/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */

#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include "bzlib.h"
#include "archivereader.h"
#include "errors.h"
#ifdef _WIN32
#include "updatehelper.h"
#endif

// These are generated at compile time based on the DER file for the channel
// being used
#ifdef VERIFY_MAR_SIGNATURE
#ifdef TEST_UPDATER
#include "../xpcshellCert.h"
#else
#include "onlineupdate/primaryCert.h"
#include "onlineupdate/secondaryCert.h"
#endif
#endif

#if defined(_WIN32)
#define UPDATER_NO_STRING_GLUE_STL
#endif
#include "nsVersionComparator.h"
#undef UPDATER_NO_STRING_GLUE_STL

#if defined(UNIX)
# include <sys/types.h>
#elif defined(WNT)
# include <io.h>
#endif

static int inbuf_size  = 262144;
static int outbuf_size = 262144;
static char *inbuf  = nullptr;
static char *outbuf = nullptr;

/**
 * Performs a verification on the opened MAR file with the passed in
 * certificate name ID and type ID.
 *
 * @param  archive   The MAR file to verify the signature on.
 * @param  certData  The certificate data.
 * @return OK on success, CERT_VERIFY_ERROR on failure.
*/
template<uint32_t SIZE>
int
VerifyLoadedCert(MarFile *archive, const uint8_t (&certData)[SIZE])
{
    (void)archive;
    (void)certData;

#ifdef VERIFY_MAR_SIGNATURE
    const uint32_t size = SIZE;
    const uint8_t* const data = &certData[0];
    if (mar_verify_signatures(archive, &data, &size, 1))
    {
        return CERT_VERIFY_ERROR;
    }
#endif

    return OK;
}

/**
 * Performs a verification on the opened MAR file.  Both the primary and backup
 * keys stored are stored in the current process and at least the primary key
 * will be tried.  Success will be returned as long as one of the two
 * signatures verify.
 *
 * @return OK on success
*/
int
ArchiveReader::VerifySignature()
{
    if (!mArchive)
    {
        return ARCHIVE_NOT_OPEN;
    }

#ifndef VERIFY_MAR_SIGNATURE
    return OK;
#else
#ifdef TEST_UPDATER
    int rv = VerifyLoadedCert(mArchive, xpcshellCertData);
#else
    int rv = VerifyLoadedCert(mArchive, primaryCertData);
    if (rv != OK)
    {
        rv = VerifyLoadedCert(mArchive, secondaryCertData);
    }
#endif
    return rv;
#endif
}

/**
 * Verifies that the MAR file matches the current product, channel, and version
 *
 * @param MARChannelID   The MAR channel name to use, only updates from MARs
 *                       with a matching MAR channel name will succeed.
 *                       If an empty string is passed, no check will be done
 *                       for the channel name in the product information block.
 *                       If a comma separated list of values is passed then
 *                       one value must match.
 * @param appVersion     The application version to use, only MARs with an
 *                       application version >= to appVersion will be applied.
 * @return OK on success
 *         COULD_NOT_READ_PRODUCT_INFO_BLOCK if the product info block
 *                                           could not be read.
 *         MARCHANNEL_MISMATCH_ERROR         if update-settings.ini's MAR
 *                                           channel ID doesn't match the MAR
 *                                           file's MAR channel ID.
 *         VERSION_DOWNGRADE_ERROR           if the application version for
 *                                           this updater is newer than the
 *                                           one in the MAR.
 */
int
ArchiveReader::VerifyProductInformation(const char *MARChannelID,
                                        const char *appVersion)
{
    if (!mArchive)
    {
        return ARCHIVE_NOT_OPEN;
    }

    ProductInformationBlock productInfoBlock;
    int rv = mar_read_product_info_block(mArchive,
                                         &productInfoBlock);
    if (rv != OK)
    {
        return COULD_NOT_READ_PRODUCT_INFO_BLOCK_ERROR;
    }

    // Only check the MAR channel name if specified, it should be passed in from
    // the update-settings.ini file.
    if (MARChannelID && strlen(MARChannelID))
    {
        // Check for at least one match in the comma separated list of values.
        const char *delimiter = " ,\t";
        // Make a copy of the string in case a read only memory buffer
        // was specified.  strtok modifies the input buffer.
        char channelCopy[512] = { 0 };
        strncpy(channelCopy, MARChannelID, sizeof(channelCopy) - 1);
        char *channel = strtok(channelCopy, delimiter);
        rv = MAR_CHANNEL_MISMATCH_ERROR;
        while (channel)
        {
            if (!strcmp(channel, productInfoBlock.MARChannelID))
            {
                rv = OK;
                break;
            }
            channel = strtok(nullptr, delimiter);
        }
    }

    if (rv == OK)
    {
        /* Compare both versions to ensure we don't have a downgrade
            -1 if appVersion is older than productInfoBlock.productVersion
            1 if appVersion is newer than productInfoBlock.productVersion
            0 if appVersion is the same as productInfoBlock.productVersion
           This even works with strings like:
            - 12.0a1 being older than 12.0a2
            - 12.0a2 being older than 12.0b1
            - 12.0a1 being older than 12.0
            - 12.0 being older than 12.1a1 */
        int versionCompareResult =
            mozilla::CompareVersions(appVersion, productInfoBlock.productVersion);
        if (1 == versionCompareResult)
        {
            rv = VERSION_DOWNGRADE_ERROR;
        }
    }

    free((void *)productInfoBlock.MARChannelID);
    free((void *)productInfoBlock.productVersion);
    return rv;
}

int
ArchiveReader::Open(const NS_tchar *path)
{
    if (mArchive)
        Close();

    if (!inbuf)
    {
        inbuf = (char *)malloc(inbuf_size);
        if (!inbuf)
        {
            // Try again with a smaller buffer.
            inbuf_size = 1024;
            inbuf = (char *)malloc(inbuf_size);
            if (!inbuf)
                return ARCHIVE_READER_MEM_ERROR;
        }
    }

    if (!outbuf)
    {
        outbuf = (char *)malloc(outbuf_size);
        if (!outbuf)
        {
            // Try again with a smaller buffer.
            outbuf_size = 1024;
            outbuf = (char *)malloc(outbuf_size);
            if (!outbuf)
                return ARCHIVE_READER_MEM_ERROR;
        }
    }

#ifdef _WIN32
    mArchive = mar_wopen(path);
#else
    mArchive = mar_open(path);
#endif
    if (!mArchive)
        return READ_ERROR;

    return OK;
}

void
ArchiveReader::Close()
{
    if (mArchive)
    {
        mar_close(mArchive);
        mArchive = nullptr;
    }

    if (inbuf)
    {
        free(inbuf);
        inbuf = nullptr;
    }

    if (outbuf)
    {
        free(outbuf);
        outbuf = nullptr;
    }
}

int
ArchiveReader::ExtractFile(const char *name, const NS_tchar *dest)
{
    const MarItem *item = mar_find_item(mArchive, name);
    if (!item)
        return READ_ERROR;

#ifdef _WIN32
    FILE* fp = _wfopen(dest, L"wb+");
#else
    int fd = creat(dest, item->flags);
    if (fd == -1)
        return WRITE_ERROR;

    FILE *fp = fdopen(fd, "wb");
#endif
    if (!fp)
        return WRITE_ERROR;

    int rv = ExtractItemToStream(item, fp);

    fclose(fp);
    return rv;
}

int
ArchiveReader::ExtractFileToStream(const char *name, FILE *fp)
{
    const MarItem *item = mar_find_item(mArchive, name);
    if (!item)
        return READ_ERROR;

    return ExtractItemToStream(item, fp);
}

int
ArchiveReader::ExtractItemToStream(const MarItem *item, FILE *fp)
{
    /* decompress the data chunk by chunk */

    bz_stream strm;
    int offset, inlen, ret = OK;

    memset(&strm, 0, sizeof(strm));
    if (BZ2_bzDecompressInit(&strm, 0, 0) != BZ_OK)
        return UNEXPECTED_BZIP_ERROR;

    offset = 0;
    for (;;)
    {
        if (!item->length)
        {
            ret = UNEXPECTED_MAR_ERROR;
            break;
        }

        if (offset < (int) item->length && strm.avail_in == 0)
        {
            inlen = mar_read(mArchive, item, offset, inbuf, inbuf_size);
            if (inlen <= 0)
                return READ_ERROR;
            offset += inlen;
            strm.next_in = inbuf;
            strm.avail_in = inlen;
        }

        strm.next_out = outbuf;
        strm.avail_out = outbuf_size;

        ret = BZ2_bzDecompress(&strm);
        if (ret != BZ_OK && ret != BZ_STREAM_END)
        {
            ret = UNEXPECTED_BZIP_ERROR;
            break;
        }

        int outlen = outbuf_size - strm.avail_out;
        if (outlen)
        {
            if (fwrite(outbuf, outlen, 1, fp) != 1)
            {
                ret = WRITE_ERROR_EXTRACT;
                break;
            }
        }

        if (ret == BZ_STREAM_END)
        {
            ret = OK;
            break;
        }
    }

    BZ2_bzDecompressEnd(&strm);
    return ret;
}
