openssl.md

openssl.md

openssl

install

linux

• red hat, centos
  • yum install openssl
• ubuntu
  • apt-get install openssl

windows

• http://code.google.com/p/openssl-for-windows/downloads/list
• 압축해제, 경로 변경

RSA generate

generate private pem

• openssl genrsa -out private.pem 1024

generate public pem

• openssl rsa -in private.pem -out public.pem -outform PEM -pubout

TEST crypt

# encrypt
openssl rsautl -encrypt -inkey public.pem -pubin -in plainTxt.file -out cipher.ssl
# decrypt
openssl rsautl -decrypt -inkey private.pem -in cihper.ssl -out decodePlainTxt.file

JAVA rsa

java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : algid parse error, not a sequence

이런 에러가 난다면 pkcs8 방식으로 인코딩 변경 필요

• private

  • openssl rsa -in private.pem -inform pem -out private.der -outform der
  • openssl pkcs8 -topk8 -in private.der -inform der -out private.key -outform der -nocrypt

• public

  • openssl rsa -in private.pem -inform pem -out public.key -outform der -pubout

JAVA RSA Encrypt, Decrypt

import java.io.FileInputStream;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.KeyFactory;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

import org.apache.commons.io.IOUtils;

public class RSATest {

    private String projectPath = System.getProperty("user.dir");
    private String rsaPublicKeyPath = projectPath + "/pki/public.key";
    private String rsaPrivateKeyPath = projectPath + "/pki/private.key";
    private String rsaTransformation = "RSA/ECB/PKCS1Padding";
    private String rsaEncoding = "UTF-8";
    
    public static void main(String[] ar) {
        RSATest rsa = new RSATest();
        String enc = rsa.RSAEncrypt("test");
        System.out.println(enc);
        System.out.println(rsa.RSADecrypt(enc));
    }
    
    /*
     * RSA Encrypt
     */
    public String RSAEncrypt(String plainText) {
        if ( plainText == null || "".equals(plainText)) {
            return "";
        }
        
        try {
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(IOUtils.toByteArray(new FileInputStream(rsaPublicKeyPath)));
      
            Cipher cipher = Cipher.getInstance(rsaTransformation);
            cipher.init(Cipher.ENCRYPT_MODE, KeyFactory.getInstance("RSA").generatePublic(x509EncodedKeySpec));
      
            return org.apache.commons.codec.binary.Base64.encodeBase64String(cipher.doFinal(plainText.getBytes(rsaEncoding)));
        } catch ( IOException | GeneralSecurityException e ) {
            e.printStackTrace();
            return plainText;
        }
    }
    
    /*
     * RSA Decrypt
     */
    public String RSADecrypt(String cipherText) {
        if ( cipherText == null || "".equals(cipherText)) {
            return "";
        }
        
        try {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(IOUtils.toByteArray(new FileInputStream(rsaPrivateKeyPath)));
      
            Cipher cipher = Cipher.getInstance(rsaTransformation);
            cipher.init(Cipher.DECRYPT_MODE, KeyFactory.getInstance("RSA").generatePrivate(pkcs8EncodedKeySpec));
  
            return new String(cipher.doFinal(org.apache.commons.codec.binary.Base64.decodeBase64(cipherText)), rsaEncoding);
        } catch ( IOException | GeneralSecurityException e ) {
            e.printStackTrace();
            return cipherText;
        }
    }
}