java/src/test/java/com/google/crypto/tink/subtle/RsaSsaPkcs1VerifyJceTest.java

// Copyright 2018 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////////

package com.google.crypto.tink.subtle;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

import com.google.crypto.tink.TestUtil;
import com.google.crypto.tink.WycheproofTestUtil;
import com.google.crypto.tink.subtle.Enums.HashType;
import java.security.GeneralSecurityException;
import java.security.KeyFactory;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.X509EncodedKeySpec;
import org.json.JSONArray;
import org.json.JSONObject;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Unit tests for RsaSsaPkcs1VerifyJce. */
@RunWith(JUnit4.class)
public class RsaSsaPkcs1VerifyJceTest {

  @Test
  public void testConstructorExceptions() throws Exception {
    int keySize = 2048;
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
    keyGen.initialize(keySize);
    RSAPublicKey pub = (RSAPublicKey) keyGen.generateKeyPair().getPublic();
    try {
      new RsaSsaPkcs1VerifyJce(pub, HashType.SHA1);
      fail("Unsafe hash, should have thrown exception.");
    } catch (GeneralSecurityException e) {
      // Expected.
      TestUtil.assertExceptionContains(e, "Unsupported hash: SHA1");
    }
  }

  @Test
  public void testWycheproofVectors() throws Exception {
    testWycheproofVectors("../wycheproof/testvectors/rsa_signature_2048_sha256_test.json");
    testWycheproofVectors("../wycheproof/testvectors/rsa_signature_3072_sha512_test.json");
    testWycheproofVectors("../wycheproof/testvectors/rsa_signature_4096_sha512_test.json");
  }

  private static void testWycheproofVectors(String fileName) throws Exception {
    JSONObject jsonObj = WycheproofTestUtil.readJson(fileName);

    int errors = 0;
    JSONArray testGroups = jsonObj.getJSONArray("testGroups");
    for (int i = 0; i < testGroups.length(); i++) {
      JSONObject group = testGroups.getJSONObject(i);

      KeyFactory kf = KeyFactory.getInstance("RSA");
      byte[] encodedPubKey = Hex.decode(group.getString("keyDer"));
      X509EncodedKeySpec x509keySpec = new X509EncodedKeySpec(encodedPubKey);
      String sha = group.getString("sha");
      HashType hash = WycheproofTestUtil.getHashType(sha);

      JSONArray tests = group.getJSONArray("tests");
      for (int j = 0; j < tests.length(); j++) {
        JSONObject testcase = tests.getJSONObject(j);
        String tcId =
            String.format(
                "testcase %d (%s)", testcase.getInt("tcId"), testcase.getString("comment"));
        RsaSsaPkcs1VerifyJce verifier;
        RSAPublicKey pubKey = (RSAPublicKey) kf.generatePublic(x509keySpec);
        verifier = new RsaSsaPkcs1VerifyJce(pubKey, hash);
        byte[] msg = getMessage(testcase);
        byte[] sig = Hex.decode(testcase.getString("sig"));
        String result = testcase.getString("result");
        try {
          verifier.verify(sig, msg);
          if (result.equals("invalid")) {
            System.out.printf("FAIL %s: accepting invalid signature%n", tcId);
            errors++;
          }
        } catch (GeneralSecurityException ex) {
          if (result.equals("valid")) {
            System.out.printf("FAIL %s: rejecting valid signature, exception: %s%n", tcId, ex);
            errors++;
          }
        }
      }
    }
    assertEquals(0, errors);
  }

  private static byte[] getMessage(JSONObject testcase) throws Exception {
    // Previous version of Wycheproof test vectors uses "message" while the new one uses "msg".
    if (testcase.has("msg")) {
      return Hex.decode(testcase.getString("msg"));
    } else {
      return Hex.decode(testcase.getString("message"));
    }
  }
}