Xojo Plugin

RSA SHA256 Signature using Private Key from Java Keystore

See more RSA Examples

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();

Xojo Plugin

Dim success As Boolean
success = False

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

Dim jks As New Chilkat.JavaKeyStore

Dim jksPassword As String
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 = False) Then
    System.DebugLog(jks.LastErrorText)
    Return
End If

// Get the private key from the JKS.
// The private key password may be different than the file password.
Dim privKeyPassword As String
privKeyPassword = "secret"
Dim caseSensitive As Boolean
caseSensitive = False
Dim privKey As New Chilkat.PrivateKey
success = jks.PrivateKeyOf(privKeyPassword,"some.alias",caseSensitive,privKey)
If (success = False) Then
    System.DebugLog(jks.LastErrorText)
    Return
End If

// Establish the RSA object and tell it to use the private key..
Dim rsa As New Chilkat.Rsa

success = rsa.UsePrivateKey(privKey)
If (success = False) Then
    System.DebugLog(rsa.LastErrorText)
    Return
End If

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

// Sign some plaintext using RSA-SHA256
Dim binarySignature As MemoryBlock
Dim plaintext As String
plaintext = "this is the text to be signed"
binarySignature = rsa.SignString(plaintext,"SHA256")
If (rsa.LastMethodSuccess = False) Then
    System.DebugLog(rsa.LastErrorText)
    Return
End If

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