2  *  Copyright (C) 2017 - This file is part of libecc project
7  *      Jean-Pierre FLORI <jean-pierre.flori@ssi.gouv.fr>
22  * success, -1 otherwise.
28 	MUST_HAVE(((in != NULL) && (in->magic == AFF_PT_MAGIC)), ret, err);  in aff_pt_check_initialized()
29 	ret = ec_shortw_crv_check_initialized(in->crv);  in aff_pt_check_initialized()
37  * function on given curve. Return 0 on success, -1 on error.
47 	ret = fp_init(&(in->x), curve->a.ctx); EG(ret, err);  in aff_pt_init()
48 	ret = fp_init(&(in->y), curve->a.ctx); EG(ret, err);  in aff_pt_init()
50 	in->crv = curve;  in aff_pt_init()
51 	in->magic = AFF_PT_MAGIC;  in aff_pt_init()
59  * 'xcoord' and 'ycoord'. Return 0 on success, -1 on error.
68 	ret = fp_copy(&(in->x), xcoord); EG(ret, err);  in aff_pt_init_from_coords()
69 	ret = fp_copy(&(in->y), ycoord);  in aff_pt_init_from_coords()
83 	if((in != NULL) && (in->magic == AFF_PT_MAGIC) && (in->crv != NULL)){  in aff_pt_uninit()
84 		in->crv = NULL;  in aff_pt_uninit()
85 		in->magic = WORD(0);  in aff_pt_uninit()
87 		fp_uninit(&(in->x));  in aff_pt_uninit()
88 		fp_uninit(&(in->y));  in aff_pt_uninit()
99  * The function returns -1 on error, 0 on success.
120 	ret = fp_mul(y2, y2, &(curve->a)); EG(ret, err);  in aff_pt_y_from_x()
122 	ret = fp_add(y1, y1,  &(curve->b)); EG(ret, err);  in aff_pt_y_from_x()
137  * the function returns -1 and 'on_curve' is left unmodified.
150 	MUST_HAVE((x->ctx == y->ctx), ret, err);  in is_on_shortw_curve()
151 	MUST_HAVE((x->ctx == curve->a.ctx), ret, err);  in is_on_shortw_curve()
154 	 * (y^2 - b) = (x^2 + a) * x  in is_on_shortw_curve()
157 	/* Compute y^2 - b */  in is_on_shortw_curve()
158 	ret = fp_init(&tmp1, x->ctx); EG(ret, err);  in is_on_shortw_curve()
160 	ret = fp_sub(&tmp1, &tmp1, &(curve->b)); EG(ret, err);  in is_on_shortw_curve()
163 	ret = fp_init(&tmp2, x->ctx); EG(ret, err);  in is_on_shortw_curve()
165 	ret = fp_add(&tmp2, &tmp2, &(curve->a)); EG(ret, err);  in is_on_shortw_curve()
190 	ret = is_on_shortw_curve(&(pt->x), &(pt->y), pt->crv, on_curve);  in aff_pt_is_on_curve()
198  * 0 is returned on success, -1 on error.
205 	ret = aff_pt_init(out, in->crv); EG(ret, err);  in ec_shortw_aff_copy()
206 	ret = fp_copy(&(out->x), &(in->x)); EG(ret, err);  in ec_shortw_aff_copy()
207 	ret = fp_copy(&(out->y), &(in->y));  in ec_shortw_aff_copy()
214  * Compare affine points 'in1' and 'in2'. On success, 0 is returned and
215  * comparison value is given using 'cmp' (0 if equal, a non-zero value
216  * if they are different). -1 is returned on error.
218 int ec_shortw_aff_cmp(aff_pt_src_t in1, aff_pt_src_t in2, int *cmp)  in ec_shortw_aff_cmp()  argument
225 	ret = aff_pt_check_initialized(in2); EG(ret, err);  in ec_shortw_aff_cmp()
227 	MUST_HAVE((in1->crv == in2->crv), ret, err);  in ec_shortw_aff_cmp()
229 	ret = fp_cmp(&(in1->x), &(in2->x), &cmp_x); EG(ret, err);  in ec_shortw_aff_cmp()
230 	ret = fp_cmp(&(in1->y), &(in2->y), &cmp_y); EG(ret, err);  in ec_shortw_aff_cmp()
239  * Check if given affine points 'in1' and 'in2' on the same curve are equal
241  *  - 1 if points are equal or opposite
242  *  - 0 if not
243  * The function returns -1 on error, in which case 'aff_is_eq_or_opp'
246 int ec_shortw_aff_eq_or_opp(aff_pt_src_t in1, aff_pt_src_t in2,  in ec_shortw_aff_eq_or_opp()  argument
252 	ret = aff_pt_check_initialized(in2); EG(ret, err);  in ec_shortw_aff_eq_or_opp()
253 	MUST_HAVE((in1->crv == in2->crv), ret, err);  in ec_shortw_aff_eq_or_opp()
256 	ret = fp_cmp(&(in1->x), &(in2->x), &cmp); EG(ret, err);  in ec_shortw_aff_eq_or_opp()
257 	ret = fp_eq_or_opp(&(in1->y), &(in2->y), &eq_or_opp); EG(ret, err);  in ec_shortw_aff_eq_or_opp()
270  * 2 * p_len. The function returns 0 on success, -1 on error.
284 	ctx = crv->a.ctx;  in aff_pt_import_from_buf()
285 	coord_len = (u16)BYTECEIL(ctx->p_bitlen);  in aff_pt_import_from_buf()
289 	ret = fp_init_from_buf(&(pt->x), ctx, pt_buf, coord_len); EG(ret, err);  in aff_pt_import_from_buf()
290 	ret = fp_init_from_buf(&(pt->y), ctx, pt_buf + coord_len, coord_len); EG(ret, err);  in aff_pt_import_from_buf()
293 	pt->crv = crv;  in aff_pt_import_from_buf()
296 	pt->magic = AFF_PT_MAGIC;  in aff_pt_import_from_buf()
306 		ret = -1;  in aff_pt_import_from_buf()
337 	coord_len = (u16)BYTECEIL(pt->crv->a.ctx->p_bitlen);  in aff_pt_export_to_buf()
341 	ret = fp_export_to_buf(pt_buf, coord_len, &(pt->x)); EG(ret, err);  in aff_pt_export_to_buf()
342 	ret = fp_export_to_buf(pt_buf + coord_len, coord_len, &(pt->y));  in aff_pt_export_to_buf()