diff options
Diffstat (limited to 'src/ec25519.c')
-rw-r--r-- | src/ec25519.c | 60 |
1 files changed, 41 insertions, 19 deletions
diff --git a/src/ec25519.c b/src/ec25519.c index bfb49a0..915bd2c 100644 --- a/src/ec25519.c +++ b/src/ec25519.c @@ -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; - - 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]; +void ecc_25519_store_packed(ecc_int_256 *out, const ecc_25519_work *in) { + ecc_int_256 y; - 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); } |