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features/mbedtls/src/ecp.c@3:1198227e6421, 2016-12-16 (annotated)

Committer:: switches
Date:: Fri Dec 16 16:27:57 2016 +0000
Revision:: 3:1198227e6421
Parent:: 0:5c4d7b2438d3

Changed ADC scale for MAX32625 platforms to 1.2V full scale to match MAX32630 platforms

Who changed what in which revision?

User	Revision	Line number	New contents of line
switches	0:5c4d7b2438d3	1	/*
switches	0:5c4d7b2438d3	2	* Elliptic curves over GF(p): generic functions
switches	0:5c4d7b2438d3	3	*
switches	0:5c4d7b2438d3	4	* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
switches	0:5c4d7b2438d3	5	* SPDX-License-Identifier: Apache-2.0
switches	0:5c4d7b2438d3	6	*
switches	0:5c4d7b2438d3	7	* Licensed under the Apache License, Version 2.0 (the "License"); you may
switches	0:5c4d7b2438d3	8	* not use this file except in compliance with the License.
switches	0:5c4d7b2438d3	9	* You may obtain a copy of the License at
switches	0:5c4d7b2438d3	10	*
switches	0:5c4d7b2438d3	11	* http://www.apache.org/licenses/LICENSE-2.0
switches	0:5c4d7b2438d3	12	*
switches	0:5c4d7b2438d3	13	* Unless required by applicable law or agreed to in writing, software
switches	0:5c4d7b2438d3	14	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
switches	0:5c4d7b2438d3	15	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
switches	0:5c4d7b2438d3	16	* See the License for the specific language governing permissions and
switches	0:5c4d7b2438d3	17	* limitations under the License.
switches	0:5c4d7b2438d3	18	*
switches	0:5c4d7b2438d3	19	* This file is part of mbed TLS (https://tls.mbed.org)
switches	0:5c4d7b2438d3	20	*/
switches	0:5c4d7b2438d3	21
switches	0:5c4d7b2438d3	22	/*
switches	0:5c4d7b2438d3	23	* References:
switches	0:5c4d7b2438d3	24	*
switches	0:5c4d7b2438d3	25	* SEC1 http://www.secg.org/index.php?action=secg,docs_secg
switches	0:5c4d7b2438d3	26	* GECC = Guide to Elliptic Curve Cryptography - Hankerson, Menezes, Vanstone
switches	0:5c4d7b2438d3	27	* FIPS 186-3 http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf
switches	0:5c4d7b2438d3	28	* RFC 4492 for the related TLS structures and constants
switches	0:5c4d7b2438d3	29	*
switches	0:5c4d7b2438d3	30	* [Curve25519] http://cr.yp.to/ecdh/curve25519-20060209.pdf
switches	0:5c4d7b2438d3	31	*
switches	0:5c4d7b2438d3	32	* [2] CORON, Jean-S'ebastien. Resistance against differential power analysis
switches	0:5c4d7b2438d3	33	* for elliptic curve cryptosystems. In : Cryptographic Hardware and
switches	0:5c4d7b2438d3	34	* Embedded Systems. Springer Berlin Heidelberg, 1999. p. 292-302.
switches	0:5c4d7b2438d3	35	* <http://link.springer.com/chapter/10.1007/3-540-48059-5_25>
switches	0:5c4d7b2438d3	36	*
switches	0:5c4d7b2438d3	37	* [3] HEDABOU, Mustapha, PINEL, Pierre, et B'EN'ETEAU, Lucien. A comb method to
switches	0:5c4d7b2438d3	38	* render ECC resistant against Side Channel Attacks. IACR Cryptology
switches	0:5c4d7b2438d3	39	* ePrint Archive, 2004, vol. 2004, p. 342.
switches	0:5c4d7b2438d3	40	* <http://eprint.iacr.org/2004/342.pdf>
switches	0:5c4d7b2438d3	41	*/
switches	0:5c4d7b2438d3	42
switches	0:5c4d7b2438d3	43	#if !defined(MBEDTLS_CONFIG_FILE)
switches	0:5c4d7b2438d3	44	#include "mbedtls/config.h"
switches	0:5c4d7b2438d3	45	#else
switches	0:5c4d7b2438d3	46	#include MBEDTLS_CONFIG_FILE
switches	0:5c4d7b2438d3	47	#endif
switches	0:5c4d7b2438d3	48
switches	0:5c4d7b2438d3	49	#if defined(MBEDTLS_ECP_C)
switches	0:5c4d7b2438d3	50
switches	0:5c4d7b2438d3	51	#include "mbedtls/ecp.h"
switches	0:5c4d7b2438d3	52
switches	0:5c4d7b2438d3	53	#include <string.h>
switches	0:5c4d7b2438d3	54
switches	0:5c4d7b2438d3	55	#if defined(MBEDTLS_PLATFORM_C)
switches	0:5c4d7b2438d3	56	#include "mbedtls/platform.h"
switches	0:5c4d7b2438d3	57	#else
switches	0:5c4d7b2438d3	58	#include <stdlib.h>
switches	0:5c4d7b2438d3	59	#include <stdio.h>
switches	0:5c4d7b2438d3	60	#define mbedtls_printf printf
switches	0:5c4d7b2438d3	61	#define mbedtls_calloc calloc
switches	0:5c4d7b2438d3	62	#define mbedtls_free free
switches	0:5c4d7b2438d3	63	#endif
switches	0:5c4d7b2438d3	64
switches	0:5c4d7b2438d3	65	#if ( defined(__ARMCC_VERSION) \|\| defined(_MSC_VER) ) && \
switches	0:5c4d7b2438d3	66	!defined(inline) && !defined(__cplusplus)
switches	0:5c4d7b2438d3	67	#define inline __inline
switches	0:5c4d7b2438d3	68	#endif
switches	0:5c4d7b2438d3	69
switches	0:5c4d7b2438d3	70	/* Implementation that should never be optimized out by the compiler */
switches	0:5c4d7b2438d3	71	static void mbedtls_zeroize( void *v, size_t n ) {
switches	0:5c4d7b2438d3	72	volatile unsigned char p = v; while( n-- ) p++ = 0;
switches	0:5c4d7b2438d3	73	}
switches	0:5c4d7b2438d3	74
switches	0:5c4d7b2438d3	75	#if defined(MBEDTLS_SELF_TEST)
switches	0:5c4d7b2438d3	76	/*
switches	0:5c4d7b2438d3	77	* Counts of point addition and doubling, and field multiplications.
switches	0:5c4d7b2438d3	78	* Used to test resistance of point multiplication to simple timing attacks.
switches	0:5c4d7b2438d3	79	*/
switches	0:5c4d7b2438d3	80	static unsigned long add_count, dbl_count, mul_count;
switches	0:5c4d7b2438d3	81	#endif
switches	0:5c4d7b2438d3	82
switches	0:5c4d7b2438d3	83	#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	84	defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	85	defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	86	defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	87	defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	88	defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	89	defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	90	defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	91	defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	92	defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) \|\| \
switches	0:5c4d7b2438d3	93	defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
switches	0:5c4d7b2438d3	94	#define ECP_SHORTWEIERSTRASS
switches	0:5c4d7b2438d3	95	#endif
switches	0:5c4d7b2438d3	96
switches	0:5c4d7b2438d3	97	#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
switches	0:5c4d7b2438d3	98	#define ECP_MONTGOMERY
switches	0:5c4d7b2438d3	99	#endif
switches	0:5c4d7b2438d3	100
switches	0:5c4d7b2438d3	101	/*
switches	0:5c4d7b2438d3	102	* Curve types: internal for now, might be exposed later
switches	0:5c4d7b2438d3	103	*/
switches	0:5c4d7b2438d3	104	typedef enum
switches	0:5c4d7b2438d3	105	{
switches	0:5c4d7b2438d3	106	ECP_TYPE_NONE = 0,
switches	0:5c4d7b2438d3	107	ECP_TYPE_SHORT_WEIERSTRASS, /* y^2 = x^3 + a x + b */
switches	0:5c4d7b2438d3	108	ECP_TYPE_MONTGOMERY, /* y^2 = x^3 + a x^2 + x */
switches	0:5c4d7b2438d3	109	} ecp_curve_type;
switches	0:5c4d7b2438d3	110
switches	0:5c4d7b2438d3	111	/*
switches	0:5c4d7b2438d3	112	* List of supported curves:
switches	0:5c4d7b2438d3	113	* - internal ID
switches	0:5c4d7b2438d3	114	* - TLS NamedCurve ID (RFC 4492 sec. 5.1.1, RFC 7071 sec. 2)
switches	0:5c4d7b2438d3	115	* - size in bits
switches	0:5c4d7b2438d3	116	* - readable name
switches	0:5c4d7b2438d3	117	*
switches	0:5c4d7b2438d3	118	* Curves are listed in order: largest curves first, and for a given size,
switches	0:5c4d7b2438d3	119	* fastest curves first. This provides the default order for the SSL module.
switches	0:5c4d7b2438d3	120	*
switches	0:5c4d7b2438d3	121	* Reminder: update profiles in x509_crt.c when adding a new curves!
switches	0:5c4d7b2438d3	122	*/
switches	0:5c4d7b2438d3	123	static const mbedtls_ecp_curve_info ecp_supported_curves[] =
switches	0:5c4d7b2438d3	124	{
switches	0:5c4d7b2438d3	125	#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
switches	0:5c4d7b2438d3	126	{ MBEDTLS_ECP_DP_SECP521R1, 25, 521, "secp521r1" },
switches	0:5c4d7b2438d3	127	#endif
switches	0:5c4d7b2438d3	128	#if defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
switches	0:5c4d7b2438d3	129	{ MBEDTLS_ECP_DP_BP512R1, 28, 512, "brainpoolP512r1" },
switches	0:5c4d7b2438d3	130	#endif
switches	0:5c4d7b2438d3	131	#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
switches	0:5c4d7b2438d3	132	{ MBEDTLS_ECP_DP_SECP384R1, 24, 384, "secp384r1" },
switches	0:5c4d7b2438d3	133	#endif
switches	0:5c4d7b2438d3	134	#if defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
switches	0:5c4d7b2438d3	135	{ MBEDTLS_ECP_DP_BP384R1, 27, 384, "brainpoolP384r1" },
switches	0:5c4d7b2438d3	136	#endif
switches	0:5c4d7b2438d3	137	#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
switches	0:5c4d7b2438d3	138	{ MBEDTLS_ECP_DP_SECP256R1, 23, 256, "secp256r1" },
switches	0:5c4d7b2438d3	139	#endif
switches	0:5c4d7b2438d3	140	#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
switches	0:5c4d7b2438d3	141	{ MBEDTLS_ECP_DP_SECP256K1, 22, 256, "secp256k1" },
switches	0:5c4d7b2438d3	142	#endif
switches	0:5c4d7b2438d3	143	#if defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
switches	0:5c4d7b2438d3	144	{ MBEDTLS_ECP_DP_BP256R1, 26, 256, "brainpoolP256r1" },
switches	0:5c4d7b2438d3	145	#endif
switches	0:5c4d7b2438d3	146	#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
switches	0:5c4d7b2438d3	147	{ MBEDTLS_ECP_DP_SECP224R1, 21, 224, "secp224r1" },
switches	0:5c4d7b2438d3	148	#endif
switches	0:5c4d7b2438d3	149	#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
switches	0:5c4d7b2438d3	150	{ MBEDTLS_ECP_DP_SECP224K1, 20, 224, "secp224k1" },
switches	0:5c4d7b2438d3	151	#endif
switches	0:5c4d7b2438d3	152	#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
switches	0:5c4d7b2438d3	153	{ MBEDTLS_ECP_DP_SECP192R1, 19, 192, "secp192r1" },
switches	0:5c4d7b2438d3	154	#endif
switches	0:5c4d7b2438d3	155	#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
switches	0:5c4d7b2438d3	156	{ MBEDTLS_ECP_DP_SECP192K1, 18, 192, "secp192k1" },
switches	0:5c4d7b2438d3	157	#endif
switches	0:5c4d7b2438d3	158	{ MBEDTLS_ECP_DP_NONE, 0, 0, NULL },
switches	0:5c4d7b2438d3	159	};
switches	0:5c4d7b2438d3	160
switches	0:5c4d7b2438d3	161	#define ECP_NB_CURVES sizeof( ecp_supported_curves ) / \
switches	0:5c4d7b2438d3	162	sizeof( ecp_supported_curves[0] )
switches	0:5c4d7b2438d3	163
switches	0:5c4d7b2438d3	164	static mbedtls_ecp_group_id ecp_supported_grp_id[ECP_NB_CURVES];
switches	0:5c4d7b2438d3	165
switches	0:5c4d7b2438d3	166	/*
switches	0:5c4d7b2438d3	167	* List of supported curves and associated info
switches	0:5c4d7b2438d3	168	*/
switches	0:5c4d7b2438d3	169	const mbedtls_ecp_curve_info *mbedtls_ecp_curve_list( void )
switches	0:5c4d7b2438d3	170	{
switches	0:5c4d7b2438d3	171	return( ecp_supported_curves );
switches	0:5c4d7b2438d3	172	}
switches	0:5c4d7b2438d3	173
switches	0:5c4d7b2438d3	174	/*
switches	0:5c4d7b2438d3	175	* List of supported curves, group ID only
switches	0:5c4d7b2438d3	176	*/
switches	0:5c4d7b2438d3	177	const mbedtls_ecp_group_id *mbedtls_ecp_grp_id_list( void )
switches	0:5c4d7b2438d3	178	{
switches	0:5c4d7b2438d3	179	static int init_done = 0;
switches	0:5c4d7b2438d3	180
switches	0:5c4d7b2438d3	181	if( ! init_done )
switches	0:5c4d7b2438d3	182	{
switches	0:5c4d7b2438d3	183	size_t i = 0;
switches	0:5c4d7b2438d3	184	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	185
switches	0:5c4d7b2438d3	186	for( curve_info = mbedtls_ecp_curve_list();
switches	0:5c4d7b2438d3	187	curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
switches	0:5c4d7b2438d3	188	curve_info++ )
switches	0:5c4d7b2438d3	189	{
switches	0:5c4d7b2438d3	190	ecp_supported_grp_id[i++] = curve_info->grp_id;
switches	0:5c4d7b2438d3	191	}
switches	0:5c4d7b2438d3	192	ecp_supported_grp_id[i] = MBEDTLS_ECP_DP_NONE;
switches	0:5c4d7b2438d3	193
switches	0:5c4d7b2438d3	194	init_done = 1;
switches	0:5c4d7b2438d3	195	}
switches	0:5c4d7b2438d3	196
switches	0:5c4d7b2438d3	197	return( ecp_supported_grp_id );
switches	0:5c4d7b2438d3	198	}
switches	0:5c4d7b2438d3	199
switches	0:5c4d7b2438d3	200	/*
switches	0:5c4d7b2438d3	201	* Get the curve info for the internal identifier
switches	0:5c4d7b2438d3	202	*/
switches	0:5c4d7b2438d3	203	const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_grp_id( mbedtls_ecp_group_id grp_id )
switches	0:5c4d7b2438d3	204	{
switches	0:5c4d7b2438d3	205	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	206
switches	0:5c4d7b2438d3	207	for( curve_info = mbedtls_ecp_curve_list();
switches	0:5c4d7b2438d3	208	curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
switches	0:5c4d7b2438d3	209	curve_info++ )
switches	0:5c4d7b2438d3	210	{
switches	0:5c4d7b2438d3	211	if( curve_info->grp_id == grp_id )
switches	0:5c4d7b2438d3	212	return( curve_info );
switches	0:5c4d7b2438d3	213	}
switches	0:5c4d7b2438d3	214
switches	0:5c4d7b2438d3	215	return( NULL );
switches	0:5c4d7b2438d3	216	}
switches	0:5c4d7b2438d3	217
switches	0:5c4d7b2438d3	218	/*
switches	0:5c4d7b2438d3	219	* Get the curve info from the TLS identifier
switches	0:5c4d7b2438d3	220	*/
switches	0:5c4d7b2438d3	221	const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_tls_id( uint16_t tls_id )
switches	0:5c4d7b2438d3	222	{
switches	0:5c4d7b2438d3	223	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	224
switches	0:5c4d7b2438d3	225	for( curve_info = mbedtls_ecp_curve_list();
switches	0:5c4d7b2438d3	226	curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
switches	0:5c4d7b2438d3	227	curve_info++ )
switches	0:5c4d7b2438d3	228	{
switches	0:5c4d7b2438d3	229	if( curve_info->tls_id == tls_id )
switches	0:5c4d7b2438d3	230	return( curve_info );
switches	0:5c4d7b2438d3	231	}
switches	0:5c4d7b2438d3	232
switches	0:5c4d7b2438d3	233	return( NULL );
switches	0:5c4d7b2438d3	234	}
switches	0:5c4d7b2438d3	235
switches	0:5c4d7b2438d3	236	/*
switches	0:5c4d7b2438d3	237	* Get the curve info from the name
switches	0:5c4d7b2438d3	238	*/
switches	0:5c4d7b2438d3	239	const mbedtls_ecp_curve_info mbedtls_ecp_curve_info_from_name( const char name )
switches	0:5c4d7b2438d3	240	{
switches	0:5c4d7b2438d3	241	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	242
switches	0:5c4d7b2438d3	243	for( curve_info = mbedtls_ecp_curve_list();
switches	0:5c4d7b2438d3	244	curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
switches	0:5c4d7b2438d3	245	curve_info++ )
switches	0:5c4d7b2438d3	246	{
switches	0:5c4d7b2438d3	247	if( strcmp( curve_info->name, name ) == 0 )
switches	0:5c4d7b2438d3	248	return( curve_info );
switches	0:5c4d7b2438d3	249	}
switches	0:5c4d7b2438d3	250
switches	0:5c4d7b2438d3	251	return( NULL );
switches	0:5c4d7b2438d3	252	}
switches	0:5c4d7b2438d3	253
switches	0:5c4d7b2438d3	254	/*
switches	0:5c4d7b2438d3	255	* Get the type of a curve
switches	0:5c4d7b2438d3	256	*/
switches	0:5c4d7b2438d3	257	static inline ecp_curve_type ecp_get_type( const mbedtls_ecp_group *grp )
switches	0:5c4d7b2438d3	258	{
switches	0:5c4d7b2438d3	259	if( grp->G.X.p == NULL )
switches	0:5c4d7b2438d3	260	return( ECP_TYPE_NONE );
switches	0:5c4d7b2438d3	261
switches	0:5c4d7b2438d3	262	if( grp->G.Y.p == NULL )
switches	0:5c4d7b2438d3	263	return( ECP_TYPE_MONTGOMERY );
switches	0:5c4d7b2438d3	264	else
switches	0:5c4d7b2438d3	265	return( ECP_TYPE_SHORT_WEIERSTRASS );
switches	0:5c4d7b2438d3	266	}
switches	0:5c4d7b2438d3	267
switches	0:5c4d7b2438d3	268	/*
switches	0:5c4d7b2438d3	269	* Initialize (the components of) a point
switches	0:5c4d7b2438d3	270	*/
switches	0:5c4d7b2438d3	271	void mbedtls_ecp_point_init( mbedtls_ecp_point *pt )
switches	0:5c4d7b2438d3	272	{
switches	0:5c4d7b2438d3	273	if( pt == NULL )
switches	0:5c4d7b2438d3	274	return;
switches	0:5c4d7b2438d3	275
switches	0:5c4d7b2438d3	276	mbedtls_mpi_init( &pt->X );
switches	0:5c4d7b2438d3	277	mbedtls_mpi_init( &pt->Y );
switches	0:5c4d7b2438d3	278	mbedtls_mpi_init( &pt->Z );
switches	0:5c4d7b2438d3	279	}
switches	0:5c4d7b2438d3	280
switches	0:5c4d7b2438d3	281	/*
switches	0:5c4d7b2438d3	282	* Initialize (the components of) a group
switches	0:5c4d7b2438d3	283	*/
switches	0:5c4d7b2438d3	284	void mbedtls_ecp_group_init( mbedtls_ecp_group *grp )
switches	0:5c4d7b2438d3	285	{
switches	0:5c4d7b2438d3	286	if( grp == NULL )
switches	0:5c4d7b2438d3	287	return;
switches	0:5c4d7b2438d3	288
switches	0:5c4d7b2438d3	289	memset( grp, 0, sizeof( mbedtls_ecp_group ) );
switches	0:5c4d7b2438d3	290	}
switches	0:5c4d7b2438d3	291
switches	0:5c4d7b2438d3	292	/*
switches	0:5c4d7b2438d3	293	* Initialize (the components of) a key pair
switches	0:5c4d7b2438d3	294	*/
switches	0:5c4d7b2438d3	295	void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key )
switches	0:5c4d7b2438d3	296	{
switches	0:5c4d7b2438d3	297	if( key == NULL )
switches	0:5c4d7b2438d3	298	return;
switches	0:5c4d7b2438d3	299
switches	0:5c4d7b2438d3	300	mbedtls_ecp_group_init( &key->grp );
switches	0:5c4d7b2438d3	301	mbedtls_mpi_init( &key->d );
switches	0:5c4d7b2438d3	302	mbedtls_ecp_point_init( &key->Q );
switches	0:5c4d7b2438d3	303	}
switches	0:5c4d7b2438d3	304
switches	0:5c4d7b2438d3	305	/*
switches	0:5c4d7b2438d3	306	* Unallocate (the components of) a point
switches	0:5c4d7b2438d3	307	*/
switches	0:5c4d7b2438d3	308	void mbedtls_ecp_point_free( mbedtls_ecp_point *pt )
switches	0:5c4d7b2438d3	309	{
switches	0:5c4d7b2438d3	310	if( pt == NULL )
switches	0:5c4d7b2438d3	311	return;
switches	0:5c4d7b2438d3	312
switches	0:5c4d7b2438d3	313	mbedtls_mpi_free( &( pt->X ) );
switches	0:5c4d7b2438d3	314	mbedtls_mpi_free( &( pt->Y ) );
switches	0:5c4d7b2438d3	315	mbedtls_mpi_free( &( pt->Z ) );
switches	0:5c4d7b2438d3	316	}
switches	0:5c4d7b2438d3	317
switches	0:5c4d7b2438d3	318	/*
switches	0:5c4d7b2438d3	319	* Unallocate (the components of) a group
switches	0:5c4d7b2438d3	320	*/
switches	0:5c4d7b2438d3	321	void mbedtls_ecp_group_free( mbedtls_ecp_group *grp )
switches	0:5c4d7b2438d3	322	{
switches	0:5c4d7b2438d3	323	size_t i;
switches	0:5c4d7b2438d3	324
switches	0:5c4d7b2438d3	325	if( grp == NULL )
switches	0:5c4d7b2438d3	326	return;
switches	0:5c4d7b2438d3	327
switches	0:5c4d7b2438d3	328	if( grp->h != 1 )
switches	0:5c4d7b2438d3	329	{
switches	0:5c4d7b2438d3	330	mbedtls_mpi_free( &grp->P );
switches	0:5c4d7b2438d3	331	mbedtls_mpi_free( &grp->A );
switches	0:5c4d7b2438d3	332	mbedtls_mpi_free( &grp->B );
switches	0:5c4d7b2438d3	333	mbedtls_ecp_point_free( &grp->G );
switches	0:5c4d7b2438d3	334	mbedtls_mpi_free( &grp->N );
switches	0:5c4d7b2438d3	335	}
switches	0:5c4d7b2438d3	336
switches	0:5c4d7b2438d3	337	if( grp->T != NULL )
switches	0:5c4d7b2438d3	338	{
switches	0:5c4d7b2438d3	339	for( i = 0; i < grp->T_size; i++ )
switches	0:5c4d7b2438d3	340	mbedtls_ecp_point_free( &grp->T[i] );
switches	0:5c4d7b2438d3	341	mbedtls_free( grp->T );
switches	0:5c4d7b2438d3	342	}
switches	0:5c4d7b2438d3	343
switches	0:5c4d7b2438d3	344	mbedtls_zeroize( grp, sizeof( mbedtls_ecp_group ) );
switches	0:5c4d7b2438d3	345	}
switches	0:5c4d7b2438d3	346
switches	0:5c4d7b2438d3	347	/*
switches	0:5c4d7b2438d3	348	* Unallocate (the components of) a key pair
switches	0:5c4d7b2438d3	349	*/
switches	0:5c4d7b2438d3	350	void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key )
switches	0:5c4d7b2438d3	351	{
switches	0:5c4d7b2438d3	352	if( key == NULL )
switches	0:5c4d7b2438d3	353	return;
switches	0:5c4d7b2438d3	354
switches	0:5c4d7b2438d3	355	mbedtls_ecp_group_free( &key->grp );
switches	0:5c4d7b2438d3	356	mbedtls_mpi_free( &key->d );
switches	0:5c4d7b2438d3	357	mbedtls_ecp_point_free( &key->Q );
switches	0:5c4d7b2438d3	358	}
switches	0:5c4d7b2438d3	359
switches	0:5c4d7b2438d3	360	/*
switches	0:5c4d7b2438d3	361	* Copy the contents of a point
switches	0:5c4d7b2438d3	362	*/
switches	0:5c4d7b2438d3	363	int mbedtls_ecp_copy( mbedtls_ecp_point P, const mbedtls_ecp_point Q )
switches	0:5c4d7b2438d3	364	{
switches	0:5c4d7b2438d3	365	int ret;
switches	0:5c4d7b2438d3	366
switches	0:5c4d7b2438d3	367	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->X, &Q->X ) );
switches	0:5c4d7b2438d3	368	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->Y, &Q->Y ) );
switches	0:5c4d7b2438d3	369	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->Z, &Q->Z ) );
switches	0:5c4d7b2438d3	370
switches	0:5c4d7b2438d3	371	cleanup:
switches	0:5c4d7b2438d3	372	return( ret );
switches	0:5c4d7b2438d3	373	}
switches	0:5c4d7b2438d3	374
switches	0:5c4d7b2438d3	375	/*
switches	0:5c4d7b2438d3	376	* Copy the contents of a group object
switches	0:5c4d7b2438d3	377	*/
switches	0:5c4d7b2438d3	378	int mbedtls_ecp_group_copy( mbedtls_ecp_group dst, const mbedtls_ecp_group src )
switches	0:5c4d7b2438d3	379	{
switches	0:5c4d7b2438d3	380	return mbedtls_ecp_group_load( dst, src->id );
switches	0:5c4d7b2438d3	381	}
switches	0:5c4d7b2438d3	382
switches	0:5c4d7b2438d3	383	/*
switches	0:5c4d7b2438d3	384	* Set point to zero
switches	0:5c4d7b2438d3	385	*/
switches	0:5c4d7b2438d3	386	int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt )
switches	0:5c4d7b2438d3	387	{
switches	0:5c4d7b2438d3	388	int ret;
switches	0:5c4d7b2438d3	389
switches	0:5c4d7b2438d3	390	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->X , 1 ) );
switches	0:5c4d7b2438d3	391	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Y , 1 ) );
switches	0:5c4d7b2438d3	392	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Z , 0 ) );
switches	0:5c4d7b2438d3	393
switches	0:5c4d7b2438d3	394	cleanup:
switches	0:5c4d7b2438d3	395	return( ret );
switches	0:5c4d7b2438d3	396	}
switches	0:5c4d7b2438d3	397
switches	0:5c4d7b2438d3	398	/*
switches	0:5c4d7b2438d3	399	* Tell if a point is zero
switches	0:5c4d7b2438d3	400	*/
switches	0:5c4d7b2438d3	401	int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt )
switches	0:5c4d7b2438d3	402	{
switches	0:5c4d7b2438d3	403	return( mbedtls_mpi_cmp_int( &pt->Z, 0 ) == 0 );
switches	0:5c4d7b2438d3	404	}
switches	0:5c4d7b2438d3	405
switches	0:5c4d7b2438d3	406	/*
switches	0:5c4d7b2438d3	407	* Compare two points lazyly
switches	0:5c4d7b2438d3	408	*/
switches	0:5c4d7b2438d3	409	int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P,
switches	0:5c4d7b2438d3	410	const mbedtls_ecp_point *Q )
switches	0:5c4d7b2438d3	411	{
switches	0:5c4d7b2438d3	412	if( mbedtls_mpi_cmp_mpi( &P->X, &Q->X ) == 0 &&
switches	0:5c4d7b2438d3	413	mbedtls_mpi_cmp_mpi( &P->Y, &Q->Y ) == 0 &&
switches	0:5c4d7b2438d3	414	mbedtls_mpi_cmp_mpi( &P->Z, &Q->Z ) == 0 )
switches	0:5c4d7b2438d3	415	{
switches	0:5c4d7b2438d3	416	return( 0 );
switches	0:5c4d7b2438d3	417	}
switches	0:5c4d7b2438d3	418
switches	0:5c4d7b2438d3	419	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	420	}
switches	0:5c4d7b2438d3	421
switches	0:5c4d7b2438d3	422	/*
switches	0:5c4d7b2438d3	423	* Import a non-zero point from ASCII strings
switches	0:5c4d7b2438d3	424	*/
switches	0:5c4d7b2438d3	425	int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix,
switches	0:5c4d7b2438d3	426	const char x, const char y )
switches	0:5c4d7b2438d3	427	{
switches	0:5c4d7b2438d3	428	int ret;
switches	0:5c4d7b2438d3	429
switches	0:5c4d7b2438d3	430	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->X, radix, x ) );
switches	0:5c4d7b2438d3	431	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->Y, radix, y ) );
switches	0:5c4d7b2438d3	432	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &P->Z, 1 ) );
switches	0:5c4d7b2438d3	433
switches	0:5c4d7b2438d3	434	cleanup:
switches	0:5c4d7b2438d3	435	return( ret );
switches	0:5c4d7b2438d3	436	}
switches	0:5c4d7b2438d3	437
switches	0:5c4d7b2438d3	438	/*
switches	0:5c4d7b2438d3	439	* Export a point into unsigned binary data (SEC1 2.3.3)
switches	0:5c4d7b2438d3	440	*/
switches	0:5c4d7b2438d3	441	int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group grp, const mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	442	int format, size_t *olen,
switches	0:5c4d7b2438d3	443	unsigned char *buf, size_t buflen )
switches	0:5c4d7b2438d3	444	{
switches	0:5c4d7b2438d3	445	int ret = 0;
switches	0:5c4d7b2438d3	446	size_t plen;
switches	0:5c4d7b2438d3	447
switches	0:5c4d7b2438d3	448	if( format != MBEDTLS_ECP_PF_UNCOMPRESSED &&
switches	0:5c4d7b2438d3	449	format != MBEDTLS_ECP_PF_COMPRESSED )
switches	0:5c4d7b2438d3	450	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	451
switches	0:5c4d7b2438d3	452	/*
switches	0:5c4d7b2438d3	453	* Common case: P == 0
switches	0:5c4d7b2438d3	454	*/
switches	0:5c4d7b2438d3	455	if( mbedtls_mpi_cmp_int( &P->Z, 0 ) == 0 )
switches	0:5c4d7b2438d3	456	{
switches	0:5c4d7b2438d3	457	if( buflen < 1 )
switches	0:5c4d7b2438d3	458	return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
switches	0:5c4d7b2438d3	459
switches	0:5c4d7b2438d3	460	buf[0] = 0x00;
switches	0:5c4d7b2438d3	461	*olen = 1;
switches	0:5c4d7b2438d3	462
switches	0:5c4d7b2438d3	463	return( 0 );
switches	0:5c4d7b2438d3	464	}
switches	0:5c4d7b2438d3	465
switches	0:5c4d7b2438d3	466	plen = mbedtls_mpi_size( &grp->P );
switches	0:5c4d7b2438d3	467
switches	0:5c4d7b2438d3	468	if( format == MBEDTLS_ECP_PF_UNCOMPRESSED )
switches	0:5c4d7b2438d3	469	{
switches	0:5c4d7b2438d3	470	olen = 2 plen + 1;
switches	0:5c4d7b2438d3	471
switches	0:5c4d7b2438d3	472	if( buflen < *olen )
switches	0:5c4d7b2438d3	473	return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
switches	0:5c4d7b2438d3	474
switches	0:5c4d7b2438d3	475	buf[0] = 0x04;
switches	0:5c4d7b2438d3	476	MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &P->X, buf + 1, plen ) );
switches	0:5c4d7b2438d3	477	MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &P->Y, buf + 1 + plen, plen ) );
switches	0:5c4d7b2438d3	478	}
switches	0:5c4d7b2438d3	479	else if( format == MBEDTLS_ECP_PF_COMPRESSED )
switches	0:5c4d7b2438d3	480	{
switches	0:5c4d7b2438d3	481	*olen = plen + 1;
switches	0:5c4d7b2438d3	482
switches	0:5c4d7b2438d3	483	if( buflen < *olen )
switches	0:5c4d7b2438d3	484	return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
switches	0:5c4d7b2438d3	485
switches	0:5c4d7b2438d3	486	buf[0] = 0x02 + mbedtls_mpi_get_bit( &P->Y, 0 );
switches	0:5c4d7b2438d3	487	MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &P->X, buf + 1, plen ) );
switches	0:5c4d7b2438d3	488	}
switches	0:5c4d7b2438d3	489
switches	0:5c4d7b2438d3	490	cleanup:
switches	0:5c4d7b2438d3	491	return( ret );
switches	0:5c4d7b2438d3	492	}
switches	0:5c4d7b2438d3	493
switches	0:5c4d7b2438d3	494	/*
switches	0:5c4d7b2438d3	495	* Import a point from unsigned binary data (SEC1 2.3.4)
switches	0:5c4d7b2438d3	496	*/
switches	0:5c4d7b2438d3	497	int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group grp, mbedtls_ecp_point pt,
switches	0:5c4d7b2438d3	498	const unsigned char *buf, size_t ilen )
switches	0:5c4d7b2438d3	499	{
switches	0:5c4d7b2438d3	500	int ret;
switches	0:5c4d7b2438d3	501	size_t plen;
switches	0:5c4d7b2438d3	502
switches	0:5c4d7b2438d3	503	if( ilen < 1 )
switches	0:5c4d7b2438d3	504	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	505
switches	0:5c4d7b2438d3	506	if( buf[0] == 0x00 )
switches	0:5c4d7b2438d3	507	{
switches	0:5c4d7b2438d3	508	if( ilen == 1 )
switches	0:5c4d7b2438d3	509	return( mbedtls_ecp_set_zero( pt ) );
switches	0:5c4d7b2438d3	510	else
switches	0:5c4d7b2438d3	511	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	512	}
switches	0:5c4d7b2438d3	513
switches	0:5c4d7b2438d3	514	plen = mbedtls_mpi_size( &grp->P );
switches	0:5c4d7b2438d3	515
switches	0:5c4d7b2438d3	516	if( buf[0] != 0x04 )
switches	0:5c4d7b2438d3	517	return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
switches	0:5c4d7b2438d3	518
switches	0:5c4d7b2438d3	519	if( ilen != 2 * plen + 1 )
switches	0:5c4d7b2438d3	520	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	521
switches	0:5c4d7b2438d3	522	MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &pt->X, buf + 1, plen ) );
switches	0:5c4d7b2438d3	523	MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &pt->Y, buf + 1 + plen, plen ) );
switches	0:5c4d7b2438d3	524	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Z, 1 ) );
switches	0:5c4d7b2438d3	525
switches	0:5c4d7b2438d3	526	cleanup:
switches	0:5c4d7b2438d3	527	return( ret );
switches	0:5c4d7b2438d3	528	}
switches	0:5c4d7b2438d3	529
switches	0:5c4d7b2438d3	530	/*
switches	0:5c4d7b2438d3	531	* Import a point from a TLS ECPoint record (RFC 4492)
switches	0:5c4d7b2438d3	532	* struct {
switches	0:5c4d7b2438d3	533	* opaque point <1..2^8-1>;
switches	0:5c4d7b2438d3	534	* } ECPoint;
switches	0:5c4d7b2438d3	535	*/
switches	0:5c4d7b2438d3	536	int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group grp, mbedtls_ecp_point pt,
switches	0:5c4d7b2438d3	537	const unsigned char **buf, size_t buf_len )
switches	0:5c4d7b2438d3	538	{
switches	0:5c4d7b2438d3	539	unsigned char data_len;
switches	0:5c4d7b2438d3	540	const unsigned char *buf_start;
switches	0:5c4d7b2438d3	541
switches	0:5c4d7b2438d3	542	/*
switches	0:5c4d7b2438d3	543	* We must have at least two bytes (1 for length, at least one for data)
switches	0:5c4d7b2438d3	544	*/
switches	0:5c4d7b2438d3	545	if( buf_len < 2 )
switches	0:5c4d7b2438d3	546	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	547
switches	0:5c4d7b2438d3	548	data_len = (buf)++;
switches	0:5c4d7b2438d3	549	if( data_len < 1 \|\| data_len > buf_len - 1 )
switches	0:5c4d7b2438d3	550	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	551
switches	0:5c4d7b2438d3	552	/*
switches	0:5c4d7b2438d3	553	* Save buffer start for read_binary and update buf
switches	0:5c4d7b2438d3	554	*/
switches	0:5c4d7b2438d3	555	buf_start = *buf;
switches	0:5c4d7b2438d3	556	*buf += data_len;
switches	0:5c4d7b2438d3	557
switches	0:5c4d7b2438d3	558	return mbedtls_ecp_point_read_binary( grp, pt, buf_start, data_len );
switches	0:5c4d7b2438d3	559	}
switches	0:5c4d7b2438d3	560
switches	0:5c4d7b2438d3	561	/*
switches	0:5c4d7b2438d3	562	* Export a point as a TLS ECPoint record (RFC 4492)
switches	0:5c4d7b2438d3	563	* struct {
switches	0:5c4d7b2438d3	564	* opaque point <1..2^8-1>;
switches	0:5c4d7b2438d3	565	* } ECPoint;
switches	0:5c4d7b2438d3	566	*/
switches	0:5c4d7b2438d3	567	int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group grp, const mbedtls_ecp_point pt,
switches	0:5c4d7b2438d3	568	int format, size_t *olen,
switches	0:5c4d7b2438d3	569	unsigned char *buf, size_t blen )
switches	0:5c4d7b2438d3	570	{
switches	0:5c4d7b2438d3	571	int ret;
switches	0:5c4d7b2438d3	572
switches	0:5c4d7b2438d3	573	/*
switches	0:5c4d7b2438d3	574	* buffer length must be at least one, for our length byte
switches	0:5c4d7b2438d3	575	*/
switches	0:5c4d7b2438d3	576	if( blen < 1 )
switches	0:5c4d7b2438d3	577	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	578
switches	0:5c4d7b2438d3	579	if( ( ret = mbedtls_ecp_point_write_binary( grp, pt, format,
switches	0:5c4d7b2438d3	580	olen, buf + 1, blen - 1) ) != 0 )
switches	0:5c4d7b2438d3	581	return( ret );
switches	0:5c4d7b2438d3	582
switches	0:5c4d7b2438d3	583	/*
switches	0:5c4d7b2438d3	584	* write length to the first byte and update total length
switches	0:5c4d7b2438d3	585	*/
switches	0:5c4d7b2438d3	586	buf[0] = (unsigned char) *olen;
switches	0:5c4d7b2438d3	587	++*olen;
switches	0:5c4d7b2438d3	588
switches	0:5c4d7b2438d3	589	return( 0 );
switches	0:5c4d7b2438d3	590	}
switches	0:5c4d7b2438d3	591
switches	0:5c4d7b2438d3	592	/*
switches	0:5c4d7b2438d3	593	* Set a group from an ECParameters record (RFC 4492)
switches	0:5c4d7b2438d3	594	*/
switches	0:5c4d7b2438d3	595	int mbedtls_ecp_tls_read_group( mbedtls_ecp_group grp, const unsigned char *buf, size_t len )
switches	0:5c4d7b2438d3	596	{
switches	0:5c4d7b2438d3	597	uint16_t tls_id;
switches	0:5c4d7b2438d3	598	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	599
switches	0:5c4d7b2438d3	600	/*
switches	0:5c4d7b2438d3	601	* We expect at least three bytes (see below)
switches	0:5c4d7b2438d3	602	*/
switches	0:5c4d7b2438d3	603	if( len < 3 )
switches	0:5c4d7b2438d3	604	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	605
switches	0:5c4d7b2438d3	606	/*
switches	0:5c4d7b2438d3	607	* First byte is curve_type; only named_curve is handled
switches	0:5c4d7b2438d3	608	*/
switches	0:5c4d7b2438d3	609	if( (buf)++ != MBEDTLS_ECP_TLS_NAMED_CURVE )
switches	0:5c4d7b2438d3	610	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	611
switches	0:5c4d7b2438d3	612	/*
switches	0:5c4d7b2438d3	613	* Next two bytes are the namedcurve value
switches	0:5c4d7b2438d3	614	*/
switches	0:5c4d7b2438d3	615	tls_id = (buf)++;
switches	0:5c4d7b2438d3	616	tls_id <<= 8;
switches	0:5c4d7b2438d3	617	tls_id \|= (buf)++;
switches	0:5c4d7b2438d3	618
switches	0:5c4d7b2438d3	619	if( ( curve_info = mbedtls_ecp_curve_info_from_tls_id( tls_id ) ) == NULL )
switches	0:5c4d7b2438d3	620	return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
switches	0:5c4d7b2438d3	621
switches	0:5c4d7b2438d3	622	return mbedtls_ecp_group_load( grp, curve_info->grp_id );
switches	0:5c4d7b2438d3	623	}
switches	0:5c4d7b2438d3	624
switches	0:5c4d7b2438d3	625	/*
switches	0:5c4d7b2438d3	626	* Write the ECParameters record corresponding to a group (RFC 4492)
switches	0:5c4d7b2438d3	627	*/
switches	0:5c4d7b2438d3	628	int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group grp, size_t olen,
switches	0:5c4d7b2438d3	629	unsigned char *buf, size_t blen )
switches	0:5c4d7b2438d3	630	{
switches	0:5c4d7b2438d3	631	const mbedtls_ecp_curve_info *curve_info;
switches	0:5c4d7b2438d3	632
switches	0:5c4d7b2438d3	633	if( ( curve_info = mbedtls_ecp_curve_info_from_grp_id( grp->id ) ) == NULL )
switches	0:5c4d7b2438d3	634	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	635
switches	0:5c4d7b2438d3	636	/*
switches	0:5c4d7b2438d3	637	* We are going to write 3 bytes (see below)
switches	0:5c4d7b2438d3	638	*/
switches	0:5c4d7b2438d3	639	*olen = 3;
switches	0:5c4d7b2438d3	640	if( blen < *olen )
switches	0:5c4d7b2438d3	641	return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
switches	0:5c4d7b2438d3	642
switches	0:5c4d7b2438d3	643	/*
switches	0:5c4d7b2438d3	644	* First byte is curve_type, always named_curve
switches	0:5c4d7b2438d3	645	*/
switches	0:5c4d7b2438d3	646	*buf++ = MBEDTLS_ECP_TLS_NAMED_CURVE;
switches	0:5c4d7b2438d3	647
switches	0:5c4d7b2438d3	648	/*
switches	0:5c4d7b2438d3	649	* Next two bytes are the namedcurve value
switches	0:5c4d7b2438d3	650	*/
switches	0:5c4d7b2438d3	651	buf[0] = curve_info->tls_id >> 8;
switches	0:5c4d7b2438d3	652	buf[1] = curve_info->tls_id & 0xFF;
switches	0:5c4d7b2438d3	653
switches	0:5c4d7b2438d3	654	return( 0 );
switches	0:5c4d7b2438d3	655	}
switches	0:5c4d7b2438d3	656
switches	0:5c4d7b2438d3	657	/*
switches	0:5c4d7b2438d3	658	* Wrapper around fast quasi-modp functions, with fall-back to mbedtls_mpi_mod_mpi.
switches	0:5c4d7b2438d3	659	* See the documentation of struct mbedtls_ecp_group.
switches	0:5c4d7b2438d3	660	*
switches	0:5c4d7b2438d3	661	* This function is in the critial loop for mbedtls_ecp_mul, so pay attention to perf.
switches	0:5c4d7b2438d3	662	*/
switches	0:5c4d7b2438d3	663	static int ecp_modp( mbedtls_mpi N, const mbedtls_ecp_group grp )
switches	0:5c4d7b2438d3	664	{
switches	0:5c4d7b2438d3	665	int ret;
switches	0:5c4d7b2438d3	666
switches	0:5c4d7b2438d3	667	if( grp->modp == NULL )
switches	0:5c4d7b2438d3	668	return( mbedtls_mpi_mod_mpi( N, N, &grp->P ) );
switches	0:5c4d7b2438d3	669
switches	0:5c4d7b2438d3	670	/* N->s < 0 is a much faster test, which fails only if N is 0 */
switches	0:5c4d7b2438d3	671	if( ( N->s < 0 && mbedtls_mpi_cmp_int( N, 0 ) != 0 ) \|\|
switches	0:5c4d7b2438d3	672	mbedtls_mpi_bitlen( N ) > 2 * grp->pbits )
switches	0:5c4d7b2438d3	673	{
switches	0:5c4d7b2438d3	674	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	675	}
switches	0:5c4d7b2438d3	676
switches	0:5c4d7b2438d3	677	MBEDTLS_MPI_CHK( grp->modp( N ) );
switches	0:5c4d7b2438d3	678
switches	0:5c4d7b2438d3	679	/* N->s < 0 is a much faster test, which fails only if N is 0 */
switches	0:5c4d7b2438d3	680	while( N->s < 0 && mbedtls_mpi_cmp_int( N, 0 ) != 0 )
switches	0:5c4d7b2438d3	681	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( N, N, &grp->P ) );
switches	0:5c4d7b2438d3	682
switches	0:5c4d7b2438d3	683	while( mbedtls_mpi_cmp_mpi( N, &grp->P ) >= 0 )
switches	0:5c4d7b2438d3	684	/* we known P, N and the result are positive */
switches	0:5c4d7b2438d3	685	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( N, N, &grp->P ) );
switches	0:5c4d7b2438d3	686
switches	0:5c4d7b2438d3	687	cleanup:
switches	0:5c4d7b2438d3	688	return( ret );
switches	0:5c4d7b2438d3	689	}
switches	0:5c4d7b2438d3	690
switches	0:5c4d7b2438d3	691	/*
switches	0:5c4d7b2438d3	692	* Fast mod-p functions expect their argument to be in the 0..p^2 range.
switches	0:5c4d7b2438d3	693	*
switches	0:5c4d7b2438d3	694	* In order to guarantee that, we need to ensure that operands of
switches	0:5c4d7b2438d3	695	* mbedtls_mpi_mul_mpi are in the 0..p range. So, after each operation we will
switches	0:5c4d7b2438d3	696	* bring the result back to this range.
switches	0:5c4d7b2438d3	697	*
switches	0:5c4d7b2438d3	698	* The following macros are shortcuts for doing that.
switches	0:5c4d7b2438d3	699	*/
switches	0:5c4d7b2438d3	700
switches	0:5c4d7b2438d3	701	/*
switches	0:5c4d7b2438d3	702	* Reduce a mbedtls_mpi mod p in-place, general case, to use after mbedtls_mpi_mul_mpi
switches	0:5c4d7b2438d3	703	*/
switches	0:5c4d7b2438d3	704	#if defined(MBEDTLS_SELF_TEST)
switches	0:5c4d7b2438d3	705	#define INC_MUL_COUNT mul_count++;
switches	0:5c4d7b2438d3	706	#else
switches	0:5c4d7b2438d3	707	#define INC_MUL_COUNT
switches	0:5c4d7b2438d3	708	#endif
switches	0:5c4d7b2438d3	709
switches	0:5c4d7b2438d3	710	#define MOD_MUL( N ) do { MBEDTLS_MPI_CHK( ecp_modp( &N, grp ) ); INC_MUL_COUNT } \
switches	0:5c4d7b2438d3	711	while( 0 )
switches	0:5c4d7b2438d3	712
switches	0:5c4d7b2438d3	713	/*
switches	0:5c4d7b2438d3	714	* Reduce a mbedtls_mpi mod p in-place, to use after mbedtls_mpi_sub_mpi
switches	0:5c4d7b2438d3	715	* N->s < 0 is a very fast test, which fails only if N is 0
switches	0:5c4d7b2438d3	716	*/
switches	0:5c4d7b2438d3	717	#define MOD_SUB( N ) \
switches	0:5c4d7b2438d3	718	while( N.s < 0 && mbedtls_mpi_cmp_int( &N, 0 ) != 0 ) \
switches	0:5c4d7b2438d3	719	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &N, &N, &grp->P ) )
switches	0:5c4d7b2438d3	720
switches	0:5c4d7b2438d3	721	/*
switches	0:5c4d7b2438d3	722	* Reduce a mbedtls_mpi mod p in-place, to use after mbedtls_mpi_add_mpi and mbedtls_mpi_mul_int.
switches	0:5c4d7b2438d3	723	* We known P, N and the result are positive, so sub_abs is correct, and
switches	0:5c4d7b2438d3	724	* a bit faster.
switches	0:5c4d7b2438d3	725	*/
switches	0:5c4d7b2438d3	726	#define MOD_ADD( N ) \
switches	0:5c4d7b2438d3	727	while( mbedtls_mpi_cmp_mpi( &N, &grp->P ) >= 0 ) \
switches	0:5c4d7b2438d3	728	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( &N, &N, &grp->P ) )
switches	0:5c4d7b2438d3	729
switches	0:5c4d7b2438d3	730	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	731	/*
switches	0:5c4d7b2438d3	732	* For curves in short Weierstrass form, we do all the internal operations in
switches	0:5c4d7b2438d3	733	* Jacobian coordinates.
switches	0:5c4d7b2438d3	734	*
switches	0:5c4d7b2438d3	735	* For multiplication, we'll use a comb method with coutermeasueres against
switches	0:5c4d7b2438d3	736	* SPA, hence timing attacks.
switches	0:5c4d7b2438d3	737	*/
switches	0:5c4d7b2438d3	738
switches	0:5c4d7b2438d3	739	/*
switches	0:5c4d7b2438d3	740	* Normalize jacobian coordinates so that Z == 0 \|\| Z == 1 (GECC 3.2.1)
switches	0:5c4d7b2438d3	741	* Cost: 1N := 1I + 3M + 1S
switches	0:5c4d7b2438d3	742	*/
switches	0:5c4d7b2438d3	743	static int ecp_normalize_jac( const mbedtls_ecp_group grp, mbedtls_ecp_point pt )
switches	0:5c4d7b2438d3	744	{
switches	0:5c4d7b2438d3	745	int ret;
switches	0:5c4d7b2438d3	746	mbedtls_mpi Zi, ZZi;
switches	0:5c4d7b2438d3	747
switches	0:5c4d7b2438d3	748	if( mbedtls_mpi_cmp_int( &pt->Z, 0 ) == 0 )
switches	0:5c4d7b2438d3	749	return( 0 );
switches	0:5c4d7b2438d3	750
switches	0:5c4d7b2438d3	751	mbedtls_mpi_init( &Zi ); mbedtls_mpi_init( &ZZi );
switches	0:5c4d7b2438d3	752
switches	0:5c4d7b2438d3	753	/*
switches	0:5c4d7b2438d3	754	* X = X / Z^2 mod p
switches	0:5c4d7b2438d3	755	*/
switches	0:5c4d7b2438d3	756	MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &Zi, &pt->Z, &grp->P ) );
switches	0:5c4d7b2438d3	757	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ZZi, &Zi, &Zi ) ); MOD_MUL( ZZi );
switches	0:5c4d7b2438d3	758	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->X, &pt->X, &ZZi ) ); MOD_MUL( pt->X );
switches	0:5c4d7b2438d3	759
switches	0:5c4d7b2438d3	760	/*
switches	0:5c4d7b2438d3	761	* Y = Y / Z^3 mod p
switches	0:5c4d7b2438d3	762	*/
switches	0:5c4d7b2438d3	763	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->Y, &pt->Y, &ZZi ) ); MOD_MUL( pt->Y );
switches	0:5c4d7b2438d3	764	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->Y, &pt->Y, &Zi ) ); MOD_MUL( pt->Y );
switches	0:5c4d7b2438d3	765
switches	0:5c4d7b2438d3	766	/*
switches	0:5c4d7b2438d3	767	* Z = 1
switches	0:5c4d7b2438d3	768	*/
switches	0:5c4d7b2438d3	769	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Z, 1 ) );
switches	0:5c4d7b2438d3	770
switches	0:5c4d7b2438d3	771	cleanup:
switches	0:5c4d7b2438d3	772
switches	0:5c4d7b2438d3	773	mbedtls_mpi_free( &Zi ); mbedtls_mpi_free( &ZZi );
switches	0:5c4d7b2438d3	774
switches	0:5c4d7b2438d3	775	return( ret );
switches	0:5c4d7b2438d3	776	}
switches	0:5c4d7b2438d3	777
switches	0:5c4d7b2438d3	778	/*
switches	0:5c4d7b2438d3	779	* Normalize jacobian coordinates of an array of (pointers to) points,
switches	0:5c4d7b2438d3	780	* using Montgomery's trick to perform only one inversion mod P.
switches	0:5c4d7b2438d3	781	* (See for example Cohen's "A Course in Computational Algebraic Number
switches	0:5c4d7b2438d3	782	* Theory", Algorithm 10.3.4.)
switches	0:5c4d7b2438d3	783	*
switches	0:5c4d7b2438d3	784	* Warning: fails (returning an error) if one of the points is zero!
switches	0:5c4d7b2438d3	785	* This should never happen, see choice of w in ecp_mul_comb().
switches	0:5c4d7b2438d3	786	*
switches	0:5c4d7b2438d3	787	* Cost: 1N(t) := 1I + (6t - 3)M + 1S
switches	0:5c4d7b2438d3	788	*/
switches	0:5c4d7b2438d3	789	static int ecp_normalize_jac_many( const mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	790	mbedtls_ecp_point *T[], size_t t_len )
switches	0:5c4d7b2438d3	791	{
switches	0:5c4d7b2438d3	792	int ret;
switches	0:5c4d7b2438d3	793	size_t i;
switches	0:5c4d7b2438d3	794	mbedtls_mpi *c, u, Zi, ZZi;
switches	0:5c4d7b2438d3	795
switches	0:5c4d7b2438d3	796	if( t_len < 2 )
switches	0:5c4d7b2438d3	797	return( ecp_normalize_jac( grp, *T ) );
switches	0:5c4d7b2438d3	798
switches	0:5c4d7b2438d3	799	if( ( c = mbedtls_calloc( t_len, sizeof( mbedtls_mpi ) ) ) == NULL )
switches	0:5c4d7b2438d3	800	return( MBEDTLS_ERR_ECP_ALLOC_FAILED );
switches	0:5c4d7b2438d3	801
switches	0:5c4d7b2438d3	802	mbedtls_mpi_init( &u ); mbedtls_mpi_init( &Zi ); mbedtls_mpi_init( &ZZi );
switches	0:5c4d7b2438d3	803
switches	0:5c4d7b2438d3	804	/*
switches	0:5c4d7b2438d3	805	* c[i] = Z_0 * ... * Z_i
switches	0:5c4d7b2438d3	806	*/
switches	0:5c4d7b2438d3	807	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &c[0], &T[0]->Z ) );
switches	0:5c4d7b2438d3	808	for( i = 1; i < t_len; i++ )
switches	0:5c4d7b2438d3	809	{
switches	0:5c4d7b2438d3	810	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &c[i], &c[i-1], &T[i]->Z ) );
switches	0:5c4d7b2438d3	811	MOD_MUL( c[i] );
switches	0:5c4d7b2438d3	812	}
switches	0:5c4d7b2438d3	813
switches	0:5c4d7b2438d3	814	/*
switches	0:5c4d7b2438d3	815	* u = 1 / (Z_0 * ... * Z_n) mod P
switches	0:5c4d7b2438d3	816	*/
switches	0:5c4d7b2438d3	817	MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &u, &c[t_len-1], &grp->P ) );
switches	0:5c4d7b2438d3	818
switches	0:5c4d7b2438d3	819	for( i = t_len - 1; ; i-- )
switches	0:5c4d7b2438d3	820	{
switches	0:5c4d7b2438d3	821	/*
switches	0:5c4d7b2438d3	822	* Zi = 1 / Z_i mod p
switches	0:5c4d7b2438d3	823	* u = 1 / (Z_0 * ... * Z_i) mod P
switches	0:5c4d7b2438d3	824	*/
switches	0:5c4d7b2438d3	825	if( i == 0 ) {
switches	0:5c4d7b2438d3	826	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &Zi, &u ) );
switches	0:5c4d7b2438d3	827	}
switches	0:5c4d7b2438d3	828	else
switches	0:5c4d7b2438d3	829	{
switches	0:5c4d7b2438d3	830	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &Zi, &u, &c[i-1] ) ); MOD_MUL( Zi );
switches	0:5c4d7b2438d3	831	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &u, &u, &T[i]->Z ) ); MOD_MUL( u );
switches	0:5c4d7b2438d3	832	}
switches	0:5c4d7b2438d3	833
switches	0:5c4d7b2438d3	834	/*
switches	0:5c4d7b2438d3	835	* proceed as in normalize()
switches	0:5c4d7b2438d3	836	*/
switches	0:5c4d7b2438d3	837	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ZZi, &Zi, &Zi ) ); MOD_MUL( ZZi );
switches	0:5c4d7b2438d3	838	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T[i]->X, &T[i]->X, &ZZi ) ); MOD_MUL( T[i]->X );
switches	0:5c4d7b2438d3	839	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &ZZi ) ); MOD_MUL( T[i]->Y );
switches	0:5c4d7b2438d3	840	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T[i]->Y, &T[i]->Y, &Zi ) ); MOD_MUL( T[i]->Y );
switches	0:5c4d7b2438d3	841
switches	0:5c4d7b2438d3	842	/*
switches	0:5c4d7b2438d3	843	* Post-precessing: reclaim some memory by shrinking coordinates
switches	0:5c4d7b2438d3	844	* - not storing Z (always 1)
switches	0:5c4d7b2438d3	845	* - shrinking other coordinates, but still keeping the same number of
switches	0:5c4d7b2438d3	846	* limbs as P, as otherwise it will too likely be regrown too fast.
switches	0:5c4d7b2438d3	847	*/
switches	0:5c4d7b2438d3	848	MBEDTLS_MPI_CHK( mbedtls_mpi_shrink( &T[i]->X, grp->P.n ) );
switches	0:5c4d7b2438d3	849	MBEDTLS_MPI_CHK( mbedtls_mpi_shrink( &T[i]->Y, grp->P.n ) );
switches	0:5c4d7b2438d3	850	mbedtls_mpi_free( &T[i]->Z );
switches	0:5c4d7b2438d3	851
switches	0:5c4d7b2438d3	852	if( i == 0 )
switches	0:5c4d7b2438d3	853	break;
switches	0:5c4d7b2438d3	854	}
switches	0:5c4d7b2438d3	855
switches	0:5c4d7b2438d3	856	cleanup:
switches	0:5c4d7b2438d3	857
switches	0:5c4d7b2438d3	858	mbedtls_mpi_free( &u ); mbedtls_mpi_free( &Zi ); mbedtls_mpi_free( &ZZi );
switches	0:5c4d7b2438d3	859	for( i = 0; i < t_len; i++ )
switches	0:5c4d7b2438d3	860	mbedtls_mpi_free( &c[i] );
switches	0:5c4d7b2438d3	861	mbedtls_free( c );
switches	0:5c4d7b2438d3	862
switches	0:5c4d7b2438d3	863	return( ret );
switches	0:5c4d7b2438d3	864	}
switches	0:5c4d7b2438d3	865
switches	0:5c4d7b2438d3	866	/*
switches	0:5c4d7b2438d3	867	* Conditional point inversion: Q -> -Q = (Q.X, -Q.Y, Q.Z) without leak.
switches	0:5c4d7b2438d3	868	* "inv" must be 0 (don't invert) or 1 (invert) or the result will be invalid
switches	0:5c4d7b2438d3	869	*/
switches	0:5c4d7b2438d3	870	static int ecp_safe_invert_jac( const mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	871	mbedtls_ecp_point *Q,
switches	0:5c4d7b2438d3	872	unsigned char inv )
switches	0:5c4d7b2438d3	873	{
switches	0:5c4d7b2438d3	874	int ret;
switches	0:5c4d7b2438d3	875	unsigned char nonzero;
switches	0:5c4d7b2438d3	876	mbedtls_mpi mQY;
switches	0:5c4d7b2438d3	877
switches	0:5c4d7b2438d3	878	mbedtls_mpi_init( &mQY );
switches	0:5c4d7b2438d3	879
switches	0:5c4d7b2438d3	880	/* Use the fact that -Q.Y mod P = P - Q.Y unless Q.Y == 0 */
switches	0:5c4d7b2438d3	881	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &mQY, &grp->P, &Q->Y ) );
switches	0:5c4d7b2438d3	882	nonzero = mbedtls_mpi_cmp_int( &Q->Y, 0 ) != 0;
switches	0:5c4d7b2438d3	883	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_assign( &Q->Y, &mQY, inv & nonzero ) );
switches	0:5c4d7b2438d3	884
switches	0:5c4d7b2438d3	885	cleanup:
switches	0:5c4d7b2438d3	886	mbedtls_mpi_free( &mQY );
switches	0:5c4d7b2438d3	887
switches	0:5c4d7b2438d3	888	return( ret );
switches	0:5c4d7b2438d3	889	}
switches	0:5c4d7b2438d3	890
switches	0:5c4d7b2438d3	891	/*
switches	0:5c4d7b2438d3	892	* Point doubling R = 2 P, Jacobian coordinates
switches	0:5c4d7b2438d3	893	*
switches	0:5c4d7b2438d3	894	* Based on http://www.hyperelliptic.org/EFD/g1p/auto-shortw-jacobian.html#doubling-dbl-1998-cmo-2 .
switches	0:5c4d7b2438d3	895	*
switches	0:5c4d7b2438d3	896	* We follow the variable naming fairly closely. The formula variations that trade a MUL for a SQR
switches	0:5c4d7b2438d3	897	* (plus a few ADDs) aren't useful as our bignum implementation doesn't distinguish squaring.
switches	0:5c4d7b2438d3	898	*
switches	0:5c4d7b2438d3	899	* Standard optimizations are applied when curve parameter A is one of { 0, -3 }.
switches	0:5c4d7b2438d3	900	*
switches	0:5c4d7b2438d3	901	* Cost: 1D := 3M + 4S (A == 0)
switches	0:5c4d7b2438d3	902	* 4M + 4S (A == -3)
switches	0:5c4d7b2438d3	903	* 3M + 6S + 1a otherwise
switches	0:5c4d7b2438d3	904	*/
switches	0:5c4d7b2438d3	905	static int ecp_double_jac( const mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	906	const mbedtls_ecp_point *P )
switches	0:5c4d7b2438d3	907	{
switches	0:5c4d7b2438d3	908	int ret;
switches	0:5c4d7b2438d3	909	mbedtls_mpi M, S, T, U;
switches	0:5c4d7b2438d3	910
switches	0:5c4d7b2438d3	911	#if defined(MBEDTLS_SELF_TEST)
switches	0:5c4d7b2438d3	912	dbl_count++;
switches	0:5c4d7b2438d3	913	#endif
switches	0:5c4d7b2438d3	914
switches	0:5c4d7b2438d3	915	mbedtls_mpi_init( &M ); mbedtls_mpi_init( &S ); mbedtls_mpi_init( &T ); mbedtls_mpi_init( &U );
switches	0:5c4d7b2438d3	916
switches	0:5c4d7b2438d3	917	/* Special case for A = -3 */
switches	0:5c4d7b2438d3	918	if( grp->A.p == NULL )
switches	0:5c4d7b2438d3	919	{
switches	0:5c4d7b2438d3	920	/* M = 3(X + Z^2)(X - Z^2) */
switches	0:5c4d7b2438d3	921	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &P->Z, &P->Z ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	922	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &P->X, &S ) ); MOD_ADD( T );
switches	0:5c4d7b2438d3	923	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &U, &P->X, &S ) ); MOD_SUB( U );
switches	0:5c4d7b2438d3	924	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &T, &U ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	925	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &M, &S, 3 ) ); MOD_ADD( M );
switches	0:5c4d7b2438d3	926	}
switches	0:5c4d7b2438d3	927	else
switches	0:5c4d7b2438d3	928	{
switches	0:5c4d7b2438d3	929	/* M = 3.X^2 */
switches	0:5c4d7b2438d3	930	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &P->X, &P->X ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	931	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &M, &S, 3 ) ); MOD_ADD( M );
switches	0:5c4d7b2438d3	932
switches	0:5c4d7b2438d3	933	/* Optimize away for "koblitz" curves with A = 0 */
switches	0:5c4d7b2438d3	934	if( mbedtls_mpi_cmp_int( &grp->A, 0 ) != 0 )
switches	0:5c4d7b2438d3	935	{
switches	0:5c4d7b2438d3	936	/* M += A.Z^4 */
switches	0:5c4d7b2438d3	937	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &P->Z, &P->Z ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	938	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &S, &S ) ); MOD_MUL( T );
switches	0:5c4d7b2438d3	939	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &T, &grp->A ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	940	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &M, &M, &S ) ); MOD_ADD( M );
switches	0:5c4d7b2438d3	941	}
switches	0:5c4d7b2438d3	942	}
switches	0:5c4d7b2438d3	943
switches	0:5c4d7b2438d3	944	/* S = 4.X.Y^2 */
switches	0:5c4d7b2438d3	945	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &P->Y, &P->Y ) ); MOD_MUL( T );
switches	0:5c4d7b2438d3	946	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &T, 1 ) ); MOD_ADD( T );
switches	0:5c4d7b2438d3	947	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &P->X, &T ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	948	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &S, 1 ) ); MOD_ADD( S );
switches	0:5c4d7b2438d3	949
switches	0:5c4d7b2438d3	950	/* U = 8.Y^4 */
switches	0:5c4d7b2438d3	951	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &U, &T, &T ) ); MOD_MUL( U );
switches	0:5c4d7b2438d3	952	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &U, 1 ) ); MOD_ADD( U );
switches	0:5c4d7b2438d3	953
switches	0:5c4d7b2438d3	954	/* T = M^2 - 2.S */
switches	0:5c4d7b2438d3	955	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &M, &M ) ); MOD_MUL( T );
switches	0:5c4d7b2438d3	956	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &T, &S ) ); MOD_SUB( T );
switches	0:5c4d7b2438d3	957	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &T, &S ) ); MOD_SUB( T );
switches	0:5c4d7b2438d3	958
switches	0:5c4d7b2438d3	959	/* S = M(S - T) - U */
switches	0:5c4d7b2438d3	960	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &S, &S, &T ) ); MOD_SUB( S );
switches	0:5c4d7b2438d3	961	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S, &S, &M ) ); MOD_MUL( S );
switches	0:5c4d7b2438d3	962	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &S, &S, &U ) ); MOD_SUB( S );
switches	0:5c4d7b2438d3	963
switches	0:5c4d7b2438d3	964	/* U = 2.Y.Z */
switches	0:5c4d7b2438d3	965	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &U, &P->Y, &P->Z ) ); MOD_MUL( U );
switches	0:5c4d7b2438d3	966	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &U, 1 ) ); MOD_ADD( U );
switches	0:5c4d7b2438d3	967
switches	0:5c4d7b2438d3	968	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->X, &T ) );
switches	0:5c4d7b2438d3	969	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->Y, &S ) );
switches	0:5c4d7b2438d3	970	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->Z, &U ) );
switches	0:5c4d7b2438d3	971
switches	0:5c4d7b2438d3	972	cleanup:
switches	0:5c4d7b2438d3	973	mbedtls_mpi_free( &M ); mbedtls_mpi_free( &S ); mbedtls_mpi_free( &T ); mbedtls_mpi_free( &U );
switches	0:5c4d7b2438d3	974
switches	0:5c4d7b2438d3	975	return( ret );
switches	0:5c4d7b2438d3	976	}
switches	0:5c4d7b2438d3	977
switches	0:5c4d7b2438d3	978	/*
switches	0:5c4d7b2438d3	979	* Addition: R = P + Q, mixed affine-Jacobian coordinates (GECC 3.22)
switches	0:5c4d7b2438d3	980	*
switches	0:5c4d7b2438d3	981	* The coordinates of Q must be normalized (= affine),
switches	0:5c4d7b2438d3	982	* but those of P don't need to. R is not normalized.
switches	0:5c4d7b2438d3	983	*
switches	0:5c4d7b2438d3	984	* Special cases: (1) P or Q is zero, (2) R is zero, (3) P == Q.
switches	0:5c4d7b2438d3	985	* None of these cases can happen as intermediate step in ecp_mul_comb():
switches	0:5c4d7b2438d3	986	* - at each step, P, Q and R are multiples of the base point, the factor
switches	0:5c4d7b2438d3	987	* being less than its order, so none of them is zero;
switches	0:5c4d7b2438d3	988	* - Q is an odd multiple of the base point, P an even multiple,
switches	0:5c4d7b2438d3	989	* due to the choice of precomputed points in the modified comb method.
switches	0:5c4d7b2438d3	990	* So branches for these cases do not leak secret information.
switches	0:5c4d7b2438d3	991	*
switches	0:5c4d7b2438d3	992	* We accept Q->Z being unset (saving memory in tables) as meaning 1.
switches	0:5c4d7b2438d3	993	*
switches	0:5c4d7b2438d3	994	* Cost: 1A := 8M + 3S
switches	0:5c4d7b2438d3	995	*/
switches	0:5c4d7b2438d3	996	static int ecp_add_mixed( const mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	997	const mbedtls_ecp_point P, const mbedtls_ecp_point Q )
switches	0:5c4d7b2438d3	998	{
switches	0:5c4d7b2438d3	999	int ret;
switches	0:5c4d7b2438d3	1000	mbedtls_mpi T1, T2, T3, T4, X, Y, Z;
switches	0:5c4d7b2438d3	1001
switches	0:5c4d7b2438d3	1002	#if defined(MBEDTLS_SELF_TEST)
switches	0:5c4d7b2438d3	1003	add_count++;
switches	0:5c4d7b2438d3	1004	#endif
switches	0:5c4d7b2438d3	1005
switches	0:5c4d7b2438d3	1006	/*
switches	0:5c4d7b2438d3	1007	* Trivial cases: P == 0 or Q == 0 (case 1)
switches	0:5c4d7b2438d3	1008	*/
switches	0:5c4d7b2438d3	1009	if( mbedtls_mpi_cmp_int( &P->Z, 0 ) == 0 )
switches	0:5c4d7b2438d3	1010	return( mbedtls_ecp_copy( R, Q ) );
switches	0:5c4d7b2438d3	1011
switches	0:5c4d7b2438d3	1012	if( Q->Z.p != NULL && mbedtls_mpi_cmp_int( &Q->Z, 0 ) == 0 )
switches	0:5c4d7b2438d3	1013	return( mbedtls_ecp_copy( R, P ) );
switches	0:5c4d7b2438d3	1014
switches	0:5c4d7b2438d3	1015	/*
switches	0:5c4d7b2438d3	1016	* Make sure Q coordinates are normalized
switches	0:5c4d7b2438d3	1017	*/
switches	0:5c4d7b2438d3	1018	if( Q->Z.p != NULL && mbedtls_mpi_cmp_int( &Q->Z, 1 ) != 0 )
switches	0:5c4d7b2438d3	1019	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1020
switches	0:5c4d7b2438d3	1021	mbedtls_mpi_init( &T1 ); mbedtls_mpi_init( &T2 ); mbedtls_mpi_init( &T3 ); mbedtls_mpi_init( &T4 );
switches	0:5c4d7b2438d3	1022	mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z );
switches	0:5c4d7b2438d3	1023
switches	0:5c4d7b2438d3	1024	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &P->Z, &P->Z ) ); MOD_MUL( T1 );
switches	0:5c4d7b2438d3	1025	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T2, &T1, &P->Z ) ); MOD_MUL( T2 );
switches	0:5c4d7b2438d3	1026	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &T1, &Q->X ) ); MOD_MUL( T1 );
switches	0:5c4d7b2438d3	1027	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T2, &T2, &Q->Y ) ); MOD_MUL( T2 );
switches	0:5c4d7b2438d3	1028	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T1, &T1, &P->X ) ); MOD_SUB( T1 );
switches	0:5c4d7b2438d3	1029	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T2, &T2, &P->Y ) ); MOD_SUB( T2 );
switches	0:5c4d7b2438d3	1030
switches	0:5c4d7b2438d3	1031	/* Special cases (2) and (3) */
switches	0:5c4d7b2438d3	1032	if( mbedtls_mpi_cmp_int( &T1, 0 ) == 0 )
switches	0:5c4d7b2438d3	1033	{
switches	0:5c4d7b2438d3	1034	if( mbedtls_mpi_cmp_int( &T2, 0 ) == 0 )
switches	0:5c4d7b2438d3	1035	{
switches	0:5c4d7b2438d3	1036	ret = ecp_double_jac( grp, R, P );
switches	0:5c4d7b2438d3	1037	goto cleanup;
switches	0:5c4d7b2438d3	1038	}
switches	0:5c4d7b2438d3	1039	else
switches	0:5c4d7b2438d3	1040	{
switches	0:5c4d7b2438d3	1041	ret = mbedtls_ecp_set_zero( R );
switches	0:5c4d7b2438d3	1042	goto cleanup;
switches	0:5c4d7b2438d3	1043	}
switches	0:5c4d7b2438d3	1044	}
switches	0:5c4d7b2438d3	1045
switches	0:5c4d7b2438d3	1046	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &Z, &P->Z, &T1 ) ); MOD_MUL( Z );
switches	0:5c4d7b2438d3	1047	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T3, &T1, &T1 ) ); MOD_MUL( T3 );
switches	0:5c4d7b2438d3	1048	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T4, &T3, &T1 ) ); MOD_MUL( T4 );
switches	0:5c4d7b2438d3	1049	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T3, &T3, &P->X ) ); MOD_MUL( T3 );
switches	0:5c4d7b2438d3	1050	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &T1, &T3, 2 ) ); MOD_ADD( T1 );
switches	0:5c4d7b2438d3	1051	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &X, &T2, &T2 ) ); MOD_MUL( X );
switches	0:5c4d7b2438d3	1052	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &X, &X, &T1 ) ); MOD_SUB( X );
switches	0:5c4d7b2438d3	1053	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &X, &X, &T4 ) ); MOD_SUB( X );
switches	0:5c4d7b2438d3	1054	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T3, &T3, &X ) ); MOD_SUB( T3 );
switches	0:5c4d7b2438d3	1055	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T3, &T3, &T2 ) ); MOD_MUL( T3 );
switches	0:5c4d7b2438d3	1056	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T4, &T4, &P->Y ) ); MOD_MUL( T4 );
switches	0:5c4d7b2438d3	1057	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &Y, &T3, &T4 ) ); MOD_SUB( Y );
switches	0:5c4d7b2438d3	1058
switches	0:5c4d7b2438d3	1059	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->X, &X ) );
switches	0:5c4d7b2438d3	1060	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->Y, &Y ) );
switches	0:5c4d7b2438d3	1061	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R->Z, &Z ) );
switches	0:5c4d7b2438d3	1062
switches	0:5c4d7b2438d3	1063	cleanup:
switches	0:5c4d7b2438d3	1064
switches	0:5c4d7b2438d3	1065	mbedtls_mpi_free( &T1 ); mbedtls_mpi_free( &T2 ); mbedtls_mpi_free( &T3 ); mbedtls_mpi_free( &T4 );
switches	0:5c4d7b2438d3	1066	mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z );
switches	0:5c4d7b2438d3	1067
switches	0:5c4d7b2438d3	1068	return( ret );
switches	0:5c4d7b2438d3	1069	}
switches	0:5c4d7b2438d3	1070
switches	0:5c4d7b2438d3	1071	/*
switches	0:5c4d7b2438d3	1072	* Randomize jacobian coordinates:
switches	0:5c4d7b2438d3	1073	* (X, Y, Z) -> (l^2 X, l^3 Y, l Z) for random l
switches	0:5c4d7b2438d3	1074	* This is sort of the reverse operation of ecp_normalize_jac().
switches	0:5c4d7b2438d3	1075	*
switches	0:5c4d7b2438d3	1076	* This countermeasure was first suggested in [2].
switches	0:5c4d7b2438d3	1077	*/
switches	0:5c4d7b2438d3	1078	static int ecp_randomize_jac( const mbedtls_ecp_group grp, mbedtls_ecp_point pt,
switches	0:5c4d7b2438d3	1079	int (f_rng)(void , unsigned char , size_t), void p_rng )
switches	0:5c4d7b2438d3	1080	{
switches	0:5c4d7b2438d3	1081	int ret;
switches	0:5c4d7b2438d3	1082	mbedtls_mpi l, ll;
switches	0:5c4d7b2438d3	1083	size_t p_size = ( grp->pbits + 7 ) / 8;
switches	0:5c4d7b2438d3	1084	int count = 0;
switches	0:5c4d7b2438d3	1085
switches	0:5c4d7b2438d3	1086	mbedtls_mpi_init( &l ); mbedtls_mpi_init( &ll );
switches	0:5c4d7b2438d3	1087
switches	0:5c4d7b2438d3	1088	/* Generate l such that 1 < l < p */
switches	0:5c4d7b2438d3	1089	do
switches	0:5c4d7b2438d3	1090	{
switches	0:5c4d7b2438d3	1091	mbedtls_mpi_fill_random( &l, p_size, f_rng, p_rng );
switches	0:5c4d7b2438d3	1092
switches	0:5c4d7b2438d3	1093	while( mbedtls_mpi_cmp_mpi( &l, &grp->P ) >= 0 )
switches	0:5c4d7b2438d3	1094	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &l, 1 ) );
switches	0:5c4d7b2438d3	1095
switches	0:5c4d7b2438d3	1096	if( count++ > 10 )
switches	0:5c4d7b2438d3	1097	return( MBEDTLS_ERR_ECP_RANDOM_FAILED );
switches	0:5c4d7b2438d3	1098	}
switches	0:5c4d7b2438d3	1099	while( mbedtls_mpi_cmp_int( &l, 1 ) <= 0 );
switches	0:5c4d7b2438d3	1100
switches	0:5c4d7b2438d3	1101	/* Z = l * Z */
switches	0:5c4d7b2438d3	1102	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->Z, &pt->Z, &l ) ); MOD_MUL( pt->Z );
switches	0:5c4d7b2438d3	1103
switches	0:5c4d7b2438d3	1104	/* X = l^2 * X */
switches	0:5c4d7b2438d3	1105	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ll, &l, &l ) ); MOD_MUL( ll );
switches	0:5c4d7b2438d3	1106	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->X, &pt->X, &ll ) ); MOD_MUL( pt->X );
switches	0:5c4d7b2438d3	1107
switches	0:5c4d7b2438d3	1108	/* Y = l^3 * Y */
switches	0:5c4d7b2438d3	1109	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ll, &ll, &l ) ); MOD_MUL( ll );
switches	0:5c4d7b2438d3	1110	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &pt->Y, &pt->Y, &ll ) ); MOD_MUL( pt->Y );
switches	0:5c4d7b2438d3	1111
switches	0:5c4d7b2438d3	1112	cleanup:
switches	0:5c4d7b2438d3	1113	mbedtls_mpi_free( &l ); mbedtls_mpi_free( &ll );
switches	0:5c4d7b2438d3	1114
switches	0:5c4d7b2438d3	1115	return( ret );
switches	0:5c4d7b2438d3	1116	}
switches	0:5c4d7b2438d3	1117
switches	0:5c4d7b2438d3	1118	/*
switches	0:5c4d7b2438d3	1119	* Check and define parameters used by the comb method (see below for details)
switches	0:5c4d7b2438d3	1120	*/
switches	0:5c4d7b2438d3	1121	#if MBEDTLS_ECP_WINDOW_SIZE < 2 \|\| MBEDTLS_ECP_WINDOW_SIZE > 7
switches	0:5c4d7b2438d3	1122	#error "MBEDTLS_ECP_WINDOW_SIZE out of bounds"
switches	0:5c4d7b2438d3	1123	#endif
switches	0:5c4d7b2438d3	1124
switches	0:5c4d7b2438d3	1125	/* d = ceil( n / w ) */
switches	0:5c4d7b2438d3	1126	#define COMB_MAX_D ( MBEDTLS_ECP_MAX_BITS + 1 ) / 2
switches	0:5c4d7b2438d3	1127
switches	0:5c4d7b2438d3	1128	/* number of precomputed points */
switches	0:5c4d7b2438d3	1129	#define COMB_MAX_PRE ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) )
switches	0:5c4d7b2438d3	1130
switches	0:5c4d7b2438d3	1131	/*
switches	0:5c4d7b2438d3	1132	* Compute the representation of m that will be used with our comb method.
switches	0:5c4d7b2438d3	1133	*
switches	0:5c4d7b2438d3	1134	* The basic comb method is described in GECC 3.44 for example. We use a
switches	0:5c4d7b2438d3	1135	* modified version that provides resistance to SPA by avoiding zero
switches	0:5c4d7b2438d3	1136	* digits in the representation as in [3]. We modify the method further by
switches	0:5c4d7b2438d3	1137	* requiring that all K_i be odd, which has the small cost that our
switches	0:5c4d7b2438d3	1138	* representation uses one more K_i, due to carries.
switches	0:5c4d7b2438d3	1139	*
switches	0:5c4d7b2438d3	1140	* Also, for the sake of compactness, only the seven low-order bits of x[i]
switches	0:5c4d7b2438d3	1141	* are used to represent K_i, and the msb of x[i] encodes the the sign (s_i in
switches	0:5c4d7b2438d3	1142	* the paper): it is set if and only if if s_i == -1;
switches	0:5c4d7b2438d3	1143	*
switches	0:5c4d7b2438d3	1144	* Calling conventions:
switches	0:5c4d7b2438d3	1145	* - x is an array of size d + 1
switches	0:5c4d7b2438d3	1146	* - w is the size, ie number of teeth, of the comb, and must be between
switches	0:5c4d7b2438d3	1147	* 2 and 7 (in practice, between 2 and MBEDTLS_ECP_WINDOW_SIZE)
switches	0:5c4d7b2438d3	1148	* - m is the MPI, expected to be odd and such that bitlength(m) <= w * d
switches	0:5c4d7b2438d3	1149	* (the result will be incorrect if these assumptions are not satisfied)
switches	0:5c4d7b2438d3	1150	*/
switches	0:5c4d7b2438d3	1151	static void ecp_comb_fixed( unsigned char x[], size_t d,
switches	0:5c4d7b2438d3	1152	unsigned char w, const mbedtls_mpi *m )
switches	0:5c4d7b2438d3	1153	{
switches	0:5c4d7b2438d3	1154	size_t i, j;
switches	0:5c4d7b2438d3	1155	unsigned char c, cc, adjust;
switches	0:5c4d7b2438d3	1156
switches	0:5c4d7b2438d3	1157	memset( x, 0, d+1 );
switches	0:5c4d7b2438d3	1158
switches	0:5c4d7b2438d3	1159	/* First get the classical comb values (except for x_d = 0) */
switches	0:5c4d7b2438d3	1160	for( i = 0; i < d; i++ )
switches	0:5c4d7b2438d3	1161	for( j = 0; j < w; j++ )
switches	0:5c4d7b2438d3	1162	x[i] \|= mbedtls_mpi_get_bit( m, i + d * j ) << j;
switches	0:5c4d7b2438d3	1163
switches	0:5c4d7b2438d3	1164	/* Now make sure x_1 .. x_d are odd */
switches	0:5c4d7b2438d3	1165	c = 0;
switches	0:5c4d7b2438d3	1166	for( i = 1; i <= d; i++ )
switches	0:5c4d7b2438d3	1167	{
switches	0:5c4d7b2438d3	1168	/* Add carry and update it */
switches	0:5c4d7b2438d3	1169	cc = x[i] & c;
switches	0:5c4d7b2438d3	1170	x[i] = x[i] ^ c;
switches	0:5c4d7b2438d3	1171	c = cc;
switches	0:5c4d7b2438d3	1172
switches	0:5c4d7b2438d3	1173	/* Adjust if needed, avoiding branches */
switches	0:5c4d7b2438d3	1174	adjust = 1 - ( x[i] & 0x01 );
switches	0:5c4d7b2438d3	1175	c \|= x[i] & ( x[i-1] * adjust );
switches	0:5c4d7b2438d3	1176	x[i] = x[i] ^ ( x[i-1] * adjust );
switches	0:5c4d7b2438d3	1177	x[i-1] \|= adjust << 7;
switches	0:5c4d7b2438d3	1178	}
switches	0:5c4d7b2438d3	1179	}
switches	0:5c4d7b2438d3	1180
switches	0:5c4d7b2438d3	1181	/*
switches	0:5c4d7b2438d3	1182	* Precompute points for the comb method
switches	0:5c4d7b2438d3	1183	*
switches	0:5c4d7b2438d3	1184	* If i = i_{w-1} ... i_1 is the binary representation of i, then
switches	0:5c4d7b2438d3	1185	* T[i] = i_{w-1} 2^{(w-1)d} P + ... + i_1 2^d P + P
switches	0:5c4d7b2438d3	1186	*
switches	0:5c4d7b2438d3	1187	* T must be able to hold 2^{w - 1} elements
switches	0:5c4d7b2438d3	1188	*
switches	0:5c4d7b2438d3	1189	* Cost: d(w-1) D + (2^{w-1} - 1) A + 1 N(w-1) + 1 N(2^{w-1} - 1)
switches	0:5c4d7b2438d3	1190	*/
switches	0:5c4d7b2438d3	1191	static int ecp_precompute_comb( const mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	1192	mbedtls_ecp_point T[], const mbedtls_ecp_point *P,
switches	0:5c4d7b2438d3	1193	unsigned char w, size_t d )
switches	0:5c4d7b2438d3	1194	{
switches	0:5c4d7b2438d3	1195	int ret;
switches	0:5c4d7b2438d3	1196	unsigned char i, k;
switches	0:5c4d7b2438d3	1197	size_t j;
switches	0:5c4d7b2438d3	1198	mbedtls_ecp_point cur, TT[COMB_MAX_PRE - 1];
switches	0:5c4d7b2438d3	1199
switches	0:5c4d7b2438d3	1200	/*
switches	0:5c4d7b2438d3	1201	* Set T[0] = P and
switches	0:5c4d7b2438d3	1202	* T[2^{l-1}] = 2^{dl} P for l = 1 .. w-1 (this is not the final value)
switches	0:5c4d7b2438d3	1203	*/
switches	0:5c4d7b2438d3	1204	MBEDTLS_MPI_CHK( mbedtls_ecp_copy( &T[0], P ) );
switches	0:5c4d7b2438d3	1205
switches	0:5c4d7b2438d3	1206	k = 0;
switches	0:5c4d7b2438d3	1207	for( i = 1; i < ( 1U << ( w - 1 ) ); i <<= 1 )
switches	0:5c4d7b2438d3	1208	{
switches	0:5c4d7b2438d3	1209	cur = T + i;
switches	0:5c4d7b2438d3	1210	MBEDTLS_MPI_CHK( mbedtls_ecp_copy( cur, T + ( i >> 1 ) ) );
switches	0:5c4d7b2438d3	1211	for( j = 0; j < d; j++ )
switches	0:5c4d7b2438d3	1212	MBEDTLS_MPI_CHK( ecp_double_jac( grp, cur, cur ) );
switches	0:5c4d7b2438d3	1213
switches	0:5c4d7b2438d3	1214	TT[k++] = cur;
switches	0:5c4d7b2438d3	1215	}
switches	0:5c4d7b2438d3	1216
switches	0:5c4d7b2438d3	1217	MBEDTLS_MPI_CHK( ecp_normalize_jac_many( grp, TT, k ) );
switches	0:5c4d7b2438d3	1218
switches	0:5c4d7b2438d3	1219	/*
switches	0:5c4d7b2438d3	1220	* Compute the remaining ones using the minimal number of additions
switches	0:5c4d7b2438d3	1221	* Be careful to update T[2^l] only after using it!
switches	0:5c4d7b2438d3	1222	*/
switches	0:5c4d7b2438d3	1223	k = 0;
switches	0:5c4d7b2438d3	1224	for( i = 1; i < ( 1U << ( w - 1 ) ); i <<= 1 )
switches	0:5c4d7b2438d3	1225	{
switches	0:5c4d7b2438d3	1226	j = i;
switches	0:5c4d7b2438d3	1227	while( j-- )
switches	0:5c4d7b2438d3	1228	{
switches	0:5c4d7b2438d3	1229	MBEDTLS_MPI_CHK( ecp_add_mixed( grp, &T[i + j], &T[j], &T[i] ) );
switches	0:5c4d7b2438d3	1230	TT[k++] = &T[i + j];
switches	0:5c4d7b2438d3	1231	}
switches	0:5c4d7b2438d3	1232	}
switches	0:5c4d7b2438d3	1233
switches	0:5c4d7b2438d3	1234	MBEDTLS_MPI_CHK( ecp_normalize_jac_many( grp, TT, k ) );
switches	0:5c4d7b2438d3	1235
switches	0:5c4d7b2438d3	1236	cleanup:
switches	0:5c4d7b2438d3	1237	return( ret );
switches	0:5c4d7b2438d3	1238	}
switches	0:5c4d7b2438d3	1239
switches	0:5c4d7b2438d3	1240	/*
switches	0:5c4d7b2438d3	1241	* Select precomputed point: R = sign(i) * T[ abs(i) / 2 ]
switches	0:5c4d7b2438d3	1242	*/
switches	0:5c4d7b2438d3	1243	static int ecp_select_comb( const mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1244	const mbedtls_ecp_point T[], unsigned char t_len,
switches	0:5c4d7b2438d3	1245	unsigned char i )
switches	0:5c4d7b2438d3	1246	{
switches	0:5c4d7b2438d3	1247	int ret;
switches	0:5c4d7b2438d3	1248	unsigned char ii, j;
switches	0:5c4d7b2438d3	1249
switches	0:5c4d7b2438d3	1250	/* Ignore the "sign" bit and scale down */
switches	0:5c4d7b2438d3	1251	ii = ( i & 0x7Fu ) >> 1;
switches	0:5c4d7b2438d3	1252
switches	0:5c4d7b2438d3	1253	/* Read the whole table to thwart cache-based timing attacks */
switches	0:5c4d7b2438d3	1254	for( j = 0; j < t_len; j++ )
switches	0:5c4d7b2438d3	1255	{
switches	0:5c4d7b2438d3	1256	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_assign( &R->X, &T[j].X, j == ii ) );
switches	0:5c4d7b2438d3	1257	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_assign( &R->Y, &T[j].Y, j == ii ) );
switches	0:5c4d7b2438d3	1258	}
switches	0:5c4d7b2438d3	1259
switches	0:5c4d7b2438d3	1260	/* Safely invert result if i is "negative" */
switches	0:5c4d7b2438d3	1261	MBEDTLS_MPI_CHK( ecp_safe_invert_jac( grp, R, i >> 7 ) );
switches	0:5c4d7b2438d3	1262
switches	0:5c4d7b2438d3	1263	cleanup:
switches	0:5c4d7b2438d3	1264	return( ret );
switches	0:5c4d7b2438d3	1265	}
switches	0:5c4d7b2438d3	1266
switches	0:5c4d7b2438d3	1267	/*
switches	0:5c4d7b2438d3	1268	* Core multiplication algorithm for the (modified) comb method.
switches	0:5c4d7b2438d3	1269	* This part is actually common with the basic comb method (GECC 3.44)
switches	0:5c4d7b2438d3	1270	*
switches	0:5c4d7b2438d3	1271	* Cost: d A + d D + 1 R
switches	0:5c4d7b2438d3	1272	*/
switches	0:5c4d7b2438d3	1273	static int ecp_mul_comb_core( const mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1274	const mbedtls_ecp_point T[], unsigned char t_len,
switches	0:5c4d7b2438d3	1275	const unsigned char x[], size_t d,
switches	0:5c4d7b2438d3	1276	int (f_rng)(void , unsigned char *, size_t),
switches	0:5c4d7b2438d3	1277	void *p_rng )
switches	0:5c4d7b2438d3	1278	{
switches	0:5c4d7b2438d3	1279	int ret;
switches	0:5c4d7b2438d3	1280	mbedtls_ecp_point Txi;
switches	0:5c4d7b2438d3	1281	size_t i;
switches	0:5c4d7b2438d3	1282
switches	0:5c4d7b2438d3	1283	mbedtls_ecp_point_init( &Txi );
switches	0:5c4d7b2438d3	1284
switches	0:5c4d7b2438d3	1285	/* Start with a non-zero point and randomize its coordinates */
switches	0:5c4d7b2438d3	1286	i = d;
switches	0:5c4d7b2438d3	1287	MBEDTLS_MPI_CHK( ecp_select_comb( grp, R, T, t_len, x[i] ) );
switches	0:5c4d7b2438d3	1288	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &R->Z, 1 ) );
switches	0:5c4d7b2438d3	1289	if( f_rng != 0 )
switches	0:5c4d7b2438d3	1290	MBEDTLS_MPI_CHK( ecp_randomize_jac( grp, R, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1291
switches	0:5c4d7b2438d3	1292	while( i-- != 0 )
switches	0:5c4d7b2438d3	1293	{
switches	0:5c4d7b2438d3	1294	MBEDTLS_MPI_CHK( ecp_double_jac( grp, R, R ) );
switches	0:5c4d7b2438d3	1295	MBEDTLS_MPI_CHK( ecp_select_comb( grp, &Txi, T, t_len, x[i] ) );
switches	0:5c4d7b2438d3	1296	MBEDTLS_MPI_CHK( ecp_add_mixed( grp, R, R, &Txi ) );
switches	0:5c4d7b2438d3	1297	}
switches	0:5c4d7b2438d3	1298
switches	0:5c4d7b2438d3	1299	cleanup:
switches	0:5c4d7b2438d3	1300	mbedtls_ecp_point_free( &Txi );
switches	0:5c4d7b2438d3	1301
switches	0:5c4d7b2438d3	1302	return( ret );
switches	0:5c4d7b2438d3	1303	}
switches	0:5c4d7b2438d3	1304
switches	0:5c4d7b2438d3	1305	/*
switches	0:5c4d7b2438d3	1306	* Multiplication using the comb method,
switches	0:5c4d7b2438d3	1307	* for curves in short Weierstrass form
switches	0:5c4d7b2438d3	1308	*/
switches	0:5c4d7b2438d3	1309	static int ecp_mul_comb( mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1310	const mbedtls_mpi m, const mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	1311	int (f_rng)(void , unsigned char *, size_t),
switches	0:5c4d7b2438d3	1312	void *p_rng )
switches	0:5c4d7b2438d3	1313	{
switches	0:5c4d7b2438d3	1314	int ret;
switches	0:5c4d7b2438d3	1315	unsigned char w, m_is_odd, p_eq_g, pre_len, i;
switches	0:5c4d7b2438d3	1316	size_t d;
switches	0:5c4d7b2438d3	1317	unsigned char k[COMB_MAX_D + 1];
switches	0:5c4d7b2438d3	1318	mbedtls_ecp_point *T;
switches	0:5c4d7b2438d3	1319	mbedtls_mpi M, mm;
switches	0:5c4d7b2438d3	1320
switches	0:5c4d7b2438d3	1321	mbedtls_mpi_init( &M );
switches	0:5c4d7b2438d3	1322	mbedtls_mpi_init( &mm );
switches	0:5c4d7b2438d3	1323
switches	0:5c4d7b2438d3	1324	/* we need N to be odd to trnaform m in an odd number, check now */
switches	0:5c4d7b2438d3	1325	if( mbedtls_mpi_get_bit( &grp->N, 0 ) != 1 )
switches	0:5c4d7b2438d3	1326	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1327
switches	0:5c4d7b2438d3	1328	/*
switches	0:5c4d7b2438d3	1329	* Minimize the number of multiplications, that is minimize
switches	0:5c4d7b2438d3	1330	* 10 * d * w + 18 * 2^(w-1) + 11 * d + 7 * w, with d = ceil( nbits / w )
switches	0:5c4d7b2438d3	1331	* (see costs of the various parts, with 1S = 1M)
switches	0:5c4d7b2438d3	1332	*/
switches	0:5c4d7b2438d3	1333	w = grp->nbits >= 384 ? 5 : 4;
switches	0:5c4d7b2438d3	1334
switches	0:5c4d7b2438d3	1335	/*
switches	0:5c4d7b2438d3	1336	* If P == G, pre-compute a bit more, since this may be re-used later.
switches	0:5c4d7b2438d3	1337	* Just adding one avoids upping the cost of the first mul too much,
switches	0:5c4d7b2438d3	1338	* and the memory cost too.
switches	0:5c4d7b2438d3	1339	*/
switches	0:5c4d7b2438d3	1340	#if MBEDTLS_ECP_FIXED_POINT_OPTIM == 1
switches	0:5c4d7b2438d3	1341	p_eq_g = ( mbedtls_mpi_cmp_mpi( &P->Y, &grp->G.Y ) == 0 &&
switches	0:5c4d7b2438d3	1342	mbedtls_mpi_cmp_mpi( &P->X, &grp->G.X ) == 0 );
switches	0:5c4d7b2438d3	1343	if( p_eq_g )
switches	0:5c4d7b2438d3	1344	w++;
switches	0:5c4d7b2438d3	1345	#else
switches	0:5c4d7b2438d3	1346	p_eq_g = 0;
switches	0:5c4d7b2438d3	1347	#endif
switches	0:5c4d7b2438d3	1348
switches	0:5c4d7b2438d3	1349	/*
switches	0:5c4d7b2438d3	1350	* Make sure w is within bounds.
switches	0:5c4d7b2438d3	1351	* (The last test is useful only for very small curves in the test suite.)
switches	0:5c4d7b2438d3	1352	*/
switches	0:5c4d7b2438d3	1353	if( w > MBEDTLS_ECP_WINDOW_SIZE )
switches	0:5c4d7b2438d3	1354	w = MBEDTLS_ECP_WINDOW_SIZE;
switches	0:5c4d7b2438d3	1355	if( w >= grp->nbits )
switches	0:5c4d7b2438d3	1356	w = 2;
switches	0:5c4d7b2438d3	1357
switches	0:5c4d7b2438d3	1358	/* Other sizes that depend on w */
switches	0:5c4d7b2438d3	1359	pre_len = 1U << ( w - 1 );
switches	0:5c4d7b2438d3	1360	d = ( grp->nbits + w - 1 ) / w;
switches	0:5c4d7b2438d3	1361
switches	0:5c4d7b2438d3	1362	/*
switches	0:5c4d7b2438d3	1363	* Prepare precomputed points: if P == G we want to
switches	0:5c4d7b2438d3	1364	* use grp->T if already initialized, or initialize it.
switches	0:5c4d7b2438d3	1365	*/
switches	0:5c4d7b2438d3	1366	T = p_eq_g ? grp->T : NULL;
switches	0:5c4d7b2438d3	1367
switches	0:5c4d7b2438d3	1368	if( T == NULL )
switches	0:5c4d7b2438d3	1369	{
switches	0:5c4d7b2438d3	1370	T = mbedtls_calloc( pre_len, sizeof( mbedtls_ecp_point ) );
switches	0:5c4d7b2438d3	1371	if( T == NULL )
switches	0:5c4d7b2438d3	1372	{
switches	0:5c4d7b2438d3	1373	ret = MBEDTLS_ERR_ECP_ALLOC_FAILED;
switches	0:5c4d7b2438d3	1374	goto cleanup;
switches	0:5c4d7b2438d3	1375	}
switches	0:5c4d7b2438d3	1376
switches	0:5c4d7b2438d3	1377	MBEDTLS_MPI_CHK( ecp_precompute_comb( grp, T, P, w, d ) );
switches	0:5c4d7b2438d3	1378
switches	0:5c4d7b2438d3	1379	if( p_eq_g )
switches	0:5c4d7b2438d3	1380	{
switches	0:5c4d7b2438d3	1381	grp->T = T;
switches	0:5c4d7b2438d3	1382	grp->T_size = pre_len;
switches	0:5c4d7b2438d3	1383	}
switches	0:5c4d7b2438d3	1384	}
switches	0:5c4d7b2438d3	1385
switches	0:5c4d7b2438d3	1386	/*
switches	0:5c4d7b2438d3	1387	* Make sure M is odd (M = m or M = N - m, since N is odd)
switches	0:5c4d7b2438d3	1388	* using the fact that m * P = - (N - m) * P
switches	0:5c4d7b2438d3	1389	*/
switches	0:5c4d7b2438d3	1390	m_is_odd = ( mbedtls_mpi_get_bit( m, 0 ) == 1 );
switches	0:5c4d7b2438d3	1391	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &M, m ) );
switches	0:5c4d7b2438d3	1392	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &mm, &grp->N, m ) );
switches	0:5c4d7b2438d3	1393	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_assign( &M, &mm, ! m_is_odd ) );
switches	0:5c4d7b2438d3	1394
switches	0:5c4d7b2438d3	1395	/*
switches	0:5c4d7b2438d3	1396	* Go for comb multiplication, R = M * P
switches	0:5c4d7b2438d3	1397	*/
switches	0:5c4d7b2438d3	1398	ecp_comb_fixed( k, d, w, &M );
switches	0:5c4d7b2438d3	1399	MBEDTLS_MPI_CHK( ecp_mul_comb_core( grp, R, T, pre_len, k, d, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1400
switches	0:5c4d7b2438d3	1401	/*
switches	0:5c4d7b2438d3	1402	* Now get m * P from M * P and normalize it
switches	0:5c4d7b2438d3	1403	*/
switches	0:5c4d7b2438d3	1404	MBEDTLS_MPI_CHK( ecp_safe_invert_jac( grp, R, ! m_is_odd ) );
switches	0:5c4d7b2438d3	1405	MBEDTLS_MPI_CHK( ecp_normalize_jac( grp, R ) );
switches	0:5c4d7b2438d3	1406
switches	0:5c4d7b2438d3	1407	cleanup:
switches	0:5c4d7b2438d3	1408
switches	0:5c4d7b2438d3	1409	if( T != NULL && ! p_eq_g )
switches	0:5c4d7b2438d3	1410	{
switches	0:5c4d7b2438d3	1411	for( i = 0; i < pre_len; i++ )
switches	0:5c4d7b2438d3	1412	mbedtls_ecp_point_free( &T[i] );
switches	0:5c4d7b2438d3	1413	mbedtls_free( T );
switches	0:5c4d7b2438d3	1414	}
switches	0:5c4d7b2438d3	1415
switches	0:5c4d7b2438d3	1416	mbedtls_mpi_free( &M );
switches	0:5c4d7b2438d3	1417	mbedtls_mpi_free( &mm );
switches	0:5c4d7b2438d3	1418
switches	0:5c4d7b2438d3	1419	if( ret != 0 )
switches	0:5c4d7b2438d3	1420	mbedtls_ecp_point_free( R );
switches	0:5c4d7b2438d3	1421
switches	0:5c4d7b2438d3	1422	return( ret );
switches	0:5c4d7b2438d3	1423	}
switches	0:5c4d7b2438d3	1424
switches	0:5c4d7b2438d3	1425	#endif /* ECP_SHORTWEIERSTRASS */
switches	0:5c4d7b2438d3	1426
switches	0:5c4d7b2438d3	1427	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1428	/*
switches	0:5c4d7b2438d3	1429	* For Montgomery curves, we do all the internal arithmetic in projective
switches	0:5c4d7b2438d3	1430	* coordinates. Import/export of points uses only the x coordinates, which is
switches	0:5c4d7b2438d3	1431	* internaly represented as X / Z.
switches	0:5c4d7b2438d3	1432	*
switches	0:5c4d7b2438d3	1433	* For scalar multiplication, we'll use a Montgomery ladder.
switches	0:5c4d7b2438d3	1434	*/
switches	0:5c4d7b2438d3	1435
switches	0:5c4d7b2438d3	1436	/*
switches	0:5c4d7b2438d3	1437	* Normalize Montgomery x/z coordinates: X = X/Z, Z = 1
switches	0:5c4d7b2438d3	1438	* Cost: 1M + 1I
switches	0:5c4d7b2438d3	1439	*/
switches	0:5c4d7b2438d3	1440	static int ecp_normalize_mxz( const mbedtls_ecp_group grp, mbedtls_ecp_point P )
switches	0:5c4d7b2438d3	1441	{
switches	0:5c4d7b2438d3	1442	int ret;
switches	0:5c4d7b2438d3	1443
switches	0:5c4d7b2438d3	1444	MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &P->Z, &P->Z, &grp->P ) );
switches	0:5c4d7b2438d3	1445	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &P->X, &P->X, &P->Z ) ); MOD_MUL( P->X );
switches	0:5c4d7b2438d3	1446	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &P->Z, 1 ) );
switches	0:5c4d7b2438d3	1447
switches	0:5c4d7b2438d3	1448	cleanup:
switches	0:5c4d7b2438d3	1449	return( ret );
switches	0:5c4d7b2438d3	1450	}
switches	0:5c4d7b2438d3	1451
switches	0:5c4d7b2438d3	1452	/*
switches	0:5c4d7b2438d3	1453	* Randomize projective x/z coordinates:
switches	0:5c4d7b2438d3	1454	* (X, Z) -> (l X, l Z) for random l
switches	0:5c4d7b2438d3	1455	* This is sort of the reverse operation of ecp_normalize_mxz().
switches	0:5c4d7b2438d3	1456	*
switches	0:5c4d7b2438d3	1457	* This countermeasure was first suggested in [2].
switches	0:5c4d7b2438d3	1458	* Cost: 2M
switches	0:5c4d7b2438d3	1459	*/
switches	0:5c4d7b2438d3	1460	static int ecp_randomize_mxz( const mbedtls_ecp_group grp, mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	1461	int (f_rng)(void , unsigned char , size_t), void p_rng )
switches	0:5c4d7b2438d3	1462	{
switches	0:5c4d7b2438d3	1463	int ret;
switches	0:5c4d7b2438d3	1464	mbedtls_mpi l;
switches	0:5c4d7b2438d3	1465	size_t p_size = ( grp->pbits + 7 ) / 8;
switches	0:5c4d7b2438d3	1466	int count = 0;
switches	0:5c4d7b2438d3	1467
switches	0:5c4d7b2438d3	1468	mbedtls_mpi_init( &l );
switches	0:5c4d7b2438d3	1469
switches	0:5c4d7b2438d3	1470	/* Generate l such that 1 < l < p */
switches	0:5c4d7b2438d3	1471	do
switches	0:5c4d7b2438d3	1472	{
switches	0:5c4d7b2438d3	1473	mbedtls_mpi_fill_random( &l, p_size, f_rng, p_rng );
switches	0:5c4d7b2438d3	1474
switches	0:5c4d7b2438d3	1475	while( mbedtls_mpi_cmp_mpi( &l, &grp->P ) >= 0 )
switches	0:5c4d7b2438d3	1476	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &l, 1 ) );
switches	0:5c4d7b2438d3	1477
switches	0:5c4d7b2438d3	1478	if( count++ > 10 )
switches	0:5c4d7b2438d3	1479	return( MBEDTLS_ERR_ECP_RANDOM_FAILED );
switches	0:5c4d7b2438d3	1480	}
switches	0:5c4d7b2438d3	1481	while( mbedtls_mpi_cmp_int( &l, 1 ) <= 0 );
switches	0:5c4d7b2438d3	1482
switches	0:5c4d7b2438d3	1483	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &P->X, &P->X, &l ) ); MOD_MUL( P->X );
switches	0:5c4d7b2438d3	1484	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &P->Z, &P->Z, &l ) ); MOD_MUL( P->Z );
switches	0:5c4d7b2438d3	1485
switches	0:5c4d7b2438d3	1486	cleanup:
switches	0:5c4d7b2438d3	1487	mbedtls_mpi_free( &l );
switches	0:5c4d7b2438d3	1488
switches	0:5c4d7b2438d3	1489	return( ret );
switches	0:5c4d7b2438d3	1490	}
switches	0:5c4d7b2438d3	1491
switches	0:5c4d7b2438d3	1492	/*
switches	0:5c4d7b2438d3	1493	* Double-and-add: R = 2P, S = P + Q, with d = X(P - Q),
switches	0:5c4d7b2438d3	1494	* for Montgomery curves in x/z coordinates.
switches	0:5c4d7b2438d3	1495	*
switches	0:5c4d7b2438d3	1496	* http://www.hyperelliptic.org/EFD/g1p/auto-code/montgom/xz/ladder/mladd-1987-m.op3
switches	0:5c4d7b2438d3	1497	* with
switches	0:5c4d7b2438d3	1498	* d = X1
switches	0:5c4d7b2438d3	1499	* P = (X2, Z2)
switches	0:5c4d7b2438d3	1500	* Q = (X3, Z3)
switches	0:5c4d7b2438d3	1501	* R = (X4, Z4)
switches	0:5c4d7b2438d3	1502	* S = (X5, Z5)
switches	0:5c4d7b2438d3	1503	* and eliminating temporary variables tO, ..., t4.
switches	0:5c4d7b2438d3	1504	*
switches	0:5c4d7b2438d3	1505	* Cost: 5M + 4S
switches	0:5c4d7b2438d3	1506	*/
switches	0:5c4d7b2438d3	1507	static int ecp_double_add_mxz( const mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	1508	mbedtls_ecp_point R, mbedtls_ecp_point S,
switches	0:5c4d7b2438d3	1509	const mbedtls_ecp_point P, const mbedtls_ecp_point Q,
switches	0:5c4d7b2438d3	1510	const mbedtls_mpi *d )
switches	0:5c4d7b2438d3	1511	{
switches	0:5c4d7b2438d3	1512	int ret;
switches	0:5c4d7b2438d3	1513	mbedtls_mpi A, AA, B, BB, E, C, D, DA, CB;
switches	0:5c4d7b2438d3	1514
switches	0:5c4d7b2438d3	1515	mbedtls_mpi_init( &A ); mbedtls_mpi_init( &AA ); mbedtls_mpi_init( &B );
switches	0:5c4d7b2438d3	1516	mbedtls_mpi_init( &BB ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &C );
switches	0:5c4d7b2438d3	1517	mbedtls_mpi_init( &D ); mbedtls_mpi_init( &DA ); mbedtls_mpi_init( &CB );
switches	0:5c4d7b2438d3	1518
switches	0:5c4d7b2438d3	1519	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &A, &P->X, &P->Z ) ); MOD_ADD( A );
switches	0:5c4d7b2438d3	1520	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &AA, &A, &A ) ); MOD_MUL( AA );
switches	0:5c4d7b2438d3	1521	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &B, &P->X, &P->Z ) ); MOD_SUB( B );
switches	0:5c4d7b2438d3	1522	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &BB, &B, &B ) ); MOD_MUL( BB );
switches	0:5c4d7b2438d3	1523	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &E, &AA, &BB ) ); MOD_SUB( E );
switches	0:5c4d7b2438d3	1524	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &C, &Q->X, &Q->Z ) ); MOD_ADD( C );
switches	0:5c4d7b2438d3	1525	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &D, &Q->X, &Q->Z ) ); MOD_SUB( D );
switches	0:5c4d7b2438d3	1526	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DA, &D, &A ) ); MOD_MUL( DA );
switches	0:5c4d7b2438d3	1527	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &CB, &C, &B ) ); MOD_MUL( CB );
switches	0:5c4d7b2438d3	1528	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &S->X, &DA, &CB ) ); MOD_MUL( S->X );
switches	0:5c4d7b2438d3	1529	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S->X, &S->X, &S->X ) ); MOD_MUL( S->X );
switches	0:5c4d7b2438d3	1530	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &S->Z, &DA, &CB ) ); MOD_SUB( S->Z );
switches	0:5c4d7b2438d3	1531	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S->Z, &S->Z, &S->Z ) ); MOD_MUL( S->Z );
switches	0:5c4d7b2438d3	1532	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &S->Z, d, &S->Z ) ); MOD_MUL( S->Z );
switches	0:5c4d7b2438d3	1533	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &R->X, &AA, &BB ) ); MOD_MUL( R->X );
switches	0:5c4d7b2438d3	1534	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &R->Z, &grp->A, &E ) ); MOD_MUL( R->Z );
switches	0:5c4d7b2438d3	1535	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &R->Z, &BB, &R->Z ) ); MOD_ADD( R->Z );
switches	0:5c4d7b2438d3	1536	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &R->Z, &E, &R->Z ) ); MOD_MUL( R->Z );
switches	0:5c4d7b2438d3	1537
switches	0:5c4d7b2438d3	1538	cleanup:
switches	0:5c4d7b2438d3	1539	mbedtls_mpi_free( &A ); mbedtls_mpi_free( &AA ); mbedtls_mpi_free( &B );
switches	0:5c4d7b2438d3	1540	mbedtls_mpi_free( &BB ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &C );
switches	0:5c4d7b2438d3	1541	mbedtls_mpi_free( &D ); mbedtls_mpi_free( &DA ); mbedtls_mpi_free( &CB );
switches	0:5c4d7b2438d3	1542
switches	0:5c4d7b2438d3	1543	return( ret );
switches	0:5c4d7b2438d3	1544	}
switches	0:5c4d7b2438d3	1545
switches	0:5c4d7b2438d3	1546	/*
switches	0:5c4d7b2438d3	1547	* Multiplication with Montgomery ladder in x/z coordinates,
switches	0:5c4d7b2438d3	1548	* for curves in Montgomery form
switches	0:5c4d7b2438d3	1549	*/
switches	0:5c4d7b2438d3	1550	static int ecp_mul_mxz( mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1551	const mbedtls_mpi m, const mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	1552	int (f_rng)(void , unsigned char *, size_t),
switches	0:5c4d7b2438d3	1553	void *p_rng )
switches	0:5c4d7b2438d3	1554	{
switches	0:5c4d7b2438d3	1555	int ret;
switches	0:5c4d7b2438d3	1556	size_t i;
switches	0:5c4d7b2438d3	1557	unsigned char b;
switches	0:5c4d7b2438d3	1558	mbedtls_ecp_point RP;
switches	0:5c4d7b2438d3	1559	mbedtls_mpi PX;
switches	0:5c4d7b2438d3	1560
switches	0:5c4d7b2438d3	1561	mbedtls_ecp_point_init( &RP ); mbedtls_mpi_init( &PX );
switches	0:5c4d7b2438d3	1562
switches	0:5c4d7b2438d3	1563	/* Save PX and read from P before writing to R, in case P == R */
switches	0:5c4d7b2438d3	1564	MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &PX, &P->X ) );
switches	0:5c4d7b2438d3	1565	MBEDTLS_MPI_CHK( mbedtls_ecp_copy( &RP, P ) );
switches	0:5c4d7b2438d3	1566
switches	0:5c4d7b2438d3	1567	/* Set R to zero in modified x/z coordinates */
switches	0:5c4d7b2438d3	1568	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &R->X, 1 ) );
switches	0:5c4d7b2438d3	1569	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &R->Z, 0 ) );
switches	0:5c4d7b2438d3	1570	mbedtls_mpi_free( &R->Y );
switches	0:5c4d7b2438d3	1571
switches	0:5c4d7b2438d3	1572	/* RP.X might be sligtly larger than P, so reduce it */
switches	0:5c4d7b2438d3	1573	MOD_ADD( RP.X );
switches	0:5c4d7b2438d3	1574
switches	0:5c4d7b2438d3	1575	/* Randomize coordinates of the starting point */
switches	0:5c4d7b2438d3	1576	if( f_rng != NULL )
switches	0:5c4d7b2438d3	1577	MBEDTLS_MPI_CHK( ecp_randomize_mxz( grp, &RP, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1578
switches	0:5c4d7b2438d3	1579	/* Loop invariant: R = result so far, RP = R + P */
switches	0:5c4d7b2438d3	1580	i = mbedtls_mpi_bitlen( m ); /* one past the (zero-based) most significant bit */
switches	0:5c4d7b2438d3	1581	while( i-- > 0 )
switches	0:5c4d7b2438d3	1582	{
switches	0:5c4d7b2438d3	1583	b = mbedtls_mpi_get_bit( m, i );
switches	0:5c4d7b2438d3	1584	/*
switches	0:5c4d7b2438d3	1585	* if (b) R = 2R + P else R = 2R,
switches	0:5c4d7b2438d3	1586	* which is:
switches	0:5c4d7b2438d3	1587	* if (b) double_add( RP, R, RP, R )
switches	0:5c4d7b2438d3	1588	* else double_add( R, RP, R, RP )
switches	0:5c4d7b2438d3	1589	* but using safe conditional swaps to avoid leaks
switches	0:5c4d7b2438d3	1590	*/
switches	0:5c4d7b2438d3	1591	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_swap( &R->X, &RP.X, b ) );
switches	0:5c4d7b2438d3	1592	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_swap( &R->Z, &RP.Z, b ) );
switches	0:5c4d7b2438d3	1593	MBEDTLS_MPI_CHK( ecp_double_add_mxz( grp, R, &RP, R, &RP, &PX ) );
switches	0:5c4d7b2438d3	1594	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_swap( &R->X, &RP.X, b ) );
switches	0:5c4d7b2438d3	1595	MBEDTLS_MPI_CHK( mbedtls_mpi_safe_cond_swap( &R->Z, &RP.Z, b ) );
switches	0:5c4d7b2438d3	1596	}
switches	0:5c4d7b2438d3	1597
switches	0:5c4d7b2438d3	1598	MBEDTLS_MPI_CHK( ecp_normalize_mxz( grp, R ) );
switches	0:5c4d7b2438d3	1599
switches	0:5c4d7b2438d3	1600	cleanup:
switches	0:5c4d7b2438d3	1601	mbedtls_ecp_point_free( &RP ); mbedtls_mpi_free( &PX );
switches	0:5c4d7b2438d3	1602
switches	0:5c4d7b2438d3	1603	return( ret );
switches	0:5c4d7b2438d3	1604	}
switches	0:5c4d7b2438d3	1605
switches	0:5c4d7b2438d3	1606	#endif /* ECP_MONTGOMERY */
switches	0:5c4d7b2438d3	1607
switches	0:5c4d7b2438d3	1608	/*
switches	0:5c4d7b2438d3	1609	* Multiplication R = m * P
switches	0:5c4d7b2438d3	1610	*/
switches	0:5c4d7b2438d3	1611	int mbedtls_ecp_mul( mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1612	const mbedtls_mpi m, const mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	1613	int (f_rng)(void , unsigned char , size_t), void p_rng )
switches	0:5c4d7b2438d3	1614	{
switches	0:5c4d7b2438d3	1615	int ret;
switches	0:5c4d7b2438d3	1616
switches	0:5c4d7b2438d3	1617	/* Common sanity checks */
switches	0:5c4d7b2438d3	1618	if( mbedtls_mpi_cmp_int( &P->Z, 1 ) != 0 )
switches	0:5c4d7b2438d3	1619	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1620
switches	0:5c4d7b2438d3	1621	if( ( ret = mbedtls_ecp_check_privkey( grp, m ) ) != 0 \|\|
switches	0:5c4d7b2438d3	1622	( ret = mbedtls_ecp_check_pubkey( grp, P ) ) != 0 )
switches	0:5c4d7b2438d3	1623	return( ret );
switches	0:5c4d7b2438d3	1624
switches	0:5c4d7b2438d3	1625	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1626	if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
switches	0:5c4d7b2438d3	1627	return( ecp_mul_mxz( grp, R, m, P, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1628	#endif
switches	0:5c4d7b2438d3	1629	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	1630	if( ecp_get_type( grp ) == ECP_TYPE_SHORT_WEIERSTRASS )
switches	0:5c4d7b2438d3	1631	return( ecp_mul_comb( grp, R, m, P, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1632	#endif
switches	0:5c4d7b2438d3	1633	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1634	}
switches	0:5c4d7b2438d3	1635
switches	0:5c4d7b2438d3	1636	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	1637	/*
switches	0:5c4d7b2438d3	1638	* Check that an affine point is valid as a public key,
switches	0:5c4d7b2438d3	1639	* short weierstrass curves (SEC1 3.2.3.1)
switches	0:5c4d7b2438d3	1640	*/
switches	0:5c4d7b2438d3	1641	static int ecp_check_pubkey_sw( const mbedtls_ecp_group grp, const mbedtls_ecp_point pt )
switches	0:5c4d7b2438d3	1642	{
switches	0:5c4d7b2438d3	1643	int ret;
switches	0:5c4d7b2438d3	1644	mbedtls_mpi YY, RHS;
switches	0:5c4d7b2438d3	1645
switches	0:5c4d7b2438d3	1646	/* pt coordinates must be normalized for our checks */
switches	0:5c4d7b2438d3	1647	if( mbedtls_mpi_cmp_int( &pt->X, 0 ) < 0 \|\|
switches	0:5c4d7b2438d3	1648	mbedtls_mpi_cmp_int( &pt->Y, 0 ) < 0 \|\|
switches	0:5c4d7b2438d3	1649	mbedtls_mpi_cmp_mpi( &pt->X, &grp->P ) >= 0 \|\|
switches	0:5c4d7b2438d3	1650	mbedtls_mpi_cmp_mpi( &pt->Y, &grp->P ) >= 0 )
switches	0:5c4d7b2438d3	1651	return( MBEDTLS_ERR_ECP_INVALID_KEY );
switches	0:5c4d7b2438d3	1652
switches	0:5c4d7b2438d3	1653	mbedtls_mpi_init( &YY ); mbedtls_mpi_init( &RHS );
switches	0:5c4d7b2438d3	1654
switches	0:5c4d7b2438d3	1655	/*
switches	0:5c4d7b2438d3	1656	* YY = Y^2
switches	0:5c4d7b2438d3	1657	* RHS = X (X^2 + A) + B = X^3 + A X + B
switches	0:5c4d7b2438d3	1658	*/
switches	0:5c4d7b2438d3	1659	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &YY, &pt->Y, &pt->Y ) ); MOD_MUL( YY );
switches	0:5c4d7b2438d3	1660	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &RHS, &pt->X, &pt->X ) ); MOD_MUL( RHS );
switches	0:5c4d7b2438d3	1661
switches	0:5c4d7b2438d3	1662	/* Special case for A = -3 */
switches	0:5c4d7b2438d3	1663	if( grp->A.p == NULL )
switches	0:5c4d7b2438d3	1664	{
switches	0:5c4d7b2438d3	1665	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &RHS, &RHS, 3 ) ); MOD_SUB( RHS );
switches	0:5c4d7b2438d3	1666	}
switches	0:5c4d7b2438d3	1667	else
switches	0:5c4d7b2438d3	1668	{
switches	0:5c4d7b2438d3	1669	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &RHS, &RHS, &grp->A ) ); MOD_ADD( RHS );
switches	0:5c4d7b2438d3	1670	}
switches	0:5c4d7b2438d3	1671
switches	0:5c4d7b2438d3	1672	MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &RHS, &RHS, &pt->X ) ); MOD_MUL( RHS );
switches	0:5c4d7b2438d3	1673	MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &RHS, &RHS, &grp->B ) ); MOD_ADD( RHS );
switches	0:5c4d7b2438d3	1674
switches	0:5c4d7b2438d3	1675	if( mbedtls_mpi_cmp_mpi( &YY, &RHS ) != 0 )
switches	0:5c4d7b2438d3	1676	ret = MBEDTLS_ERR_ECP_INVALID_KEY;
switches	0:5c4d7b2438d3	1677
switches	0:5c4d7b2438d3	1678	cleanup:
switches	0:5c4d7b2438d3	1679
switches	0:5c4d7b2438d3	1680	mbedtls_mpi_free( &YY ); mbedtls_mpi_free( &RHS );
switches	0:5c4d7b2438d3	1681
switches	0:5c4d7b2438d3	1682	return( ret );
switches	0:5c4d7b2438d3	1683	}
switches	0:5c4d7b2438d3	1684	#endif /* ECP_SHORTWEIERSTRASS */
switches	0:5c4d7b2438d3	1685
switches	0:5c4d7b2438d3	1686	/*
switches	0:5c4d7b2438d3	1687	* R = m * P with shortcuts for m == 1 and m == -1
switches	0:5c4d7b2438d3	1688	* NOT constant-time - ONLY for short Weierstrass!
switches	0:5c4d7b2438d3	1689	*/
switches	0:5c4d7b2438d3	1690	static int mbedtls_ecp_mul_shortcuts( mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	1691	mbedtls_ecp_point *R,
switches	0:5c4d7b2438d3	1692	const mbedtls_mpi *m,
switches	0:5c4d7b2438d3	1693	const mbedtls_ecp_point *P )
switches	0:5c4d7b2438d3	1694	{
switches	0:5c4d7b2438d3	1695	int ret;
switches	0:5c4d7b2438d3	1696
switches	0:5c4d7b2438d3	1697	if( mbedtls_mpi_cmp_int( m, 1 ) == 0 )
switches	0:5c4d7b2438d3	1698	{
switches	0:5c4d7b2438d3	1699	MBEDTLS_MPI_CHK( mbedtls_ecp_copy( R, P ) );
switches	0:5c4d7b2438d3	1700	}
switches	0:5c4d7b2438d3	1701	else if( mbedtls_mpi_cmp_int( m, -1 ) == 0 )
switches	0:5c4d7b2438d3	1702	{
switches	0:5c4d7b2438d3	1703	MBEDTLS_MPI_CHK( mbedtls_ecp_copy( R, P ) );
switches	0:5c4d7b2438d3	1704	if( mbedtls_mpi_cmp_int( &R->Y, 0 ) != 0 )
switches	0:5c4d7b2438d3	1705	MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &R->Y, &grp->P, &R->Y ) );
switches	0:5c4d7b2438d3	1706	}
switches	0:5c4d7b2438d3	1707	else
switches	0:5c4d7b2438d3	1708	{
switches	0:5c4d7b2438d3	1709	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, R, m, P, NULL, NULL ) );
switches	0:5c4d7b2438d3	1710	}
switches	0:5c4d7b2438d3	1711
switches	0:5c4d7b2438d3	1712	cleanup:
switches	0:5c4d7b2438d3	1713	return( ret );
switches	0:5c4d7b2438d3	1714	}
switches	0:5c4d7b2438d3	1715
switches	0:5c4d7b2438d3	1716	/*
switches	0:5c4d7b2438d3	1717	* Linear combination
switches	0:5c4d7b2438d3	1718	* NOT constant-time
switches	0:5c4d7b2438d3	1719	*/
switches	0:5c4d7b2438d3	1720	int mbedtls_ecp_muladd( mbedtls_ecp_group grp, mbedtls_ecp_point R,
switches	0:5c4d7b2438d3	1721	const mbedtls_mpi m, const mbedtls_ecp_point P,
switches	0:5c4d7b2438d3	1722	const mbedtls_mpi n, const mbedtls_ecp_point Q )
switches	0:5c4d7b2438d3	1723	{
switches	0:5c4d7b2438d3	1724	int ret;
switches	0:5c4d7b2438d3	1725	mbedtls_ecp_point mP;
switches	0:5c4d7b2438d3	1726
switches	0:5c4d7b2438d3	1727	if( ecp_get_type( grp ) != ECP_TYPE_SHORT_WEIERSTRASS )
switches	0:5c4d7b2438d3	1728	return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
switches	0:5c4d7b2438d3	1729
switches	0:5c4d7b2438d3	1730	mbedtls_ecp_point_init( &mP );
switches	0:5c4d7b2438d3	1731
switches	0:5c4d7b2438d3	1732	MBEDTLS_MPI_CHK( mbedtls_ecp_mul_shortcuts( grp, &mP, m, P ) );
switches	0:5c4d7b2438d3	1733	MBEDTLS_MPI_CHK( mbedtls_ecp_mul_shortcuts( grp, R, n, Q ) );
switches	0:5c4d7b2438d3	1734
switches	0:5c4d7b2438d3	1735	MBEDTLS_MPI_CHK( ecp_add_mixed( grp, R, &mP, R ) );
switches	0:5c4d7b2438d3	1736	MBEDTLS_MPI_CHK( ecp_normalize_jac( grp, R ) );
switches	0:5c4d7b2438d3	1737
switches	0:5c4d7b2438d3	1738	cleanup:
switches	0:5c4d7b2438d3	1739	mbedtls_ecp_point_free( &mP );
switches	0:5c4d7b2438d3	1740
switches	0:5c4d7b2438d3	1741	return( ret );
switches	0:5c4d7b2438d3	1742	}
switches	0:5c4d7b2438d3	1743
switches	0:5c4d7b2438d3	1744
switches	0:5c4d7b2438d3	1745	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1746	/*
switches	0:5c4d7b2438d3	1747	* Check validity of a public key for Montgomery curves with x-only schemes
switches	0:5c4d7b2438d3	1748	*/
switches	0:5c4d7b2438d3	1749	static int ecp_check_pubkey_mx( const mbedtls_ecp_group grp, const mbedtls_ecp_point pt )
switches	0:5c4d7b2438d3	1750	{
switches	0:5c4d7b2438d3	1751	/* [Curve25519 p. 5] Just check X is the correct number of bytes */
switches	0:5c4d7b2438d3	1752	if( mbedtls_mpi_size( &pt->X ) > ( grp->nbits + 7 ) / 8 )
switches	0:5c4d7b2438d3	1753	return( MBEDTLS_ERR_ECP_INVALID_KEY );
switches	0:5c4d7b2438d3	1754
switches	0:5c4d7b2438d3	1755	return( 0 );
switches	0:5c4d7b2438d3	1756	}
switches	0:5c4d7b2438d3	1757	#endif /* ECP_MONTGOMERY */
switches	0:5c4d7b2438d3	1758
switches	0:5c4d7b2438d3	1759	/*
switches	0:5c4d7b2438d3	1760	* Check that a point is valid as a public key
switches	0:5c4d7b2438d3	1761	*/
switches	0:5c4d7b2438d3	1762	int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group grp, const mbedtls_ecp_point pt )
switches	0:5c4d7b2438d3	1763	{
switches	0:5c4d7b2438d3	1764	/* Must use affine coordinates */
switches	0:5c4d7b2438d3	1765	if( mbedtls_mpi_cmp_int( &pt->Z, 1 ) != 0 )
switches	0:5c4d7b2438d3	1766	return( MBEDTLS_ERR_ECP_INVALID_KEY );
switches	0:5c4d7b2438d3	1767
switches	0:5c4d7b2438d3	1768	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1769	if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
switches	0:5c4d7b2438d3	1770	return( ecp_check_pubkey_mx( grp, pt ) );
switches	0:5c4d7b2438d3	1771	#endif
switches	0:5c4d7b2438d3	1772	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	1773	if( ecp_get_type( grp ) == ECP_TYPE_SHORT_WEIERSTRASS )
switches	0:5c4d7b2438d3	1774	return( ecp_check_pubkey_sw( grp, pt ) );
switches	0:5c4d7b2438d3	1775	#endif
switches	0:5c4d7b2438d3	1776	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1777	}
switches	0:5c4d7b2438d3	1778
switches	0:5c4d7b2438d3	1779	/*
switches	0:5c4d7b2438d3	1780	* Check that an mbedtls_mpi is valid as a private key
switches	0:5c4d7b2438d3	1781	*/
switches	0:5c4d7b2438d3	1782	int mbedtls_ecp_check_privkey( const mbedtls_ecp_group grp, const mbedtls_mpi d )
switches	0:5c4d7b2438d3	1783	{
switches	0:5c4d7b2438d3	1784	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1785	if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
switches	0:5c4d7b2438d3	1786	{
switches	0:5c4d7b2438d3	1787	/* see [Curve25519] page 5 */
switches	0:5c4d7b2438d3	1788	if( mbedtls_mpi_get_bit( d, 0 ) != 0 \|\|
switches	0:5c4d7b2438d3	1789	mbedtls_mpi_get_bit( d, 1 ) != 0 \|\|
switches	0:5c4d7b2438d3	1790	mbedtls_mpi_get_bit( d, 2 ) != 0 \|\|
switches	0:5c4d7b2438d3	1791	mbedtls_mpi_bitlen( d ) - 1 != grp->nbits ) /* mbedtls_mpi_bitlen is one-based! */
switches	0:5c4d7b2438d3	1792	return( MBEDTLS_ERR_ECP_INVALID_KEY );
switches	0:5c4d7b2438d3	1793	else
switches	0:5c4d7b2438d3	1794	return( 0 );
switches	0:5c4d7b2438d3	1795	}
switches	0:5c4d7b2438d3	1796	#endif /* ECP_MONTGOMERY */
switches	0:5c4d7b2438d3	1797	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	1798	if( ecp_get_type( grp ) == ECP_TYPE_SHORT_WEIERSTRASS )
switches	0:5c4d7b2438d3	1799	{
switches	0:5c4d7b2438d3	1800	/* see SEC1 3.2 */
switches	0:5c4d7b2438d3	1801	if( mbedtls_mpi_cmp_int( d, 1 ) < 0 \|\|
switches	0:5c4d7b2438d3	1802	mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 )
switches	0:5c4d7b2438d3	1803	return( MBEDTLS_ERR_ECP_INVALID_KEY );
switches	0:5c4d7b2438d3	1804	else
switches	0:5c4d7b2438d3	1805	return( 0 );
switches	0:5c4d7b2438d3	1806	}
switches	0:5c4d7b2438d3	1807	#endif /* ECP_SHORTWEIERSTRASS */
switches	0:5c4d7b2438d3	1808
switches	0:5c4d7b2438d3	1809	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1810	}
switches	0:5c4d7b2438d3	1811
switches	0:5c4d7b2438d3	1812	/*
switches	0:5c4d7b2438d3	1813	* Generate a keypair with configurable base point
switches	0:5c4d7b2438d3	1814	*/
switches	0:5c4d7b2438d3	1815	int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	1816	const mbedtls_ecp_point *G,
switches	0:5c4d7b2438d3	1817	mbedtls_mpi d, mbedtls_ecp_point Q,
switches	0:5c4d7b2438d3	1818	int (f_rng)(void , unsigned char *, size_t),
switches	0:5c4d7b2438d3	1819	void *p_rng )
switches	0:5c4d7b2438d3	1820	{
switches	0:5c4d7b2438d3	1821	int ret;
switches	0:5c4d7b2438d3	1822	size_t n_size = ( grp->nbits + 7 ) / 8;
switches	0:5c4d7b2438d3	1823
switches	0:5c4d7b2438d3	1824	#if defined(ECP_MONTGOMERY)
switches	0:5c4d7b2438d3	1825	if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
switches	0:5c4d7b2438d3	1826	{
switches	0:5c4d7b2438d3	1827	/* [M225] page 5 */
switches	0:5c4d7b2438d3	1828	size_t b;
switches	0:5c4d7b2438d3	1829
switches	0:5c4d7b2438d3	1830	do {
switches	0:5c4d7b2438d3	1831	MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( d, n_size, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1832	} while( mbedtls_mpi_bitlen( d ) == 0);
switches	0:5c4d7b2438d3	1833
switches	0:5c4d7b2438d3	1834	/* Make sure the most significant bit is nbits */
switches	0:5c4d7b2438d3	1835	b = mbedtls_mpi_bitlen( d ) - 1; /* mbedtls_mpi_bitlen is one-based */
switches	0:5c4d7b2438d3	1836	if( b > grp->nbits )
switches	0:5c4d7b2438d3	1837	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( d, b - grp->nbits ) );
switches	0:5c4d7b2438d3	1838	else
switches	0:5c4d7b2438d3	1839	MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, grp->nbits, 1 ) );
switches	0:5c4d7b2438d3	1840
switches	0:5c4d7b2438d3	1841	/* Make sure the last three bits are unset */
switches	0:5c4d7b2438d3	1842	MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, 0, 0 ) );
switches	0:5c4d7b2438d3	1843	MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, 1, 0 ) );
switches	0:5c4d7b2438d3	1844	MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, 2, 0 ) );
switches	0:5c4d7b2438d3	1845	}
switches	0:5c4d7b2438d3	1846	else
switches	0:5c4d7b2438d3	1847	#endif /* ECP_MONTGOMERY */
switches	0:5c4d7b2438d3	1848	#if defined(ECP_SHORTWEIERSTRASS)
switches	0:5c4d7b2438d3	1849	if( ecp_get_type( grp ) == ECP_TYPE_SHORT_WEIERSTRASS )
switches	0:5c4d7b2438d3	1850	{
switches	0:5c4d7b2438d3	1851	/* SEC1 3.2.1: Generate d such that 1 <= n < N */
switches	0:5c4d7b2438d3	1852	int count = 0;
switches	0:5c4d7b2438d3	1853	unsigned char rnd[MBEDTLS_ECP_MAX_BYTES];
switches	0:5c4d7b2438d3	1854
switches	0:5c4d7b2438d3	1855	/*
switches	0:5c4d7b2438d3	1856	* Match the procedure given in RFC 6979 (deterministic ECDSA):
switches	0:5c4d7b2438d3	1857	* - use the same byte ordering;
switches	0:5c4d7b2438d3	1858	* - keep the leftmost nbits bits of the generated octet string;
switches	0:5c4d7b2438d3	1859	* - try until result is in the desired range.
switches	0:5c4d7b2438d3	1860	* This also avoids any biais, which is especially important for ECDSA.
switches	0:5c4d7b2438d3	1861	*/
switches	0:5c4d7b2438d3	1862	do
switches	0:5c4d7b2438d3	1863	{
switches	0:5c4d7b2438d3	1864	MBEDTLS_MPI_CHK( f_rng( p_rng, rnd, n_size ) );
switches	0:5c4d7b2438d3	1865	MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( d, rnd, n_size ) );
switches	0:5c4d7b2438d3	1866	MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( d, 8 * n_size - grp->nbits ) );
switches	0:5c4d7b2438d3	1867
switches	0:5c4d7b2438d3	1868	/*
switches	0:5c4d7b2438d3	1869	* Each try has at worst a probability 1/2 of failing (the msb has
switches	0:5c4d7b2438d3	1870	* a probability 1/2 of being 0, and then the result will be < N),
switches	0:5c4d7b2438d3	1871	* so after 30 tries failure probability is a most 2**(-30).
switches	0:5c4d7b2438d3	1872	*
switches	0:5c4d7b2438d3	1873	* For most curves, 1 try is enough with overwhelming probability,
switches	0:5c4d7b2438d3	1874	* since N starts with a lot of 1s in binary, but some curves
switches	0:5c4d7b2438d3	1875	* such as secp224k1 are actually very close to the worst case.
switches	0:5c4d7b2438d3	1876	*/
switches	0:5c4d7b2438d3	1877	if( ++count > 30 )
switches	0:5c4d7b2438d3	1878	return( MBEDTLS_ERR_ECP_RANDOM_FAILED );
switches	0:5c4d7b2438d3	1879	}
switches	0:5c4d7b2438d3	1880	while( mbedtls_mpi_cmp_int( d, 1 ) < 0 \|\|
switches	0:5c4d7b2438d3	1881	mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 );
switches	0:5c4d7b2438d3	1882	}
switches	0:5c4d7b2438d3	1883	else
switches	0:5c4d7b2438d3	1884	#endif /* ECP_SHORTWEIERSTRASS */
switches	0:5c4d7b2438d3	1885	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1886
switches	0:5c4d7b2438d3	1887	cleanup:
switches	0:5c4d7b2438d3	1888	if( ret != 0 )
switches	0:5c4d7b2438d3	1889	return( ret );
switches	0:5c4d7b2438d3	1890
switches	0:5c4d7b2438d3	1891	return( mbedtls_ecp_mul( grp, Q, d, G, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1892	}
switches	0:5c4d7b2438d3	1893
switches	0:5c4d7b2438d3	1894	/*
switches	0:5c4d7b2438d3	1895	* Generate key pair, wrapper for conventional base point
switches	0:5c4d7b2438d3	1896	*/
switches	0:5c4d7b2438d3	1897	int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp,
switches	0:5c4d7b2438d3	1898	mbedtls_mpi d, mbedtls_ecp_point Q,
switches	0:5c4d7b2438d3	1899	int (f_rng)(void , unsigned char *, size_t),
switches	0:5c4d7b2438d3	1900	void *p_rng )
switches	0:5c4d7b2438d3	1901	{
switches	0:5c4d7b2438d3	1902	return( mbedtls_ecp_gen_keypair_base( grp, &grp->G, d, Q, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1903	}
switches	0:5c4d7b2438d3	1904
switches	0:5c4d7b2438d3	1905	/*
switches	0:5c4d7b2438d3	1906	* Generate a keypair, prettier wrapper
switches	0:5c4d7b2438d3	1907	*/
switches	0:5c4d7b2438d3	1908	int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
switches	0:5c4d7b2438d3	1909	int (f_rng)(void , unsigned char , size_t), void p_rng )
switches	0:5c4d7b2438d3	1910	{
switches	0:5c4d7b2438d3	1911	int ret;
switches	0:5c4d7b2438d3	1912
switches	0:5c4d7b2438d3	1913	if( ( ret = mbedtls_ecp_group_load( &key->grp, grp_id ) ) != 0 )
switches	0:5c4d7b2438d3	1914	return( ret );
switches	0:5c4d7b2438d3	1915
switches	0:5c4d7b2438d3	1916	return( mbedtls_ecp_gen_keypair( &key->grp, &key->d, &key->Q, f_rng, p_rng ) );
switches	0:5c4d7b2438d3	1917	}
switches	0:5c4d7b2438d3	1918
switches	0:5c4d7b2438d3	1919	/*
switches	0:5c4d7b2438d3	1920	* Check a public-private key pair
switches	0:5c4d7b2438d3	1921	*/
switches	0:5c4d7b2438d3	1922	int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair pub, const mbedtls_ecp_keypair prv )
switches	0:5c4d7b2438d3	1923	{
switches	0:5c4d7b2438d3	1924	int ret;
switches	0:5c4d7b2438d3	1925	mbedtls_ecp_point Q;
switches	0:5c4d7b2438d3	1926	mbedtls_ecp_group grp;
switches	0:5c4d7b2438d3	1927
switches	0:5c4d7b2438d3	1928	if( pub->grp.id == MBEDTLS_ECP_DP_NONE \|\|
switches	0:5c4d7b2438d3	1929	pub->grp.id != prv->grp.id \|\|
switches	0:5c4d7b2438d3	1930	mbedtls_mpi_cmp_mpi( &pub->Q.X, &prv->Q.X ) \|\|
switches	0:5c4d7b2438d3	1931	mbedtls_mpi_cmp_mpi( &pub->Q.Y, &prv->Q.Y ) \|\|
switches	0:5c4d7b2438d3	1932	mbedtls_mpi_cmp_mpi( &pub->Q.Z, &prv->Q.Z ) )
switches	0:5c4d7b2438d3	1933	{
switches	0:5c4d7b2438d3	1934	return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
switches	0:5c4d7b2438d3	1935	}
switches	0:5c4d7b2438d3	1936
switches	0:5c4d7b2438d3	1937	mbedtls_ecp_point_init( &Q );
switches	0:5c4d7b2438d3	1938	mbedtls_ecp_group_init( &grp );
switches	0:5c4d7b2438d3	1939
switches	0:5c4d7b2438d3	1940	/* mbedtls_ecp_mul() needs a non-const group... */
switches	0:5c4d7b2438d3	1941	mbedtls_ecp_group_copy( &grp, &prv->grp );
switches	0:5c4d7b2438d3	1942
switches	0:5c4d7b2438d3	1943	/* Also checks d is valid */
switches	0:5c4d7b2438d3	1944	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &Q, &prv->d, &prv->grp.G, NULL, NULL ) );
switches	0:5c4d7b2438d3	1945
switches	0:5c4d7b2438d3	1946	if( mbedtls_mpi_cmp_mpi( &Q.X, &prv->Q.X ) \|\|
switches	0:5c4d7b2438d3	1947	mbedtls_mpi_cmp_mpi( &Q.Y, &prv->Q.Y ) \|\|
switches	0:5c4d7b2438d3	1948	mbedtls_mpi_cmp_mpi( &Q.Z, &prv->Q.Z ) )
switches	0:5c4d7b2438d3	1949	{
switches	0:5c4d7b2438d3	1950	ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
switches	0:5c4d7b2438d3	1951	goto cleanup;
switches	0:5c4d7b2438d3	1952	}
switches	0:5c4d7b2438d3	1953
switches	0:5c4d7b2438d3	1954	cleanup:
switches	0:5c4d7b2438d3	1955	mbedtls_ecp_point_free( &Q );
switches	0:5c4d7b2438d3	1956	mbedtls_ecp_group_free( &grp );
switches	0:5c4d7b2438d3	1957
switches	0:5c4d7b2438d3	1958	return( ret );
switches	0:5c4d7b2438d3	1959	}
switches	0:5c4d7b2438d3	1960
switches	0:5c4d7b2438d3	1961	#if defined(MBEDTLS_SELF_TEST)
switches	0:5c4d7b2438d3	1962
switches	0:5c4d7b2438d3	1963	/*
switches	0:5c4d7b2438d3	1964	* Checkup routine
switches	0:5c4d7b2438d3	1965	*/
switches	0:5c4d7b2438d3	1966	int mbedtls_ecp_self_test( int verbose )
switches	0:5c4d7b2438d3	1967	{
switches	0:5c4d7b2438d3	1968	int ret;
switches	0:5c4d7b2438d3	1969	size_t i;
switches	0:5c4d7b2438d3	1970	mbedtls_ecp_group grp;
switches	0:5c4d7b2438d3	1971	mbedtls_ecp_point R, P;
switches	0:5c4d7b2438d3	1972	mbedtls_mpi m;
switches	0:5c4d7b2438d3	1973	unsigned long add_c_prev, dbl_c_prev, mul_c_prev;
switches	0:5c4d7b2438d3	1974	/* exponents especially adapted for secp192r1 */
switches	0:5c4d7b2438d3	1975	const char *exponents[] =
switches	0:5c4d7b2438d3	1976	{
switches	0:5c4d7b2438d3	1977	"000000000000000000000000000000000000000000000001", /* one */
switches	0:5c4d7b2438d3	1978	"FFFFFFFFFFFFFFFFFFFFFFFF99DEF836146BC9B1B4D22830", /* N - 1 */
switches	0:5c4d7b2438d3	1979	"5EA6F389A38B8BC81E767753B15AA5569E1782E30ABE7D25", /* random */
switches	0:5c4d7b2438d3	1980	"400000000000000000000000000000000000000000000000", /* one and zeros */
switches	0:5c4d7b2438d3	1981	"7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF", /* all ones */
switches	0:5c4d7b2438d3	1982	"555555555555555555555555555555555555555555555555", /* 101010... */
switches	0:5c4d7b2438d3	1983	};
switches	0:5c4d7b2438d3	1984
switches	0:5c4d7b2438d3	1985	mbedtls_ecp_group_init( &grp );
switches	0:5c4d7b2438d3	1986	mbedtls_ecp_point_init( &R );
switches	0:5c4d7b2438d3	1987	mbedtls_ecp_point_init( &P );
switches	0:5c4d7b2438d3	1988	mbedtls_mpi_init( &m );
switches	0:5c4d7b2438d3	1989
switches	0:5c4d7b2438d3	1990	/* Use secp192r1 if available, or any available curve */
switches	0:5c4d7b2438d3	1991	#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
switches	0:5c4d7b2438d3	1992	MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &grp, MBEDTLS_ECP_DP_SECP192R1 ) );
switches	0:5c4d7b2438d3	1993	#else
switches	0:5c4d7b2438d3	1994	MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &grp, mbedtls_ecp_curve_list()->grp_id ) );
switches	0:5c4d7b2438d3	1995	#endif
switches	0:5c4d7b2438d3	1996
switches	0:5c4d7b2438d3	1997	if( verbose != 0 )
switches	0:5c4d7b2438d3	1998	mbedtls_printf( " ECP test #1 (constant op_count, base point G): " );
switches	0:5c4d7b2438d3	1999
switches	0:5c4d7b2438d3	2000	/* Do a dummy multiplication first to trigger precomputation */
switches	0:5c4d7b2438d3	2001	MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &m, 2 ) );
switches	0:5c4d7b2438d3	2002	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &P, &m, &grp.G, NULL, NULL ) );
switches	0:5c4d7b2438d3	2003
switches	0:5c4d7b2438d3	2004	add_count = 0;
switches	0:5c4d7b2438d3	2005	dbl_count = 0;
switches	0:5c4d7b2438d3	2006	mul_count = 0;
switches	0:5c4d7b2438d3	2007	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &m, 16, exponents[0] ) );
switches	0:5c4d7b2438d3	2008	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &R, &m, &grp.G, NULL, NULL ) );
switches	0:5c4d7b2438d3	2009
switches	0:5c4d7b2438d3	2010	for( i = 1; i < sizeof( exponents ) / sizeof( exponents[0] ); i++ )
switches	0:5c4d7b2438d3	2011	{
switches	0:5c4d7b2438d3	2012	add_c_prev = add_count;
switches	0:5c4d7b2438d3	2013	dbl_c_prev = dbl_count;
switches	0:5c4d7b2438d3	2014	mul_c_prev = mul_count;
switches	0:5c4d7b2438d3	2015	add_count = 0;
switches	0:5c4d7b2438d3	2016	dbl_count = 0;
switches	0:5c4d7b2438d3	2017	mul_count = 0;
switches	0:5c4d7b2438d3	2018
switches	0:5c4d7b2438d3	2019	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &m, 16, exponents[i] ) );
switches	0:5c4d7b2438d3	2020	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &R, &m, &grp.G, NULL, NULL ) );
switches	0:5c4d7b2438d3	2021
switches	0:5c4d7b2438d3	2022	if( add_count != add_c_prev \|\|
switches	0:5c4d7b2438d3	2023	dbl_count != dbl_c_prev \|\|
switches	0:5c4d7b2438d3	2024	mul_count != mul_c_prev )
switches	0:5c4d7b2438d3	2025	{
switches	0:5c4d7b2438d3	2026	if( verbose != 0 )
switches	0:5c4d7b2438d3	2027	mbedtls_printf( "failed (%u)\n", (unsigned int) i );
switches	0:5c4d7b2438d3	2028
switches	0:5c4d7b2438d3	2029	ret = 1;
switches	0:5c4d7b2438d3	2030	goto cleanup;
switches	0:5c4d7b2438d3	2031	}
switches	0:5c4d7b2438d3	2032	}
switches	0:5c4d7b2438d3	2033
switches	0:5c4d7b2438d3	2034	if( verbose != 0 )
switches	0:5c4d7b2438d3	2035	mbedtls_printf( "passed\n" );
switches	0:5c4d7b2438d3	2036
switches	0:5c4d7b2438d3	2037	if( verbose != 0 )
switches	0:5c4d7b2438d3	2038	mbedtls_printf( " ECP test #2 (constant op_count, other point): " );
switches	0:5c4d7b2438d3	2039	/* We computed P = 2G last time, use it */
switches	0:5c4d7b2438d3	2040
switches	0:5c4d7b2438d3	2041	add_count = 0;
switches	0:5c4d7b2438d3	2042	dbl_count = 0;
switches	0:5c4d7b2438d3	2043	mul_count = 0;
switches	0:5c4d7b2438d3	2044	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &m, 16, exponents[0] ) );
switches	0:5c4d7b2438d3	2045	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &R, &m, &P, NULL, NULL ) );
switches	0:5c4d7b2438d3	2046
switches	0:5c4d7b2438d3	2047	for( i = 1; i < sizeof( exponents ) / sizeof( exponents[0] ); i++ )
switches	0:5c4d7b2438d3	2048	{
switches	0:5c4d7b2438d3	2049	add_c_prev = add_count;
switches	0:5c4d7b2438d3	2050	dbl_c_prev = dbl_count;
switches	0:5c4d7b2438d3	2051	mul_c_prev = mul_count;
switches	0:5c4d7b2438d3	2052	add_count = 0;
switches	0:5c4d7b2438d3	2053	dbl_count = 0;
switches	0:5c4d7b2438d3	2054	mul_count = 0;
switches	0:5c4d7b2438d3	2055
switches	0:5c4d7b2438d3	2056	MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &m, 16, exponents[i] ) );
switches	0:5c4d7b2438d3	2057	MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &R, &m, &P, NULL, NULL ) );
switches	0:5c4d7b2438d3	2058
switches	0:5c4d7b2438d3	2059	if( add_count != add_c_prev \|\|
switches	0:5c4d7b2438d3	2060	dbl_count != dbl_c_prev \|\|
switches	0:5c4d7b2438d3	2061	mul_count != mul_c_prev )
switches	0:5c4d7b2438d3	2062	{
switches	0:5c4d7b2438d3	2063	if( verbose != 0 )
switches	0:5c4d7b2438d3	2064	mbedtls_printf( "failed (%u)\n", (unsigned int) i );
switches	0:5c4d7b2438d3	2065
switches	0:5c4d7b2438d3	2066	ret = 1;
switches	0:5c4d7b2438d3	2067	goto cleanup;
switches	0:5c4d7b2438d3	2068	}
switches	0:5c4d7b2438d3	2069	}
switches	0:5c4d7b2438d3	2070
switches	0:5c4d7b2438d3	2071	if( verbose != 0 )
switches	0:5c4d7b2438d3	2072	mbedtls_printf( "passed\n" );
switches	0:5c4d7b2438d3	2073
switches	0:5c4d7b2438d3	2074	cleanup:
switches	0:5c4d7b2438d3	2075
switches	0:5c4d7b2438d3	2076	if( ret < 0 && verbose != 0 )
switches	0:5c4d7b2438d3	2077	mbedtls_printf( "Unexpected error, return code = %08X\n", ret );
switches	0:5c4d7b2438d3	2078
switches	0:5c4d7b2438d3	2079	mbedtls_ecp_group_free( &grp );
switches	0:5c4d7b2438d3	2080	mbedtls_ecp_point_free( &R );
switches	0:5c4d7b2438d3	2081	mbedtls_ecp_point_free( &P );
switches	0:5c4d7b2438d3	2082	mbedtls_mpi_free( &m );
switches	0:5c4d7b2438d3	2083
switches	0:5c4d7b2438d3	2084	if( verbose != 0 )
switches	0:5c4d7b2438d3	2085	mbedtls_printf( "\n" );
switches	0:5c4d7b2438d3	2086
switches	0:5c4d7b2438d3	2087	return( ret );
switches	0:5c4d7b2438d3	2088	}
switches	0:5c4d7b2438d3	2089
switches	0:5c4d7b2438d3	2090	#endif /* MBEDTLS_SELF_TEST */
switches	0:5c4d7b2438d3	2091
switches	0:5c4d7b2438d3	2092	#endif /* MBEDTLS_ECP_C */

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Type:	Library
Created:	11 Nov 2016
Imports:	21
Forks:	0
Commits:	4
Dependents:	1
Dependencies:	0
Followers:	4

This repository is Public (Unlisted).

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Greg Steiert

Jesse Marroquin

features/mbedtls/src/ecp.c@3:1198227e6421, 2016-12-16 (annotated)

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