Adds tool function for easily creating basic auth headers

lib/core/tools/New-IcingaBasicAuthHeader.psm1

@@ -0,0 +1,53 @@
+<#
+.SYNOPSIS
+   Creates a basic auth header for web requests in case the Get-Credential
+   method is not supported or working properly
+.DESCRIPTION
+   Creates a basic auth header for web requests in case the Get-Credential
+   method is not supported or working properly
+.FUNCTIONALITY
+   Creates a hashtable with a basic authorization header as Base64 encoded
+.EXAMPLE
+   PS>New-IcingaBasicAuthHeader -Username 'example_user' -Password $SecurePasswordString;
+.EXAMPLE
+   PS>New-IcingaBasicAuthHeader -Username 'example_user' -Password (Read-Host -Prompt 'Please enter your password' -AsSecureString);
+.EXAMPLE
+   PS>New-IcingaBasicAuthHeader -Username 'example_user' -Password (ConvertTo-IcingaSecureString 'my_secret_password');
+.PARAMETER Username
+   The user we will use to authenticate for
+.PARAMETER Password
+   The password for the user provided as SecureString
+.INPUTS
+   System.String
+.OUTPUTS
+   System.Hashtable
+.LINK
+   https://github.com/Icinga/icinga-powershell-framework
+#>
+
+function New-IcingaBasicAuthHeader()
+{
+    param(
+        [string]$Username       = $null,
+        [SecureString]$Password = $null
+    );
+
+    if ($null -eq $Password -or [string]::IsNullOrEmpty($Username)) {
+        Write-Host 'Please specify your Username and Password to continue';
+        return @{};
+    }
+
+    $Credentials = [System.Convert]::ToBase64String(
+        [System.Text.Encoding]::ASCII.GetBytes(
+            [string]::Format(
+                '{0}:{1}',
+                $Username,
+                (ConvertFrom-IcingaSecureString $Password)
+            )
+        )
+    );
+
+    return @{
+        'Authorization' = [string]::Format('Basic {0}', $Credentials)
+    };
+}