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#include "mult.h"
#include "point.h"
point_t *scalar_mult_ltr(point_t *point, point_t *neg, curve_t *curve, wnaf_t *naf, size_t bits) {
point_t *q;
long i;
{% if scalarmult.complete %}
bn_naf_pad_left(naf, 0, (bits + 1) - naf->length);
q = point_copy(curve->neutral);
i = 0;
{% else %}
bn_naf_strip_left(naf, 0);
int8_t val = naf->data[0];
if (val == 1) {
q = point_copy(point);
} else if (val == -1) {
q = point_copy(neg);
}
i = 1;
{% endif %}
{% if scalarmult.always %}
point_t *q_copy = point_new();
{% endif %}
for (; i < naf->length; i++) {
point_dbl(q, curve, q);
{% if scalarmult.always %}
point_set(q, q_copy);
{% endif %}
if (naf->data[i] == 1) {
point_accumulate(q, point, curve, q);
{% if scalarmult.always %}
point_accumulate(q_copy, neg, curve, q_copy);
{% endif %}
} else if (naf->data[i] == -1) {
point_accumulate(q, neg, curve, q);
{% if scalarmult.always %}
point_accumulate(q_copy, point, curve, q_copy);
{% endif %}
}
}
{% if scalarmult.always %}
point_free(q_copy);
{% endif %}
return q;
}
point_t* scalar_mult_rtl(point_t *point, point_t *neg, curve_t *curve, wnaf_t *naf, size_t bits) {
{% if scalarmult.always %}
point_t *r_copy = point_new();
{% endif %}
{% if scalarmult.complete %}
bn_naf_pad_left(naf, 0, (bits + 1) - naf->length);
{% endif %}
bn_naf_reverse(naf);
point_t *q = point_copy(point);
point_t *r = point_copy(curve->neutral);
point_t *q_neg = point_new();
for (long i = 0; i < naf->length; i++) {
{% if scalarmult.always %}
point_set(r, r_copy);
{% endif %}
if (naf->data[i] == 1) {
point_accumulate(r, q, curve, r);
{% if scalarmult.always %}
point_neg(q, curve, q_neg);
point_accumulate(r_copy, q_neg, curve, r_copy);
{% endif %}
} else if (naf->data[i] == -1) {
point_neg(q, curve, q_neg);
point_accumulate(r, q_neg, curve, r);
{% if scalarmult.always %}
point_accumulate(r_copy, q, curve, r_copy);
{% endif %}
}
point_dbl(q, curve, q);
}
point_free(q_neg);
point_free(q);
{% if scalarmult.always %}
point_free(r_copy);
{% endif %}
return r;
}
static void scalar_mult_inner(bn_t *scalar, point_t *point, curve_t *curve, point_t *out) {
point_t *neg = point_new();
point_neg(point, curve, neg);
wnaf_t *naf = bn_bnaf(scalar);
size_t bits = bn_bit_length(&curve->n);
{% if scalarmult.direction == ProcessingDirection.LTR %}
point_t *q = scalar_mult_ltr(point, neg, curve, naf, bits);
{% elif scalarmult.direction == ProcessingDirection.RTL %}
point_t *q = scalar_mult_rtl(point, neg, curve, naf, bits);
{% endif %}
bn_naf_clear(naf);
{%- if "scl" in scalarmult.formulas %}
point_scl(q, curve, q);
{%- endif %}
point_set(q, out);
point_free(neg);
point_free(q);
}
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