Hi group,

I'm trying to encrypt & then decrypt a string using symmetric
encryption. The encryption seems to work fine, but when trying to
decrypt, I get a System.IndexOutOfRangeException. Please would someone
be kind enough to point out my mistake? Please see my code (C++/CLI)
below.

TIA,
Ralph

System::String^ Quantum::Util::EncryptString(System::String^ str)
{
    using namespace System::IO;
    using namespace System::Security::Cryptography;

    MemoryStream^ ms = gcnew MemoryStream;
    RijndaelManaged^ rm = gcnew RijndaelManaged;
    CryptoStream^ cs = gcnew CryptoStream(ms, rm->CreateEncryptor(m_key, m_iv),
        CryptoStreamMode::Write);
    StreamWriter^ sw = gcnew StreamWriter(cs);
   
    try {
        sw->Write(str);
    } finally {
        sw->Close();
        cs->Close();
        ms->Close();
    }

    return System::Convert::ToBase64String(ms->ToArray());
}

System::String^ Quantum::Util::DecryptString(System::String^ str)
{
    using namespace System::IO;
    using namespace System::Security::Cryptography;

    MemoryStream^ ms = gcnew MemoryStream;
    RijndaelManaged^ rm = gcnew RijndaelManaged;
    CryptoStream^ cs = gcnew CryptoStream(ms, rm->CreateDecryptor(m_key, m_iv),
        CryptoStreamMode::Read);
    StreamWriter^ sw = gcnew StreamWriter(ms);
    StreamReader^ sr = gcnew StreamReader(cs);

    System::String^ cleartext;
    try {
        array<System::Byte>^ bytes = System::Convert::FromBase64String(str);
        sw->Write(bytes);
        cleartext = sr->ReadToEnd();
    } finally {
        sw->Close();
        sr->Close();
        cs->Close();
        ms->Close();
    }

    return cleartext;
}