12a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Copyright (c) 2013 The Chromium Authors. All rights reserved. 22a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 32a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// found in the LICENSE file. 42a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 52a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "crypto/curve25519.h" 62a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 72a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Curve25519 is specified in terms of byte strings, not numbers, so all 82a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// implementations take and return the same sequence of bits. So the byte 92a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// order is implicitly specified as in, say, SHA1. 102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// 112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Prototype for |curve25519_donna| function in 122a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// third_party/curve25519-donna/curve25519-donna.c 132a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)extern "C" int curve25519_donna(uint8*, const uint8*, const uint8*); 142a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace crypto { 162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 172a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace curve25519 { 182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void ScalarMult(const uint8* private_key, 202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) const uint8* peer_public_key, 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) uint8* shared_key) { 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) curve25519_donna(shared_key, private_key, peer_public_key); 232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// kBasePoint is the base point (generator) of the elliptic curve group. 262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// It is little-endian version of '9' followed by 31 zeros. 272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// See "Computing public keys" section of http://cr.yp.to/ecdh.html. 282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)static const unsigned char kBasePoint[32] = {9}; 292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void ScalarBaseMult(const uint8* private_key, uint8* public_key) { 312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) curve25519_donna(public_key, private_key, kBasePoint); 322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} // namespace curve25519 352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} // namespace crypto 37