text: /*
   * Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved.
   * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  /*
   * Low level APIs are deprecated for public use, but still ok for internal use.
   */
  #include "internal/deprecated.h"
  
  #include <openssl/opensslconf.h> /* To see if OPENSSL_NO_EC is defined */
  #include "testutil.h"
  
  #ifndef OPENSSL_NO_EC
  
  # include <openssl/evp.h>
  # include <openssl/bn.h>
  # include <openssl/ec.h>
  # include <openssl/rand.h>
  # include "internal/nelem.h"
  # include "ecdsatest.h"
  
  static fake_random_generate_cb fbytes;
  
  static const char *numbers[2];
  static size_t crv_len = 0;
  static EC_builtin_curve *curves = NULL;
  static OSSL_PROVIDER *fake_rand = NULL;
  
  static int fbytes(unsigned char *buf, size_t num, ossl_unused const char *name,
                    EVP_RAND_CTX *ctx)
  {
      int ret = 0;
      static int fbytes_counter = 0;
      BIGNUM *tmp = NULL;
  
      fake_rand_set_callback(ctx, NULL);
  
      if (!TEST_ptr(tmp = BN_new())
          || !TEST_int_lt(fbytes_counter, OSSL_NELEM(numbers))
          || !TEST_true(BN_hex2bn(&tmp, numbers[fbytes_counter]))
          /* tmp might need leading zeros so pad it out */
          || !TEST_int_le(BN_num_bytes(tmp), num)
          || !TEST_true(BN_bn2binpad(tmp, buf, num)))
          goto err;
  
      fbytes_counter = (fbytes_counter + 1) % OSSL_NELEM(numbers);
      ret = 1;
   err:
      BN_free(tmp);
      return ret;
  }
  
  /*-
   * This function hijacks the RNG to feed it the chosen ECDSA key and nonce.
   * The ECDSA KATs are from:
   * - the X9.62 draft (4)
   * - NIST CAVP (720)
   *
   * It uses the low-level ECDSA_sign_setup instead of EVP to control the RNG.
   * NB: This is not how applications should use ECDSA; this is only for testing.
   *
   * Tests the library can successfully:
   * - generate public keys that matches those KATs
   * - create ECDSA signatures that match those KATs
   * - accept those signatures as valid
   */
  static int x9_62_tests(int n)
  {
      int nid, md_nid, ret = 0;
      const char *r_in = NULL, *s_in = NULL, *tbs = NULL;
      unsigned char *pbuf = NULL, *qbuf = NULL, *message = NULL;
      unsigned char digest[EVP_MAX_MD_SIZE];
      unsigned int dgst_len = 0;
      long q_len, msg_len = 0;
      size_t p_len;
      EVP_MD_CTX *mctx = NULL;
      EC_KEY *key = NULL;
      ECDSA_SIG *signature = NULL;
      BIGNUM *r = NULL, *s = NULL;
      BIGNUM *kinv = NULL, *rp = NULL;
      const BIGNUM *sig_r = NULL, *sig_s = NULL;
  
      nid = ecdsa_cavs_kats[n].nid;
      md_nid = ecdsa_cavs_kats[n].md_nid;
      r_in = ecdsa_cavs_kats[n].r;
      s_in = ecdsa_cavs_kats[n].s;
      tbs = ecdsa_cavs_kats[n].msg;
      numbers[0] = ecdsa_cavs_kats[n].d;
      numbers[1] = ecdsa_cavs_kats[n].k;
  
      TEST_info("ECDSA KATs for curve %s", OBJ_nid2sn(nid));
  
  #ifdef FIPS_MODULE
      if (EC_curve_nid2nist(nid) == NULL)
          return TEST_skip("skip non approved curves");
  #endif /* FIPS_MODULE */
  
      if (!TEST_ptr(mctx = EVP_MD_CTX_new())
          /* get the message digest */
          || !TEST_ptr(message = OPENSSL_hexstr2buf(tbs, &msg_len))
          || !TEST_true(EVP_DigestInit_ex(mctx, EVP_get_digestbynid(md_nid), NULL))
          || !TEST_true(EVP_DigestUpdate(mctx, message, msg_len))
          || !TEST_true(EVP_DigestFinal_ex(mctx, digest, &dgst_len))
          /* create the key */
          || !TEST_ptr(key = EC_KEY_new_by_curve_name(nid))
          /* load KAT variables */
          || !TEST_ptr(r = BN_new())
          || !TEST_ptr(s = BN_new())
          || !TEST_true(BN_hex2bn(&r, r_in))
          || !TEST_true(BN_hex2bn(&s, s_in)))
          goto err;
  
      /* public key must match KAT */
      fake_rand_set_callback(RAND_get0_private(NULL), &fbytes);
      if (!TEST_true(EC_KEY_generate_key(key))
          || !TEST_true(p_len = EC_KEY_key2buf(key, POINT_CONVERSION_UNCOMPRESSED,
                                               &pbuf, NULL))
          || !TEST_ptr(qbuf = OPENSSL_hexstr2buf(ecdsa_cavs_kats[n].Q, &q_len))
          || !TEST_int_eq(q_len, p_len)
          || !TEST_mem_eq(qbuf, q_len, pbuf, p_len))
          goto err;
  
      /* create the signature via ECDSA_sign_setup to avoid use of ECDSA nonces */
      fake_rand_set_callback(RAND_get0_private(NULL), &fbytes);
      if (!TEST_true(ECDSA_sign_setup(key, NULL, &kinv, &rp))
          || !TEST_ptr(signature = ECDSA_do_sign_ex(digest, dgst_len,
                                                    kinv, rp, key))
          /* verify the signature */
          || !TEST_int_eq(ECDSA_do_verify(digest, dgst_len, signature, key), 1))
          goto err;
  
      /* compare the created signature with the expected signature */
      ECDSA_SIG_get0(signature, &sig_r, &sig_s);
      if (!TEST_BN_eq(sig_r, r)
          || !TEST_BN_eq(sig_s, s))
          goto err;
  
      ret = 1;
  
   err:
      OPENSSL_free(message);
      OPENSSL_free(pbuf);
      OPENSSL_free(qbuf);
      EC_KEY_free(key);
      ECDSA_SIG_free(signature);
      BN_free(r);
      BN_free(s);
      EVP_MD_CTX_free(mctx);
      BN_clear_free(kinv);
      BN_clear_free(rp);
      return ret;
  }
  
  /*-
   * Positive and negative ECDSA testing through EVP interface:
   * - EVP_DigestSign (this is the one-shot version)
   * - EVP_DigestVerify
   *
   * Tests the library can successfully:
   * - create a key
   * - create a signature
   * - accept that signature
   * - reject that signature with a different public key
   * - reject that signature if its length is not correct
   * - reject that signature after modifying the message
   * - accept that signature after un-modifying the message
   * - reject that signature after modifying the signature
   * - accept that signature after un-modifying the signature
   */
  static int set_sm2_id(EVP_MD_CTX *mctx, EVP_PKEY *pkey)
  {
      /* With the SM2 key type, the SM2 ID is mandatory */
      static const char sm2_id[] = { 1, 2, 3, 4, 'l', 'e', 't', 't', 'e', 'r' };
      EVP_PKEY_CTX *pctx;
  
      if (!TEST_ptr(pctx = EVP_MD_CTX_pkey_ctx(mctx))
          || !TEST_int_gt(EVP_PKEY_CTX_set1_id(pctx, sm2_id, sizeof(sm2_id)), 0))
          return 0;
      return 1;
  }
  
  static int test_builtin(int n, int as)
  {
      EC_KEY *eckey_neg = NULL, *eckey = NULL;
      unsigned char dirt, offset, tbs[128];
      unsigned char *sig = NULL;
      EVP_PKEY *pkey_neg = NULL, *pkey = NULL, *dup_pk = NULL;
      EVP_MD_CTX *mctx = NULL;
      size_t sig_len;
      int nid, ret = 0;
      int temp;
  
      nid = curves[n].nid;
  
      /* skip built-in curves where ord(G) is not prime */
      if (nid == NID_ipsec4 || nid == NID_ipsec3) {
          TEST_info("skipped: ECDSA unsupported for curve %s", OBJ_nid2sn(nid));
          return 1;
      }
  
      /*
       * skip SM2 curve if 'as' is equal to EVP_PKEY_EC or, skip all curves
       * except SM2 curve if 'as' is equal to EVP_PKEY_SM2
       */
      if (nid == NID_sm2 && as == EVP_PKEY_EC) {
          TEST_info("skipped: EC key type unsupported for curve %s",
                    OBJ_nid2sn(nid));
          return 1;
      } else if (nid != NID_sm2 && as == EVP_PKEY_SM2) {
          TEST_info("skipped: SM2 key type unsupported for curve %s",
                    OBJ_nid2sn(nid));
          return 1;
      }
  
      TEST_info("testing ECDSA for curve %s as %s key type", OBJ_nid2sn(nid),
                as == EVP_PKEY_EC ? "EC" : "SM2");
  
      if (!TEST_ptr(mctx = EVP_MD_CTX_new())
          /* get some random message data */
          || !TEST_true(RAND_bytes(tbs, sizeof(tbs)))
          /* real key */
          || !TEST_ptr(eckey = EC_KEY_new_by_curve_name(nid))
          || !TEST_true(EC_KEY_generate_key(eckey))
          || !TEST_ptr(pkey = EVP_PKEY_new())
          || !TEST_true(EVP_PKEY_assign_EC_KEY(pkey, eckey))
          /* fake key for negative testing */
          || !TEST_ptr(eckey_neg = EC_KEY_new_by_curve_name(nid))
          || !TEST_true(EC_KEY_generate_key(eckey_neg))
          || !TEST_ptr(pkey_neg = EVP_PKEY_new())
          || !TEST_false(EVP_PKEY_assign_EC_KEY(pkey_neg, NULL))
          || !TEST_true(EVP_PKEY_assign_EC_KEY(pkey_neg, eckey_neg)))
          goto err;
  
      if (!TEST_ptr(dup_pk = EVP_PKEY_dup(pkey))
          || !TEST_int_eq(EVP_PKEY_eq(pkey, dup_pk), 1))
          goto err;
  
      temp = ECDSA_size(eckey);
  
      if (!TEST_int_ge(temp, 0)
          || !TEST_ptr(sig = OPENSSL_malloc(sig_len = (size_t)temp))
          /* create a signature */
          || !TEST_true(EVP_DigestSignInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_true(EVP_DigestSign(mctx, sig, &sig_len, tbs, sizeof(tbs)))
          || !TEST_int_le(sig_len, ECDSA_size(eckey))
          || !TEST_true(EVP_MD_CTX_reset(mctx))
          /* negative test, verify with wrong key, 0 return */
          || !TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey_neg))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey_neg))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 0)
          || !TEST_true(EVP_MD_CTX_reset(mctx))
          /* negative test, verify with wrong signature length, -1 return */
          || !TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len - 1, tbs, sizeof(tbs)), -1)
          || !TEST_true(EVP_MD_CTX_reset(mctx))
          /* positive test, verify with correct key, 1 return */
          || !TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 1)
          || !TEST_true(EVP_MD_CTX_reset(mctx)))
          goto err;
  
      /* muck with the message, test it fails with 0 return */
      tbs[0] ^= 1;
      if (!TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 0)
          || !TEST_true(EVP_MD_CTX_reset(mctx)))
          goto err;
      /* un-muck and test it verifies */
      tbs[0] ^= 1;
      if (!TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 1)
          || !TEST_true(EVP_MD_CTX_reset(mctx)))
          goto err;
  
      /*-
       * Muck with the ECDSA signature. The DER encoding is one of:
       * - 30 LL 02 ..
       * - 30 81 LL 02 ..
       *
       * - Sometimes this mucks with the high level DER sequence wrapper:
       *   in that case, DER-parsing of the whole signature should fail.
       *
       * - Sometimes this mucks with the DER-encoding of ECDSA.r:
       *   in that case, DER-parsing of ECDSA.r should fail.
       *
       * - Sometimes this mucks with the DER-encoding of ECDSA.s:
       *   in that case, DER-parsing of ECDSA.s should fail.
       *
       * - Sometimes this mucks with ECDSA.r:
       *   in that case, the signature verification should fail.
       *
       * - Sometimes this mucks with ECDSA.s:
       *   in that case, the signature verification should fail.
       *
       * The usual case is changing the integer value of ECDSA.r or ECDSA.s.
       * Because the ratio of DER overhead to signature bytes is small.
       * So most of the time it will be one of the last two cases.
       *
       * In any case, EVP_PKEY_verify should not return 1 for valid.
       */
      offset = tbs[0] % sig_len;
      dirt = tbs[1] ? tbs[1] : 1;
      sig[offset] ^= dirt;
      if (!TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_ne(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 1)
          || !TEST_true(EVP_MD_CTX_reset(mctx)))
          goto err;
      /* un-muck and test it verifies */
      sig[offset] ^= dirt;
      if (!TEST_true(EVP_DigestVerifyInit(mctx, NULL, NULL, NULL, pkey))
          || (as == EVP_PKEY_SM2 && !set_sm2_id(mctx, pkey))
          || !TEST_int_eq(EVP_DigestVerify(mctx, sig, sig_len, tbs, sizeof(tbs)), 1)
          || !TEST_true(EVP_MD_CTX_reset(mctx)))
          goto err;
  
      ret = 1;
   err:
      EVP_PKEY_free(pkey);
      EVP_PKEY_free(pkey_neg);
      EVP_PKEY_free(dup_pk);
      EVP_MD_CTX_free(mctx);
      OPENSSL_free(sig);
      return ret;
  }
  
  static int test_builtin_as_ec(int n)
  {
      return test_builtin(n, EVP_PKEY_EC);
  }
  
  # ifndef OPENSSL_NO_SM2
  static int test_builtin_as_sm2(int n)
  {
      return test_builtin(n, EVP_PKEY_SM2);
  }
  # endif
  #endif /* OPENSSL_NO_EC */
  
  int setup_tests(void)
  {
  #ifdef OPENSSL_NO_EC
      TEST_note("Elliptic curves are disabled.");
  #else
      fake_rand = fake_rand_start(NULL);
      if (fake_rand == NULL)
          return 0;
  
      /* get a list of all internal curves */
      crv_len = EC_get_builtin_curves(NULL, 0);
      if (!TEST_ptr(curves = OPENSSL_malloc(sizeof(*curves) * crv_len))
          || !TEST_true(EC_get_builtin_curves(curves, crv_len))) {
          fake_rand_finish(fake_rand);
          return 0;
      }
      ADD_ALL_TESTS(test_builtin_as_ec, crv_len);
  # ifndef OPENSSL_NO_SM2
      ADD_ALL_TESTS(test_builtin_as_sm2, crv_len);
  # endif
      ADD_ALL_TESTS(x9_62_tests, OSSL_NELEM(ecdsa_cavs_kats));
  #endif
      return 1;
  }
  
  void cleanup_tests(void)
  {
  #ifndef OPENSSL_NO_EC
      fake_rand_finish(fake_rand);
      OPENSSL_free(curves);
  #endif
  }
  