5 #include <mLib/alloc.h>
8 #include <mLib/macros.h>
13 #include "field-guts.h"
15 static void puthex(const char *name, mp *x, size_t n)
21 if (!n) n = mp_octets(x);
27 hex_encode(&hc, p, n, &d);
28 hex_encode(&hc, 0, 0, &d);
29 printf(" %s 0x", name);
30 dstr_write(&d, stdout);
36 int main(int argc, char *argv[])
46 mp *x, *y = 0, *yy = 0;
52 if ((c = ec_curveparse(&qd)) == 0 || !qd_eofp(&qd)) {
53 fprintf(stderr, "bad curve: %s\n", qd.e);
59 ei.r = mp_readstring(MP_NEW, argv[2], 0, 0);
60 ei.h = mp_readstring(MP_NEW, argv[3], 0, 0);
64 hex_decode(&hc, argv[4], strlen(argv[4]), &d);
65 hex_decode(&hc, 0, 0, &d);
71 fprintf(stderr, "missing x\n");
74 x = mp_loadb(MP_NEW, p + 1, n);
76 if (d.len < 2 * n + 1) {
77 fprintf(stderr, "missing y\n");
80 y = mp_loadb(MP_NEW, p + n + 1, n);
83 if (!ec_find(c, &pt, x)) {
84 fprintf(stderr, "no matching y\n");
89 switch (F_TYPE(c->f)) {
91 if (!MP_ODDP(yy) != !(p[0] & 1))
92 yy = mp_sub(yy, c->f->m, yy);
96 yy = F_SQRT(c->f, MP_NEW, c->b);
98 mp *xin = F_IN(c->f, MP_NEW, x);
99 mp *xx = F_SQR(c->f, MP_NEW, xin);
100 mp *b = F_MUL(c->f, MP_NEW, xx, c->a);
101 mp *xxx = F_MUL(c->f, MP_NEW, xx, xin);
102 b = F_ADD(c->f, b, b, xxx);
103 b = F_ADD(c->f, b, b, c->b);
104 xx = F_INV(c->f, xx, xx);
105 b = F_MUL(c->f, b, b, xx);
107 yy = F_QUADSOLVE(c->f, MP_NEW, b);
108 xx = F_OUT(c->f, xx, yy);
109 if (!MP_ODDP(xx) != !(p[0] & 1))
110 yy = gf_add(yy, yy, MP_ONE);
111 yy = F_MUL(c->f, yy, yy, xin);
112 yy = F_OUT(c->f, yy, yy);
121 if (y && yy && !MP_EQ(y, yy)) {
122 fprintf(stderr, "inconsistent answers\n");
126 ei.g.y = mp_copy(y ? y : yy);
127 mp_drop(y); mp_drop(yy);
130 if ((err = ec_checkinfo(&ei, &rand_global)) != 0)
131 fprintf(stderr, "bad curve: %s\n", err);
132 puthex("p", ei.c->f->m, 0);
133 if (STRCMP(F_NAME(ei.c->f), ==, "binnorm")) {
134 fctx_binnorm *fc = (fctx_binnorm *)ei.c->f;
135 puthex("beta", fc->ntop.r[fc->ntop.n - 1], c->f->noctets);
137 t = F_OUT(ei.c->f, t, ei.c->a); puthex("a", t, c->f->noctets);
138 t = F_OUT(ei.c->f, t, ei.c->b); puthex("b", t, c->f->noctets);
139 puthex("r", ei.r, c->f->noctets);
140 printf(" h "); mp_writefile(ei.h, stdout, 10); putchar('\n');
141 puthex("gx", ei.g.x, c->f->noctets);
142 puthex("gy", ei.g.y, c->f->noctets);