Get Keystore SHA1 from a keystore file programmatically in Java

KeyStore.java

package tk.pavi2410;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.cert.Certificate;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateException;

/**
 * @author [email protected] (Pavitra)
 */
public class KeyStore {

    /**
     * Gets the keystore SHA1
     *
     * @return the keystore SHA1
     */
    public String getKeystoreSha1(InputStream keystoreFile) {
        KeyStore ks = KeyStore.getInstance("PKCS12");
        ks.load(keystoreFile, "android".toCharArray()); // storepass

        // Get the chain
        Certificate[] chain = ks.getCertificateChain("androidkey"); // alias

        // Print the digest of the user cert only
        byte[] encCertInfo = chain[0].getEncoded();
        MessageDigest md = MessageDigest.getInstance("SHA1");

        byte[] digest = md.digest(encCertInfo);
        return toHexString(digest);
    }

    private String toHexString(byte[] block) {
        StringBuffer buf = new StringBuffer();
        int len = block.length;
        for (int i = 0; i < len; i++) {
            byte2hex(block[i], buf);
            if (i < len - 1) {
                buf.append(":");
            }
        }
        return buf.toString();
    }

    private void byte2hex(byte b, StringBuffer buf) {
        char[] hexChars = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
        int high = ((b & 0xf0) >> 4);
        int low = (b & 0x0f);
        buf.append(hexChars[high]);
        buf.append(hexChars[low]);
    }
}