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Add new tests for the extra testrand functions

master
Pieter Wuille 7 years ago
parent
commit
49b374985d
  1. 76
      src/tests.c

76
src/tests.c

@ -284,6 +284,78 @@ void run_rfc6979_hmac_sha256_tests(void) { @@ -284,6 +284,78 @@ void run_rfc6979_hmac_sha256_tests(void) {
secp256k1_rfc6979_hmac_sha256_finalize(&rng);
}
/***** RANDOM TESTS *****/
void test_rand_bits(int rand32, int bits) {
/* (1-1/2^B)^rounds[B] < 1/10^9, so rounds is the number of iterations to
* get a false negative chance below once in a billion */
static const unsigned int rounds[7] = {1, 30, 73, 156, 322, 653, 1316};
/* We try multiplying the results with various odd numbers, which shouldn't
* influence the uniform distribution modulo a power of 2. */
static const uint32_t mults[6] = {1, 3, 21, 289, 0x9999, 0x80402011};
/* We only select up to 6 bits from the output to analyse */
unsigned int usebits = bits > 6 ? 6 : bits;
unsigned int maxshift = bits - usebits;
/* For each of the maxshift+1 usebits-bit sequences inside a bits-bit
number, track all observed outcomes, one per bit in a uint64_t. */
uint64_t x[6][27] = {{0}};
unsigned int i, shift, m;
/* Multiply the output of all rand calls with the odd number m, which
should not change the uniformity of its distribution. */
for (i = 0; i < rounds[usebits]; i++) {
uint32_t r = (rand32 ? secp256k1_rand32() : secp256k1_rand_bits(bits));
CHECK((((uint64_t)r) >> bits) == 0);
for (m = 0; m < sizeof(mults) / sizeof(mults[0]); m++) {
uint32_t rm = r * mults[m];
for (shift = 0; shift <= maxshift; shift++) {
x[m][shift] |= (((uint64_t)1) << ((rm >> shift) & ((1 << usebits) - 1)));
}
}
}
for (m = 0; m < sizeof(mults) / sizeof(mults[0]); m++) {
for (shift = 0; shift <= maxshift; shift++) {
/* Test that the lower usebits bits of x[shift] are 1 */
CHECK(((~x[m][shift]) << (64 - (1 << usebits))) == 0);
}
}
}
/* Subrange must be a whole divisor of range, and at most 64 */
void test_rand_int(uint32_t range, uint32_t subrange) {
/* (1-1/subrange)^rounds < 1/10^9 */
int rounds = (subrange * 2073) / 100;
int i;
uint64_t x = 0;
CHECK((range % subrange) == 0);
for (i = 0; i < rounds; i++) {
uint32_t r = secp256k1_rand_int(range);
CHECK(r < range);
r = r % subrange;
x |= (((uint64_t)1) << r);
}
/* Test that the lower subrange bits of x are 1. */
CHECK(((~x) << (64 - subrange)) == 0);
}
void run_rand_bits(void) {
size_t b;
test_rand_bits(1, 32);
for (b = 1; b <= 32; b++) {
test_rand_bits(0, b);
}
}
void run_rand_int(void) {
static const uint32_t ms[] = {1, 3, 17, 1000, 13771, 999999, 33554432};
static const uint32_t ss[] = {1, 3, 6, 9, 13, 31, 64};
unsigned int m, s;
for (m = 0; m < sizeof(ms) / sizeof(ms[0]); m++) {
for (s = 0; s < sizeof(ss) / sizeof(ss[0]); s++) {
test_rand_int(ms[m] * ss[s], ss[s]);
}
}
}
/***** NUM TESTS *****/
#ifndef USE_NUM_NONE
@ -2686,6 +2758,10 @@ int main(int argc, char **argv) { @@ -2686,6 +2758,10 @@ int main(int argc, char **argv) {
secp256k1_rand256(run32);
CHECK(secp256k1_context_randomize(ctx, (secp256k1_rand32() & 1) ? run32 : NULL));
}
run_rand_bits();
run_rand_int();
run_sha256_tests();
run_hmac_sha256_tests();
run_rfc6979_hmac_sha256_tests();

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