Gerar Strings Randomicas

[DiFalco 0]

galera...preciso de um código q gere uma String de forma randômica, pq no meu sistema vai ser cadastrado o Usuário por um Administrador e o sistema terá q gerar uma senha de forma randômica.. alguém um código pra isso??[]'s

[Tiago Colombo 0]

Olá,pq você não usa Hash??[]'s

[DiFalco 0]

como se usa isso ??? realmente nao sei...

[DiFalco 0]

descobri como

 

segue o código pra galera:

 

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' 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 Basic.NET project using the Console' Application template and replace the contents of the Module1.vb 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) Obviex(TM). All rights reserved.' Imports SystemImports 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 Shared DEFAULT_MIN_PASSWORD_LENGTH As Integer = 8	Private Shared DEFAULT_MAX_PASSWORD_LENGTH As Integer = 10	' Define supported password characters divided into groups.	' You can add (or remove) characters to (from) these groups.	Private Shared PASSWORD_CHARS_LCASE As String = "abcdefgijkmnopqrstwxyz"	Private Shared PASSWORD_CHARS_UCASE As String = "ABCDEFGHJKLMNPQRSTWXYZ"	Private Shared PASSWORD_CHARS_NUMERIC As String = "23456789"	'Private Shared PASSWORD_CHARS_SPECIAL As String = "*$-+?_&=!%{}/"	' <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 Shared Function Generate() As String		Generate = Generate(DEFAULT_MIN_PASSWORD_LENGTH, _							DEFAULT_MAX_PASSWORD_LENGTH)	End Function	' <summary>	' Generates a random password of the exact length.	' </summary>	' <param name="length">	' Exact password length.	' </param>	' <returns>	' Randomly generated password.	' </returns>	Public Shared Function Generate(ByVal length As Integer) As String		Generate = Generate(length, length)	End Function	' <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 Shared Function Generate(ByVal minLength As Integer, _	ByVal maxLength As Integer) _		As String		' Make sure that input parameters are valid.		If (minLength <= 0 Or maxLength <= 0 Or minLength > maxLength) Then			Generate = Nothing		End If		' 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.		Dim charGroups As Char()() = New Char()() _		{ _			PASSWORD_CHARS_LCASE.ToCharArray(), _			PASSWORD_CHARS_UCASE.ToCharArray(), _			PASSWORD_CHARS_NUMERIC.ToCharArray() _		}		' Use this array to track the number of unused characters in each		' character group.		Dim charsLeftInGroup As Integer() = New Integer(charGroups.Length - 1) {}		' Initially, all characters in each group are not used.		Dim I As Integer		For I = 0 To charsLeftInGroup.Length - 1			charsLeftInGroup(I) = charGroups(I).Length		Next		' Use this array to track (iterate through) unused character groups.		Dim leftGroupsOrder As Integer() = New Integer(charGroups.Length - 1) {}		' Initially, all character groups are not used.		For I = 0 To leftGroupsOrder.Length - 1			leftGroupsOrder(I) = I		Next		' 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.		Dim randomBytes As Byte() = New Byte(3) {}		' Generate 4 random bytes.		Dim rng As RNGCryptoServiceProvider = New RNGCryptoServiceProvider		rng.GetBytes(randomBytes)		' Convert 4 bytes into a 32-bit integer value.		Dim seed As Integer = ((randomBytes(0) And &H7F) << 24 Or _								randomBytes(1) << 16 Or _								randomBytes(2) << 8 Or _								randomBytes(3))		' Now, this is real randomization.		Dim random As Random = New Random(seed)		' This array will hold password characters.		Dim password As Char() = Nothing		' Allocate appropriate memory for the password.		If (minLength < maxLength) Then			password = New Char(random.Next(minLength - 1, maxLength)) {}		Else			password = New Char(minLength - 1) {}		End If		' Index of the next character to be added to password.		Dim nextCharIdx As Integer		' Index of the next character group to be processed.		Dim nextGroupIdx As Integer		' Index which will be used to track not processed character groups.		Dim nextLeftGroupsOrderIdx As Integer		' Index of the last non-processed character in a group.		Dim lastCharIdx As Integer		' Index of the last non-processed group.		Dim lastLeftGroupsOrderIdx As Integer = leftGroupsOrder.Length - 1		' Generate password characters one at a time.		For I = 0 To password.Length - 1			' 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) Then				nextLeftGroupsOrderIdx = 0			Else				nextLeftGroupsOrderIdx = random.Next(0, lastLeftGroupsOrderIdx)			End If			' 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) Then				nextCharIdx = 0			Else				nextCharIdx = random.Next(0, lastCharIdx + 1)			End If			' 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) Then				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) Then					Dim temp As Char = charGroups(nextGroupIdx)(lastCharIdx)					charGroups(nextGroupIdx)(lastCharIdx) = _								charGroups(nextGroupIdx)(nextCharIdx)					charGroups(nextGroupIdx)(nextCharIdx) = temp				End If				' Decrement the number of unprocessed characters in				' this group.				charsLeftInGroup(nextGroupIdx) = _						   charsLeftInGroup(nextGroupIdx) - 1			End If			' If we processed the last group, start all over.			If (lastLeftGroupsOrderIdx = 0) Then				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) Then					Dim temp As Integer = _								leftGroupsOrder(lastLeftGroupsOrderIdx)					leftGroupsOrder(lastLeftGroupsOrderIdx) = _								leftGroupsOrder(nextLeftGroupsOrderIdx)					leftGroupsOrder(nextLeftGroupsOrderIdx) = temp				End If				' Decrement the number of unprocessed groups.				lastLeftGroupsOrderIdx = lastLeftGroupsOrderIdx - 1			End If		Next		' Convert password characters into a string and return the result.		Generate = New String(password)	End FunctionEnd Class