AES key max-size 32?

[Behrens, Meike]

Hello,

I am currently working at symmetric e- and decryption with the aes -
stuff. When I tried to ?verify? The Key with my generated Initalisation
Vector I get some exceptions. (key Size about 1024 and IV-Size =
AES::BLOCKSIZE, should be 16 at the Moment). When I reduce the key-size
to 32 everything works. Everything above doesnt work. It compiles but
throws exceptions. 

This is my current code: 

td::string CCryptoBase::SymmEncryptByte( const byte* data, const
unsigned int data_size, const char * key ){
        std::string output;

        const unsigned int block_size=CryptoPP::AES::BLOCKSIZE;
        bytestring out;
        // Generate IV
        byte iv[block_size];
        AutoSeededRandomPool rng;
        rng.GenerateBlock(/*(byte*)&*/iv,block_size);
        // Extract the key
        StringSource keyString(key,true,new HexDecoder);
        SecByteBlock keyByte(keyString.MaxRetrievable());
        keyString.Get(keyByte,keyByte.size());
        // Create encryptor
        CFB_Mode<AES>::Encryption
cfbEncryption(keyByte.data(),keyByte.size(),iv); <------ zhis throws the
exception
        
        StringSource encryptor(data,data_size,true,new Gzip(new
StreamTransformationFilter(cfbEncryption, new
StringSinkTemplate<bytestring>(out) )));
        out.append(iv,block_size);
        out.append((byte*)&block_size,sizeof(block_size));

        HexEncoder he(new StringSink(output));
        he.Put(out.c_str(),out.size(),true);
        he.MessageEnd();
        return output;
}



Has someone any hint for me? Thanks, 

Meike