/* Copyright (c) 2017, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

// cavp_ecdsa2_sigver_test processes a NIST CAVP ECDSA2 SigVer test vector
// request file and emits the corresponding response. An optional sample vector
// file can be passed to verify the result.

#include <vector>

#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/digest.h>
#include <openssl/ec_key.h>
#include <openssl/ecdsa.h>
#include <openssl/err.h>
#include <openssl/nid.h>

#include "../test/file_test.h"
#include "cavp_test_util.h"


static bool TestECDSA2SigVer(FileTest *t, void *arg) {
  int nid = GetECGroupNIDFromInstruction(t);
  const EVP_MD *md = GetDigestFromInstruction(t);
  if (nid == NID_undef || md == nullptr) {
    return false;
  }
  bssl::UniquePtr<ECDSA_SIG> sig(ECDSA_SIG_new());
  bssl::UniquePtr<EC_KEY> key(EC_KEY_new_by_curve_name(nid));
  bssl::UniquePtr<BIGNUM> qx = GetBIGNUM(t, "Qx");
  bssl::UniquePtr<BIGNUM> qy = GetBIGNUM(t, "Qy");
  bssl::UniquePtr<BIGNUM> r = GetBIGNUM(t, "R");
  bssl::UniquePtr<BIGNUM> s = GetBIGNUM(t, "S");
  std::vector<uint8_t> msg;
  uint8_t digest[EVP_MAX_MD_SIZE];
  unsigned digest_len;
  if (!sig || !key || !qx || !qy || !r || !s ||
      !EC_KEY_set_public_key_affine_coordinates(key.get(), qx.get(),
                                                qy.get()) ||
      !t->GetBytes(&msg, "Msg") ||
      !EVP_Digest(msg.data(), msg.size(), digest, &digest_len, md, nullptr)) {
    return false;
  }

  BN_free(sig->r);
  sig->r = r.release();
  BN_free(sig->s);
  sig->s = s.release();

  if (ECDSA_do_verify(digest, digest_len, sig.get(), key.get())) {
    printf("%sResult = P\r\n\r\n", t->CurrentTestToString().c_str());
  } else {
    char buf[256];
    ERR_error_string_n(ERR_get_error(), buf, sizeof(buf));
    printf("%sResult = F (%s)\r\n\r\n", t->CurrentTestToString().c_str(), buf);
  }
  ERR_clear_error();
  return true;
}

int main(int argc, char **argv) {
  CRYPTO_library_init();

  if (argc != 2) {
    fprintf(stderr, "usage: %s <test file>\n",
            argv[0]);
    return 1;
  }

  printf("# Generated by");
  for (int i = 0; i < argc; i++) {
    printf(" %s", argv[i]);
  }
  printf("\r\n\r\n");

  return FileTestMainSilent(TestECDSA2SigVer, nullptr, argv[1]);
}