PolygonDLL/PolygonClientUtilities/Crypt.cpp

99 lines
2.6 KiB
C++

#include "pch.h"
#include "Crypt.h"
#include "Patches.h"
#include "Util.h"
Crypt__verifySignatureBase64_t Crypt__verifySignatureBase64 = (Crypt__verifySignatureBase64_t)ADDRESS_CRYPT__VERIFYSIGNATUREBASE64;
// Crypt::verifySignatureBase64(std::string message, std::string signatureBase64)
void __fastcall Crypt__verifySignatureBase64_hook(HCRYPTPROV* _this, void*, int a2, BYTE* pbData, int a4, int a5, int a6, DWORD dwDataLen, int a8, int a9, int a10, int a11, int a12, int a13, int a14, int a15)
{
/*
Ideally, we would be able to just use the function signature as-is.
However, it causes inexplicable crashes. Thus, we must reconstruct
the strings by hand given the manual parameters.
*/
std::string message;
std::string signatureBase64;
// Get message
const BYTE* v18 = pbData;
if ((unsigned int)a8 < 0x10)
{
v18 = (const BYTE*)&pbData;
}
message = std::string(reinterpret_cast<const char*>(pbData), dwDataLen);
// Get signatureBase64
int* v21 = (int*)a10;
if ((unsigned int)a15 < 0x10)
{
v21 = &a10;
}
signatureBase64 = std::string(reinterpret_cast<const char*>(v21), a14);
// Verify the signature
try
{
// Read public key
EVP_PKEY* key = NULL;
BIO* bio = BIO_new_mem_buf((void*)Util::publicKey.c_str(), Util::publicKey.length());
if (bio == NULL)
{
throw std::runtime_error("");
}
key = PEM_read_bio_PUBKEY(bio, NULL, NULL, NULL);
BIO_free(bio);
// Create context
EVP_PKEY_CTX* ctx = EVP_PKEY_CTX_new(key, NULL);
if (!ctx)
{
throw std::runtime_error("");
}
if (EVP_PKEY_verify_init(ctx) <= 0)
{
throw std::runtime_error("");
}
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
{
throw std::runtime_error("");
}
if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha1()) <= 0)
{
throw std::runtime_error("");
}
// Verify signature against the message
const char* signature = Util::base64Decode(signatureBase64).c_str();
const char* data = message.c_str();
int result = EVP_PKEY_verify(ctx, (unsigned char*)signature, strlen(signature), (unsigned char*)data, strlen(data));
// Dispose objects
EVP_PKEY_free(key);
EVP_PKEY_CTX_free(ctx);
delete signature;
delete data;
// Check
if (result != 1)
{
// throw std::runtime_error("");
}
}
catch (...)
{
throw std::runtime_error("");
}
}