diff options
Diffstat (limited to 'src/field_10x26_impl.h')
| -rw-r--r-- | src/field_10x26_impl.h | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h index 21742bf6eb..46b72ce78d 100644 --- a/src/field_10x26_impl.h +++ b/src/field_10x26_impl.h @@ -7,6 +7,7 @@ #ifndef SECP256K1_FIELD_REPR_IMPL_H #define SECP256K1_FIELD_REPR_IMPL_H +#include "checkmem.h" #include "util.h" #include "field.h" #include "modinv32_impl.h" @@ -481,6 +482,20 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_f #endif } +SECP256K1_INLINE static void secp256k1_fe_add_int(secp256k1_fe *r, int a) { +#ifdef VERIFY + secp256k1_fe_verify(r); + VERIFY_CHECK(a >= 0); + VERIFY_CHECK(a <= 0x7FFF); +#endif + r->n[0] += a; +#ifdef VERIFY + r->magnitude += 1; + r->normalized = 0; + secp256k1_fe_verify(r); +#endif +} + #if defined(USE_EXTERNAL_ASM) /* External assembler implementation */ @@ -1132,7 +1147,7 @@ static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a) { static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag) { uint32_t mask0, mask1; - VG_CHECK_VERIFY(r->n, sizeof(r->n)); + SECP256K1_CHECKMEM_CHECK_VERIFY(r->n, sizeof(r->n)); mask0 = flag + ~((uint32_t)0); mask1 = ~mask0; r->n[0] = (r->n[0] & mask0) | (a->n[0] & mask1); @@ -1231,7 +1246,7 @@ static SECP256K1_INLINE void secp256k1_fe_half(secp256k1_fe *r) { static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag) { uint32_t mask0, mask1; - VG_CHECK_VERIFY(r->n, sizeof(r->n)); + SECP256K1_CHECKMEM_CHECK_VERIFY(r->n, sizeof(r->n)); mask0 = flag + ~((uint32_t)0); mask1 = ~mask0; r->n[0] = (r->n[0] & mask0) | (a->n[0] & mask1); @@ -1364,4 +1379,31 @@ static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *x) { VERIFY_CHECK(secp256k1_fe_normalizes_to_zero(r) == secp256k1_fe_normalizes_to_zero(&tmp)); } +static int secp256k1_fe_is_square_var(const secp256k1_fe *x) { + secp256k1_fe tmp; + secp256k1_modinv32_signed30 s; + int jac, ret; + + tmp = *x; + secp256k1_fe_normalize_var(&tmp); + /* secp256k1_jacobi32_maybe_var cannot deal with input 0. */ + if (secp256k1_fe_is_zero(&tmp)) return 1; + secp256k1_fe_to_signed30(&s, &tmp); + jac = secp256k1_jacobi32_maybe_var(&s, &secp256k1_const_modinfo_fe); + if (jac == 0) { + /* secp256k1_jacobi32_maybe_var failed to compute the Jacobi symbol. Fall back + * to computing a square root. This should be extremely rare with random + * input (except in VERIFY mode, where a lower iteration count is used). */ + secp256k1_fe dummy; + ret = secp256k1_fe_sqrt(&dummy, &tmp); + } else { +#ifdef VERIFY + secp256k1_fe dummy; + VERIFY_CHECK(jac == 2*secp256k1_fe_sqrt(&dummy, &tmp) - 1); +#endif + ret = jac >= 0; + } + return ret; +} + #endif /* SECP256K1_FIELD_REPR_IMPL_H */ |