Question

如何阅读.PEM文件得到私钥和公钥

Answer 1

以下命令来生成密钥对。 $openssl genrsa -out mykey.pem 2048 $openssl pkcs8 -topk8 -inform PEM -outform PEM -in mykey.pem \ -out private_key.pem -nocrypt 这个命令得到的公共密钥。 $ openssl rsa -in mykey.pem -pubout -outform DER -out public_key.der 我写了两方法读取私钥和公钥 分别。public PrivateKey getPemPrivateKey(String filename, String algorithm) throws Exception { File f = new File(filename); FileInputStream fis = new FileInputStream(f); DataInputStream dis = new DataInputStream(fis); byte[] keyBytes = new byte[(int) f.length()]; dis.readFully(keyBytes); dis.close(); String temp = new String(keyBytes); String privKeyPEM = temp.replace("-----BEGIN PRIVATE KEY-----\n", ""); privKeyPEM = privKeyPEM.replace("-----END PRIVATE KEY-----", ""); //System.out.println("Private key\n"+privKeyPEM); Base64 b64 = new Base64(); byte [] decoded = b64.decode(privKeyPEM); PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(decoded); KeyFactory kf = KeyFactory.getInstance(algorithm); return kf.generatePrivate(spec); } public PublicKey getPemPublicKey(String filename, String algorithm) throws Exception { File f = new File(filename); FileInputStream fis = new FileInputStream(f); DataInputStream dis = new DataInputStream(fis); byte[] keyBytes = new byte[(int) f.length()]; dis.readFully(keyBytes); dis.close(); String temp = new String(keyBytes); String publicKeyPEM = temp.replace("-----BEGIN PUBLIC KEY-----\n", ""); publicKeyPEM = privKeyPEM.replace("-----END PUBLIC KEY-----", ""); Base64 b64 = new Base64(); byte [] decoded = b64.decode(publicKeyPEM); X509EncodedKeySpec spec = new X509EncodedKeySpec(decoded); KeyFactory kf = KeyFactory.getInstance(algorithm); return kf.generatePublic(spec);