size;
+ integrity_res_entry->original_size = new_table_size;
+ integrity_res_entry->flags = 0;
+ ret = 0;
+ }
+ FREE(new_table);
+out_free_old_table:
+ FREE(old_table);
+ return ret;
+}
+
+/*
+ * verify_integrity():
+ *
+ * Checks a WIM for consistency with the integrity table.
+ *
+ * @in_fd:
+ * File descriptor to the WIM file, opened for reading.
+ *
+ * @table:
+ * The integrity table for the WIM, read into memory.
+ *
+ * @bytes_to_check:
+ * Number of bytes in the WIM that need to be checked (offset of end of the
+ * lookup table minus offset of end of the header).
+ *
+ * @progress_func
+ * If non-NULL, a progress function that will be called after every
+ * verified chunk.
+ *
+ * Returns:
+ * > 0 (WIMLIB_ERR_*) on error
+ * 0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
+ * were no inconsistencies.
+ * -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
+ */
+static int
+verify_integrity(int in_fd, const tchar *filename,
+ const struct integrity_table *table,
+ u64 bytes_to_check,
+ wimlib_progress_func_t progress_func)
+{
+ int ret;
+ u64 offset = WIM_HEADER_DISK_SIZE;
+ u8 sha1_md[SHA1_HASH_SIZE];
+ union wimlib_progress_info progress;
+
+ if (progress_func) {
+ progress.integrity.total_bytes = bytes_to_check;
+ progress.integrity.total_chunks = table->num_entries;
+ progress.integrity.completed_chunks = 0;
+ progress.integrity.completed_bytes = 0;
+ progress.integrity.chunk_size = table->chunk_size;
+ progress.integrity.filename = filename;
+ progress_func(WIMLIB_PROGRESS_MSG_VERIFY_INTEGRITY,
+ &progress);
+ }
+ for (u32 i = 0; i < table->num_entries; i++) {
+ size_t this_chunk_size;
+ if (i == table->num_entries - 1)
+ this_chunk_size = MODULO_NONZERO(bytes_to_check,
+ table->chunk_size);
+ else
+ this_chunk_size = table->chunk_size;
+
+ ret = calculate_chunk_sha1(in_fd, this_chunk_size, offset, sha1_md);
+ if (ret)
+ return ret;
+
+ if (!hashes_equal(sha1_md, table->sha1sums[i]))
+ return WIM_INTEGRITY_NOT_OK;
+
+ offset += this_chunk_size;
+ if (progress_func) {
+ progress.integrity.completed_chunks++;
+ progress.integrity.completed_bytes += this_chunk_size;
+ progress_func(WIMLIB_PROGRESS_MSG_VERIFY_INTEGRITY,
+ &progress);
}
- sha1_buffer(chunk_buf, bytes_read, p);
- p += SHA1_HASH_SIZE;
- bytes_remaining -= bytes_read;
}
- if (show_progress)
- puts("Calculating integrity checksums for WIM "
- "(0 bytes remaining, 100% done)"
- " ");
-
- if (fseeko(out, 0, SEEK_END) != 0) {
- ERROR_WITH_ERRNO("Failed to seek to end of WIM to write "
- "integrity table");
- ret = WIMLIB_ERR_WRITE;
- goto out_free_chunk_buf;
+ return WIM_INTEGRITY_OK;
+}
+
+
+/*
+ * 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
+ * table.
+ *
+ * @w:
+ * The WIM, opened for reading, and with the header already read.
+ *
+ * @progress_func
+ * If non-NULL, a progress function that will be called after every
+ * verified chunk.
+ *
+ * Returns:
+ * > 0 (WIMLIB_ERR_*) on error
+ * 0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
+ * were no inconsistencies.
+ * -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
+ * -2 (WIM_INTEGRITY_NONEXISTENT) if the WIM contains no integrity
+ * information.
+ */
+int
+check_wim_integrity(WIMStruct *w, wimlib_progress_func_t progress_func)
+{
+ int ret;
+ u64 bytes_to_check;
+ struct integrity_table *table;
+ u64 end_lookup_table_offset;
+
+ if (w->hdr.integrity.offset == 0) {
+ DEBUG("No integrity information.");
+ return WIM_INTEGRITY_NONEXISTENT;
}
- if (fwrite(buf, 1, integrity_table_size, out) != integrity_table_size) {
- ERROR_WITH_ERRNO("Failed to write integrity table to end of "
- "WIM");
- ret = WIMLIB_ERR_WRITE;
- goto out_free_chunk_buf;
+ end_lookup_table_offset = w->hdr.lookup_table_res_entry.offset +
+ w->hdr.lookup_table_res_entry.size;
+
+ if (end_lookup_table_offset < WIM_HEADER_DISK_SIZE) {
+ ERROR("WIM lookup table ends before WIM header ends!");
+ return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
}
- ret = 0;
-out_free_chunk_buf:
- FREE(chunk_buf);
-out_free_buf:
- FREE(buf);
+
+ bytes_to_check = end_lookup_table_offset - WIM_HEADER_DISK_SIZE;
+
+ ret = read_integrity_table(&w->hdr.integrity, w->in_fd,
+ bytes_to_check, &table);
+ if (ret)
+ return ret;
+ ret = verify_integrity(w->in_fd, w->filename, table,
+ bytes_to_check, progress_func);
+ FREE(table);
return ret;
}
git://wimlib.net / wimlib / blobdiff