(PowerShell) RSA SHA256 Signature using Private Key from Java Keystore

Signs plaintext using RSA SHA256 using a key from a Java keystore.

Duplicatest this code:

KeyStore keystore; // key repository for keys containing signature certificate
String alias; // alias for the certificate in the key repository
String password; // password for the certificate's private key
String plaintext; // text being signed


Signature signature = Signature.getInstance("SHA256withRSA");
signature.initSign((PrivateKey) keystore.getKey(alias, password.toCharArray()));
signature.update(plaintext.getBytes("UTF-8"));
byte[] rsa_text= signature.sign();

Chilkat .NET Downloads Chilkat .NET Assemblies

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

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

$jks = New-Object Chilkat.JavaKeyStore

$jksPassword = "secret"

# Load the Java keystore from a file.  The JKS file password is used
# to verify the keyed digest that is found at the very end of the keystore.
# It verifies that the keystore has not been modified.
$success = $jks.LoadFile($jksPassword,"qa_data/jks/sample_secret.jks")
if ($success -ne $true) {
    $($jks.LastErrorText)
    exit
}

# Get the private key from the JKS.
# The private key password may be different than the file password.
$privKeyPassword = "secret"
$caseSensitive = $false
$privKey = $jks.FindPrivateKey($privKeyPassword,"some.alias",$caseSensitive)
if ($jks.LastMethodSuccess -ne $true) {
    $($jks.LastErrorText)
    exit
}

# Establish the RSA object and tell it to use the private key..
$rsa = New-Object Chilkat.Rsa

$success = $rsa.ImportPrivateKeyObj($privKey)

if ($success -ne $true) {
    $($rsa.LastErrorText)
    exit
}

# Indicate we'll be signing the utf-8 byte representation of the string..
$rsa.Charset = "utf-8"

# Sign some plaintext using RSA-SHA256

$plaintext = "this is the text to be signed"
$binarySignature = $rsa.SignString($plaintext,"SHA256")
if ($rsa.LastMethodSuccess -ne $true) {
    $($rsa.LastErrorText)
    exit
}

# Alternatively, if the signature is desired in some encoded string form,
# such as base64, base64-url, hex, etc.
$rsa.EncodingMode = "base64-url"
$signatureStr = $rsa.SignStringENC($plaintext,"SHA256")
$("base64-url RSA signature: " + $signatureStr)