Hi!

It's not acutally too hard. It's just that the documentation isn't
exactly great. Always look in the docs for the raw Win32 APIs.

First you need to initialize the Crypto API and select
the appropriate CSP.

CCryptProv prov;
CheckHresult( prov.Initialize() );

I'm not sure that is really what you want. Typically, you would derive
the key from a hash of the password not from the raw password.

This would probably look like
System::Byte key[] = new PasswordDeriveBytes(
   Convert::FromBase64String("password"), salt )
       ->CryptDeriveKey("TripleDES", "SHA1", 192, IV );

Not exactly certain (looks like the documentation is pretty poor here)
I guess - quite contrary to the docs --, salt isn't used at all here and IV
receives the initialization vector. Haven't tried it, though.

If you want it that way, you should use CCryptDerivedKey. Otherwise
(the key is a raw password) you need to use CCryptImportKey.

To construct the CCryptDerivedKey you need a hash of the
key. You get that from the corresponding CCryptXXXHash class.

E.g.:
CCryptSHA1Hash hash;
CheckHresult( hash.Initialize(prov), password );
CCryptDerivedKey key;
CheckHresult( key.Initialize(prov, hash, CALG_3DES ) );

key.Encrypt( ... );

Base64 encoding is also supported by the ATL Server libs.
Look for Base64(En/De)code.

-hg