当我们网站上的用户丢失密码并前往“忘记密码”页面时,我们需要给他一个新的临时密码。我真的不介意它是多么随机,或者如果它匹配所有“需要的”强密码规则,我想要做的就是给他们一个密码,以便以后更改。
该应用程序是一个用C#编写的Web应用程序。所以我一直在考虑使用Guid的简单方法。即
Guid.NewGuid().ToString("d").Substring(1,8)
建议?想法?
我创建此方法类似于成员资格提供程序中提供的方法。如果您不想在某些应用程序中添加Web引用,这将非常有用。
它很棒。
public static string GeneratePassword(int Length, int NonAlphaNumericChars)
{
string allowedChars = "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ0123456789";
string allowedNonAlphaNum = "!@#$%^&*()_-+=[{]};:<>|./?";
Random rd = new Random();
if (NonAlphaNumericChars > Length || Length <= 0 || NonAlphaNumericChars < 0)
throw new ArgumentOutOfRangeException();
char[] pass = new char[Length];
int[] pos = new int[Length];
int i = 0, j = 0, temp = 0;
bool flag = false;
//Random the position values of the pos array for the string Pass
while (i < Length - 1)
{
j = 0;
flag = false;
temp = rd.Next(0, Length);
for (j = 0; j < Length; j++)
if (temp == pos[j])
{
flag = true;
j = Length;
}
if (!flag)
{
pos[i] = temp;
i++;
}
}
//Random the AlphaNumericChars
for (i = 0; i < Length - NonAlphaNumericChars; i++)
pass[i] = allowedChars[rd.Next(0, allowedChars.Length)];
//Random the NonAlphaNumericChars
for (i = Length - NonAlphaNumericChars; i < Length; i++)
pass[i] = allowedNonAlphaNum[rd.Next(0, allowedNonAlphaNum.Length)];
//Set the sorted array values by the pos array for the rigth posistion
char[] sorted = new char[Length];
for (i = 0; i < Length; i++)
sorted[i] = pass[pos[i]];
string Pass = new String(sorted);
return Pass;
}
我一直对KeePass内置的密码生成器非常满意。由于KeePass是一个.Net程序和开源,我决定挖掘一下代码。我最后只是引用标准应用程序安装中提供的副本KeePass.exe作为我项目中的参考并编写下面的代码。通过KeePass,您可以看到它的灵活性。您可以指定长度,包含/不包括哪些字符等...
using KeePassLib.Cryptography.PasswordGenerator;
using KeePassLib.Security;
public static string GeneratePassword(int passwordLength, bool lowerCase, bool upperCase, bool digits,
bool punctuation, bool brackets, bool specialAscii, bool excludeLookAlike)
{
var ps = new ProtectedString();
var profile = new PwProfile();
profile.CharSet = new PwCharSet();
profile.CharSet.Clear();
if (lowerCase)
profile.CharSet.AddCharSet('l');
if(upperCase)
profile.CharSet.AddCharSet('u');
if(digits)
profile.CharSet.AddCharSet('d');
if (punctuation)
profile.CharSet.AddCharSet('p');
if (brackets)
profile.CharSet.AddCharSet('b');
if (specialAscii)
profile.CharSet.AddCharSet('s');
profile.ExcludeLookAlike = excludeLookAlike;
profile.Length = (uint)passwordLength;
profile.NoRepeatingCharacters = true;
KeePassLib.Cryptography.PasswordGenerator.PwGenerator.Generate(out ps, profile, null, _pool);
return ps.ReadString();
}
我喜欢看生成密码,就像生成软件密钥一样。您应该从一系列遵循良好实践的角色中进行选择。拿@Radu094 answered和修改它遵循良好做法。不要在字符数组中放入每个字母。有些信件通过电话更难说或理解。
您还应该考虑对生成的密码使用校验和,以确保它是由您生成的。实现这一目标的一个好方法是使用LUHN algorithm。
这就是我快速拼凑的内容。
public string GeneratePassword(int len)
{
string res = "";
Random rnd = new Random();
while (res.Length < len) res += (new Func<Random, string>((r) => {
char c = (char)((r.Next(123) * DateTime.Now.Millisecond % 123));
return (Char.IsLetterOrDigit(c)) ? c.ToString() : "";
}))(rnd);
return res;
}
public static string GeneratePassword(int passLength) {
var chars = "abcdefghijklmnopqrstuvwxyz@#$&ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var random = new Random();
var result = new string(
Enumerable.Repeat(chars, passLength)
.Select(s => s[random.Next(s.Length)])
.ToArray());
return result;
}
这很简短,对我来说很有用。
public static string GenerateRandomCode(int length)
{
Random rdm = new Random();
StringBuilder sb = new StringBuilder();
for(int i = 0; i < length; i++)
sb.Append(Convert.ToChar(rdm.Next(101,132)));
return sb.ToString();
}
在我的网站上我使用这种方法:
//Symb array
private const string _SymbolsAll = "~`!@#$%^&*()_+=-\\|[{]}'\";:/?.>,<";
//Random symb
public string GetSymbol(int Length)
{
Random Rand = new Random(DateTime.Now.Millisecond);
StringBuilder result = new StringBuilder();
for (int i = 0; i < Length; i++)
result.Append(_SymbolsAll[Rand.Next(0, _SymbolsAll.Length)]);
return result.ToString();
}
编辑数组列表的字符串_SymbolsAll
。
在接受的答案中添加了一些补充代码。它仅使用Random改进了答案,并允许一些密码选项。我也喜欢KeePass答案中的一些选项,但不想在我的解决方案中包含可执行文件。
private string RandomPassword(int length, bool includeCharacters, bool includeNumbers, bool includeUppercase, bool includeNonAlphaNumericCharacters, bool includeLookAlikes)
{
if (length < 8 || length > 128) throw new ArgumentOutOfRangeException("length");
if (!includeCharacters && !includeNumbers && !includeNonAlphaNumericCharacters) throw new ArgumentException("RandomPassword-Key arguments all false, no values would be returned");
string pw = "";
do
{
pw += System.Web.Security.Membership.GeneratePassword(128, 25);
pw = RemoveCharacters(pw, includeCharacters, includeNumbers, includeUppercase, includeNonAlphaNumericCharacters, includeLookAlikes);
} while (pw.Length < length);
return pw.Substring(0, length);
}
private string RemoveCharacters(string passwordString, bool includeCharacters, bool includeNumbers, bool includeUppercase, bool includeNonAlphaNumericCharacters, bool includeLookAlikes)
{
if (!includeCharacters)
{
var remove = new string[] { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z" };
foreach (string r in remove)
{
passwordString = passwordString.Replace(r, string.Empty);
passwordString = passwordString.Replace(r.ToUpper(), string.Empty);
}
}
if (!includeNumbers)
{
var remove = new string[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" };
foreach (string r in remove)
passwordString = passwordString.Replace(r, string.Empty);
}
if (!includeUppercase)
passwordString = passwordString.ToLower();
if (!includeNonAlphaNumericCharacters)
{
var remove = new string[] { "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "-", "_", "+", "=", "{", "}", "[", "]", "|", "\\", ":", ";", "<", ">", "/", "?", "." };
foreach (string r in remove)
passwordString = passwordString.Replace(r, string.Empty);
}
if (!includeLookAlikes)
{
var remove = new string[] { "(", ")", "0", "O", "o", "1", "i", "I", "l", "|", "!", ":", ";" };
foreach (string r in remove)
passwordString = passwordString.Replace(r, string.Empty);
}
return passwordString;
}
这是我搜索生成随机密码时的第一个链接,以下内容超出了当前问题的范围,但可能需要考虑。
System.Web.Security.Membership.GeneratePassword
在加密方面是安全的假设,其中至少20%的字符是非字母数字。validChars可以是任何构造,但我决定根据ascii代码范围选择删除控制字符。在此示例中,它是一个12个字符的字符串。
string validChars = String.Join("", Enumerable.Range(33, (126 - 33)).Where(i => !(new int[] { 34, 38, 39, 44, 60, 62, 96 }).Contains(i)).Select(i => { return (char)i; }));
string.Join("", Enumerable.Range(1, 12).Select(i => { return validChars[(new Random(Guid.NewGuid().GetHashCode())).Next(0, validChars.Length - 1)]; }))
Generate random password of specified length with
- Special characters
- Number
- Lowecase
- Uppercase
public static string CreatePassword(int length = 12)
{
const string lower = "abcdefghijklmnopqrstuvwxyz";
const string upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string number = "1234567890";
const string special = "!@#$%^&*";
var middle = length / 2;
StringBuilder res = new StringBuilder();
Random rnd = new Random();
while (0 < length--)
{
if (middle == length)
{
res.Append(number[rnd.Next(number.Length)]);
}
else if (middle - 1 == length)
{
res.Append(special[rnd.Next(special.Length)]);
}
else
{
if (length % 2 == 0)
{
res.Append(lower[rnd.Next(lower.Length)]);
}
else
{
res.Append(upper[rnd.Next(upper.Length)]);
}
}
}
return res.ToString();
}
public string CreatePassword(int length)
{
const string valid = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuilder res = new StringBuilder();
Random rnd = new Random();
while (0 < length--)
{
res.Append(valid[rnd.Next(valid.Length)]);
}
return res.ToString();
}
这具有很好的好处,能够从生成的密码的可用字符列表中进行选择(例如,仅数字,仅大写或仅小写等)。
我会在底池中添加另一个不明智的答案。
我有一个用例,我需要随机密码进行机器通信,因此我对人类可读性没有任何要求。我也没有在我的项目中访问Membership.GeneratePassword
,也不想添加依赖项。
我相当肯定Membership.GeneratePassword
正在做类似的事情,但在这里你可以调整要绘制的字符池。
public static class PasswordGenerator
{
private readonly static Random _rand = new Random();
public static string Generate(int length = 24)
{
const string lower = "abcdefghijklmnopqrstuvwxyz";
const string upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string number = "1234567890";
const string special = "!@#$%^&*_-=+";
// Get cryptographically random sequence of bytes
var bytes = new byte[length];
new RNGCryptoServiceProvider().GetBytes(bytes);
// Build up a string using random bytes and character classes
var res = new StringBuilder();
foreach(byte b in bytes)
{
// Randomly select a character class for each byte
switch (_rand.Next(4))
{
// In each case use mod to project byte b to the correct range
case 0:
res.Append(lower[b % lower.Count()]);
break;
case 1:
res.Append(upper[b % upper.Count()]);
break;
case 2:
res.Append(number[b % number.Count()]);
break;
case 3:
res.Append(special[b % special.Count()]);
break;
}
}
return res.ToString();
}
}
以及一些示例输出:
PasswordGenerator.Generate(12)
"pzY=64@-ChS$"
"BG0OsyLbYnI_"
"l9#5^2&adj_i"
"#++Ws9d$%O%X"
"IWhdIN-#&O^s"
为了抢占有关使用Random
的投诉:随机性的主要来源仍然是加密RNG。即使你可以确定地预先确定来自Random
的序列(假设它只产生1
),你仍然不会知道下一个将被挑选的焦点(尽管这会限制可能性的范围)。
一个简单的扩展是为不同的字符集添加权重,这可以像提高最大值一样简单,并添加通过案例来增加权重。
switch (_rand.Next(6))
{
// Prefer letters 2:1
case 0:
case 1:
res.Append(lower[b % lower.Count()]);
break;
case 2:
case 3:
res.Append(upper[b % upper.Count()]);
break;
case 4:
res.Append(number[b % number.Count()]);
break;
case 5:
res.Append(special[b % special.Count()]);
break;
}
对于更人性化的随机密码生成器,我曾经使用the EFF dice-word list实现了一个提示系统。
我使用此代码生成密码,其中包含字母,数字和non_alpha_numeric字符的余额组合。
public static string GeneratePassword(int Length, int NonAlphaNumericChars)
{
string allowedChars = "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ0123456789";
string allowedNonAlphaNum = "!@#$%^&*()_-+=[{]};:<>|./?";
string pass = "";
Random rd = new Random(DateTime.Now.Millisecond);
for (int i = 0; i < Length; i++)
{
if (rd.Next(1) > 0 && NonAlphaNumericChars > 0)
{
pass += allowedNonAlphaNum[rd.Next(allowedNonAlphaNum.Length)];
NonAlphaNumericChars--;
}
else
{
pass += allowedChars[rd.Next(allowedChars.Length)];
}
}
return pass;
}
插入一个Timer:timer1,2个按钮:button1,button2,1个textBox:textBox1和一个comboBox:comboBox1。请务必声明:
int count = 0;
源代码:
private void button1_Click(object sender, EventArgs e)
{
// This clears the textBox, resets the count, and starts the timer
count = 0;
textBox1.Clear();
timer1.Start();
}
private void timer1_Tick(object sender, EventArgs e)
{
// This generates the password, and types it in the textBox
count += 1;
string possible = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
string psw = "";
Random rnd = new Random { };
psw += possible[rnd.Next(possible.Length)];
textBox1.Text += psw;
if (count == (comboBox1.SelectedIndex + 1))
{
timer1.Stop();
}
}
private void Form1_Load(object sender, EventArgs e)
{
// This adds password lengths to the comboBox to choose from.
comboBox1.Items.Add("1");
comboBox1.Items.Add("2");
comboBox1.Items.Add("3");
comboBox1.Items.Add("4");
comboBox1.Items.Add("5");
comboBox1.Items.Add("6");
comboBox1.Items.Add("7");
comboBox1.Items.Add("8");
comboBox1.Items.Add("9");
comboBox1.Items.Add("10");
comboBox1.Items.Add("11");
comboBox1.Items.Add("12");
}
private void button2_click(object sender, EventArgs e)
{
// This encrypts the password
tochar = textBox1.Text;
textBox1.Clear();
char[] carray = tochar.ToCharArray();
for (int i = 0; i < carray.Length; i++)
{
int num = Convert.ToInt32(carray[i]) + 10;
string cvrt = Convert.ToChar(num).ToString();
textBox1.Text += cvrt;
}
}
public string Sifre_Uret(int boy, int noalfa)
{
// 01.03.2016
// Genel amaçlı şifre üretme fonksiyonu
//Fonskiyon 128 den büyük olmasına izin vermiyor.
if (boy > 128 ) { boy = 128; }
if (noalfa > 128) { noalfa = 128; }
if (noalfa > boy) { noalfa = boy; }
string passch = System.Web.Security.Membership.GeneratePassword(boy, noalfa);
//URL encoding ve Url Pass + json sorunu yaratabilecekler pass ediliyor.
//Microsoft Garanti etmiyor. Alfa Sayısallar Olabiliyorimiş . !@#$%^&*()_-+=[{]};:<>|./?.
//https://msdn.microsoft.com/tr-tr/library/system.web.security.membership.generatepassword(v=vs.110).aspx
//URL ve Json ajax lar için filtreleme
passch = passch.Replace(":", "z");
passch = passch.Replace(";", "W");
passch = passch.Replace("'", "t");
passch = passch.Replace("\"", "r");
passch = passch.Replace("/", "+");
passch = passch.Replace("\\", "e");
passch = passch.Replace("?", "9");
passch = passch.Replace("&", "8");
passch = passch.Replace("#", "D");
passch = passch.Replace("%", "u");
passch = passch.Replace("=", "4");
passch = passch.Replace("~", "1");
passch = passch.Replace("[", "2");
passch = passch.Replace("]", "3");
passch = passch.Replace("{", "g");
passch = passch.Replace("}", "J");
//passch = passch.Replace("(", "6");
//passch = passch.Replace(")", "0");
//passch = passch.Replace("|", "p");
//passch = passch.Replace("@", "4");
//passch = passch.Replace("!", "u");
//passch = passch.Replace("$", "Z");
//passch = passch.Replace("*", "5");
//passch = passch.Replace("_", "a");
passch = passch.Replace(",", "V");
passch = passch.Replace(".", "N");
passch = passch.Replace("+", "w");
passch = passch.Replace("-", "7");
return passch;
}
我的代码的主要目标是:
第一个属性是通过将64位值模数为字母大小来实现的。对于小字母(例如来自问题的62个字符),这导致可忽略的偏差。第二和第三个属性是通过使用RNGCryptoServiceProvider
而不是System.Random
实现的。
using System;
using System.Security.Cryptography;
public static string GetRandomAlphanumericString(int length)
{
const string alphanumericCharacters =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
"abcdefghijklmnopqrstuvwxyz" +
"0123456789";
return GetRandomString(length, alphanumericCharacters);
}
public static string GetRandomString(int length, IEnumerable<char> characterSet)
{
if (length < 0)
throw new ArgumentException("length must not be negative", "length");
if (length > int.MaxValue / 8) // 250 million chars ought to be enough for anybody
throw new ArgumentException("length is too big", "length");
if (characterSet == null)
throw new ArgumentNullException("characterSet");
var characterArray = characterSet.Distinct().ToArray();
if (characterArray.Length == 0)
throw new ArgumentException("characterSet must not be empty", "characterSet");
var bytes = new byte[length * 8];
new RNGCryptoServiceProvider().GetBytes(bytes);
var result = new char[length];
for (int i = 0; i < length; i++)
{
ulong value = BitConverter.ToUInt64(bytes, i * 8);
result[i] = characterArray[value % (uint)characterArray.Length];
}
return new string(result);
}
(这是我对How can I generate random 8 character, alphanumeric strings in C#?的回答的副本)
以下是我生成随机令牌的方法:
public string GenerateToken(int length)
{
RNGCryptoServiceProvider cryptRNG = new RNGCryptoServiceProvider();
byte[] tokenBuffer = new byte[length];
cryptRNG.GetBytes(tokenBuffer);
return Convert.ToBase64String(tokenBuffer);
}
已经注意到,当返回base-64字符串时,输出长度始终是4的倍数,使用=
作为填充字符的额外空间。 length
参数指定字节缓冲区的长度,而不是输出字符串(因此可能不是该参数的最佳名称,现在我考虑一下)。这可以控制密码的entropy字节数。但是,因为base-64使用一个4字符的块来编码每个3字节的输入,如果你要求的长度不是3的倍数,那么会有一些额外的“空格”,并且它将使用=
来填充额外的。
如果你不喜欢因任何原因使用base-64字符串,你可以用转换为常规字符串或任何Convert.ToBase64String()
方法替换Encoding
调用;例如。 Encoding.UTF8.GetString(tokenBuffer)
- 只需确保选择一个字符集,该字符集可以表示RNG中出现的所有值,并且可以生成与您发送或存储的任何位置兼容的字符。例如,使用Unicode往往会产生大量的中文字符。使用base-64可以保证广泛兼容的字符集,只要你使用一个像样的散列算法,这种字符串的特性就不会使它变得不那么安全。
这是一个更大的,但我认为它看起来更全面:http://www.obviex.com/Samples/Password.aspx
///////////////////////////////////////////////////////////////////////////////
// SAMPLE: Generates random password, which complies with the strong password
// rules and does not contain ambiguous characters.
//
// To run this sample, create a new Visual C# project using the Console
// Application template and replace the contents of the Class1.cs file with
// the code below.
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
// EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
//
// Copyright (C) 2004 Obviex(TM). All rights reserved.
//
using System;
using System.Security.Cryptography;
/// <summary>
/// This class can generate random passwords, which do not include ambiguous
/// characters, such as I, l, and 1. The generated password will be made of
/// 7-bit ASCII symbols. Every four characters will include one lower case
/// character, one upper case character, one number, and one special symbol
/// (such as '%') in a random order. The password will always start with an
/// alpha-numeric character; it will not start with a special symbol (we do
/// this because some back-end systems do not like certain special
/// characters in the first position).
/// </summary>
public class RandomPassword
{
// Define default min and max password lengths.
private static int DEFAULT_MIN_PASSWORD_LENGTH = 8;
private static int DEFAULT_MAX_PASSWORD_LENGTH = 10;
// Define supported password characters divided into groups.
// You can add (or remove) characters to (from) these groups.
private static string PASSWORD_CHARS_LCASE = "abcdefgijkmnopqrstwxyz";
private static string PASSWORD_CHARS_UCASE = "ABCDEFGHJKLMNPQRSTWXYZ";
private static string PASSWORD_CHARS_NUMERIC= "23456789";
private static string PASSWORD_CHARS_SPECIAL= "*$-+?_&=!%{}/";
/// <summary>
/// Generates a random password.
/// </summary>
/// <returns>
/// Randomly generated password.
/// </returns>
/// <remarks>
/// The length of the generated password will be determined at
/// random. It will be no shorter than the minimum default and
/// no longer than maximum default.
/// </remarks>
public static string Generate()
{
return Generate(DEFAULT_MIN_PASSWORD_LENGTH,
DEFAULT_MAX_PASSWORD_LENGTH);
}
/// <summary>
/// Generates a random password of the exact length.
/// </summary>
/// <param name="length">
/// Exact password length.
/// </param>
/// <returns>
/// Randomly generated password.
/// </returns>
public static string Generate(int length)
{
return Generate(length, length);
}
/// <summary>
/// Generates a random password.
/// </summary>
/// <param name="minLength">
/// Minimum password length.
/// </param>
/// <param name="maxLength">
/// Maximum password length.
/// </param>
/// <returns>
/// Randomly generated password.
/// </returns>
/// <remarks>
/// The length of the generated password will be determined at
/// random and it will fall with the range determined by the
/// function parameters.
/// </remarks>
public static string Generate(int minLength,
int maxLength)
{
// Make sure that input parameters are valid.
if (minLength <= 0 || maxLength <= 0 || minLength > maxLength)
return null;
// Create a local array containing supported password characters
// grouped by types. You can remove character groups from this
// array, but doing so will weaken the password strength.
char[][] charGroups = new char[][]
{
PASSWORD_CHARS_LCASE.ToCharArray(),
PASSWORD_CHARS_UCASE.ToCharArray(),
PASSWORD_CHARS_NUMERIC.ToCharArray(),
PASSWORD_CHARS_SPECIAL.ToCharArray()
};
// Use this array to track the number of unused characters in each
// character group.
int[] charsLeftInGroup = new int[charGroups.Length];
// Initially, all characters in each group are not used.
for (int i=0; i<charsLeftInGroup.Length; i++)
charsLeftInGroup[i] = charGroups[i].Length;
// Use this array to track (iterate through) unused character groups.
int[] leftGroupsOrder = new int[charGroups.Length];
// Initially, all character groups are not used.
for (int i=0; i<leftGroupsOrder.Length; i++)
leftGroupsOrder[i] = i;
// Because we cannot use the default randomizer, which is based on the
// current time (it will produce the same "random" number within a
// second), we will use a random number generator to seed the
// randomizer.
// Use a 4-byte array to fill it with random bytes and convert it then
// to an integer value.
byte[] randomBytes = new byte[4];
// Generate 4 random bytes.
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
rng.GetBytes(randomBytes);
// Convert 4 bytes into a 32-bit integer value.
int seed = BitConverter.ToInt32(randomBytes, 0);
// Now, this is real randomization.
Random random = new Random(seed);
// This array will hold password characters.
char[] password = null;
// Allocate appropriate memory for the password.
if (minLength < maxLength)
password = new char[random.Next(minLength, maxLength+1)];
else
password = new char[minLength];
// Index of the next character to be added to password.
int nextCharIdx;
// Index of the next character group to be processed.
int nextGroupIdx;
// Index which will be used to track not processed character groups.
int nextLeftGroupsOrderIdx;
// Index of the last non-processed character in a group.
int lastCharIdx;
// Index of the last non-processed group.
int lastLeftGroupsOrderIdx = leftGroupsOrder.Length - 1;
// Generate password characters one at a time.
for (int i=0; i<password.Length; i++)
{
// If only one character group remained unprocessed, process it;
// otherwise, pick a random character group from the unprocessed
// group list. To allow a special character to appear in the
// first position, increment the second parameter of the Next
// function call by one, i.e. lastLeftGroupsOrderIdx + 1.
if (lastLeftGroupsOrderIdx == 0)
nextLeftGroupsOrderIdx = 0;
else
nextLeftGroupsOrderIdx = random.Next(0,
lastLeftGroupsOrderIdx);
// Get the actual index of the character group, from which we will
// pick the next character.
nextGroupIdx = leftGroupsOrder[nextLeftGroupsOrderIdx];
// Get the index of the last unprocessed characters in this group.
lastCharIdx = charsLeftInGroup[nextGroupIdx] - 1;
// If only one unprocessed character is left, pick it; otherwise,
// get a random character from the unused character list.
if (lastCharIdx == 0)
nextCharIdx = 0;
else
nextCharIdx = random.Next(0, lastCharIdx+1);
// Add this character to the password.
password[i] = charGroups[nextGroupIdx][nextCharIdx];
// If we processed the last character in this group, start over.
if (lastCharIdx == 0)
charsLeftInGroup[nextGroupIdx] =
charGroups[nextGroupIdx].Length;
// There are more unprocessed characters left.
else
{
// Swap processed character with the last unprocessed character
// so that we don't pick it until we process all characters in
// this group.
if (lastCharIdx != nextCharIdx)
{
char temp = charGroups[nextGroupIdx][lastCharIdx];
charGroups[nextGroupIdx][lastCharIdx] =
charGroups[nextGroupIdx][nextCharIdx];
charGroups[nextGroupIdx][nextCharIdx] = temp;
}
// Decrement the number of unprocessed characters in
// this group.
charsLeftInGroup[nextGroupIdx]--;
}
// If we processed the last group, start all over.
if (lastLeftGroupsOrderIdx == 0)
lastLeftGroupsOrderIdx = leftGroupsOrder.Length - 1;
// There are more unprocessed groups left.
else
{
// Swap processed group with the last unprocessed group
// so that we don't pick it until we process all groups.
if (lastLeftGroupsOrderIdx != nextLeftGroupsOrderIdx)
{
int temp = leftGroupsOrder[lastLeftGroupsOrderIdx];
leftGroupsOrder[lastLeftGroupsOrderIdx] =
leftGroupsOrder[nextLeftGroupsOrderIdx];
leftGroupsOrder[nextLeftGroupsOrderIdx] = temp;
}
// Decrement the number of unprocessed groups.
lastLeftGroupsOrderIdx--;
}
}
// Convert password characters into a string and return the result.
return new string(password);
}
}
/// <summary>
/// Illustrates the use of the RandomPassword class.
/// </summary>
public class RandomPasswordTest
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
// Print 100 randomly generated passwords (8-to-10 char long).
for (int i=0; i<100; i++)
Console.WriteLine(RandomPassword.Generate(8, 10));
}
}
//
// END OF FILE
///////////////////////////////////////////////////////////////////////////////
我知道这是一个旧线程,但我有一个相当简单的解决方案供某人使用。易于实施,易于理解且易于验证。
考虑以下要求:
我需要生成一个随机密码,其中包含至少2个小写字母,2个大写字母和2个数字。密码长度也必须至少为8个字符。
以下正则表达式可以验证此情况:
^(?=\b\w*[a-z].*[a-z]\w*\b)(?=\b\w*[A-Z].*[A-Z]\w*\b)(?=\b\w*[0-9].*[0-9]\w*\b)[a-zA-Z0-9]{8,}$
这超出了这个问题的范围 - 但正则表达式基于lookahead/lookbehind和lookaround。
以下代码将创建符合此要求的随机字符集:
public static string GeneratePassword(int lowercase, int uppercase, int numerics) {
string lowers = "abcdefghijklmnopqrstuvwxyz";
string uppers = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string number = "0123456789";
Random random = new Random();
string generated = "!";
for (int i = 1; i <= lowercase; i++)
generated = generated.Insert(
random.Next(generated.Length),
lowers[random.Next(lowers.Length - 1)].ToString()
);
for (int i = 1; i <= uppercase; i++)
generated = generated.Insert(
random.Next(generated.Length),
uppers[random.Next(uppers.Length - 1)].ToString()
);
for (int i = 1; i <= numerics; i++)
generated = generated.Insert(
random.Next(generated.Length),
number[random.Next(number.Length - 1)].ToString()
);
return generated.Replace("!", string.Empty);
}
要满足上述要求,只需拨打以下电话:
String randomPassword = GeneratePassword(3, 3, 3);
代码以无效字符("!"
)开头 - 这样字符串就有一个可以注入新字符的长度。
然后它从1循环到所需的小写字符数,并在每次迭代时,从小写列表中抓取一个随机项,并将其注入字符串中的随机位置。
然后它重复循环以获得大写字母和数字。
这将返回长度= lowercase + uppercase + numerics
的字符串,其中所需计数的小写,大写和数字字符以随机顺序放置。
我创建了使用RNGCryptoServiceProvider的this class,它非常灵活。例:
var generator = new PasswordGenerator(minimumLengthPassword: 8,
maximumLengthPassword: 15,
minimumUpperCaseChars: 2,
minimumNumericChars: 3,
minimumSpecialChars: 2);
string password = generator.Generate();
对于这种密码,我倾向于使用一个可能生成更容易“使用”密码的系统。简短,通常由可发音的片段和一些数字组成,没有字符间歧义(是0还是O?A 1还是I?)。就像是
string[] words = { 'bur', 'ler', 'meh', 'ree' };
string word = "";
Random rnd = new Random();
for (i = 0; i < 3; i++)
word += words[rnd.Next(words.length)]
int numbCount = rnd.Next(4);
for (i = 0; i < numbCount; i++)
word += (2 + rnd.Next(7)).ToString();
return word;
(直接键入浏览器,因此仅用作指南。另外,添加更多单词)。
我不喜欢Membership.GeneratePassword()创建的密码,因为它们太难看并且有太多特殊字符。
此代码生成一个10位数的不太丑的密码。
string password = Guid.NewGuid().ToString("N").ToLower()
.Replace("1", "").Replace("o", "").Replace("0","")
.Substring(0,10);
当然,我可以使用正则表达式进行所有替换,但这是更易读和可维护的IMO。