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path: root/archival/libunarchive/unxz/xz_dec_stream.c
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Diffstat (limited to 'archival/libunarchive/unxz/xz_dec_stream.c')
-rw-r--r--archival/libunarchive/unxz/xz_dec_stream.c113
1 files changed, 81 insertions, 32 deletions
diff --git a/archival/libunarchive/unxz/xz_dec_stream.c b/archival/libunarchive/unxz/xz_dec_stream.c
index 121c3b53a..21db283fb 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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-19 11:36:41 +0000