merging the embedded/main into nearby SDK

embedded/common/source/micro-ecc/Makefile

@@ -0,0 +1,6 @@
+all:
+	gcc -DuECC_ENABLE_VLI_API=1 -DuECC_VLI_NATIVE_LITTLE_ENDIAN=1 -DuECC_SUPPORTS_secp160r1=1 -c -o uECC.o uECC.c
+	ar rcs libmicro-ecc.a uECC.o
+	cp libmicro-ecc.a ../../../out/gLinux/third_party/micro-ecc
+ clean:
+	rm -f libmicro-ecc.a

embedded/common/source/micro-ecc/micro-ecc.c

@@ -0,0 +1,69 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#include <nearby.h>
+#include <uECC.h>
+#include <uECC_vli.h>
+
+#include "nearby_fp_library.h"
+#include "nearby_platform_se.h"
+#include "nearby_trace.h"
+
+nearby_platform_status nearby_platform_GetSecp160r1PublicKey(
+    const uint8_t private_key[32], uint8_t output[20],
+    uint8_t *hashed_flag_field) {
+  uECC_Curve curve = uECC_secp160r1();
+  uint8_t public_key[40];
+  uint8_t priv[48];
+
+  memset(priv, 0, 48);
+  memset(public_key, 0, 40);
+  memset(output, 0, 20);
+  for (int i = 0; i < 32; i++) {
+    priv[i] = private_key[31 - i];
+  }
+
+  uECC_vli_mmod((uECC_word_t *)priv, (uECC_word_t *)priv, uECC_curve_n(curve),
+                uECC_curve_num_n_words(curve));
+
+  // r should be aligned to the curve’s size: zeros should be added as most
+  // significant bits if its representation is shorter than 160/256 bits, or the
+  // most significant bits should be truncated if its representation is larger
+  // than 160/256 bits.
+  // make sure big endian format is passed as SHA256 input
+  for (int i = 0; i < 20; i++) {
+    output[i] = priv[19 - i];
+  }
+
+  if (nearby_fp_Sha256(public_key, output, 20) != kNearbyStatusOK) {
+    NEARBY_TRACE(ERROR, "failed to generate hashed field");
+    *hashed_flag_field = 0;
+  } else {
+    // the least significant byte of SHA256(r)
+    *hashed_flag_field = public_key[31];
+  }
+
+  memset(public_key, 0, 40);
+  int ret = uECC_compute_public_key(priv, public_key, curve);
+
+  memset(output, 0, 20);
+  if (ret == 1) {
+    NEARBY_TRACE(INFO, "public key generated");
+    for (int i = 0; i < 20; i++) {
+      output[i] = public_key[19 - i];
+    }
+    return kNearbyStatusOK;
+  }
+  NEARBY_TRACE(ERROR, "failed to generate public key: %d", ret);
+  return kNearbyStatusError;
+}