Powershell v3 Invoke-WebRequest HTTPS error

This work-around worked for me:http://connect.microsoft.com/PowerShell/feedback/details/419466/new-webserviceproxy-needs-force-parameter-to-ignore-ssl-errors

Basically, in your PowerShell script:

add-type @"    using System.Net;    using System.Security.Cryptography.X509Certificates;    public class TrustAllCertsPolicy : ICertificatePolicy {        public bool CheckValidationResult(            ServicePoint srvPoint, X509Certificate certificate,            WebRequest request, int certificateProblem) {            return true;        }    }"@[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy$result = Invoke-WebRequest -Uri "https://IpAddress/resource"

Lee's answer is great, but I also had issues with which protocols the web server supported.
After also adding the following lines, I could get the https request through. As pointed out in this answer https://stackoverflow.com/a/36266735

$AllProtocols = [System.Net.SecurityProtocolType]'Ssl3,Tls,Tls11,Tls12'[System.Net.ServicePointManager]::SecurityProtocol = $AllProtocols

My full solution with Lee's code.

add-type @"using System.Net;using System.Security.Cryptography.X509Certificates;public class TrustAllCertsPolicy : ICertificatePolicy {    public bool CheckValidationResult(        ServicePoint srvPoint, X509Certificate certificate,        WebRequest request, int certificateProblem) {        return true;    }}"@$AllProtocols = [System.Net.SecurityProtocolType]'Ssl3,Tls,Tls11,Tls12'[System.Net.ServicePointManager]::SecurityProtocol = $AllProtocols[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy

An alternative implementation in pure powershell (without Add-Type of c# source):

#requires -Version 5#requires -PSEdition Desktopclass TrustAllCertsPolicy : System.Net.ICertificatePolicy {    [bool] CheckValidationResult([System.Net.ServicePoint] $a,                                 [System.Security.Cryptography.X509Certificates.X509Certificate] $b,                                 [System.Net.WebRequest] $c,                                 [int] $d) {        return $true    }}[System.Net.ServicePointManager]::CertificatePolicy = [TrustAllCertsPolicy]::new()