WebSVN – Kolibri OS – Blame – /programs/develop/libraries/kos_mbedtls/library/havege.c

Rev	Author	Line No.	Line
8774	rgimad	1	/**
		2	* \brief HAVEGE: HArdware Volatile Entropy Gathering and Expansion
		3	*
		4	* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
		5	* SPDX-License-Identifier: GPL-2.0
		6	*
		7	* This program is free software; you can redistribute it and/or modify
		8	* it under the terms of the GNU General Public License as published by
		9	* the Free Software Foundation; either version 2 of the License, or
		10	* (at your option) any later version.
		11	*
		12	* This program is distributed in the hope that it will be useful,
		13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		15	* GNU General Public License for more details.
		16	*
		17	* You should have received a copy of the GNU General Public License along
		18	* with this program; if not, write to the Free Software Foundation, Inc.,
		19	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
		20	*
		21	* This file is part of mbed TLS (https://tls.mbed.org)
		22	*/
		23	/*
		24	* The HAVEGE RNG was designed by Andre Seznec in 2002.
		25	*
		26	* http://www.irisa.fr/caps/projects/hipsor/publi.php
		27	*
		28	* Contact: seznec(at)irisa_dot_fr - orocheco(at)irisa_dot_fr
		29	*/
		30
		31	#if !defined(MBEDTLS_CONFIG_FILE)
		32	#include "mbedtls/config.h"
		33	#else
		34	#include MBEDTLS_CONFIG_FILE
		35	#endif
		36
		37	#if defined(MBEDTLS_HAVEGE_C)
		38
		39	#include "mbedtls/havege.h"
		40	#include "mbedtls/timing.h"
		41	#include "mbedtls/platform_util.h"
		42
		43	#include
		44	#include
		45
		46	/* If int isn't capable of storing 2^32 distinct values, the code of this
		47	* module may cause a processor trap or a miscalculation. If int is more
		48	* than 32 bits, the code may not calculate the intended values. */
		49	#if INT_MIN + 1 != -0x7fffffff
		50	#error "The HAVEGE module requires int to be exactly 32 bits, with INT_MIN = -2^31."
		51	#endif
		52	#if UINT_MAX != 0xffffffff
		53	#error "The HAVEGE module requires unsigned to be exactly 32 bits."
		54	#endif
		55
		56	/* ------------------------------------------------------------------------
		57	* On average, one iteration accesses two 8-word blocks in the havege WALK
		58	* table, and generates 16 words in the RES array.
		59	*
		60	* The data read in the WALK table is updated and permuted after each use.
		61	* The result of the hardware clock counter read is used for this update.
		62	*
		63	* 25 conditional tests are present. The conditional tests are grouped in
		64	* two nested groups of 12 conditional tests and 1 test that controls the
		65	* permutation; on average, there should be 6 tests executed and 3 of them
		66	* should be mispredicted.
		67	* ------------------------------------------------------------------------
		68	*/
		69
		70	#define SWAP(X,Y) { unsigned *T = (X); (X) = (Y); (Y) = T; }
		71
		72	#define TST1_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1;
		73	#define TST2_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1;
		74
		75	#define TST1_LEAVE U1++; }
		76	#define TST2_LEAVE U2++; }
		77
		78	#define ONE_ITERATION \
		79	\
		80	PTEST = PT1 >> 20; \
		81	\
		82	TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \
		83	TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \
		84	TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \
		85	\
		86	TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \
		87	TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \
		88	TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \
		89	\
		90	PTX = (PT1 >> 18) & 7; \
		91	PT1 &= 0x1FFF; \
		92	PT2 &= 0x1FFF; \
		93	CLK = (unsigned) mbedtls_timing_hardclock(); \
		94	\
		95	i = 0; \
		96	A = &WALK[PT1 ]; RES[i++] ^= *A; \
		97	B = &WALK[PT2 ]; RES[i++] ^= *B; \
		98	C = &WALK[PT1 ^ 1]; RES[i++] ^= *C; \
		99	D = &WALK[PT2 ^ 4]; RES[i++] ^= *D; \
		100	\
		101	IN = (A >> (1)) ^ (A << (31)) ^ CLK; \
		102	A = (B >> (2)) ^ (*B << (30)) ^ CLK; \
		103	*B = IN ^ U1; \
		104	C = (C >> (3)) ^ (*C << (29)) ^ CLK; \
		105	D = (D >> (4)) ^ (*D << (28)) ^ CLK; \
		106	\
		107	A = &WALK[PT1 ^ 2]; RES[i++] ^= *A; \
		108	B = &WALK[PT2 ^ 2]; RES[i++] ^= *B; \
		109	C = &WALK[PT1 ^ 3]; RES[i++] ^= *C; \
		110	D = &WALK[PT2 ^ 6]; RES[i++] ^= *D; \
		111	\
		112	if( PTEST & 1 ) SWAP( A, C ); \
		113	\
		114	IN = (A >> (5)) ^ (A << (27)) ^ CLK; \
		115	A = (B >> (6)) ^ (*B << (26)) ^ CLK; \
		116	*B = IN; CLK = (unsigned) mbedtls_timing_hardclock(); \
		117	C = (C >> (7)) ^ (*C << (25)) ^ CLK; \
		118	D = (D >> (8)) ^ (*D << (24)) ^ CLK; \
		119	\
		120	A = &WALK[PT1 ^ 4]; \
		121	B = &WALK[PT2 ^ 1]; \
		122	\
		123	PTEST = PT2 >> 1; \
		124	\
		125	PT2 = (RES[(i - 8) ^ PTY] ^ WALK[PT2 ^ PTY ^ 7]); \
		126	PT2 = ((PT2 & 0x1FFF) & (~8)) ^ ((PT1 ^ 8) & 0x8); \
		127	PTY = (PT2 >> 10) & 7; \
		128	\
		129	TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \
		130	TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \
		131	TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \
		132	\
		133	TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \
		134	TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \
		135	TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \
		136	\
		137	C = &WALK[PT1 ^ 5]; \
		138	D = &WALK[PT2 ^ 5]; \
		139	\
		140	RES[i++] ^= *A; \
		141	RES[i++] ^= *B; \
		142	RES[i++] ^= *C; \
		143	RES[i++] ^= *D; \
		144	\
		145	IN = (A >> ( 9)) ^ (A << (23)) ^ CLK; \
		146	A = (B >> (10)) ^ (*B << (22)) ^ CLK; \
		147	*B = IN ^ U2; \
		148	C = (C >> (11)) ^ (*C << (21)) ^ CLK; \
		149	D = (D >> (12)) ^ (*D << (20)) ^ CLK; \
		150	\
		151	A = &WALK[PT1 ^ 6]; RES[i++] ^= *A; \
		152	B = &WALK[PT2 ^ 3]; RES[i++] ^= *B; \
		153	C = &WALK[PT1 ^ 7]; RES[i++] ^= *C; \
		154	D = &WALK[PT2 ^ 7]; RES[i++] ^= *D; \
		155	\
		156	IN = (A >> (13)) ^ (A << (19)) ^ CLK; \
		157	A = (B >> (14)) ^ (*B << (18)) ^ CLK; \
		158	*B = IN; \
		159	C = (C >> (15)) ^ (*C << (17)) ^ CLK; \
		160	D = (D >> (16)) ^ (*D << (16)) ^ CLK; \
		161	\
		162	PT1 = ( RES[( i - 8 ) ^ PTX] ^ \
		163	WALK[PT1 ^ PTX ^ 7] ) & (~1); \
		164	PT1 ^= (PT2 ^ 0x10) & 0x10; \
		165	\
		166	for( n++, i = 0; i < 16; i++ ) \
		167	POOL[n % MBEDTLS_HAVEGE_COLLECT_SIZE] ^= RES[i];
		168
		169	/*
		170	* Entropy gathering function
		171	*/
		172	static void havege_fill( mbedtls_havege_state *hs )
		173	{
		174	unsigned i, n = 0;
		175	unsigned U1, U2, A, B, C, D;
		176	unsigned PT1, PT2, WALK, POOL, RES[16];
		177	unsigned PTX, PTY, CLK, PTEST, IN;
		178
		179	WALK = (unsigned *) hs->WALK;
		180	POOL = (unsigned *) hs->pool;
		181	PT1 = hs->PT1;
		182	PT2 = hs->PT2;
		183
		184	PTX = U1 = 0;
		185	PTY = U2 = 0;
		186
		187	(void)PTX;
		188
		189	memset( RES, 0, sizeof( RES ) );
		190
		191	while( n < MBEDTLS_HAVEGE_COLLECT_SIZE * 4 )
		192	{
		193	ONE_ITERATION
		194	ONE_ITERATION
		195	ONE_ITERATION
		196	ONE_ITERATION
		197	}
		198
		199	hs->PT1 = PT1;
		200	hs->PT2 = PT2;
		201
		202	hs->offset[0] = 0;
		203	hs->offset[1] = MBEDTLS_HAVEGE_COLLECT_SIZE / 2;
		204	}
		205
		206	/*
		207	* HAVEGE initialization
		208	*/
		209	void mbedtls_havege_init( mbedtls_havege_state *hs )
		210	{
		211	memset( hs, 0, sizeof( mbedtls_havege_state ) );
		212
		213	havege_fill( hs );
		214	}
		215
		216	void mbedtls_havege_free( mbedtls_havege_state *hs )
		217	{
		218	if( hs == NULL )
		219	return;
		220
		221	mbedtls_platform_zeroize( hs, sizeof( mbedtls_havege_state ) );
		222	}
		223
		224	/*
		225	* HAVEGE rand function
		226	*/
		227	int mbedtls_havege_random( void p_rng, unsigned char buf, size_t len )
		228	{
		229	int val;
		230	size_t use_len;
		231	mbedtls_havege_state hs = (mbedtls_havege_state ) p_rng;
		232	unsigned char *p = buf;
		233
		234	while( len > 0 )
		235	{
		236	use_len = len;
		237	if( use_len > sizeof(int) )
		238	use_len = sizeof(int);
		239
		240	if( hs->offset[1] >= MBEDTLS_HAVEGE_COLLECT_SIZE )
		241	havege_fill( hs );
		242
		243	val = hs->pool[hs->offset[0]++];
		244	val ^= hs->pool[hs->offset[1]++];
		245
		246	memcpy( p, &val, use_len );
		247
		248	len -= use_len;
		249	p += use_len;
		250	}
		251
		252	return( 0 );
		253	}
		254
		255	#endif /* MBEDTLS_HAVEGE_C */

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