(PowerShell) Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

Chilkat .NET Downloads Chilkat .NET Assemblies

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

# Generate a 2048-bit RSA key.
$success = $rsa.GenerateKey(2048)

# To return the signature in hex.
$rsa.EncodingMode = "hex"

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

# Sign the SHA256 hash of the string.
$hexSig = $rsa.SignStringENC($strData,"sha256")

$($hexSig)
$($rsa.LastErrorText)

# Now verify the signature:
$success = $rsa.VerifyStringENC($strData,"sha256",$hexSig)
if ($success -eq $true) {
    $("Signature verified!")
}
else {
    $($rsa.LastErrorText)
}

# Try it with an invalid signature:
$success = $rsa.VerifyStringENC($strData,"sha256","not a valid sig")
if ($success -eq $true) {
    $("Signature verified!")
}
else {
    $($rsa.LastErrorText)
}

# Try it with invalid data:
$success = $rsa.VerifyStringENC("Not the original data","sha256",$hexSig)
if ($success -eq $true) {
    $("Signature verified!")
}
else {
    $($rsa.LastErrorText)
}

# Try it with the wrong hash algorithm:
$success = $rsa.VerifyStringENC($strData,"sha-1",$hexSig)
if ($success -eq $true) {
    $("Signature verified!")
}
else {
    $($rsa.LastErrorText)
}