我想创建一个密码生成器，根据用户设置的限制创建密码。限制是：
我通过谷歌了解，大部分示例代码都不符合我的要求。所以我即兴发布了这样的代码：
private char[] GeneratePassword(int minLength, int maxLength,
int maxRepeatCharacter, int minLetterAndDigit, int minLetter,
int minLowerCaseLetter, int minUpperCaseLetter, int minDigit) {
final String LETTER = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
final String UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
final String LOWERCASE = "abcdefghijklmnopqrstuvwxyz";
final String DIGIT = "0123456789";
final String[] randomSelector = {LETTER,UPPERCASE,LOWERCASE,DIGIT};
int len = getRandomNumber(minLength, maxLength);
char[] passwordGenerated = new char[len];
char[] characterUsed = new char[len];
int selection;
int letterAndDigitUsed = 0;
int letterUsed = 0;
int lowerCaseLetterUsed = 0;
int upperCaseLetterUsed = 0;
int digitUsed = 0;
int index = 0;
if (minLength > maxLength) {
// throw new IllegalArgumentException("Min.Length > Max.Length!");
}
if (minLetter + minDigit > minLetterAndDigit) {
// throw new IllegalArgumentException("Error!");
}
while (index != len) {
selection = getRandomNumber(0, randomSelector.length);
if (selection == 0) {
passwordGenerated[index] = LETTER.charAt(RandomUtils.nextInt(0,
LETTER.length()));
if (checkRepeatCharacter(passwordGenerated[index],
characterUsed, index, maxRepeatCharacter) == false) {
characterUsed[index] = passwordGenerated[index];
index++;
letterUsed++;
letterAndDigitUsed++;
break;
}
} else if (selection == 1) {
passwordGenerated[index] = UPPERCASE.charAt(RandomUtils
.nextInt(0, UPPERCASE.length()));
if (checkRepeatCharacter(passwordGenerated[index],
characterUsed, index, maxRepeatCharacter) == false) {
characterUsed[index] = passwordGenerated[index];
index++;
upperCaseLetterUsed++;
letterAndDigitUsed++;
break;
}
} else if (selection == 2) {
passwordGenerated[index] = LOWERCASE.charAt(RandomUtils
.nextInt(0, LOWERCASE.length()));
if (checkRepeatCharacter(passwordGenerated[index],
characterUsed, index, maxRepeatCharacter) == false) {
characterUsed[index] = passwordGenerated[index];
index++;
lowerCaseLetterUsed++;
letterAndDigitUsed++;
break;
}
} else if (selection == 3) {
passwordGenerated[index] = DIGIT.charAt(RandomUtils.nextInt(0,
DIGIT.length()));
if (checkRepeatCharacter(passwordGenerated[index],
characterUsed, index, maxRepeatCharacter) == false) {
characterUsed[index] = passwordGenerated[index];
index++;
digitUsed++;
letterAndDigitUsed++;
break;
}
}
}
return passwordGenerated;
}
private boolean checkRepeatCharacter(char passwordGenerated,
char[] passwordUsed, int index, int maxRepeatCharacter) {
int characterRepeated = 0;
for (int i = 0; i < index; i++) {
if (String.valueOf(passwordUsed[i]).equals(
String.valueOf(passwordGenerated))) {
characterRepeated++;
if (characterRepeated == maxRepeatCharacter) {
return true;
}
}
}
return false;
}
private int getRandomNumber(int minLength, int maxLength) {
Random r = new Random();
return r.nextInt(maxLength - minLength) + minLength;
}
我遇到的问题是如何确保达到最低条件。与此同时，我不希望通过重复使用相同类型的角色来生成密码。
示例：如果我将最大密码长度设置为10，并且我希望最小数字为5.我更喜欢1jP2k3o4m9而不是57812aJ9tP。
第二个示例：如果我将最大密码长度设置为5，并且我希望最小小写字母为3.我更喜欢Pj9mn而不是jkl5V。
如您所见，第二个生成的密码首先尝试满足最低要求，然后只对其他字符类型进行随机选择。这将使密码更容易受到攻击。有没有办法做这个算法。
答案 0 :(得分：2)
我会看一下像vt-password这样的东西：
https://code.google.com/p/vt-middleware/wiki/vtpassword
除了根据一些相当标准的必需特性提供灵活的密码验证机制外，它还支持生成符合“字符规则”列表所定义条件的密码：
https://code.google.com/p/vt-middleware/wiki/vtpassword#Generating_passwords
值得注意的是，该项目已经从孵化中毕业，现在被称为Passay - http://www.passay.org/。
当前password generator JavaDocs不反映vt-password可用的同一组字符规则。您可以使用vt-password运行一段时间，也可以提供自己的$request='{ "weight": 0, "precondition": "{\"_deviceId._SerialNumber\":\"C8Bjkjkjj5E372\"}", "configurations": [ { "type": "value", "name": "InternetGatewayDevice.Time.NTPServer1", "value": "ntp1.sssdssd.com" }, { "type": "value", "name": "InternetGatewayDevice.Time.NTPServer3", "value": "ntp.dfdfkdshfksfd.org" } ] }';
$location='http://localhost:7557/presets/inform';
$response=curlRequest($request,$location);
function curlRequest($request, $location)
{
$ch = curl_init($location);
$curlOptions = array(
CURLOPT_URL => $location,
// CURLOPT_RETURNTRANSFER => true,
// CURLOPT_FOLLOWLOCATION => true,
// CURLOPT_MAXREDIRS => 10,
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => $request,
CURLOPT_PROXY => 'proxy.example.com',
CURLOPT_PROXYPORT => 8080 ,
CURLOPT_TIMEOUT => SOAP_CONN_TIMEOUT,
CURLOPT_SSLVERSION => 3,
CURLOPT_SSL_VERIFYPEER => false,
);
//
curl_setopt_array($ch, $curlOptions);
$response = curl_exec($ch) or die (curl_error($ch));
return $response;
}
实现来使用Passay生成器（+验证器，如果也需要）。
答案 1 :(得分：1)
我修复了我的代码。到目前为止，我已经测试过，我按要求完美运行。我留下这段代码以防万一其他人将来需要它。
private boolean checkRepeatCharacter(char randomCharacter,
ArrayList<Character> passwordUsed, int usedLength,
int maxRepeatCharacter) {
int characterRepeated = 0;
for (int i = 0; i < usedLength; i++) {
if (String.valueOf(passwordUsed.get(i)).equals(
String.valueOf(randomCharacter))) {
characterRepeated++;
if (characterRepeated == maxRepeatCharacter) {
return false;
}
}
}
return true;
}
private boolean checkUsedIndex(int index, ArrayList<Integer> usedIndex) {
for (int i = 0; i < usedIndex.size(); i++) {
if (usedIndex.contains(index)) {
return false;
}
}
return true;
}
private int getRandomNumber(int minLength, int maxLength) {
Random r = new Random();
return r.nextInt(maxLength - minLength) + minLength;
}
public String generatePassword(int minLength, int maxLength,
int maxRepeatCharacter, int minLetterAndDigit, int minLetter,
int minLowerCaseLetter, int minUpperCaseLetter, int minDigit,
int minSpecialCharacter, String specialCharacter) {
final String LOWERCASE = "abcdefghijklmnopqrstuvwxyz";
final String UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
final String DIGIT = "0123456789";
StringBuilder ALL = new StringBuilder();
ALL.append(LOWERCASE);
ALL.append(UPPERCASE);
ALL.append(DIGIT);
ALL.append(specialCharacter);
ALL.toString();
char getRandom;
int length = 0;
StringBuilder passwordGenerated = new StringBuilder();
ArrayList<Character> characterUsed = new ArrayList<Character>();
ArrayList<Integer> indexUsed = new ArrayList<Integer>();
int passwordLength = 0;
int lowerCaseLetterUsed = 0;
int upperCaseLetterUsed = 0;
int letterUsed = 0;
int digitUsed = 0;
int letterAndDigitUsed = 0;
int specialCharacterUsed = 0;
if (minLength > maxLength) {
throw new IllegalArgumentException("Min. Length > Max. Length!");
}
if (minUpperCaseLetter + minLowerCaseLetter > minLetter) {
throw new RuntimeException(
"mininimum Lower Case + Minimum Uppercase cannot exceed minLetter");
}
if (minLetter + minDigit > minLetterAndDigit) {
throw new RuntimeException(
"mininimum Letter + Minimum Digit cannot exceed minimum Letter And Digit");
}
if (minLetter + minDigit + minSpecialCharacter > maxLength) {
throw new RuntimeException(
"minimum Digit + minimum Letter + Minimum Special Character cannot excced maximum Length");
}
while ((length < minLetter) && (length < minLetterAndDigit)) {
length = getRandomNumber(minLength, maxLength);
}
while (passwordLength != length) {
while (letterAndDigitUsed < minLetterAndDigit) {
while (letterUsed < minLetter) {
lowerCaseLetterUsed = 0;
for (int i = 0; lowerCaseLetterUsed < minLowerCaseLetter; i++) {
int index = getRandomNumber(0, length);
if (checkUsedIndex(index, indexUsed) == true) {
getRandom = LOWERCASE.charAt(getRandomNumber(0,
LOWERCASE.length()));
if (checkRepeatCharacter(getRandom, characterUsed,
characterUsed.size(), maxRepeatCharacter) == true) {
passwordGenerated.append(getRandom);
characterUsed.add(getRandom);
indexUsed.add(index);
lowerCaseLetterUsed++;
letterUsed++;
letterAndDigitUsed++;
passwordLength++;
if (letterUsed == minLetter) {
break;
}
}
}
}
if (letterAndDigitUsed == minLetterAndDigit) {
break;
}
upperCaseLetterUsed = 0;
for (int i = 0; upperCaseLetterUsed < minUpperCaseLetter; i++) {
int index = getRandomNumber(0, length);
if (checkUsedIndex(index, indexUsed) == true) {
getRandom = UPPERCASE.charAt(getRandomNumber(0,
UPPERCASE.length()));
if (checkRepeatCharacter(getRandom, characterUsed,
characterUsed.size(), maxRepeatCharacter) == true) {
passwordGenerated.append(getRandom);
characterUsed.add(getRandom);
indexUsed.add(index);
lowerCaseLetterUsed++;
letterUsed++;
letterAndDigitUsed++;
passwordLength++;
if (letterUsed == minLetter) {
break;
}
}
}
}
if (letterAndDigitUsed == minLetterAndDigit) {
break;
}
}
for (int i = 0; digitUsed < minDigit; i++) {
int index = getRandomNumber(0, length);
if (checkUsedIndex(index, indexUsed) == true) {
getRandom = DIGIT.charAt(getRandomNumber(0,
DIGIT.length()));
if (checkRepeatCharacter(getRandom, characterUsed,
characterUsed.size(), maxRepeatCharacter) == true) {
passwordGenerated.append(getRandom);
characterUsed.add(getRandom);
indexUsed.add(index);
digitUsed++;
letterAndDigitUsed++;
passwordLength++;
}
}
}
}
for (int i = 0; specialCharacterUsed < minSpecialCharacter; i++) {
if (checkUsedIndex(i, indexUsed) == true) {
getRandom = specialCharacter.charAt(getRandomNumber(0,
specialCharacter.length()));
if (checkRepeatCharacter(getRandom, characterUsed,
characterUsed.size(), maxRepeatCharacter) == true) {
passwordGenerated.append(getRandom);
characterUsed.add(getRandom);
indexUsed.add(i);
specialCharacterUsed++;
passwordLength++;
}
}
}
for (int i = 0; i < length; i++) {
if (checkUsedIndex(i, indexUsed) == true) {
getRandom = ALL.charAt(getRandomNumber(0, ALL.length()));
if (checkRepeatCharacter(getRandom, characterUsed,
characterUsed.size(), maxRepeatCharacter) == true) {
passwordGenerated.append(getRandom);
characterUsed.add(getRandom);
indexUsed.add(i);
passwordLength++;
}
}
}
}
return passwordGenerated.toString();
}