rsa Verify Hex String - Android java.security

Android examples for java.security:RSA

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Description

rsa Verify Hex String

Demo Code


import java.security.KeyFactory;
import java.security.MessageDigest;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Locale;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;

public class Main{
    /* w  w  w  . ja  v  a 2s. c  om*/
    public static final String HEX_DIGITS = "0123456789ABCDEF";
    /**
     * UTF-8
     */
    public static final String UTF_8 = "UTF-8";
    /**
     * rsaVerifyHex
     * @param content
     * @param sign
     * @param publicKey
     * @return
     * @throws Exception
     */
    public static boolean rsaVerifyHex(String content, String sign,
            String publicKey) throws Exception {
        if (StringUtils.isBlank(content) || StringUtils.isBlank(sign)
                || StringUtils.isBlank(publicKey)) {
            throw new Exception("illegal params.");
        }
        return rsaVerify(content.getBytes(UTF_8), hexStringToBytes(sign),
                publicKey.getBytes(UTF_8));
    }
    /**
     * rsaVerify
     * @param content
     * @param sign
     * @param publicKey
     * @return
     * @throws Exception
     */
    public static boolean rsaVerify(byte[] content, byte[] sign,
            byte[] publicKey) throws Exception {
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] encodedKey = Base64.decode(publicKey, Base64.DEFAULT);
        PublicKey publicKeyObj = keyFactory
                .generatePublic(new X509EncodedKeySpec(encodedKey));
        java.security.Signature signature = java.security.Signature
                .getInstance("SHA1WithRSA");
        signature.initVerify(publicKeyObj);
        signature.update(content);
        return signature.verify(sign);
    }
    
    public static byte[] hexStringToBytes(String hexString) {
        if (StringUtils.isBlank(hexString)) {
            return null;
        }
        char[] hexChars = hexString.toUpperCase(Locale.US).toCharArray();
        int length = hexString.length() / 2;
        byte[] bytes = new byte[length];
        for (int i = 0; i < length; ++i) {
            bytes[i] = (byte) (HEX_DIGITS.indexOf(hexChars[i * 2]) << 4 | HEX_DIGITS
                    .indexOf(hexChars[i * 2 + 1]));
        }
        return bytes;
    }
}

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