Get back my books from Kindle

fetch_kindle.js

/* 
 * @fileoverview Program to free the content in kindle books as plain HTML.
 *     
 * This is largely based on reverse engineering kindle cloud app
 * (https://read.amazon.com) to read book data from webSQL.
 * 
 * Access to kindle library is required to download this book.
 */

// The Kindle Compression Module copied from http://read.amazon.com application
// The script reuses the same logic to decompress the fragments
var KindleCompression = function() {
    function h(a, c, g) {
        var f, g = g > 0 ? g : b;
        for (f in c)
            c[f] >= g && (g = c[f] + 1);
        f = g;
        for (var d in a)
            for (var g = a[d], e = 2; e <= g.length; e++) {
                var h = g.substr(0, e);
                c.hasOwnProperty(h) || (c[h] = f++)
            }
        return c
    }
    function j(c, e) {
        var l, h = b;
        l = "";
        for (var r = 0; r < e.length; ) {
            var o = e.charAt(r);
            r++;
            o.charCodeAt(0) <= d ? c.hasOwnProperty(l + o) ? l += o : (l.length > 0 && h < f && (c[l + o] = h,
            h++,
            h === a && (h = g)),
            l = o) : l = ""
        }
        return c
    }
    // This is called when lzExpandWithStaticDictionary doesn't have a dictionary passed in
    // in our case, we always construct the dictionary before decompress
    // function e() {
    //     if (defaultDictionary === void 0 || defaultDictionary === {})
    //         defaultDictionary = j({}, defaultDictionaryString);
    //     return defaultDictionary
    // }
    var d = 9983
      , c = d + 1
      , b = c + 100 + 1
      , f = 65533
      , a = 55295
      , g = 57344;
    return {
        lzCompress: function(k) {
            var e = {}, l = [], h, r = b, o, q, s;
            o = h = "";
            for (var t = 0; t < k.length; ) {
                var u = k.charAt(t);
                t++;
                if (u.charCodeAt(0) <= d) {
                    for (; o.length > 0; ) {
                        q = Math.min(100, o.length);
                        s = o.substr(0, q);
                        o = o.substr(q);
                        l.push(c + q);
                        for (q = 0; q < s.length; q++)
                            l.push(s.charCodeAt(q))
                    }
                    e.hasOwnProperty(h + u) ? h += u : (h.length > 0 && (l.push(h.length === 1 ? h.charCodeAt(0) : e[h]),
                    r < f && (e[h + u] = r,
                    r++,
                    r === a && (r = g))),
                    h = u)
                } else
                    h.length > 0 && (l.push(h.length === 1 ? 
                    h.charCodeAt(0) : e[h]),
                    h = ""),
                    o += u
            }
            for (h.length > 0 && l.push(h.length === 1 ? h.charCodeAt(0) : e[h]); o.length > 0; ) {
                q = Math.min(100, o.length);
                s = o.substr(0, q);
                o = o.substr(q);
                l.push(c + q);
                for (q = 0; q < s.length; q++)
                    l.push(s.charCodeAt(q))
            }
            for (i = 0; i < l.length; i++)
                l[i] = String.fromCharCode(l[i]);
            return l.join("")
        },
        lzExpand: function(k) {
            for (var e = {}, l = [], h, r = b, o = "", q, s = 0; s < k.length; ) {
                h = k.charCodeAt(s);
                s++;
                if (h <= d)
                    h = String.fromCharCode(h);
                else if (h >= b)
                    (h = e[h]) || (h = o + q);
                else {
                    o = h - c;
                    l.push(k.substr(s, o));
                    s += o;
                    o = "";
                    continue
                }
                l.push(h);
                q = h.charAt(0);
                r < f && o.length > 0 && (e[r] = o + q,
                r++,
                r === a && (r = g));
                o = h
            }
            return l.join("")
        },
        lzBuildDictionary: j,
        lzGetDecompressionDictionary: function(a) {
            var b = [], c;
            for (c in a)
                b[a[c]] = c;
            return b
        },
        lzAddStringsToDictionary: h,
        lzAddNumbersToDictionary: function(a, b) {
            for (var c = [], g = 100; g < 1E3; g++)
                c.push("" + g);
            return h(c, a, b)
        },
        lzCompressWithStaticDictionary: function(a, b) {
            if (b === void 0 || b === {})
                b = e();
            var g = [], f, h, o, q;
            h = f = "";
            for (var s = 0; s < a.length; ) {
                var t = a.charAt(s);
                s++;
                if (t.charCodeAt(0) <= d) {
                    for (; h.length > 0; ) {
                        o = Math.min(100, 
                        h.length);
                        q = h.substr(0, o);
                        h = h.substr(o);
                        g.push(c + o);
                        for (o = 0; o < q.length; o++)
                            g.push(q.charCodeAt(o))
                    }
                    b.hasOwnProperty(f + t) ? f += t : (f.length > 0 && g.push(f.length === 1 ? f.charCodeAt(0) : b[f]),
                    f = t)
                } else
                    f.length > 0 && (g.push(f.length === 1 ? f.charCodeAt(0) : b[f]),
                    f = ""),
                    h += t
            }
            for (f.length > 0 && g.push(f.length === 1 ? f.charCodeAt(0) : b[f]); h.length > 0; ) {
                o = Math.min(100, h.length);
                q = h.substr(0, o);
                h = h.substr(o);
                g.push(c + o);
                for (o = 0; o < q.length; o++)
                    g.push(q.charCodeAt(o))
            }
            for (i = 0; i < g.length; i++)
                g[i] = String.fromCharCode(g[i]);
            return g.join("")
        },
        lzExpandWithStaticDictionary: function(a, g, f) {
            // NOTE: g is always defined in our case
            // if (g === void 0 || g === []) {
            //     if (defaultDeDictionary === void 0 || defaultDeDictionary === []) {
            //         e();
            //         defaultDeDictionary = [];
            //         for (var h in defaultDictionary)
            //             defaultDeDictionary[defaultDictionary[h]] = h
            //     }
            //     g = defaultDeDictionary
            // }
            h = d;
            var r = b;
            f !== void 0 && (h = f - 1,
            r = f);
            for (var f = [], o = 0; o < a.length; ) {
                var q = a.charCodeAt(o);
                o++;
                q <= h ? f.push(String.fromCharCode(q)) : q >= r ? f.push(g[q]) : (q -= c,
                f.push(a.substr(o, q)),
                o += q)
            }
            return f.join("")
        }
    }
}()

function s(metadata) { // a is bookinfo.metadata
    var b = {};

    if (metadata.cpr !== void 0) {
        KindleCompression.lzAddStringsToDictionary(metadata.cpr, b),
        KindleCompression.lzAddNumbersToDictionary(b);
        return KindleCompression.lzGetDecompressionDictionary(b);
    }

    if (metadata.cprJson !== void 0) {
        KindleCompression.lzAddStringsToDictionary(metadata.cprJson, b, 256),
        KindleCompression.lzAddNumbersToDictionary(b, 256);
        return KindleCompression.lzGetDecompressionDictionary(b);
    }
}

var fs = require('fs');
var path = require('path');
var sqlite3 = require('sqlite3').verbose();
// 

// http://read.amazon.com stores the ebook with webSQL, which is a sqlite accessible in Chrome
// To locate the sqlite file: http://ahoj.io/how-to-delete-web-sql-database-in-google-chrome
var KINDLE_DB = os.homedir() + '/Library/Application\ Support/Google/Chrome/Default/databases/https_read.amazon.com_0/17';
var db = new sqlite3.Database(KINDLE_DB);

// The following hack is from reverse engineering how kindle cloud app reads data
db.all("select metadata from 'bookinfo'", function(err, rows) {
    rows.forEach(function (row) {
        var metadata = JSON.parse(row.metadata);
        var title = metadata.title;
        var authors = metadata.authorList.join(',');
        // used for dictionary request at https://read.amazon.com/dict/getDefinition?asin=<asin>&word=<word>
        var asin = metadata.asin;
        var ca = s(metadata);

        console.log('staring process book: ' + title);

        var HtmlHeader = '<html><head>' +
            '<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">' +
            '<meta name="author" content="' + authors + '">' +
            '</head><body id="' + asin + '">';
        var HtmlFile = path.join(os.tmpdir(), title.replace(/\s+/g, '-') + '.html');

        fs.writeFile(HtmlFile, HtmlHeader);
        console.log("created the file with HTML headers.");

        db.all("select id, piece, other from 'fragments' order by id", function(err, rows) {
            rows.forEach(function (row) {
                var id = row.id;
                var compressedFragmentData = row.piece;
                var uncompressedFragmentData;
                var imageDataMap = JSON.parse(row.other).imageData || {};
                uncompressedFragmentData = KindleCompression.lzExpandWithStaticDictionary(
                    row.piece, ca);
                // replace image path with base64 encoded string
                for (var image in imageDataMap) {
                    uncompressedFragmentData = uncompressedFragmentData.replace(
                        'dataUrl="' + image + '"',
                        'src="' + imageDataMap[image] + '"');
                }
                fs.appendFile(HtmlFile, uncompressedFragmentData);
            });
        });

        fs.appendFile(HtmlFile, '</body></html>');
        console.log("created the file at: " + HtmlFile);
    });
});

I have made the changes suggested by ICWiz above along with a couple of package version updates and have issued a pull request to the https://github.com/d10r/kindle-fetch repository.

Hi guys,

For all those wondering if the script still works, it does :) ! Just been using it to convert a book tonight.
Have a look at the different version for node, chrome and macOS I have on this issue : d10r/kindle-fetch#9.
Thx to all the people that did that amazing work ! Been struggling for several week with a reliable and free way to crack DRM (hate DRM) !!!

Cheers !

I tried to convert a file. The output file is 0KB. please help me.

It doesn't seem to work no more !
I used this script https://github.com/d10r/kindle-fetch from @d10r and end up with the following error :

/home/iongradea/DEV/project_kindle_2_epub/kindle-fetch/node_modules/sqlite3/lib/trace.js:27
                    throw err;
                    ^
no metadata found, probably not a valid file

After downloading sqlite3 to look at the data base there is no bookinfo (line 274) and the content is pretty empty. It seems the browser doesn't download automatically and I can't manage to right click and ask to download. Seems it has been removed on Amazon Cloud Reader,

Here the print witht sqlit3, I checked all the tables :

sqlite> .tables
__WebKitDatabaseInfoTable__  keyValue                   
bookdata                     metrics                    
journal   

I would be more than happy to be wrong and it still works !
If someone has any clue !

Cheers,
Ion

Fiy more details :

• node version : v8.10.0
• Linux version : ubuntu 18.04 LTS
• chrome://version

Google Chrome | 88.0.4324.150 (Official Build) (64-bit)
-- | --
Revision | e6c2a846b660e61f059daee2c46217af42913240-refs/branch-heads/4324@{#2103}
OS | Linux
JavaScript | V8 8.8.278.15
User Agent | Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36
Command Line | /usr/bin/google-chrome-stable --flag-switches-begin --flag-switches-end --origin-trial-disabled-features=SecurePaymentConfirmation
Executable Path | /opt/google/chrome/google-chrome
Profile Path | /home/iongradea/.config/google-chrome/Default