Some code reorganization needed for an internal change.
R=fikes
git-svn-id: https://snappy.googlecode.com/svn/trunk@75 03e5f5b5-db94-4691-08a0-1a8bf15f6143
diff --git a/snappy.cc b/snappy.cc
index 1230321..3ea6db8 100644
--- a/snappy.cc
+++ b/snappy.cc
@@ -839,27 +839,18 @@
}
template <typename Writer>
-static bool InternalUncompress(Source* r,
- Writer* writer,
- uint32 max_len) {
+static bool InternalUncompress(Source* r, Writer* writer) {
// Read the uncompressed length from the front of the compressed input
SnappyDecompressor decompressor(r);
uint32 uncompressed_len = 0;
if (!decompressor.ReadUncompressedLength(&uncompressed_len)) return false;
- return InternalUncompressAllTags(
- &decompressor, writer, uncompressed_len, max_len);
+ return InternalUncompressAllTags(&decompressor, writer, uncompressed_len);
}
template <typename Writer>
static bool InternalUncompressAllTags(SnappyDecompressor* decompressor,
Writer* writer,
- uint32 uncompressed_len,
- uint32 max_len) {
- // Protect against possible DoS attack
- if (static_cast<uint64>(uncompressed_len) > max_len) {
- return false;
- }
-
+ uint32 uncompressed_len) {
writer->SetExpectedLength(uncompressed_len);
// Process the entire input
@@ -1039,7 +1030,7 @@
bool RawUncompress(Source* compressed, char* uncompressed) {
SnappyArrayWriter output(uncompressed);
- return InternalUncompress(compressed, &output, kuint32max);
+ return InternalUncompress(compressed, &output);
}
bool Uncompress(const char* compressed, size_t n, string* uncompressed) {
@@ -1047,9 +1038,9 @@
if (!GetUncompressedLength(compressed, n, &ulength)) {
return false;
}
- // Protect against possible DoS attack
- if ((static_cast<uint64>(ulength) + uncompressed->size()) >
- uncompressed->max_size()) {
+ // On 32-bit builds: max_size() < kuint32max. Check for that instead
+ // of crashing (e.g., consider externally specified compressed data).
+ if (ulength > uncompressed->max_size()) {
return false;
}
STLStringResizeUninitialized(uncompressed, ulength);
@@ -1088,7 +1079,7 @@
bool IsValidCompressedBuffer(const char* compressed, size_t n) {
ByteArraySource reader(compressed, n);
SnappyDecompressionValidator writer;
- return InternalUncompress(&reader, &writer, kuint32max);
+ return InternalUncompress(&reader, &writer);
}
void RawCompress(const char* input,
