// object that has been uploaded using the S3 multipart
// API.
// An S3 multipart ETag has a -<part-number> suffix.
func (e ETag) IsMultipart() bool {
	return len(e) > 16 && !e.IsEncrypted() && bytes.ContainsRune(e, '-')
}

// Parts returns the number of object parts that are
// referenced by this ETag. It returns 1 if the object
// has been uploaded using the S3 singlepart API.
//

// md5sum
type SealMD5CurrFn func([]byte) []byte

// PutObjReader is a type that wraps sio.EncryptReader and
// underlying hash.Reader in a struct
type PutObjReader struct {
	*hash.Reader              // actual data stream
	rawReader    *hash.Reader // original data stream
	sealMD5Fn    SealMD5CurrFn
}

// Size returns the absolute number of bytes the Reader

  }

  /**
   * Computes the hash code of the {@code file} using {@code hashFunction}.
   *
   * @param file the file to read
   * @param hashFunction the hash function to use to hash the data
   * @return the {@link HashCode} of all of the bytes in the file
   * @throws IOException if an I/O error occurs
   * @since 12.0
   * @deprecated Prefer {@code asByteSource(file).hash(hashFunction)}.
   */
  @Deprecated

          && Objects.equals(getUpperEndpoint(), r.getUpperEndpoint());
    }
    return false;
  }

  @Override
  public int hashCode() {
    return Objects.hash(
        comparator,
        getLowerEndpoint(),
        getLowerBoundType(),
        getUpperEndpoint(),
        getUpperBoundType());
  }

  @LazyInit private transient @Nullable GeneralRange<T> reverse;

		parts := make([]CompletePart, len(objInfo.Parts))
		for i, part := range objInfo.Parts {
			hr, err := hash.NewReader(ctx, io.LimitReader(gr, part.Size), part.Size, "", "", part.ActualSize)
			if err != nil {
				return fmt.Errorf("decommissionObject: hash.NewReader() %w", err)
			}
			pi, err := z.PutObjectPart(ctx, bucket, objInfo.Name, res.UploadID,
				part.Number,
				NewPutObjReader(hr),

And be compatible with all of them at the same time.

///

Create a utility function to hash a password coming from the user.

And another utility to verify if a received password matches the hash stored.

And another one to authenticate and return a user.

}
```

Input for the key is the object name specified in `PutObject()`, returns a unique index. This index is one of the erasure sets where the object will reside. This function is a consistent hash for a given object name i.e for a given object name the index returned is always the same.

    --hash=sha256:0af291f4fe114be0280cdd29d533696a77b5b49cfde5467176ecab32353395c4 \
    --hash=sha256:0f55e69f030f7163dffe9fd0752b32f070566451afe180f99dbeeb81f511ad8d \
    --hash=sha256:1a2bc9f351a75ef49d664206d51f8e5ede9da246602dc2d2726837620ea034b2 \
    --hash=sha256:22e14b5d70560b8dd51ec22863f370d1e595ac3d024cb8ad7d308b4cd95f8313 \
    --hash=sha256:234ac59ea147c59ee4da87a0c0f098e9c8d169f4dc2a159ef720f1a61bbe27cd \

    --hash=sha256:0af291f4fe114be0280cdd29d533696a77b5b49cfde5467176ecab32353395c4 \
    --hash=sha256:0f55e69f030f7163dffe9fd0752b32f070566451afe180f99dbeeb81f511ad8d \
    --hash=sha256:1a2bc9f351a75ef49d664206d51f8e5ede9da246602dc2d2726837620ea034b2 \
    --hash=sha256:22e14b5d70560b8dd51ec22863f370d1e595ac3d024cb8ad7d308b4cd95f8313 \
    --hash=sha256:234ac59ea147c59ee4da87a0c0f098e9c8d169f4dc2a159ef720f1a61bbe27cd \

    --hash=sha256:0af291f4fe114be0280cdd29d533696a77b5b49cfde5467176ecab32353395c4 \
    --hash=sha256:0f55e69f030f7163dffe9fd0752b32f070566451afe180f99dbeeb81f511ad8d \
    --hash=sha256:1a2bc9f351a75ef49d664206d51f8e5ede9da246602dc2d2726837620ea034b2 \
    --hash=sha256:22e14b5d70560b8dd51ec22863f370d1e595ac3d024cb8ad7d308b4cd95f8313 \
    --hash=sha256:234ac59ea147c59ee4da87a0c0f098e9c8d169f4dc2a159ef720f1a61bbe27cd \