IDENTITY_ATTRIBUTE_BLOB Structure

This Fusion structure contains information about a single attribute in an assembly, and consists of three DWORDs. Each DWORD is an offset into a character buffer produced by the CurrentIntoBuffer method of the IEnumIDENTITY_ATTRIBUTE Interface interface

typedef struct _IDENTITY_ATTRIBUTE_BLOB {
    DWORD  ofsNamespace;
    DWORD  ofsName;
    DWORD  ofsValue;
}   IDENTITY_ATTRIBUTE_BLOB;

Parameters

• ofsNamespace
  The first offset into the character buffer. This offset IS NOT followed by the attribute's Namespace, but by a series of null characters. As such, it is not used.

• ofsName
  The second offset into the character buffer. This location marks the start of the attribute's Name.

• ofsValue
  The third offset into the character buffer. This location marks the start of the attribute's Value.

Remarks

An IDENTITY_ATTRIBUTE_BLOB consists of three offsets into a character buffer.

Sample

The following code illustrates several basic steps which eventually result in a populated IDENTITY_ATTRIBUTE_BLOB.

1. Obtain an IReferenceIdentity Interface interface for the assembly.

2. Call the IReferenceIdentity::EnumAttributes method and obtain an IEnumIDENTITY_ATTRIBUTE Interface.

3. Cast the character buffer as an IDENTITY_ATTRIBUTE_BLOB.

4. Call the CurrentIntoBuffer method of the IEnumIDENTITY_ATTRIBUTE interface. This will load the first three strings into the character buffer.

5. The three offsets to those strings are now available in the IDENTITY_ATTRIBUTE_BLOB.

// EnumAssemblyAttributes.cpp : main project file.

#include "stdafx.h"

#include "fusion.h"
#include "windows.h"
#include "stdio.h"
#include "mscoree.h"
#include "isolation.h"

typedef HRESULT (__stdcall *PFNGETREF)(LPCWSTR pwzFile, REFIID riid, IUnknown **ppUnk);
typedef HRESULT (__stdcall *PFNGETAUTH)(IIdentityAuthority **ppIIdentityAuthority);

PFNGETREF                   g_pfnGetAssemblyIdentityFromFile = NULL;
PFNGETAUTH                  g_pfnGetIdentityAuthority = NULL;
IUnknown                    *g_pUnk = NULL;

bool Init()
{
    HRESULT     hr = S_OK;
    DWORD       dwSize = 0;
    bool        bRC = false;
    
    hr = CorBindToRuntimeEx(NULL, L"wks", 0, CLSID_CorRuntimeHost,
                           IID_ICorRuntimeHost, (void **)&g_pUnk);
    if(FAILED(hr)) {
        printf("Error: Failed to initialize CLR runtime! hr = 0x%0x\n",
                hr);
        goto Exit;
    }
   
    if (SUCCEEDED(hr)) {
        hr = GetRealProcAddress("GetAssemblyIdentityFromFile",
                         (VOID **)&g_pfnGetAssemblyIdentityFromFile);
    }

    if (SUCCEEDED(hr)) {
        hr = GetRealProcAddress("GetIdentityAuthority",
                                (VOID **)&g_pfnGetIdentityAuthority);
    }

    if (!g_pfnGetAssemblyIdentityFromFile || 
        !g_pfnGetIdentityAuthority)
    {
        printf("Error: Cannot get required APIs from fusion.dll!\n");
        goto Exit;
    }

    bRC = true;

Exit:
    return bRC;
}

void Shutdown()
{
    if(g_pUnk) {
        g_pUnk->Release();
        g_pUnk = NULL;
    }
}

void Usage()
{
    printf("EnumAssemblyAttributes: A tool to enumerate the identity 
            attributes of a given assembly.\n\n");
    printf("Usage: EnumAssemblyAttributes AssemblyFilePath\n");
    printf("\n");
}

int _cdecl wmain(int argc, LPCWSTR argv[])
{
    int     iResult = 1;
    IUnknown                    *pUnk  = NULL;
    IReferenceIdentity          *pRef  = NULL;
    HRESULT                     hr     = S_OK;   
    IEnumIDENTITY_ATTRIBUTE     *pEnum = NULL;
    BYTE                        abData[1024];
    DWORD                       cbAvailable;
    DWORD                       cbUsed;
    IDENTITY_ATTRIBUTE_BLOB     *pBlob;

    if(argc != 2) {
        Usage();
        goto Exit;
    }

    if(!Init()) {
        printf("Failure initializing EnumIdAttr.\n");
        goto Exit;
    }

    hr = g_pfnGetAssemblyIdentityFromFile(argv[1], 
                            __uuidof(IReferenceIdentity), &pUnk);

    if (FAILED(hr)) {
        printf("GetAssemblyIdentityFromFile failed with hr = 0x%x", 
                hr);
        goto Exit;
    }

    hr = pUnk->QueryInterface(__uuidof(IReferenceIdentity), 
                              (void**)&pRef);
    if (FAILED(hr)) {
        goto Exit;
    }

    hr = pRef->EnumAttributes(&pEnum);
    if (FAILED(hr)) {
        printf("IReferenceIdentity::EnumAttributes failed with hr = 
                0x%x", hr);
        goto Exit;
    }

    pBlob = (IDENTITY_ATTRIBUTE_BLOB *)(abData);
    while (1) {
        cbAvailable = sizeof(abData);
        hr = pEnum->CurrentIntoBuffer(cbAvailable, abData, &cbUsed);
        if (FAILED(hr)) {
            printf("IEnumIDENTITY_ATTRIBUTE::CurrentIntoBuffer failed 
                    with hr = 0x%x", hr);
            goto Exit;
        }

        if (! cbUsed) {
            break;
        }

        LPWSTR pwzNameSpace = (LPWSTR)(abData + pBlob->ofsNamespace);
        LPWSTR pwzName      = (LPWSTR)(abData + pBlob->ofsName);
        LPWSTR pwzValue     = (LPWSTR)(abData + pBlob->ofsValue);
        printf("%ws: %ws = %ws\n", pwzNameSpace, pwzName, pwzValue);

        hr = pEnum->Skip(1);
        if (FAILED(hr)) {
            printf("IEnumIDENTITY_ATTRIBUTE::Skip failed with hr = 
                    0x%x", hr);
            goto Exit;
        }
    }

    iResult = 0;

Exit:

    Shutdown();

    if (pUnk) {
        pUnk->Release();
    }

    if (pRef) {
        pRef->Release();
    }

    if (pEnum) {
        pEnum->Release();
    }

    return iResult;
}

Run the sample:

C:\> EnumAssemblyAttributes.exe C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.dll

Sample output:

Culture = neutral

name = System

processorArchitecture = MSIL

PublicKeyToken = b77a5c561934e089

Version = 2.0.0.0

Requirements

Platforms: Windows 2000, Windows XP, Windows Server 2003 family

Header: Isolation.h

.NET Framework Version: 2.0

See Also

Reference

IReferenceIdentity Interface
IEnumIDENTITY_ATTRIBUTE Interface
IDENTITY_ATTRIBUTE Structure

Other Resources

Fusion Structures
Structures (Unmanaged API Reference)