Revision control
Copy as Markdown
// Copyright (C) 2015 Mikkel Krautz <mikkel@krautz.dk>
// Copyright (C) 2016 Richard J. Moore <rich@kde.org>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:cryptography
#include "qsslsocket_openssl_symbols_p.h"
#include "qtlsbackend_openssl_p.h"
#include <QtNetwork/private/qsslsocket_p.h>
#include <QtCore/qscopeguard.h>
#include <QtCore/qbytearray.h>
#include <QtCore/qiodevice.h>
#include <QtCore/qdebug.h>
#include <openssl/bn.h>
#include <openssl/dh.h>
QT_BEGIN_NAMESPACE
#ifndef OPENSSL_NO_DEPRECATED_3_0
namespace {
bool isSafeDH(DH *dh)
{
int status = 0;
int bad = 0;
// TLSTODO: check it's needed or if supportsSsl()
// is enough.
QSslSocketPrivate::ensureInitialized();
//
// The additional call to BN_mod_word(dh->p, 24)
// (and unmasking of DH_NOT_SUITABLE_GENERATOR)
// is performed to ensure your program accepts
// IETF group parameters. OpenSSL checks the prime
// is congruent to 11 when g = 2; while the IETF's
// primes are congruent to 23 when g = 2.
// Without the test, the IETF parameters would
// fail validation. For details, see Diffie-Hellman
// Parameter Check (when g = 2, must p mod 24 == 11?).
// Mark p < 1024 bits as unsafe.
if (q_DH_bits(dh) < 1024)
return false;
if (q_DH_check(dh, &status) != 1)
return false;
const BIGNUM *p = nullptr;
const BIGNUM *q = nullptr;
const BIGNUM *g = nullptr;
q_DH_get0_pqg(dh, &p, &q, &g);
if (q_BN_is_word(const_cast<BIGNUM *>(g), DH_GENERATOR_2)) {
const unsigned long residue = q_BN_mod_word(p, 24);
if (residue == 11 || residue == 23)
status &= ~DH_NOT_SUITABLE_GENERATOR;
}
bad |= DH_CHECK_P_NOT_PRIME;
bad |= DH_CHECK_P_NOT_SAFE_PRIME;
bad |= DH_NOT_SUITABLE_GENERATOR;
return !(status & bad);
}
} // unnamed namespace
#endif
int QTlsBackendOpenSSL::dhParametersFromDer(const QByteArray &der, QByteArray *derData) const
{
#ifndef OPENSSL_NO_DEPRECATED_3_0
Q_ASSERT(derData);
if (der.isEmpty())
return DHParams::InvalidInputDataError;
const unsigned char *data = reinterpret_cast<const unsigned char *>(der.data());
const int len = der.size();
// TLSTODO: check it's needed (loading ciphers and certs in
// addition to the library!)
QSslSocketPrivate::ensureInitialized();
DH *dh = q_d2i_DHparams(nullptr, &data, len);
if (dh) {
const auto dhRaii = qScopeGuard([dh] {q_DH_free(dh);});
if (isSafeDH(dh))
*derData = der;
else
return DHParams::UnsafeParametersError;
} else {
return DHParams::InvalidInputDataError;
}
#else
Q_UNUSED(der);
Q_UNUSED(derData);
qCWarning(lcTlsBackend, "Diffie-Hellman parameters are not supported, because OpenSSL v3 was built with deprecated API removed");
#endif
return DHParams::NoError;
}
int QTlsBackendOpenSSL::dhParametersFromPem(const QByteArray &pem, QByteArray *data) const
{
#ifndef OPENSSL_NO_DEPRECATED_3_0
Q_ASSERT(data);
if (pem.isEmpty())
return DHParams::InvalidInputDataError;
// TLSTODO: check it was not a cargo-cult programming in case of
// DH ...
QSslSocketPrivate::ensureInitialized();
BIO *bio = q_BIO_new_mem_buf(const_cast<char *>(pem.data()), pem.size());
if (!bio)
return DHParams::InvalidInputDataError;
const auto bioRaii = qScopeGuard([bio]
{
q_BIO_free(bio);
});
DH *dh = nullptr;
q_PEM_read_bio_DHparams(bio, &dh, nullptr, nullptr);
if (dh) {
const auto dhGuard = qScopeGuard([dh]
{
q_DH_free(dh);
});
if (isSafeDH(dh)) {
char *buf = nullptr;
const int len = q_i2d_DHparams(dh, reinterpret_cast<unsigned char **>(&buf));
const auto freeBuf = qScopeGuard([&] { q_OPENSSL_free(buf); });
if (len > 0)
data->assign({buf, len});
else
return DHParams::InvalidInputDataError;
} else {
return DHParams::UnsafeParametersError;
}
} else {
return DHParams::InvalidInputDataError;
}
#else
Q_UNUSED(pem);
Q_UNUSED(data);
qCWarning(lcTlsBackend, "Diffie-Hellman parameters are not supported, because OpenSSL v3 was built with deprecated API removed");
#endif
return DHParams::NoError;
}
QT_END_NAMESPACE