diff options
Diffstat (limited to 'crypto/jitterentropy.c')
| -rw-r--r-- | crypto/jitterentropy.c | 215 |
1 files changed, 37 insertions, 178 deletions
diff --git a/crypto/jitterentropy.c b/crypto/jitterentropy.c index d3c30452edee..acf44b2d2d1d 100644 --- a/crypto/jitterentropy.c +++ b/crypto/jitterentropy.c @@ -1,7 +1,8 @@ /* - * Non-physical true random number generator based on timing jitter. + * Non-physical true random number generator based on timing jitter -- + * Jitter RNG standalone code. * - * Copyright Stephan Mueller <smueller@chronox.de>, 2014 + * Copyright Stephan Mueller <smueller@chronox.de>, 2015 * * Design * ====== @@ -49,13 +50,14 @@ * version 1.1.0 provided at http://www.chronox.de/jent.html */ -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/module.h> -#include <linux/fips.h> -#include <linux/time.h> -#include <linux/crypto.h> -#include <crypto/internal/rng.h> +#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.c." +#endif + +typedef unsigned long long __u64; +typedef long long __s64; +typedef unsigned int __u32; +#define NULL ((void *) 0) /* The entropy pool */ struct rand_data { @@ -93,8 +95,6 @@ struct rand_data { * entropy, saves MEMORY_SIZE RAM for * entropy collector */ -#define DRIVER_NAME "jitterentropy" - /* -- error codes for init function -- */ #define JENT_ENOTIME 1 /* Timer service not available */ #define JENT_ECOARSETIME 2 /* Timer too coarse for RNG */ @@ -110,32 +110,13 @@ struct rand_data { * Helper functions ***************************************************************************/ -static inline void jent_get_nstime(__u64 *out) -{ - struct timespec ts; - __u64 tmp = 0; - - tmp = random_get_entropy(); - - /* - * If random_get_entropy does not return a value (which is possible on, - * for example, MIPS), invoke __getnstimeofday - * hoping that there are timers we can work with. - * - * The list of available timers can be obtained from - * /sys/devices/system/clocksource/clocksource0/available_clocksource - * and are registered with clocksource_register() - */ - if ((0 == tmp) && - (0 == __getnstimeofday(&ts))) { - tmp = ts.tv_sec; - tmp = tmp << 32; - tmp = tmp | ts.tv_nsec; - } - - *out = tmp; -} - +void jent_get_nstime(__u64 *out); +__u64 jent_rol64(__u64 word, unsigned int shift); +void *jent_zalloc(unsigned int len); +void jent_zfree(void *ptr); +int jent_fips_enabled(void); +void jent_panic(char *s); +void jent_memcpy(void *dest, const void *src, unsigned int n); /** * Update of the loop count used for the next round of @@ -184,20 +165,6 @@ static __u64 jent_loop_shuffle(struct rand_data *ec, * Noise sources ***************************************************************************/ -/* - * The disabling of the optimizations is performed as documented and assessed - * thoroughly in http://www.chronox.de/jent.html. However, instead of disabling - * the optimization of the entire C file, only the main functions the jitter is - * measured for are not optimized. These functions include the noise sources as - * well as the main functions triggering the noise sources. As the time - * measurement is done from one invocation of the jitter noise source to the - * next, even the execution jitter of the code invoking the noise sources - * contribute to the overall randomness as well. The behavior of the RNG and the - * statistical characteristics when only the mentioned functions are not - * optimized is almost equal to the a completely non-optimized RNG compilation - * as tested with the test tools provided at the initially mentioned web site. - */ - /** * CPU Jitter noise source -- this is the noise source based on the CPU * execution time jitter @@ -232,8 +199,6 @@ static __u64 jent_loop_shuffle(struct rand_data *ec, * * @return Number of loops the folding operation is performed */ -#pragma GCC push_options -#pragma GCC optimize ("-O0") static __u64 jent_fold_time(struct rand_data *ec, __u64 time, __u64 *folded, __u64 loop_cnt) { @@ -263,7 +228,6 @@ static __u64 jent_fold_time(struct rand_data *ec, __u64 time, *folded = new; return fold_loop_cnt; } -#pragma GCC pop_options /** * Memory Access noise source -- this is a noise source based on variations in @@ -292,8 +256,6 @@ static __u64 jent_fold_time(struct rand_data *ec, __u64 time, * * @return Number of memory access operations */ -#pragma GCC push_options -#pragma GCC optimize ("-O0") static unsigned int jent_memaccess(struct rand_data *ec, __u64 loop_cnt) { unsigned char *tmpval = NULL; @@ -333,7 +295,6 @@ static unsigned int jent_memaccess(struct rand_data *ec, __u64 loop_cnt) } return i; } -#pragma GCC pop_options /*************************************************************************** * Start of entropy processing logic @@ -382,8 +343,6 @@ static void jent_stuck(struct rand_data *ec, __u64 current_delta) * * @return One random bit */ -#pragma GCC push_options -#pragma GCC optimize ("-O0") static __u64 jent_measure_jitter(struct rand_data *ec) { __u64 time = 0; @@ -413,7 +372,6 @@ static __u64 jent_measure_jitter(struct rand_data *ec) return data; } -#pragma GCC pop_options /** * Von Neuman unbias as explained in RFC 4086 section 4.2. As shown in the @@ -502,7 +460,7 @@ static void jent_stir_pool(struct rand_data *entropy_collector) */ if ((entropy_collector->data >> i) & 1) mixer.u64 ^= constant.u64; - mixer.u64 = rol64(mixer.u64, 1); + mixer.u64 = jent_rol64(mixer.u64, 1); } entropy_collector->data ^= mixer.u64; } @@ -514,8 +472,6 @@ static void jent_stir_pool(struct rand_data *entropy_collector) * Input: * @ec Reference to entropy collector */ -#pragma GCC push_options -#pragma GCC optimize ("-O0") static void jent_gen_entropy(struct rand_data *ec) { unsigned int k = 0; @@ -565,7 +521,7 @@ static void jent_gen_entropy(struct rand_data *ec) ec->data ^= ((ec->data >> 30) & 1); ec->data ^= ((ec->data >> 27) & 1); ec->data ^= ((ec->data >> 22) & 1); - ec->data = rol64(ec->data, 1); + ec->data = jent_rol64(ec->data, 1); /* * We multiply the loop value with ->osr to obtain the @@ -577,7 +533,6 @@ static void jent_gen_entropy(struct rand_data *ec) if (ec->stir) jent_stir_pool(ec); } -#pragma GCC pop_options /** * The continuous test required by FIPS 140-2 -- the function automatically @@ -589,7 +544,7 @@ static void jent_gen_entropy(struct rand_data *ec) */ static void jent_fips_test(struct rand_data *ec) { - if (!fips_enabled) + if (!jent_fips_enabled()) return; /* prime the FIPS test */ @@ -599,12 +554,11 @@ static void jent_fips_test(struct rand_data *ec) } if (ec->data == ec->old_data) - panic(DRIVER_NAME ": Duplicate output detected\n"); + jent_panic("jitterentropy: Duplicate output detected\n"); ec->old_data = ec->data; } - /** * Entry function: Obtain entropy for the caller. * @@ -627,15 +581,16 @@ static void jent_fips_test(struct rand_data *ec) * The following error codes can occur: * -1 entropy_collector is NULL */ -static ssize_t jent_read_entropy(struct rand_data *ec, u8 *data, size_t len) +int jent_read_entropy(struct rand_data *ec, unsigned char *data, + unsigned int len) { - u8 *p = data; + unsigned char *p = data; if (!ec) - return -EINVAL; + return -1; while (0 < len) { - size_t tocopy; + unsigned int tocopy; jent_gen_entropy(ec); jent_fips_test(ec); @@ -643,7 +598,7 @@ static ssize_t jent_read_entropy(struct rand_data *ec, u8 *data, size_t len) tocopy = (DATA_SIZE_BITS / 8); else tocopy = len; - memcpy(p, &ec->data, tocopy); + jent_memcpy(p, &ec->data, tocopy); len -= tocopy; p += tocopy; @@ -656,12 +611,12 @@ static ssize_t jent_read_entropy(struct rand_data *ec, u8 *data, size_t len) * Initialization logic ***************************************************************************/ -static struct rand_data *jent_entropy_collector_alloc(unsigned int osr, - unsigned int flags) +struct rand_data *jent_entropy_collector_alloc(unsigned int osr, + unsigned int flags) { struct rand_data *entropy_collector; - entropy_collector = kzalloc(sizeof(struct rand_data), GFP_KERNEL); + entropy_collector = jent_zalloc(sizeof(struct rand_data)); if (!entropy_collector) return NULL; @@ -669,9 +624,9 @@ static struct rand_data *jent_entropy_collector_alloc(unsigned int osr, /* Allocate memory for adding variations based on memory * access */ - entropy_collector->mem = kzalloc(JENT_MEMORY_SIZE, GFP_KERNEL); + entropy_collector->mem = jent_zalloc(JENT_MEMORY_SIZE); if (!entropy_collector->mem) { - kfree(entropy_collector); + jent_zfree(entropy_collector); return NULL; } entropy_collector->memblocksize = JENT_MEMORY_BLOCKSIZE; @@ -696,17 +651,15 @@ static struct rand_data *jent_entropy_collector_alloc(unsigned int osr, return entropy_collector; } -static void jent_entropy_collector_free(struct rand_data *entropy_collector) +void jent_entropy_collector_free(struct rand_data *entropy_collector) { - if (entropy_collector->mem) - kzfree(entropy_collector->mem); + jent_zfree(entropy_collector->mem); entropy_collector->mem = NULL; - if (entropy_collector) - kzfree(entropy_collector); + jent_zfree(entropy_collector); entropy_collector = NULL; } -static int jent_entropy_init(void) +int jent_entropy_init(void) { int i; __u64 delta_sum = 0; @@ -832,97 +785,3 @@ static int jent_entropy_init(void) return 0; } - -/*************************************************************************** - * Kernel crypto API interface - ***************************************************************************/ - -struct jitterentropy { - spinlock_t jent_lock; - struct rand_data *entropy_collector; -}; - -static int jent_kcapi_init(struct crypto_tfm *tfm) -{ - struct jitterentropy *rng = crypto_tfm_ctx(tfm); - int ret = 0; - - rng->entropy_collector = jent_entropy_collector_alloc(1, 0); - if (!rng->entropy_collector) - ret = -ENOMEM; - - spin_lock_init(&rng->jent_lock); - return ret; -} - -static void jent_kcapi_cleanup(struct crypto_tfm *tfm) -{ - struct jitterentropy *rng = crypto_tfm_ctx(tfm); - - spin_lock(&rng->jent_lock); - if (rng->entropy_collector) - jent_entropy_collector_free(rng->entropy_collector); - rng->entropy_collector = NULL; - spin_unlock(&rng->jent_lock); -} - -static int jent_kcapi_random(struct crypto_rng *tfm, - const u8 *src, unsigned int slen, - u8 *rdata, unsigned int dlen) -{ - struct jitterentropy *rng = crypto_rng_ctx(tfm); - int ret = 0; - - spin_lock(&rng->jent_lock); - ret = jent_read_entropy(rng->entropy_collector, rdata, dlen); - spin_unlock(&rng->jent_lock); - - return ret; -} - -static int jent_kcapi_reset(struct crypto_rng *tfm, - const u8 *seed, unsigned int slen) -{ - return 0; -} - -static struct rng_alg jent_alg = { - .generate = jent_kcapi_random, - .seed = jent_kcapi_reset, - .seedsize = 0, - .base = { - .cra_name = "jitterentropy_rng", - .cra_driver_name = "jitterentropy_rng", - .cra_priority = 100, - .cra_ctxsize = sizeof(struct jitterentropy), - .cra_module = THIS_MODULE, - .cra_init = jent_kcapi_init, - .cra_exit = jent_kcapi_cleanup, - - } -}; - -static int __init jent_mod_init(void) -{ - int ret = 0; - - ret = jent_entropy_init(); - if (ret) { - pr_info(DRIVER_NAME ": Initialization failed with host not compliant with requirements: %d\n", ret); - return -EFAULT; - } - return crypto_register_rng(&jent_alg); -} - -static void __exit jent_mod_exit(void) -{ - crypto_unregister_rng(&jent_alg); -} - -module_init(jent_mod_init); -module_exit(jent_mod_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); -MODULE_DESCRIPTION("Non-physical True Random Number Generator based on CPU Jitter"); -MODULE_ALIAS_CRYPTO("jitterentropy_rng"); 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