Question

使用SNMP版本3，我正在创建一个用户。现在，我已经设置了克隆用户的地方，并且工作得很好。但是，我需要更改新用户的authKey。我怎样才能做到这一点？我知道authKeyChange的oid，但是，我不知道如何生成新密钥。如何生成该密钥？可以使用SNMPSharpNet完成吗？如果在创建用户时有更简单的方法，我也可以这样做。任何更改authKey（和privKey，但一次一步）的方法都非常感谢。如果有任何意义，我正在使用VB.net。

Answer 1

所以我想出了如何做到这一点。这是一个复杂的过程。我关注了this文件，即rfc2574。对“keyChange :: =”执行ctrl + F，然后您将找到引导您完成算法的段落以生成keyChange值。以下代码可靠地生成keyChange值。从这一点开始，您只需将keyChange值推送到usmAuthKeyChange OID即可。如果要更改隐私密码，请将keyChange值推送到usmPrivKeyChange OID。我很惭愧地说，由于时间紧迫，我没有时间完全完成这项工作，所以当使用SHA时，我不得不编写一个全新的方法来完成几乎完全相同的事情。再一次，我很惭愧发布它，但我知道我是多么把头撞在墙上，如果有人来这里看到这个，我希望他们知道该做什么而不经过斗争。 / p>

以下是使用VB.Net和SNMPSharpNet库所需的所有代码：

Private Function GenerateKeyChange(ByVal newPass As String, ByVal oldPass As String, ByRef target As UdpTarget, ByRef param As SecureAgentParameters) As Byte()

    Dim authProto As AuthenticationDigests = param.Authentication
    Dim hash As IAuthenticationDigest = Authentication.GetInstance(authProto)
    Dim L As Integer = hash.DigestLength
    Dim oldKey() As Byte = hash.PasswordToKey(Encoding.UTF8.GetBytes(oldPass), param.EngineId)
    Dim newKey() As Byte = hash.PasswordToKey(Encoding.UTF8.GetBytes(newPass), param.EngineId)
    Dim random() As Byte = Encoding.UTF8.GetBytes(GenerateRandomString(L))
    Dim temp() As Byte = oldKey
    Dim delta(L - 1) As Byte
    Dim iterations As Integer = ((newKey.Length - 1) / L) - 1
    Dim k As Integer = 0
    If newKey.Length > L Then
        For k = 0 To iterations

            'Append random to temp
            Dim merged1(temp.Length + random.Length - 1) As Byte
            temp.CopyTo(merged1, 0)
            random.CopyTo(merged1, random.Length)

            'Store hash of temp in itself
            temp = hash.ComputeHash(merged1, 0, merged1.Length)

            'Generate the first 16 values of delta
            For i = 0 To L - 1
                delta(k * L + i) = temp(i) Xor newKey(k * L + i)
            Next
        Next
    End If

    'Append random to temp
    Dim merged(temp.Length + random.Length - 1) As Byte
    temp.CopyTo(merged, 0)
    random.CopyTo(merged, temp.Length)

    'Store hash of temp in itself
    temp = hash.ComputeHash(merged, 0, merged.Length)

    'Generate the first 16 values of delta
    For i = 0 To (newKey.Length - iterations * L) - 1
        delta(iterations * L + i) = temp(i) Xor newKey(iterations * L + i)
    Next

    Dim keyChange(delta.Length + random.Length - 1) As Byte
    random.CopyTo(keyChange, 0)
    delta.CopyTo(keyChange, random.Length)
    Return keyChange
End Function

Private Function GenerateKeyChangeShaSpecial(ByVal newPass As String, ByVal oldPass As String, ByRef target As UdpTarget, ByRef param As SecureAgentParameters) As Byte()

    Dim authProto As AuthenticationDigests = param.Authentication
    Dim hash As IAuthenticationDigest = Authentication.GetInstance(authProto)
    Dim L As Integer = 16

    Dim oldKey() As Byte = hash.PasswordToKey(Encoding.UTF8.GetBytes(oldPass), param.EngineId)
    Dim newKey() As Byte = hash.PasswordToKey(Encoding.UTF8.GetBytes(newPass), param.EngineId)

    Array.Resize(oldKey, L)
    Array.Resize(newKey, L)

    Dim random() As Byte = Encoding.UTF8.GetBytes(GenerateRandomString(L))
    Dim temp() As Byte = oldKey
    Dim delta(L - 1) As Byte
    Dim iterations As Integer = ((newKey.Length - 1) / L) - 1
    Dim k As Integer = 0
    If newKey.Length > L Then
        For k = 0 To iterations
            'Append random to temp
            Dim merged1(temp.Length + random.Length - 1) As Byte
            temp.CopyTo(merged1, 0)
            random.CopyTo(merged1, random.Length)

            'Store hash of temp in itself
            temp = hash.ComputeHash(merged1, 0, merged1.Length)
            Array.Resize(temp, L)

            'Generate the first 16 values of delta
            For i = 0 To L - 1
                delta(k * L + i) = temp(i) Xor newKey(k * L + i)
            Next
        Next
    End If

    'Append random to temp
    Dim merged(temp.Length + random.Length - 1) As Byte
    temp.CopyTo(merged, 0)
    random.CopyTo(merged, temp.Length)

    'Store hash of temp in itself
    temp = hash.ComputeHash(merged, 0, merged.Length)
    Array.Resize(temp, L)

    'Generate the first 16 values of delta
    For i = 0 To (newKey.Length - iterations * L) - 1
        delta(iterations * L + i) = temp(i) Xor newKey(iterations * L + i)
    Next

    Dim keyChange(delta.Length + random.Length - 1) As Byte
    random.CopyTo(keyChange, 0)
    delta.CopyTo(keyChange, random.Length)
    Return keyChange
End Function

Private Function GenerateRandomString(ByVal length As Integer) As String
    Dim s As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
    Dim r As New Random
    Dim sb As New StringBuilder
    For i As Integer = 1 To length
        Dim idx As Integer = r.Next(0, 51)
        sb.Append(s.Substring(idx, 1))
    Next
    Return sb.ToString()
End Function

同样，我很清楚这段代码很可怕，但是它有效，而这就是我需要的所有内容。我知道这是技术债务而不是我应该编码的方式，但它就在这里，我希望你能从中得到一些用处。

如果这不起作用，请不要忘记转到frc2574并查看算法。

更改用户的authKey

1 个答案: