帮助CredEnumerate

Question

作为这个问题的后续,我希望有人可以帮助CredEnumerate API.

据我从文档中了解,PCREDENTIALS out参数是"指向凭证指针数组的指针".我能够使用C#成功调用CredEnumerate API,但我不确定如何将PCREDENTIALS转换为有用的东西(如凭证列表).

编辑:这是我正在使用的代码:

        int count = 0;
        IntPtr pCredentials = IntPtr.Zero;
        bool ret = false;
        ret = CredEnumerate(null, 0, out count, out pCredentials);
        if (ret != false)
        {
            IntPtr[] credentials = new IntPtr[count];
            IntPtr p = pCredentials;
            for (int i = 0; i < count; i++)
            {
                p = new IntPtr(p.ToInt32() + i);
                credentials[i] = Marshal.ReadIntPtr(p);
            }
            List<Credential> creds = new List<Credential>(credentials.Length);
            foreach (IntPtr ptr in credentials)
            {
                creds.Add((Credential)Marshal.PtrToStructure(ptr, typeof(Credential)));
            }
        }

不幸的是,虽然这适用于阵列中的第一个凭证 - 它会被生成并正确地添加到列表中 - 随后的数组项目会在Marshal.PtrToStructure上轰炸,并出现以下错误:

尝试读取或写入受保护的内存.这通常表明其他内存已损坏.

有任何想法吗？任何人？Bueller？

Answer 1

您需要取消引用指向数组的指针才能获取数组,然后对于数组中的每个项目,您需要取消引用该项以获取PCREDENTIALS实例.

我发现这篇文章带有一些示例代码,用于执行您想要执行的操作:

[DllImport("advapi32", SetLastError = true, CharSet=CharSet.Unicode)]
static extern bool CredEnumerate(string filter, int flag, out int count, out IntPtr
pCredentials);

...

int count = 0;
IntPtr pCredentials = IntPtr.Zero;
IntPtr[] credentials = null;
bool ret = CredEnumerate(null, 0, out count, out pCredentials);
if (ret != false)
{
    credentials = new IntPtr[count];
    IntPtr p = pCredentials;
    for (int n = 0; n < count; n++)
    {
        credentials[n] = Marshal.ReadIntPtr(pCredentials,
           n * Marshal.SizeOf(typeof(IntPtr)));
    }
} 
else
// failed....

然后对于每个指针,您需要使用它Marshal.PtrToStructure来将指针解引用到PCREDENTIALS结构实例中(抱歉,我找不到PCREDENTIALS任何地方的typedef ,我假设你拥有它 - 如果你确实没有忘记正确的MarshalAs属性和StructLayout你定义它时的属性):

// assuming you have declared struct PCREDENTIALS
var creds = new List<PCREDENTIALS>(credentials.Length);
foreach (var ptr in credentials)
{
    creds.Add((PCREDENTIALS)Marshal.PtrToStructure(ptr, typeof(PCREDENTIALS)));
}

您显然希望将示例和PtrToStructure代码结合起来以获得最佳结果,但我希望保持示例的完整性.