code: /*
   * Copyright 2020 The OpenSSL Project Authors. 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
   */
  
  #include <string.h>
  #include <openssl/ec.h>
  #include "crypto/ec.h"
  #include "e_os.h" /* strcasecmp required by windows */
  
  typedef struct ec_name2nid_st {
      const char *name;
      int nid;
  } EC_NAME2NID;
  
  static const EC_NAME2NID curve_list[] = {
      /* prime field curves */
      /* secg curves */
      {"secp112r1", NID_secp112r1 },
      {"secp112r2", NID_secp112r2 },
      {"secp128r1", NID_secp128r1 },
      {"secp128r2", NID_secp128r2 },
      {"secp160k1", NID_secp160k1 },
      {"secp160r1", NID_secp160r1 },
      {"secp160r2", NID_secp160r2 },
      {"secp192k1", NID_secp192k1 },
      {"secp224k1", NID_secp224k1 },
      {"secp224r1", NID_secp224r1 },
      {"secp256k1", NID_secp256k1 },
      {"secp384r1", NID_secp384r1 },
      {"secp521r1", NID_secp521r1 },
      /* X9.62 curves */
      {"prime192v1", NID_X9_62_prime192v1 },
      {"prime192v2", NID_X9_62_prime192v2 },
      {"prime192v3", NID_X9_62_prime192v3 },
      {"prime239v1", NID_X9_62_prime239v1 },
      {"prime239v2", NID_X9_62_prime239v2 },
      {"prime239v3", NID_X9_62_prime239v3 },
      {"prime256v1", NID_X9_62_prime256v1 },
      /* characteristic two field curves */
      /* NIST/SECG curves */
      {"sect113r1", NID_sect113r1 },
      {"sect113r2", NID_sect113r2 },
      {"sect131r1", NID_sect131r1 },
      {"sect131r2", NID_sect131r2 },
      {"sect163k1", NID_sect163k1 },
      {"sect163r1", NID_sect163r1 },
      {"sect163r2", NID_sect163r2 },
      {"sect193r1", NID_sect193r1 },
      {"sect193r2", NID_sect193r2 },
      {"sect233k1", NID_sect233k1 },
      {"sect233r1", NID_sect233r1 },
      {"sect239k1", NID_sect239k1 },
      {"sect283k1", NID_sect283k1 },
      {"sect283r1", NID_sect283r1 },
      {"sect409k1", NID_sect409k1 },
      {"sect409r1", NID_sect409r1 },
      {"sect571k1", NID_sect571k1 },
      {"sect571r1", NID_sect571r1 },
      /* X9.62 curves */
      {"c2pnb163v1", NID_X9_62_c2pnb163v1 },
      {"c2pnb163v2", NID_X9_62_c2pnb163v2 },
      {"c2pnb163v3", NID_X9_62_c2pnb163v3 },
      {"c2pnb176v1", NID_X9_62_c2pnb176v1 },
      {"c2tnb191v1", NID_X9_62_c2tnb191v1 },
      {"c2tnb191v2", NID_X9_62_c2tnb191v2 },
      {"c2tnb191v3", NID_X9_62_c2tnb191v3 },
      {"c2pnb208w1", NID_X9_62_c2pnb208w1 },
      {"c2tnb239v1", NID_X9_62_c2tnb239v1 },
      {"c2tnb239v2", NID_X9_62_c2tnb239v2 },
      {"c2tnb239v3", NID_X9_62_c2tnb239v3 },
      {"c2pnb272w1", NID_X9_62_c2pnb272w1 },
      {"c2pnb304w1", NID_X9_62_c2pnb304w1 },
      {"c2tnb359v1", NID_X9_62_c2tnb359v1 },
      {"c2pnb368w1", NID_X9_62_c2pnb368w1 },
      {"c2tnb431r1", NID_X9_62_c2tnb431r1 },
      /*
       * the WAP/WTLS curves [unlike SECG, spec has its own OIDs for curves
       * from X9.62]
       */
      {"wap-wsg-idm-ecid-wtls1", NID_wap_wsg_idm_ecid_wtls1 },
      {"wap-wsg-idm-ecid-wtls3", NID_wap_wsg_idm_ecid_wtls3 },
      {"wap-wsg-idm-ecid-wtls4", NID_wap_wsg_idm_ecid_wtls4 },
      {"wap-wsg-idm-ecid-wtls5", NID_wap_wsg_idm_ecid_wtls5 },
      {"wap-wsg-idm-ecid-wtls6", NID_wap_wsg_idm_ecid_wtls6 },
      {"wap-wsg-idm-ecid-wtls7", NID_wap_wsg_idm_ecid_wtls7 },
      {"wap-wsg-idm-ecid-wtls8", NID_wap_wsg_idm_ecid_wtls8 },
      {"wap-wsg-idm-ecid-wtls9", NID_wap_wsg_idm_ecid_wtls9 },
      {"wap-wsg-idm-ecid-wtls10", NID_wap_wsg_idm_ecid_wtls10 },
      {"wap-wsg-idm-ecid-wtls11", NID_wap_wsg_idm_ecid_wtls11 },
      {"wap-wsg-idm-ecid-wtls12", NID_wap_wsg_idm_ecid_wtls12 },
      /* IPSec curves */
      {"Oakley-EC2N-3", NID_ipsec3 },
      {"Oakley-EC2N-4", NID_ipsec4 },
      /* brainpool curves */
      {"brainpoolP160r1", NID_brainpoolP160r1 },
      {"brainpoolP160t1", NID_brainpoolP160t1 },
      {"brainpoolP192r1", NID_brainpoolP192r1 },
      {"brainpoolP192t1", NID_brainpoolP192t1 },
      {"brainpoolP224r1", NID_brainpoolP224r1 },
      {"brainpoolP224t1", NID_brainpoolP224t1 },
      {"brainpoolP256r1", NID_brainpoolP256r1 },
      {"brainpoolP256t1", NID_brainpoolP256t1 },
      {"brainpoolP320r1", NID_brainpoolP320r1 },
      {"brainpoolP320t1", NID_brainpoolP320t1 },
      {"brainpoolP384r1", NID_brainpoolP384r1 },
      {"brainpoolP384t1", NID_brainpoolP384t1 },
      {"brainpoolP512r1", NID_brainpoolP512r1 },
      {"brainpoolP512t1", NID_brainpoolP512t1 },
      /* SM2 curve */
      {"SM2", NID_sm2 },
  };
  
  const char *ec_curve_nid2name(int nid)
  {
      size_t i;
  
      if (nid <= 0)
          return NULL;
  
      /*
       * TODO(3.0) Figure out if we should try to find the nid with
       * EC_curve_nid2nist() first, i.e. make it a priority to return
       * NIST names if there is one for the NID.  This is related to
       * the TODO comment in ec_curve_name2nid().
       */
  
      for (i = 0; i < OSSL_NELEM(curve_list); i++) {
          if (curve_list[i].nid == nid)
              return curve_list[i].name;
      }
      return NULL;
  }
  
  int ec_curve_name2nid(const char *name)
  {
      size_t i;
      int nid;
  
      if (name != NULL) {
          if ((nid = ec_curve_nist2nid_int(name)) != NID_undef)
              return nid;
  
          for (i = 0; i < OSSL_NELEM(curve_list); i++) {
              if (strcasecmp(curve_list[i].name, name) == 0)
                  return curve_list[i].nid;
          }
      }
  
      return NID_undef;
  }
  
  /* Functions to translate between common NIST curve names and NIDs */
  
  static const EC_NAME2NID nist_curves[] = {
      {"B-163", NID_sect163r2},
      {"B-233", NID_sect233r1},
      {"B-283", NID_sect283r1},
      {"B-409", NID_sect409r1},
      {"B-571", NID_sect571r1},
      {"K-163", NID_sect163k1},
      {"K-233", NID_sect233k1},
      {"K-283", NID_sect283k1},
      {"K-409", NID_sect409k1},
      {"K-571", NID_sect571k1},
      {"P-192", NID_X9_62_prime192v1},
      {"P-224", NID_secp224r1},
      {"P-256", NID_X9_62_prime256v1},
      {"P-384", NID_secp384r1},
      {"P-521", NID_secp521r1}
  };
  
  const char *ec_curve_nid2nist_int(int nid)
  {
      size_t i;
      for (i = 0; i < OSSL_NELEM(nist_curves); i++) {
          if (nist_curves[i].nid == nid)
              return nist_curves[i].name;
      }
      return NULL;
  }
  
  int ec_curve_nist2nid_int(const char *name)
  {
      size_t i;
      for (i = 0; i < OSSL_NELEM(nist_curves); i++) {
          if (strcmp(nist_curves[i].name, name) == 0)
              return nist_curves[i].nid;
      }
      return NID_undef;
  }
  