diff options
Diffstat (limited to 'crypto/ec/curve448/curve448.c')
| -rw-r--r-- | crypto/ec/curve448/curve448.c | 727 |
1 files changed, 727 insertions, 0 deletions
diff --git a/crypto/ec/curve448/curve448.c b/crypto/ec/curve448/curve448.c new file mode 100644 index 000000000000..7dc68c8853e1 --- /dev/null +++ b/crypto/ec/curve448/curve448.c @@ -0,0 +1,727 @@ +/* + * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2015-2016 Cryptography Research, Inc. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + * + * Originally written by Mike Hamburg + */ +#include <openssl/crypto.h> +#include "word.h" +#include "field.h" + +#include "point_448.h" +#include "ed448.h" +#include "curve448_lcl.h" + +#define COFACTOR 4 + +#define C448_WNAF_FIXED_TABLE_BITS 5 +#define C448_WNAF_VAR_TABLE_BITS 3 + +#define EDWARDS_D (-39081) + +static const curve448_scalar_t precomputed_scalarmul_adjustment = { + { + { + SC_LIMB(0xc873d6d54a7bb0cf), SC_LIMB(0xe933d8d723a70aad), + SC_LIMB(0xbb124b65129c96fd), SC_LIMB(0x00000008335dc163) + } + } +}; + +#define TWISTED_D (EDWARDS_D - 1) + +#define WBITS C448_WORD_BITS /* NB this may be different from ARCH_WORD_BITS */ + +/* Inverse. */ +static void gf_invert(gf y, const gf x, int assert_nonzero) +{ + mask_t ret; + gf t1, t2; + + gf_sqr(t1, x); /* o^2 */ + ret = gf_isr(t2, t1); /* +-1/sqrt(o^2) = +-1/o */ + (void)ret; + if (assert_nonzero) + assert(ret); + gf_sqr(t1, t2); + gf_mul(t2, t1, x); /* not direct to y in case of alias. */ + gf_copy(y, t2); +} + +/** identity = (0,1) */ +const curve448_point_t curve448_point_identity = + { {{{{0}}}, {{{1}}}, {{{1}}}, {{{0}}}} }; + +static void point_double_internal(curve448_point_t p, const curve448_point_t q, + int before_double) +{ + gf a, b, c, d; + + gf_sqr(c, q->x); + gf_sqr(a, q->y); + gf_add_nr(d, c, a); /* 2+e */ + gf_add_nr(p->t, q->y, q->x); /* 2+e */ + gf_sqr(b, p->t); + gf_subx_nr(b, b, d, 3); /* 4+e */ + gf_sub_nr(p->t, a, c); /* 3+e */ + gf_sqr(p->x, q->z); + gf_add_nr(p->z, p->x, p->x); /* 2+e */ + gf_subx_nr(a, p->z, p->t, 4); /* 6+e */ + if (GF_HEADROOM == 5) + gf_weak_reduce(a); /* or 1+e */ + gf_mul(p->x, a, b); + gf_mul(p->z, p->t, a); + gf_mul(p->y, p->t, d); + if (!before_double) + gf_mul(p->t, b, d); +} + +void curve448_point_double(curve448_point_t p, const curve448_point_t q) +{ + point_double_internal(p, q, 0); +} + +/* Operations on [p]niels */ +static ossl_inline void cond_neg_niels(niels_t n, mask_t neg) +{ + gf_cond_swap(n->a, n->b, neg); + gf_cond_neg(n->c, neg); +} + +static void pt_to_pniels(pniels_t b, const curve448_point_t a) +{ + gf_sub(b->n->a, a->y, a->x); + gf_add(b->n->b, a->x, a->y); + gf_mulw(b->n->c, a->t, 2 * TWISTED_D); + gf_add(b->z, a->z, a->z); +} + +static void pniels_to_pt(curve448_point_t e, const pniels_t d) +{ + gf eu; + + gf_add(eu, d->n->b, d->n->a); + gf_sub(e->y, d->n->b, d->n->a); + gf_mul(e->t, e->y, eu); + gf_mul(e->x, d->z, e->y); + gf_mul(e->y, d->z, eu); + gf_sqr(e->z, d->z); +} + +static void niels_to_pt(curve448_point_t e, const niels_t n) +{ + gf_add(e->y, n->b, n->a); + gf_sub(e->x, n->b, n->a); + gf_mul(e->t, e->y, e->x); + gf_copy(e->z, ONE); +} + +static void add_niels_to_pt(curve448_point_t d, const niels_t e, + int before_double) +{ + gf a, b, c; + + gf_sub_nr(b, d->y, d->x); /* 3+e */ + gf_mul(a, e->a, b); + gf_add_nr(b, d->x, d->y); /* 2+e */ + gf_mul(d->y, e->b, b); + gf_mul(d->x, e->c, d->t); + gf_add_nr(c, a, d->y); /* 2+e */ + gf_sub_nr(b, d->y, a); /* 3+e */ + gf_sub_nr(d->y, d->z, d->x); /* 3+e */ + gf_add_nr(a, d->x, d->z); /* 2+e */ + gf_mul(d->z, a, d->y); + gf_mul(d->x, d->y, b); + gf_mul(d->y, a, c); + if (!before_double) + gf_mul(d->t, b, c); +} + +static void sub_niels_from_pt(curve448_point_t d, const niels_t e, + int before_double) +{ + gf a, b, c; + + gf_sub_nr(b, d->y, d->x); /* 3+e */ + gf_mul(a, e->b, b); + gf_add_nr(b, d->x, d->y); /* 2+e */ + gf_mul(d->y, e->a, b); + gf_mul(d->x, e->c, d->t); + gf_add_nr(c, a, d->y); /* 2+e */ + gf_sub_nr(b, d->y, a); /* 3+e */ + gf_add_nr(d->y, d->z, d->x); /* 2+e */ + gf_sub_nr(a, d->z, d->x); /* 3+e */ + gf_mul(d->z, a, d->y); + gf_mul(d->x, d->y, b); + gf_mul(d->y, a, c); + if (!before_double) + gf_mul(d->t, b, c); +} + +static void add_pniels_to_pt(curve448_point_t p, const pniels_t pn, + int before_double) +{ + gf L0; + + gf_mul(L0, p->z, pn->z); + gf_copy(p->z, L0); + add_niels_to_pt(p, pn->n, before_double); +} + +static void sub_pniels_from_pt(curve448_point_t p, const pniels_t pn, + int before_double) +{ + gf L0; + + gf_mul(L0, p->z, pn->z); + gf_copy(p->z, L0); + sub_niels_from_pt(p, pn->n, before_double); +} + +c448_bool_t curve448_point_eq(const curve448_point_t p, + const curve448_point_t q) +{ + mask_t succ; + gf a, b; + + /* equality mod 2-torsion compares x/y */ + gf_mul(a, p->y, q->x); + gf_mul(b, q->y, p->x); + succ = gf_eq(a, b); + + return mask_to_bool(succ); +} + +c448_bool_t curve448_point_valid(const curve448_point_t p) +{ + mask_t out; + gf a, b, c; + + gf_mul(a, p->x, p->y); + gf_mul(b, p->z, p->t); + out = gf_eq(a, b); + gf_sqr(a, p->x); + gf_sqr(b, p->y); + gf_sub(a, b, a); + gf_sqr(b, p->t); + gf_mulw(c, b, TWISTED_D); + gf_sqr(b, p->z); + gf_add(b, b, c); + out &= gf_eq(a, b); + out &= ~gf_eq(p->z, ZERO); + return mask_to_bool(out); +} + +static ossl_inline void constant_time_lookup_niels(niels_s * RESTRICT ni, + const niels_t * table, + int nelts, int idx) +{ + constant_time_lookup(ni, table, sizeof(niels_s), nelts, idx); +} + +void curve448_precomputed_scalarmul(curve448_point_t out, + const curve448_precomputed_s * table, + const curve448_scalar_t scalar) +{ + unsigned int i, j, k; + const unsigned int n = COMBS_N, t = COMBS_T, s = COMBS_S; + niels_t ni; + curve448_scalar_t scalar1x; + + curve448_scalar_add(scalar1x, scalar, precomputed_scalarmul_adjustment); + curve448_scalar_halve(scalar1x, scalar1x); + + for (i = s; i > 0; i--) { + if (i != s) + point_double_internal(out, out, 0); + + for (j = 0; j < n; j++) { + int tab = 0; + mask_t invert; + + for (k = 0; k < t; k++) { + unsigned int bit = (i - 1) + s * (k + j * t); + + if (bit < C448_SCALAR_BITS) + tab |= + (scalar1x->limb[bit / WBITS] >> (bit % WBITS) & 1) << k; + } + + invert = (tab >> (t - 1)) - 1; + tab ^= invert; + tab &= (1 << (t - 1)) - 1; + + constant_time_lookup_niels(ni, &table->table[j << (t - 1)], + 1 << (t - 1), tab); + + cond_neg_niels(ni, invert); + if ((i != s) || j != 0) + add_niels_to_pt(out, ni, j == n - 1 && i != 1); + else + niels_to_pt(out, ni); + } + } + + OPENSSL_cleanse(ni, sizeof(ni)); + OPENSSL_cleanse(scalar1x, sizeof(scalar1x)); +} + +void curve448_point_mul_by_ratio_and_encode_like_eddsa( + uint8_t enc[EDDSA_448_PUBLIC_BYTES], + const curve448_point_t p) +{ + gf x, y, z, t; + curve448_point_t q; + + /* The point is now on the twisted curve. Move it to untwisted. */ + curve448_point_copy(q, p); + + { + /* 4-isogeny: 2xy/(y^+x^2), (y^2-x^2)/(2z^2-y^2+x^2) */ + gf u; + + gf_sqr(x, q->x); + gf_sqr(t, q->y); + gf_add(u, x, t); + gf_add(z, q->y, q->x); + gf_sqr(y, z); + gf_sub(y, y, u); + gf_sub(z, t, x); + gf_sqr(x, q->z); + gf_add(t, x, x); + gf_sub(t, t, z); + gf_mul(x, t, y); + gf_mul(y, z, u); + gf_mul(z, u, t); + OPENSSL_cleanse(u, sizeof(u)); + } + + /* Affinize */ + gf_invert(z, z, 1); + gf_mul(t, x, z); + gf_mul(x, y, z); + + /* Encode */ + enc[EDDSA_448_PRIVATE_BYTES - 1] = 0; + gf_serialize(enc, x, 1); + enc[EDDSA_448_PRIVATE_BYTES - 1] |= 0x80 & gf_lobit(t); + + OPENSSL_cleanse(x, sizeof(x)); + OPENSSL_cleanse(y, sizeof(y)); + OPENSSL_cleanse(z, sizeof(z)); + OPENSSL_cleanse(t, sizeof(t)); + curve448_point_destroy(q); +} + +c448_error_t curve448_point_decode_like_eddsa_and_mul_by_ratio( + curve448_point_t p, + const uint8_t enc[EDDSA_448_PUBLIC_BYTES]) +{ + uint8_t enc2[EDDSA_448_PUBLIC_BYTES]; + mask_t low; + mask_t succ; + + memcpy(enc2, enc, sizeof(enc2)); + + low = ~word_is_zero(enc2[EDDSA_448_PRIVATE_BYTES - 1] & 0x80); + enc2[EDDSA_448_PRIVATE_BYTES - 1] &= ~0x80; + + succ = gf_deserialize(p->y, enc2, 1, 0); + succ &= word_is_zero(enc2[EDDSA_448_PRIVATE_BYTES - 1]); + + gf_sqr(p->x, p->y); + gf_sub(p->z, ONE, p->x); /* num = 1-y^2 */ + gf_mulw(p->t, p->x, EDWARDS_D); /* dy^2 */ + gf_sub(p->t, ONE, p->t); /* denom = 1-dy^2 or 1-d + dy^2 */ + + gf_mul(p->x, p->z, p->t); + succ &= gf_isr(p->t, p->x); /* 1/sqrt(num * denom) */ + + gf_mul(p->x, p->t, p->z); /* sqrt(num / denom) */ + gf_cond_neg(p->x, gf_lobit(p->x) ^ low); + gf_copy(p->z, ONE); + + { + gf a, b, c, d; + + /* 4-isogeny 2xy/(y^2-ax^2), (y^2+ax^2)/(2-y^2-ax^2) */ + gf_sqr(c, p->x); + gf_sqr(a, p->y); + gf_add(d, c, a); + gf_add(p->t, p->y, p->x); + gf_sqr(b, p->t); + gf_sub(b, b, d); + gf_sub(p->t, a, c); + gf_sqr(p->x, p->z); + gf_add(p->z, p->x, p->x); + gf_sub(a, p->z, d); + gf_mul(p->x, a, b); + gf_mul(p->z, p->t, a); + gf_mul(p->y, p->t, d); + gf_mul(p->t, b, d); + OPENSSL_cleanse(a, sizeof(a)); + OPENSSL_cleanse(b, sizeof(b)); + OPENSSL_cleanse(c, sizeof(c)); + OPENSSL_cleanse(d, sizeof(d)); + } + + OPENSSL_cleanse(enc2, sizeof(enc2)); + assert(curve448_point_valid(p) || ~succ); + + return c448_succeed_if(mask_to_bool(succ)); +} + +c448_error_t x448_int(uint8_t out[X_PUBLIC_BYTES], + const uint8_t base[X_PUBLIC_BYTES], + const uint8_t scalar[X_PRIVATE_BYTES]) +{ + gf x1, x2, z2, x3, z3, t1, t2; + int t; + mask_t swap = 0; + mask_t nz; + + (void)gf_deserialize(x1, base, 1, 0); + gf_copy(x2, ONE); + gf_copy(z2, ZERO); + gf_copy(x3, x1); + gf_copy(z3, ONE); + + for (t = X_PRIVATE_BITS - 1; t >= 0; t--) { + uint8_t sb = scalar[t / 8]; + mask_t k_t; + + /* Scalar conditioning */ + if (t / 8 == 0) + sb &= -(uint8_t)COFACTOR; + else if (t == X_PRIVATE_BITS - 1) + sb = -1; + + k_t = (sb >> (t % 8)) & 1; + k_t = 0 - k_t; /* set to all 0s or all 1s */ + + swap ^= k_t; + gf_cond_swap(x2, x3, swap); + gf_cond_swap(z2, z3, swap); + swap = k_t; + + /* + * The "_nr" below skips coefficient reduction. In the following + * comments, "2+e" is saying that the coefficients are at most 2+epsilon + * times the reduction limit. + */ + gf_add_nr(t1, x2, z2); /* A = x2 + z2 */ /* 2+e */ + gf_sub_nr(t2, x2, z2); /* B = x2 - z2 */ /* 3+e */ + gf_sub_nr(z2, x3, z3); /* D = x3 - z3 */ /* 3+e */ + gf_mul(x2, t1, z2); /* DA */ + gf_add_nr(z2, z3, x3); /* C = x3 + z3 */ /* 2+e */ + gf_mul(x3, t2, z2); /* CB */ + gf_sub_nr(z3, x2, x3); /* DA-CB */ /* 3+e */ + gf_sqr(z2, z3); /* (DA-CB)^2 */ + gf_mul(z3, x1, z2); /* z3 = x1(DA-CB)^2 */ + gf_add_nr(z2, x2, x3); /* (DA+CB) */ /* 2+e */ + gf_sqr(x3, z2); /* x3 = (DA+CB)^2 */ + + gf_sqr(z2, t1); /* AA = A^2 */ + gf_sqr(t1, t2); /* BB = B^2 */ + gf_mul(x2, z2, t1); /* x2 = AA*BB */ + gf_sub_nr(t2, z2, t1); /* E = AA-BB */ /* 3+e */ + + gf_mulw(t1, t2, -EDWARDS_D); /* E*-d = a24*E */ + gf_add_nr(t1, t1, z2); /* AA + a24*E */ /* 2+e */ + gf_mul(z2, t2, t1); /* z2 = E(AA+a24*E) */ + } + + /* Finish */ + gf_cond_swap(x2, x3, swap); + gf_cond_swap(z2, z3, swap); + gf_invert(z2, z2, 0); + gf_mul(x1, x2, z2); + gf_serialize(out, x1, 1); + nz = ~gf_eq(x1, ZERO); + + OPENSSL_cleanse(x1, sizeof(x1)); + OPENSSL_cleanse(x2, sizeof(x2)); + OPENSSL_cleanse(z2, sizeof(z2)); + OPENSSL_cleanse(x3, sizeof(x3)); + OPENSSL_cleanse(z3, sizeof(z3)); + OPENSSL_cleanse(t1, sizeof(t1)); + OPENSSL_cleanse(t2, sizeof(t2)); + + return c448_succeed_if(mask_to_bool(nz)); +} + +void curve448_point_mul_by_ratio_and_encode_like_x448(uint8_t + out[X_PUBLIC_BYTES], + const curve448_point_t p) +{ + curve448_point_t q; + + curve448_point_copy(q, p); + gf_invert(q->t, q->x, 0); /* 1/x */ + gf_mul(q->z, q->t, q->y); /* y/x */ + gf_sqr(q->y, q->z); /* (y/x)^2 */ + gf_serialize(out, q->y, 1); + curve448_point_destroy(q); +} + +void x448_derive_public_key(uint8_t out[X_PUBLIC_BYTES], + const uint8_t scalar[X_PRIVATE_BYTES]) +{ + /* Scalar conditioning */ + uint8_t scalar2[X_PRIVATE_BYTES]; + curve448_scalar_t the_scalar; + curve448_point_t p; + unsigned int i; + + memcpy(scalar2, scalar, sizeof(scalar2)); + scalar2[0] &= -(uint8_t)COFACTOR; + + scalar2[X_PRIVATE_BYTES - 1] &= ~((0u - 1u) << ((X_PRIVATE_BITS + 7) % 8)); + scalar2[X_PRIVATE_BYTES - 1] |= 1 << ((X_PRIVATE_BITS + 7) % 8); + + curve448_scalar_decode_long(the_scalar, scalar2, sizeof(scalar2)); + + /* Compensate for the encoding ratio */ + for (i = 1; i < X448_ENCODE_RATIO; i <<= 1) + curve448_scalar_halve(the_scalar, the_scalar); + + curve448_precomputed_scalarmul(p, curve448_precomputed_base, the_scalar); + curve448_point_mul_by_ratio_and_encode_like_x448(out, p); + curve448_point_destroy(p); +} + +/* Control for variable-time scalar multiply algorithms. */ +struct smvt_control { + int power, addend; +}; + +#if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 3)) +# define NUMTRAILINGZEROS __builtin_ctz +#else +# define NUMTRAILINGZEROS numtrailingzeros +static uint32_t numtrailingzeros(uint32_t i) +{ + uint32_t tmp; + uint32_t num = 31; + + if (i == 0) + return 32; + + tmp = i << 16; + if (tmp != 0) { + i = tmp; + num -= 16; + } + tmp = i << 8; + if (tmp != 0) { + i = tmp; + num -= 8; + } + tmp = i << 4; + if (tmp != 0) { + i = tmp; + num -= 4; + } + tmp = i << 2; + if (tmp != 0) { + i = tmp; + num -= 2; + } + tmp = i << 1; + if (tmp != 0) + num--; + + return num; +} +#endif + +static int recode_wnaf(struct smvt_control *control, + /* [nbits/(table_bits + 1) + 3] */ + const curve448_scalar_t scalar, + unsigned int table_bits) +{ + unsigned int table_size = C448_SCALAR_BITS / (table_bits + 1) + 3; + int position = table_size - 1; /* at the end */ + uint64_t current = scalar->limb[0] & 0xFFFF; + uint32_t mask = (1 << (table_bits + 1)) - 1; + unsigned int w; + const unsigned int B_OVER_16 = sizeof(scalar->limb[0]) / 2; + unsigned int n, i; + + /* place the end marker */ + control[position].power = -1; + control[position].addend = 0; + position--; + + /* + * PERF: Could negate scalar if it's large. But then would need more cases + * in the actual code that uses it, all for an expected reduction of like + * 1/5 op. Probably not worth it. + */ + + for (w = 1; w < (C448_SCALAR_BITS - 1) / 16 + 3; w++) { + if (w < (C448_SCALAR_BITS - 1) / 16 + 1) { + /* Refill the 16 high bits of current */ + current += (uint32_t)((scalar->limb[w / B_OVER_16] + >> (16 * (w % B_OVER_16))) << 16); + } + + while (current & 0xFFFF) { + uint32_t pos = NUMTRAILINGZEROS((uint32_t)current); + uint32_t odd = (uint32_t)current >> pos; + int32_t delta = odd & mask; + + assert(position >= 0); + if (odd & (1 << (table_bits + 1))) + delta -= (1 << (table_bits + 1)); + current -= delta * (1 << pos); + control[position].power = pos + 16 * (w - 1); + control[position].addend = delta; + position--; + } + current >>= 16; + } + assert(current == 0); + + position++; + n = table_size - position; + for (i = 0; i < n; i++) + control[i] = control[i + position]; + + return n - 1; +} + +static void prepare_wnaf_table(pniels_t * output, + const curve448_point_t working, + unsigned int tbits) +{ + curve448_point_t tmp; + int i; + pniels_t twop; + + pt_to_pniels(output[0], working); + + if (tbits == 0) + return; + + curve448_point_double(tmp, working); + pt_to_pniels(twop, tmp); + + add_pniels_to_pt(tmp, output[0], 0); + pt_to_pniels(output[1], tmp); + + for (i = 2; i < 1 << tbits; i++) { + add_pniels_to_pt(tmp, twop, 0); + pt_to_pniels(output[i], tmp); + } + + curve448_point_destroy(tmp); + OPENSSL_cleanse(twop, sizeof(twop)); +} + +void curve448_base_double_scalarmul_non_secret(curve448_point_t combo, + const curve448_scalar_t scalar1, + const curve448_point_t base2, + const curve448_scalar_t scalar2) +{ + const int table_bits_var = C448_WNAF_VAR_TABLE_BITS; + const int table_bits_pre = C448_WNAF_FIXED_TABLE_BITS; + struct smvt_control control_var[C448_SCALAR_BITS / + (C448_WNAF_VAR_TABLE_BITS + 1) + 3]; + struct smvt_control control_pre[C448_SCALAR_BITS / + (C448_WNAF_FIXED_TABLE_BITS + 1) + 3]; + int ncb_pre = recode_wnaf(control_pre, scalar1, table_bits_pre); + int ncb_var = recode_wnaf(control_var, scalar2, table_bits_var); + pniels_t precmp_var[1 << C448_WNAF_VAR_TABLE_BITS]; + int contp = 0, contv = 0, i; + + prepare_wnaf_table(precmp_var, base2, table_bits_var); + i = control_var[0].power; + + if (i < 0) { + curve448_point_copy(combo, curve448_point_identity); + return; + } + if (i > control_pre[0].power) { + pniels_to_pt(combo, precmp_var[control_var[0].addend >> 1]); + contv++; + } else if (i == control_pre[0].power && i >= 0) { + pniels_to_pt(combo, precmp_var[control_var[0].addend >> 1]); + add_niels_to_pt(combo, curve448_wnaf_base[control_pre[0].addend >> 1], + i); + contv++; + contp++; + } else { + i = control_pre[0].power; + niels_to_pt(combo, curve448_wnaf_base[control_pre[0].addend >> 1]); + contp++; + } + + for (i--; i >= 0; i--) { + int cv = (i == control_var[contv].power); + int cp = (i == control_pre[contp].power); + + point_double_internal(combo, combo, i && !(cv || cp)); + + if (cv) { + assert(control_var[contv].addend); + + if (control_var[contv].addend > 0) + add_pniels_to_pt(combo, + precmp_var[control_var[contv].addend >> 1], + i && !cp); + else + sub_pniels_from_pt(combo, + precmp_var[(-control_var[contv].addend) + >> 1], i && !cp); + contv++; + } + + if (cp) { + assert(control_pre[contp].addend); + + if (control_pre[contp].addend > 0) + add_niels_to_pt(combo, + curve448_wnaf_base[control_pre[contp].addend + >> 1], i); + else + sub_niels_from_pt(combo, + curve448_wnaf_base[(-control_pre + [contp].addend) >> 1], i); + contp++; + } + } + + /* This function is non-secret, but whatever this is cheap. */ + OPENSSL_cleanse(control_var, sizeof(control_var)); + OPENSSL_cleanse(control_pre, sizeof(control_pre)); + OPENSSL_cleanse(precmp_var, sizeof(precmp_var)); + + assert(contv == ncb_var); + (void)ncb_var; + assert(contp == ncb_pre); + (void)ncb_pre; +} + +void curve448_point_destroy(curve448_point_t point) +{ + OPENSSL_cleanse(point, sizeof(curve448_point_t)); +} + +int X448(uint8_t out_shared_key[56], const uint8_t private_key[56], + const uint8_t peer_public_value[56]) +{ + return x448_int(out_shared_key, peer_public_value, private_key) + == C448_SUCCESS; +} + +void X448_public_from_private(uint8_t out_public_value[56], + const uint8_t private_key[56]) +{ + x448_derive_public_key(out_public_value, private_key); +} |