security: Remove insecure custom headers (#10244)

Background: https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w

Remove these custom headers from incoming and outgoing requests.

cmd/api-headers.go

@@ -128,6 +128,11 @@ func setObjectHeaders(w http.ResponseWriter, objInfo ObjectInfo, rs *HTTPRangeSp
 			// values to client.
 			continue
 		}
+
+		// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+		if strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentLength) || strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentMD5) {
+			continue
+		}
 		var isSet bool
 		for _, userMetadataPrefix := range userMetadataKeyPrefixes {
 			if !strings.HasPrefix(k, userMetadataPrefix) {

cmd/api-response.go

@@ -564,6 +564,10 @@ func generateListObjectsV2Response(bucket, prefix, token, nextToken, startAfter,
 					// values to client.
 					continue
 				}
+				// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+				if strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentLength) || strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentMD5) {
+					continue
+				}
 				content.UserMetadata[k] = v
 			}
 		}

cmd/crypto/header.go

@@ -21,6 +21,8 @@ import (
 	"encoding/json"
 	"net/http"
 	"strings"
+
+	xhttp "github.com/minio/minio/cmd/http"
 )
 
 // SSEHeader is the general AWS SSE HTTP header key.
@@ -81,6 +83,8 @@ const (
 func RemoveSensitiveHeaders(h http.Header) {
 	h.Del(SSECKey)
 	h.Del(SSECopyKey)
+	h.Del(xhttp.AmzMetaUnencryptedContentLength)
+	h.Del(xhttp.AmzMetaUnencryptedContentMD5)
 }
 
 // IsRequested returns true if the HTTP headers indicates

cmd/crypto/header_test.go

@@ -457,6 +457,16 @@ var removeSensitiveHeadersTests = []struct {
 			"X-Amz-Meta-Test-1": []string{"Test-1"},
 		},
 	},
+	{ // https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+		Header: http.Header{
+			"X-Amz-Meta-X-Amz-Unencrypted-Content-Md5":    []string{"value"},
+			"X-Amz-Meta-X-Amz-Unencrypted-Content-Length": []string{"value"},
+			"X-Amz-Meta-Test-1":                           []string{"Test-1"},
+		},
+		ExpectedHeader: http.Header{
+			"X-Amz-Meta-Test-1": []string{"Test-1"},
+		},
+	},
 }
 
 func TestRemoveSensitiveHeaders(t *testing.T) {

cmd/crypto/metadata.go

@@ -19,6 +19,7 @@ import (
 	"encoding/base64"
 	"errors"
 
+	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 )
 
@@ -38,6 +39,8 @@ func IsMultiPart(metadata map[string]string) bool {
 func RemoveSensitiveEntries(metadata map[string]string) { // The functions is tested in TestRemoveSensitiveHeaders for compatibility reasons
 	delete(metadata, SSECKey)
 	delete(metadata, SSECopyKey)
+	delete(metadata, xhttp.AmzMetaUnencryptedContentLength)
+	delete(metadata, xhttp.AmzMetaUnencryptedContentMD5)
 }
 
 // RemoveSSEHeaders removes all crypto-specific SSE

cmd/handler-utils.go

@@ -131,6 +131,13 @@ func extractMetadata(ctx context.Context, r *http.Request) (metadata map[string]
 		metadata[strings.ToLower(xhttp.ContentType)] = "application/octet-stream"
 	}
 
+	// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+	for k := range metadata {
+		if strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentLength) || strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentMD5) {
+			delete(metadata, k)
+		}
+	}
+
 	if contentEncoding, ok := metadata[strings.ToLower(xhttp.ContentEncoding)]; ok {
 		contentEncoding = trimAwsChunkedContentEncoding(contentEncoding)
 		if contentEncoding != "" {

cmd/http/headers.go

@@ -102,6 +102,9 @@ const (
 	AmzSecurityToken        = "X-Amz-Security-Token"
 	AmzDecodedContentLength = "X-Amz-Decoded-Content-Length"
 
+	AmzMetaUnencryptedContentLength = "X-Amz-Meta-X-Amz-Unencrypted-Content-Length"
+	AmzMetaUnencryptedContentMD5    = "X-Amz-Meta-X-Amz-Unencrypted-Content-Md5"
+
 	// Signature v2 related constants
 	AmzSignatureV2 = "Signature"
 	AmzAccessKeyID = "AWSAccessKeyId"

cmd/xl-storage-format-v2.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 )
 
@@ -397,6 +398,11 @@ func (j xlMetaV2Object) ToFileInfo(volume, path string) (FileInfo, error) {
 	}
 	fi.Metadata = make(map[string]string, len(j.MetaUser)+len(j.MetaSys))
 	for k, v := range j.MetaUser {
+		// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+		if strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentLength) || strings.EqualFold(k, xhttp.AmzMetaUnencryptedContentMD5) {
+			continue
+		}
+
 		fi.Metadata[k] = v
 	}
 	for k, v := range j.MetaSys {