Created
June 24, 2024 17:04
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Powershell functions for asymmetric encryption and decryption of data with an arbitrary length
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Function Encrypt-DataAsymmetric { | |
[CmdletBinding()] | |
Param | |
( | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 0)] | |
[byte[]]$Data, | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 1)] | |
[byte[]]$PublicKey | |
) | |
$CNGPublicKey = [System.Security.Cryptography.CngKey]::Import($PublicKey, [System.Security.Cryptography.CngKeyBlobFormat]::GenericPublicBlob) | |
$Encryptor = [System.Security.Cryptography.RSACng]::new($CNGPublicKey) | |
$Encryptor.Encrypt($Data, [System.Security.Cryptography.RSAEncryptionPadding]::OaepSHA384) | |
} | |
Function Decrypt-DataAsymmetric { | |
[CmdletBinding()] | |
Param | |
( | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 0)] | |
[byte[]]$Data, | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 1)] | |
[byte[]]$PrivateKey | |
) | |
$CNGPrivateKey = [System.Security.Cryptography.CngKey]::Import($PrivateKey, [System.Security.Cryptography.CngKeyBlobFormat]::GenericPrivateBlob) | |
$Decryptor = [System.Security.Cryptography.RSACng]::new($CNGPrivateKey) | |
$Decryptor.Decrypt($Data, [System.Security.Cryptography.RSAEncryptionPadding]::OaepSHA384) | |
} | |
Function Encrypt-Data { | |
[CmdletBinding()] | |
Param | |
( | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 0)] | |
[byte[]]$Data, | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 1)] | |
[byte[]]$PublicKey | |
) | |
$AES = [System.Security.Cryptography.Aes]::Create() | |
$encryptor = $AES.CreateEncryptor() | |
$ciphertext = $encryptor.TransformFinalBlock($Data, 0, $Data.Length) | |
$encryptedKey = Encrypt-DataAsymmetric -Data $AES.Key -PublicKey $PublicKey | |
New-Object PSObject ` | |
| Add-Member -MemberType NoteProperty -Name EncryptedKey -Value ([Convert]::ToBase64String($encryptedKey)) -PassThru ` | |
| Add-Member -MemberType NoteProperty -Name IV -Value ([Convert]::ToBase64String($AES.IV)) -PassThru ` | |
| Add-Member -MemberType NoteProperty -Name Ciphertext -Value ([Convert]::ToBase64String($ciphertext)) -PassThru | |
} | |
Function Decrypt-Data { | |
[CmdletBinding()] | |
Param | |
( | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 0)] | |
$EncryptedPacket, | |
[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 3)] | |
[byte[]]$PrivateKey | |
) | |
$AES = [System.Security.Cryptography.Aes]::Create() | |
$AES.Key = Decrypt-DataAsymmetric -Data ([Convert]::FromBase64String($EncryptedPacket.EncryptedKey)) -PrivateKey $PrivateKey | |
$AES.IV = [Convert]::FromBase64String($EncryptedPacket.IV) | |
$decryptor = $AES.CreateDecryptor() | |
$ciphertext = [Convert]::FromBase64String($EncryptedPacket.Ciphertext) | |
$decryptor.TransformFinalBlock($ciphertext, 0, $ciphertext.Length) | |
} | |
Function New-AsymmetricKey { | |
$RSACNG = [System.Security.Cryptography.RSACng]::new(3072) | |
$key = $RSACNG.Key | |
New-Object psobject ` | |
| Add-Member -MemberType NoteProperty -Name PublicKey -Value ($key.Export([System.Security.Cryptography.CngKeyBlobFormat]::GenericPublicBlob)) -PassThru ` | |
| Add-Member -MemberType NoteProperty -Name PrivateKey -Value ($key.Export([System.Security.Cryptography.CngKeyBlobFormat]::GenericPrivateBlob)) -PassThru | |
} |
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