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Reworked the API

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This commit is contained in:
Matthias Schiffer 2012-12-07 19:07:37 +01:00
parent f67c3f36b9
commit bccf64ec1b
4 changed files with 96 additions and 58 deletions
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60
src/ec25519.c
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@ -347,7 +347,40 @@ static void recip(unsigned int out[32], const unsigned int z[32]) {
/* 2^255 - 21 */ mult(out, t1, z11);
}
void ecc_25519_load(ecc_25519_work *out, const ecc_public_key_256 *in) {
void ecc_25519_load_xy(ecc_25519_work *out, const ecc_int_256 *x, const ecc_int_256 *y) {
int i;
for (i = 0; i < 32; i++) {
out->X[i] = x->p[i];
out->Y[i] = y->p[i];
out->Z[i] = (i == 0);
}
mult(out->T, out->X, out->Y);
}
void ecc_25519_store_xy(ecc_int_256 *x, ecc_int_256 *y, const ecc_25519_work *in) {
unsigned int X[32], Y[32], Z[32];
int i;
recip(Z, in->Z);
if (x) {
mult(X, Z, in->X);
freeze(X);
for (i = 0; i < 32; i++)
x->p[i] = X[i];
}
if (y) {
mult(Y, Z, in->Y);
freeze(Y);
for (i = 0; i < 32; i++)
y->p[i] = Y[i];
}
}
void ecc_25519_load_packed(ecc_25519_work *out, const ecc_int_256 *in) {
static const unsigned int zero[32] = {0};
static const unsigned int one[32] = {1};
@ -377,22 +410,11 @@ void ecc_25519_load(ecc_25519_work *out, const ecc_public_key_256 *in) {
mult(out->T, out->X, out->Y);
}
void ecc_25519_store(ecc_public_key_256 *out, const ecc_25519_work *in) {
unsigned int x[32], y[32], z[32];
int i;
void ecc_25519_store_packed(ecc_int_256 *out, const ecc_25519_work *in) {
ecc_int_256 y;
recip(z, in->Z);
mult(x, z, in->X);
mult(y, z, in->Y);
freeze(x);
freeze(y);
for (i = 0; i < 32; i++)
out->p[i] = x[i];
out->p[31] |= (y[0] << 7);
ecc_25519_store_xy(out, &y, in);
out->p[31] |= (y.p[0] << 7);
}
static const ecc_25519_work id = {{0}, {1}, {1}, {0}};
@ -450,13 +472,13 @@ void ecc_25519_add(ecc_25519_work *out, const ecc_25519_work *in1, const ecc_255
mult(out->Z, F, G);
}
void ecc_25519_scalarmult(ecc_25519_work *out, const ecc_secret_key_256 *n, const ecc_25519_work *base) {
void ecc_25519_scalarmult(ecc_25519_work *out, const ecc_int_256 *n, const ecc_25519_work *base) {
ecc_25519_work Q2, Q2p;
ecc_25519_work cur = id;
int b, pos;
for (pos = 255; pos >= 0; --pos) {
b = n->s[pos / 8] >> (pos & 7);
b = n->p[pos / 8] >> (pos & 7);
b &= 1;
ecc_25519_double(&Q2, &cur);
@ -483,6 +505,6 @@ static const ecc_25519_work default_base = {
0x47, 0x4b, 0x4c, 0x81, 0xa6, 0x02, 0xfd, 0x29}
};
void ecc_25519_scalarmult_base(ecc_25519_work *out, const ecc_secret_key_256 *n) {
void ecc_25519_scalarmult_base(ecc_25519_work *out, const ecc_int_256 *n) {
ecc_25519_scalarmult(out, n, &default_base);
}