shared/ecc: Make ecc_make_key() a stand alone API
And correct minor flaws in API descriptions
diff --git a/src/shared/ecc.c b/src/shared/ecc.c
index 15f6b8a..8149f1d 100644
--- a/src/shared/ecc.c
+++ b/src/shared/ecc.c
@@ -883,20 +883,29 @@
bool ecc_make_key(uint8_t public_key[64], uint8_t private_key[32])
{
+ struct ecc_point pk;
uint64_t priv[NUM_ECC_DIGITS];
unsigned int tries = 0;
- bool result = false;
- for (tries = 0; !result && tries < MAX_TRIES; tries++) {
- if (!get_random_number(priv))
+ do {
+ if (!get_random_number(priv) || (tries++ >= MAX_TRIES))
+ return false;
+
+ if (vli_is_zero(priv))
continue;
- ecc_native2bytes(priv, private_key);
+ /* Make sure the private key is in the range [1, n-1]. */
+ if (vli_cmp(curve_n, priv) != 1)
+ continue;
- result = ecc_make_public_key(private_key, public_key);
- }
+ ecc_point_mult(&pk, &curve_g, priv, NULL, vli_num_bits(priv));
+ } while (ecc_point_is_zero(&pk));
- return result;
+ ecc_native2bytes(priv, private_key);
+ ecc_native2bytes(pk.x, public_key);
+ ecc_native2bytes(pk.y, &public_key[32]);
+
+ return true;
}
bool ecc_valid_public_key(const uint8_t public_key[64])
diff --git a/src/shared/ecc.h b/src/shared/ecc.h
index a88e735..8c15e4e 100644
--- a/src/shared/ecc.h
+++ b/src/shared/ecc.h
@@ -29,8 +29,10 @@
/* Create a public key from a private key.
*
+ * Inputs:
+ * private_key - Your private key.
+ *
* Outputs:
- * private_key - Const private key
* public_key - Will be filled in with the public key.
*
* Returns true if the public key was generated successfully, false