5 files changed, 179 insertions, 0 deletions
diff --git a/src/gp/equation.gp b/src/gp/equation.gp
new file mode 100644
index 0000000..c1483e4
--- /dev/null
+++ b/src/gp/equation.gp
@@ -0,0 +1,28 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+
+/**
+ * Constructs an elliptic curve in the form E:
+ *		y^2 = x^3 + ax + b, over a prime field
+ * @param a
+ * @param b
+ * @param p
+ * @returns elliptic curve
+ */
+prime_weierstrass(a:int, b:int, field:gen) = {
+	return(ellinit([a,b], field));
+}
+
+/**
+ * Constructs an elliptic curve in the form E:
+ *		y^2 + xy = x^3 + ax + b, over a binary field.
+ * @param a
+ * @param b
+ * @param field
+ * @returns elliptic curve
+ */
+binary_weierstrass(a:int, b:int, field:gen) = {
+	return(ellinit([1,0,0,a,b], field));
+}
diff --git a/src/gp/field.gp b/src/gp/field.gp
new file mode 100644
index 0000000..c428abd
--- /dev/null
+++ b/src/gp/field.gp
@@ -0,0 +1,33 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+
+/**
+ * Extract a field representation from a field.
+ *  - char(field) == 2:
+ *    returns the vector of powers of middle coefficients of the reduction polynomial.
+ *  - char(field) != 2:
+ *     returns the field characteristic(p).
+ *
+ * @return field representation
+ */
+field_params(field:gen) = {
+	if(type(field) == "t_INT",
+		return([field]);
+	);
+
+	local(out:vec, j:int, c:int);
+	out = vector(3);
+
+	j = 1;
+	for(i=2, length(field.mod) - 2,
+		c = polcoeff(field.mod, i):int;
+		if(c != 0,
+			out[j] = i;
+			j++;
+		);
+	);
+
+	return(out);
+}
+\ No newline at end of file
diff --git a/src/gp/gp.gp b/src/gp/gp.gp
new file mode 100644
index 0000000..0124958
--- /dev/null
+++ b/src/gp/gp.gp
@@ -0,0 +1,7 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017  J08nY
+ */
+
+\r gp/utils
+\r gp/invalid
+\ No newline at end of file
diff --git a/src/gp/invalid.gp b/src/gp/invalid.gp
new file mode 100644
index 0000000..4970014
--- /dev/null
+++ b/src/gp/invalid.gp
@@ -0,0 +1,59 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+
+/**
+ * Computes primes upto some upper bound.
+ *
+ * @param bound an upper bound on primes
+ * @return a vector of primes up to bound^2
+ */
+prime_upto(bound:int) = {
+	local(p:list, product:int, last:int, result:vec);
+	p = List();
+
+	bound = bound^2;
+	listput(p, 2);
+	product = 2;
+	last = 2;
+
+	while(product < bound,
+		last = nextprime(last + 1);
+		listput(p, last);
+		product = product * last;
+	);
+
+	result = list_to_vec(p);
+	listkill(p);
+	return(result);
+}
+
+/**
+ *
+ */
+invalid(coeffs:vec, field:pol, primes:vec, bits:int) = {
+	local(bs:vec, cs:vec, eq:vec, e:ell, b, n, c, o):int;
+	n = length(primes);
+	bs = vector(n);
+	eq = coeffs;
+	c = 0;
+
+	while(c < n,
+		b = random_int(bits):int;
+		eq[4] = b; /* Times field? */
+
+		iferr(e = ellinit(eq,field):ell, E, next());
+
+		o = ellsea(e):int;
+		for(i=1,n,
+			if((o % primes[i]) == 0 && bs[i] == 0,
+				bs[i] = b;
+				cs[i] = e;
+				c = c + 1;
+			);
+		);
+	);
+
+	return(cs);
+}
+\ No newline at end of file
diff --git a/src/gp/utils.gp b/src/gp/utils.gp
new file mode 100644
index 0000000..932a44a
--- /dev/null
+++ b/src/gp/utils.gp
@@ -0,0 +1,52 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+
+ random_primer(range:vec) = {
+ 	local(p:int);
+ 	until(isprime(p),
+ 		p = randomprime(range):int;
+ 	);
+ 	return(p);
+ }
+
+/**
+ * Calculates a random prime of bit size bits.
+ *
+ * @param bits bit size of the requested prime
+ * @return random prime between 2^(bits - 1) and 2^bits
+ */
+random_prime(bits:small) = {
+	return(random_primer([2^(bits-1), 2^bits]));
+}
+
+random_intr(range:vec) = {
+	return(random(range));
+}
+
+/**
+ * Generates a random integer with bit size bits.
+ *
+ * @param bits bit size of the requested integer
+ * @return random int between 2^(bits - 1) and 2^bits
+ */
+random_int(bits:small) = {
+	return(random_intr([2^(bits-1), 2^bits]));
+}
+
+/**
+ * Converts a list to a vector.
+ *
+ * @param l list to convert
+ * @return a vector of the lists values
+ */
+list_to_vec(l:list) = {
+	local(v:vec, n:int);
+	n = length(l);
+	v = vector(n);
+	for(i=1, n,
+		v[i] = l[i];
+	);
+	return(v);
+}
+\ No newline at end of file