(PowerShell) RSA Sign Binary Data and Verify (Recover the Original Data)

Demonstrates how to RSA sign binary data and then verify/recover the original data.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

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

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

# Load an RSA private key for signing.
$privKey = New-Object Chilkat.PrivateKey
$success = $privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
if ($success -ne $true) {
    $($privKey.LastErrorText)
    exit
}

$rsa = New-Object Chilkat.Rsa
$rsa.ImportPrivateKeyObj($privKey)

# We have some binary data (in hex) to sign
$originalData = "0102030405060708090A"
$bd = New-Object Chilkat.BinData
$bd.AppendEncoded($originalData,"hex")

# If successful, the contents of bd are replaced with the RSA signature.
$success = $rsa.OpenSslSignBd($bd)
if ($success -ne $true) {
    $($rsa.LastErrorText)
    exit
}

# Show the RSA signature in base64
$($bd.GetEncoded("base64"))

# ------------------------------------------
# Get the public key from the private key
$pubKey = $privKey.GetPublicKey()

# Verify the signature and extract the original data.
$rsa2 = New-Object Chilkat.Rsa
$rsa2.ImportPublicKeyObj($pubKey)

$bVerified = $rsa2.OpenSslVerifyBd($bd)
$("signature verified: " + $bVerified)

# Show the original data:
$("original data: " + $bd.GetEncoded("hex"))