var stringTests = []struct {
	ETag   ETag
	String string
}{
	{ETag: ETag{59, 131, 239, 150, 56, 127, 20, 101}, String: "3b83ef96387f1465"},                                                                  // 0
	{ETag: ETag{59, 131, 239, 150, 56, 127, 20, 101, 95, 200, 84, 221, 195, 198, 189, 87}, String: "3b83ef96387f14655fc854ddc3c6bd57"},             // 1

// generates CopyObjectResponse from etag and lastModified time.
func generateCopyObjectResponse(etag string, lastModified time.Time) CopyObjectResponse {
	return CopyObjectResponse{
		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

// generates CopyObjectPartResponse from etag and lastModified time.

		// This should fail even without quorum issues, but with quorum failure
		// we can't verify the ETag at all.
		opts := ObjectOptions{
			UserDefined: map[string]string{
				xhttp.IfMatch: "wrong-etag-12345",
			},
			HasIfMatch: true,
			CheckPrecondFn: func(oi ObjectInfo) bool {
				// Precondition fails if ETags don't match
				return oi.ETag != "wrong-etag-12345"
			},
		}

		ETag:       "",
		ShouldFail: true, // ETag prefix is not a valid hex value
	},
	{
		ObjectKey:  [32]byte{},
		ObjectInfo: ObjectInfo{ETag: "16516b396f0f4d4f2a0e7177557bec4-1-2"},
		ETag:       "",
		ShouldFail: true, // ETag contains multiple: -
	},
}

func TestDecryptETag(t *testing.T) {
	for i, test := range decryptETagTests {

				PartNumber: part.PartNumber,
				GotETag:    part.ETag,
			}
			return oi, invp
		}
		expPart := currentFI.Parts[partIdx]

		// ensure that part ETag is canonicalized to strip off extraneous quotes
		part.ETag = canonicalizeETag(part.ETag)
		expETag := tryDecryptETag(objectEncryptionKey, expPart.ETag, kind == crypto.S3)
		if expETag != part.ETag {
			invp := InvalidPart{
				PartNumber: part.PartNumber,

		etag = commonETag(etags, quorum)

		if etag != "" { // allow this fallback only if a non-empty etag is found.
			for index, e := range etags {
				if partsMetadata[index].IsValid() && e == etag {
					onlineDisks[index] = disks[index]
				} else {
					onlineDisks[index] = nil
				}
			}
			return onlineDisks, modTime, etag
		}
	}

		return
	}

	etag := getDecryptedETag(formValues, objInfo, false)

	// We must not use the http.Header().Set method here because some (broken)
	// clients expect the ETag header key to be literally "ETag" - not "Etag" (case-sensitive).
	// Therefore, we have to set the ETag directly as map entry.
	w.Header()[xhttp.ETag] = []string{`"` + etag + `"`}

		// Test Case 3: if-match with wrong ETag
		// Even if the ETag doesn't match, we should still get read quorum error
		// because we can't read the object to check the condition.
		opts := ObjectOptions{
			UserDefined: map[string]string{
				xhttp.IfMatch: "wrong-etag",
			},
			CheckPrecondFn: func(oi ObjectInfo) bool {
				// Precondition fails if ETag doesn't match

	return partKey
}

// SealETag seals the etag using the object key.
// It does not encrypt empty ETags because such ETags indicate
// that the S3 client hasn't sent an ETag = MD5(object) and
// the backend can pick an ETag value.
func (key ObjectKey) SealETag(etag []byte) []byte {
	if len(etag) == 0 { // don't encrypt empty ETag - only if client sent ETag = MD5(object)
		return etag
	}
	var buffer bytes.Buffer

	for i := range key {
		key[i] = byte(i)
	}
	for i, etag := range sealUnsealETagTests {
		tag, err := hex.DecodeString(etag)
		if err != nil {
			t.Errorf("Test %d: failed to decode etag: %s", i, err)
		}
		sealedETag := key.SealETag(tag)
		unsealedETag, err := key.UnsealETag(sealedETag)
		if err != nil {
			t.Errorf("Test %d: failed to decrypt etag: %s", i, err)
		}
		if !bytes.Equal(unsealedETag, tag) {