RSA私钥仅支持RSAPrivate（Crt）KeySpec和PKCS8EncodedKeySpec
我按照链接中的步骤操作： 如何读取.pem文件以获取私钥和公钥 。 我执行了以下三个命令：
1. $openssl genrsa -out mykey.pem 2048 2. $openssl pkcs8 -topk8 -inform PEM -outform PEM -in mykey.pem -out private_key.pem -nocrypt 3. $ openssl rsa -in mykey.pem -pubout -outform DER -out public_key.der 这创建了三个文件，但是当我尝试通过Java代码读取这些文件时，我开始面临以下错误：
PUBLIC KEY EXPO : 65537 Only RSAPrivate(Crt)KeySpec and PKCS8EncodedKeySpec supported for RSA private keys
我的代码供参考：
public class PublicPrivateKeyDemo { private static File privateKeyFile = null; private static File publicKeyFile = null; public static void main(String[] args) { String path = "C:/Users/test898/keys"; privateKeyFile = new File(path + "/" + "private.pem"); publicKeyFile = new File(path + "/" + "public.der"); try { loadkeys(); } catch (IOException | GeneralSecurityException e) { System.out.println(e.getMessage()); } } private static void loadkeys() throws IOException, GeneralSecurityException { byte[] publicKeyBytes = new byte[(int) publicKeyFile.length()]; FileInputStream publicFis = null; publicFis = new FileInputStream(publicKeyFile); if (publicFis.read(publicKeyBytes) > 0) { X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(publicKeyBytes); KeyFactory factory = KeyFactory.getInstance("RSA"); RSAPublicKey pubKey = (RSAPublicKey) factory.generatePublic(publicKeySpec); BigInteger pKeyModulus = pubKey.getModulus(); BigInteger pKeyExponent = pubKey.getPublicExponent(); System.out.println("PUBLIC KEY EXPO : "+pKeyExponent); } byte[] privateKeyBytes = new byte[(int) privateKeyFile.length()]; FileInputStream privateFis = null; privateFis = new FileInputStream(privateKeyFile); if (privateFis.read(privateKeyBytes) > 0) { //PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(privateKeyBytes); X509EncodedKeySpec spec = new X509EncodedKeySpec(privateKeyBytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); RSAPrivateKey privKey = (RSAPrivateKey) keyFactory.generatePrivate(spec); BigInteger pKeyModulus = privKey.getModulus(); BigInteger pKeyExponent = privKey.getPrivateExponent(); System.out.println("PRIVATE KEY : "+pKeyExponent); } } }
请帮帮我这里错了吗？ 我假设私钥应该给出类似下面的值：“：
21150549370950609585296765828149303178265715265804890679831411170495636016527926323370428466362501818569080118374307191403222367256185274427528812911191842330928112748042350818573390540259857225467392220170770506599589136056049534085562156615813126185240565396115577449461468695709719589257257375788267753694280485882595576829517086782992300102288858453543505912425724874212273830247789870669315715724390578125469483751830964757980799543436412647956770560679365767737577100276745456138533646455249170660612983618544127693626739283128573829732806886889896396374650462743743148634276240986662548043510018342217214342529
根据链接： http ： //codeartisan.blogspot.in/2009/05/public-key-cryptography-in-java.html你应该尝试以下
生成2048位RSA私钥
$ openssl genrsa -out private_key.pem 2048
将私钥转换为PKCS＃8格式（因此Java可以读取它）
$ openssl pkcs8 -topk8 -inform PEM -outform DER -in private_key.pem -out private_key.der -nocrypt
以DER格式输出公钥部分（因此Java可以读取它）
$ openssl rsa -in private_key.pem -pubout -outform DER -out public_key.der
你可以阅读如下的java代码：
import java.io.DataInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.security.KeyFactory; import java.security.NoSuchAlgorithmException; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.InvalidKeySpecException; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; public class Demo { public static final String PRIVATE_KEY="/home/user/private.der"; public static final String PUBLIC_KEY="/home/user/public.der"; public static void main(String[] args) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException { //get the private key File file = new File(PRIVATE_KEY); FileInputStream fis = new FileInputStream(file); DataInputStream dis = new DataInputStream(fis); byte[] keyBytes = new byte[(int) file.length()]; dis.readFully(keyBytes); dis.close(); PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory kf = KeyFactory.getInstance("RSA"); RSAPrivateKey privKey = (RSAPrivateKey) kf.generatePrivate(spec); System.out.println("Exponent :" + privKey.getPrivateExponent()); System.out.println("Modulus" + privKey.getModulus()); //get the public key File file1 = new File(PUBLIC_KEY); FileInputStream fis1 = new FileInputStream(file1); DataInputStream dis1 = new DataInputStream(fis1); byte[] keyBytes1 = new byte[(int) file1.length()]; dis1.readFully(keyBytes1); dis1.close(); X509EncodedKeySpec spec1 = new X509EncodedKeySpec(keyBytes1); KeyFactory kf1 = KeyFactory.getInstance("RSA"); RSAPublicKey pubKey = (RSAPublicKey) kf1.generatePublic(spec1); System.out.println("Exponent :" + pubKey.getPublicExponent()); System.out.println("Modulus" + pubKey.getModulus()); } }
节目输出：
PUBLIC KEY EXPO : 65537 PRIVATE KEY :