Fix failed self test when NO_OS_DEPENDENCE (GH #761)

Add is_clamped for secret key validation.

Cleanup paramter names in Donna::curve25519 to follow function.

Overload Donna::curve25519 to implicitly use base point if not provided.

Add additional asserts to let the code debug itself.

Update documentation.

1 files changed, 12 insertions, 6 deletions

diff --git a/donna_32.cpp b/donna_32.cpp
index 08bff4dd..69c7e2f8 100644
--- a/donna_32.cpp
+++ b/donna_32.cpp
@@ -873,23 +873,29 @@ ANONYMOUS_NAMESPACE_END
 NAMESPACE_BEGIN(CryptoPP)

 NAMESPACE_BEGIN(Donna)

 

-int curve25519(byte pubkey[32], const byte seckey[32], const byte basepoint[32])

+int curve25519(byte publicKey[32], const byte secretKey[32])

+{

+  const byte basePoint[32] = {9};

+  return curve25519(publicKey, secretKey, basePoint);

+}

+

+int curve25519(byte sharedKey[32], const byte secretKey[32], const byte othersKey[32])

 {

   limb bp[10], x[10], z[11], zmone[10];

-  byte e[32]; int i;

+  byte e[32];

 

-  for (i = 0; i < 32; ++i)

-    e[i] = seckey[i];

+  for (unsigned int i = 0; i < 32; ++i)

+    e[i] = secretKey[i];

 

   e[0] &= 248;

   e[31] &= 127;

   e[31] |= 64;

 

-  fexpand(bp, basepoint);

+  fexpand(bp, othersKey);

   cmult(x, z, e, bp);

   crecip(zmone, z);

   fmul(z, x, zmone);

-  fcontract(pubkey, z);

+  fcontract(sharedKey, z);

   return 0;

 }