15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef CRYPTO_P224_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define CRYPTO_P224_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <string> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 11c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)#include "base/strings/string_piece.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "crypto/crypto_export.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace crypto { 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// P224 implements an elliptic curve group, commonly known as P224 and defined 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// in FIPS 186-3, section D.2.2. 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace p224 { 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// An element of the field (ℤ/pℤ) is represented with 8, 28-bit limbs in 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// little endian order. 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)typedef uint32 FieldElement[8]; 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)struct CRYPTO_EXPORT Point { 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // SetFromString the value of the point from the 56 byte, external 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // representation. The external point representation is an (x, y) pair of a 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // point on the curve. Each field element is represented as a big-endian 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // number < p. 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool SetFromString(const base::StringPiece& in); 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ToString returns an external representation of the Point. 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::string ToString() const; 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // An Point is represented in Jacobian form (x/z², y/z³). 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FieldElement x, y, z; 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// kScalarBytes is the number of bytes needed to represent an element of the 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// P224 field. 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const size_t kScalarBytes = 28; 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ScalarMult computes *out = in*scalar where scalar is a 28-byte, big-endian 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// number. 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void CRYPTO_EXPORT ScalarMult(const Point& in, const uint8* scalar, Point* out); 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ScalarBaseMult computes *out = g*scalar where g is the base point of the 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// curve and scalar is a 28-byte, big-endian number. 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void CRYPTO_EXPORT ScalarBaseMult(const uint8* scalar, Point* out); 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Add computes *out = a+b. 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void CRYPTO_EXPORT Add(const Point& a, const Point& b, Point* out); 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Negate calculates out = -a; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void CRYPTO_EXPORT Negate(const Point& a, Point* out); 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace p224 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace crypto 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // CRYPTO_P224_H_ 61