k.e.book.common.utils.RSAEncryptor Maven / Gradle / Ivy

Go to download
package k.e.book.common.utils;

import org.springframework.util.Base64Utils;
import org.springframework.util.StringUtils;

import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.X509EncodedKeySpec;
import java.util.Objects;

public class RSAEncryptor {
    public static final String RSA_ALGORITHM = "RSA";
    /**
     * 签名算法
     */
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    /**
     * 验签
     *
     * @param content
     * @param charset
     * @param publicKey
     * @param sign
     * @return
     * @throws Exception
     */
    public static boolean doVerify(String content, String charset, String publicKey, String sign) {
        try {
            PublicKey pubKey = getPublicKey(publicKey);
            Signature signature = Signature.getInstance(SIGN_ALGORITHMS);
            signature.initVerify(pubKey);
            if (StringUtils.isEmpty(charset)) {
                signature.update(content.getBytes());
            } else {
                signature.update(content.getBytes(charset));
            }
            return signature.verify(Base64Utils.decodeFromString(sign));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 得到公钥
     *
     * @param base64PubKey 密钥字符串（经过base64编码）
     * @return PublicKey
     */
    public static PublicKey getPublicKey(String base64PubKey) throws Exception {
        Objects.requireNonNull(base64PubKey, "base64 public key is null.");
        byte[] keyBytes = Base64Utils.decodeFromString(base64PubKey);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_ALGORITHM);
        return keyFactory.generatePublic(keySpec);
    }
}