/* * Non-physical true random number generator based on timing jitter. * * Copyright Stephan Mueller , 2014 - 2019 * * 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 prev_time; /* SENSITIVE Previous time stamp */ #define DATA_SIZE_BITS ((sizeof(uint64_t)) * 8) 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 */ /* 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) /* 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 */ /* -- 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. */ #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 -- */ #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 */