我在登录时使用相同的函数来哈希值进行比较,因为我在用户注册时哈希密码:
Public Shared Function Compute(ByVal text As String, ByVal algorithm As String, Optional ByVal salt() As Byte = Nothing) As String
If salt Is Nothing Then
Dim saltSize As Integer = 8
salt = New Byte(saltSize - 1) {}
Dim rng As New RNGCryptoServiceProvider
rng.GetNonZeroBytes(salt)
End If
Dim textBytes As Byte() = Encoding.UTF8.GetBytes(text)
Dim saltedTextBytes() As Byte = New Byte(textBytes.Length + salt.Length - 1) {}
For i As Integer = 0 To textBytes.Length - 1
saltedTextBytes(i) = textBytes(i)
Next i
For i As Integer = 0 To salt.Length - 1
saltedTextBytes(textBytes.Length + i) = salt(i)
Next i
Dim hash As HashAlgorithm
If algorithm Is Nothing Then
algorithm = ""
End If
Select Case algorithm.ToUpper
Case "SHA1" : hash = New SHA1Managed
Case "SHA256" : hash = New SHA256Managed
Case "SHA384" : hash = New SHA384Managed
Case "SHA512" : hash = New SHA512Managed
Case Else : hash = New MD5CryptoServiceProvider
End Select
Dim hashBytes As Byte() = hash.ComputeHash(saltedTextBytes)
Dim saltedHash() As Byte = New Byte(hashBytes.Length + salt.Length - 1) {}
For i As Integer = 0 To hashBytes.Length - 1
saltedHash(i) = hashBytes(i)
Next i
For i As Integer = 0 To salt.Length - 1
saltedHash(hashBytes.Length + i) = salt(i)
Next i
Dim hashValue As String = Convert.ToBase64String(saltedHash)
Return Left(hashValue, 36)
End Function
我的问题是,当我尝试登录其密码被此函数哈希的帐户时,哈希值不匹配。我想我正在跳过一步或什么的。
以下是用户帐户创建的代码:
' The email address needs to be valid
Dim pattern As String = "^(?("")("".+?""@)|(([0-9a-zA-Z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-zA-Z])@))(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,6}))$"
Dim match As Match = Regex.Match(txtEmail.Text, pattern)
If match.Success Then
'Hash the user's password before entering it into the database.
Dim pass As String = Crypt.Compute(txtPass.Text, "SHA512", Nothing)
' Enter the information from the form into the database.
Dim sql As String = "INSERT INTO Users(Username, Password, EmailAddress) " & _
"VALUES(@User, @Pass, @Email)"
Dim cmd As New SqlCommand(sql, conn)
cmd.Parameters.AddWithValue("@User", txtName.Text)
cmd.Parameters.AddWithValue("@Pass", pass)
cmd.Parameters.AddWithValue("@Email", txtEmail.Text)
conn.Open()
cmd.ExecuteNonQuery()
conn.Close()
Else
lblError.Text = "Invalid email address. Please correct."
lblError.ForeColor = Drawing.Color.Red
End If
此处未包含的更多检查与我的问题无关。
这是我的用户登录信息:
Dim pass As String = Crypt.Compute(txtPass.Text, "SHA512", Nothing)
Dim UserData As New DataSet
Dim UserAdapter As New SqlDataAdapter
UserAdapter.SelectCommand = New SqlCommand("SELECT * FROM Users " & _
"WHERE Username = @User AND Password = @Pass", conn)
UserAdapter.SelectCommand.Parameters.AddWithValue("@User", txtUser.Text)
UserAdapter.SelectCommand.Parameters.AddWithValue("@Pass", pass)
UserAdapter.Fill(UserData)
If UserData.Tables(0).Rows.Count <> 1 Then
lblError.Text = "Invalid username or password."
lblError.ForeColor = Drawing.Color.Red
Session("LoginAttempt") = CInt(Session("LoginAttempt")) + 1
Else
Session("LoggedIn") = True
Response.Redirect("Home.aspx")
End If
据我所知,我在这里做的散列没有区别。
有没有人有任何想法?
答案 0 :(得分:3)
txtName.Text
作为用户名,但在检查您使用的凭据时txtUser.Text
。你为什么要使用随机盐?每次加密的盐都不一样吗?我已将您的代码粘贴到一个新项目中,当我连续两次运行Compute
方法获取相同的密码时,我得到两个不同的结果......显然这不起作用。尝试传入salt值而不是Nothing
,并使用相同的salt创建帐户并比较登录。以下是一些有效的示例代码:
Dim thePass As String = "MyPassword"
Dim theSalt As String = "salt"
Dim pass As String = Compute(thePass, "SHA512", Encoding.UTF8.GetBytes(theSalt))
Console.WriteLine(pass)
Dim pass2 As String = Compute(thePass, "SHA512", Encoding.UTF8.GetBytes(theSalt))
Console.WriteLine(pass2) 'pass and pass2 are identical
希望这有帮助!
答案 1 :(得分:2)
除非我错过了(不熟悉这种语言),否则你不会把盐存放在任何地方。
您必须使用在创建验证帐户时使用的相同盐。
旁注:您可以为每个用户帐户生成随机盐,也可以为所有帐户使用固定盐。两种方法都有效。第一个在理论上更安全,但如果盐足够长,两者都可以用于实际目的。