text: /*
   * Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (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 "ec_lcl.h"
  #include <openssl/err.h>
  #include <openssl/asn1t.h>
  #include <openssl/objects.h>
  #include "internal/nelem.h"
  
  int EC_GROUP_get_basis_type(const EC_GROUP *group)
  {
      int i;
  
      if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
          NID_X9_62_characteristic_two_field)
          /* everything else is currently not supported */
          return 0;
  
      /* Find the last non-zero element of group->poly[] */
      for (i = 0;
           i < (int)OSSL_NELEM(group->poly) && group->poly[i] != 0;
           i++)
          continue;
  
      if (i == 4)
          return NID_X9_62_ppBasis;
      else if (i == 2)
          return NID_X9_62_tpBasis;
      else
          /* everything else is currently not supported */
          return 0;
  }
  
  #ifndef OPENSSL_NO_EC2M
  int EC_GROUP_get_trinomial_basis(const EC_GROUP *group, unsigned int *k)
  {
      if (group == NULL)
          return 0;
  
      if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
          NID_X9_62_characteristic_two_field
          || !((group->poly[0] != 0) && (group->poly[1] != 0)
               && (group->poly[2] == 0))) {
          ECerr(EC_F_EC_GROUP_GET_TRINOMIAL_BASIS,
                ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
          return 0;
      }
  
      if (k)
          *k = group->poly[1];
  
      return 1;
  }
  
  int EC_GROUP_get_pentanomial_basis(const EC_GROUP *group, unsigned int *k1,
                                     unsigned int *k2, unsigned int *k3)
  {
      if (group == NULL)
          return 0;
  
      if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
          NID_X9_62_characteristic_two_field
          || !((group->poly[0] != 0) && (group->poly[1] != 0)
               && (group->poly[2] != 0) && (group->poly[3] != 0)
               && (group->poly[4] == 0))) {
          ECerr(EC_F_EC_GROUP_GET_PENTANOMIAL_BASIS,
                ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
          return 0;
      }
  
      if (k1)
          *k1 = group->poly[3];
      if (k2)
          *k2 = group->poly[2];
      if (k3)
          *k3 = group->poly[1];
  
      return 1;
  }
  #endif
  
  /* some structures needed for the asn1 encoding */
  typedef struct x9_62_pentanomial_st {
      int32_t k1;
      int32_t k2;
      int32_t k3;
  } X9_62_PENTANOMIAL;
  
  typedef struct x9_62_characteristic_two_st {
      int32_t m;
      ASN1_OBJECT *type;
      union {
          char *ptr;
          /* NID_X9_62_onBasis */
          ASN1_NULL *onBasis;
          /* NID_X9_62_tpBasis */
          ASN1_INTEGER *tpBasis;
          /* NID_X9_62_ppBasis */
          X9_62_PENTANOMIAL *ppBasis;
          /* anything else */
          ASN1_TYPE *other;
      } p;
  } X9_62_CHARACTERISTIC_TWO;
  
  typedef struct x9_62_fieldid_st {
      ASN1_OBJECT *fieldType;
      union {
          char *ptr;
          /* NID_X9_62_prime_field */
          ASN1_INTEGER *prime;
          /* NID_X9_62_characteristic_two_field */
          X9_62_CHARACTERISTIC_TWO *char_two;
          /* anything else */
          ASN1_TYPE *other;
      } p;
  } X9_62_FIELDID;
  
  typedef struct x9_62_curve_st {
      ASN1_OCTET_STRING *a;
      ASN1_OCTET_STRING *b;
      ASN1_BIT_STRING *seed;
  } X9_62_CURVE;
  
  struct ec_parameters_st {
      int32_t version;
      X9_62_FIELDID *fieldID;
      X9_62_CURVE *curve;
      ASN1_OCTET_STRING *base;
      ASN1_INTEGER *order;
      ASN1_INTEGER *cofactor;
  } /* ECPARAMETERS */ ;
  
  struct ecpk_parameters_st {
      int type;
      union {
          ASN1_OBJECT *named_curve;
          ECPARAMETERS *parameters;
          ASN1_NULL *implicitlyCA;
      } value;
  } /* ECPKPARAMETERS */ ;
  
  /* SEC1 ECPrivateKey */
  typedef struct ec_privatekey_st {
      int32_t version;
      ASN1_OCTET_STRING *privateKey;
      ECPKPARAMETERS *parameters;
      ASN1_BIT_STRING *publicKey;
  } EC_PRIVATEKEY;
  
  /* the OpenSSL ASN.1 definitions */
  ASN1_SEQUENCE(X9_62_PENTANOMIAL) = {
          ASN1_EMBED(X9_62_PENTANOMIAL, k1, INT32),
          ASN1_EMBED(X9_62_PENTANOMIAL, k2, INT32),
          ASN1_EMBED(X9_62_PENTANOMIAL, k3, INT32)
  } static_ASN1_SEQUENCE_END(X9_62_PENTANOMIAL)
  
  DECLARE_ASN1_ALLOC_FUNCTIONS(X9_62_PENTANOMIAL)
  IMPLEMENT_ASN1_ALLOC_FUNCTIONS(X9_62_PENTANOMIAL)
  
  ASN1_ADB_TEMPLATE(char_two_def) = ASN1_SIMPLE(X9_62_CHARACTERISTIC_TWO, p.other, ASN1_ANY);
  
  ASN1_ADB(X9_62_CHARACTERISTIC_TWO) = {
          ADB_ENTRY(NID_X9_62_onBasis, ASN1_SIMPLE(X9_62_CHARACTERISTIC_TWO, p.onBasis, ASN1_NULL)),
          ADB_ENTRY(NID_X9_62_tpBasis, ASN1_SIMPLE(X9_62_CHARACTERISTIC_TWO, p.tpBasis, ASN1_INTEGER)),
          ADB_ENTRY(NID_X9_62_ppBasis, ASN1_SIMPLE(X9_62_CHARACTERISTIC_TWO, p.ppBasis, X9_62_PENTANOMIAL))
  } ASN1_ADB_END(X9_62_CHARACTERISTIC_TWO, 0, type, 0, &char_two_def_tt, NULL);
  
  ASN1_SEQUENCE(X9_62_CHARACTERISTIC_TWO) = {
          ASN1_EMBED(X9_62_CHARACTERISTIC_TWO, m, INT32),
          ASN1_SIMPLE(X9_62_CHARACTERISTIC_TWO, type, ASN1_OBJECT),
          ASN1_ADB_OBJECT(X9_62_CHARACTERISTIC_TWO)
  } static_ASN1_SEQUENCE_END(X9_62_CHARACTERISTIC_TWO)
  
  DECLARE_ASN1_ALLOC_FUNCTIONS(X9_62_CHARACTERISTIC_TWO)
  IMPLEMENT_ASN1_ALLOC_FUNCTIONS(X9_62_CHARACTERISTIC_TWO)
  
  ASN1_ADB_TEMPLATE(fieldID_def) = ASN1_SIMPLE(X9_62_FIELDID, p.other, ASN1_ANY);
  
  ASN1_ADB(X9_62_FIELDID) = {
          ADB_ENTRY(NID_X9_62_prime_field, ASN1_SIMPLE(X9_62_FIELDID, p.prime, ASN1_INTEGER)),
          ADB_ENTRY(NID_X9_62_characteristic_two_field, ASN1_SIMPLE(X9_62_FIELDID, p.char_two, X9_62_CHARACTERISTIC_TWO))
  } ASN1_ADB_END(X9_62_FIELDID, 0, fieldType, 0, &fieldID_def_tt, NULL);
  
  ASN1_SEQUENCE(X9_62_FIELDID) = {
          ASN1_SIMPLE(X9_62_FIELDID, fieldType, ASN1_OBJECT),
          ASN1_ADB_OBJECT(X9_62_FIELDID)
  } static_ASN1_SEQUENCE_END(X9_62_FIELDID)
  
  ASN1_SEQUENCE(X9_62_CURVE) = {
          ASN1_SIMPLE(X9_62_CURVE, a, ASN1_OCTET_STRING),
          ASN1_SIMPLE(X9_62_CURVE, b, ASN1_OCTET_STRING),
          ASN1_OPT(X9_62_CURVE, seed, ASN1_BIT_STRING)
  } static_ASN1_SEQUENCE_END(X9_62_CURVE)
  
  ASN1_SEQUENCE(ECPARAMETERS) = {
          ASN1_EMBED(ECPARAMETERS, version, INT32),
          ASN1_SIMPLE(ECPARAMETERS, fieldID, X9_62_FIELDID),
          ASN1_SIMPLE(ECPARAMETERS, curve, X9_62_CURVE),
          ASN1_SIMPLE(ECPARAMETERS, base, ASN1_OCTET_STRING),
          ASN1_SIMPLE(ECPARAMETERS, order, ASN1_INTEGER),
          ASN1_OPT(ECPARAMETERS, cofactor, ASN1_INTEGER)
  } ASN1_SEQUENCE_END(ECPARAMETERS)
  
  DECLARE_ASN1_ALLOC_FUNCTIONS(ECPARAMETERS)
  IMPLEMENT_ASN1_ALLOC_FUNCTIONS(ECPARAMETERS)
  
  ASN1_CHOICE(ECPKPARAMETERS) = {
          ASN1_SIMPLE(ECPKPARAMETERS, value.named_curve, ASN1_OBJECT),
          ASN1_SIMPLE(ECPKPARAMETERS, value.parameters, ECPARAMETERS),
          ASN1_SIMPLE(ECPKPARAMETERS, value.implicitlyCA, ASN1_NULL)
  } ASN1_CHOICE_END(ECPKPARAMETERS)
  
  DECLARE_ASN1_FUNCTIONS_const(ECPKPARAMETERS)
  DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECPKPARAMETERS, ECPKPARAMETERS)
  IMPLEMENT_ASN1_FUNCTIONS_const(ECPKPARAMETERS)
  
  ASN1_SEQUENCE(EC_PRIVATEKEY) = {
          ASN1_EMBED(EC_PRIVATEKEY, version, INT32),
          ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
          ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
          ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
  } static_ASN1_SEQUENCE_END(EC_PRIVATEKEY)
  
  DECLARE_ASN1_FUNCTIONS_const(EC_PRIVATEKEY)
  DECLARE_ASN1_ENCODE_FUNCTIONS_const(EC_PRIVATEKEY, EC_PRIVATEKEY)
  IMPLEMENT_ASN1_FUNCTIONS_const(EC_PRIVATEKEY)
  
  /* some declarations of internal function */
  
  /* ec_asn1_group2field() sets the values in a X9_62_FIELDID object */
  static int ec_asn1_group2fieldid(const EC_GROUP *, X9_62_FIELDID *);
  /* ec_asn1_group2curve() sets the values in a X9_62_CURVE object */
  static int ec_asn1_group2curve(const EC_GROUP *, X9_62_CURVE *);
  
  /* the function definitions */
  
  static int ec_asn1_group2fieldid(const EC_GROUP *group, X9_62_FIELDID *field)
  {
      int ok = 0, nid;
      BIGNUM *tmp = NULL;
  
      if (group == NULL || field == NULL)
          return 0;
  
      /* clear the old values (if necessary) */
      ASN1_OBJECT_free(field->fieldType);
      ASN1_TYPE_free(field->p.other);
  
      nid = EC_METHOD_get_field_type(EC_GROUP_method_of(group));
      /* set OID for the field */
      if ((field->fieldType = OBJ_nid2obj(nid)) == NULL) {
          ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_OBJ_LIB);
          goto err;
      }
  
      if (nid == NID_X9_62_prime_field) {
          if ((tmp = BN_new()) == NULL) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_MALLOC_FAILURE);
              goto err;
          }
          /* the parameters are specified by the prime number p */
          if (!EC_GROUP_get_curve_GFp(group, tmp, NULL, NULL, NULL)) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_EC_LIB);
              goto err;
          }
          /* set the prime number */
          field->p.prime = BN_to_ASN1_INTEGER(tmp, NULL);
          if (field->p.prime == NULL) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_ASN1_LIB);
              goto err;
          }
      } else if (nid == NID_X9_62_characteristic_two_field)
  #ifdef OPENSSL_NO_EC2M
      {
          ECerr(EC_F_EC_ASN1_GROUP2FIELDID, EC_R_GF2M_NOT_SUPPORTED);
          goto err;
      }
  #else
      {
          int field_type;
          X9_62_CHARACTERISTIC_TWO *char_two;
  
          field->p.char_two = X9_62_CHARACTERISTIC_TWO_new();
          char_two = field->p.char_two;
  
          if (char_two == NULL) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_MALLOC_FAILURE);
              goto err;
          }
  
          char_two->m = (long)EC_GROUP_get_degree(group);
  
          field_type = EC_GROUP_get_basis_type(group);
  
          if (field_type == 0) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_EC_LIB);
              goto err;
          }
          /* set base type OID */
          if ((char_two->type = OBJ_nid2obj(field_type)) == NULL) {
              ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_OBJ_LIB);
              goto err;
          }
  
          if (field_type == NID_X9_62_tpBasis) {
              unsigned int k;
  
              if (!EC_GROUP_get_trinomial_basis(group, &k))
                  goto err;
  
              char_two->p.tpBasis = ASN1_INTEGER_new();
              if (char_two->p.tpBasis == NULL) {
                  ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
              if (!ASN1_INTEGER_set(char_two->p.tpBasis, (long)k)) {
                  ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_ASN1_LIB);
                  goto err;
              }
          } else if (field_type == NID_X9_62_ppBasis) {
              unsigned int k1, k2, k3;
  
              if (!EC_GROUP_get_pentanomial_basis(group, &k1, &k2, &k3))
                  goto err;
  
              char_two->p.ppBasis = X9_62_PENTANOMIAL_new();
              if (char_two->p.ppBasis == NULL) {
                  ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
  
              /* set k? values */
              char_two->p.ppBasis->k1 = (long)k1;
              char_two->p.ppBasis->k2 = (long)k2;
              char_two->p.ppBasis->k3 = (long)k3;
          } else {                /* field_type == NID_X9_62_onBasis */
  
              /* for ONB the parameters are (asn1) NULL */
              char_two->p.onBasis = ASN1_NULL_new();
              if (char_two->p.onBasis == NULL) {
                  ECerr(EC_F_EC_ASN1_GROUP2FIELDID, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
          }
      }
  #endif
      else {
          ECerr(EC_F_EC_ASN1_GROUP2FIELDID, EC_R_UNSUPPORTED_FIELD);
          goto err;
      }
  
      ok = 1;
  
   err:
      BN_free(tmp);
      return ok;
  }
  
  static int ec_asn1_group2curve(const EC_GROUP *group, X9_62_CURVE *curve)
  {
      int ok = 0, nid;
      BIGNUM *tmp_1 = NULL, *tmp_2 = NULL;
      unsigned char *a_buf = NULL, *b_buf = NULL;
      size_t len;
  
      if (!group || !curve || !curve->a || !curve->b)
          return 0;
  
      if ((tmp_1 = BN_new()) == NULL || (tmp_2 = BN_new()) == NULL) {
          ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      nid = EC_METHOD_get_field_type(EC_GROUP_method_of(group));
  
      /* get a and b */
      if (nid == NID_X9_62_prime_field) {
          if (!EC_GROUP_get_curve_GFp(group, NULL, tmp_1, tmp_2, NULL)) {
              ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_EC_LIB);
              goto err;
          }
      }
  #ifndef OPENSSL_NO_EC2M
      else {                      /* nid == NID_X9_62_characteristic_two_field */
  
          if (!EC_GROUP_get_curve_GF2m(group, NULL, tmp_1, tmp_2, NULL)) {
              ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_EC_LIB);
              goto err;
          }
      }
  #endif
      /*
       * Per SEC 1, the curve coefficients must be padded up to size. See C.2's
       * definition of Curve, C.1's definition of FieldElement, and 2.3.5's
       * definition of how to encode the field elements.
       */
      len = ((size_t)EC_GROUP_get_degree(group) + 7) / 8;
      if ((a_buf = OPENSSL_malloc(len)) == NULL
          || (b_buf = OPENSSL_malloc(len)) == NULL) {
          ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      if (BN_bn2binpad(tmp_1, a_buf, len) < 0
          || BN_bn2binpad(tmp_2, b_buf, len) < 0) {
          ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_BN_LIB);
          goto err;
      }
  
      /* set a and b */
      if (!ASN1_OCTET_STRING_set(curve->a, a_buf, len)
          || !ASN1_OCTET_STRING_set(curve->b, b_buf, len)) {
          ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_ASN1_LIB);
          goto err;
      }
  
      /* set the seed (optional) */
      if (group->seed) {
          if (!curve->seed)
              if ((curve->seed = ASN1_BIT_STRING_new()) == NULL) {
                  ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
          curve->seed->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
          curve->seed->flags |= ASN1_STRING_FLAG_BITS_LEFT;
          if (!ASN1_BIT_STRING_set(curve->seed, group->seed,
                                   (int)group->seed_len)) {
              ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_ASN1_LIB);
              goto err;
          }
      } else {
          ASN1_BIT_STRING_free(curve->seed);
          curve->seed = NULL;
      }
  
      ok = 1;
  
   err:
      OPENSSL_free(a_buf);
      OPENSSL_free(b_buf);
      BN_free(tmp_1);
      BN_free(tmp_2);
      return ok;
  }
  
  ECPARAMETERS *EC_GROUP_get_ecparameters(const EC_GROUP *group,
                                                 ECPARAMETERS *params)
  {
      size_t len = 0;
      ECPARAMETERS *ret = NULL;
      const BIGNUM *tmp;
      unsigned char *buffer = NULL;
      const EC_POINT *point = NULL;
      point_conversion_form_t form;
  
      if (params == NULL) {
          if ((ret = ECPARAMETERS_new()) == NULL) {
              ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_MALLOC_FAILURE);
              goto err;
          }
      } else
          ret = params;
  
      /* set the version (always one) */
      ret->version = (long)0x1;
  
      /* set the fieldID */
      if (!ec_asn1_group2fieldid(group, ret->fieldID)) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
  
      /* set the curve */
      if (!ec_asn1_group2curve(group, ret->curve)) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
  
      /* set the base point */
      if ((point = EC_GROUP_get0_generator(group)) == NULL) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, EC_R_UNDEFINED_GENERATOR);
          goto err;
      }
  
      form = EC_GROUP_get_point_conversion_form(group);
  
      len = EC_POINT_point2buf(group, point, form, &buffer, NULL);
      if (len == 0) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
      if (ret->base == NULL && (ret->base = ASN1_OCTET_STRING_new()) == NULL) {
          OPENSSL_free(buffer);
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      ASN1_STRING_set0(ret->base, buffer, len);
  
      /* set the order */
      tmp = EC_GROUP_get0_order(group);
      if (tmp == NULL) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
      ret->order = BN_to_ASN1_INTEGER(tmp, ret->order);
      if (ret->order == NULL) {
          ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_ASN1_LIB);
          goto err;
      }
  
      /* set the cofactor (optional) */
      tmp = EC_GROUP_get0_cofactor(group);
      if (tmp != NULL) {
          ret->cofactor = BN_to_ASN1_INTEGER(tmp, ret->cofactor);
          if (ret->cofactor == NULL) {
              ECerr(EC_F_EC_GROUP_GET_ECPARAMETERS, ERR_R_ASN1_LIB);
              goto err;
          }
      }
  
      return ret;
  
   err:
      if (params == NULL)
          ECPARAMETERS_free(ret);
      return NULL;
  }
  
  ECPKPARAMETERS *EC_GROUP_get_ecpkparameters(const EC_GROUP *group,
                                              ECPKPARAMETERS *params)
  {
      int ok = 1, tmp;
      ECPKPARAMETERS *ret = params;
  
      if (ret == NULL) {
          if ((ret = ECPKPARAMETERS_new()) == NULL) {
              ECerr(EC_F_EC_GROUP_GET_ECPKPARAMETERS, ERR_R_MALLOC_FAILURE);
              return NULL;
          }
      } else {
          if (ret->type == 0)
              ASN1_OBJECT_free(ret->value.named_curve);
          else if (ret->type == 1 && ret->value.parameters)
              ECPARAMETERS_free(ret->value.parameters);
      }
  
      if (EC_GROUP_get_asn1_flag(group)) {
          /*
           * use the asn1 OID to describe the elliptic curve parameters
           */
          tmp = EC_GROUP_get_curve_name(group);
          if (tmp) {
              ret->type = 0;
              if ((ret->value.named_curve = OBJ_nid2obj(tmp)) == NULL)
                  ok = 0;
          } else
              /* we don't know the nid => ERROR */
              ok = 0;
      } else {
          /* use the ECPARAMETERS structure */
          ret->type = 1;
          if ((ret->value.parameters =
               EC_GROUP_get_ecparameters(group, NULL)) == NULL)
              ok = 0;
      }
  
      if (!ok) {
          ECPKPARAMETERS_free(ret);
          return NULL;
      }
      return ret;
  }
  
  EC_GROUP *EC_GROUP_new_from_ecparameters(const ECPARAMETERS *params)
  {
      int ok = 0, tmp;
      EC_GROUP *ret = NULL;
      BIGNUM *p = NULL, *a = NULL, *b = NULL;
      EC_POINT *point = NULL;
      long field_bits;
  
      if (!params->fieldID || !params->fieldID->fieldType ||
          !params->fieldID->p.ptr) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
          goto err;
      }
  
      /*
       * Now extract the curve parameters a and b. Note that, although SEC 1
       * specifies the length of their encodings, historical versions of OpenSSL
       * encoded them incorrectly, so we must accept any length for backwards
       * compatibility.
       */
      if (!params->curve || !params->curve->a ||
          !params->curve->a->data || !params->curve->b ||
          !params->curve->b->data) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
          goto err;
      }
      a = BN_bin2bn(params->curve->a->data, params->curve->a->length, NULL);
      if (a == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_BN_LIB);
          goto err;
      }
      b = BN_bin2bn(params->curve->b->data, params->curve->b->length, NULL);
      if (b == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_BN_LIB);
          goto err;
      }
  
      /* get the field parameters */
      tmp = OBJ_obj2nid(params->fieldID->fieldType);
      if (tmp == NID_X9_62_characteristic_two_field)
  #ifdef OPENSSL_NO_EC2M
      {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_GF2M_NOT_SUPPORTED);
          goto err;
      }
  #else
      {
          X9_62_CHARACTERISTIC_TWO *char_two;
  
          char_two = params->fieldID->p.char_two;
  
          field_bits = char_two->m;
          if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_FIELD_TOO_LARGE);
              goto err;
          }
  
          if ((p = BN_new()) == NULL) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_MALLOC_FAILURE);
              goto err;
          }
  
          /* get the base type */
          tmp = OBJ_obj2nid(char_two->type);
  
          if (tmp == NID_X9_62_tpBasis) {
              long tmp_long;
  
              if (!char_two->p.tpBasis) {
                  ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
                  goto err;
              }
  
              tmp_long = ASN1_INTEGER_get(char_two->p.tpBasis);
  
              if (!(char_two->m > tmp_long && tmp_long > 0)) {
                  ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS,
                        EC_R_INVALID_TRINOMIAL_BASIS);
                  goto err;
              }
  
              /* create the polynomial */
              if (!BN_set_bit(p, (int)char_two->m))
                  goto err;
              if (!BN_set_bit(p, (int)tmp_long))
                  goto err;
              if (!BN_set_bit(p, 0))
                  goto err;
          } else if (tmp == NID_X9_62_ppBasis) {
              X9_62_PENTANOMIAL *penta;
  
              penta = char_two->p.ppBasis;
              if (!penta) {
                  ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
                  goto err;
              }
  
              if (!
                  (char_two->m > penta->k3 && penta->k3 > penta->k2
                   && penta->k2 > penta->k1 && penta->k1 > 0)) {
                  ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS,
                        EC_R_INVALID_PENTANOMIAL_BASIS);
                  goto err;
              }
  
              /* create the polynomial */
              if (!BN_set_bit(p, (int)char_two->m))
                  goto err;
              if (!BN_set_bit(p, (int)penta->k1))
                  goto err;
              if (!BN_set_bit(p, (int)penta->k2))
                  goto err;
              if (!BN_set_bit(p, (int)penta->k3))
                  goto err;
              if (!BN_set_bit(p, 0))
                  goto err;
          } else if (tmp == NID_X9_62_onBasis) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_NOT_IMPLEMENTED);
              goto err;
          } else {                /* error */
  
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
              goto err;
          }
  
          /* create the EC_GROUP structure */
          ret = EC_GROUP_new_curve_GF2m(p, a, b, NULL);
      }
  #endif
      else if (tmp == NID_X9_62_prime_field) {
          /* we have a curve over a prime field */
          /* extract the prime number */
          if (!params->fieldID->p.prime) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
              goto err;
          }
          p = ASN1_INTEGER_to_BN(params->fieldID->p.prime, NULL);
          if (p == NULL) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_ASN1_LIB);
              goto err;
          }
  
          if (BN_is_negative(p) || BN_is_zero(p)) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_INVALID_FIELD);
              goto err;
          }
  
          field_bits = BN_num_bits(p);
          if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_FIELD_TOO_LARGE);
              goto err;
          }
  
          /* create the EC_GROUP structure */
          ret = EC_GROUP_new_curve_GFp(p, a, b, NULL);
      } else {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_INVALID_FIELD);
          goto err;
      }
  
      if (ret == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
  
      /* extract seed (optional) */
      if (params->curve->seed != NULL) {
          OPENSSL_free(ret->seed);
          if ((ret->seed = OPENSSL_malloc(params->curve->seed->length)) == NULL) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_MALLOC_FAILURE);
              goto err;
          }
          memcpy(ret->seed, params->curve->seed->data,
                 params->curve->seed->length);
          ret->seed_len = params->curve->seed->length;
      }
  
      if (!params->order || !params->base || !params->base->data) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
          goto err;
      }
  
      if ((point = EC_POINT_new(ret)) == NULL)
          goto err;
  
      /* set the point conversion form */
      EC_GROUP_set_point_conversion_form(ret, (point_conversion_form_t)
                                         (params->base->data[0] & ~0x01));
  
      /* extract the ec point */
      if (!EC_POINT_oct2point(ret, point, params->base->data,
                              params->base->length, NULL)) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
  
      /* extract the order */
      if ((a = ASN1_INTEGER_to_BN(params->order, a)) == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_ASN1_LIB);
          goto err;
      }
      if (BN_is_negative(a) || BN_is_zero(a)) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_INVALID_GROUP_ORDER);
          goto err;
      }
      if (BN_num_bits(a) > (int)field_bits + 1) { /* Hasse bound */
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_INVALID_GROUP_ORDER);
          goto err;
      }
  
      /* extract the cofactor (optional) */
      if (params->cofactor == NULL) {
          BN_free(b);
          b = NULL;
      } else if ((b = ASN1_INTEGER_to_BN(params->cofactor, b)) == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_ASN1_LIB);
          goto err;
      }
      /* set the generator, order and cofactor (if present) */
      if (!EC_GROUP_set_generator(ret, point, a, b)) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, ERR_R_EC_LIB);
          goto err;
      }
  
      ok = 1;
  
   err:
      if (!ok) {
          EC_GROUP_clear_free(ret);
          ret = NULL;
      }
  
      BN_free(p);
      BN_free(a);
      BN_free(b);
      EC_POINT_free(point);
      return ret;
  }
  
  EC_GROUP *EC_GROUP_new_from_ecpkparameters(const ECPKPARAMETERS *params)
  {
      EC_GROUP *ret = NULL;
      int tmp = 0;
  
      if (params == NULL) {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPKPARAMETERS, EC_R_MISSING_PARAMETERS);
          return NULL;
      }
  
      if (params->type == 0) {    /* the curve is given by an OID */
          tmp = OBJ_obj2nid(params->value.named_curve);
          if ((ret = EC_GROUP_new_by_curve_name(tmp)) == NULL) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPKPARAMETERS,
                    EC_R_EC_GROUP_NEW_BY_NAME_FAILURE);
              return NULL;
          }
          EC_GROUP_set_asn1_flag(ret, OPENSSL_EC_NAMED_CURVE);
      } else if (params->type == 1) { /* the parameters are given by a
                                       * ECPARAMETERS structure */
          ret = EC_GROUP_new_from_ecparameters(params->value.parameters);
          if (!ret) {
              ECerr(EC_F_EC_GROUP_NEW_FROM_ECPKPARAMETERS, ERR_R_EC_LIB);
              return NULL;
          }
          EC_GROUP_set_asn1_flag(ret, OPENSSL_EC_EXPLICIT_CURVE);
      } else if (params->type == 2) { /* implicitlyCA */
          return NULL;
      } else {
          ECerr(EC_F_EC_GROUP_NEW_FROM_ECPKPARAMETERS, EC_R_ASN1_ERROR);
          return NULL;
      }
  
      return ret;
  }
  
  /* EC_GROUP <-> DER encoding of ECPKPARAMETERS */
  
  EC_GROUP *d2i_ECPKParameters(EC_GROUP **a, const unsigned char **in, long len)
  {
      EC_GROUP *group = NULL;
      ECPKPARAMETERS *params = NULL;
      const unsigned char *p = *in;
  
      if ((params = d2i_ECPKPARAMETERS(NULL, &p, len)) == NULL) {
          ECerr(EC_F_D2I_ECPKPARAMETERS, EC_R_D2I_ECPKPARAMETERS_FAILURE);
          ECPKPARAMETERS_free(params);
          return NULL;
      }
  
      if ((group = EC_GROUP_new_from_ecpkparameters(params)) == NULL) {
          ECerr(EC_F_D2I_ECPKPARAMETERS, EC_R_PKPARAMETERS2GROUP_FAILURE);
          ECPKPARAMETERS_free(params);
          return NULL;
      }
  
      if (a) {
          EC_GROUP_clear_free(*a);
          *a = group;
      }
  
      ECPKPARAMETERS_free(params);
      *in = p;
      return group;
  }
  
  int i2d_ECPKParameters(const EC_GROUP *a, unsigned char **out)
  {
      int ret = 0;
      ECPKPARAMETERS *tmp = EC_GROUP_get_ecpkparameters(a, NULL);
      if (tmp == NULL) {
          ECerr(EC_F_I2D_ECPKPARAMETERS, EC_R_GROUP2PKPARAMETERS_FAILURE);
          return 0;
      }
      if ((ret = i2d_ECPKPARAMETERS(tmp, out)) == 0) {
          ECerr(EC_F_I2D_ECPKPARAMETERS, EC_R_I2D_ECPKPARAMETERS_FAILURE);
          ECPKPARAMETERS_free(tmp);
          return 0;
      }
      ECPKPARAMETERS_free(tmp);
      return ret;
  }
  
  /* some EC_KEY functions */
  
  EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len)
  {
      EC_KEY *ret = NULL;
      EC_PRIVATEKEY *priv_key = NULL;
      const unsigned char *p = *in;
  
      if ((priv_key = d2i_EC_PRIVATEKEY(NULL, &p, len)) == NULL) {
          ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
          return NULL;
      }
  
      if (a == NULL || *a == NULL) {
          if ((ret = EC_KEY_new()) == NULL) {
              ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_MALLOC_FAILURE);
              goto err;
          }
      } else
          ret = *a;
  
      if (priv_key->parameters) {
          EC_GROUP_clear_free(ret->group);
          ret->group = EC_GROUP_new_from_ecpkparameters(priv_key->parameters);
      }
  
      if (ret->group == NULL) {
          ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
          goto err;
      }
  
      ret->version = priv_key->version;
  
      if (priv_key->privateKey) {
          ASN1_OCTET_STRING *pkey = priv_key->privateKey;
          if (EC_KEY_oct2priv(ret, ASN1_STRING_get0_data(pkey),
                              ASN1_STRING_length(pkey)) == 0)
              goto err;
      } else {
          ECerr(EC_F_D2I_ECPRIVATEKEY, EC_R_MISSING_PRIVATE_KEY);
          goto err;
      }
  
      EC_POINT_clear_free(ret->pub_key);
      ret->pub_key = EC_POINT_new(ret->group);
      if (ret->pub_key == NULL) {
          ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
          goto err;
      }
  
      if (priv_key->publicKey) {
          const unsigned char *pub_oct;
          int pub_oct_len;
  
          pub_oct = ASN1_STRING_get0_data(priv_key->publicKey);
          pub_oct_len = ASN1_STRING_length(priv_key->publicKey);
          if (!EC_KEY_oct2key(ret, pub_oct, pub_oct_len, NULL)) {
              ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
              goto err;
          }
      } else {
          if (ret->group->meth->keygenpub == NULL
              || ret->group->meth->keygenpub(ret) == 0)
                  goto err;
          /* Remember the original private-key-only encoding. */
          ret->enc_flag |= EC_PKEY_NO_PUBKEY;
      }
  
      if (a)
          *a = ret;
      EC_PRIVATEKEY_free(priv_key);
      *in = p;
      return ret;
  
   err:
      if (a == NULL || *a != ret)
          EC_KEY_free(ret);
      EC_PRIVATEKEY_free(priv_key);
      return NULL;
  }
  
  int i2d_ECPrivateKey(EC_KEY *a, unsigned char **out)
  {
      int ret = 0, ok = 0;
      unsigned char *priv= NULL, *pub= NULL;
      size_t privlen = 0, publen = 0;
  
      EC_PRIVATEKEY *priv_key = NULL;
  
      if (a == NULL || a->group == NULL ||
          (!(a->enc_flag & EC_PKEY_NO_PUBKEY) && a->pub_key == NULL)) {
          ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_PASSED_NULL_PARAMETER);
          goto err;
      }
  
      if ((priv_key = EC_PRIVATEKEY_new()) == NULL) {
          ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      priv_key->version = a->version;
  
      privlen = EC_KEY_priv2buf(a, &priv);
  
      if (privlen == 0) {
          ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_EC_LIB);
          goto err;
      }
  
      ASN1_STRING_set0(priv_key->privateKey, priv, privlen);
      priv = NULL;
  
      if (!(a->enc_flag & EC_PKEY_NO_PARAMETERS)) {
          if ((priv_key->parameters =
               EC_GROUP_get_ecpkparameters(a->group,
                                          priv_key->parameters)) == NULL) {
              ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_EC_LIB);
              goto err;
          }
      }
  
      if (!(a->enc_flag & EC_PKEY_NO_PUBKEY)) {
          priv_key->publicKey = ASN1_BIT_STRING_new();
          if (priv_key->publicKey == NULL) {
              ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_MALLOC_FAILURE);
              goto err;
          }
  
          publen = EC_KEY_key2buf(a, a->conv_form, &pub, NULL);
  
          if (publen == 0) {
              ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_EC_LIB);
              goto err;
          }
  
          priv_key->publicKey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
          priv_key->publicKey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
          ASN1_STRING_set0(priv_key->publicKey, pub, publen);
          pub = NULL;
      }
  
      if ((ret = i2d_EC_PRIVATEKEY(priv_key, out)) == 0) {
          ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_EC_LIB);
          goto err;
      }
      ok = 1;
   err:
      OPENSSL_clear_free(priv, privlen);
      OPENSSL_free(pub);
      EC_PRIVATEKEY_free(priv_key);
      return (ok ? ret : 0);
  }
  
  int i2d_ECParameters(EC_KEY *a, unsigned char **out)
  {
      if (a == NULL) {
          ECerr(EC_F_I2D_ECPARAMETERS, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
      return i2d_ECPKParameters(a->group, out);
  }
  
  EC_KEY *d2i_ECParameters(EC_KEY **a, const unsigned char **in, long len)
  {
      EC_KEY *ret;
  
      if (in == NULL || *in == NULL) {
          ECerr(EC_F_D2I_ECPARAMETERS, ERR_R_PASSED_NULL_PARAMETER);
          return NULL;
      }
  
      if (a == NULL || *a == NULL) {
          if ((ret = EC_KEY_new()) == NULL) {
              ECerr(EC_F_D2I_ECPARAMETERS, ERR_R_MALLOC_FAILURE);
              return NULL;
          }
      } else
          ret = *a;
  
      if (!d2i_ECPKParameters(&ret->group, in, len)) {
          ECerr(EC_F_D2I_ECPARAMETERS, ERR_R_EC_LIB);
          if (a == NULL || *a != ret)
               EC_KEY_free(ret);
          return NULL;
      }
  
      if (a)
          *a = ret;
  
      return ret;
  }
  
  EC_KEY *o2i_ECPublicKey(EC_KEY **a, const unsigned char **in, long len)
  {
      EC_KEY *ret = NULL;
  
      if (a == NULL || (*a) == NULL || (*a)->group == NULL) {
          /*
           * sorry, but a EC_GROUP-structure is necessary to set the public key
           */
          ECerr(EC_F_O2I_ECPUBLICKEY, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
      ret = *a;
      if (!EC_KEY_oct2key(ret, *in, len, NULL)) {
          ECerr(EC_F_O2I_ECPUBLICKEY, ERR_R_EC_LIB);
          return 0;
      }
      *in += len;
      return ret;
  }
  
  int i2o_ECPublicKey(const EC_KEY *a, unsigned char **out)
  {
      size_t buf_len = 0;
      int new_buffer = 0;
  
      if (a == NULL) {
          ECerr(EC_F_I2O_ECPUBLICKEY, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      buf_len = EC_POINT_point2oct(a->group, a->pub_key,
                                   a->conv_form, NULL, 0, NULL);
  
      if (out == NULL || buf_len == 0)
          /* out == NULL => just return the length of the octet string */
          return buf_len;
  
      if (*out == NULL) {
          if ((*out = OPENSSL_malloc(buf_len)) == NULL) {
              ECerr(EC_F_I2O_ECPUBLICKEY, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          new_buffer = 1;
      }
      if (!EC_POINT_point2oct(a->group, a->pub_key, a->conv_form,
                              *out, buf_len, NULL)) {
          ECerr(EC_F_I2O_ECPUBLICKEY, ERR_R_EC_LIB);
          if (new_buffer) {
              OPENSSL_free(*out);
              *out = NULL;
          }
          return 0;
      }
      if (!new_buffer)
          *out += buf_len;
      return buf_len;
  }
  
  ASN1_SEQUENCE(ECDSA_SIG) = {
          ASN1_SIMPLE(ECDSA_SIG, r, CBIGNUM),
          ASN1_SIMPLE(ECDSA_SIG, s, CBIGNUM)
  } static_ASN1_SEQUENCE_END(ECDSA_SIG)
  
  DECLARE_ASN1_FUNCTIONS_const(ECDSA_SIG)
  DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECDSA_SIG, ECDSA_SIG)
  IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(ECDSA_SIG, ECDSA_SIG, ECDSA_SIG)
  
  ECDSA_SIG *ECDSA_SIG_new(void)
  {
      ECDSA_SIG *sig = OPENSSL_zalloc(sizeof(*sig));
      if (sig == NULL)
          ECerr(EC_F_ECDSA_SIG_NEW, ERR_R_MALLOC_FAILURE);
      return sig;
  }
  
  void ECDSA_SIG_free(ECDSA_SIG *sig)
  {
      if (sig == NULL)
          return;
      BN_clear_free(sig->r);
      BN_clear_free(sig->s);
      OPENSSL_free(sig);
  }
  
  void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
  {
      if (pr != NULL)
          *pr = sig->r;
      if (ps != NULL)
          *ps = sig->s;
  }
  
  const BIGNUM *ECDSA_SIG_get0_r(const ECDSA_SIG *sig)
  {
      return sig->r;
  }
  
  const BIGNUM *ECDSA_SIG_get0_s(const ECDSA_SIG *sig)
  {
      return sig->s;
  }
  
  int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s)
  {
      if (r == NULL || s == NULL)
          return 0;
      BN_clear_free(sig->r);
      BN_clear_free(sig->s);
      sig->r = r;
      sig->s = s;
      return 1;
  }
  
  int ECDSA_size(const EC_KEY *r)
  {
      int ret, i;
      ASN1_INTEGER bs;
      unsigned char buf[4];
      const EC_GROUP *group;
  
      if (r == NULL)
          return 0;
      group = EC_KEY_get0_group(r);
      if (group == NULL)
          return 0;
  
      i = EC_GROUP_order_bits(group);
      if (i == 0)
          return 0;
      bs.length = (i + 7) / 8;
      bs.data = buf;
      bs.type = V_ASN1_INTEGER;
      /* If the top bit is set the asn1 encoding is 1 larger. */
      buf[0] = 0xff;
  
      i = i2d_ASN1_INTEGER(&bs, NULL);
      i += i;                     /* r and s */
      ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
      return ret;
  }
  