// Copyright 2016 The BoringSSL Authors

//

// 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

//

//     https://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.

#include <openssl/err.h>

#include <openssl/mem.h>

#include <openssl/x509.h>

#include "../crypto/x509/internal.h"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {

  bssl::UniquePtr<X509> x509(d2i_X509(nullptr, &buf, len));

  if (x509 != nullptr) {

    // Extract the public key.

    EVP_PKEY_free(X509_get_pubkey(x509.get()));

    // Fuzz some deferred parsing.

    x509v3_cache_extensions(x509.get());

    // Fuzz every supported extension.

    for (int i = 0; i < X509_get_ext_count(x509.get()); i++) {

      const X509_EXTENSION *ext = X509_get_ext(x509.get(), i);

      void *parsed = X509V3_EXT_d2i(ext);

      if (parsed != nullptr) {

        int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext));

        BSSL_CHECK(nid != NID_undef);

        // Reserialize the extension. This should succeed if we were able to

        // parse it.

        // TODO(crbug.com/boringssl/352): Ideally we would also assert that

        // |new_ext| is identical to |ext|, but our parser is not strict enough.

        bssl::UniquePtr<X509_EXTENSION> new_ext(

            X509V3_EXT_i2d(nid, X509_EXTENSION_get_critical(ext), parsed));

        BSSL_CHECK(new_ext != nullptr);

        // This can only fail if |ext| was not a supported type, but then

        // |X509V3_EXT_d2i| should have failed.

        BSSL_CHECK(X509V3_EXT_free(nid, parsed));

      }

    }

    // Reserialize |x509|. This should succeed if we were able to parse it.

    // TODO(crbug.com/boringssl/352): Ideally we would also assert the output

    // matches the input, but our parser is not strict enough.

    uint8_t *der = nullptr;

    int der_len = i2d_X509(x509.get(), &der);

    BSSL_CHECK(der_len > 0);

    OPENSSL_free(der);

    // Reserialize |x509|'s TBSCertificate without reusing the cached encoding.

    // TODO(crbug.com/boringssl/352): Ideally we would also assert the output

    // matches the input TBSCertificate, but our parser is not strict enough.

    der = nullptr;

    der_len = i2d_re_X509_tbs(x509.get(), &der);

    BSSL_CHECK(der_len > 0);

    OPENSSL_free(der);

    BIO *bio = BIO_new(BIO_s_mem());

    X509_print(bio, x509.get());

    BIO_free(bio);

  }

  ERR_clear_error();

  return 0;

}