(PowerShell) RSA Encrypt and Decrypt Strings

PowerShell sample code to RSA public-key encrypt and decrypt strings using public and private keys.

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Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$rsa = New-Object Chilkat.Rsa

# This example also generates the public and private
# keys to be used in the RSA encryption.
# Normally, you would generate a key pair once,
# and distribute the public key to your partner.
# Anything encrypted with the public key can be
# decrypted with the private key.  The reverse is 
# also true: anything encrypted using the private
# key can be decrypted using the public key.

# Generate a 1024-bit key.  Chilkat RSA supports
# key sizes ranging from 512 bits to 4096 bits.
$success = $rsa.GenerateKey(1024)
if ($success -ne $true) {
    $($rsa.LastErrorText)
    exit
}

# Keys are exported in XML format:
$publicKey = $rsa.ExportPublicKey()
$privateKey = $rsa.ExportPrivateKey()

$plainText = "Encrypting and decrypting should be easy!"

# Start with a new RSA object to demonstrate that all we
# need are the keys previously exported:
$rsaEncryptor = New-Object Chilkat.Rsa

# Encrypted output is always binary.  In this case, we want
# to encode the encrypted bytes in a printable string.
# Our choices are "hex", "base64", "url", "quoted-printable".
$rsaEncryptor.EncodingMode = "hex"

# We'll encrypt with the public key and decrypt with the private
# key.  It's also possible to do the reverse.
$success = $rsaEncryptor.ImportPublicKey($publicKey)

$usePrivateKey = $false
$encryptedStr = $rsaEncryptor.EncryptStringENC($plainText,$usePrivateKey)
$($encryptedStr)

# Now decrypt:
$rsaDecryptor = New-Object Chilkat.Rsa

$rsaDecryptor.EncodingMode = "hex"
$success = $rsaDecryptor.ImportPrivateKey($privateKey)

$usePrivateKey = $true
$decryptedStr = $rsaDecryptor.DecryptStringENC($encryptedStr,$usePrivateKey)

$($decryptedStr)