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Code Issues Releases Wiki Activity

Crypto: Add basic asymmetric encryption methods

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This commit is contained in:
Tom Hacohen 2017-04-13 13:33:17 +01:00
parent 89731519e9
commit e836b4c716
2 changed files with 103 additions and 3 deletions
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89
app/src/main/java/com/etesync/syncadapter/journalmanager/Crypto.java
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@ -7,11 +7,18 @@ import com.etesync.syncadapter.utils.Base64;
import org.apache.commons.codec.Charsets;
import org.apache.commons.lang3.ArrayUtils;
import org.spongycastle.asn1.pkcs.PrivateKeyInfo;
import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
import org.spongycastle.crypto.AsymmetricBlockCipher;
import org.spongycastle.crypto.AsymmetricCipherKeyPair;
import org.spongycastle.crypto.BufferedBlockCipher;
import org.spongycastle.crypto.CipherParameters;
import org.spongycastle.crypto.InvalidCipherTextException;
import org.spongycastle.crypto.digests.SHA256Digest;
import org.spongycastle.crypto.encodings.OAEPEncoding;
import org.spongycastle.crypto.engines.AESEngine;
import org.spongycastle.crypto.engines.RSAEngine;
import org.spongycastle.crypto.generators.RSAKeyPairGenerator;
import org.spongycastle.crypto.generators.SCrypt;
import org.spongycastle.crypto.macs.HMac;
import org.spongycastle.crypto.modes.CBCBlockCipher;
@ -20,12 +27,21 @@ import org.spongycastle.crypto.paddings.PKCS7Padding;
import org.spongycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.spongycastle.crypto.params.KeyParameter;
import org.spongycastle.crypto.params.ParametersWithIV;
import org.spongycastle.crypto.params.RSAKeyGenerationParameters;
import org.spongycastle.crypto.util.PrivateKeyFactory;
import org.spongycastle.crypto.util.PrivateKeyInfoFactory;
import org.spongycastle.crypto.util.PublicKeyFactory;
import org.spongycastle.crypto.util.SubjectPublicKeyInfoFactory;
import org.spongycastle.util.encoders.Hex;
import java.io.IOException;
import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.Arrays;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
public class Crypto {
public static String deriveKey(String salt, String password) {
@ -34,6 +50,73 @@ public class Crypto {
return Base64.encodeToString(SCrypt.generate(password.getBytes(Charsets.UTF_8), salt.getBytes(Charsets.UTF_8), 16384, 8, 1, keySize), Base64.NO_WRAP);
}
public static AsymmetricKeyPair generateKeyPair() {
RSAKeyPairGenerator keyPairGenerator = new RSAKeyPairGenerator();
keyPairGenerator.init(new RSAKeyGenerationParameters(BigInteger.valueOf(65537), new SecureRandom(), 2048, 160));
AsymmetricCipherKeyPair keyPair = keyPairGenerator.generateKeyPair();
try {
PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.createPrivateKeyInfo(keyPair.getPrivate());
SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.createSubjectPublicKeyInfo(keyPair.getPublic());
return new AsymmetricKeyPair(privateKeyInfo.getEncoded(), publicKeyInfo.getEncoded());
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@RequiredArgsConstructor
public static class AsymmetricKeyPair {
@Getter(AccessLevel.PUBLIC)
private final byte[] privateKey;
@Getter(AccessLevel.PUBLIC)
private final byte[] publicKey;
}
public static class AsymmetricCryptoManager {
private final AsymmetricKeyPair keyPair;
public AsymmetricCryptoManager(AsymmetricKeyPair keyPair) {
this.keyPair = keyPair;
}
public byte[] encrypt(byte[] pubkey, byte[] content) {
AsymmetricBlockCipher cipher = new RSAEngine();
cipher = new OAEPEncoding(cipher);
try {
cipher.init(true, PublicKeyFactory.createKey(pubkey));
return cipher.processBlock(content, 0, content.length);
} catch (IOException e) {
e.printStackTrace();
} catch (InvalidCipherTextException e) {
e.printStackTrace();
App.log.severe("Invalid ciphertext: " + Base64.encodeToString(content, Base64.NO_WRAP));
}
return null;
}
public byte[] decrypt(byte[] cipherText) {
AsymmetricBlockCipher cipher = new RSAEngine();
cipher = new OAEPEncoding(cipher);
try {
cipher.init(false, PrivateKeyFactory.createKey(keyPair.getPrivateKey()));
return cipher.processBlock(cipherText, 0, cipherText.length);
} catch (IOException e) {
e.printStackTrace();
} catch (InvalidCipherTextException e) {
e.printStackTrace();
App.log.severe("Invalid ciphertext: " + Base64.encodeToString(cipherText, Base64.NO_WRAP));
}
return null;
}
public static byte[] getKeyFingerprint(byte[] pubkey) {
return sha256(pubkey);
}
}
public static class CryptoManager {
final static int HMAC_SIZE = 256 / 8; // hmac256 in bytes
@ -146,15 +229,15 @@ public class Crypto {
}
static String sha256(String base) {
return sha256(base.getBytes(Charsets.UTF_8));
return toHex(sha256(base.getBytes(Charsets.UTF_8)));
}
private static String sha256(byte[] base) {
private static byte[] sha256(byte[] base) {
SHA256Digest digest = new SHA256Digest();
digest.update(base, 0, base.length);
byte[] ret = new byte[digest.getDigestSize()];
digest.doFinal(ret, 0);
return toHex(ret);
return ret;
}
static String toHex(byte[] bytes) {

17
app/src/test/java/com/etesync/syncadapter/journalmanager/EncryptionTest.java
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@ -14,9 +14,11 @@ import org.apache.commons.codec.Charsets;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.spongycastle.util.encoders.Hex;
import java.io.IOException;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
public class EncryptionTest {
@ -67,4 +69,19 @@ public class EncryptionTest {
public void testCryptoVersionOutOfRange() throws Exceptions.IntegrityException, Exceptions.VersionTooNewException {
new Crypto.CryptoManager(999, Helpers.keyBase64, "TestSaltShouldBeJournalId");
}
@Test
public void testAsymCrypto() throws Exceptions.IntegrityException, Exceptions.GenericCryptoException {
Crypto.AsymmetricKeyPair keyPair = Crypto.generateKeyPair();
Crypto.AsymmetricCryptoManager cryptoManager = new Crypto.AsymmetricCryptoManager(keyPair);
byte[] clearText = "This Is Some Test Cleartext.".getBytes(Charsets.UTF_8);
byte[] cipher = cryptoManager.encrypt(keyPair.getPublicKey(), clearText);
byte[] clearText2 = cryptoManager.decrypt(cipher);
assertArrayEquals(clearText, clearText2);
// Mostly for coverage. Make sure it's the expected sha256 value.
assertEquals("ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb",
Hex.toHexString(Crypto.AsymmetricCryptoManager.getKeyFingerprint("a".getBytes(Charsets.UTF_8))).toLowerCase());
}
}