[git commit master] decompress_unxz: newer version, one which can unpack SHA-256 protected files
Denys Vlasenko
vda.linux at googlemail.com
Tue Jun 1 12:41:39 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=716f3f612e62c55edd052b505a86e4e2e09074a5
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
check_sizes - 16 +16
crc32_table - 4 +4
index_update 47 40 -7
crc32_validate 110 93 -17
dec_vli 197 165 -32
unpack_xz_stream 4284 4014 -270
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/4 up/down: 20/-326) Total: -306 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
archival/libunarchive/decompress_unxz.c | 18 +++--
archival/libunarchive/unxz/xz.h | 58 +++++++++------
archival/libunarchive/unxz/xz_config.h | 6 +-
archival/libunarchive/unxz/xz_dec_bcj.c | 10 ++-
archival/libunarchive/unxz/xz_dec_stream.c | 113 ++++++++++++++++++++--------
archival/libunarchive/unxz/xz_private.h | 2 +-
archival/libunarchive/unxz/xz_stream.h | 15 +++-
7 files changed, 154 insertions(+), 68 deletions(-)
diff --git a/archival/libunarchive/decompress_unxz.c b/archival/libunarchive/decompress_unxz.c
index 924a525..374b76d 100644
--- a/archival/libunarchive/decompress_unxz.c
+++ b/archival/libunarchive/decompress_unxz.c
@@ -16,9 +16,13 @@
#define XZ_FUNC FAST_FUNC
#define XZ_EXTERN static
-#define xz_crc32_init(table) crc32_filltable(table, /*endian:*/ 0)
-static uint32_t xz_crc32(uint32_t *crc32_table,
- const uint8_t *buf, size_t size, uint32_t crc)
+/* Skip check (rather than fail) of unsupported hash functions */
+#define XZ_DEC_ANY_CHECK 1
+
+/* We use our own crc32 function */
+#define XZ_INTERNAL_CRC32 0
+static uint32_t *crc32_table;
+static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
{
crc = ~crc;
@@ -29,8 +33,8 @@ static uint32_t xz_crc32(uint32_t *crc32_table,
return ~crc;
}
-#define xz_crc32 xz_crc32
+/* We use arch-optimized unaligned accessors */
#define get_unaligned_le32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_LE32(v); })
#define get_unaligned_be32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_BE32(v); })
#define put_unaligned_le32(val, buf) move_to_unaligned16(buf, SWAP_LE32(val))
@@ -64,8 +68,10 @@ unpack_xz_stream(int src_fd, int dst_fd)
iobuf.out = membuf + IN_SIZE;
iobuf.out_size = OUT_SIZE;
+ if (!crc32_table)
+ crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
+
state = xz_dec_init(64*1024); /* initial dict of 64k */
- xz_crc32_init(state->crc32_table);
while (1) {
enum xz_ret r;
@@ -102,7 +108,7 @@ unpack_xz_stream(int src_fd, int dst_fd)
) {
break;
}
- if (r != XZ_OK) {
+ if (r != XZ_OK && r != XZ_UNSUPPORTED_CHECK) {
bb_error_msg("corrupted data");
total = -1;
break;
diff --git a/archival/libunarchive/unxz/xz.h b/archival/libunarchive/unxz/xz.h
index dbb9ba9..eb82706 100644
--- a/archival/libunarchive/unxz/xz.h
+++ b/archival/libunarchive/unxz/xz.h
@@ -31,20 +31,29 @@
/**
* enum xz_ret - Return codes
- * @XZ_OK: Everything is OK so far. More input or more output
- * space is required to continue.
- * @XZ_STREAM_END: Operation finished successfully.
- * @XZ_MEMLIMIT_ERROR: Not enough memory was preallocated at decoder
- * initialization time.
- * @XZ_FORMAT_ERROR: File format was not recognized (wrong magic bytes).
- * @XZ_OPTIONS_ERROR: This implementation doesn't support the requested
- * compression options. In the decoder this means that
- * the header CRC32 matches, but the header itself
- * specifies something that we don't support.
- * @XZ_DATA_ERROR: Compressed data is corrupt.
- * @XZ_BUF_ERROR: Cannot make any progress. Details are slightly
- * different between multi-call and single-call mode;
- * more information below.
+ * @XZ_OK: Everything is OK so far. More input or more
+ * output space is required to continue.
+ * @XZ_STREAM_END: Operation finished successfully.
+ * @XZ_UNSUPPORTED_CHECK: Integrity check type is not supported. Decoding
+ * is still possible in multi-call mode by simply
+ * calling xz_dec_run() again.
+ * NOTE: This return value is used only if
+ * XZ_DEC_ANY_CHECK was defined at build time,
+ * which is not used in the kernel. Unsupported
+ * check types return XZ_OPTIONS_ERROR if
+ * XZ_DEC_ANY_CHECK was not defined at build time.
+ * @XZ_MEMLIMIT_ERROR: Not enough memory was preallocated at decoder
+ * initialization time.
+ * @XZ_FORMAT_ERROR: File format was not recognized (wrong magic
+ * bytes).
+ * @XZ_OPTIONS_ERROR: This implementation doesn't support the requested
+ * compression options. In the decoder this means
+ * that the header CRC32 matches, but the header
+ * itself specifies something that we don't support.
+ * @XZ_DATA_ERROR: Compressed data is corrupt.
+ * @XZ_BUF_ERROR: Cannot make any progress. Details are slightly
+ * different between multi-call and single-call
+ * mode; more information below.
*
* In multi-call mode, XZ_BUF_ERROR is returned when two consecutive calls
* to XZ code cannot consume any input and cannot produce any new output.
@@ -62,6 +71,7 @@
enum xz_ret {
XZ_OK,
XZ_STREAM_END,
+ XZ_UNSUPPORTED_CHECK,
XZ_MEMLIMIT_ERROR,
XZ_FORMAT_ERROR,
XZ_OPTIONS_ERROR,
@@ -129,7 +139,7 @@ struct xz_dec;
*
* Because the output buffer is used as the workspace, streams encoded using
* a big dictionary are not a problem in single-call. It is enough that the
- * output buffer is is big enough to hold the actual uncompressed data; it
+ * output buffer is big enough to hold the actual uncompressed data; it
* can be smaller than the dictionary size stored in the stream headers.
*
* On success, xz_dec_init() returns a pointer to struct xz_dec, which is
@@ -186,23 +196,27 @@ XZ_EXTERN void XZ_FUNC xz_dec_end(struct xz_dec *s);
* CRC32 module is used instead, and users of this module don't need to
* care about the functions below.
*/
-#if !defined(__KERNEL__) || defined(XZ_INTERNAL_CRC32)
+#ifndef XZ_INTERNAL_CRC32
+# ifdef __KERNEL__
+# define XZ_INTERNAL_CRC32 0
+# else
+# define XZ_INTERNAL_CRC32 1
+# endif
+#endif
+
+#if XZ_INTERNAL_CRC32
/*
* This must be called before any other xz_* function to initialize
* the CRC32 lookup table.
*/
-#ifndef xz_crc32_init
-XZ_EXTERN void XZ_FUNC xz_crc32_init(uint32_t *crc32_table);
-#endif
+XZ_EXTERN void XZ_FUNC xz_crc32_init(void);
/*
* Update CRC32 value using the polynomial from IEEE-802.3. To start a new
* calculation, the third argument must be zero. To continue the calculation,
* the previously returned value is passed as the third argument.
*/
-#ifndef xz_crc32
-XZ_EXTERN uint32_t XZ_FUNC xz_crc32(uint32_t *crc32_table,
+XZ_EXTERN uint32_t XZ_FUNC xz_crc32(
const uint8_t *buf, size_t size, uint32_t crc);
#endif
#endif
-#endif
diff --git a/archival/libunarchive/unxz/xz_config.h b/archival/libunarchive/unxz/xz_config.h
index 3259815..ff90eff 100644
--- a/archival/libunarchive/unxz/xz_config.h
+++ b/archival/libunarchive/unxz/xz_config.h
@@ -43,7 +43,7 @@
* becomes slow.
*
* NOTE: System headers on GNU/Linux may #define this macro already,
- * so if you want to change it, it you need to #undef it first.
+ * so if you want to change it, you need to #undef it first.
*/
#ifndef __always_inline
# ifdef __GNUC__
@@ -114,6 +114,8 @@ static inline void XZ_FUNC put_unaligned_be32(uint32_t val, uint8_t *buf)
* little endian systems, #define get_le32(ptr) (*(const uint32_t *)(ptr))
* could save a few bytes in code size.
*/
-#define get_le32 get_unaligned_le32
+#ifndef get_le32
+# define get_le32 get_unaligned_le32
+#endif
#endif
diff --git a/archival/libunarchive/unxz/xz_dec_bcj.c b/archival/libunarchive/unxz/xz_dec_bcj.c
index d4b6ef7..09162b5 100644
--- a/archival/libunarchive/unxz/xz_dec_bcj.c
+++ b/archival/libunarchive/unxz/xz_dec_bcj.c
@@ -10,6 +10,12 @@
#include "xz_private.h"
+/*
+ * The rest of the file is inside this ifdef. It makes things a little more
+ * convenient when building without support for any BCJ filters.
+ */
+#ifdef XZ_DEC_BCJ
+
struct xz_dec_bcj {
/* Type of the BCJ filter being used */
enum {
@@ -331,7 +337,6 @@ static noinline_for_stack size_t XZ_FUNC bcj_sparc(
}
#endif
-#ifdef XZ_DEC_BCJ
/*
* Apply the selected BCJ filter. Update *pos and s->pos to match the amount
* of data that got filtered.
@@ -388,9 +393,7 @@ static void XZ_FUNC bcj_apply(struct xz_dec_bcj *s,
*pos += filtered;
s->pos += filtered;
}
-#endif
-#ifdef XZ_DEC_BCJ
/*
* Flush pending filtered data from temp to the output buffer.
* Move the remaining mixture of possibly filtered and unfiltered
@@ -557,4 +560,5 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_bcj_reset(
return XZ_OK;
}
+
#endif
diff --git a/archival/libunarchive/unxz/xz_dec_stream.c b/archival/libunarchive/unxz/xz_dec_stream.c
index 121c3b5..21db283 100644
--- a/archival/libunarchive/unxz/xz_dec_stream.c
+++ b/archival/libunarchive/unxz/xz_dec_stream.c
@@ -45,8 +45,8 @@ struct xz_dec {
/* CRC32 value in Block or Index */
uint32_t crc32;
- /* True if CRC32 is calculated from uncompressed data */
- uint8_t crc_type;
+ /* Type of the integrity check calculated from uncompressed data */
+ enum xz_check check_type;
/* True if we are operating in single-call mode. */
bool single_call;
@@ -134,9 +134,19 @@ struct xz_dec {
struct xz_dec_bcj *bcj;
bool bcj_active;
#endif
+};
- uint32_t crc32_table[256];
+#ifdef XZ_DEC_ANY_CHECK
+/* Sizes of the Check field with different Check IDs */
+static const uint8_t check_sizes[16] = {
+ 0,
+ 4, 4, 4,
+ 8, 8, 8,
+ 16, 16, 16,
+ 32, 32, 32,
+ 64, 64, 64
};
+#endif
/*
* Fill s->temp by copying data starting from b->in[b->in_pos]. Caller
@@ -231,9 +241,8 @@ static enum xz_ret XZ_FUNC dec_block(struct xz_dec *s, struct xz_buf *b)
> s->block_header.uncompressed)
return XZ_DATA_ERROR;
- if (s->crc_type == 0x01)
- s->crc32 = xz_crc32(s->crc32_table,
- b->out + s->out_start,
+ if (s->check_type == XZ_CHECK_CRC32)
+ s->crc32 = xz_crc32(b->out + s->out_start,
b->out_pos - s->out_start, s->crc32);
if (ret == XZ_STREAM_END) {
@@ -249,15 +258,16 @@ static enum xz_ret XZ_FUNC dec_block(struct xz_dec *s, struct xz_buf *b)
s->block.hash.unpadded += s->block_header.size
+ s->block.compressed;
- if (s->crc_type == 0x01)
+
+#ifdef XZ_DEC_ANY_CHECK
+ s->block.hash.unpadded += check_sizes[s->check_type];
+#else
+ if (s->check_type == XZ_CHECK_CRC32)
s->block.hash.unpadded += 4;
- if (s->crc_type == 0x04) /* CRC64 */
- s->block.hash.unpadded += 8;
- if (s->crc_type == 0x0A) /* SHA-256 */
- s->block.hash.unpadded += 32;
+#endif
s->block.hash.uncompressed += s->block.uncompressed;
- s->block.hash.crc32 = xz_crc32(s->crc32_table,
+ s->block.hash.crc32 = xz_crc32(
(const uint8_t *)&s->block.hash,
sizeof(s->block.hash), s->block.hash.crc32);
@@ -272,7 +282,7 @@ static void XZ_FUNC index_update(struct xz_dec *s, const struct xz_buf *b)
{
size_t in_used = b->in_pos - s->in_start;
s->index.size += in_used;
- s->crc32 = xz_crc32(s->crc32_table, b->in + s->in_start, in_used, s->crc32);
+ s->crc32 = xz_crc32(b->in + s->in_start, in_used, s->crc32);
}
/*
@@ -316,7 +326,7 @@ static enum xz_ret XZ_FUNC dec_index(struct xz_dec *s, struct xz_buf *b)
case SEQ_INDEX_UNCOMPRESSED:
s->index.hash.uncompressed += s->vli;
- s->index.hash.crc32 = xz_crc32(s->crc32_table,
+ s->index.hash.crc32 = xz_crc32(
(const uint8_t *)&s->index.hash,
sizeof(s->index.hash),
s->index.hash.crc32);
@@ -352,31 +362,58 @@ static enum xz_ret XZ_FUNC crc32_validate(struct xz_dec *s, struct xz_buf *b)
return XZ_STREAM_END;
}
+#ifdef XZ_DEC_ANY_CHECK
+/*
+ * Skip over the Check field when the Check ID is not supported.
+ * Returns true once the whole Check field has been skipped over.
+ */
+static bool XZ_FUNC check_skip(struct xz_dec *s, struct xz_buf *b)
+{
+ while (s->pos < check_sizes[s->check_type]) {
+ if (b->in_pos == b->in_size)
+ return false;
+
+ ++b->in_pos;
+ ++s->pos;
+ }
+
+ s->pos = 0;
+
+ return true;
+}
+#endif
+
/* Decode the Stream Header field (the first 12 bytes of the .xz Stream). */
static enum xz_ret XZ_FUNC dec_stream_header(struct xz_dec *s)
{
if (!memeq(s->temp.buf, HEADER_MAGIC, HEADER_MAGIC_SIZE))
return XZ_FORMAT_ERROR;
- if (xz_crc32(s->crc32_table, s->temp.buf + HEADER_MAGIC_SIZE, 2, 0)
+ if (xz_crc32(s->temp.buf + HEADER_MAGIC_SIZE, 2, 0)
!= get_le32(s->temp.buf + HEADER_MAGIC_SIZE + 2))
return XZ_DATA_ERROR;
+ if (s->temp.buf[HEADER_MAGIC_SIZE] != 0)
+ return XZ_OPTIONS_ERROR;
+
/*
- * Decode the Stream Flags field. Of integrity checks, we support
- * only none (Check ID = 0) and CRC32 (Check ID = 1).
- * We also accept CRC64 and SHA-256, but they will not be verified.
+ * Of integrity checks, we support only none (Check ID = 0) and
+ * CRC32 (Check ID = 1). However, if XZ_DEC_ANY_CHECK is defined,
+ * we will accept other check types too, but then the check won't
+ * be verified and a warning (XZ_UNSUPPORTED_CHECK) will be given.
*/
- if (s->temp.buf[HEADER_MAGIC_SIZE] != 0
- || (s->temp.buf[HEADER_MAGIC_SIZE + 1] > 1
- && s->temp.buf[HEADER_MAGIC_SIZE + 1] != 0x04 /* CRC64 */
- && s->temp.buf[HEADER_MAGIC_SIZE + 1] != 0x0A /* SHA-256 */
- )
- ) {
+ s->check_type = s->temp.buf[HEADER_MAGIC_SIZE + 1];
+
+#ifdef XZ_DEC_ANY_CHECK
+ if (s->check_type > XZ_CHECK_MAX)
return XZ_OPTIONS_ERROR;
- }
- s->crc_type = s->temp.buf[HEADER_MAGIC_SIZE + 1];
+ if (s->check_type > XZ_CHECK_CRC32)
+ return XZ_UNSUPPORTED_CHECK;
+#else
+ if (s->check_type > XZ_CHECK_CRC32)
+ return XZ_OPTIONS_ERROR;
+#endif
return XZ_OK;
}
@@ -387,7 +424,7 @@ static enum xz_ret XZ_FUNC dec_stream_footer(struct xz_dec *s)
if (!memeq(s->temp.buf + 10, FOOTER_MAGIC, FOOTER_MAGIC_SIZE))
return XZ_DATA_ERROR;
- if (xz_crc32(s->crc32_table, s->temp.buf + 4, 6, 0) != get_le32(s->temp.buf))
+ if (xz_crc32(s->temp.buf + 4, 6, 0) != get_le32(s->temp.buf))
return XZ_DATA_ERROR;
/*
@@ -398,7 +435,7 @@ static enum xz_ret XZ_FUNC dec_stream_footer(struct xz_dec *s)
if ((s->index.size >> 2) != get_le32(s->temp.buf + 4))
return XZ_DATA_ERROR;
- if (s->temp.buf[8] != 0 || s->temp.buf[9] != s->crc_type)
+ if (s->temp.buf[8] != 0 || s->temp.buf[9] != s->check_type)
return XZ_DATA_ERROR;
/*
@@ -418,7 +455,7 @@ static enum xz_ret XZ_FUNC dec_block_header(struct xz_dec *s)
* eight bytes so this is safe.
*/
s->temp.size -= 4;
- if (xz_crc32(s->crc32_table, s->temp.buf, s->temp.size, 0)
+ if (xz_crc32(s->temp.buf, s->temp.size, 0)
!= get_le32(s->temp.buf + s->temp.size))
return XZ_DATA_ERROR;
@@ -533,12 +570,19 @@ static enum xz_ret XZ_FUNC dec_main(struct xz_dec *s, struct xz_buf *b)
if (!fill_temp(s, b))
return XZ_OK;
+ /*
+ * If dec_stream_header() returns
+ * XZ_UNSUPPORTED_CHECK, it is still possible
+ * to continue decoding if working in multi-call
+ * mode. Thus, update s->sequence before calling
+ * dec_stream_header().
+ */
+ s->sequence = SEQ_BLOCK_START;
+
ret = dec_stream_header(s);
if (ret != XZ_OK)
return ret;
- s->sequence = SEQ_BLOCK_START;
-
case SEQ_BLOCK_START:
/* We need one byte of input to continue. */
if (b->in_pos == b->in_size)
@@ -600,11 +644,16 @@ static enum xz_ret XZ_FUNC dec_main(struct xz_dec *s, struct xz_buf *b)
s->sequence = SEQ_BLOCK_CHECK;
case SEQ_BLOCK_CHECK:
- if (s->crc_type == 0x01) {
+ if (s->check_type == XZ_CHECK_CRC32) {
ret = crc32_validate(s, b);
if (ret != XZ_STREAM_END)
return ret;
}
+#ifdef XZ_DEC_ANY_CHECK
+ else if (!check_skip(s, b)) {
+ return XZ_OK;
+ }
+#endif
s->sequence = SEQ_BLOCK_START;
break;
diff --git a/archival/libunarchive/unxz/xz_private.h b/archival/libunarchive/unxz/xz_private.h
index 9da8d70..f4e0b40 100644
--- a/archival/libunarchive/unxz/xz_private.h
+++ b/archival/libunarchive/unxz/xz_private.h
@@ -112,9 +112,9 @@ XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_bcj_reset(
*/
XZ_EXTERN enum xz_ret XZ_FUNC xz_dec_bcj_run(struct xz_dec_bcj *s,
struct xz_dec_lzma2 *lzma2, struct xz_buf *b);
-#endif
/* Free the memory allocated for the BCJ filters. */
#define xz_dec_bcj_end(s) kfree(s)
+#endif
#endif
diff --git a/archival/libunarchive/unxz/xz_stream.h b/archival/libunarchive/unxz/xz_stream.h
index efbe75a..36f2a7c 100644
--- a/archival/libunarchive/unxz/xz_stream.h
+++ b/archival/libunarchive/unxz/xz_stream.h
@@ -10,10 +10,10 @@
#ifndef XZ_STREAM_H
#define XZ_STREAM_H
-#if defined(__KERNEL__) && !defined(XZ_INTERNAL_CRC32)
+#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
# include <linux/crc32.h>
# undef crc32
-# define xz_crc32(crc32_table, buf, size, crc) \
+# define xz_crc32(buf, size, crc) \
(~crc32_le(~(uint32_t)(crc), buf, size))
#endif
@@ -43,4 +43,15 @@ typedef uint64_t vli_type;
/* Maximum encoded size of a VLI */
#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
+/* Integrity Check types */
+enum xz_check {
+ XZ_CHECK_NONE = 0,
+ XZ_CHECK_CRC32 = 1,
+ XZ_CHECK_CRC64 = 4,
+ XZ_CHECK_SHA256 = 10
+};
+
+/* Maximum possible Check ID */
+#define XZ_CHECK_MAX 15
+
#endif
--
1.6.3.3
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