From 90b0a05579001a4474b69f65c98501bb8078a8c3 Mon Sep 17 00:00:00 2001 From: Szymon Janc Date: Sun, 21 Aug 2011 18:48:19 +0200 Subject: [PATCH] Various bug fixes and improvements in lzopio. Should properly handle more files now. Also added support for lzop checksums verification. --- grub-core/io/lzopio.c | 158 ++++++++++++++++++++++++++++-------------- 1 file changed, 105 insertions(+), 53 deletions(-) diff --git a/grub-core/io/lzopio.c b/grub-core/io/lzopio.c index 4ccc41a16..f80d4beb9 100644 --- a/grub-core/io/lzopio.c +++ b/grub-core/io/lzopio.c @@ -22,17 +22,15 @@ #include #include #include - +#include #include "minilzo.h" GRUB_MOD_LICENSE ("GPLv3+"); #define LZOP_MAGIC "\x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a" #define LZOP_MAGIC_SIZE 9 -#define CHECK_SIZE 4 -#define NEW_LZO_LIB 0x0940 -#define MIN_HEADER_SIZE 0 -#define MAX_HEADER_SIZE 0 +#define LZOP_CHECK_SIZE 4 +#define LZOP_NEW_LIB 0x0940 /* Header flags - copied from conf.h of LZOP source code. */ #define F_ADLER32_D 0x00000001L @@ -64,8 +62,10 @@ struct block_header struct grub_lzopio { grub_file_t file; - int ucheck; /* XXX Use gcry to validate checks. */ - int ccheck; + int has_ccheck; + int has_ucheck; + const gcry_md_spec_t *ucheck_fun; + const gcry_md_spec_t *ccheck_fun; grub_off_t saved_off; /* Rounded down to block boundary. */ grub_off_t start_block_off; struct block_header block; @@ -74,15 +74,16 @@ struct grub_lzopio typedef struct grub_lzopio *grub_lzopio_t; static struct grub_fs grub_lzopio_fs; -/* Some helper functions. Memory allocated by those function is free either - * on next read_block_header() or on close() so no risk of leaks. This makes - * those function simpler. */ +/* Some helper functions. On errors memory allocated by those function is free + * either on close() so no risk of leaks. This makes functions simpler. */ /* Read block header from file, after successful exit file points to * beginning of block data. */ static int read_block_header (struct grub_lzopio *lzopio) { + lzopio->saved_off += lzopio->block.usize; + /* Free cached block data if any. */ grub_free (lzopio->block.udata); grub_free (lzopio->block.cdata); @@ -113,26 +114,40 @@ read_block_header (struct grub_lzopio *lzopio) lzopio->block.csize = grub_be_to_cpu32 (lzopio->block.csize); - /* XXX Handle incompressible data case here rather than in uncompress_block. - * This will allow to handle switch of ccheck/ucheck easier and also - * make uncompress_block() a bit simpler. */ + /* Corrupted. */ + if (lzopio->block.csize > lzopio->block.usize) + return -1; - /* Read data checks. */ - if (lzopio->ucheck) + /* Read checksum of uncompressed data. */ + if (lzopio->has_ucheck) { if (grub_file_read (lzopio->file, &lzopio->block.ucheck, sizeof (lzopio->block.ucheck)) != sizeof (lzopio->block.ucheck)) return -1; + + lzopio->block.ucheck = grub_be_to_cpu32 (lzopio->block.ucheck); } - if (lzopio->ccheck) + /* Read checksum of compressed data. */ + if (lzopio->has_ccheck) { - if (grub_file_read (lzopio->file, &lzopio->block.ccheck, - sizeof (lzopio->block.ccheck)) != - sizeof (lzopio->block.ccheck)) - return -1; + /* Incompressible data block. */ + if (lzopio->block.csize == lzopio->block.usize) + { + lzopio->block.ccheck = lzopio->block.ucheck; + } + else + { + if (grub_file_read (lzopio->file, &lzopio->block.ccheck, + sizeof (lzopio->block.ccheck)) != + sizeof (lzopio->block.ccheck)) + return -1; + + lzopio->block.ccheck = grub_be_to_cpu32 (lzopio->block.ccheck); + } } + return 0; } @@ -149,9 +164,19 @@ read_block_data (struct grub_lzopio *lzopio) != (grub_ssize_t) lzopio->block.csize) return -1; - if (lzopio->ccheck) + if (lzopio->ccheck_fun) { - /* XXX Validate data checksum here. */ + grub_uint8_t context[lzopio->ccheck_fun->contextsize]; + + lzopio->ccheck_fun->init (context); + lzopio->ccheck_fun->write (context, lzopio->block.cdata, + lzopio->block.csize); + lzopio->ccheck_fun->final (context); + + if (grub_memcmp + (lzopio->ccheck_fun->read (context), &lzopio->block.ccheck, + sizeof (lzopio->block.ccheck)) != 0) + return -1; } return 0; @@ -159,7 +184,7 @@ read_block_data (struct grub_lzopio *lzopio) /* Read block data, uncompressed and also store it in memory. */ /* XXX Investigate possibility of in-place decompression to reduce memory - * footprint. */ + * footprint. Or try to uncompress directly to buf if possible. */ static int uncompress_block (struct grub_lzopio *lzopio) { @@ -168,36 +193,42 @@ uncompress_block (struct grub_lzopio *lzopio) if (read_block_data (lzopio) < 0) return -1; - if (lzopio->block.usize > lzopio->block.csize) + /* Incompressible data. */ + if (lzopio->block.csize == lzopio->block.usize) + { + lzopio->block.udata = lzopio->block.cdata; + lzopio->block.cdata = NULL; + } + else { lzopio->block.udata = grub_malloc (lzopio->block.usize); if (!lzopio->block.udata) return -1; if (lzo1x_decompress_safe (lzopio->block.cdata, lzopio->block.csize, - lzopio->block.udata, &usize, - NULL) != LZO_E_OK) + lzopio->block.udata, &usize, NULL) + != LZO_E_OK) return -1; - if (lzopio->ucheck) + if (lzopio->ucheck_fun) { - /* XXX Validate data checksum here. */ + grub_uint8_t context[lzopio->ucheck_fun->contextsize]; + + lzopio->ucheck_fun->init (context); + lzopio->ucheck_fun->write (context, lzopio->block.udata, + lzopio->block.usize); + lzopio->ucheck_fun->final (context); + + if (grub_memcmp + (lzopio->ucheck_fun->read (context), &lzopio->block.ucheck, + sizeof (lzopio->block.ucheck)) != 0) + return -1; } /* Compressed data can be free now. */ grub_free (lzopio->block.cdata); lzopio->block.cdata = NULL; } - /* Incompressible block of data. */ - else if (lzopio->block.usize == lzopio->block.csize) - { - lzopio->block.udata = lzopio->block.cdata; - lzopio->block.cdata = NULL; - } - else - { - return -1; - } return 0; } @@ -215,8 +246,6 @@ jump_block (struct grub_lzopio *lzopio) return -1; } - lzopio->saved_off += lzopio->block.usize; - return read_block_header (lzopio); } @@ -243,7 +272,7 @@ calculate_uncompressed_size (grub_file_t file) return 1; } -/* XXX Do something with this function, it is insane now:) */ +/* XXX Do something with this function... */ static int test_header (grub_file_t file) { @@ -253,6 +282,7 @@ test_header (grub_file_t file) grub_uint8_t method, level, name_len; grub_uint32_t flags, mode, filter, mtime_lo, mtime_hi, checksum; unsigned char *name = NULL; + const gcry_md_spec_t *hcheck; if (grub_file_read (lzopio->file, magic, sizeof (magic)) != sizeof (magic)) { @@ -277,7 +307,7 @@ test_header (grub_file_t file) ver = grub_be_to_cpu16 (ver); - if (ver >= NEW_LZO_LIB) + if (ver >= LZOP_NEW_LIB) { /* Read version of lib needed to extract data. */ if (grub_file_read (lzopio->file, &ver_ext, sizeof (ver_ext)) != @@ -297,7 +327,7 @@ test_header (grub_file_t file) sizeof (method)) goto CORRUPTED; - if (ver >= NEW_LZO_LIB) + if (ver >= LZOP_NEW_LIB) { if (grub_file_read (lzopio->file, &level, sizeof (level)) != sizeof (level)) @@ -310,14 +340,33 @@ test_header (grub_file_t file) flags = grub_be_to_cpu32 (flags); if (flags & F_CRC32_D) - lzopio->ucheck = 1; + { + lzopio->has_ucheck = 1; + lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("crc32"); + } else if (flags & F_ADLER32_D) - lzopio->ucheck = 2; + { + lzopio->has_ucheck = 1; + lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("adler32"); + } if (flags & F_CRC32_C) - lzopio->ccheck = 1; + { + lzopio->has_ccheck = 1; + lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("crc32"); + } else if (flags & F_ADLER32_C) - lzopio->ccheck = 2; + { + lzopio->has_ccheck = 1; + lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("adler32"); + } + + if (flags & F_H_CRC32) + hcheck = grub_crypto_lookup_md_by_name ("crc32"); + else + hcheck = grub_crypto_lookup_md_by_name ("adler32"); + + hcheck++; if (flags & F_H_FILTER) { @@ -333,7 +382,7 @@ test_header (grub_file_t file) sizeof (mtime_lo)) goto CORRUPTED; - if (ver >= NEW_LZO_LIB) + if (ver >= LZOP_NEW_LIB) { if (grub_file_read (lzopio->file, &mtime_hi, sizeof (mtime_hi)) != sizeof (mtime_hi)) @@ -374,8 +423,6 @@ test_header (grub_file_t file) if (calculate_uncompressed_size (file) < 0) goto CORRUPTED; - lzopio->saved_off = 0; - /* Get back to start block. */ grub_file_seek (lzopio->file, lzopio->start_block_off); @@ -383,6 +430,7 @@ test_header (grub_file_t file) if (read_block_header (lzopio) < 0) goto CORRUPTED; + lzopio->saved_off = 0; return 1; } @@ -439,15 +487,17 @@ grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len) { grub_lzopio_t lzopio = file->data; grub_ssize_t ret = 0; + grub_off_t off; /* Backward seek before last read block. */ if (lzopio->saved_off > grub_file_tell (file)) { - lzopio->saved_off = 0; grub_file_seek (lzopio->file, lzopio->start_block_off); if (read_block_header (lzopio) < 0) goto CORRUPTED; + + lzopio->saved_off = 0; } /* Forward to first block with requested data. */ @@ -461,9 +511,10 @@ grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len) goto CORRUPTED; } + off = grub_file_tell (file) - lzopio->saved_off; + while (len != 0 && lzopio->block.usize != 0) { - grub_off_t off = grub_file_tell (file) - lzopio->saved_off; long to_copy; /* Block not decompressed yet. */ @@ -477,8 +528,9 @@ grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len) len -= to_copy; buf += to_copy; ret += to_copy; + off = 0; - /* Read to next block if needed. */ + /* Read next block if needed. */ if (len > 0 && read_block_header (lzopio) < 0) goto CORRUPTED; } -- 2.47.3