Can't install inspec due to a sha256 error (Cannot find type)

Question

I am trying to install inspec in powershell and during the install I am receiving an error.

Cannot find type [Security.Cryptography.SHA256Cng]: verify that the assembly containing this type is loaded.

The current version of powershell is 7.

The install command being used is.

. { iwr -useb https://omnitruck.chef.io/install.ps1 } | iex; install -project inspec

It installs ok on the windows powershell version 5.1 but it doesn't on the downloaded and installed version of powershell 7.4.1

I have tried hashing something using sha256 and it works ok.

Answer 1

The issue is that SHA256Cng Class only exists .NET Framework and PowerShell 7+ uses .NET, if you wanted to make it work, the function having a reference to that class is Get-SHA256Converter and you could change it to this to make it compatible with both versions:

function Get-SHA256Converter {
    if ($IsCoreCLR) {
        return [System.Security.Cryptography.SHA256]::Create()
    }

    if ((Is-FIPS) -ge 1) {
        return [Security.Cryptography.SHA256Cng]::new()
    }

    [Security.Cryptography.SHA256Managed]::new()
}