1 files changed, 35 insertions, 12 deletions

diff --git a/src/liblzma/check/check.h b/src/liblzma/check/check.h
index 74279ceb..45ca25e9 100644
--- a/src/liblzma/check/check.h
+++ b/src/liblzma/check/check.h
@@ -17,15 +17,21 @@
 #include "common.h"
 
 
+// Index hashing used to verify the Index with O(1) memory usage needs
+// a good hash function.
+#if defined(HAVE_CHECK_SHA256)
+#	define LZMA_CHECK_BEST LZMA_CHECK_SHA256
+#elif defined(HAVE_CHECK_CRC64)
+#	define LZMA_CHECK_BEST LZMA_CHECK_CRC64
+#else
+#	define LZMA_CHECK_BEST LZMA_CHECK_CRC32
+#endif
+
+
 typedef struct {
 	/// Internal state
 	uint32_t state[8];
 
-	/// Temporary 8-byte aligned buffer to hold incomplete chunk.
-	/// After lzma_check_finish(), the first 32 bytes will contain
-	/// the final digest in big endian byte order.
-	uint8_t buffer[64];
-
 	/// Size of the message excluding padding
 	uint64_t size;
 
@@ -34,10 +40,27 @@ typedef struct {
 
 /// \note       This is not in the public API because this structure will
 ///             change in future.
-typedef union {
-	uint32_t crc32;
-	uint64_t crc64;
-	lzma_sha256 sha256;
+typedef struct {
+	// FIXME Guarantee 8-byte alignment
+
+	/// Buffer to hold the final result; this is also used as a temporary
+	/// buffer in SHA256. Note that this buffer must be 8-byte aligned.
+	uint8_t buffer[64];
+
+	/// Check-specific data
+	union {
+		uint32_t crc32;
+		uint64_t crc64;
+
+		struct {
+			/// Internal state
+			uint32_t state[8];
+
+			/// Size of the message excluding padding
+			uint64_t size;
+		} sha256;
+	} state;
+
 } lzma_check;
 
 
@@ -91,12 +114,12 @@ extern void lzma_crc64_init(void);
 
 // SHA256
 
-extern void lzma_sha256_init(lzma_sha256 *sha256);
+extern void lzma_sha256_init(lzma_check *check);
 
 extern void lzma_sha256_update(
-		const uint8_t *buf, size_t size, lzma_sha256 *sha256);
+		const uint8_t *buf, size_t size, lzma_check *check);
 
-extern void lzma_sha256_finish(lzma_sha256 *sha256);
+extern void lzma_sha256_finish(lzma_check *check);
 
 
 #endif