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mirror of https://github.com/veracrypt/VeraCrypt.git synced 2025-11-11 19:08:26 -06:00

Update Jitterentropy Library to version 2.2.0

This commit is contained in:
Mounir IDRASSI
2019-10-30 12:18:20 +01:00
parent 3565cb1afe
commit 6252d96b0d
3 changed files with 332 additions and 184 deletions

View File

@@ -1,7 +1,7 @@
/* /*
* Non-physical true random number generator based on timing jitter. * Non-physical true random number generator based on timing jitter.
* *
* Copyright Stephan Mueller <smueller@chronox.de>, 2013 * Copyright Stephan Mueller <smueller@chronox.de>, 2013 - 2019
* *
* License * License
* ======= * =======
@@ -35,7 +35,7 @@
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
e USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE. * DAMAGE.
*/ */

View File

@@ -1,7 +1,7 @@
/* /*
* Non-physical true random number generator based on timing jitter. * Non-physical true random number generator based on timing jitter.
* *
* Copyright Stephan Mueller <smueller@chronox.de>, 2014 - 2018 * Copyright Stephan Mueller <smueller@chronox.de>, 2014 - 2019
* *
* Design * Design
* ====== * ======
@@ -11,7 +11,7 @@
* Interface * Interface
* ========= * =========
* *
* See documentation in doc/ folder. * See documentation in jitterentropy(3) man page.
* *
* License * License
* ======= * =======
@@ -51,6 +51,8 @@
/* Adapted for VeraCrypt */ /* Adapted for VeraCrypt */
#include <stdint.h>
#undef _FORTIFY_SOURCE #undef _FORTIFY_SOURCE
#ifdef _MSC_VER #ifdef _MSC_VER
@@ -66,23 +68,22 @@
#include "jitterentropy.h" #include "jitterentropy.h"
#ifndef CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT #ifdef __OPTIMIZE__
/* only check optimization in a compilation for real work */ #error "The CPU Jitter random number generator must not be compiled with optimizations. See documentation. Use the compiler switch -O0 for compiling jitterentropy-base.c."
#ifdef __OPTIMIZE__
#error "The CPU Jitter random number generator must not be compiled with optimizations. See documentation. Use the compiler switch -O0 for compiling jitterentropy-base.c."
#endif
#endif #endif
#define MAJVERSION 2 /* API / ABI incompatible changes, functional changes that #define MAJVERSION 2 /* API / ABI incompatible changes, functional changes that
* require consumer to be updated (as long as this number * require consumer to be updated (as long as this number
* is zero, the API is not considered stable and can * is zero, the API is not considered stable and can
* change without a bump of the major version) */ * change without a bump of the major version) */
#define MINVERSION 1 /* API compatible, ABI may change, functional #define MINVERSION 2 /* API compatible, ABI may change, functional
* enhancements only, consumer can be left unchanged if * enhancements only, consumer can be left unchanged if
* enhancements are not considered */ * enhancements are not considered */
#define PATCHLEVEL 2 /* API / ABI compatible, no functional changes, no #define PATCHLEVEL 0 /* API / ABI compatible, no functional changes, no
* enhancements, bug fixes only */ * enhancements, bug fixes only */
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
/** /**
* jent_version() - Return machine-usable version number of jent library * jent_version() - Return machine-usable version number of jent library
* *
@@ -94,7 +95,7 @@
* The result of this function can be used in comparing the version number * The result of this function can be used in comparing the version number
* in a calling program if version-specific calls need to be make. * in a calling program if version-specific calls need to be make.
* *
* Return: Version number of jitterentropy library * @return Version number of jitterentropy library
*/ */
JENT_PRIVATE_STATIC JENT_PRIVATE_STATIC
unsigned int jent_version(void) unsigned int jent_version(void)
@@ -108,15 +109,206 @@ unsigned int jent_version(void)
return version; return version;
} }
/***************************************************************************
* Adaptive Proportion Test
*
* This test complies with SP800-90B section 4.4.2.
***************************************************************************/
/**
* Reset the APT counter
*
* @ec [in] Reference to entropy collector
*/
static void jent_apt_reset(struct rand_data *ec, unsigned int delta_masked)
{
/* Reset APT counter */
ec->apt_count = 0;
ec->apt_base = delta_masked;
ec->apt_observations = 0;
}
/**
* Insert a new entropy event into APT
*
* @ec [in] Reference to entropy collector
* @delta_masked [in] Masked time delta to process
*/
static void jent_apt_insert(struct rand_data *ec, unsigned int delta_masked)
{
/* Initialize the base reference */
if (!ec->apt_base_set) {
ec->apt_base = delta_masked;
ec->apt_base_set = 1;
return;
}
if (delta_masked == ec->apt_base) {
ec->apt_count++;
if (ec->apt_count >= JENT_APT_CUTOFF)
ec->health_failure = 1;
}
ec->apt_observations++;
if (ec->apt_observations >= JENT_APT_WINDOW_SIZE)
jent_apt_reset(ec, delta_masked);
}
/***************************************************************************
* Stuck Test and its use as Repetition Count Test
*
* The Jitter RNG uses an enhanced version of the Repetition Count Test
* (RCT) specified in SP800-90B section 4.4.1. Instead of counting identical
* back-to-back values, the input to the RCT is the counting of the stuck
* values during the generation of one Jitter RNG output block.
*
* The RCT is applied with an alpha of 2^{-30} compliant to FIPS 140-2 IG 9.8.
*
* During the counting operation, the Jitter RNG always calculates the RCT
* cut-off value of C. If that value exceeds the allowed cut-off value,
* the Jitter RNG output block will be calculated completely but discarded at
* the end. The caller of the Jitter RNG is informed with an error code.
***************************************************************************/
/**
* Repetition Count Test as defined in SP800-90B section 4.4.1
*
* @ec [in] Reference to entropy collector
* @stuck [in] Indicator whether the value is stuck
*/
static void jent_rct_insert(struct rand_data *ec, int stuck)
{
/*
* If we have a count less than zero, a previous RCT round identified
* a failure. We will not overwrite it.
*/
if (ec->rct_count < 0)
return;
if (stuck) {
ec->rct_count++;
/*
* The cutoff value is based on the following consideration:
* alpha = 2^-30 as recommended in FIPS 140-2 IG 9.8.
* In addition, we require an entropy value H of 1/OSR as this
* is the minimum entropy required to provide full entropy.
* Note, we collect 64 * OSR deltas for inserting them into
* the entropy pool which should then have (close to) 64 bits
* of entropy.
*
* Note, ec->rct_count (which equals to value B in the pseudo
* code of SP800-90B section 4.4.1) starts with zero. Hence
* we need to subtract one from the cutoff value as calculated
* following SP800-90B.
*/
if ((unsigned int)ec->rct_count >= (30 * ec->osr)) {
ec->rct_count = -1;
ec->health_failure = 1;
}
} else {
ec->rct_count = 0;
}
}
/**
* Is there an RCT health test failure?
*
* @ec [in] Reference to entropy collector
*
* @return
* 0 No health test failure
* 1 Permanent health test failure
*/
static int jent_rct_failure(struct rand_data *ec)
{
if (ec->rct_count < 0)
return 1;
return 0;
}
#ifdef _MSC_VER
static
#endif
VC_INLINE uint64_t jent_delta(uint64_t prev, uint64_t next)
{
return (prev < next) ? (next - prev) : (UINT64_MAX - prev + 1 + next);
}
/**
* Stuck test by checking the:
* 1st derivative of the jitter measurement (time delta)
* 2nd derivative of the jitter measurement (delta of time deltas)
* 3rd derivative of the jitter measurement (delta of delta of time deltas)
*
* All values must always be non-zero.
*
* @ec [in] Reference to entropy collector
* @current_delta [in] Jitter time delta
*
* @return
* 0 jitter measurement not stuck (good bit)
* 1 jitter measurement stuck (reject bit)
*/
static int jent_stuck(struct rand_data *ec, uint64_t current_delta)
{
uint64_t delta2 = jent_delta(ec->last_delta, current_delta);
uint64_t delta3 = jent_delta(ec->last_delta2, delta2);
unsigned int delta_masked = current_delta & JENT_APT_WORD_MASK;
ec->last_delta = current_delta;
ec->last_delta2 = delta2;
/*
* Insert the result of the comparison of two back-to-back time
* deltas.
*/
jent_apt_insert(ec, delta_masked);
if (!current_delta || !delta2 || !delta3) {
/* RCT with a stuck bit */
jent_rct_insert(ec, 1);
return 1;
}
/* RCT with a non-stuck bit */
jent_rct_insert(ec, 0);
return 0;
}
/**
* Report any health test failures
*
* @ec [in] Reference to entropy collector
*
* @return
* 0 No health test failure
* 1 Permanent health test failure
*/
static int jent_health_failure(struct rand_data *ec)
{
/* Test is only enabled in FIPS mode */
if (!ec->fips_enabled)
return 0;
return ec->health_failure;
}
/***************************************************************************
* Noise sources
***************************************************************************/
/** /**
* Update of the loop count used for the next round of * Update of the loop count used for the next round of
* an entropy collection. * an entropy collection.
* *
* Input: * @ec [in] entropy collector struct -- may be NULL
* @ec entropy collector struct -- may be NULL * @bits [in] is the number of low bits of the timer to consider
* @bits is the number of low bits of the timer to consider * @min [in] is the number of bits we shift the timer value to the right at
* @min is the number of bits we shift the timer value to the right at * the end to make sure we have a guaranteed minimum value
* the end to make sure we have a guaranteed minimum value
* *
* @return Newly calculated loop counter * @return Newly calculated loop counter
*/ */
@@ -151,10 +343,6 @@ static uint64_t jent_loop_shuffle(struct rand_data *ec,
return (shuffle + (1<<min)); return (shuffle + (1<<min));
} }
/***************************************************************************
* Noise sources
***************************************************************************/
/** /**
* CPU Jitter noise source -- this is the noise source based on the CPU * CPU Jitter noise source -- this is the noise source based on the CPU
* execution time jitter * execution time jitter
@@ -165,30 +353,27 @@ static uint64_t jent_loop_shuffle(struct rand_data *ec,
* The code is deliberately inefficient with respect to the bit shifting * The code is deliberately inefficient with respect to the bit shifting
* and shall stay that way. This function is the root cause why the code * and shall stay that way. This function is the root cause why the code
* shall be compiled without optimization. This function not only acts as * shall be compiled without optimization. This function not only acts as
* folding operation, but this function's execution is used to measure * LFSR operation, but this function's execution is used to measure
* the CPU execution time jitter. Any change to the loop in this function * the CPU execution time jitter. Any change to the loop in this function
* implies that careful retesting must be done. * implies that careful retesting must be done.
* *
* Input: * @ec [in] entropy collector struct -- may be NULL
* @ec entropy collector struct -- may be NULL * @time [in] time stamp to be injected
* @time time stamp to be injected * @loop_cnt [in] if a value not equal to 0 is set, use the given value as
* @loop_cnt if a value not equal to 0 is set, use the given value as number of * number of loops to perform the LFSR
* loops to perform the folding
* *
* Output: * Output:
* updated ec->data * updated ec->data
*
* @return Number of loops the folding operation is performed
*/ */
static uint64_t jent_lfsr_time(struct rand_data *ec, uint64_t time, static void jent_lfsr_time(struct rand_data *ec, uint64_t time,
uint64_t loop_cnt) uint64_t loop_cnt, int stuck)
{ {
unsigned int i; unsigned int i;
uint64_t j = 0; uint64_t j = 0;
uint64_t new = 0; uint64_t new = 0;
#define MAX_FOLD_LOOP_BIT 4 #define MAX_FOLD_LOOP_BIT 4
#define MIN_FOLD_LOOP_BIT 0 #define MIN_FOLD_LOOP_BIT 0
uint64_t fold_loop_cnt = uint64_t lfsr_loop_cnt =
jent_loop_shuffle(ec, MAX_FOLD_LOOP_BIT, MIN_FOLD_LOOP_BIT); jent_loop_shuffle(ec, MAX_FOLD_LOOP_BIT, MIN_FOLD_LOOP_BIT);
/* /*
@@ -196,8 +381,8 @@ static uint64_t jent_lfsr_time(struct rand_data *ec, uint64_t time,
* needed during runtime * needed during runtime
*/ */
if (loop_cnt) if (loop_cnt)
fold_loop_cnt = loop_cnt; lfsr_loop_cnt = loop_cnt;
for (j = 0; j < fold_loop_cnt; j++) { for (j = 0; j < lfsr_loop_cnt; j++) {
new = ec->data; new = ec->data;
for (i = 1; (DATA_SIZE_BITS) >= i; i++) { for (i = 1; (DATA_SIZE_BITS) >= i; i++) {
uint64_t tmp = time << (DATA_SIZE_BITS - i); uint64_t tmp = time << (DATA_SIZE_BITS - i);
@@ -224,9 +409,17 @@ static uint64_t jent_lfsr_time(struct rand_data *ec, uint64_t time,
new ^= tmp; new ^= tmp;
} }
} }
ec->data = new;
return fold_loop_cnt; /*
* If the time stamp is stuck, do not finally insert the value into
* the entropy pool. Although this operation should not do any harm
* even when the time stamp has no entropy, SP800-90B requires that
* any conditioning operation (SP800-90B considers the LFSR to be a
* conditioning operation) to have an identical amount of input
* data according to section 3.1.5.
*/
if (!stuck)
ec->data = new;
} }
/** /**
@@ -247,16 +440,13 @@ static uint64_t jent_lfsr_time(struct rand_data *ec, uint64_t time,
* to reliably access either L3 or memory, the ec->mem memory must be quite * to reliably access either L3 or memory, the ec->mem memory must be quite
* large which is usually not desirable. * large which is usually not desirable.
* *
* Input: * @ec [in] Reference to the entropy collector with the memory access data -- if
* @ec Reference to the entropy collector with the memory access data -- if * the reference to the memory block to be accessed is NULL, this noise
* the reference to the memory block to be accessed is NULL, this noise * source is disabled
* source is disabled * @loop_cnt [in] if a value not equal to 0 is set, use the given value as
* @loop_cnt if a value not equal to 0 is set, use the given value as number of * number of loops to perform the folding
* loops to perform the folding
*
* @return Number of memory access operations
*/ */
static unsigned int jent_memaccess(struct rand_data *ec, uint64_t loop_cnt) static void jent_memaccess(struct rand_data *ec, uint64_t loop_cnt)
{ {
unsigned int wrap = 0; unsigned int wrap = 0;
uint64_t i = 0; uint64_t i = 0;
@@ -266,7 +456,7 @@ static unsigned int jent_memaccess(struct rand_data *ec, uint64_t loop_cnt)
jent_loop_shuffle(ec, MAX_ACC_LOOP_BIT, MIN_ACC_LOOP_BIT); jent_loop_shuffle(ec, MAX_ACC_LOOP_BIT, MIN_ACC_LOOP_BIT);
if (NULL == ec || NULL == ec->mem) if (NULL == ec || NULL == ec->mem)
return 0; return;
wrap = ec->memblocksize * ec->memblocks; wrap = ec->memblocksize * ec->memblocks;
/* /*
@@ -292,43 +482,11 @@ static unsigned int jent_memaccess(struct rand_data *ec, uint64_t loop_cnt)
ec->memlocation = ec->memlocation + ec->memblocksize - 1; ec->memlocation = ec->memlocation + ec->memblocksize - 1;
ec->memlocation = ec->memlocation % wrap; ec->memlocation = ec->memlocation % wrap;
} }
return i;
} }
/*************************************************************************** /***************************************************************************
* Start of entropy processing logic * Start of entropy processing logic
***************************************************************************/ ***************************************************************************/
/**
* Stuck test by checking the:
* 1st derivation of the jitter measurement (time delta)
* 2nd derivation of the jitter measurement (delta of time deltas)
* 3rd derivation of the jitter measurement (delta of delta of time deltas)
*
* All values must always be non-zero.
*
* Input:
* @ec Reference to entropy collector
* @current_delta Jitter time delta
*
* @return
* 0 jitter measurement not stuck (good bit)
* 1 jitter measurement stuck (reject bit)
*/
static int jent_stuck(struct rand_data *ec, uint64_t current_delta)
{
int64_t delta2 = ec->last_delta - current_delta;
int64_t delta3 = delta2 - ec->last_delta2;
ec->last_delta = current_delta;
ec->last_delta2 = delta2;
if (!current_delta || !delta2 || !delta3)
return 1;
return 0;
}
/** /**
* This is the heart of the entropy generation: calculate time deltas and * This is the heart of the entropy generation: calculate time deltas and
* use the CPU jitter in the time deltas. The jitter is injected into the * use the CPU jitter in the time deltas. The jitter is injected into the
@@ -338,8 +496,7 @@ static int jent_stuck(struct rand_data *ec, uint64_t current_delta)
* of this function! This can be done by calling this function * of this function! This can be done by calling this function
* and not using its result. * and not using its result.
* *
* Input: * @ec [in] Reference to entropy collector
* @entropy_collector Reference to entropy collector
* *
* @return: result of stuck test * @return: result of stuck test
*/ */
@@ -347,6 +504,7 @@ static int jent_measure_jitter(struct rand_data *ec)
{ {
uint64_t time = 0; uint64_t time = 0;
uint64_t current_delta = 0; uint64_t current_delta = 0;
int stuck;
/* Invoke one noise source before time measurement to add variations */ /* Invoke one noise source before time measurement to add variations */
jent_memaccess(ec, 0); jent_memaccess(ec, 0);
@@ -356,22 +514,23 @@ static int jent_measure_jitter(struct rand_data *ec)
* invocation to measure the timing variations * invocation to measure the timing variations
*/ */
jent_get_nstime(&time); jent_get_nstime(&time);
current_delta = time - ec->prev_time; current_delta = jent_delta(ec->prev_time, time);
ec->prev_time = time; ec->prev_time = time;
/* Now call the next noise sources which also injects the data */
jent_lfsr_time(ec, current_delta, 0);
/* Check whether we have a stuck measurement. */ /* Check whether we have a stuck measurement. */
return jent_stuck(ec, current_delta); stuck = jent_stuck(ec, current_delta);
/* Now call the next noise sources which also injects the data */
jent_lfsr_time(ec, current_delta, 0, stuck);
return stuck;
} }
/** /**
* Generator of one 64 bit random number * Generator of one 64 bit random number
* Function fills rand_data->data * Function fills rand_data->data
* *
* Input: * @ec [in] Reference to entropy collector
* @ec Reference to entropy collector
*/ */
static void jent_gen_entropy(struct rand_data *ec) static void jent_gen_entropy(struct rand_data *ec)
{ {
@@ -394,41 +553,6 @@ static void jent_gen_entropy(struct rand_data *ec)
} }
} }
/**
* The continuous test required by FIPS 140-2 -- the function automatically
* primes the test if needed.
*
* Return:
* 0 if FIPS test passed
* < 0 if FIPS test failed
*/
static int jent_fips_test(struct rand_data *ec)
{
if (ec->fips_enabled == -1)
return 0;
if (ec->fips_enabled == 0) {
if (!jent_fips_enabled()) {
ec->fips_enabled = -1;
return 0;
} else
ec->fips_enabled = 1;
}
/* prime the FIPS test */
if (!ec->old_data) {
ec->old_data = ec->data;
jent_gen_entropy(ec);
}
if (ec->data == ec->old_data)
return -1;
ec->old_data = ec->data;
return 0;
}
/** /**
* Entry function: Obtain entropy for the caller. * Entry function: Obtain entropy for the caller.
* *
@@ -439,18 +563,18 @@ static int jent_fips_test(struct rand_data *ec)
* This function truncates the last 64 bit entropy value output to the exact * This function truncates the last 64 bit entropy value output to the exact
* size specified by the caller. * size specified by the caller.
* *
* Input: * @ec [in] Reference to entropy collector
* @ec Reference to entropy collector * @data [out] pointer to buffer for storing random data -- buffer must
* @data pointer to buffer for storing random data -- buffer must already * already exist
* exist * @len [in] size of the buffer, specifying also the requested number of random
* @len size of the buffer, specifying also the requested number of random * in bytes
* in bytes
* *
* @return number of bytes returned when request is fulfilled or an error * @return number of bytes returned when request is fulfilled or an error
* *
* The following error codes can occur: * The following error codes can occur:
* -1 entropy_collector is NULL * -1 entropy_collector is NULL
* -2 FIPS test failed * -2 RCT failed
* -3 Chi-Squared test failed
*/ */
JENT_PRIVATE_STATIC JENT_PRIVATE_STATIC
ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len) ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len)
@@ -465,8 +589,13 @@ ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len)
size_t tocopy; size_t tocopy;
jent_gen_entropy(ec); jent_gen_entropy(ec);
if (jent_fips_test(ec))
return -2; if (jent_health_failure(ec)) {
if (jent_rct_failure(ec))
return -2;
else
return -3;
}
if ((DATA_SIZE_BITS / 8) < len) if ((DATA_SIZE_BITS / 8) < len)
tocopy = (DATA_SIZE_BITS / 8); tocopy = (DATA_SIZE_BITS / 8);
@@ -533,11 +662,8 @@ struct rand_data *jent_entropy_collector_alloc(unsigned int osr,
osr = 1; /* minimum sampling rate is 1 */ osr = 1; /* minimum sampling rate is 1 */
entropy_collector->osr = osr; entropy_collector->osr = osr;
entropy_collector->stir = 1; if (jent_fips_enabled())
if (flags & JENT_DISABLE_STIR) entropy_collector->fips_enabled = 1;
entropy_collector->stir = 0;
if (flags & JENT_DISABLE_UNBIAS)
entropy_collector->disable_unbias = 1;
/* fill the data pad with non-zero values */ /* fill the data pad with non-zero values */
jent_gen_entropy(entropy_collector); jent_gen_entropy(entropy_collector);
@@ -563,6 +689,7 @@ int jent_entropy_init(void)
int i; int i;
uint64_t delta_sum = 0; uint64_t delta_sum = 0;
uint64_t old_delta = 0; uint64_t old_delta = 0;
unsigned int nonstuck = 0;
int time_backwards = 0; int time_backwards = 0;
int count_mod = 0; int count_mod = 0;
int count_stuck = 0; int count_stuck = 0;
@@ -570,6 +697,11 @@ int jent_entropy_init(void)
memset(&ec, 0, sizeof(ec)); memset(&ec, 0, sizeof(ec));
/* Required for RCT */
ec.osr = 1;
if (jent_fips_enabled())
ec.fips_enabled = 1;
/* We could perform statistical tests here, but the problem is /* We could perform statistical tests here, but the problem is
* that we only have a few loop counts to do testing. These * that we only have a few loop counts to do testing. These
* loop counts may show some slight skew and we produce * loop counts may show some slight skew and we produce
@@ -591,8 +723,10 @@ int jent_entropy_init(void)
/* /*
* TESTLOOPCOUNT needs some loops to identify edge systems. 100 is * TESTLOOPCOUNT needs some loops to identify edge systems. 100 is
* definitely too little. * definitely too little.
*
* SP800-90B requires at least 1024 initial test cycles.
*/ */
#define TESTLOOPCOUNT 300 #define TESTLOOPCOUNT 1024
#define CLEARCACHE 100 #define CLEARCACHE 100
for (i = 0; (TESTLOOPCOUNT + CLEARCACHE) > i; i++) { for (i = 0; (TESTLOOPCOUNT + CLEARCACHE) > i; i++) {
uint64_t time = 0; uint64_t time = 0;
@@ -604,13 +738,14 @@ int jent_entropy_init(void)
/* Invoke core entropy collection logic */ /* Invoke core entropy collection logic */
jent_get_nstime(&time); jent_get_nstime(&time);
ec.prev_time = time; ec.prev_time = time;
jent_lfsr_time(&ec, time, 0); jent_memaccess(&ec, 0);
jent_lfsr_time(&ec, time, 0, 0);
jent_get_nstime(&time2); jent_get_nstime(&time2);
/* test whether timer works */ /* test whether timer works */
if (!time || !time2) if (!time || !time2)
return ENOTIME; return ENOTIME;
delta = time2 - time; delta = jent_delta(time, time2);
/* /*
* test whether timer is fine grained enough to provide * test whether timer is fine grained enough to provide
* delta even when called shortly after each other -- this * delta even when called shortly after each other -- this
@@ -633,13 +768,35 @@ int jent_entropy_init(void)
if (stuck) if (stuck)
count_stuck++; count_stuck++;
else {
nonstuck++;
/*
* Ensure that the APT succeeded.
*
* With the check below that count_stuck must be less
* than 10% of the overall generated raw entropy values
* it is guaranteed that the APT is invoked at
* floor((TESTLOOPCOUNT * 0.9) / 64) == 14 times.
*/
if ((nonstuck % JENT_APT_WINDOW_SIZE) == 0) {
jent_apt_reset(&ec,
delta & JENT_APT_WORD_MASK);
if (jent_health_failure(&ec))
return EHEALTH;
}
}
/* Validate RCT */
if (jent_rct_failure(&ec))
return ERCT;
/* test whether we have an increasing timer */ /* test whether we have an increasing timer */
if (!(time2 > time)) if (!(time2 > time))
time_backwards++; time_backwards++;
/* use 32 bit value to ensure compilation on 32 bit arches */ /* use 32 bit value to ensure compilation on 32 bit arches */
lowdelta = time2 - time; lowdelta = (uint64_t)time2 - (uint64_t)time;
if (!(lowdelta % 100)) if (!(lowdelta % 100))
count_mod++; count_mod++;
@@ -686,32 +843,8 @@ int jent_entropy_init(void)
* If we have more than 90% stuck results, then this Jitter RNG is * If we have more than 90% stuck results, then this Jitter RNG is
* likely to not work well. * likely to not work well.
*/ */
if (JENT_STUCK_INIT_THRES(TESTLOOPCOUNT) < count_stuck) if ((TESTLOOPCOUNT/10 * 9) < count_stuck)
return ESTUCK; return ESTUCK;
return 0; return 0;
} }
/***************************************************************************
* Statistical test logic not compiled for regular operation
***************************************************************************/
#ifdef CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT
/*
* Statistical test: return the time duration for the folding operation. If min
* is set, perform the given number of LFSR ops. Otherwise, allow the
* loop count shuffling to define the number of LFSR ops.
*/
JENT_PRIVATE_STATIC
uint64_t jent_lfsr_var_stat(struct rand_data *ec, unsigned int min)
{
uint64_t time = 0;
uint64_t time2 = 0;
jent_get_nstime(&time);
jent_memaccess(ec, min);
jent_lfsr_time(ec, time, min);
jent_get_nstime(&time2);
return ((time2 - time));
}
#endif /* CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT */

View File

@@ -1,7 +1,7 @@
/* /*
* Non-physical true random number generator based on timing jitter. * Non-physical true random number generator based on timing jitter.
* *
* Copyright Stephan Mueller <smueller@chronox.de>, 2014 * Copyright Stephan Mueller <smueller@chronox.de>, 2014 - 2019
* *
* License * License
* ======= * =======
@@ -53,32 +53,45 @@ struct rand_data
* of the RNG are marked as SENSITIVE. A user must not * of the RNG are marked as SENSITIVE. A user must not
* access that information while the RNG executes its loops to * access that information while the RNG executes its loops to
* calculate the next random value. */ * calculate the next random value. */
uint64_t data; /* SENSITIVE Actual random number */ uint64_t data; /* SENSITIVE Actual random number */
uint64_t old_data; /* SENSITIVE Previous random number */ uint64_t prev_time; /* SENSITIVE Previous time stamp */
uint64_t prev_time; /* SENSITIVE Previous time stamp */
#define DATA_SIZE_BITS ((sizeof(uint64_t)) * 8) #define DATA_SIZE_BITS ((sizeof(uint64_t)) * 8)
uint64_t last_delta; /* SENSITIVE stuck test */ uint64_t last_delta; /* SENSITIVE stuck test */
int64_t last_delta2; /* SENSITIVE stuck test */ uint64_t last_delta2; /* SENSITIVE stuck test */
unsigned int osr; /* Oversample rate */ unsigned int osr; /* Oversampling rate */
int fips_enabled; /* FIPS enabled? */
unsigned int stir:1; /* Post-processing stirring */
unsigned int disable_unbias:1; /* Deactivate Von-Neuman unbias */
#define JENT_MEMORY_BLOCKS 64 #define JENT_MEMORY_BLOCKS 64
#define JENT_MEMORY_BLOCKSIZE 32 #define JENT_MEMORY_BLOCKSIZE 32
#define JENT_MEMORY_ACCESSLOOPS 128 #define JENT_MEMORY_ACCESSLOOPS 128
#define JENT_MEMORY_SIZE (JENT_MEMORY_BLOCKS*JENT_MEMORY_BLOCKSIZE) #define JENT_MEMORY_SIZE (JENT_MEMORY_BLOCKS*JENT_MEMORY_BLOCKSIZE)
unsigned char *mem; /* Memory access location with size of unsigned char *mem; /* Memory access location with size of
* memblocks * memblocksize */ * memblocks * memblocksize */
unsigned int memlocation; /* Pointer to byte in *mem */ unsigned int memlocation; /* Pointer to byte in *mem */
unsigned int memblocks; /* Number of memory blocks in *mem */ unsigned int memblocks; /* Number of memory blocks in *mem */
unsigned int memblocksize; /* Size of one memory block in bytes */ unsigned int memblocksize; /* Size of one memory block in bytes */
unsigned int memaccessloops; /* Number of memory accesses per random unsigned int memaccessloops; /* Number of memory accesses per random
* bit generation */ * bit generation */
/* Repetition Count Test */
int rct_count; /* Number of stuck values */
/* Adaptive Proportion Test for a significance level of 2^-30 */
#define JENT_APT_CUTOFF 325 /* Taken from SP800-90B sec 4.4.2 */
#define JENT_APT_WINDOW_SIZE 512 /* Data window size */
/* LSB of time stamp to process */
#define JENT_APT_LSB 16
#define JENT_APT_WORD_MASK (JENT_APT_LSB - 1)
unsigned int apt_observations; /* Number of collected observations */
unsigned int apt_count; /* APT counter */
unsigned int apt_base; /* APT base reference */
unsigned int apt_base_set:1; /* APT base reference set? */
unsigned int fips_enabled:1;
unsigned int health_failure:1; /* Permanent health failure */
}; };
/* Flags that can be used to initialize the RNG */ /* Flags that can be used to initialize the RNG */
#define JENT_DISABLE_STIR (1<<0) /* Disable stirring the entropy pool */ #define JENT_DISABLE_STIR (1<<0) /* UNUSED */
#define JENT_DISABLE_UNBIAS (1<<1) /* Disable the Von-Neuman Unbiaser */ #define JENT_DISABLE_UNBIAS (1<<1) /* UNUSED */
#define JENT_DISABLE_MEMORY_ACCESS (1<<2) /* Disable memory access for more #define JENT_DISABLE_MEMORY_ACCESS (1<<2) /* Disable memory access for more
entropy, saves MEMORY_SIZE RAM for entropy, saves MEMORY_SIZE RAM for
entropy collector */ entropy collector */
@@ -137,6 +150,8 @@ unsigned int jent_version(void);
#define EMINVARVAR 6 /* Timer variations of variations is too small */ #define EMINVARVAR 6 /* Timer variations of variations is too small */
#define EPROGERR 7 /* Programming error */ #define EPROGERR 7 /* Programming error */
#define ESTUCK 8 /* Too many stuck results during init. */ #define ESTUCK 8 /* Too many stuck results during init. */
#define EHEALTH 9 /* Health test failed during initialization */
#define ERCT 10 /* RCT failed during initialization */
/* -- BEGIN statistical test functions only complied with CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT -- */ /* -- BEGIN statistical test functions only complied with CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT -- */