// Copyright 2022 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 <stdlib.h>

#include <string.h>

#include <openssl/bytestring.h>

#include <openssl/ecdsa.h>

#include <openssl/mem.h>

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

  CBS cbs, body;

  CBS_ASN1_TAG tag;

  CBS_init(&cbs, buf, len);

  if (CBS_get_any_asn1(&cbs, &body, &tag)) {

    // DER has a unique encoding, so any parsed input should round-trip

    // correctly.

    size_t consumed = len - CBS_len(&cbs);

    bssl::ScopedCBB cbb;

    if (!CBB_init(cbb.get(), consumed) ||

        !CBB_add_asn1_element(cbb.get(), tag, CBS_data(&body),

                              CBS_len(&body)) ||

        CBB_len(cbb.get()) != consumed ||

        memcmp(CBB_data(cbb.get()), buf, consumed) != 0) {

      abort();

    }

  }

  ECDSA_SIG *sig = ECDSA_SIG_from_bytes(buf, len);

  if (sig != NULL) {

    uint8_t *enc;

    size_t enc_len;

    if (!ECDSA_SIG_to_bytes(&enc, &enc_len, sig) ||

        enc_len != len ||

        memcmp(buf, enc, len) != 0) {

      abort();

    }

    OPENSSL_free(enc);

    ECDSA_SIG_free(sig);

  }

  return 0;

}