网站内容营销,注册网址免费,高端响应式网站建设,wordpress 4.8上传漏洞文章目录 一、签名验签原理二 RSAUtils 工具类三、通过x509Certificate来获取CA证书的基本信息四、 通过公钥获取公钥长度 一、签名验签原理
签名的本质其实就是加密#xff0c;但是由于签名无需还原成明文#xff0c;因此可以在加密前进行哈希处理。所以签名其实就是哈希加… 文章目录 一、签名验签原理二 RSAUtils 工具类三、通过x509Certificate来获取CA证书的基本信息四、 通过公钥获取公钥长度 一、签名验签原理
签名的本质其实就是加密但是由于签名无需还原成明文因此可以在加密前进行哈希处理。所以签名其实就是哈希加密而验签就是哈希解密比较。
签名过程对明文做哈希拼接头信息用私钥进行加密得到签名。
验签过程用公钥解密签名然后去除头信息对明文做哈希比较2段哈希值是否相同相同则验签成功。 代码编写 Cipher 用于加密 Signature 用于签名
二 RSAUtils 工具类
package com.example.tr34.application.utils;import android.util.Base64;import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;import javax.crypto.Cipher;/*** date:2020/9/4 0004* author:wsm (Administrator)* funcation: 私钥有问题base64解码失败*/public class RSAUtils {private static String RSA RSA;/*** *** RSA最大加密大小*/private final static int MAX_ENCRYPT_BLOCK 117;/*** *** RSA最大解密大小*/private final static int MAX_DECRYPT_BLOCK 128;/*** 随机生成RSA密钥对(默认密钥长度为1024)** return*/public static KeyPair generateRSAKeyPair() {return generateRSAKeyPair(1024);}/*** 随机生成RSA密钥对** param keyLength 密钥长度范围5122048br* 一般1024* return*/public static KeyPair generateRSAKeyPair(int keyLength) {try {KeyPairGenerator kpg KeyPairGenerator.getInstance(RSA);kpg.initialize(keyLength);return kpg.genKeyPair();} catch (NoSuchAlgorithmException e) {e.printStackTrace();return null;}}/*** 用公钥加密 br* 每次加密的字节数不能超过密钥的长度值减去11** param data 需加密数据的byte数据* param publicKey 公钥* return 加密后的byte型数据*/public static byte[] encryptData(byte[] data, PublicKey publicKey) {try {Cipher cipher Cipher.getInstance(RSA/ECB/PKCS1Padding);// 编码前设定编码方式及密钥cipher.init(Cipher.ENCRYPT_MODE, publicKey);// 传入编码数据并返回编码结果return cipher.doFinal(data);} catch (Exception e) {e.printStackTrace();return null;}}/*** 用私钥解密** param encryptedData 经过encryptedData()加密返回的byte数据* param privateKey 私钥* return*/public static byte[] decryptData(byte[] encryptedData, PrivateKey privateKey) {try {Cipher cipher Cipher.getInstance(RSA/ECB/PKCS1Padding);cipher.init(Cipher.DECRYPT_MODE, privateKey);return cipher.doFinal(encryptedData);} catch (Exception e) {return null;}}/*** 通过公钥byte[](publicKey.getEncoded())将公钥还原适用于RSA算法** param keyBytes* return* throws NoSuchAlgorithmException* throws InvalidKeySpecException*/public static PublicKey getPublicKey(byte[] keyBytes) throws NoSuchAlgorithmException,InvalidKeySpecException {X509EncodedKeySpec keySpec new X509EncodedKeySpec(keyBytes);KeyFactory keyFactory KeyFactory.getInstance(RSA);PublicKey publicKey keyFactory.generatePublic(keySpec);return publicKey;}/*** 通过私钥byte[]将公钥还原适用于RSA算法** param keyBytes* return* throws NoSuchAlgorithmException* throws InvalidKeySpecException*/public static PrivateKey getPrivateKey(byte[] keyBytes) throws NoSuchAlgorithmException,InvalidKeySpecException {PKCS8EncodedKeySpec keySpec new PKCS8EncodedKeySpec(keyBytes);KeyFactory keyFactory KeyFactory.getInstance(RSA);PrivateKey privateKey keyFactory.generatePrivate(keySpec);return privateKey;}/*** 使用N、e值还原公钥** param modulus* param publicExponent* return* throws NoSuchAlgorithmException* throws InvalidKeySpecException*/public static PublicKey getPublicKey(String modulus, String publicExponent)throws NoSuchAlgorithmException, InvalidKeySpecException {BigInteger bigIntModulus new BigInteger(modulus);BigInteger bigIntPrivateExponent new BigInteger(publicExponent);RSAPublicKeySpec keySpec new RSAPublicKeySpec(bigIntModulus, bigIntPrivateExponent);KeyFactory keyFactory KeyFactory.getInstance(RSA);PublicKey publicKey keyFactory.generatePublic(keySpec);return publicKey;}/*** 使用N、d值还原私钥** param modulus* param privateExponent* return* throws NoSuchAlgorithmException* throws InvalidKeySpecException*/public static PrivateKey getPrivateKey(String modulus, String privateExponent)throws NoSuchAlgorithmException, InvalidKeySpecException {BigInteger bigIntModulus new BigInteger(modulus);BigInteger bigIntPrivateExponent new BigInteger(privateExponent);RSAPublicKeySpec keySpec new RSAPublicKeySpec(bigIntModulus, bigIntPrivateExponent);KeyFactory keyFactory KeyFactory.getInstance(RSA);PrivateKey privateKey keyFactory.generatePrivate(keySpec);return privateKey;}/*** 从字符串中加载公钥** param publicKeyStr 公钥数据字符串* throws Exception 加载公钥时产生的异常*/public static PublicKey loadPublicKey(String publicKeyStr) throws Exception {try {byte[] buffer Base64.decode(publicKeyStr,Base64.DEFAULT);KeyFactory keyFactory KeyFactory.getInstance(RSA);X509EncodedKeySpec keySpec new X509EncodedKeySpec(buffer);return (RSAPublicKey) keyFactory.generatePublic(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception(无此算法);} catch (InvalidKeySpecException e) {throw new Exception(公钥非法);} catch (NullPointerException e) {throw new Exception(公钥数据为空);}}/*** 从字符串中加载私钥br* 加载时使用的是PKCS8EncodedKeySpecPKCS#8编码的Key指令。** param privateKeyStr* return* throws Exception*/public static PrivateKey loadPrivateKey(String privateKeyStr) throws Exception {try {byte[] buffer Base64.decode(privateKeyStr,Base64.DEFAULT);// X509EncodedKeySpec keySpec new X509EncodedKeySpec(buffer);PKCS8EncodedKeySpec keySpec new PKCS8EncodedKeySpec(buffer);KeyFactory keyFactory KeyFactory.getInstance(RSA);return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception(无此算法);} catch (InvalidKeySpecException e) {throw new Exception(私钥非法);} catch (NullPointerException e) {throw new Exception(私钥数据为空);}}/*** 用公钥分段加密 br* 每次加密的字节数不能超过密钥的长度值减去11** param data 需加密数据的byte数据* param publicKey 公钥* return 加密后的byte型数据*/public static byte[] PublicSubData(byte[] data, PublicKey publicKey) {try {Cipher cipher Cipher.getInstance(RSA/ECB/PKCS1Padding);// 编码前设定编码方式及密钥cipher.init(Cipher.ENCRYPT_MODE, publicKey);// 传入编码数据并返回编码结果
// return cipher.doFinal(data);int inputLen data.length;ByteArrayOutputStream out new ByteArrayOutputStream();int offSet 0;byte[] cache;int i 0;// 对数据分段加密while (inputLen - offSet 0){if (inputLen - offSet MAX_ENCRYPT_BLOCK){cache cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);} else{cache cipher.doFinal(data, offSet, inputLen - offSet);}out.write(cache, 0, cache.length);i;offSet i * MAX_ENCRYPT_BLOCK;}byte[] decryptedData out.toByteArray();out.close();return decryptedData;} catch (Exception e) {e.printStackTrace();return null;}}/*** 用私钥分段解密** param encryptedData 经过encryptedData()加密返回的byte数据* param privateKey 私钥* return*/public static byte[] PrivateSubData(byte[] encryptedData, PrivateKey privateKey) {try {Cipher cipher Cipher.getInstance(RSA/ECB/PKCS1Padding);cipher.init(Cipher.DECRYPT_MODE, privateKey);
// return cipher.doFinal(encryptedData);// 返回UTF-8编码的解密信息int inputLen encryptedData.length;ByteArrayOutputStream out new ByteArrayOutputStream();int offSet 0;byte[] cache;int i 0;// 对数据分段解密while (inputLen - offSet 0){if (inputLen - offSet MAX_DECRYPT_BLOCK){cache cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);} else{cache cipher.doFinal(encryptedData, offSet, inputLen - offSet);}out.write(cache, 0, cache.length);i;offSet i * MAX_DECRYPT_BLOCK;}byte[] decryptedData out.toByteArray();out.close();return decryptedData;} catch (Exception e) {return null;}}/*** 从文件中输入流中加载公钥** param in 公钥输入流* throws Exception 加载公钥时产生的异常*/public static PublicKey loadPublicKey(InputStream in) throws Exception {try {return loadPublicKey(readKey(in));} catch (IOException e) {throw new Exception(公钥数据流读取错误);} catch (NullPointerException e) {throw new Exception(公钥输入流为空);}}/*** 从文件中加载私钥** param in 私钥文件名* return 是否成功* throws Exception*/public static PrivateKey loadPrivateKey(InputStream in) throws Exception {try {return loadPrivateKey(readKey(in));} catch (IOException e) {throw new Exception(私钥数据读取错误);} catch (NullPointerException e) {throw new Exception(私钥输入流为空);}}/*** 读取密钥信息** param in* return* throws IOException*/private static String readKey(InputStream in) throws IOException {BufferedReader br new BufferedReader(new InputStreamReader(in));String readLine null;StringBuilder sb new StringBuilder();while ((readLine br.readLine()) ! null) {if (readLine.charAt(0) -) {continue;} else {sb.append(readLine);sb.append(\r);}}return sb.toString();}/*** 打印公钥信息** param publicKey*/public static void printPublicKeyInfo(PublicKey publicKey) {RSAPublicKey rsaPublicKey (RSAPublicKey) publicKey;System.out.println(----------RSAPublicKey----------);System.out.println(Modulus.length rsaPublicKey.getModulus().bitLength());System.out.println(Modulus rsaPublicKey.getModulus().toString());System.out.println(PublicExponent.length rsaPublicKey.getPublicExponent().bitLength());System.out.println(PublicExponent rsaPublicKey.getPublicExponent().toString());}public static void printPrivateKeyInfo(PrivateKey privateKey) {RSAPrivateKey rsaPrivateKey (RSAPrivateKey) privateKey;System.out.println(----------RSAPrivateKey ----------);System.out.println(Modulus.length rsaPrivateKey.getModulus().bitLength());System.out.println(Modulus rsaPrivateKey.getModulus().toString());System.out.println(PrivateExponent.length rsaPrivateKey.getPrivateExponent().bitLength());System.out.println(PrivatecExponent rsaPrivateKey.getPrivateExponent().toString());}
}
三、通过x509Certificate来获取CA证书的基本信息 //创建X509工厂类CertificateFactory cf CertificateFactory.getInstance(X.509);//创建证书对象X509Certificate oCert (X509Certificate)cf.generateCertificate(inStream);// inStream证书的传入数据inStream.close();SimpleDateFormat dateformat new SimpleDateFormat(yyyy/MM/dd);String info null;//获得证书版本info String.valueOf(oCert.getVersion());System.out.println(证书版本:info);//获得证书序列号info oCert.getSerialNumber().toString(16);System.out.println(证书序列号:info);//获得证书有效期Date beforedate oCert.getNotBefore();info dateformat.format(beforedate);System.out.println(证书生效日期:info);Date afterdate oCert.getNotAfter();info dateformat.format(afterdate);System.out.println(证书失效日期:info);//获得证书主体信息info oCert.getSubjectDN().getName();System.out.println(证书拥有者:info);//获得证书颁发者信息info oCert.getIssuerDN().getName();System.out.println(证书颁发者:info);//获得证书签名算法名称info oCert.getSigAlgName();System.out.println(证书签名算法:info);byte[] byt oCert.getExtensionValue(1.2.86.11.7.9);String strExt new String(byt);System.out.println(证书扩展域: strExt);byt oCert.getExtensionValue(1.2.86.11.7.1.8);String strExt2 new String(byt);System.out.println(证书扩展域2: strExt2);四、 通过公钥获取公钥长度
通过X509Certificate.getPublicKey 获取公钥 /*** Gets the key length of supported keys* param pk PublicKey used to derive the keysize* return -1 if key is unsupported, otherwise a number 0. 0 usually means the length can not be calculated,* for example if the key is an EC key and the implicitlyCA encoding is used.*/public static int getKeyLength(final PublicKey pk) {int len -1;if (pk instanceof RSAPublicKey) {final RSAPublicKey rsapub (RSAPublicKey) pk;len rsapub.getModulus().bitLength();} else if (pk instanceof JCEECPublicKey) {final JCEECPublicKey ecpriv (JCEECPublicKey) pk;final org.bouncycastle.jce.spec.ECParameterSpec spec ecpriv.getParameters();if (spec ! null) {len spec.getN().bitLength();} else {// We support the key, but we dont know the key lengthlen 0;}} else if (pk instanceof ECPublicKey) {final ECPublicKey ecpriv (ECPublicKey) pk;final java.security.spec.ECParameterSpec spec ecpriv.getParams();if (spec ! null) {len spec.getOrder().bitLength(); // does this really return something we expect?} else {// We support the key, but we dont know the key lengthlen 0;}} else if (pk instanceof DSAPublicKey) {final DSAPublicKey dsapub (DSAPublicKey) pk;if ( dsapub.getParams() ! null ) {len dsapub.getParams().getP().bitLength();} else {len dsapub.getY().bitLength();}}return len;}
