[Bug 17760] New: CryptAcquireContext: Use MS_ENHANCED_PROV instead of MS_DEF_PROV when pszProvider == NULL

http://bugs.winehq.org/show_bug.cgi?id=17760

Summary: CryptAcquireContext: Use MS_ENHANCED_PROV instead of
                    MS_DEF_PROV when pszProvider == NULL
           Product: Wine
           Version: 1.1.17
          Platform: All
        OS/Version: All
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: crypt32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

If the pszProvider parameter in the CryptAcquireContext function is NULL Wine
seems to use the MS_DEF_PROV provider (Base) by default. However on Windows (at
least XP and higher) the default provider depends on many factors (e.g.
registry) and by default (see Note 1) the MS_ENHANCED_PROV or a newer/stronger
provider is selected.

The result is that applications that use CryptAcquireContext with a NULL
pszProvider parameter assume that a Strong or better provider is selected and
therefore fail under Wine if they use an algorithm (or keylen) that is not
supported by the Base provider.

I strongly recommend to use the Strong/Enhanced provider in this case.

Note 1
======
"When an application calls CryptAcquireContext and specifies a provider type
but no provider name, the function looks for a named provider, first checking a
list of default named providers associated with the logged-on user and, if that
fails, from a list of default named providers associated with the computer.
After the provider name has been determined, the CryptAcquireContext function
searches for the CSP for that provider, loads it, and returns its handle."
Reference: http://msdn.microsoft.com/en-us/library/aa380246(VS.85).aspx