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Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/external/mbedtls/library/havege.c')
| -rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/external/mbedtls/library/havege.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/external/mbedtls/library/havege.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/mbedtls/library/havege.c new file mode 100644 index 0000000..2b75ef7 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/mbedtls/library/havege.c @@ -0,0 +1,245 @@ +/** + * \brief HAVEGE: HArdware Volatile Entropy Gathering and Expansion + * + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * This file is part of mbed TLS (https://tls.mbed.org) + */ +/* + * The HAVEGE RNG was designed by Andre Seznec in 2002. + * + * http://www.irisa.fr/caps/projects/hipsor/publi.php + * + * Contact: seznec(at)irisa_dot_fr - orocheco(at)irisa_dot_fr + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#if defined(MBEDTLS_HAVEGE_C) + +#include "mbedtls/havege.h" +#include "mbedtls/timing.h" + +#include <string.h> + +/* Implementation that should never be optimized out by the compiler */ +static void mbedtls_zeroize( void *v, size_t n ) { + volatile unsigned char *p = v; while( n-- ) *p++ = 0; +} + +/* ------------------------------------------------------------------------ + * On average, one iteration accesses two 8-word blocks in the havege WALK + * table, and generates 16 words in the RES array. + * + * The data read in the WALK table is updated and permuted after each use. + * The result of the hardware clock counter read is used for this update. + * + * 25 conditional tests are present. The conditional tests are grouped in + * two nested groups of 12 conditional tests and 1 test that controls the + * permutation; on average, there should be 6 tests executed and 3 of them + * should be mispredicted. + * ------------------------------------------------------------------------ + */ + +#define SWAP(X,Y) { int *T = X; X = Y; Y = T; } + +#define TST1_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1; +#define TST2_ENTER if( PTEST & 1 ) { PTEST ^= 3; PTEST >>= 1; + +#define TST1_LEAVE U1++; } +#define TST2_LEAVE U2++; } + +#define ONE_ITERATION \ + \ + PTEST = PT1 >> 20; \ + \ + TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \ + TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \ + TST1_ENTER TST1_ENTER TST1_ENTER TST1_ENTER \ + \ + TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \ + TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \ + TST1_LEAVE TST1_LEAVE TST1_LEAVE TST1_LEAVE \ + \ + PTX = (PT1 >> 18) & 7; \ + PT1 &= 0x1FFF; \ + PT2 &= 0x1FFF; \ + CLK = (int) mbedtls_timing_hardclock(); \ + \ + i = 0; \ + A = &WALK[PT1 ]; RES[i++] ^= *A; \ + B = &WALK[PT2 ]; RES[i++] ^= *B; \ + C = &WALK[PT1 ^ 1]; RES[i++] ^= *C; \ + D = &WALK[PT2 ^ 4]; RES[i++] ^= *D; \ + \ + IN = (*A >> (1)) ^ (*A << (31)) ^ CLK; \ + *A = (*B >> (2)) ^ (*B << (30)) ^ CLK; \ + *B = IN ^ U1; \ + *C = (*C >> (3)) ^ (*C << (29)) ^ CLK; \ + *D = (*D >> (4)) ^ (*D << (28)) ^ CLK; \ + \ + A = &WALK[PT1 ^ 2]; RES[i++] ^= *A; \ + B = &WALK[PT2 ^ 2]; RES[i++] ^= *B; \ + C = &WALK[PT1 ^ 3]; RES[i++] ^= *C; \ + D = &WALK[PT2 ^ 6]; RES[i++] ^= *D; \ + \ + if( PTEST & 1 ) SWAP( A, C ); \ + \ + IN = (*A >> (5)) ^ (*A << (27)) ^ CLK; \ + *A = (*B >> (6)) ^ (*B << (26)) ^ CLK; \ + *B = IN; CLK = (int) mbedtls_timing_hardclock(); \ + *C = (*C >> (7)) ^ (*C << (25)) ^ CLK; \ + *D = (*D >> (8)) ^ (*D << (24)) ^ CLK; \ + \ + A = &WALK[PT1 ^ 4]; \ + B = &WALK[PT2 ^ 1]; \ + \ + PTEST = PT2 >> 1; \ + \ + PT2 = (RES[(i - 8) ^ PTY] ^ WALK[PT2 ^ PTY ^ 7]); \ + PT2 = ((PT2 & 0x1FFF) & (~8)) ^ ((PT1 ^ 8) & 0x8); \ + PTY = (PT2 >> 10) & 7; \ + \ + TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \ + TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \ + TST2_ENTER TST2_ENTER TST2_ENTER TST2_ENTER \ + \ + TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \ + TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \ + TST2_LEAVE TST2_LEAVE TST2_LEAVE TST2_LEAVE \ + \ + C = &WALK[PT1 ^ 5]; \ + D = &WALK[PT2 ^ 5]; \ + \ + RES[i++] ^= *A; \ + RES[i++] ^= *B; \ + RES[i++] ^= *C; \ + RES[i++] ^= *D; \ + \ + IN = (*A >> ( 9)) ^ (*A << (23)) ^ CLK; \ + *A = (*B >> (10)) ^ (*B << (22)) ^ CLK; \ + *B = IN ^ U2; \ + *C = (*C >> (11)) ^ (*C << (21)) ^ CLK; \ + *D = (*D >> (12)) ^ (*D << (20)) ^ CLK; \ + \ + A = &WALK[PT1 ^ 6]; RES[i++] ^= *A; \ + B = &WALK[PT2 ^ 3]; RES[i++] ^= *B; \ + C = &WALK[PT1 ^ 7]; RES[i++] ^= *C; \ + D = &WALK[PT2 ^ 7]; RES[i++] ^= *D; \ + \ + IN = (*A >> (13)) ^ (*A << (19)) ^ CLK; \ + *A = (*B >> (14)) ^ (*B << (18)) ^ CLK; \ + *B = IN; \ + *C = (*C >> (15)) ^ (*C << (17)) ^ CLK; \ + *D = (*D >> (16)) ^ (*D << (16)) ^ CLK; \ + \ + PT1 = ( RES[( i - 8 ) ^ PTX] ^ \ + WALK[PT1 ^ PTX ^ 7] ) & (~1); \ + PT1 ^= (PT2 ^ 0x10) & 0x10; \ + \ + for( n++, i = 0; i < 16; i++ ) \ + hs->pool[n % MBEDTLS_HAVEGE_COLLECT_SIZE] ^= RES[i]; + +/* + * Entropy gathering function + */ +static void havege_fill( mbedtls_havege_state *hs ) +{ + int i, n = 0; + int U1, U2, *A, *B, *C, *D; + int PT1, PT2, *WALK, RES[16]; + int PTX, PTY, CLK, PTEST, IN; + + WALK = hs->WALK; + PT1 = hs->PT1; + PT2 = hs->PT2; + + PTX = U1 = 0; + PTY = U2 = 0; + + (void)PTX; + + memset( RES, 0, sizeof( RES ) ); + + while( n < MBEDTLS_HAVEGE_COLLECT_SIZE * 4 ) + { + ONE_ITERATION + ONE_ITERATION + ONE_ITERATION + ONE_ITERATION + } + + hs->PT1 = PT1; + hs->PT2 = PT2; + + hs->offset[0] = 0; + hs->offset[1] = MBEDTLS_HAVEGE_COLLECT_SIZE / 2; +} + +/* + * HAVEGE initialization + */ +void mbedtls_havege_init( mbedtls_havege_state *hs ) +{ + memset( hs, 0, sizeof( mbedtls_havege_state ) ); + + havege_fill( hs ); +} + +void mbedtls_havege_free( mbedtls_havege_state *hs ) +{ + if( hs == NULL ) + return; + + mbedtls_zeroize( hs, sizeof( mbedtls_havege_state ) ); +} + +/* + * HAVEGE rand function + */ +int mbedtls_havege_random( void *p_rng, unsigned char *buf, size_t len ) +{ + int val; + size_t use_len; + mbedtls_havege_state *hs = (mbedtls_havege_state *) p_rng; + unsigned char *p = buf; + + while( len > 0 ) + { + use_len = len; + if( use_len > sizeof(int) ) + use_len = sizeof(int); + + if( hs->offset[1] >= MBEDTLS_HAVEGE_COLLECT_SIZE ) + havege_fill( hs ); + + val = hs->pool[hs->offset[0]++]; + val ^= hs->pool[hs->offset[1]++]; + + memcpy( p, &val, use_len ); + + len -= use_len; + p += use_len; + } + + return( 0 ); +} + +#endif /* MBEDTLS_HAVEGE_C */ |