(Java) RSA Signature using Private Key from .snk File

See more RSA Examples

A .snk file (Strong Name Key file) is a file format used in the .NET ecosystem to store an RSA public/private key pair. This key pair is typically used for strong-naming assemblies, which is a process of signing .NET assemblies to ensure their integrity and to uniquely identify them.

This example loads a private key from a .snk file and creates an RSA signature.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    CkRsa rsa = new CkRsa();

    // Load the .snk and return the private key as XML.
    String xmlStr = rsa.snkToXml("./test.snk");
    if (rsa.get_LastMethodSuccess() == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    boolean success = rsa.ImportPrivateKey(xmlStr);
    if (success == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    // Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
    // Return the signature in base64 format.
    rsa.put_EncodingMode("base64");
    rsa.put_Charset("utf-8");
    String sigBase64 = rsa.signStringENC("This is the text to be hashed and signed.","sha256");
    if (rsa.get_LastMethodSuccess() == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    System.out.println("RSA signature as base64: " + sigBase64);
  }
}