crypt_destroy_key_test.cpp

#define _CRT_SECURE_NO_WARNINGS

#include "targetver.h"

#include <stdio.h>
#include <tchar.h>

#include <Windows.h>
#include <Wincrypt.h>

#include <string.h>

#define USER_RSA_KEY_LEN 2048 // 2048-bit


void dump_hex(const char* Name, BYTE const* Data, size_t const Len)
{
	printf("%s:", Name);
	for (size_t i = 0; i < Len; ++i) {
		if ((i % 16 == 0)) {
			printf("\n");
		}
		printf("%02X ", Data[i]);

	}
	printf("\n====\n");
}
int main()
{
	HCRYPTPROV prov;
	HCRYPTKEY keyUser;
	if (!CryptAcquireContext(&prov,
		NULL, MS_ENH_RSA_AES_PROV, PROV_RSA_AES,
		CRYPT_VERIFYCONTEXT)) {
		puts("error CryptAcquireContext");
		return 1;
	}
	if (!CryptGenKey(prov, AT_KEYEXCHANGE,
		(USER_RSA_KEY_LEN << 16) | CRYPT_EXPORTABLE, &keyUser)) {
		puts("error CryptGenKey");
		return 1;
	}
	BYTE keyData[4096];
	memset(keyData, 0xFE, sizeof(keyData));
	DWORD len = 4096;
	if (!CryptExportKey(keyUser, 0, PRIVATEKEYBLOB, 0, &keyData[0], &len)) {
		printf("error export!\n");
		return 1;
	}

	size_t idx = 0;
	dump_hex("blob_header", &keyData[idx], 8);
	idx += 8;
	dump_hex("pub_key", &keyData[idx], 12);
	idx += 12;
	DWORD keyLen = *(((DWORD*)keyData) + 3) / 8;
	DWORD subKeyLen = (keyLen + 1) / 2;
	printf("Keylen: %d\n", keyLen);
	dump_hex("N", &keyData[idx], keyLen);
	idx += keyLen;
	dump_hex("p", &keyData[idx], subKeyLen);
	idx += subKeyLen;
	dump_hex("q", &keyData[idx], subKeyLen);


	printf("\n%p %p\n", keyData, keyData+4096);
	printf("Key generated, press enter to zero export\n");
	getchar();
	SecureZeroMemory(keyData, 4096);

	printf("Key generated, press enter to 'destroy' it\n");
	getchar();

	CryptDestroyKey(keyUser);
	printf("Key destroyed!\n");

	printf("hKey: %p\n", keyUser);

	getchar();
    return 0;
}