text: /*
   * Written by Nils Larsch for the OpenSSL project.
   */
  /* ====================================================================
   * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    licensing@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  /* ====================================================================
   * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
   *
   * Portions of the attached software ("Contribution") are developed by
   * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
   *
   * The Contribution is licensed pursuant to the OpenSSL open source
   * license provided above.
   *
   * The elliptic curve binary polynomial software is originally written by
   * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include <openssl/opensslconf.h> /* To see if OPENSSL_NO_EC is defined */
  
  
  # include <openssl/crypto.h>
  # include <openssl/bio.h>
  # include <openssl/evp.h>
  # include <openssl/bn.h>
  # include <openssl/ec.h>
  # ifndef OPENSSL_NO_ENGINE
  #  include <openssl/engine.h>
  # endif
  # include <openssl/err.h>
  # include <openssl/rand.h>
  
  #ifndef stdout
  #define stdout ((void*)1)
  #endif
  #ifndef stderr
  #define stderr ((void*)2)
  #endif
  
  #ifdef PRINT_CHECKS
  #define BIO_printf(x, ...) printf(__VA_ARGS__)
  #else
  #define BIO_printf(x, ...)
  #endif
  static const char rnd_seed[] = "string to make the random number generator "
      "think it has entropy";
  
  /* declaration of the test functions */
  int x9_62_tests(BIO *);
  int x9_62_test_internal(BIO *out, int nid, const char *r, const char *s);
  int test_builtin(BIO *);
  
  /* functions to change the RAND_METHOD */
  int change_rand(void);
  int restore_rand(void);
  int fbytes(unsigned char *buf, int num);
  
  static RAND_METHOD fake_rand;
  static const RAND_METHOD *old_rand;
  
  int change_rand(void)
  {
      /* save old rand method */
      if ((old_rand = RAND_get_rand_method()) == NULL)
          return 0;
  
      fake_rand.seed = old_rand->seed;
      fake_rand.cleanup = old_rand->cleanup;
      fake_rand.add = old_rand->add;
      fake_rand.status = old_rand->status;
      /* use own random function */
      fake_rand.bytes = fbytes;
      fake_rand.pseudorand = old_rand->bytes;
      /* set new RAND_METHOD */
      if (!RAND_set_rand_method(&fake_rand))
          return 0;
      return 1;
  }
  
  int restore_rand(void)
  {
      if (!RAND_set_rand_method(old_rand))
          return 0;
      else
          return 1;
  }
  
  static int fbytes_counter = 0, use_fake = 0;
  static const char *numbers[8] = {
      "651056770906015076056810763456358567190100156695615665659",
      "6140507067065001063065065565667405560006161556565665656654",
      "8763001015071075675010661307616710783570106710677817767166"
          "71676178726717",
      "7000000175690566466555057817571571075705015757757057795755"
          "55657156756655",
      "1275552191113212300012030439187146164646146646466749494799",
      "1542725565216523985789236956265265265235675811949404040041",
      "1456427555219115346513212300075341203043918714616464614664"
          "64667494947990",
      "1712787255652165239672857892369562652652652356758119494040"
          "40041670216363"
  };
  
  int fbytes(unsigned char *buf, int num)
  {
      int ret;
      BIGNUM *tmp = NULL;
  
      if (use_fake == 0)
          return old_rand->bytes(buf, num);
  
      use_fake = 0;
  
      if (fbytes_counter >= 8)
          return 0;
      tmp = BN_new();
      if (!tmp)
          return 0;
      if (!BN_dec2bn(&tmp, numbers[fbytes_counter])) {
          BN_free(tmp);
          return 0;
      }
      fbytes_counter++;
      if (num != BN_num_bytes(tmp) || !BN_bn2bin(tmp, buf))
          ret = 0;
      else
          ret = 1;
      BN_free(tmp);
      return ret;
  }
  
  /* some tests from the X9.62 draft */
  int x9_62_test_internal(BIO *out, int nid, const char *r_in, const char *s_in)
  {
      int ret = 0;
      const char message[] = "abc";
      unsigned char digest[20];
      unsigned int dgst_len = 0;
      EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
      EC_KEY *key = NULL;
      ECDSA_SIG *signature = NULL;
      BIGNUM *r = NULL, *s = NULL;
      BIGNUM *kinv = NULL, *rp = NULL;
      const BIGNUM *sig_r, *sig_s;
  
      if (md_ctx == NULL)
          goto x962_int_err;
  
      /* get the message digest */
      if (!EVP_DigestInit(md_ctx, EVP_sha1())
          || !EVP_DigestUpdate(md_ctx, (const void *)message, 3)
          || !EVP_DigestFinal(md_ctx, digest, &dgst_len))
          goto x962_int_err;
  
      BIO_printf(out, "testing %s: ", OBJ_nid2sn(nid));
      /* create the key */
      if ((key = EC_KEY_new_by_curve_name(nid)) == NULL)
          goto x962_int_err;
      use_fake = 1;
      if (!EC_KEY_generate_key(key))
          goto x962_int_err;
      BIO_printf(out, ".");
      (void)BIO_flush(out);
      /* create the signature */
      use_fake = 1;
      /* Use ECDSA_sign_setup to avoid use of ECDSA nonces */
      if (!ECDSA_sign_setup(key, NULL, &kinv, &rp))
          goto x962_int_err;
      signature = ECDSA_do_sign_ex(digest, 20, kinv, rp, key);
      if (signature == NULL)
          goto x962_int_err;
      BIO_printf(out, ".");
      (void)BIO_flush(out);
      /* compare the created signature with the expected signature */
      if ((r = BN_new()) == NULL || (s = BN_new()) == NULL)
          goto x962_int_err;
      if (!BN_dec2bn(&r, r_in) || !BN_dec2bn(&s, s_in))
          goto x962_int_err;
      ECDSA_SIG_get0(signature, &sig_r, &sig_s);
      if (BN_cmp(sig_r, r) || BN_cmp(sig_s, s))
          goto x962_int_err;
      BIO_printf(out, ".");
      (void)BIO_flush(out);
      /* verify the signature */
      if (ECDSA_do_verify(digest, 20, signature, key) != 1)
          goto x962_int_err;
      BIO_printf(out, ".");
      (void)BIO_flush(out);
  
      BIO_printf(out, " ok\n");
      ret = 1;
   x962_int_err:
      if (!ret)
          BIO_printf(out, " failed\n");
      EC_KEY_free(key);
      ECDSA_SIG_free(signature);
      BN_free(r);
      BN_free(s);
      EVP_MD_CTX_free(md_ctx);
      BN_clear_free(kinv);
      BN_clear_free(rp);
      return ret;
  }
  
  int x9_62_tests(BIO *out)
  {
      int ret = 0;
  
      BIO_printf(out, "some tests from X9.62:\n");
  
      /* set own rand method */
      if (!change_rand())
          goto x962_err;
  
      if (!x9_62_test_internal(out, NID_X9_62_prime192v1,
                               "3342403536405981729393488334694600415596881826869351677613",
                               "5735822328888155254683894997897571951568553642892029982342"))
          goto x962_err;
      if (!x9_62_test_internal(out, NID_X9_62_prime239v1,
                               "3086361431751678114926225473006680188549593787585317781474"
                               "62058306432176",
                               "3238135532097973577080787768312505059318910517550078427819"
                               "78505179448783"))
          goto x962_err;
  # ifndef OPENSSL_NO_EC2M
      if (!x9_62_test_internal(out, NID_X9_62_c2tnb191v1,
                               "87194383164871543355722284926904419997237591535066528048",
                               "308992691965804947361541664549085895292153777025772063598"))
          goto x962_err;
      if (!x9_62_test_internal(out, NID_X9_62_c2tnb239v1,
                               "2159633321041961198501834003903461262881815148684178964245"
                               "5876922391552",
                               "1970303740007316867383349976549972270528498040721988191026"
                               "49413465737174"))
          goto x962_err;
  # endif
      ret = 1;
   x962_err:
      if (!restore_rand())
          ret = 0;
      return ret;
  }
  
  int test_builtin(BIO *out)
  {
      EC_builtin_curve *curves = NULL;
      size_t crv_len = 0, n = 0;
      EC_KEY *eckey = NULL, *wrong_eckey = NULL;
      EC_GROUP *group;
      ECDSA_SIG *ecdsa_sig = NULL, *modified_sig = NULL;
      unsigned char digest[20], wrong_digest[20];
      unsigned char *signature = NULL;
      const unsigned char *sig_ptr;
      unsigned char *sig_ptr2;
      unsigned char *raw_buf = NULL;
      const BIGNUM *sig_r, *sig_s;
      BIGNUM *modified_r = NULL, *modified_s = NULL;
      BIGNUM *unmodified_r = NULL, *unmodified_s = NULL;
      unsigned int sig_len, degree, r_len, s_len, bn_len, buf_len;
      int nid, ret = 0;
  
      /* fill digest values with some random data */
      if (RAND_bytes(digest, 20) <= 0 || RAND_bytes(wrong_digest, 20) <= 0) {
          BIO_printf(out, "ERROR: unable to get random data\n");
          goto builtin_err;
      }
  
      /*
       * create and verify a ecdsa signature with every availble curve (with )
       */
      BIO_printf(out, "\ntesting ECDSA_sign() and ECDSA_verify() "
                 "with some internal curves:\n");
  
      /* get a list of all internal curves */
      crv_len = EC_get_builtin_curves(NULL, 0);
      curves = OPENSSL_malloc(sizeof(*curves) * crv_len);
      if (curves == NULL) {
          BIO_printf(out, "malloc error\n");
          goto builtin_err;
      }
  
      if (!EC_get_builtin_curves(curves, crv_len)) {
          BIO_printf(out, "unable to get internal curves\n");
          goto builtin_err;
      }
  
      /* now create and verify a signature for every curve */
      for (n = 0; n < crv_len; n++) {
          unsigned char dirt, offset;
  
          nid = curves[n].nid;
          if (nid == NID_ipsec4 || nid == NID_X25519)
              continue;
          /* create new ecdsa key (== EC_KEY) */
          if ((eckey = EC_KEY_new()) == NULL)
              goto builtin_err;
          group = EC_GROUP_new_by_curve_name(nid);
          if (group == NULL)
              goto builtin_err;
          if (EC_KEY_set_group(eckey, group) == 0)
              goto builtin_err;
          EC_GROUP_free(group);
          degree = EC_GROUP_get_degree(EC_KEY_get0_group(eckey));
          if (degree < 160) {
              /* drop the curve */
              EC_KEY_free(eckey);
              eckey = NULL;
              continue;
          }
          BIO_printf(out, "%s: ", OBJ_nid2sn(nid));
          /* create key */
          if (!EC_KEY_generate_key(eckey)) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          /* create second key */
          if ((wrong_eckey = EC_KEY_new()) == NULL)
              goto builtin_err;
          group = EC_GROUP_new_by_curve_name(nid);
          if (group == NULL)
              goto builtin_err;
          if (EC_KEY_set_group(wrong_eckey, group) == 0)
              goto builtin_err;
          EC_GROUP_free(group);
          if (!EC_KEY_generate_key(wrong_eckey)) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
  
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* check key */
          if (!EC_KEY_check_key(eckey)) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* create signature */
          sig_len = ECDSA_size(eckey);
          if ((signature = OPENSSL_malloc(sig_len)) == NULL)
              goto builtin_err;
          if (!ECDSA_sign(0, digest, 20, signature, &sig_len, eckey)) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* verify signature */
          if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) != 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* verify signature with the wrong key */
          if (ECDSA_verify(0, digest, 20, signature, sig_len, wrong_eckey) == 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* wrong digest */
          if (ECDSA_verify(0, wrong_digest, 20, signature, sig_len, eckey) == 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
          /* wrong length */
          if (ECDSA_verify(0, digest, 20, signature, sig_len - 1, eckey) == 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
  
          /*
           * Modify a single byte of the signature: to ensure we don't garble
           * the ASN1 structure, we read the raw signature and modify a byte in
           * one of the bignums directly.
           */
          sig_ptr = signature;
          if ((ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr, sig_len)) == NULL) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
  
          ECDSA_SIG_get0(ecdsa_sig, &sig_r, &sig_s);
  
          /* Store the two BIGNUMs in raw_buf. */
          r_len = BN_num_bytes(sig_r);
          s_len = BN_num_bytes(sig_s);
          bn_len = (degree + 7) / 8;
          if ((r_len > bn_len) || (s_len > bn_len)) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          buf_len = 2 * bn_len;
          if ((raw_buf = OPENSSL_zalloc(buf_len)) == NULL)
              goto builtin_err;
          BN_bn2bin(sig_r, raw_buf + bn_len - r_len);
          BN_bn2bin(sig_s, raw_buf + buf_len - s_len);
  
  		/* Modify a single byte in the buffer. */
          offset = raw_buf[10] % buf_len;
          dirt = raw_buf[11] ? raw_buf[11] : 1;
          raw_buf[offset] ^= dirt;
          /* Now read the BIGNUMs back in from raw_buf. */
          modified_sig = ECDSA_SIG_new();
          if (modified_sig == NULL)
              goto builtin_err;
          if (((modified_r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL)
              || ((modified_s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL)
              || !ECDSA_SIG_set0(modified_sig, modified_r, modified_s)) {
              BN_free(modified_r);
              BN_free(modified_s);
              goto builtin_err;
          }
          sig_ptr2 = signature;
          sig_len = i2d_ECDSA_SIG(modified_sig, &sig_ptr2);
          if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) == 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          
          /*
           * Sanity check: undo the modification and verify signature.
           */
          raw_buf[offset] ^= dirt;
          if (((unmodified_r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL)
              || ((unmodified_s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL)
              || !ECDSA_SIG_set0(modified_sig, unmodified_r, unmodified_s)) {
              BN_free(unmodified_r);
              BN_free(unmodified_s);
              goto builtin_err;
          }
  
          sig_ptr2 = signature;
          sig_len = i2d_ECDSA_SIG(modified_sig, &sig_ptr2);
          if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) != 1) {
              BIO_printf(out, " failed\n");
              goto builtin_err;
          }
          BIO_printf(out, ".");
          (void)BIO_flush(out);
  
          BIO_printf(out, " ok\n");
          /* cleanup */
          /* clean bogus errors */
          ERR_clear_error();
          OPENSSL_free(signature);
          signature = NULL;
          EC_KEY_free(eckey);
          eckey = NULL;
          EC_KEY_free(wrong_eckey);
          wrong_eckey = NULL;
          ECDSA_SIG_free(ecdsa_sig);
          ecdsa_sig = NULL;
          ECDSA_SIG_free(modified_sig);
          modified_sig = NULL;
          OPENSSL_free(raw_buf);
          raw_buf = NULL;
      }
  
      ret = 1;
   builtin_err:
      EC_KEY_free(eckey);
      EC_KEY_free(wrong_eckey);
      ECDSA_SIG_free(ecdsa_sig);
      ECDSA_SIG_free(modified_sig);
      OPENSSL_free(signature);
      OPENSSL_free(raw_buf);
      OPENSSL_free(curves);
  
      return ret;
  }
  
  char* getenv(char* name);
  
  int ecdsa_test()
  {
      int ret = 1;
      BIO *out = NULL;
  
      /* initialize the prng */
      RAND_seed(rnd_seed, sizeof(rnd_seed));
  
      /* the tests */
      if (!x9_62_tests(out))
          goto err;
      if (!test_builtin(out))
          goto err;
  
      ret = 0;
   err:
      if (ret)
          BIO_printf(out, "\nECDSA test failed\n");
      else
          BIO_printf(out, "\nECDSA test passed\n");
      if (ret)
          ERR_print_errors(out);
  
  #ifndef OPENSSL_NO_CRYPTO_MDEBUG
      if (CRYPTO_mem_leaks(out) <= 0)
          ret = 1;
  #endif
      BIO_free(out);
      return ret;
  }
  