Skip to content

f can never equal -m #1603

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 8, 2024
Merged

f can never equal -m #1603

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 4 additions & 6 deletions src/modinv32_impl.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -565,13 +565,12 @@ static void secp256k1_modinv32(secp256k1_modinv32_signed30 *x, const secp256k1_m

/* g == 0 */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, 9, &SECP256K1_SIGNED30_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
/* |f| == 1, or (x == 0 and d == 0 and f == modulus) */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, 9, &SECP256K1_SIGNED30_ONE, -1) == 0 ||
secp256k1_modinv32_mul_cmp_30(&f, 9, &SECP256K1_SIGNED30_ONE, 1) == 0 ||
(secp256k1_modinv32_mul_cmp_30(x, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 &&
secp256k1_modinv32_mul_cmp_30(&d, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 &&
(secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, -1) == 0)));
secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, 1) == 0));

/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv32_normalize_30(&d, f.v[8], modinfo);
Expand Down Expand Up @@ -643,13 +642,12 @@ static void secp256k1_modinv32_var(secp256k1_modinv32_signed30 *x, const secp256

/* g == 0 */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &SECP256K1_SIGNED30_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
/* |f| == 1, or (x == 0 and d == 0 and f == modulus) */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &SECP256K1_SIGNED30_ONE, -1) == 0 ||
secp256k1_modinv32_mul_cmp_30(&f, len, &SECP256K1_SIGNED30_ONE, 1) == 0 ||
(secp256k1_modinv32_mul_cmp_30(x, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 &&
secp256k1_modinv32_mul_cmp_30(&d, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 &&
(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, -1) == 0)));
secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) == 0));

/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv32_normalize_30(&d, f.v[len - 1], modinfo);
Expand Down
10 changes: 4 additions & 6 deletions src/modinv64_impl.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -621,13 +621,12 @@ static void secp256k1_modinv64(secp256k1_modinv64_signed62 *x, const secp256k1_m

/* g == 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &SECP256K1_SIGNED62_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
/* |f| == 1, or (x == 0 and d == 0 and f == modulus) */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, 5, &SECP256K1_SIGNED62_ONE, -1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, 5, &SECP256K1_SIGNED62_ONE, 1) == 0 ||
(secp256k1_modinv64_mul_cmp_62(x, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
secp256k1_modinv64_mul_cmp_62(&d, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, -1) == 0)));
secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, 1) == 0));

/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv64_normalize_62(&d, f.v[4], modinfo);
Expand Down Expand Up @@ -698,13 +697,12 @@ static void secp256k1_modinv64_var(secp256k1_modinv64_signed62 *x, const secp256

/* g == 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &SECP256K1_SIGNED62_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
/* |f| == 1, or (x == 0 and d == 0 and f == modulus) */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &SECP256K1_SIGNED62_ONE, -1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, len, &SECP256K1_SIGNED62_ONE, 1) == 0 ||
(secp256k1_modinv64_mul_cmp_62(x, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
secp256k1_modinv64_mul_cmp_62(&d, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, -1) == 0)));
secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) == 0));

/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv64_normalize_62(&d, f.v[len - 1], modinfo);
Expand Down
Loading