Don't be helpless: You can find information, too, if you try

Raymond Chen

June 13th, 20080 0

Here’s a question that floated past my view:

Anybody know if there exists a library for computing MD5 hashes from unmanaged code? MSDN has information about .NET classes, but nothing about the unmanaged side.

Hm, let’s see.

C:\Windows SDK\Include> grep MD5 *.h
wincrypt.h:#define ALG_SID_MD5                     3
wincrypt.h:#define ALG_SID_SSL3SHAMD5              8
wincrypt.h:#define CALG_MD5                (ALG_CLASS_HASH | ALG_TYPE_ANY | ALG_SID_MD5)
wincrypt.h:#define CALG_HUGHES_MD5         (ALG_CLASS_KEY_EXCHANGE|ALG_TYPE_ANY|ALG_SID_MD5)
wincrypt.h:#define CALG_SSL3_SHAMD5        (ALG_CLASS_HASH | ALG_TYPE_ANY | ALG_SID_SSL3SHAMD5)
wincrypt.h:#define KP_PRECOMP_MD5          24
wincrypt.h:#define szOID_RSA_MD5RSA        "1.2.840.113549.1.1.4"
wincrypt.h:#define szOID_RSA_MD5           "1.2.840.113549.2.5"

Wow, those hits sure look promising. Perhaps a search on Windows Live or Google¹ will turn up something. Oh hey, how about that, sample code.

Exercise: Use this exact same technique to answer this commenter’s question on how the C# ++ operator works. Hint: Since this is a question about the C# language, the C# language specification would be a good starting point.

Exercise: Use this technique to answer this commenter’s question on how to connect to a process as a debugger.

Footnotes

¹ OH MY GOD I LINKED TO GOOGLE.