C# MD5 and SHA1 encrypt

MD5_SHA1_encrypt.cs

// MD5
public static string Md5(string str)
{
    var algorithm = HashAlgorithmNames.Md5;
    HashAlgorithmProvider provider = HashAlgorithmProvider.OpenAlgorithm(algorithm);
    var hash = provider.CreateHash();
    IBuffer buffer = CryptographicBuffer.ConvertStringToBinary(str, BinaryStringEncoding.Utf16LE);
    hash.Append(buffer);
    var hashedBuffer = hash.GetValueAndReset();
    return CryptographicBuffer.ConvertBinaryToString(BinaryStringEncoding.Utf16LE, hashedBuffer);
}

// SHA1
public static string Sha1(string str)
{
    var algorithm = HashAlgorithmNames.Sha1;
    HashAlgorithmProvider provider = HashAlgorithmProvider.OpenAlgorithm(algorithm);
    var hash = provider.CreateHash();
    IBuffer buffer = CryptographicBuffer.ConvertStringToBinary(str, BinaryStringEncoding.Utf8);
    hash.Append(buffer);
    var hashedBuffer = hash.GetValueAndReset();
    return CryptographicBuffer.EncodeToHexString(hashedBuffer);
}