Read / write credentials through CredRead and CredWrite, with a profile load for good measure. Fails under PowerShell remoting.

CredWriteAndReadWithProfileLoad.cpp

#include <SDKDDKVer.h>
#include <tchar.h>
#include <Windows.h>
#include <WinCred.h>
#include <Userenv.h>
#include <atlsecurity.h>
#include <Lmcons.h>

#include <iostream>

using namespace std;

template <typename T>
void CheckResult(T success, wchar_t const * const taskName)
{
	if (success)
		return;

	wcout << L"Failed to " << taskName << L": " << GetLastError();
	throw wstring(L"Failed to ") + taskName;
}

int wmain()
{
	wcout << L"Started." << endl;

	wchar_t userName[UNLEN + 1];
	DWORD bufferLength = sizeof(userName) / sizeof(userName[0]);
	CheckResult(GetUserName(userName, &bufferLength), L"get user name");

	wcout << L"User name = " << userName << endl;

	HANDLE hToken;
	CheckResult(OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &hToken), L"get thread token");

	wcout << L"Opened process token." << endl;

	PROFILEINFO profile = {};
	profile.dwSize = sizeof(profile);
	profile.lpUserName = userName;
	CheckResult(LoadUserProfile(hToken, &profile), L"load profile");

	wcout << L"Loaded user profile." << endl;

	wchar_t const target[] = L"TestCredentials";

	wchar_t const password[] = L"Password";
	CREDENTIALW credsToAdd = {};
	credsToAdd.Flags = 0;
	credsToAdd.Type = CRED_TYPE_GENERIC;
	credsToAdd.TargetName = const_cast<wchar_t*>(target);
	credsToAdd.CredentialBlob = (LPBYTE)&password;
	credsToAdd.CredentialBlobSize = sizeof(password);
	credsToAdd.Persist = CRED_PERSIST_LOCAL_MACHINE;
	CheckResult(CredWrite(&credsToAdd, 0), L"write credential");

	wcout << L"Wrote successfully." << endl;

	PCREDENTIALW creds;
	CheckResult(CredRead(target, 1, 0, &creds), L"read credential");

	wcout << L"Read successfully." << endl;

	wchar_t const * const passwordOut = (wchar_t const * const)creds->CredentialBlob;

	wcout << password << endl;
	wcout << passwordOut << endl;
	wcout << (wstring(password) == wstring(passwordOut) ? L"Success" : L"FAILURE") << endl;

	return 0;
}