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authorMatthias Schiffer <mschiffer@universe-factory.net>2012-12-07 19:07:37 +0100
committerMatthias Schiffer <mschiffer@universe-factory.net>2012-12-07 19:07:37 +0100
commitbccf64ec1b9b1b139259c03907f00d97430d43c5 (patch)
tree9f3cb6f5fb0d498c596f446968923c748034531c /src/ec25519.c
parentf67c3f36b9c4a2ab90bf7cf1380ecdb58528a133 (diff)
downloadlibuecc-bccf64ec1b9b1b139259c03907f00d97430d43c5.tar
libuecc-bccf64ec1b9b1b139259c03907f00d97430d43c5.zip
Reworked the API
Diffstat (limited to 'src/ec25519.c')
-rw-r--r--src/ec25519.c60
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);
}