Update Jitterentropy Library to version 2.2.0

author: Mounir IDRASSI <mounir.idrassi@idrix.fr> 2019-10-30 12:18:20 +0100
committer: Mounir IDRASSI <mounir.idrassi@idrix.fr> 2019-10-30 22:05:25 +0100
commit: 6252d96b0de2001b29596715c8f3345cc93324f7 (patch)
tree: a6829ea7bb3d169d97b82a50697db3b749c0d579 /src
parent: 3565cb1afe4f917422853e42d7dbe05526ab750b (diff)
download: VeraCrypt-6252d96b0de2001b29596715c8f3345cc93324f7.tar.gz
VeraCrypt-6252d96b0de2001b29596715c8f3345cc93324f7.zip
3 files changed, 331 insertions, 183 deletions
diff --git a/src/Crypto/jitterentropy-base-user.h b/src/Crypto/jitterentropy-base-user.h
index 3502dd4f..a4f5cb4e 100644
--- a/src/Crypto/jitterentropy-base-user.h
+++ b/src/Crypto/jitterentropy-base-user.h
@@ -1,7 +1,7 @@
 /*
  * 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
  * =======
@@ -35,7 +35,7 @@
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (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.
  */
 
diff --git a/src/Crypto/jitterentropy-base.c b/src/Crypto/jitterentropy-base.c
index 50544acb..241ea304 100644
--- a/src/Crypto/jitterentropy-base.c
+++ b/src/Crypto/jitterentropy-base.c
@@ -1,7 +1,7 @@
 /*
  * 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
  * ======
@@ -11,7 +11,7 @@
  * Interface
  * =========
  *
- * See documentation in doc/ folder.
+ * See documentation in jitterentropy(3) man page.
  *
  * License
  * =======
@@ -51,6 +51,8 @@
 
 /* Adapted for VeraCrypt */
 
+#include <stdint.h>
+
 #undef _FORTIFY_SOURCE
 
 #ifdef _MSC_VER
@@ -66,23 +68,22 @@
 
 #include "jitterentropy.h"
 
-#ifndef CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT
- /* only check optimization in a compilation for real work */
- #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
+#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
 
 #define MAJVERSION 2 /* API / ABI incompatible changes, functional changes that
 		      * require consumer to be updated (as long as this number
 		      * is zero, the API is not considered stable and can
 		      * 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 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 */
 
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
 /**
  * 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
  * 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
 unsigned int jent_version(void)
@@ -108,15 +109,206 @@ unsigned int jent_version(void)
 	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
  * an entropy collection.
  *
- * Input:
- * @ec entropy collector struct -- may be NULL
- * @bits is the number of low bits of the timer to consider
- * @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
+ * @ec [in] entropy collector struct -- may be NULL
+ * @bits [in] 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
+ *	     the end to make sure we have a guaranteed minimum value
  *
  * @return Newly calculated loop counter
  */
@@ -151,10 +343,6 @@ static uint64_t jent_loop_shuffle(struct rand_data *ec,
 	return (shuffle + (1<<min));
 }
 
-/***************************************************************************
- * Noise sources
- ***************************************************************************/
-
 /**
  * CPU Jitter noise source -- this is the noise source based on the CPU
  * 			      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
  * 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
- * 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
  * implies that careful retesting must be done.
  *
- * Input:
- * @ec entropy collector struct -- may be NULL
- * @time time stamp to be injected
- * @loop_cnt if a value not equal to 0 is set, use the given value as number of
- *	     loops to perform the folding
+ * @ec [in] entropy collector struct -- may be NULL
+ * @time [in] time stamp to be injected
+ * @loop_cnt [in] if a value not equal to 0 is set, use the given value as
+ *		  number of loops to perform the LFSR
  *
  * Output:
  * 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,
-			       uint64_t loop_cnt)
+static void jent_lfsr_time(struct rand_data *ec, uint64_t time,
+			   uint64_t loop_cnt, int stuck)
 {
 	unsigned int i;
 	uint64_t j = 0;
 	uint64_t new = 0;
 #define MAX_FOLD_LOOP_BIT 4
 #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);
 
 	/*
@@ -196,8 +381,8 @@ static uint64_t jent_lfsr_time(struct rand_data *ec, uint64_t time,
 	 * needed during runtime
 	 */
 	if (loop_cnt)
-		fold_loop_cnt = loop_cnt;
-	for (j = 0; j < fold_loop_cnt; j++) {
+		lfsr_loop_cnt = loop_cnt;
+	for (j = 0; j < lfsr_loop_cnt; j++) {
 		new = ec->data;
 		for (i = 1; (DATA_SIZE_BITS) >= i; 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;
 		}
 	}
-	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
  * large which is usually not desirable.
  *
- * Input:
- * @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
- *     source is disabled
- * @loop_cnt if a value not equal to 0 is set, use the given value as number of
- *	     loops to perform the folding
- *
- * @return Number of memory access operations
+ * @ec [in] Reference to the entropy collector with the memory access data -- if
+ *	    the reference to the memory block to be accessed is NULL, this noise
+ *	    source is disabled
+ * @loop_cnt [in] if a value not equal to 0 is set, use the given value as
+ *		  number of loops to perform the folding
  */
-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;
 	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);
 
 	if (NULL == ec || NULL == ec->mem)
-		return 0;
+		return;
 	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 % wrap;
 	}
-	return i;
 }
 
 /***************************************************************************
  * 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
  * 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
  * 	    and not using its result.
  *
- * Input:
- * @entropy_collector Reference to entropy collector
+ * @ec [in] Reference to entropy collector
  *
  * @return: result of stuck test
  */
@@ -347,6 +504,7 @@ static int jent_measure_jitter(struct rand_data *ec)
 {
 	uint64_t time = 0;
 	uint64_t current_delta = 0;
+	int stuck;
 
 	/* Invoke one noise source before time measurement to add variations */
 	jent_memaccess(ec, 0);
@@ -356,22 +514,23 @@ static int jent_measure_jitter(struct rand_data *ec)
 	 * invocation to measure the timing variations
 	 */
 	jent_get_nstime(&time);
-	current_delta = time - ec->prev_time;
+	current_delta = jent_delta(ec->prev_time, time);
 	ec->prev_time = time;
 
+	/* Check whether we have a stuck measurement. */
+	stuck = jent_stuck(ec, current_delta);
+
 	/* Now call the next noise sources which also injects the data */
-	jent_lfsr_time(ec, current_delta, 0);
+	jent_lfsr_time(ec, current_delta, 0, stuck);
 
-	/* Check whether we have a stuck measurement. */
-	return jent_stuck(ec, current_delta);
+	return stuck;
 }
 
 /**
  * Generator of one 64 bit random number
  * Function fills rand_data->data
  *
- * Input:
- * @ec Reference to entropy collector
+ * @ec [in] Reference to entropy collector
  */
 static void jent_gen_entropy(struct rand_data *ec)
 {
@@ -395,41 +554,6 @@ 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.
  *
  * This function invokes the entropy gathering logic as often to generate
@@ -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
  * size specified by the caller.
  *
- * Input:
- * @ec Reference to entropy collector
- * @data pointer to buffer for storing random data -- buffer must already
- *        exist
- * @len size of the buffer, specifying also the requested number of random
- *       in bytes
+ * @ec [in] Reference to entropy collector
+ * @data [out] pointer to buffer for storing random data -- buffer must
+ *	       already exist
+ * @len [in] size of the buffer, specifying also the requested number of random
+ *	     in bytes
  *
  * @return number of bytes returned when request is fulfilled or an error
  *
  * The following error codes can occur:
  *	-1	entropy_collector is NULL
- *	-2	FIPS test failed
+ *	-2	RCT failed
+ *	-3	Chi-Squared test failed
  */
 JENT_PRIVATE_STATIC
 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;
 
 		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)
 			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 */
 	entropy_collector->osr = osr;
 
-	entropy_collector->stir = 1;
-	if (flags & JENT_DISABLE_STIR)
-		entropy_collector->stir = 0;
-	if (flags & JENT_DISABLE_UNBIAS)
-		entropy_collector->disable_unbias = 1;
+	if (jent_fips_enabled())
+		entropy_collector->fips_enabled = 1;
 
 	/* fill the data pad with non-zero values */
 	jent_gen_entropy(entropy_collector);
@@ -563,6 +689,7 @@ int jent_entropy_init(void)
 	int i;
 	uint64_t delta_sum = 0;
 	uint64_t old_delta = 0;
+	unsigned int nonstuck = 0;
 	int time_backwards = 0;
 	int count_mod = 0;
 	int count_stuck = 0;
@@ -570,6 +697,11 @@ int jent_entropy_init(void)
 
 	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
 	 * that we only have a few loop counts to do testing. These
 	 * 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
 	 * definitely too little.
+	 *
+	 * SP800-90B requires at least 1024 initial test cycles.
 	 */
-#define TESTLOOPCOUNT 300
+#define TESTLOOPCOUNT 1024
 #define CLEARCACHE 100
 	for (i = 0; (TESTLOOPCOUNT + CLEARCACHE) > i; i++) {
 		uint64_t time = 0;
@@ -604,13 +738,14 @@ int jent_entropy_init(void)
 		/* Invoke core entropy collection logic */
 		jent_get_nstime(&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);
 
 		/* test whether timer works */
 		if (!time || !time2)
 			return ENOTIME;
-		delta = time2 - time;
+		delta = jent_delta(time, time2);
 		/*
 		 * test whether timer is fine grained enough to provide
 		 * delta even when called shortly after each other -- this
@@ -633,13 +768,35 @@ int jent_entropy_init(void)
 
 		if (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 */
 		if (!(time2 > time))
 			time_backwards++;
 
 		/* use 32 bit value to ensure compilation on 32 bit arches */
-		lowdelta = time2 - time;
+		lowdelta = (uint64_t)time2 - (uint64_t)time;
 		if (!(lowdelta % 100))
 			count_mod++;
 
@@ -686,32 +843,8 @@ int jent_entropy_init(void)
 	 * If we have more than 90% stuck results, then this Jitter RNG is
 	 * likely to not work well.
 	 */
-	if (JENT_STUCK_INIT_THRES(TESTLOOPCOUNT) < count_stuck)
+	if ((TESTLOOPCOUNT/10 * 9) < count_stuck)
 		return ESTUCK;
 
 	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 */
diff --git a/src/Crypto/jitterentropy.h b/src/Crypto/jitterentropy.h
index b6929933..3dd69017 100644
--- a/src/Crypto/jitterentropy.h
+++ b/src/Crypto/jitterentropy.h
@@ -1,7 +1,7 @@
 /*
  * 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
  * =======
@@ -53,32 +53,45 @@ struct rand_data
 	 * of the RNG are marked as SENSITIVE. A user must not
 	 * access that information while the RNG executes its loops to
 	 * calculate the next random value. */
-	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 data;			/* SENSITIVE Actual random number */
+	uint64_t prev_time;		/* SENSITIVE Previous time stamp */
 #define DATA_SIZE_BITS ((sizeof(uint64_t)) * 8)
-	uint64_t last_delta;	/* SENSITIVE stuck test */
-	int64_t last_delta2;	/* SENSITIVE stuck test */
-	unsigned int osr;	/* Oversample rate */
-	int fips_enabled;	/* FIPS enabled? */
-	unsigned int stir:1;		/* Post-processing stirring */
-	unsigned int disable_unbias:1;	/* Deactivate Von-Neuman unbias */
+	uint64_t last_delta;		/* SENSITIVE stuck test */
+	uint64_t last_delta2;		/* SENSITIVE stuck test */
+	unsigned int osr;		/* Oversampling rate */
 #define JENT_MEMORY_BLOCKS 64
 #define JENT_MEMORY_BLOCKSIZE 32
 #define JENT_MEMORY_ACCESSLOOPS 128
 #define JENT_MEMORY_SIZE (JENT_MEMORY_BLOCKS*JENT_MEMORY_BLOCKSIZE)
-	unsigned char *mem;	/* Memory access location with size of
-				 * memblocks * memblocksize */
-	unsigned int memlocation; /* Pointer to byte in *mem */
-	unsigned int memblocks;	/* Number of memory blocks in *mem */
-	unsigned int memblocksize; /* Size of one memory block in bytes */
-	unsigned int memaccessloops; /* Number of memory accesses per random
-				      * bit generation */
+	unsigned char *mem;		/* Memory access location with size of
+					 * memblocks * memblocksize */
+	unsigned int memlocation; 	/* Pointer to byte in *mem */
+	unsigned int memblocks;		/* Number of memory blocks in *mem */
+	unsigned int memblocksize; 	/* Size of one memory block in bytes */
+	unsigned int memaccessloops;	/* Number of memory accesses per random
+					 * 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 */
-#define JENT_DISABLE_STIR (1<<0) /* Disable stirring the entropy pool */
-#define JENT_DISABLE_UNBIAS (1<<1) /* Disable the Von-Neuman Unbiaser */
+#define JENT_DISABLE_STIR (1<<0) 	/* UNUSED */
+#define JENT_DISABLE_UNBIAS (1<<1) 	/* UNUSED */
 #define JENT_DISABLE_MEMORY_ACCESS (1<<2) /* Disable memory access for more
 					     entropy, saves MEMORY_SIZE RAM for
 					     entropy collector */
@@ -137,6 +150,8 @@ unsigned int jent_version(void);
 #define EMINVARVAR	6 /* Timer variations of variations is too small */
 #define EPROGERR	7 /* Programming error */
 #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 -- */
author	Mounir IDRASSI <mounir.idrassi@idrix.fr>	2019-10-30 12:18:20 +0100
committer	Mounir IDRASSI <mounir.idrassi@idrix.fr>	2019-10-30 22:05:25 +0100
commit	6252d96b0de2001b29596715c8f3345cc93324f7 (patch)
tree	a6829ea7bb3d169d97b82a50697db3b749c0d579 /src
parent	3565cb1afe4f917422853e42d7dbe05526ab750b (diff)
download	VeraCrypt-6252d96b0de2001b29596715c8f3345cc93324f7.tar.gz VeraCrypt-6252d96b0de2001b29596715c8f3345cc93324f7.zip