diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/ec25519.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/src/ec25519.c b/src/ec25519.c index b9ca4e9..dfb806b 100644 --- a/src/ec25519.c +++ b/src/ec25519.c @@ -387,10 +387,10 @@ void ecc_25519_store(ecc_public_key_256 *out, const ecc_25519_work *in) { out->p[31] |= (y[0] << 7); } -static const ecc_25519_work infty = {{0}, {0}, {1}}; +static const ecc_25519_work id = {{1}, {0}, {0}}; -int ecc_25519_is_infinity(const ecc_25519_work *in) { - return (check_zero(in->X)|check_zero(in->Y)); +int ecc_25519_is_identity(const ecc_25519_work *in) { + return (check_zero(in->X)|check_zero(in->Y)|check_zero(in->Z)); } void ecc_25519_double(ecc_25519_work *out, const ecc_25519_work *in) { @@ -411,11 +411,12 @@ void ecc_25519_double(ecc_25519_work *out, const ecc_25519_work *in) { sub(t5, C, t4); mult(out->Y, E, t5); mult(out->Z, D, E); - selectw(out, out, &infty, ecc_25519_is_infinity(out)); + selectw(out, out, &id, ecc_25519_is_identity(out)); } void ecc_25519_add(ecc_25519_work *out, const ecc_25519_work *in1, const ecc_25519_work *in2) { unsigned int A[32], B[32], C[32], D[32], E[32], H[32], I[32], t0[32], t1[32], t2[32], t3[32], t4[32], t5[32], t6[32], t7[32], t8[32]; + int id1 = ecc_25519_is_identity(in1), id2 = ecc_25519_is_identity(in2); mult(A, in1->Z, in2->Z); square(t0, A); @@ -436,8 +437,8 @@ void ecc_25519_add(ecc_25519_work *out, const ecc_25519_work *in1, const ecc_255 mult(out->Y, t7, I); mult(t8, H, I); mult(out->Z, A, t8); - selectw(out, out, in1, check_zero(t3)); - selectw(out, out, in2, check_zero(t2)); + selectw(out, out, in1, id2); + selectw(out, out, in2, id1); } void ecc_25519_scalarmult(ecc_25519_work *out, const ecc_secret_key_256 *n, const ecc_25519_work *base) { |