diff options
Diffstat (limited to 'doc/lz4_manual.html')
| -rw-r--r-- | doc/lz4_manual.html | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html index f8639fe..ddd2724 100644 --- a/doc/lz4_manual.html +++ b/doc/lz4_manual.html @@ -126,15 +126,17 @@ int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int src <pre><b>int LZ4_decompress_fast (const char* src, char* dst, int originalSize); </b><p>This function is a bit faster than LZ4_decompress_safe(), -but doesn't provide any security guarantee. +but it may misbehave on malformed input because it doesn't perform full validation of compressed data. originalSize : is the uncompressed size to regenerate Destination buffer must be already allocated, and its size must be >= 'originalSize' bytes. return : number of bytes read from source buffer (== compressed size). If the source stream is detected malformed, the function stops decoding and return a negative result. - note : This function respects memory boundaries for *properly formed* compressed data. - However, it does not provide any protection against malicious input. - It also doesn't know 'src' size, and implies it's >= compressed size. - Use this function in trusted environment **only**. + note : This function is only usable if the originalSize of uncompressed data is known in advance. + The caller should also check that all the compressed input has been consumed properly, + i.e. that the return value matches the size of the buffer with compressed input. + The function never writes past the output buffer. However, since it doesn't know its 'src' size, + it may read past the intended input. Also, because match offsets are not validated during decoding, + reads from 'src' may underflow. Use this function in trusted environment **only**. </p></pre><BR> <pre><b>int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity); |