{
			authT: authTypePresigned,
			pass:  true,
		},
		// Test 3 - supported s3 type signed.
		{
			authT: authTypeSigned,
			pass:  true,
		},
		// Test 4 - supported s3 type with post policy.
		{
			authT: authTypePostPolicy,
			pass:  true,
		},
		// Test 5 - supported s3 type with streaming signed.
		{
			authT: authTypeStreamingSigned,
			pass:  true,
		},

		return "", ErrMissingSignTag
	}
	if signFields[1] == "" {
		return "", ErrMissingFields
	}
	signature := signFields[1]
	return signature, ErrNone
}

// Parse slice of signed headers from signed headers tag.
func parseSignedHeader(signedHdrElement string) ([]string, APIErrorCode) {
	signedHdrFields := strings.Split(strings.TrimSpace(signedHdrElement), "=")
	if len(signedHdrFields) != 2 {

		// TODO: https://github.com/istio/istio/issues/41937
		grpc.WithTransportCredentials(credentials.NewTLS(
			&tls.Config{
				// Always skip verifying, because without it we always get "certificate signed by unknown authority".
				// We don't set the XDSSAN for the same reason.
				InsecureSkipVerify: true,
			})),
		grpc.WithPerRPCCredentials(k8sCreds),
	}, nil

			partNumberMarker: "",
			maxParts:         "",
			expectedErr:      noSuchUploadErr,
		},
	}

	// string to represent V2 signed HTTP request.
	reqV2Str := "V2 Signed HTTP request"
	// string to represent V4 signed HTTP request.
	reqV4Str := "V4 Signed HTTP request"
	// Collection of HTTP request and ResponseRecorder and request type string.
	type inputReqRec struct {
		req     *http.Request

	if payload != req.Header.Get(xhttp.AmzContentSha256) {
		return cred, "", "", time.Time{}, ErrContentSHA256Mismatch
	}

	// Extract all the signed headers along with its values.
	extractedSignedHeaders, errCode := extractSignedHeaders(signV4Values.SignedHeaders, r)
	if errCode != ErrNone {
		return cred, "", "", time.Time{}, errCode
	}

}

func getReqAccessKeyV2(r *http.Request) (auth.Credentials, bool, APIErrorCode) {
	if accessKey := r.Form.Get(xhttp.AmzAccessKeyID); accessKey != "" {
		return checkKeyValid(r, accessKey)
	}

	// below is V2 Signed Auth header format, splitting on `space` (after the `AWS` string).
	// Authorization = "AWS" + " " + AWSAccessKeyId + ":" + Signature
	authFields := strings.Split(r.Header.Get(xhttp.Authorization), " ")
	if len(authFields) != 2 {

	if err != nil {
		// The kernel can return valid but non integer values
		// but still, no need to interpret more
		return 0
	}
	if limit == cgroupMemNoLimit {
		// No limit set, It's the highest positive signed 64-bit
		// integer (2^63-1), rounded down to multiples of 4096 (2^12),
		// the most common page size on x86 systems - for cgroup_limits.
		return 0
	}
	return limit
}

func availableMemory() (available uint64) {

				t.Errorf("Test %d: Parsed Signature field mismatch: Expected \"%s\", got \"%s\"", i+1, testCase.expectedAuthField.Signature, parsedAuthField.Signature)
			}

			// validating the extracted signed headers.
			if strings.Join(testCase.expectedAuthField.SignedHeaders, ",") != strings.Join(parsedAuthField.SignedHeaders, ",") {

			t.Align = c.ptrSize
		}
		t.C.Set("enum " + dt.EnumName)
		signed := 0
		t.EnumValues = make(map[string]int64)
		for _, ev := range dt.Val {
			t.EnumValues[ev.Name] = ev.Val
			if ev.Val < 0 {
				signed = signedDelta
			}
		}
		switch t.Size + int64(signed) {
		default:
			fatalf("%s: unexpected: %d-byte enum type - %s", lineno(pos), t.Size, dtype)
		case 1:

// getSignature final signature in hexadecimal form.
func getSignature(signingKey []byte, stringToSign string) string {
	return hex.EncodeToString(sumHMAC(signingKey, []byte(stringToSign)))
}

// Check to see if Policy is signed correctly.
func doesPolicySignatureMatch(formValues http.Header) (auth.Credentials, APIErrorCode) {
	// For SignV2 - Signature field will be valid
	if _, ok := formValues[xhttp.AmzSignatureV2]; ok {