Java

RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

See more Apple Keychain Examples

Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Rsa;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
        // this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

        // Chilkat automatically detects and determines the way in which the HSM is used,
        // which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

        Cert cert = new Cert();

        // Set the token/smartcard PIN prior to loading.
        cert.setSmartCardPin("123456");

        // Specify the certificate by its common name.
        try {
            cert.loadFromSmartcard("cn=chilkat-rsa-2048");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Signing with cert: " + cert.getSubjectCN());

        // Create a string to be hashed and signed.
        StringBuilder sb = new StringBuilder();
        boolean crlfLineEnding = true;
        for (int i = 0; i <= 10; i++) {
            sb.appendLine("This is a test.", crlfLineEnding);
        }

        Rsa rsa = new Rsa();

        // Use the certificate's private key for signing.
        try {
            rsa.setX509Cert(cert, true);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
        // Return the signature in base64 format.
        rsa.setEncodingMode("base64");
        rsa.setCharset("utf-8");
        String stringToSign = sb.getAsString();
        String sigBase64;
        try {
            sigBase64 = rsa.signStringENC(stringToSign, "sha256");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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