text: /*
   * RELIC is an Efficient LIbrary for Cryptography
   * Copyright (c) 2009 RELIC Authors
   *
   * This file is part of RELIC. RELIC is legal property of its developers,
   * whose names are not listed here. Please refer to the COPYRIGHT file
   * for contact information.
   *
   * RELIC is free software; you can redistribute it and/or modify it under the
   * terms of the version 2.1 (or later) of the GNU Lesser General Public License
   * as published by the Free Software Foundation; or version 2.0 of the Apache
   * License as published by the Apache Software Foundation. See the LICENSE files
   * for more details.
   *
   * RELIC is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the LICENSE files for more details.
   *
   * You should have received a copy of the GNU Lesser General Public or the
   * Apache License along with RELIC. If not, see <https://www.gnu.org/licenses/>
   * or <https://www.apache.org/licenses/>.
   */
  
  /**
   * @file
   *
   * Implementation of point normalization on prime elliptic curves.
   *
   * @ingroup ep
   */
  
  #include "relic_core.h"
  
  /*============================================================================*/
  /* Private definitions                                                        */
  /*============================================================================*/
  
  #if EP_ADD == PROJC || EP_ADD == JACOB || !defined(STRIP)
  
  /**
   * Normalizes a point represented in projective coordinates.
   *
   * @param r			- the result.
   * @param p			- the point to normalize.
   * @param inv		- the flag to indicate if z is already inverted.
   */
  static void ep_norm_imp(ep_t r, const ep_t p, int inv) {
  	if (p->coord != BASIC) {
  		fp_t t;
  
  		fp_null(t);
  
  		RLC_TRY {
  			fp_new(t);
  
  			if (inv) {
  				fp_copy(r->z, p->z);
  			} else {
  				fp_inv(r->z, p->z);
  			}
  
  			switch (p->coord) {
  				case PROJC:
  					fp_mul(r->x, p->x, r->z);
  					fp_mul(r->y, p->y, r->z);
  					break;
  				case JACOB:
  					fp_sqr(t, r->z);
  					fp_mul(r->x, p->x, t);
  					fp_mul(t, t, r->z);
  					fp_mul(r->y, p->y, t);
  					break;
  				default:
  					ep_copy(r, p);
  					break;
  			}
  			fp_set_dig(r->z, 1);
  		}
  		RLC_CATCH_ANY {
  			RLC_THROW(ERR_CAUGHT);
  		}
  		RLC_FINALLY {
  			fp_free(t);
  		}
  	}
  
  	r->coord = BASIC;
  }
  
  #endif /* EP_ADD == PROJC */
  
  /*============================================================================*/
  /* Public definitions                                                         */
  /*============================================================================*/
  
  void ep_norm(ep_t r, const ep_t p) {
  	if (ep_is_infty(p)) {
  		ep_set_infty(r);
  		return;
  	}
  
  	if (p->coord == BASIC) {
  		/* If the point is represented in affine coordinates, just copy it. */
  		ep_copy(r, p);
  		return;
  	}
  #if EP_ADD == PROJC || EP_ADD == JACOB || !defined(STRIP)
  	ep_norm_imp(r, p, 0);
  #endif /* EP_ADD == PROJC */
  }
  
  void ep_norm_sim(ep_t *r, const ep_t *t, int n) {
  	int i;
  	fp_t* a = RLC_ALLOCA(fp_t, n);
  
  	RLC_TRY {
  		if (a == NULL) {
  			RLC_THROW(ERR_NO_MEMORY);
  		}
  		for (i = 0; i < n; i++) {
  			fp_null(a[i]);
  			fp_new(a[i]);
  			fp_copy(a[i], t[i]->z);
  		}
  
  		fp_inv_sim(a, (const fp_t *)a, n);
  
  		for (i = 0; i < n; i++) {
  			fp_copy(r[i]->x, t[i]->x);
  			fp_copy(r[i]->y, t[i]->y);
  			if (!ep_is_infty(t[i])) {
  				fp_copy(r[i]->z, a[i]);
  			}
  		}
  
  		for (i = 0; i < n; i++) {
  			ep_norm_imp(r[i], r[i], 1);
  		}
  	}
  	RLC_CATCH_ANY {
  		RLC_THROW(ERR_CAUGHT);
  	}
  	RLC_FINALLY {
  		for (i = 0; i < n; i++) {
  			fp_free(a[i]);
  		}
  		RLC_FREE(a);
  	}
  }
  