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authorYann Collet <cyan@fb.com>2019-04-15 17:33:40 (GMT)
committerYann Collet <cyan@fb.com>2019-04-15 17:33:40 (GMT)
commit1f4a412646c82a7e0964b6c5b169d49ee072f475 (patch)
treefb7a0842a6d47188dcc1b068244b01c2c1fe6922 /lib/lz4.h
parent481a37fe472e88e276a90967984ce92abf0cff5e (diff)
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decompress*_fast() function do not generate deprecation warnings
they are classified as deprecated in the API documentation (lz4.h) but do not yet trigger a warning, to give time to existing applications to move away. Also, the _fast() variants are still ~5% faster than the _safe() ones after Dave's patch.
Diffstat (limited to 'lib/lz4.h')
-rw-r--r--lib/lz4.h27
1 files changed, 14 insertions, 13 deletions
diff --git a/lib/lz4.h b/lib/lz4.h
index 23b5ac5..1589be9 100644
--- a/lib/lz4.h
+++ b/lib/lz4.h
@@ -631,11 +631,11 @@ LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4
LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
/*! LZ4_decompress_fast() : **unsafe!**
- * These functions used to be a bit faster than LZ4_decompress_safe(),
- * but situation has changed in recent versions.
- * Now, `LZ4_decompress_safe()` is as fast and sometimes even faster than `LZ4_decompress_fast()`.
- * Moreover, LZ4_decompress_safe() is protected vs malformed input, while `LZ4_decompress_fast()` is not, making it a security liability.
+ * These functions are generally slightly faster than LZ4_decompress_safe(),
+ * though the difference is small (generally ~5%).
+ * However, the real cost is a risk : LZ4_decompress_safe() is protected vs malformed input, while `LZ4_decompress_fast()` is not, making it a security liability.
* As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated.
+ * These functions will generate a deprecation warning in the future.
*
* Last LZ4_decompress_fast() specificity is that it can decompress a block without knowing its compressed size.
* Note that even that functionality could be achieved in a more secure manner if need be,
@@ -648,18 +648,19 @@ LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4
* The function expects to finish at block's end exactly.
* If the source stream is detected malformed, the function stops decoding and returns a negative result.
* note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer.
- * However, since it doesn't know its 'src' size, it may read an unknown amount of input, and overflow input buffer.
- * Also, since match offsets are not validated, match reads from 'src' may underflow.
- * These issues never happen if input data is correct.
+ * However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds.
+ * Also, since match offsets are not validated, match reads from 'src' may underflow too.
+ * These issues never happen if input (compressed) data is correct.
* But they may happen if input data is invalid (error or intentional tampering).
* As a consequence, use these functions in trusted environments with trusted data **only**.
*/
-LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead") LZ4LIB_API
-int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
-LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead") LZ4LIB_API
-int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
-LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead") LZ4LIB_API
-int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
+
+/* LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead") */
+LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
+/* LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead") */
+LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
+/* LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead") */
+LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
/*! LZ4_resetStream() :
* An LZ4_stream_t structure must be initialized at least once.