+ <ClCompile Include="jitterentropy-base.c">

+ <Optimization Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Disabled</Optimization>

+ <Optimization Condition="'$(Configuration)|$(Platform)'=='Release|x64'">Disabled</Optimization>

+ </ClCompile>

+ <ClInclude Include="jitterentropy-base-user.h" />

+ <ClInclude Include="jitterentropy.h" />

+ <ClCompile Include="jitterentropy-base.c">

+ <Filter>Source Files</Filter>

+ </ClCompile>

+ <ClInclude Include="jitterentropy.h">

+ <Filter>Header Files</Filter>

+ </ClInclude>

+ <ClInclude Include="jitterentropy-base-user.h">

+ <Filter>Header Files</Filter>

+ </ClInclude>

+#include "misc.h"

+ jitterentropy-base.c \

+#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64

+#if defined(TC_WINDOWS_DRIVER) || defined (_UEFI)

+#if defined(__cplusplus)

+extern "C" {

+#endif

+extern unsigned __int64 __rdtsc();

+#if defined(__cplusplus)

+}

+#endif

+#else

+#include <intrin.h>

+#ifdef _MSC_VER

+#pragma intrinsic(__rdtsc)

+#endif

+#endif

+#endif

+

+/*

+ * Non-physical true random number generator based on timing jitter.

+ *

+ * Copyright Stephan Mueller <smueller@chronox.de>, 2013

+ *

+ * License

+ * =======

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions

+ * are met:

+ * 1. Redistributions of source code must retain the above copyright

+ * notice, and the entire permission notice in its entirety,

+ * including the disclaimer of warranties.

+ * 2. Redistributions in binary form must reproduce the above copyright

+ * notice, this list of conditions and the following disclaimer in the

+ * documentation and/or other materials provided with the distribution.

+ * 3. The name of the author may not be used to endorse or promote

+ * products derived from this software without specific prior

+ * written permission.

+ *

+ * ALTERNATIVELY, this product may be distributed under the terms of

+ * the GNU General Public License, in which case the provisions of the GPL are

+ * required INSTEAD OF the above restrictions. (This clause is

+ * necessary due to a potential bad interaction between the GPL and

+ * the restrictions contained in a BSD-style copyright.)

+ *

+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED

+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF

+ * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE

+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT

+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

+ * 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

+ * DAMAGE.

+ */

+

+/* Adapted for VeraCrypt */

+

+#pragma once

+

+#include "Common/Tcdefs.h"

+#include "misc.h"

+#include "cpu.h"

+#include <stdlib.h>

+#include <string.h>

+

+typedef uint64 __u64;

+

+#ifdef _MSC_VER

+

+typedef uint64 uint64_t;

+typedef int64 int64_t;

+

+#ifndef _UEFI

+#define CONFIG_CRYPTO_CPU_JITTERENTROPY_SECURE_MEMORY

+#endif

+

+#ifndef _UEFI

+typedef SSIZE_T ssize_t;

+#else

+#if CRYPTOPP_BOOL_X64

+typedef int64 ssize_t;

+#else

+typedef int32 ssize_t;

+#endif

+#endif

+

+static VC_INLINE void jent_get_nstime(__u64 *out)

+{

+ *out = __rdtsc();;

+}

+

+#else

+

+/* taken from Linux kernel */

+#if CRYPTOPP_BOOL_X64

+#define DECLARE_ARGS(val, low, high) unsigned low, high

+#define EAX_EDX_VAL(val, low, high) ((low) | ((__u64)(high) << 32))

+#define EAX_EDX_RET(val, low, high) "=a" (low), "=d" (high)

+#else

+#define DECLARE_ARGS(val, low, high) unsigned long long val

+#define EAX_EDX_VAL(val, low, high) (val)

+#define EAX_EDX_RET(val, low, high) "=A" (val)

+#endif

+

+static VC_INLINE void jent_get_nstime(__u64 *out)

+{

+ DECLARE_ARGS(val, low, high);

+ asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));

+ *out = EAX_EDX_VAL(val, low, high);

+}

+

+#endif

+

+static VC_INLINE void *jent_zalloc(size_t len)

+{

+ void *tmp = NULL;

+ tmp = TCalloc(len);

+ if(NULL != tmp)

+ {

+ memset(tmp, 0, len);

+#if defined(_WIN32) && !defined(TC_WINDOWS_DRIVER) && !defined(_UEFI)

+ VirtualLock (tmp, len);

+#endif

+ }

+ return tmp;

+}

+

+static VC_INLINE void jent_zfree(void *ptr, unsigned int len)

+{

+ if (len % 8)

+ burn(ptr, len);

+ else

+ FAST_ERASE64(ptr, len);

+#if defined(_WIN32) && !defined(TC_WINDOWS_DRIVER) && !defined(_UEFI)

+ VirtualUnlock (ptr, len);

+#endif

+ TCfree(ptr);

+}

+

+static VC_INLINE int jent_fips_enabled(void)

+{

+ return 0;

+}

+

+/* --- helpers needed in user space -- */

+

+#define rol64(x,n) rotl64(x,n)

+

+

+

+/*

+ * Non-physical true random number generator based on timing jitter.

+ *

+ * Copyright Stephan Mueller <smueller@chronox.de>, 2014 - 2018

+ *

+ * Design

+ * ======

+ *

+ * See documentation in doc/ folder.

+ *

+ * Interface

+ * =========

+ *

+ * See documentation in doc/ folder.

+ *

+ * License

+ * =======

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions

+ * are met:

+ * 1. Redistributions of source code must retain the above copyright

+ * notice, and the entire permission notice in its entirety,

+ * including the disclaimer of warranties.

+ * 2. Redistributions in binary form must reproduce the above copyright

+ * notice, this list of conditions and the following disclaimer in the

+ * documentation and/or other materials provided with the distribution.

+ * 3. The name of the author may not be used to endorse or promote

+ * products derived from this software without specific prior

+ * written permission.

+ *

+ * ALTERNATIVELY, this product may be distributed under the terms of

+ * the GNU General Public License, in which case the provisions of the GPL2 are

+ * required INSTEAD OF the above restrictions. (This clause is

+ * necessary due to a potential bad interaction between the GPL and

+ * the restrictions contained in a BSD-style copyright.)

+ *

+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED

+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF

+ * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE

+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT

+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

+ * 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

+ * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH

+ * DAMAGE.

+ */

+

+/* Adapted for VeraCrypt */

+

+#undef _FORTIFY_SOURCE

+

+#ifdef _MSC_VER

+#pragma optimize( "", off )

+#pragma warning(disable:4242 4244 4334) /* disable warnings on the original code */

+#else

+#pragma GCC optimize ("O0")

+#endif

+

+#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

+#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

+ * enhancements only, consumer can be left unchanged if

+ * enhancements are not considered */

+#define PATCHLEVEL 2 /* API / ABI compatible, no functional changes, no

+ * enhancements, bug fixes only */

+

+/**

+ * jent_version() - Return machine-usable version number of jent library

+ *

+ * The function returns a version number that is monotonic increasing

+ * for newer versions. The version numbers are multiples of 100. For example,

+ * version 1.2.3 is converted to 1020300 -- the last two digits are reserved

+ * for future use.

+ *

+ * 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

+ */

+JENT_PRIVATE_STATIC

+unsigned int jent_version(void)

+{

+ unsigned int version = 0;

+

+ version = MAJVERSION * 1000000;

+ version += MINVERSION * 10000;

+ version += PATCHLEVEL * 100;

+

+ return version;

+}

+

+/**

+ * 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

+ *

+ * @return Newly calculated loop counter

+ */

+static uint64_t jent_loop_shuffle(struct rand_data *ec,

+ unsigned int bits, unsigned int min)

+{

+ uint64_t time = 0;

+ uint64_t shuffle = 0;

+ unsigned int i = 0;

+ unsigned int mask = (1<<bits) - 1;

+

+ jent_get_nstime(&time);

+ /*

+ * Mix the current state of the random number into the shuffle

+ * calculation to balance that shuffle a bit more.

+ */

+ if (ec)

+ time ^= ec->data;

+ /*

+ * We fold the time value as much as possible to ensure that as many

+ * bits of the time stamp are included as possible.

+ */

+ for (i = 0; ((DATA_SIZE_BITS + bits - 1) / bits) > i; i++) {

+ shuffle ^= time & mask;

+ time = time >> bits;

+ }

+

+ /*

+ * We add a lower boundary value to ensure we have a minimum

+ * RNG loop count.

+ */

+ return (shuffle + (1<<min));

+}

+

+/***************************************************************************

+ * Noise sources

+ ***************************************************************************/

+

+/**

+ * CPU Jitter noise source -- this is the noise source based on the CPU

+ * execution time jitter

+ *

+ * This function injects the individual bits of the time value into the

+ * entropy pool using an LFSR.

+ *

+ * 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

+ * 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

+ *

+ * 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)

+{

+ 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 =

+ jent_loop_shuffle(ec, MAX_FOLD_LOOP_BIT, MIN_FOLD_LOOP_BIT);

+

+ /*

+ * testing purposes -- allow test app to set the counter, not

+ * needed during runtime

+ */

+ if (loop_cnt)

+ fold_loop_cnt = loop_cnt;

+ for (j = 0; j < fold_loop_cnt; j++) {

+ new = ec->data;

+ for (i = 1; (DATA_SIZE_BITS) >= i; i++) {

+ uint64_t tmp = time << (DATA_SIZE_BITS - i);

+

+ tmp = tmp >> (DATA_SIZE_BITS - 1);

+

+ /*

+ * Fibonacci LSFR with polynomial of

+ * x^64 + x^61 + x^56 + x^31 + x^28 + x^23 + 1 which is

+ * primitive according to

+ * http://poincare.matf.bg.ac.rs/~ezivkovm/publications/primpol1.pdf

+ * (the shift values are the polynomial values minus one

+ * due to counting bits from 0 to 63). As the current

+ * position is always the LSB, the polynomial only needs

+ * to shift data in from the left without wrap.

+ */

+ tmp ^= ((new >> 63) & 1);

+ tmp ^= ((new >> 60) & 1);

+ tmp ^= ((new >> 55) & 1);

+ tmp ^= ((new >> 30) & 1);

+ tmp ^= ((new >> 27) & 1);

+ tmp ^= ((new >> 22) & 1);

+ new <<= 1;

+ new ^= tmp;

+ }

+ }

+ ec->data = new;

+

+ return fold_loop_cnt;

+}

+

+/**

+ * Memory Access noise source -- this is a noise source based on variations in

+ * memory access times

+ *

+ * This function performs memory accesses which will add to the timing

+ * variations due to an unknown amount of CPU wait states that need to be

+ * added when accessing memory. The memory size should be larger than the L1

+ * caches as outlined in the documentation and the associated testing.

+ *

+ * The L1 cache has a very high bandwidth, albeit its access rate is usually

+ * slower than accessing CPU registers. Therefore, L1 accesses only add minimal

+ * variations as the CPU has hardly to wait. Starting with L2, significant

+ * variations are added because L2 typically does not belong to the CPU any more

+ * and therefore a wider range of CPU wait states is necessary for accesses.

+ * L3 and real memory accesses have even a wider range of wait states. However,

+ * 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

+ */

+static unsigned int jent_memaccess(struct rand_data *ec, uint64_t loop_cnt)

+{

+ unsigned int wrap = 0;

+ uint64_t i = 0;

+#define MAX_ACC_LOOP_BIT 7

+#define MIN_ACC_LOOP_BIT 0

+ uint64_t acc_loop_cnt =

+ jent_loop_shuffle(ec, MAX_ACC_LOOP_BIT, MIN_ACC_LOOP_BIT);

+

+ if (NULL == ec || NULL == ec->mem)

+ return 0;

+ wrap = ec->memblocksize * ec->memblocks;

+

+ /*

+ * testing purposes -- allow test app to set the counter, not

+ * needed during runtime

+ */

+ if (loop_cnt)

+ acc_loop_cnt = loop_cnt;

+

+ for (i = 0; i < (ec->memaccessloops + acc_loop_cnt); i++) {

+ unsigned char *tmpval = ec->mem + ec->memlocation;

+ /*

+ * memory access: just add 1 to one byte,

+ * wrap at 255 -- memory access implies read

+ * from and write to memory location

+ */

+ *tmpval = (*tmpval + 1) & 0xff;

+ /*

+ * Addition of memblocksize - 1 to pointer

+ * with wrap around logic to ensure that every

+ * memory location is hit evenly

+ */

+ 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

+ * entropy pool.

+ *

+ * WARNING: ensure that ->prev_time is primed before using the output

+ * of this function! This can be done by calling this function

+ * and not using its result.

+ *

+ * Input:

+ * @entropy_collector Reference to entropy collector

+ *

+ * @return: result of stuck test

+ */

+static int jent_measure_jitter(struct rand_data *ec)

+{

+ uint64_t time = 0;

+ uint64_t current_delta = 0;

+

+ /* Invoke one noise source before time measurement to add variations */

+ jent_memaccess(ec, 0);

+

+ /*

+ * Get time stamp and calculate time delta to previous

+ * invocation to measure the timing variations

+ */

+ jent_get_nstime(&time);

+ current_delta = time - ec->prev_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. */

+ return jent_stuck(ec, current_delta);

+}

+

+/**

+ * Generator of one 64 bit random number

+ * Function fills rand_data->data

+ *

+ * Input:

+ * @ec Reference to entropy collector

+ */

+static void jent_gen_entropy(struct rand_data *ec)

+{

+ unsigned int k = 0;

+

+ /* priming of the ->prev_time value */

+ jent_measure_jitter(ec);

+

+ while (1) {

+ /* If a stuck measurement is received, repeat measurement */

+ if (jent_measure_jitter(ec))

+ continue;

+

+ /*

+ * We multiply the loop value with ->osr to obtain the

+ * oversampling rate requested by the caller

+ */

+ if (++k >= (DATA_SIZE_BITS * ec->osr))

+ break;

+ }

+}

+

+/**

+ * 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

+ * as many bytes as requested by the caller. The entropy gathering logic

+ * creates 64 bit per invocation.

+ *

+ * 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

+ *

+ * @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

+ */

+JENT_PRIVATE_STATIC

+ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len)

+{

+ char *p = data;

+ size_t orig_len = len;

+

+ if (NULL == ec)

+ return -1;

+

+ while (0 < len) {

+ size_t tocopy;

+

+ jent_gen_entropy(ec);

+ if (jent_fips_test(ec))

+ return -2;

+

+ if ((DATA_SIZE_BITS / 8) < len)

+ tocopy = (DATA_SIZE_BITS / 8);

+ else

+ tocopy = len;

+ memcpy(p, &ec->data, tocopy);

+

+ len -= tocopy;

+ p += tocopy;

+ }

+

+ /*

+ * To be on the safe side, we generate one more round of entropy

+ * which we do not give out to the caller. That round shall ensure

+ * that in case the calling application crashes, memory dumps, pages

+ * out, or due to the CPU Jitter RNG lingering in memory for long

+ * time without being moved and an attacker cracks the application,

+ * all he reads in the entropy pool is a value that is NEVER EVER

+ * being used for anything. Thus, he does NOT see the previous value

+ * that was returned to the caller for cryptographic purposes.

+ */

+ /*

+ * If we use secured memory, do not use that precaution as the secure

+ * memory protects the entropy pool. Moreover, note that using this

+ * call reduces the speed of the RNG by up to half

+ */

+#ifndef CONFIG_CRYPTO_CPU_JITTERENTROPY_SECURE_MEMORY

+ jent_gen_entropy(ec);

+#endif

+ return orig_len;

+}

+

+/***************************************************************************

+ * Initialization logic

+ ***************************************************************************/

+

+JENT_PRIVATE_STATIC

+struct rand_data *jent_entropy_collector_alloc(unsigned int osr,

+ unsigned int flags)

+{

+ struct rand_data *entropy_collector;

+

+ entropy_collector = jent_zalloc(sizeof(struct rand_data));

+ if (NULL == entropy_collector)

+ return NULL;

+

+ if (!(flags & JENT_DISABLE_MEMORY_ACCESS)) {

+ /* Allocate memory for adding variations based on memory

+ * access

+ */

+ entropy_collector->mem =

+ (unsigned char *)jent_zalloc(JENT_MEMORY_SIZE);

+ if (NULL == entropy_collector->mem) {

+ jent_zfree(entropy_collector, sizeof(struct rand_data));

+ return NULL;

+ }

+ entropy_collector->memblocksize = JENT_MEMORY_BLOCKSIZE;

+ entropy_collector->memblocks = JENT_MEMORY_BLOCKS;

+ entropy_collector->memaccessloops = JENT_MEMORY_ACCESSLOOPS;

+ }

+

+ /* verify and set the oversampling rate */

+ if (0 == 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;

+

+ /* fill the data pad with non-zero values */

+ jent_gen_entropy(entropy_collector);

+

+ return entropy_collector;

+}

+

+JENT_PRIVATE_STATIC

+void jent_entropy_collector_free(struct rand_data *entropy_collector)

+{

+ if (NULL != entropy_collector) {

+ if (NULL != entropy_collector->mem) {

+ jent_zfree(entropy_collector->mem, JENT_MEMORY_SIZE);

+ entropy_collector->mem = NULL;

+ }

+ jent_zfree(entropy_collector, sizeof(struct rand_data));

+ }

+}

+

+JENT_PRIVATE_STATIC

+int jent_entropy_init(void)

+{

+ int i;

+ uint64_t delta_sum = 0;

+ uint64_t old_delta = 0;

+ int time_backwards = 0;

+ int count_mod = 0;

+ int count_stuck = 0;

+ struct rand_data ec;

+

+ memset(&ec, 0, sizeof(ec));

+

+ /* 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

+ * false positives.

+ *

+ * Moreover, only old systems show potentially problematic

+ * jitter entropy that could potentially be caught here. But

+ * the RNG is intended for hardware that is available or widely

+ * used, but not old systems that are long out of favor. Thus,

+ * no statistical tests.

+ */

+

+ /*

+ * We could add a check for system capabilities such as clock_getres or

+ * check for CONFIG_X86_TSC, but it does not make much sense as the

+ * following sanity checks verify that we have a high-resolution

+ * timer.

+ */

+ /*

+ * TESTLOOPCOUNT needs some loops to identify edge systems. 100 is

+ * definitely too little.

+ */

+#define TESTLOOPCOUNT 300

+#define CLEARCACHE 100

+ for (i = 0; (TESTLOOPCOUNT + CLEARCACHE) > i; i++) {

+ uint64_t time = 0;

+ uint64_t time2 = 0;

+ uint64_t delta = 0;

+ unsigned int lowdelta = 0;

+ int stuck;

+

+ /* Invoke core entropy collection logic */

+ jent_get_nstime(&time);

+ ec.prev_time = time;

+ jent_lfsr_time(&ec, time, 0);

+ jent_get_nstime(&time2);

+

+ /* test whether timer works */

+ if (!time || !time2)

+ return ENOTIME;

+ delta = time2 - time;

+ /*

+ * test whether timer is fine grained enough to provide

+ * delta even when called shortly after each other -- this

+ * implies that we also have a high resolution timer

+ */

+ if (!delta)

+ return ECOARSETIME;

+

+ stuck = jent_stuck(&ec, delta);

+

+ /*

+ * up to here we did not modify any variable that will be

+ * evaluated later, but we already performed some work. Thus we

+ * already have had an impact on the caches, branch prediction,

+ * etc. with the goal to clear it to get the worst case

+ * measurements.

+ */

+ if (CLEARCACHE > i)

+ continue;

+

+ if (stuck)

+ count_stuck++;

+

+ /* 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;

+ if (!(lowdelta % 100))

+ count_mod++;

+

+ /*

+ * ensure that we have a varying delta timer which is necessary

+ * for the calculation of entropy -- perform this check

+ * only after the first loop is executed as we need to prime

+ * the old_data value

+ */

+ if (delta > old_delta)

+ delta_sum += (delta - old_delta);

+ else

+ delta_sum += (old_delta - delta);

+ old_delta = delta;

+ }

+

+ /*

+ * we allow up to three times the time running backwards.

+ * CLOCK_REALTIME is affected by adjtime and NTP operations. Thus,

+ * if such an operation just happens to interfere with our test, it

+ * should not fail. The value of 3 should cover the NTP case being

+ * performed during our test run.

+ */

+ if (3 < time_backwards)

+ return ENOMONOTONIC;

+

+ /*

+ * Variations of deltas of time must on average be larger

+ * than 1 to ensure the entropy estimation

+ * implied with 1 is preserved

+ */

+ if ((delta_sum) <= 1)

+ return EMINVARVAR;

+

+ /*

+ * Ensure that we have variations in the time stamp below 10 for at least

+ * 10% of all checks -- on some platforms, the counter increments in

+ * multiples of 100, but not always

+ */

+ if ((TESTLOOPCOUNT/10 * 9) < count_mod)

+ return ECOARSETIME;

+

+ /*

+ * 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)

+ 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 */

+/*

+ * Non-physical true random number generator based on timing jitter.

+ *

+ * Copyright Stephan Mueller <smueller@chronox.de>, 2014

+ *

+ * License

+ * =======

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions

+ * are met:

+ * 1. Redistributions of source code must retain the above copyright

+ * notice, and the entire permission notice in its entirety,

+ * including the disclaimer of warranties.

+ * 2. Redistributions in binary form must reproduce the above copyright

+ * notice, this list of conditions and the following disclaimer in the

+ * documentation and/or other materials provided with the distribution.

+ * 3. The name of the author may not be used to endorse or promote

+ * products derived from this software without specific prior

+ * written permission.

+ *

+ * ALTERNATIVELY, this product may be distributed under the terms of

+ * the GNU General Public License, in which case the provisions of the GPL are

+ * required INSTEAD OF the above restrictions. (This clause is

+ * necessary due to a potential bad interaction between the GPL and

+ * the restrictions contained in a BSD-style copyright.)

+ *

+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED

+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF

+ * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE

+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT

+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

+ * 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

+ * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH

+ * DAMAGE.

+ */

+

+/* Adapted for VeraCrypt */

+

+#ifndef _JITTERENTROPY_H

+#define _JITTERENTROPY_H

+

+#include "jitterentropy-base-user.h"

+

+/* The entropy pool */

+struct rand_data

+{

+ /* all data values that are vital to maintain the security

+ * 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 */

+#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 */

+#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 */

+};

+

+/* 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_MEMORY_ACCESS (1<<2) /* Disable memory access for more

+ entropy, saves MEMORY_SIZE RAM for

+ entropy collector */

+

+/* -- BEGIN Main interface functions -- */

+

+#ifndef JENT_STUCK_INIT_THRES

+/*

+ * Per default, not more than 90% of all measurements during initialization

+ * are allowed to be stuck.

+ *

+ * It is allowed to change this value as required for the intended environment.

+ */

+#define JENT_STUCK_INIT_THRES(x) (x/10 * 9)

+#endif

+

+#ifdef JENT_PRIVATE_COMPILE

+# define JENT_PRIVATE_STATIC static

+#else /* JENT_PRIVATE_COMPILE */

+# define JENT_PRIVATE_STATIC

+#endif

+

+#ifdef __cplusplus

+extern "C" {

+#endif

+

+/* Number of low bits of the time value that we want to consider */

+/* get raw entropy */

+JENT_PRIVATE_STATIC

+ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len);

+/* initialize an instance of the entropy collector */

+JENT_PRIVATE_STATIC

+struct rand_data *jent_entropy_collector_alloc(unsigned int osr,

+ unsigned int flags);

+/* clearing of entropy collector */

+JENT_PRIVATE_STATIC

+void jent_entropy_collector_free(struct rand_data *entropy_collector);

+

+/* initialization of entropy collector */

+JENT_PRIVATE_STATIC

+int jent_entropy_init(void);

+

+/* return version number of core library */

+JENT_PRIVATE_STATIC

+unsigned int jent_version(void);

+

+/* -- END of Main interface functions -- */

+

+/* -- BEGIN error codes for init function -- */

+#define ENOTIME 1 /* Timer service not available */

+#define ECOARSETIME 2 /* Timer too coarse for RNG */

+#define ENOMONOTONIC 3 /* Timer is not monotonic increasing */

+#define EMINVARIATION 4 /* Timer variations too small for RNG */

+#define EVARVAR 5 /* Timer does not produce variations of variations

+ (2nd derivation of time is zero) */

+#define EMINVARVAR 6 /* Timer variations of variations is too small */

+#define EPROGERR 7 /* Programming error */

+#define ESTUCK 8 /* Too many stuck results during init. */

+

+/* -- BEGIN statistical test functions only complied with CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT -- */

+

+#ifdef CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT

+JENT_PRIVATE_STATIC

+uint64_t jent_lfsr_var_stat(struct rand_data *ec, unsigned int min);

+#endif /* CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT */

+

+/* -- END of statistical test function -- */

+

+#ifdef __cplusplus

+}

+#endif

+

+

+#endif /* _JITTERENTROPY_H */