1 files changed, 82 insertions, 0 deletions
diff --git a/src/math/field.c b/src/math/field.c
new file mode 100644
index 0000000..ba2972c
--- /dev/null
+++ b/src/math/field.c
@@ -0,0 +1,82 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+#include "field.h"
+#include "poly.h"
+#include "random.h"
+
+GEN field_primer(long bits) { return random_prime(bits); }
+
+GEN field_binaryr(long bits) {
+	if (poly_exists(bits)) {
+		return poly_find_gen(bits);
+	} else {
+		fprintf(stderr,
+		        "Unable to find a suitable binary field. Use an explicit one.");
+		exit(1);
+	}
+}
+
+int field_random(curve_t *curve, config_t *config, ...) {
+	switch (config->field) {
+		case FIELD_PRIME:
+			curve->field = field_primer(config->bits);
+			return 1;
+		case FIELD_BINARY:
+			curve->field = field_binaryr(config->bits);
+			return 1;
+		default:
+			return 0; /* NOT REACHABLE */
+	}
+}
+
+int field_input(curve_t *curve, config_t *config, ...) {
+	return -1;  // NOT IMPLEMENTED
+}
+
+GEN field_params(GEN field) {
+	pari_sp ltop = avma;
+
+	if (typ(field) == t_INT) {
+		GEN p3 = cgetg(2, t_VEC);
+		gel(p3, 1) = gcopy(field);
+		return gerepilecopy(ltop, p3);
+	}
+
+	GEN out = gtovec0(gen_0, 3);
+
+	long j = 1;
+	long l2 = glength(member_mod(field)) - 2;
+	{
+		pari_sp btop = avma;
+		for (long i = 0; i <= l2; ++i) {
+			GEN c = polcoeff0(member_mod(field), i, -1);
+			if (cmpis(c, 0) != 0) {
+				gel(out, j) = stoi(i);
+				j++;
+			}
+			if (gc_needed(btop, 1)) gerepileall(btop, 3, &out, &c);
+		}
+	}
+	return gerepilecopy(ltop, out);
+}
+
+GEN field_elementi(GEN element) {
+	switch (typ(element)) {
+		case t_INT:
+			return element;
+		case t_INTMOD:
+			return lift(element);
+		case t_FFELT: {
+			pari_sp ltop = avma;
+			GEN coeffs = FF_to_FpXQ(element);
+			GEN vec = gtovec(coeffs);
+			GEN n = fromdigits(vec, stoi(2));
+			return gerepilecopy(ltop, n);
+		}
+		default:
+			pari_err_TYPE("field_elementi", element);
+			return NULL; /* NOT REACHABLE */
+	}
+}
+\ No newline at end of file