IDENTITY_ATTRIBUTE_BLOB 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

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

Members

Member	Description
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. Therefore, 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.

Sample

The following example illustrates several basic steps, which eventually result in a populated IDENTITY_ATTRIBUTE_BLOB structure:

1. Obtain an IReferenceIdentity for the assembly.

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

3. Create a character buffer, and cast it as an IDENTITY_ATTRIBUTE_BLOB structure.

4. Call the CurrentIntoBuffer method of the IEnumIDENTITY_ATTRIBUTE interface. This method copies the attributes Namespace, Name, and Value into the character buffer. The three offsets to those strings will become available in the IDENTITY_ATTRIBUTE_BLOB structure.

// 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;
}

To 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: See .NET Framework System Requirements.

Header: Isolation.h

.NET Framework Versions: 3.5 SP1, 3.5, 3.0 SP1, 3.0, 2.0 SP1, 2.0

See Also

Reference

IReferenceIdentity Interface

IEnumIDENTITY_ATTRIBUTE Interface

IDENTITY_ATTRIBUTE Structure

Other Resources

Fusion Structures