Add scalar_set_b32_seckey which does the same as scalar_set_b32 and also returns whether it's a valid secret key

This commit is contained in:
Jonas Nick 2019-12-17 15:32:00 +00:00
parent 4f27e344c6
commit 9ab2cbe0eb
3 changed files with 36 additions and 0 deletions

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@ -39,6 +39,10 @@ static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, uns
*/
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *bin, int *overflow);
/** Set a scalar from a big endian byte array and returns 1 if it is a valid
* seckey and 0 otherwise. */
static int secp256k1_scalar_set_b32_seckey(secp256k1_scalar *r, const unsigned char *bin);
/** Set a scalar to an unsigned integer. */
static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v);

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@ -55,6 +55,12 @@ static void secp256k1_scalar_order_get_num(secp256k1_num *r) {
}
#endif
static int secp256k1_scalar_set_b32_seckey(secp256k1_scalar *r, const unsigned char *bin) {
int overflow;
secp256k1_scalar_set_b32(r, bin, &overflow);
return (!overflow) & (!secp256k1_scalar_is_zero(r));
}
static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *x) {
#if defined(EXHAUSTIVE_TEST_ORDER)
int i;

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@ -140,6 +140,12 @@ void random_scalar_order(secp256k1_scalar *num) {
} while(1);
}
void random_scalar_order_b32(unsigned char *b32) {
secp256k1_scalar num;
random_scalar_order(&num);
secp256k1_scalar_get_b32(b32, &num);
}
void run_context_tests(int use_prealloc) {
secp256k1_pubkey pubkey;
secp256k1_pubkey zero_pubkey;
@ -1077,11 +1083,31 @@ void scalar_test(void) {
}
void run_scalar_set_b32_seckey_tests(void) {
unsigned char b32[32];
secp256k1_scalar s1;
secp256k1_scalar s2;
/* Usually set_b32 and set_b32_seckey give the same result */
random_scalar_order_b32(b32);
secp256k1_scalar_set_b32(&s1, b32, NULL);
CHECK(secp256k1_scalar_set_b32_seckey(&s2, b32) == 1);
CHECK(secp256k1_scalar_eq(&s1, &s2) == 1);
memset(b32, 0, sizeof(b32));
CHECK(secp256k1_scalar_set_b32_seckey(&s2, b32) == 0);
memset(b32, 0xFF, sizeof(b32));
CHECK(secp256k1_scalar_set_b32_seckey(&s2, b32) == 0);
}
void run_scalar_tests(void) {
int i;
for (i = 0; i < 128 * count; i++) {
scalar_test();
}
for (i = 0; i < count; i++) {
run_scalar_set_b32_seckey_tests();
}
{
/* (-1)+1 should be zero. */