Implement inspect data API v2 (#15474)

Co-authored-by: Klaus Post <klauspost@gmail.com>

docs/debugging/inspect/decrypt-v2.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2015-2022 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/minio/madmin-go/estream"
+)
+
+func extractInspectV2(pk []byte, r io.Reader, w io.Writer) error {
+	privKey, err := bytesToPrivateKey(pk)
+	if err != nil {
+		return fmt.Errorf("decoding key returned: %w", err)
+	}
+
+	sr, err := estream.NewReader(r)
+	if err != nil {
+		return err
+	}
+
+	sr.SetPrivateKey(privKey)
+	sr.ReturnNonDecryptable(true)
+
+	// Debug corrupted streams.
+	if false {
+		sr.SkipEncrypted(true)
+		return sr.DebugStream(os.Stdout)
+	}
+
+	for {
+		stream, err := sr.NextStream()
+		if err != nil {
+			if err == io.EOF {
+				return errors.New("no data found on stream")
+			}
+			if errors.Is(err, estream.ErrNoKey) {
+				if stream.Name == "inspect.zip" {
+					return errors.New("incorrect private key")
+				}
+				if err := stream.Skip(); err != nil {
+					return fmt.Errorf("stream skip: %w", err)
+				}
+				continue
+			}
+			return fmt.Errorf("next stream: %w", err)
+		}
+		if stream.Name == "inspect.zip" {
+			_, err := io.Copy(w, stream)
+			if err != nil {
+				return fmt.Errorf("reading inspect stream: %w", err)
+			}
+			return nil
+		}
+		if err := stream.Skip(); err != nil {
+			return fmt.Errorf("stream skip: %w", err)
+		}
+	}
+}