I'm developing an application that will store ECC public keys in a database. I used a existing code to generate the keys, but when I use the method to get the public key from a private key, I get two values (x and y coordinates) returned. Is there a java-ready function that allows me to generate a public key from these two values? I found a link explaining how to do it, but I did not understand how to use the method.
package test;
import java.sql.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.security.*;
import java.security.spec.*;
public class test {
public static void main(String[] args) {
KeyPairGenerator kpg;
kpg = KeyPairGenerator.getInstance("EC","SunEC");
ECGenParameterSpec ecsp;
ecsp = new ECGenParameterSpec("secp256r1");
kpg.initialize(ecsp);
String key;
KeyPair kp = kpg.genKeyPair();
PrivateKey privKey = kp.getPrivate();
PublicKey pubKey = kp.getPublic();
key = pubKey.toString().substring(46,125).concat(pubKey.toString().substring(142,220));
}
}
Related
I have generated an ECDSA signature in Java and I would like to get the R and S values from it. It is my understanding that the signature I have generated is DER encoded. Can someone please provide me with some Java code (maybe using Bouncy Castle) to retrieve the R and S values as BigIntegers?
Note: In case it helps, I generated the signature using a built in provider via the JCE's Signature class and the signature lengths for my P_256 EC key pair hover between 70 and 72 bytes usually.
I was able to solve this myself. In case it helps anyone here is how I did it (most exception handling has been stripped for readability):
import java.io.ByteArrayInputStream;
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Security;
import java.security.Signature;
import java.security.spec.ECGenParameterSpec;
import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class DecodeEcdsaSignature {
public static void main(String[] args) throws Exception {
Security.addProvider(new BouncyCastleProvider());
byte[] signature = getSignature();
ASN1Primitive asn1 = toAsn1Primitive(signature);
if (asn1 instanceof ASN1Sequence) {
ASN1Sequence asn1Sequence = (ASN1Sequence) asn1;
ASN1Encodable[] asn1Encodables = asn1Sequence.toArray();
for (ASN1Encodable asn1Encodable : asn1Encodables) {
ASN1Primitive asn1Primitive = asn1Encodable.toASN1Primitive();
if (asn1Primitive instanceof ASN1Integer) {
ASN1Integer asn1Integer = (ASN1Integer) asn1Primitive;
BigInteger integer = asn1Integer.getValue();
System.out.println(integer.toString());
}
}
}
}
private static ASN1Primitive toAsn1Primitive(byte[] data) throws Exception
{
try (ByteArrayInputStream inStream = new ByteArrayInputStream(data);
ASN1InputStream asnInputStream = new ASN1InputStream(inStream);)
{
return asnInputStream.readObject();
}
}
private static byte[] getSignature() throws Exception {
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("ECDSA");
ECGenParameterSpec ecParameterSpec = new ECGenParameterSpec("P-256");
keyPairGenerator.initialize(ecParameterSpec);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
Signature signature = Signature.getInstance("SHA256withECDSA");
signature.initSign(keyPair.getPrivate());
signature.update("message to sign".getBytes("UTF-8"));
return signature.sign();
}
}
I am totally new to security and signature verification and so far I couldn't find a place which explained the basics of signature verification. I need to verify the signature of a file by obtaining the public key from the appropriate certificate available from certificate store. the tutorial in Java (https://docs.oracle.com/javase/tutorial/security/apisign/versig.html) doesn't teach how to obtain a certificate from the trusted certificate store and verify using that. I went through Bouncy castle WIKI http://www.bouncycastle.org/wiki/display/JA1/BC+Version+2+APIs but its not really explanatory for a beginner. How do I do this? Given a signed file, how can I check for its public key from the certificate store and verify if its the right person who has sent the file? Please advice.
Because you did not provide what build management you use, I assume it will be Maven.
First, include BouncyCastle in your dependency
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.53</version>
</dependency>
After that, you need to make a util class that you will be using for sign or verify the certificate. Something like this:
package your.pack.location;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.bouncycastle.util.encoders.Base64;
import org.bouncycastle.util.io.pem.PemObject;
import org.bouncycastle.util.io.pem.PemReader;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
/**
* Author: harunalfat
*/
public class SignatureUtils {
private static final Logger log = LogManager.getLogger(SignatureUtils.class);
public static String sign(String plainText, PrivateKey privateKey) throws Exception {
byte[] data = plainText.getBytes("ISO-8859-1");
Signature signature = Signature.getInstance("SHA1WithRSA", "BC");
signature.initSign(privateKey);
signature.update(data);
return Base64.toBase64String(signature.sign());
}
public static boolean verify(String plainText, String signString, PublicKey publicKey) throws Exception{
byte[] data = plainText.getBytes("ISO-8859-1");
Signature signature = Signature.getInstance("SHA1WithRSA", "BC");
signature.initVerify(publicKey);
signature.update(data);
byte[] signByte = Base64.decode(signString);
return signature.verify(signByte);
}
private static PemObject getPemObjectFromResource(String fileLocation) throws IOException {
Resource resource = new ClassPathResource(fileLocation);
InputStream is = resource.getInputStream();
PemObject pemObject = new PemReader(new InputStreamReader( is )).readPemObject();
return pemObject;
}
private static X509EncodedKeySpec getPubKeySpec(String fileLocation) throws IOException, NoSuchAlgorithmException {
PemObject pemObject = getPemObjectFromResource(fileLocation);
byte[] data = pemObject.getContent();
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(data);
return keySpec;
}
private static PKCS8EncodedKeySpec getPriKeySpec(String fileLocation) throws IOException, NoSuchAlgorithmException {
PemObject pemObject = getPemObjectFromResource(fileLocation);
byte[] data = pemObject.getContent();
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(data);
return keySpec;
}
public static PublicKey getPublicKey(String fileLocation) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
KeyFactory kf = KeyFactory.getInstance("RSA");
KeySpec keySpec = getPubKeySpec(fileLocation);
return kf.generatePublic(keySpec);
}
public static PrivateKey getPrivateKey(String fileLocation) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
KeyFactory kf = KeyFactory.getInstance("RSA");
KeySpec keySpec = getPriKeySpec(fileLocation);
return kf.generatePrivate(keySpec);
}
}
And then you will use it like this
package your.another.pack;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.tomcat.util.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.junit.Test;
import org.mockito.MockitoAnnotations;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Security;
import static org.junit.Assert.assertTrue;
/**
* Author: harunalfat
*/
public class SignatureUtilsTest {
private static final Logger log = LogManager.getLogger(SignatureUtilsTest.class);
private static final String PLAIN = "attack at dawn";
#Test
public void testSignAndVerify() throws Exception {
Security.addProvider(new BouncyCastleProvider()); // <-- IMPORTANT!!! This will add BouncyCastle as provider in Java Security
PrivateKey privateKey = SignatureUtils.getPrivateKey("key/private2.pem"); // This is located on src/main/resources/key/private2.pem
PublicKey publicKey = SignatureUtils.getPublicKey("key/public2.pem"); // This is located on src/main/resources/key/public2.pem
// In this example, I use junit test, so it will be on src/test/resources/...
log.info("Private Key : "+Base64.encodeBase64String(privateKey.getEncoded()));
log.info("Public Key : "+Base64.encodeBase64String(publicKey.getEncoded()));
String sign = SignatureUtils.sign(PLAIN, privateKey);
log.info("Plain String : "+PLAIN);
log.info("Sign : "+sign);
boolean result = SignatureUtils.verify(PLAIN,sign, publicKey);
log.info("Result : "+result);
assertTrue(result);
}
}
Of course, you can change the Signature instance with another Algorithm. In my case I use "SHA1WithRSA", but you get the point right?
With this, someone will encrypt their data using their private key, and send it to you. After that, you will verify the data using the public key they give.
In example, Bob send to you message about money amount he sent to you ($5000), and sign it using their private key, become encrypted. When the data arrived to you, you know Bob supposed to send $5000, then you verify the encrypted data with text $5000 and public key Bob share, but is it really $5000 OR does it comes from Bob?
If the data has been changed, OR when someday you ask for some Money to Bob, but the message tapped by someone else and s/he send you the amount message with private key other than Bob's, you will know.
Feel free to ask :)
I have a symmetric Key in my JKS (Java Key Store) file, I want to wrap my private key with a symmetric key.
Again I am using wrappedBytes to PrivateKey Object. And finally I want the KeyPair Object.
The below code gives the following error message:
java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : DerInputStream.getLength(): lengthTag=125, too big.**
public KeyPair wrapPrivateKeyWithSymmetricKey(KeyPair keyPair) {
try {
PrivateKey priv = keyPair.getPrivate();
SecretKey symmetricKey = "bjksabfkasdbgvkasbvkkj";//symmetricKey from jks file
//wrapping Private Key
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.WRAP_MODE, symmetricKey);
byte[] wrappedKey = cipher.wrap(priv);
//wrappedKey bytes to PrivateKey Object
KeyFactory keyFactory = KeyFactory.getInstance(priv.getAlgorithm());
EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(wrappedKey);
PrivateKey privateKey2 = keyFactory.generatePrivate(privateKeySpec); //above Error Throwing in this line
return new KeyPair(keyPair.getPublic(), privateKey2);;
}
How can I solve this?
In your example, wrappedBytes isn't in a PKCS #8 format. It's simply some AES encrypted blocks—essentially random data—with no encoded structure.
If you want to create an encrypted PKCS #8 (formally, EncryptedPrivateKeyInfo) you'll need a library that handles that. The built-in API you are trying to use only handles its clear-text payload, PrivateKeyInfo (as described in its documentation).
There isn't much to the wrapper, and you could write the necessary DER coding yourself, or use a library like BouncyCastle.
Here's code, using BouncyCastle to encoded and decode the EncryptyedPrivateKeyInfo structure. The useless class provided by the JCE doesn't work, because of poor handling of the key encryption algorithm identifier and its parameters.
import java.security.GeneralSecurityException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPublicKeySpec;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.nist.NISTObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.EncryptedPrivateKeyInfo;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.pkcs.PKCS8EncryptedPrivateKeyInfo;
final class PKCS8
{
private static final ASN1ObjectIdentifier AES = ASN1ObjectIdentifier.getInstance(NISTObjectIdentifiers.id_aes128_CBC);
static RSAPublicKey toPublic(RSAPrivateCrtKey pvt)
throws GeneralSecurityException
{
RSAPublicKeySpec pub = new RSAPublicKeySpec(pvt.getModulus(), pvt.getPublicExponent());
KeyFactory f = KeyFactory.getInstance("RSA");
return (RSAPublicKey) f.generatePublic(pub);
}
static byte[] encrypt(SecretKey secret, PrivateKey pvt)
throws Exception
{
Cipher enc = Cipher.getInstance("AES/CBC/PKCS5Padding");
enc.init(Cipher.WRAP_MODE, secret);
ASN1Encodable params = new DEROctetString(enc.getIV());
AlgorithmIdentifier algId = new AlgorithmIdentifier(AES, params);
byte[] ciphertext = enc.wrap(pvt);
return new EncryptedPrivateKeyInfo(algId, ciphertext).getEncoded();
}
static PrivateKey decrypt(SecretKey secret, byte[] pkcs8)
throws Exception
{
EncryptedPrivateKeyInfo info = new PKCS8EncryptedPrivateKeyInfo(pkcs8).toASN1Structure();
AlgorithmIdentifier id = info.getEncryptionAlgorithm();
byte[] iv = ((ASN1OctetString) id.getParameters()).getOctets();
Cipher dec = Cipher.getInstance("AES/CBC/PKCS5Padding");
dec.init(Cipher.UNWRAP_MODE, secret, new IvParameterSpec(iv));
return (PrivateKey) dec.unwrap(info.getEncryptedData(), "RSA", Cipher.PRIVATE_KEY);
}
}
I am writing a JBenchX method that calculates a keys of CMSS signature using flexiprovider. I want to get timings for my method createKeys, but that is very very slow. Without annnotation #Bench that is too fast < 1 sec. Could you help to understand What's happen here?
import de.flexiprovider.api.exceptions.NoSuchAlgorithmException;
import de.flexiprovider.api.keys.KeyPair;
import de.flexiprovider.api.keys.KeyPairGenerator;
import org.jbenchx.annotations.Bench;
import org.jbenchx.annotations.ForEachInt;
import org.jbenchx.annotations.ForEachString;
import org.jbenchx.annotations.SingleRun;
public class CMSSTest {
#Bench
public Object createKeys(#ForEachString({ "CMSSwithSHA1andWinternitzOTS_1" }) String cmss) throws NoSuchAlgorithmException {
Security.addProvider(new FlexiPQCProvider());
//byte[] signatureBytes = null;
KeyPairGenerator kpg = (CMSSKeyPairGenerator) Registry
.getKeyPairGenerator(cmss);
KeyPair keyPair = kpg.genKeyPair();
}
}
The actual output is and is active yet.
Initializing Benchmarking Framework...
Running on Linux Linux
Max heap = 1345847296 System Benchmark = 11,8ns
Performing 1 benchmarking tasks..
[0] CMSSTest.createObjectArray(CMSSwithSHA1andWinternitzOTS_1)!*!**!!!******!!******!****!****!!******!!!!*******!******!****!*********************************
The problem seems to be that Registry.getKeyPairGenerator creates a new KeyPairGenerator which is initialized using a 'true' random seed. For this, the system potentially has to wait for enough entropy to be available. Therefore, you should not do this as part of the code that you want to benchmark.
Try something like this:
import java.security.Security;
import org.jbenchx.annotations.Bench;
import org.jbenchx.annotations.ForEachString;
import de.flexiprovider.api.Registry;
import de.flexiprovider.api.exceptions.NoSuchAlgorithmException;
import de.flexiprovider.api.keys.KeyPair;
import de.flexiprovider.api.keys.KeyPairGenerator;
import de.flexiprovider.pqc.FlexiPQCProvider;
public class CMSSTest {
static {
Security.addProvider(new FlexiPQCProvider());
}
private final KeyPairGenerator kpg;
public CMSSTest(#ForEachString({"CMSSwithSHA1andWinternitzOTS_1"}) String cmss) throws NoSuchAlgorithmException {
this.kpg = Registry.getKeyPairGenerator(cmss);
}
#Bench
public Object createKeys() {
KeyPair keyPair = kpg.genKeyPair();
return keyPair;
}
}
I want to sign a text file (may be a .exe file or something else in the future)
using PKCS#7 and verify the signature using Java.
What do I need to know?
Where will I find an API (.jar and documentation)?
What are the steps I need to follow in order to sign data and verify the data?
Please provide me code snippet if possible.
I reckon you need the following 2 Bouncy Castle jars to generate the PKCS7 digital signature:
bcprov-jdk15on-147.jar (for JDK 1.5 - JDK 1.7)
bcmail-jdk15on-147.jar (for JDK 1.5 - JDK 1.7)
You can download the Bouncy Castle jars from here.
You need to setup your keystore with the public & private key pair.
You need only the private key to generate the digital signature & the public key to verify it.
Here's how you'd pkcs7 sign content (Exception handling omitted for brevity) :
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.Security;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import org.bouncycastle.cert.jcajce.JcaCertStore;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.CMSSignedDataGenerator;
import org.bouncycastle.cms.CMSTypedData;
import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.operator.ContentSigner;
import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
import org.bouncycastle.util.Store;
import org.bouncycastle.util.encoders.Base64;
public final class PKCS7Signer {
private static final String PATH_TO_KEYSTORE = "/path/to/keyStore";
private static final String KEY_ALIAS_IN_KEYSTORE = "My_Private_Key";
private static final String KEYSTORE_PASSWORD = "MyPassword";
private static final String SIGNATUREALGO = "SHA1withRSA";
public PKCS7Signer() {
}
KeyStore loadKeyStore() throws Exception {
KeyStore keystore = KeyStore.getInstance("JKS");
InputStream is = new FileInputStream(PATH_TO_KEYSTORE);
keystore.load(is, KEYSTORE_PASSWORD.toCharArray());
return keystore;
}
CMSSignedDataGenerator setUpProvider(final KeyStore keystore) throws Exception {
Security.addProvider(new BouncyCastleProvider());
Certificate[] certchain = (Certificate[]) keystore.getCertificateChain(KEY_ALIAS_IN_KEYSTORE);
final List<Certificate> certlist = new ArrayList<Certificate>();
for (int i = 0, length = certchain == null ? 0 : certchain.length; i < length; i++) {
certlist.add(certchain[i]);
}
Store certstore = new JcaCertStore(certlist);
Certificate cert = keystore.getCertificate(KEY_ALIAS_IN_KEYSTORE);
ContentSigner signer = new JcaContentSignerBuilder(SIGNATUREALGO).setProvider("BC").
build((PrivateKey) (keystore.getKey(KEY_ALIAS_IN_KEYSTORE, KEYSTORE_PASSWORD.toCharArray())));
CMSSignedDataGenerator generator = new CMSSignedDataGenerator();
generator.addSignerInfoGenerator(new JcaSignerInfoGeneratorBuilder(new JcaDigestCalculatorProviderBuilder().setProvider("BC").
build()).build(signer, (X509Certificate) cert));
generator.addCertificates(certstore);
return generator;
}
byte[] signPkcs7(final byte[] content, final CMSSignedDataGenerator generator) throws Exception {
CMSTypedData cmsdata = new CMSProcessableByteArray(content);
CMSSignedData signeddata = generator.generate(cmsdata, true);
return signeddata.getEncoded();
}
public static void main(String[] args) throws Exception {
PKCS7Signer signer = new PKCS7Signer();
KeyStore keyStore = signer.loadKeyStore();
CMSSignedDataGenerator signatureGenerator = signer.setUpProvider(keyStore);
String content = "some bytes to be signed";
byte[] signedBytes = signer.signPkcs7(content.getBytes("UTF-8"), signatureGenerator);
System.out.println("Signed Encoded Bytes: " + new String(Base64.encode(signedBytes)));
}
}
PKCS#7 is known as CMS now (Cryptographic Message Syntax), and you will need the Bouncy Castle PKIX libraries to create one. It has ample documentation and a well established mailing list.
I won't supply code snippet, it is against house rules. Try yourself first.