moonlight-qt/nvpairingmanager.cpp

308 lines
11 KiB
C++

#include "nvpairingmanager.h"
#include "utils.h"
#include <QRandomGenerator>
#include <openssl/bio.h>
#include <openssl/aes.h>
#include <openssl/rand.h>
#include <openssl/pem.h>
#include <openssl/x509.h>
#include <openssl/evp.h>
NvPairingManager::NvPairingManager(QString address, IdentityManager im) :
m_Http(address, im),
m_Im(im)
{
QByteArray cert = m_Im.getCertificate();
BIO *bio = BIO_new_mem_buf(cert.data(), -1);
THROW_BAD_ALLOC_IF_NULL(bio);
m_Cert = PEM_read_bio_X509(bio, nullptr, nullptr, nullptr);
BIO_free_all(bio);
if (m_Cert == nullptr)
{
throw new std::runtime_error("Unable to load certificate");
}
QByteArray pk = m_Im.getPrivateKey();
bio = BIO_new_mem_buf(pk.data(), -1);
THROW_BAD_ALLOC_IF_NULL(bio);
m_PrivateKey = PEM_read_bio_PrivateKey(bio, nullptr, nullptr, nullptr);
BIO_free_all(bio);
if (m_PrivateKey == nullptr)
{
throw new std::runtime_error("Unable to load private key");
}
}
NvPairingManager::~NvPairingManager()
{
X509_free(m_Cert);
EVP_PKEY_free(m_PrivateKey);
}
QString
NvPairingManager::generatePinString()
{
return QString::asprintf("%04d", QRandomGenerator::global()->bounded(10000));
}
QByteArray
NvPairingManager::generateRandomBytes(int length)
{
char* data = static_cast<char*>(alloca(length));
RAND_bytes(reinterpret_cast<unsigned char*>(data), length);
return QByteArray(data, length);
}
QByteArray
NvPairingManager::encrypt(QByteArray plaintext, AES_KEY* key)
{
QByteArray ciphertext(plaintext.size(), 0);
for (int i = 0; i < plaintext.size(); i += 16)
{
AES_encrypt(reinterpret_cast<unsigned char*>(&plaintext.data()[i]),
reinterpret_cast<unsigned char*>(&ciphertext.data()[i]),
key);
}
return ciphertext;
}
QByteArray
NvPairingManager::decrypt(QByteArray ciphertext, AES_KEY* key)
{
QByteArray plaintext(ciphertext.size(), 0);
for (int i = 0; i < plaintext.size(); i += 16)
{
AES_decrypt(reinterpret_cast<unsigned char*>(&ciphertext.data()[i]),
reinterpret_cast<unsigned char*>(&plaintext.data()[i]),
key);
}
return plaintext;
}
QByteArray
NvPairingManager::getSignatureFromPemCert(QByteArray certificate)
{
BIO* bio = BIO_new_mem_buf(certificate.data(), -1);
THROW_BAD_ALLOC_IF_NULL(bio);
X509* cert = PEM_read_bio_X509(bio, nullptr, nullptr, nullptr);
BIO_free_all(bio);
ASN1_BIT_STRING* asnSignature;
X509_get0_signature(&asnSignature, NULL, cert);
QByteArray signature(reinterpret_cast<char*>(asnSignature->data), asnSignature->length);
X509_free(cert);
return signature;
}
bool
NvPairingManager::verifySignature(QByteArray data, QByteArray signature, QByteArray serverCertificate)
{
BIO* bio = BIO_new_mem_buf(serverCertificate.data(), -1);
THROW_BAD_ALLOC_IF_NULL(bio);
X509* cert = PEM_read_bio_X509(bio, nullptr, nullptr, nullptr);
BIO_free_all(bio);
EVP_PKEY* pubKey = X509_get_pubkey(cert);
THROW_BAD_ALLOC_IF_NULL(pubKey);
EVP_MD_CTX* mdctx = EVP_MD_CTX_create();
THROW_BAD_ALLOC_IF_NULL(mdctx);
EVP_DigestVerifyInit(mdctx, nullptr, EVP_sha256(), nullptr, pubKey);
EVP_DigestVerifyUpdate(mdctx, data.data(), data.length());
int result = EVP_DigestVerifyFinal(mdctx, reinterpret_cast<unsigned char*>(signature.data()), signature.length());
EVP_PKEY_free(pubKey);
EVP_MD_CTX_destroy(mdctx);
X509_free(cert);
return result > 0;
}
QByteArray
NvPairingManager::signMessage(QByteArray message)
{
EVP_MD_CTX *ctx = EVP_MD_CTX_create();
THROW_BAD_ALLOC_IF_NULL(ctx);
const EVP_MD *md = EVP_get_digestbyname("SHA256");
THROW_BAD_ALLOC_IF_NULL(md);
EVP_DigestInit_ex(ctx, md, NULL);
EVP_DigestSignInit(ctx, NULL, md, NULL, m_PrivateKey);
EVP_DigestSignUpdate(ctx, reinterpret_cast<unsigned char*>(message.data()), message.length());
size_t signatureLength = 0;
EVP_DigestSignFinal(ctx, NULL, &signatureLength);
QByteArray signature(signatureLength, 0);
EVP_DigestSignFinal(ctx, reinterpret_cast<unsigned char*>(signature.data()), &signatureLength);
EVP_MD_CTX_destroy(ctx);
return signature;
}
QByteArray
NvPairingManager::saltPin(QByteArray salt, QString pin)
{
return QByteArray().append(salt).append(pin.toLatin1());
}
NvPairingManager::PairState
NvPairingManager::pair(QString serverInfo, QString pin)
{
int serverMajorVersion = m_Http.getServerVersionQuad(serverInfo).at(0);
qDebug() << "Pairing with server generation: " << serverMajorVersion;
QCryptographicHash::Algorithm hashAlgo;
int hashLength;
if (serverMajorVersion >= 7)
{
// Gen 7+ uses SHA-256 hashing
hashAlgo = QCryptographicHash::Sha256;
hashLength = 32;
}
else
{
// Prior to Gen 7 uses SHA-1 hashing
hashAlgo = QCryptographicHash::Sha1;
hashLength = 20;
}
QByteArray salt = generateRandomBytes(16);
QByteArray saltedPin = saltPin(salt, pin);
AES_KEY encKey, decKey;
AES_set_decrypt_key(reinterpret_cast<const unsigned char*>(QCryptographicHash::hash(saltedPin, hashAlgo).data()), 128, &decKey);
AES_set_encrypt_key(reinterpret_cast<const unsigned char*>(QCryptographicHash::hash(saltedPin, hashAlgo).data()), 128, &encKey);
QString getCert = m_Http.openConnectionToString(m_Http.m_BaseUrlHttp,
"pair",
"devicename=roth&updateState=1&phrase=getservercert&salt=" +
salt.toHex() + "&clientcert=" + m_Im.getCertificate().toHex(),
false);
m_Http.verifyResponseStatus(getCert);
if (m_Http.getXmlString(getCert, "paired") != "1")
{
qDebug() << "Failed pairing at stage #1";
return PairState::FAILED;
}
QByteArray serverCert = m_Http.getXmlStringFromHex(getCert, "plaincert");
if (serverCert == nullptr)
{
qDebug() << "Server likely already pairing";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::ALREADY_IN_PROGRESS;
}
QByteArray randomChallenge = generateRandomBytes(16);
QByteArray encryptedChallenge = encrypt(randomChallenge, &encKey);
QString challengeXml = m_Http.openConnectionToString(m_Http.m_BaseUrlHttp,
"pair",
"devicename=roth&updateState=1&clientchallenge=" +
encryptedChallenge.toHex(),
true);
m_Http.verifyResponseStatus(challengeXml);
if (m_Http.getXmlString(challengeXml, "paired") != "1")
{
qDebug() << "Failed pairing at stage #2";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::FAILED;
}
QByteArray challengeResponseData = decrypt(m_Http.getXmlStringFromHex(challengeXml, "challengeresponse"), &decKey);
QByteArray clientSecretData = generateRandomBytes(16);
QByteArray challengeResponse;
QByteArray serverResponse(challengeResponseData.data(), hashLength);
ASN1_BIT_STRING* asnSignature;
X509_get0_signature(&asnSignature, NULL, m_Cert);
challengeResponse.append(challengeResponseData.data() + hashLength, 16);
challengeResponse.append(reinterpret_cast<char*>(asnSignature->data), asnSignature->length);
challengeResponse.append(clientSecretData);
QByteArray encryptedChallengeResponseHash = encrypt(QCryptographicHash::hash(challengeResponse, hashAlgo), &encKey);
QString respXml = m_Http.openConnectionToString(m_Http.m_BaseUrlHttp,
"pair",
"devicename=roth&updateState=1&serverchallengeresp=" +
encryptedChallengeResponseHash.toHex(),
true);
m_Http.verifyResponseStatus(respXml);
if (m_Http.getXmlString(respXml, "paired") != "1")
{
qDebug() << "Failed pairing at stage #3";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::FAILED;
}
QByteArray pairingSecret = m_Http.getXmlStringFromHex(respXml, "pairingsecret");
QByteArray serverSecret = QByteArray(pairingSecret.data(), 16);
QByteArray serverSignature = QByteArray(&pairingSecret.data()[16], 256);
if (!verifySignature(serverSecret,
serverSignature,
serverCert))
{
qDebug() << "MITM detected";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::FAILED;
}
QByteArray expectedResponseData;
expectedResponseData.append(randomChallenge);
expectedResponseData.append(getSignatureFromPemCert(serverCert));
expectedResponseData.append(serverSecret);
if (QCryptographicHash::hash(expectedResponseData, hashAlgo) != serverResponse)
{
qDebug() << "Incorrect PIN";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::PIN_WRONG;
}
QByteArray clientPairingSecret;
clientPairingSecret.append(clientSecretData);
clientPairingSecret.append(signMessage(clientSecretData));
QString secretRespXml = m_Http.openConnectionToString(m_Http.m_BaseUrlHttp,
"pair",
"devicename=roth&updateState=1&clientpairingsecret=" +
clientPairingSecret.toHex(),
true);
m_Http.verifyResponseStatus(secretRespXml);
if (m_Http.getXmlString(secretRespXml, "paired") != "1")
{
qDebug() << "Failed pairing at stage #4";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::FAILED;
}
QString pairChallengeXml = m_Http.openConnectionToString(m_Http.m_BaseUrlHttps,
"pair",
"devicename=roth&updateState=1&phase=pairchallenge",
true);
m_Http.verifyResponseStatus(pairChallengeXml);
if (m_Http.getXmlString(pairChallengeXml, "paired") != "1")
{
qDebug() << "Failed pairing at stage #5";
m_Http.openConnectionToString(m_Http.m_BaseUrlHttp, "unpair", nullptr, true);
return PairState::FAILED;
}
return PairState::PAIRED;
}