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Add verification to 32bit field

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- implement _fe_verify for 10x26
- fe is normalized after _fe_clear
- a few corresponding changes in 64bit field
This commit is contained in:
Peter Dettman
2014-11-01 16:58:42 +07:00
parent 27aded3ccb
commit 7d681ac636
2 changed files with 79 additions and 18 deletions
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11
src/field_5x52_impl.h
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@@ -43,8 +43,9 @@ void static secp256k1_fe_verify(const secp256k1_fe_t *a) {
r &= (d[2] <= 0xFFFFFFFFFFFFFULL * m);
r &= (d[3] <= 0xFFFFFFFFFFFFFULL * m);
r &= (d[4] <= 0x0FFFFFFFFFFFFULL * m);
r &= (a->magnitude >= 0);
if (a->normalized) {
r &= (m == 1);
r &= (a->magnitude <= 1);
if (r && (d[4] == 0x0FFFFFFFFFFFFULL) && ((d[3] & d[2] & d[1]) == 0xFFFFFFFFFFFFFULL)) {
r &= (d[0] < 0xFFFFEFFFFFC2FULL);
}
@@ -128,7 +129,7 @@ int static inline secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
void static inline secp256k1_fe_clear(secp256k1_fe_t *a) {
#ifdef VERIFY
a->magnitude = 0;
a->normalized = 0;
a->normalized = 1;
#endif
for (int i=0; i<5; i++) {
a->n[i] = 0;
@@ -210,6 +211,9 @@ void static inline secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
}
void static inline secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
#ifdef VERIFY
secp256k1_fe_verify(a);
#endif
r->n[0] += a->n[0];
r->n[1] += a->n[1];
r->n[2] += a->n[2];
@@ -219,7 +223,6 @@ void static inline secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a)
r->magnitude += a->magnitude;
r->normalized = 0;
secp256k1_fe_verify(r);
secp256k1_fe_verify(a);
#endif
}
@@ -241,11 +244,13 @@ void static secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const s
void static secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
secp256k1_fe_verify(a);
#endif
secp256k1_fe_sqr_inner(a->n, r->n);
#ifdef VERIFY
r->magnitude = 1;
r->normalized = 0;
secp256k1_fe_verify(r);
#endif
}