Azure ARM uniqueString function mimic

问题

I need to deploy Sql Databases into an Azure Sql Server using to ways: the ARM template way, and a more custom way using C# code. There's a ARM template function called uniqueString(string) that generate a pseudo random hash of a given string. It's a deterministic pure function.

I need to find a way to exactly mimic the behaviour of this function from my C# code. ie I need to reproduce this function into my C# code.

Where can i find the algorithm used by the ARM Api ?

MSDN reference for uniqueString()

回答1:

I found some PowerShell code to do this here: https://blogs.technet.microsoft.com/389thoughts/2017/12/23/get-uniquestring-generate-unique-id-for-azure-deployments/

I converted this code to C#:

public string GetUniqueString(string id, int length = 13)
{
    string result = "";
    var buffer = System.Text.Encoding.UTF8.GetBytes(id);
    var hashArray = new System.Security.Cryptography.SHA512Managed().ComputeHash(buffer);
    for(int i = 1; i <= length; i++)
    {
        var b = hashArray[i];
        var c = Convert.ToChar((b % 26) + (byte)'a');
        result = result + c;
    }

    return result;
}

回答2:

I finally found a workaround. I used a very simple ARM template which goal is to only output the result of the uniqueStringcommand. Then I fetch this output in my C# code. This solution is not really the quickest one ;-), but it works as desired.

来源：https://stackoverflow.com/questions/43295720/azure-arm-uniquestring-function-mimic