The `ioutil.NopCloser(reader)` was hiding nested hash readers.
We make it an `io.Closer` so it can be attached without wrapping
and allows for nesting, by merging the requests.
This commit fixes a DoS vulnerability for certain APIs using
signature V4 by verifying the content-md5 and/or content-sha56 of
the request body in a streaming mode.
The issue was caused by reading the entire body of the request into
memory to verify the content-md5 or content-sha56 checksum if present.
The vulnerability could be exploited by either replaying a V4 request
(in the 15 min time frame) or sending a V4 presigned request with a
large body.
This change replaces all imports of "crypto/sha256" with
"github.com/minio/sha256-simd". The sha256-simd package
is faster on ARM64 (NEON instructions) and can take advantage
of AVX-512 in certain scenarios.
Fixes#5374
- Use it to send the Content-MD5 header correctly encoded to S3
Gateway
- Fixes a bug in PutObject (including anonymous PutObject) and
PutObjectPart with S3 Gateway found when testing with Mint.
Verify() was being called by caller after the data
has been successfully read after io.EOF. This disconnection
opens a race under concurrent access to such an object.
Verification is not necessary outside of Read() call,
we can simply just do checksum verification right inside
Read() call at io.EOF.
This approach simplifies the usage.
