/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <com/sun/star/lang/IllegalArgumentException.hpp>
#include <com/sun/star/mozilla/XMozillaBootstrap.hpp>
#include <com/sun/star/xml/crypto/DigestID.hpp>
#include <com/sun/star/xml/crypto/CipherID.hpp>
#include <com/sun/star/uno/XComponentContext.hpp>
#include <cppuhelper/supportsservice.hxx>
#include <officecfg/Office/Common.hxx>
#include <sal/types.h>
#include <rtl/bootstrap.hxx>
#include <rtl/string.hxx>
#include <osl/file.hxx>
#include <osl/thread.h>
#include <sal/log.hxx>
#include <tools/diagnose_ex.h>
#include <unotools/tempfile.hxx>
#include <salhelper/singletonref.hxx>

#include <nss/nssinitializer.hxx>

#include "digestcontext.hxx"
#include "ciphercontext.hxx"

#include <memory>
#include <vector>

#include <nss.h>
#include <pk11pub.h>
#include <secmod.h>
#include <prerror.h>
#include <prinit.h>

namespace cssu = css::uno;
namespace cssl = css::lang;

using namespace com::sun::star;

#define ROOT_CERTS "Root Certs for OpenOffice.org"

extern "C" {

static void nsscrypto_finalize();

}

namespace
{

class InitNSSPrivate
{
private:
    std::unique_ptr<utl::TempFile> m_pTempFileDatabaseDirectory;

public:
    OUString getTempDatabasePath()
    {
        if (!m_pTempFileDatabaseDirectory)
        {
            m_pTempFileDatabaseDirectory.reset(new utl::TempFile(nullptr, true));
            m_pTempFileDatabaseDirectory->EnableKillingFile();
        }
        return m_pTempFileDatabaseDirectory->GetFileName();
    }

    void reset()
    {
        if (m_pTempFileDatabaseDirectory)
        {
            m_pTempFileDatabaseDirectory.reset();
        }
    }
};

salhelper::SingletonRef<InitNSSPrivate>* getInitNSSPrivate()
{
    static salhelper::SingletonRef<InitNSSPrivate> aInitNSSPrivate;
    return &aInitNSSPrivate;
}

bool nsscrypto_initialize( const css::uno::Reference< css::uno::XComponentContext > &rxContext, bool & out_nss_init );

#ifdef XMLSEC_CRYPTO_NSS

void deleteRootsModule()
{
    SECMODModule *RootsModule = nullptr;
    SECMODModuleList *list = SECMOD_GetDefaultModuleList();
    SECMODListLock *lock = SECMOD_GetDefaultModuleListLock();
    SECMOD_GetReadLock(lock);

    while (!RootsModule && list)
    {
        SECMODModule *module = list->module;

        for (int i=0; i < module->slotCount; i++)
        {
            PK11SlotInfo *slot = module->slots[i];
            if (PK11_IsPresent(slot))
            {
                if (PK11_HasRootCerts(slot))
                {
                    SAL_INFO("xmlsecurity.xmlsec", "The root certificates module \"" << module->commonName << "\" is already loaded: " << module->dllName);

                    RootsModule = SECMOD_ReferenceModule(module);
                    break;
                }
            }
        }
        list = list->next;
    }
    SECMOD_ReleaseReadLock(lock);

    if (RootsModule)
    {
        PRInt32 modType;
        if (SECSuccess == SECMOD_DeleteModule(RootsModule->commonName, &modType))
        {
            SAL_INFO("xmlsecurity.xmlsec", "Deleted module \"" << RootsModule->commonName << "\".");
        }
        else
        {
            SAL_INFO("xmlsecurity.xmlsec", "Failed to delete \"" << RootsModule->commonName << "\": " << RootsModule->dllName);
        }
        SECMOD_DestroyModule(RootsModule);
        RootsModule = nullptr;
    }
}

OString getMozillaCurrentProfile( const css::uno::Reference< css::uno::XComponentContext > &rxContext )
{
    // first, try to get the profile from "MOZILLA_CERTIFICATE_FOLDER"
    const char* pEnv = getenv("MOZILLA_CERTIFICATE_FOLDER");
    if (pEnv)
    {
        SAL_INFO(
            "xmlsecurity.xmlsec",
            "Using Mozilla profile from MOZILLA_CERTIFICATE_FOLDER=" << pEnv);
        return pEnv;
    }

    // second, try to get saved user-preference
    try
    {
        OUString sUserSetCertPath =
            officecfg::Office::Common::Security::Scripting::CertDir::get().value_or(OUString());

        if (!sUserSetCertPath.isEmpty())
        {
            SAL_INFO(
                "xmlsecurity.xmlsec",
                "Using Mozilla profile from /org.openoffice.Office.Common/"
                    "Security/Scripting/CertDir: " << sUserSetCertPath);
            return OUStringToOString(sUserSetCertPath, osl_getThreadTextEncoding());
        }
    }
    catch (const uno::Exception &)
    {
        TOOLS_WARN_EXCEPTION("xmlsecurity.xmlsec", "getMozillaCurrentProfile:");
    }

    // third, dig around to see if there's one available
    mozilla::MozillaProductType productTypes[3] = {
        mozilla::MozillaProductType_Thunderbird,
        mozilla::MozillaProductType_Firefox,
        mozilla::MozillaProductType_Mozilla };

    uno::Reference<uno::XInterface> xInstance = rxContext->getServiceManager()->createInstanceWithContext("com.sun.star.mozilla.MozillaBootstrap", rxContext);
    OSL_ENSURE( xInstance.is(), "failed to create instance" );

    uno::Reference<mozilla::XMozillaBootstrap> xMozillaBootstrap(xInstance,uno::UNO_QUERY);
    OSL_ENSURE( xMozillaBootstrap.is(), "failed to create instance" );

    if (xMozillaBootstrap.is())
    {
        for (int i=0; i<int(SAL_N_ELEMENTS(productTypes)); ++i)
        {
            OUString profile = xMozillaBootstrap->getDefaultProfile(productTypes[i]);

            if (!profile.isEmpty())
            {
                OUString sProfilePath = xMozillaBootstrap->getProfilePath( productTypes[i], profile );
                SAL_INFO(
                    "xmlsecurity.xmlsec",
                    "Using Mozilla profile " << sProfilePath);
                return OUStringToOString(sProfilePath, osl_getThreadTextEncoding());
            }
        }
    }

    SAL_INFO("xmlsecurity.xmlsec", "No Mozilla profile found");
    return OString();
}

#endif

//Older versions of Firefox (FF), for example FF2, and Thunderbird (TB) 2 write
//the roots certificate module (libnssckbi.so), which they use, into the
//profile. This module will then already be loaded during NSS_Init (and the
//other init functions). This fails in two cases. First, FF3 was used to create
//the profile, or possibly used that profile before, and second the profile was
//used on a different platform.
//
//Then one needs to add the roots module oneself. This should be done with
//SECMOD_LoadUserModule rather than SECMOD_AddNewModule. The latter would write
//the location of the roots module to the profile, which makes FF2 and TB2 use
//it instead of their own module.
//
//When using SYSTEM_NSS then the libnss3.so lib is typically found in /usr/lib.
//This folder may, however, NOT contain the roots certificate module. That is,
//just providing the library name in SECMOD_LoadUserModule or
//SECMOD_AddNewModule will FAIL to load the mozilla unless the LD_LIBRARY_PATH
//contains an FF or TB installation.
//ATTENTION: DO NOT call this function directly instead use initNSS
//return true - whole initialization was successful
//param out_nss_init = true: at least the NSS initialization (NSS_InitReadWrite
//was successful and therefore NSS_Shutdown should be called when terminating.
bool nsscrypto_initialize(css::uno::Reference<css::uno::XComponentContext> const & rxContext, bool & out_nss_init)
{
    // this method must be called only once, no need for additional lock
    OString sCertDir;

#ifdef XMLSEC_CRYPTO_NSS
    sCertDir = getMozillaCurrentProfile(rxContext);
#else
    (void) rxContext;
#endif
    SAL_INFO("xmlsecurity.xmlsec",  "Using profile: " << sCertDir );

    PR_Init( PR_USER_THREAD, PR_PRIORITY_NORMAL, 1 ) ;

    bool bSuccess = false;
    // there might be no profile
    if (!sCertDir.isEmpty())
    {
        if (sCertDir.indexOf(':') == -1) //might be env var with explicit prefix
        {
            OUString sCertDirURL;
            osl::FileBase::getFileURLFromSystemPath(
                OStringToOUString(sCertDir, osl_getThreadTextEncoding()),
                sCertDirURL);
            osl::DirectoryItem item;
            if (osl::FileBase::E_NOENT != osl::DirectoryItem::get(sCertDirURL + "/cert8.db", item) &&
                osl::FileBase::E_NOENT == osl::DirectoryItem::get(sCertDirURL + "/cert9.db", item))
            {
                SAL_INFO("xmlsecurity.xmlsec", "nsscrypto_initialize: trying to avoid profile migration");
                sCertDir = "dbm:" + sCertDir;
            }
        }
        if (NSS_InitReadWrite(sCertDir.getStr()) != SECSuccess)
        {
            SAL_INFO("xmlsecurity.xmlsec", "Initializing NSS with profile failed.");
            int errlen = PR_GetErrorTextLength();
            if (errlen > 0)
            {
                std::unique_ptr<char[]> const error(new char[errlen + 1]);
                PR_GetErrorText(error.get());
                SAL_INFO("xmlsecurity.xmlsec", error.get());
            }
        }
        else
        {
            bSuccess = true;
        }
    }

    if (!bSuccess) // Try to create a database in temp dir
    {
        SAL_INFO("xmlsecurity.xmlsec", "Initializing NSS with a temporary profile.");
        OUString rString = (*getInitNSSPrivate())->getTempDatabasePath();

        if (NSS_InitReadWrite(rString.toUtf8().getStr()) != SECSuccess)
        {
            SAL_INFO("xmlsecurity.xmlsec", "Initializing NSS with a temporary profile.");
            int errlen = PR_GetErrorTextLength();
            if(errlen > 0)
            {
                std::unique_ptr<char[]> const error(new char[errlen + 1]);
                PR_GetErrorText(error.get());
                SAL_INFO("xmlsecurity.xmlsec", error.get());
            }
            return false;
        }
        // Initialize and set empty password if needed
        PK11SlotInfo* pSlot = PK11_GetInternalKeySlot();
        if (pSlot)
        {
            if (PK11_NeedUserInit(pSlot))
                PK11_InitPin(pSlot, nullptr, nullptr);
            PK11_FreeSlot(pSlot);
        }
    }
    out_nss_init = true;

#ifdef XMLSEC_CRYPTO_NSS
    bool return_value = true;

#if defined SYSTEM_NSS
    if (!SECMOD_HasRootCerts())
#endif
    {
        deleteRootsModule();

#if defined SYSTEM_NSS
        OUString rootModule("libnssckbi" SAL_DLLEXTENSION);
#else
        OUString rootModule("${LO_LIB_DIR}/libnssckbi" SAL_DLLEXTENSION);
#endif
        ::rtl::Bootstrap::expandMacros(rootModule);

        OUString rootModulePath;
        if (::osl::File::E_None == ::osl::File::getSystemPathFromFileURL(rootModule, rootModulePath))
        {
            OString ospath = OUStringToOString(rootModulePath, osl_getThreadTextEncoding());
            OString aStr = "name=\"" ROOT_CERTS "\" library=\"" + ospath + "\"";

            SECMODModule * RootsModule =
                SECMOD_LoadUserModule(
                    const_cast<char*>(aStr.getStr()),
                    nullptr, // no parent
                    PR_FALSE); // do not recurse

            if (RootsModule)
            {

                bool found = RootsModule->loaded;

                SECMOD_DestroyModule(RootsModule);
                RootsModule = nullptr;
                if (found)
                    SAL_INFO("xmlsecurity.xmlsec", "Added new root certificate module " ROOT_CERTS " contained in " << ospath);
                else
                {
                    SAL_INFO("xmlsecurity.xmlsec", "FAILED to load the new root certificate module " ROOT_CERTS "contained in " << ospath);
                    return_value = false;
                }
            }
            else
            {
                SAL_INFO("xmlsecurity.xmlsec", "FAILED to add new root certificate module " ROOT_CERTS  " contained in " << ospath);
                return_value = false;

            }
        }
        else
        {
            SAL_INFO("xmlsecurity.xmlsec", "Adding new root certificate module failed.");
            return_value = false;
        }
    }

    return return_value;
#else
    return true;
#endif
}

} // namespace

// must be extern "C" because we pass the function pointer to atexit
extern "C" void nsscrypto_finalize()
{
    SECMODModule *RootsModule = SECMOD_FindModule(ROOT_CERTS);

    if (RootsModule)
    {

        if (SECSuccess == SECMOD_UnloadUserModule(RootsModule))
        {
            SAL_INFO("xmlsecurity.xmlsec", "Unloaded module \"" ROOT_CERTS "\".");
        }
        else
        {
            SAL_INFO("xmlsecurity.xmlsec", "Failed unloading module \"" ROOT_CERTS "\".");
        }
        SECMOD_DestroyModule(RootsModule);
    }
    else
    {
        SAL_INFO("xmlsecurity.xmlsec", "Unloading module \"" ROOT_CERTS "\" failed because it was not found.");
    }
    PK11_LogoutAll();
    (void)NSS_Shutdown();

    (*getInitNSSPrivate())->reset();
}

ONSSInitializer::ONSSInitializer(
    const css::uno::Reference< css::uno::XComponentContext > &rxContext)
    :m_xContext( rxContext )
{
}

ONSSInitializer::~ONSSInitializer()
{
}

bool ONSSInitializer::initNSS( const css::uno::Reference< css::uno::XComponentContext > &rxContext )
{
    static bool gbInitialized = [&rxContext]()
        {
            bool bNSSInit = false;
            bool bInitialized = nsscrypto_initialize( rxContext, bNSSInit );
            if (bNSSInit)
                atexit(nsscrypto_finalize);
            return bInitialized;
        }();
    return gbInitialized;
}

css::uno::Reference< css::xml::crypto::XDigestContext > SAL_CALL ONSSInitializer::getDigestContext( ::sal_Int32 nDigestID, const css::uno::Sequence< css::beans::NamedValue >& aParams )
{
    SECOidTag nNSSDigestID = SEC_OID_UNKNOWN;
    sal_Int32 nDigestLength = 0;
    bool b1KData = false;
    if ( nDigestID == css::xml::crypto::DigestID::SHA256
      || nDigestID == css::xml::crypto::DigestID::SHA256_1K )
    {
        nNSSDigestID = SEC_OID_SHA256;
        nDigestLength = 32;
        b1KData = ( nDigestID == css::xml::crypto::DigestID::SHA256_1K );
    }
    else if ( nDigestID == css::xml::crypto::DigestID::SHA1
           || nDigestID == css::xml::crypto::DigestID::SHA1_1K )
    {
        nNSSDigestID = SEC_OID_SHA1;
        nDigestLength = 20;
        b1KData = ( nDigestID == css::xml::crypto::DigestID::SHA1_1K );
    }
    else if ( nDigestID == css::xml::crypto::DigestID::SHA512
           || nDigestID == css::xml::crypto::DigestID::SHA512_1K )
    {
        nNSSDigestID = SEC_OID_SHA512;
        nDigestLength = 64;
        b1KData = ( nDigestID == css::xml::crypto::DigestID::SHA512_1K );
    }
    else
        throw css::lang::IllegalArgumentException("Unexpected digest requested.", css::uno::Reference< css::uno::XInterface >(), 1 );

    if ( aParams.hasElements() )
        throw css::lang::IllegalArgumentException("Unexpected arguments provided for digest creation.", css::uno::Reference< css::uno::XInterface >(), 2 );

    css::uno::Reference< css::xml::crypto::XDigestContext > xResult;
    if( initNSS( m_xContext ) )
    {
        PK11Context* pContext = PK11_CreateDigestContext( nNSSDigestID );
        if ( pContext && PK11_DigestBegin( pContext ) == SECSuccess )
            xResult = new ODigestContext( pContext, nDigestLength, b1KData );
    }

    return xResult;
}

css::uno::Reference< css::xml::crypto::XCipherContext > SAL_CALL ONSSInitializer::getCipherContext( ::sal_Int32 nCipherID, const css::uno::Sequence< ::sal_Int8 >& aKey, const css::uno::Sequence< ::sal_Int8 >& aInitializationVector, sal_Bool bEncryption, const css::uno::Sequence< css::beans::NamedValue >& aParams )
{
    CK_MECHANISM_TYPE nNSSCipherID = 0;
    bool bW3CPadding = false;
    if ( nCipherID != css::xml::crypto::CipherID::AES_CBC_W3C_PADDING )
        throw css::lang::IllegalArgumentException("Unexpected cipher requested.", css::uno::Reference< css::uno::XInterface >(), 1 );

    nNSSCipherID = CKM_AES_CBC;
    bW3CPadding = true;

    if ( aKey.getLength() != 16 && aKey.getLength() != 24 && aKey.getLength() != 32 )
        throw css::lang::IllegalArgumentException("Unexpected key length.", css::uno::Reference< css::uno::XInterface >(), 2 );

    if ( aParams.hasElements() )
        throw css::lang::IllegalArgumentException("Unexpected arguments provided for cipher creation.", css::uno::Reference< css::uno::XInterface >(), 5 );

    css::uno::Reference< css::xml::crypto::XCipherContext > xResult;
    if( initNSS( m_xContext ) )
    {
        if ( aInitializationVector.getLength() != PK11_GetIVLength( nNSSCipherID ) )
            throw css::lang::IllegalArgumentException("Unexpected length of initialization vector.", css::uno::Reference< css::uno::XInterface >(), 3 );

        xResult = OCipherContext::Create( nNSSCipherID, aKey, aInitializationVector, bEncryption, bW3CPadding );
    }

    return xResult;
}

/* XServiceInfo */
OUString SAL_CALL ONSSInitializer::getImplementationName()
{
    return "com.sun.star.xml.crypto.NSSInitializer";
}

sal_Bool SAL_CALL ONSSInitializer::supportsService( const OUString& rServiceName )
{
    return cppu::supportsService(this, rServiceName);
}

cssu::Sequence< OUString > SAL_CALL ONSSInitializer::getSupportedServiceNames(  )
{
    return { NSS_SERVICE_NAME };
}

#ifndef XMLSEC_CRYPTO_NSS
extern "C" SAL_DLLPUBLIC_EXPORT uno::XInterface*
com_sun_star_xml_crypto_NSSInitializer_get_implementation(
    uno::XComponentContext* pCtx, uno::Sequence<uno::Any> const& /*rSeq*/)
{
    return cppu::acquire(new ONSSInitializer(pCtx));
}
#endif

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