BruteForce.cs for BIP-38

/* Inspired by:
 * https://www.reddit.com/r/btc/comments/4dkw1q/no_one_cracked_05btc_paperwallet_with_easy/ ( https://archive.is/1y58e )
 *
 * A very inefficient way to generate every possible password meeting the following criteria:
 *
 * 1: Password is 6 characters long
 * 2: Password is made up of ONLY letters from the US alphabet, lower and upper case (a-z and A-Z). No symbols or numbers.
 * 3: If you divide the number of uppercase letters by the number of lower case letters in the password, you get an integer
 *    (assume this means there are 3, 4, or 5 upper-case letters in the password).
 *
 * Then write every 100,000 passwords out to a new file, which can be used to attempt to actually bruteforce the passwords in the file(s) using something like
 * https://github.com/Dirbaio/bip38-cracker ( https://archive.is/OrHRc )
 * Note that BIP-38 intentionally makes it time consuming to attempt passwords, so trying all ~20 billion (52^6) in one go is unrealistic.
 * Hence breaking them up into subsets of 100,000 passwords.
 */

using UnityEngine;
using System.Collections;
using System;
using System.Text;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

// Attach this component to an object in Unity and let it do its thing.
public class BruteForce : MonoBehavior {
    public int startPos1 = 0;
    public int startPos2 = 0;
    public int startPos3 = 0;
    public int startPos4 = 0;
    public int startPos5 = 0;
    public int startPos6 = 0;

    public int startFile = 0;

    string chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

    string outputFile = "bf.txt";

    void Start() {
        if (!File.Exists(outputFile)) {
            File.Create(outputFile);
        }

        StartCoroutine(GenerateFile());
    }

    IEnumerator GenerateFile() {
        yield return new WaitForSeconds(0.25f);

        StringBuilder result = new StringBuilder();
        int linesAdded = 0;
        int filesWritten = startFile;

        float timer = Time.realtimeSinceStartup;

        #region sanity checking

        if (startPos6 >= 52) {
            startPos6 = 0;
            startPos5++;
        }

        if (startPos5 >= 52) {
            startPos5 = 0;
            startPos4++;
        }

        if (startPos4 >= 52) {
            startPos4 = 0;
            startPos3++;
        }

        if (startPos3 >= 52) {
            startPos3 = 0;
            startPos2++;
        }

        if (startPos2 >= 52) {
            startPos2 = 0;
            startPos1++;
        }

        #endregion //sanity checking

        int chr1 = startPos1;
        int chr2 = startPos2;
        int chr3 = startPos3;
        int chr4 = startPos4;
        int chr5 = startPos5;
        int chr6 = startPos6;

        Debug.Log("Starting at positions: " + chr1 + " " + chr2 + " " + chr3 + " " + chr4 + " " + chr5 + " " + chr6 +
            " Chars length is: " + chars.Length);
        yield return 0;

        for (chr1 = startPos1; chr1 < chars.Length; chr1++) {
            startPos1 = 0;

            for (chr2 = startPos2; chr2 < chars.Length; chr2++) {
                startPos2 = 0;

                for (chr3 = startPos3; chr3 < chars.Length; chr3++) {
                    startPos3 = 0;

                    for (chr4 = startPos4; chr4 < chars.Length; chr4++) {
                        startPos4 = 0;

                        for (chr5 = startPos5; chr5 < chars.Length; chr5++) {
                            startPos5 = 0;

                            for (chr6 = startPos6; chr6 < chars.Length; chr6++) {
                                startPos6 = 0;

                                if (PwdMeetsCriteria(chr1, chr2, chr3, chr4, chr5, chr6)) {
                                    string pwd = chars.Substring(chr1, 1) + chars.Substring(chr2, 1) + chars.Substring(chr3, 1) + chars.Substring(chr4, 1) + chars.Substring(chr5, 1) + chars.Substring(chr6, 1);
                                    result.AppendLine(pwd);
                                    linesAdded++;

                                    if (linesAdded >= 100000) {
                                        File.AppendAllText(String.Format("bf/bf{0:D6}.txt", filesWritten), result.ToString(), new System.Text.UTF8Encoding());
                                        filesWritten++;
                                        Debug.LogWarning("Writing out file #" + filesWritten.ToString("N0") +
                                            ".\nCurrently done with: " + chr1 + " " + chr2 + " " + chr3 + " " + chr4 + " " + chr5 + " " + (chr6 + 1));
                                        // reset these things back to the beginning
                                        linesAdded = 0;
                                        result = new StringBuilder();
                                        //yield return 0;
                                    }
                                } else {
                                    chr6 = (chr6 == 0) ? 25 : 51;
                                }

                                if (Time.realtimeSinceStartup > (timer + 1)) {
                                    //Debug.Log("RealTime Since Startup: " + Time.realtimeSinceStartup);
                                    // reset timer and display progress
                                    timer = Time.realtimeSinceStartup;
                                    Debug.Log("Progress: " + ((UInt64)(((UInt64)chr1 * 52L * 52L * 52L * 52L * 52L) + ((UInt64)chr2 * 52L * 52L * 52L * 52L) + ((UInt64)chr3 * 52L * 52L * 52L) + ((UInt64)chr4 * 52L * 52L) + ((UInt64)chr5 * 52L) + ((UInt64)chr6))).ToString("N0") +
                                        " of 19,763,298,048" +
                                        ".\nLines added: " + linesAdded.ToString("N0") +
                                        ".\nCurrently done with: " + chr1 + " " + chr2 + " " + chr3 + " " + chr4 + " " + chr5 + " " + (chr6 + 1));
                                    yield return 0;
                                }
                            }
                        }
                    }
                }
            }
        }

        if (linesAdded > 0) {
            File.AppendAllText(String.Format("bf/bf{0:D6}.txt", filesWritten), result.ToString(), new System.Text.UTF8Encoding());
            filesWritten++;
        }

        Debug.Log("FINISHED! Currently done with: " + chr1 + " " + chr2 + " " + chr3 + " " + chr4 + " " + chr5 + " " + chr6);
    }

    bool PwdMeetsCriteria(int chr1, int chr2, int chr3, int chr4, int chr5, int chr6) {
        int lower = 0;
        int upper = 0;

        if (chr1 < 26) { lower++; } else { upper++; }
        if (chr2 < 26) { lower++; } else { upper++; }
        if (chr3 < 26) { lower++; } else { upper++; }
        if (chr4 < 26) { lower++; } else { upper++; }
        if (chr5 < 26) { lower++; } else { upper++; }
        if (chr6 < 26) { lower++; } else { upper++; }

        if (upper == 3 || upper == 4 || upper == 5) {
            return true;
        } else {
            return false;
        }
    }
}