Add Curve25519 based on curve25519-donna by Adam Langley.

This uses only the c64 version from curve25519-donna; on systems that
don't have a native uint128_t type, a donna128 type stands in for just
enough 128-bit operations to satisfy donna.cpp

1 files changed, 56 insertions, 0 deletions

diff --git a/src/tests/test_c25519.cpp b/src/tests/test_c25519.cpp
new file mode 100644
index 000000000..cb03ebf69
--- /dev/null
+++ b/src/tests/test_c25519.cpp
@@ -0,0 +1,56 @@
+#include "tests.h"
+#include "test_pubkey.h"
+
+#if defined(BOTAN_HAS_CURVE_25519)
+#include <botan/curve25519.h>
+#include <botan/hex.h>
+#include <iostream>
+#include <fstream>
+#endif
+
+using namespace Botan;
+
+#if defined(BOTAN_HAS_CURVE_25519)
+
+namespace {
+
+size_t curve25519_scalar_kat(const std::string& secret_h,
+                             const std::string& basepoint_h,
+                             const std::string& out_h)
+   {
+   const std::vector<byte> secret = hex_decode(secret_h);
+   const std::vector<byte> basepoint = hex_decode(basepoint_h);
+   const std::vector<byte> out = hex_decode(out_h);
+
+   std::vector<byte> got(32);
+   curve25519_donna(&got[0], &secret[0], &basepoint[0]);
+
+   if(got != out)
+      {
+      std::cout << "Got " << hex_encode(got) << " exp " << hex_encode(out) << "\n";
+      return 1;
+      }
+
+   return 0;
+   }
+
+}
+#endif
+
+size_t test_curve25519()
+   {
+   size_t fails = 0;
+
+#if defined(BOTAN_HAS_CURVE_25519)
+   std::ifstream c25519_scalar(PK_TEST_DATA_DIR "/c25519_scalar.vec");
+
+   fails += run_tests_bb(c25519_scalar, "Curve25519 ScalarMult", "Out", true,
+             [](std::map<std::string, std::string> m) -> size_t
+             {
+             return curve25519_scalar_kat(m["Secret"], m["Basepoint"], m["Out"]);
+             });
+#endif
+
+   return fails;
+   }
+