(PowerShell) RSA Signature/Verify with .key and .cer

See more RSA Examples

Note: This example requires Chilkat v11.0.0 or greater.

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

$success = $false

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

$privKey = New-Object Chilkat.PrivateKey

# Load the private key from an RSA .key file:
$success = $privKey.LoadPemFile("privateKey.key")
if ($success -eq $false) {
    $($privKey.LastErrorText)
    exit
}

$rsa = New-Object Chilkat.Rsa

# Import the private key into the RSA component:
$success = $rsa.UsePrivateKey($privKey)
if ($success -eq $false) {
    $($rsa.LastErrorText)
    exit
}

# Create the signature as a hex string:
$rsa.EncodingMode = "hex"

$strData = "This is the string to be signed."

# Sign the string using the sha256 hash algorithm.
# Other valid choices are "md2", "sha1", "sha384",
# "sha512", and "md5".
$hexSig = $rsa.SignStringENC($strData,"sha256")

$($hexSig)

# Load a digital certificate from a .cer file:
$cert = New-Object Chilkat.Cert

$success = $cert.LoadFromFile("myCert.cer")
if ($success -eq $false) {
    $($cert.LastErrorText)
    exit
}

$pubKey = New-Object Chilkat.PublicKey
$cert.GetPublicKey($pubKey)

# Now verify using a new instance of the RSA object:
$rsa2 = New-Object Chilkat.Rsa

# Import the public key into the RSA object:
$success = $rsa2.UsePublicKey($pubKey)
if ($success -eq $false) {
    $($rsa2.LastErrorText)
    exit
}

# The signature is a hex string, so make sure the EncodingMode is correct:
$rsa2.EncodingMode = "hex"

# Verify the signature:
$success = $rsa2.VerifyStringENC($strData,"sha256",$hexSig)
if ($success -eq $false) {
    $($rsa2.LastErrorText)
    exit
}

$("Success.")