Improved efficiency when working with large files

Author: alan-null

Crypto.AES/Public/Protect-Data.ps1

@@ -30,14 +30,21 @@ function Protect-Data {
         }
 
         $gcm.Encrypt($Nonce, $Data, $cipherOutput, $tag)
+        $gcm.Dispose()
 
         if ($Combined) {
-            return $tag + $cipherOutput + $Nonce
+            $output = [byte[]]::new($cipherOutput.Length + $Nonce.Length + $tag.Length)
+            [System.Buffer]::BlockCopy($tag, 0, $output, 0, $tag.Length);
+            [System.Buffer]::BlockCopy($cipherOutput, 0, $output, $tag.Length, $cipherOutput.Length);
+            [System.Buffer]::BlockCopy($Nonce, 0, $output, $tag.Length + $cipherOutput.Length, $Nonce.Length);
+            Write-Output $output -NoEnumerate
         }
-        @{
-            CipherText = $cipherOutput
-            Nonce      = $Nonce
-            Tag        = $tag
+        else {
+            @{
+                CipherText = $cipherOutput
+                Nonce      = $Nonce
+                Tag        = $tag
+            }
         }
     }
 

Crypto.AES/Public/Unprotect-Data.ps1

@@ -25,7 +25,7 @@ function Unprotect-Data {
             $gcm = [System.Security.Cryptography.AesGcm]::new($Key)
         }
         $gcm.Decrypt($nonce, $Data, $Tag, $decrypted)
-        $decrypted
+        Write-Output $decrypted -NoEnumerate
     }
 
     end {

Tests/Crypto.AES.Tests.ps1

@@ -46,7 +46,7 @@ Describe 'Crypto.AES.Tests' {
             $r.CipherText | Should -BeNullOrEmpty
             $r.Nonce | Should -BeNullOrEmpty
             $r.Tag | Should -BeNullOrEmpty
-            $r -is [System.Object[]] | Should -BeTrue
+            $r -is [byte[]] | Should -BeTrue
             $r.Length | Should -BeExactly ($data.Length + $nonce.Length + 16)
         }
     }