liblzma: Add support for LZMA_IGNORE_CHECK.
diff --git a/src/liblzma/api/lzma/container.h b/src/liblzma/api/lzma/container.h
index 891c6b7..b9c5e71 100644
--- a/src/liblzma/api/lzma/container.h
+++ b/src/liblzma/api/lzma/container.h
@@ -474,6 +474,30 @@
/**
+ * This flag makes lzma_code() not calculate and verify the integrity check
+ * of the compressed data in .xz files. This means that invalid integrity
+ * check values won't be detected and LZMA_DATA_ERROR won't be returned in
+ * such cases.
+ *
+ * This flag only affects the checks of the compressed data itself; the CRC32
+ * values in the .xz headers will still be verified normally.
+ *
+ * Don't use this flag unless you know what you are doing. Possible reasons
+ * to use this flag:
+ *
+ * - Trying to recover data from a corrupt .xz file.
+ *
+ * - Speeding up decompression, which matters mostly with SHA-256
+ * or with files that have compressed extremely well. It's recommended
+ * to not use this flag for this purpose unless the file integrity is
+ * verified externally in some other way.
+ *
+ * Support for this flag was added in liblzma 5.1.4beta.
+ */
+#define LZMA_IGNORE_CHECK UINT32_C(0x10)
+
+
+/**
* This flag enables decoding of concatenated files with file formats that
* allow concatenating compressed files as is. From the formats currently
* supported by liblzma, only the .xz format allows concatenated files.
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index b10a72e..af14e47 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -75,6 +75,7 @@
( LZMA_TELL_NO_CHECK \
| LZMA_TELL_UNSUPPORTED_CHECK \
| LZMA_TELL_ANY_CHECK \
+ | LZMA_IGNORE_CHECK \
| LZMA_CONCATENATED )
diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c
index 5243e4c..3ab938c 100644
--- a/src/liblzma/common/stream_decoder.c
+++ b/src/liblzma/common/stream_decoder.c
@@ -57,6 +57,10 @@
/// If true, LZMA_GET_CHECK is returned after decoding Stream Header.
bool tell_any_check;
+ /// If true, we will tell the Block decoder to skip calculating
+ /// and verifying the integrity check.
+ bool ignore_check;
+
/// If true, we will decode concatenated Streams that possibly have
/// Stream Padding between or after them. LZMA_STREAM_END is returned
/// once the application isn't giving us any new input, and we aren't
@@ -182,8 +186,8 @@
coder->pos = 0;
- // Version 0 is currently the only possible version.
- coder->block_options.version = 0;
+ // Version 1 is needed to support the .ignore_check option.
+ coder->block_options.version = 1;
// Set up a buffer to hold the filter chain. Block Header
// decoder will initialize all members of this array so
@@ -195,6 +199,11 @@
return_if_error(lzma_block_header_decode(&coder->block_options,
allocator, coder->buffer));
+ // If LZMA_IGNORE_CHECK was used, this flag needs to be set.
+ // It has to be set after lzma_block_header_decode() because
+ // it always resets this to false.
+ coder->block_options.ignore_check = coder->ignore_check;
+
// Check the memory usage limit.
const uint64_t memusage = lzma_raw_decoder_memusage(filters);
lzma_ret ret;
@@ -433,6 +442,7 @@
next->coder->tell_unsupported_check
= (flags & LZMA_TELL_UNSUPPORTED_CHECK) != 0;
next->coder->tell_any_check = (flags & LZMA_TELL_ANY_CHECK) != 0;
+ next->coder->ignore_check = (flags & LZMA_IGNORE_CHECK) != 0;
next->coder->concatenated = (flags & LZMA_CONCATENATED) != 0;
next->coder->first_stream = true;
