--- /dev/null
+"use strict";
+/**
+ * @fileOverview
+ * Core operations on curve 25519 required for the higher level modules.
+ */
+
+/*
+ * Copyright (c) 2007, 2013, 2014 Michele Bini
+ * Copyright (c) 2014 Mega Limited
+ * under the MIT License.
+ *
+ * Authors: Guy K. Kloss, Michele Bini
+ *
+ * You should have received a copy of the license along with this program.
+ */
+
+var core = require('./core');
+var utils = require('./utils');
+
+ /**
+ * @exports jodid25519/curve255
+ * Legacy compatibility module for Michele Bini's previous curve255.js.
+ *
+ * @description
+ * Legacy compatibility module for Michele Bini's previous curve255.js.
+ *
+ * <p>
+ * This code presents an API with all key formats as previously available
+ * from Michele Bini's curve255.js implementation.
+ * </p>
+ */
+ var ns = {};
+
+ function curve25519_raw(f, c) {
+ var a, x_1, q;
+
+ x_1 = c;
+ a = core.dbl(x_1, core.ONE());
+ q = [x_1, core.ONE()];
+
+ var n = 255;
+
+ while (core.getbit(f, n) == 0) {
+ n--;
+ // For correct constant-time operation, bit 255 should always be
+ // set to 1 so the following 'while' loop is never entered.
+ if (n < 0) {
+ return core.ZERO();
+ }
+ }
+ n--;
+
+ var aq = [a, q];
+
+ while (n >= 0) {
+ var r, s;
+ var b = core.getbit(f, n);
+ r = core.sum(aq[0][0], aq[0][1], aq[1][0], aq[1][1], x_1);
+ s = core.dbl(aq[1 - b][0], aq[1 - b][1]);
+ aq[1 - b] = s;
+ aq[b] = r;
+ n--;
+ }
+ q = aq[1];
+
+ q[1] = core.invmodp(q[1]);
+ q[0] = core.mulmodp(q[0], q[1]);
+ core.reduce(q[0]);
+ return q[0];
+ }
+
+ function curve25519b32(a, b) {
+ return _base32encode(curve25519(_base32decode(a),
+ _base32decode(b)));
+ }
+
+ function curve25519(f, c) {
+ if (!c) {
+ c = core.BASE();
+ }
+ f[0] &= 0xFFF8;
+ f[15] = (f[15] & 0x7FFF) | 0x4000;
+ return curve25519_raw(f, c);
+ }
+
+ function _hexEncodeVector(k) {
+ var hexKey = utils.hexEncode(k);
+ // Pad with '0' at the front.
+ hexKey = new Array(64 + 1 - hexKey.length).join('0') + hexKey;
+ // Invert bytes.
+ return hexKey.split(/(..)/).reverse().join('');
+ }
+
+ function _hexDecodeVector(v) {
+ // assert(length(x) == 64);
+ // Invert bytes.
+ var hexKey = v.split(/(..)/).reverse().join('');
+ return utils.hexDecode(hexKey);
+ }
+
+
+ // Expose some functions to the outside through this name space.
+
+ /**
+ * Computes the scalar product of a point on the curve 25519.
+ *
+ * This function is used for the DH key-exchange protocol.
+ *
+ * Before multiplication, some bit operations are applied to the
+ * private key to ensure it is a valid Curve25519 secret key.
+ * It is the user's responsibility to make sure that the private
+ * key is a uniformly random, secret value.
+ *
+ * @function
+ * @param f {array}
+ * Private key.
+ * @param c {array}
+ * Public point on the curve. If not given, the curve's base point is used.
+ * @returns {array}
+ * Key point resulting from scalar product.
+ */
+ ns.curve25519 = curve25519;
+
+ /**
+ * Computes the scalar product of a point on the curve 25519.
+ *
+ * This variant does not make sure that the private key is valid.
+ * The user has the responsibility to ensure the private key is
+ * valid or that this results in a safe protocol. Unless you know
+ * exactly what you are doing, you should not use this variant,
+ * please use 'curve25519' instead.
+ *
+ * @function
+ * @param f {array}
+ * Private key.
+ * @param c {array}
+ * Public point on the curve. If not given, the curve's base point is used.
+ * @returns {array}
+ * Key point resulting from scalar product.
+ */
+ ns.curve25519_raw = curve25519_raw;
+
+ /**
+ * Encodes the internal representation of a key to a canonical hex
+ * representation.
+ *
+ * This is the format commonly used in other libraries and for
+ * test vectors, and is equivalent to the hex dump of the key in
+ * little-endian binary format.
+ *
+ * @function
+ * @param n {array}
+ * Array representation of key.
+ * @returns {string}
+ * Hexadecimal string representation of key.
+ */
+ ns.hexEncodeVector = _hexEncodeVector;
+
+ /**
+ * Decodes a canonical hex representation of a key
+ * to an internally compatible array representation.
+ *
+ * @function
+ * @param n {string}
+ * Hexadecimal string representation of key.
+ * @returns {array}
+ * Array representation of key.
+ */
+ ns.hexDecodeVector = _hexDecodeVector;
+
+ /**
+ * Encodes the internal representation of a key into a
+ * hexadecimal representation.
+ *
+ * This is a strict positional notation, most significant digit first.
+ *
+ * @function
+ * @param n {array}
+ * Array representation of key.
+ * @returns {string}
+ * Hexadecimal string representation of key.
+ */
+ ns.hexencode = utils.hexEncode;
+
+ /**
+ * Decodes a hex representation of a key to an internally
+ * compatible array representation.
+ *
+ * @function
+ * @param n {string}
+ * Hexadecimal string representation of key.
+ * @returns {array}
+ * Array representation of key.
+ */
+ ns.hexdecode = utils.hexDecode;
+
+ /**
+ * Encodes the internal representation of a key to a base32
+ * representation.
+ *
+ * @function
+ * @param n {array}
+ * Array representation of key.
+ * @returns {string}
+ * Base32 string representation of key.
+ */
+ ns.base32encode = utils.base32encode;
+
+ /**
+ * Decodes a base32 representation of a key to an internally
+ * compatible array representation.
+ *
+ * @function
+ * @param n {string}
+ * Base32 string representation of key.
+ * @returns {array}
+ * Array representation of key.
+ */
+ ns.base32decode = utils.base32decode;
+
+module.exports = ns;
Code Review / simantics / district.git / blobdiff