From 677ef26708ee75bcaee0bdf7ff2ba9273bf5c298 Mon Sep 17 00:00:00 2001 From: Mitya Selivanov Date: Fri, 23 Dec 2022 11:44:02 +0100 Subject: More assertions --- source/kit/bigint.h | 32 ++++++++++++++++--------------- source/kit/mersenne_twister_64.c | 41 +++++++++++++++++++++------------------- source/kit/mersenne_twister_64.h | 10 +++++----- source/kit/secure_random.c | 33 ++++++++++++++++++-------------- 4 files changed, 63 insertions(+), 53 deletions(-) diff --git a/source/kit/bigint.h b/source/kit/bigint.h index f8e76db..7a00cba 100644 --- a/source/kit/bigint.h +++ b/source/kit/bigint.h @@ -341,35 +341,35 @@ typedef struct { */ static kit_bi_division_t kit_bi_udiv(kit_bigint_t const x, kit_bigint_t y) { - kit_bi_division_t result; - memset(&result, 0, sizeof result); + kit_bi_division_t z; + memset(&z, 0, sizeof z); ptrdiff_t const y_bits = kit_bi_significant_bit_count(y); if (y_bits == 0) { - result.undefined = 1; - return result; + z.undefined = 1; + return z; } ptrdiff_t const x_bits = kit_bi_significant_bit_count(x); ptrdiff_t shift = x_bits - y_bits; - result.remainder = x; - result.quotient = kit_bi_uint32(0); + z.remainder = x; + z.quotient = kit_bi_uint32(0); y = kit_bi_shl_uint(y, (uint32_t) shift); while (shift >= 0) { - if (kit_bi_compare(result.remainder, y) >= 0) { - result.remainder = kit_bi_sub(result.remainder, y); - result.quotient.v[shift / 32] |= (1u << (shift % 32)); + if (kit_bi_compare(z.remainder, y) >= 0) { + z.remainder = kit_bi_sub(z.remainder, y); + z.quotient.v[shift / 32] |= (1u << (shift % 32)); } y = kit_bi_shr_uint(y, 1); shift--; } - return result; + return z; } /* Signed division. @@ -382,14 +382,12 @@ static kit_bi_division_t kit_bi_div(kit_bigint_t const x, int const x_neg = kit_bi_is_neg(x); int const y_neg = kit_bi_is_neg(y); - if (!x_neg && !y_neg) - return kit_bi_udiv(x, y); - if (x_neg && y_neg) - return kit_bi_udiv(kit_bi_neg(x), kit_bi_neg(y)); - kit_bigint_t const x_abs = x_neg ? kit_bi_neg(x) : x; kit_bigint_t const y_abs = y_neg ? kit_bi_neg(y) : y; + if (x_neg == y_neg) + return kit_bi_udiv(x_abs, y_abs); + kit_bi_division_t z = kit_bi_udiv(x_abs, y_abs); if (!kit_bi_is_zero(z.remainder) && !y_neg) @@ -402,6 +400,8 @@ static kit_bi_division_t kit_bi_div(kit_bigint_t const x, static void kit_bi_serialize(kit_bigint_t const in, uint8_t *const out) { + assert(out != NULL); + for (ptrdiff_t i = 0; i < KIT_BIGINT_SIZE / 4; i++) { out[i * 4] = (uint8_t) (in.v[i] & 0xff); out[i * 4 + 1] = (uint8_t) ((in.v[i] >> 8) & 0xff); @@ -411,6 +411,8 @@ static void kit_bi_serialize(kit_bigint_t const in, } static kit_bigint_t kit_bi_deserialize(uint8_t const *const in) { + assert(in != NULL); + kit_bigint_t out; memset(&out, 0, sizeof out); diff --git a/source/kit/mersenne_twister_64.c b/source/kit/mersenne_twister_64.c index 0570a1f..926a886 100644 --- a/source/kit/mersenne_twister_64.c +++ b/source/kit/mersenne_twister_64.c @@ -23,33 +23,36 @@ void kit_mt64_init(kit_mt64_state_t *const state, kit_mt64_init_array(state, 1, &seed); } -uint64_t kit_mt64_generate(kit_mt64_state_t *const state) { +void kit_mt64_rotate(kit_mt64_state_t *const state) { static uint64_t const mag01[2] = { 0ull, MATRIX_A }; - int i; uint64_t x; + int i; - if (state->index >= KIT_MT64_N) { - for (i = 0; i < KIT_MT64_N - MM; i++) { - x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); - state->mt[i] = state->mt[i + MM] ^ (x >> 1u) ^ - mag01[(int) (x & 1ull)]; - } + for (i = 0; i < KIT_MT64_N - MM; i++) { + x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); + state->mt[i] = state->mt[i + MM] ^ (x >> 1u) ^ + mag01[(int) (x & 1ull)]; + } - for (; i < KIT_MT64_N - 1; i++) { - x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); - state->mt[i] = state->mt[i + (MM - KIT_MT64_N)] ^ (x >> 1u) ^ - mag01[(int) (x & 1ull)]; - } + for (; i < KIT_MT64_N - 1; i++) { + x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); + state->mt[i] = state->mt[i + (MM - KIT_MT64_N)] ^ (x >> 1u) ^ + mag01[(int) (x & 1ull)]; + } - x = (state->mt[KIT_MT64_N - 1] & UM) | (state->mt[0] & LM); - state->mt[KIT_MT64_N - 1] = state->mt[MM - 1] ^ (x >> 1u) ^ - mag01[(int) (x & 1ull)]; + x = (state->mt[KIT_MT64_N - 1] & UM) | (state->mt[0] & LM); + state->mt[KIT_MT64_N - 1] = state->mt[MM - 1] ^ (x >> 1u) ^ + mag01[(int) (x & 1ull)]; - state->index = 0; - } + state->index = 0; +} + +uint64_t kit_mt64_generate(kit_mt64_state_t *const state) { + if (state->index >= KIT_MT64_N) + kit_mt64_rotate(state); - x = state->mt[state->index++]; + uint64_t x = state->mt[state->index++]; x ^= (x >> 29u) & 0x5555555555555555ull; x ^= (x << 17u) & 0x71d67fffeda60000ull; diff --git a/source/kit/mersenne_twister_64.h b/source/kit/mersenne_twister_64.h index 67a4d22..cc1f3d7 100644 --- a/source/kit/mersenne_twister_64.h +++ b/source/kit/mersenne_twister_64.h @@ -17,17 +17,17 @@ typedef struct { uint64_t index; } kit_mt64_state_t; -void kit_mt64_init_array(kit_mt64_state_t *state, ptrdiff_t size, - uint64_t const *seed); - -void kit_mt64_init(kit_mt64_state_t *state, uint64_t seed); - +void kit_mt64_init_array(kit_mt64_state_t *state, ptrdiff_t size, + uint64_t const *seed); +void kit_mt64_init(kit_mt64_state_t *state, uint64_t seed); +void kit_mt64_rotate(kit_mt64_state_t *state); uint64_t kit_mt64_generate(kit_mt64_state_t *state); #ifndef KIT_DISABLE_SHORT_NAMES # define mt64_state_t kit_mt64_state_t # define mt64_init_array kit_mt64_init_array # define mt64_init kit_mt64_init +# define mt64_rotate kit_mt64_rotate # define mt64_generate kit_mt64_generate # define mt64_seed kit_mt64_seed #endif diff --git a/source/kit/secure_random.c b/source/kit/secure_random.c index 013fd52..65b567c 100644 --- a/source/kit/secure_random.c +++ b/source/kit/secure_random.c @@ -60,23 +60,21 @@ static void secure_random_fallback(ptrdiff_t const size, kit_mt64_state_t state; if (time_sec == 0 && time_nsec == 0) { - uint64_t seed[4] = { n, get_available_memory(), - (uint64_t) t.tv_sec, (uint64_t) t.tv_nsec }; + uint64_t const seed[] = { n, get_available_memory(), + (uint64_t) t.tv_sec, + (uint64_t) t.tv_nsec }; kit_mt64_init_array(&state, sizeof seed / sizeof *seed, seed); } else { - uint64_t seed[6] = { n, - get_available_memory(), - (uint64_t) t.tv_sec, - (uint64_t) t.tv_nsec, - (uint64_t) t.tv_sec - time_sec, - (uint64_t) t.tv_nsec - time_nsec }; + uint64_t const seed[] = { n, + get_available_memory(), + (uint64_t) t.tv_sec, + (uint64_t) t.tv_nsec, + (uint64_t) t.tv_sec - time_sec, + (uint64_t) t.tv_nsec - time_nsec }; kit_mt64_init_array(&state, sizeof seed / sizeof *seed, seed); } - /* Bootstrap the generator. - */ - for (ptrdiff_t i = 0; i < KIT_MT64_N; i++) - kit_mt64_generate(&state); + kit_mt64_rotate(&state); n = kit_mt64_generate(&state); time_sec = (uint64_t) t.tv_sec; @@ -92,20 +90,27 @@ static void secure_random_fallback(ptrdiff_t const size, } void kit_secure_random(ptrdiff_t const size, void *const data) { - if (size <= 0) + assert(size > 0); + assert(data != NULL); + + if (size <= 0 || data == NULL) return; #if defined(_WIN32) && !defined(__CYGWIN__) secure_random_fallback(size, data); #else FILE *f = fopen("/dev/urandom", "rb"); + assert(f != NULL); if (f == NULL) { secure_random_fallback(size, data); return; } - if (fread(data, 1, size, f) != size) { + size_t const n = fread(data, 1, size, f); + assert(n == size); + + if (n != size) { secure_random_fallback(size, data); fclose(f); return; -- cgit v1.2.3