msasn1
msasn1.dll is the Microsoft asn.1 encoding/decoding library. It's used by native crypt32.dll, wintrust.dll, and other Microsoft dlls. As far as I know, no application uses it directly. It used to be undocumented, but recent platform SDKs have included the msasn1.h header file. Using this, it should be possible to implement it, and avoid code duplication by using it in Wine's crypt32.dll and wintrust.dll. It's still pretty low priority though.