return ch, ErrCredMalformed
	}
	accessKey := strings.Join(credElements[:len(credElements)-4], SlashSeparator) // The access key may contain one or more `/`
	if !auth.IsAccessKeyValid(accessKey) {
		return ch, ErrInvalidAccessKeyID
	}
	// Save access key id.
	cred := credentialHeader{
		accessKey: accessKey,
	}
	credElements = credElements[len(credElements)-4:]
	var e error
	cred.scope.date, e = time.Parse(yyyymmdd, credElements[0])

		{
			inputCredentialStr: generateCredentialStr(
				"^#",
				UTCNow().Format(yyyymmdd),
				"ABCD",
				"ABCD",
				"ABCD"),
			expectedCredentials: credentialHeader{},
			expectedErrCode:     ErrInvalidAccessKeyID,
		},
		// Test Case - 5.
		// Test case with invalid date format date.
		// a valid date format for credentials is "yyyymmdd".
		{
			inputCredentialStr: generateCredentialStr(