add ffi c edwards25519

ffi/ffi_c/ffi_c_ecc_edwards25519/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "wedpr_ffi_c_edwards25519"
+version = "1.0.0"
+authors = [ "WeDPR <[email protected]>" ]
+edition = "2018"
+
+[lib]
+name = "ffi_c_edwards25519"
+crate-type = [ "cdylib", "staticlib" ]
+
+[dependencies]
+libc = "0.2.60"
+ecc_edwards25519 = { path = "../../../crypto/ecc/ecc_edwards25519" }
+wedpr_ffi_common = { path = "../../ffi_common" }
+
+# This is required to generate C/C++ header files.
+[build-dependencies]
+cbindgen = "0.9.0"

ffi/ffi_c/ffi_c_ecc_edwards25519/src/lib.rs

@@ -0,0 +1,51 @@
+//! Library of FFI of wedpr_crypto wrapper functions, targeting C/C++
+//! compatible architectures (including iOS), with fast binary interfaces.
+// Copyright 2020 WeDPR Lab Project Authors. Licensed under Apache-2.0.
+
+use ecc_edwards25519::{hash_to_curve, point_scalar_multi, random_scalar};
+
+use wedpr_ffi_common::utils::{
+    c_read_raw_pointer, c_write_raw_pointer, CInputBuffer, COutputBuffer,
+    SUCCESS,
+};
+
+#[no_mangle]
+/// C interface for 'wedpr_random_scalar'.
+pub unsafe extern "C" fn wedpr_random_scalar(
+    output_ciphertext: &mut COutputBuffer,
+) -> i8 {
+    let random_scalar = random_scalar();
+    c_write_raw_pointer(&random_scalar, output_ciphertext);
+    SUCCESS
+}
+
+#[no_mangle]
+/// C interface for 'wedpr_hash_to_curve'.
+pub unsafe extern "C" fn wedpr_hash_to_curve(
+    raw_message: &CInputBuffer,
+    output_ciphertext: &mut COutputBuffer,
+) -> i8 {
+    let plaintext = c_read_raw_pointer(raw_message);
+
+    let message = hash_to_curve(&plaintext);
+    std::mem::forget(raw_message);
+
+    c_write_raw_pointer(&message, output_ciphertext);
+    SUCCESS
+}
+
+#[no_mangle]
+/// C interface for 'wedpr_point_scalar_multi'.
+pub unsafe extern "C" fn wedpr_point_scalar_multi(
+    raw_point: &CInputBuffer,
+    raw_scalar: &CInputBuffer,
+    output_ciphertext: &mut COutputBuffer,
+) -> i8 {
+    let num_point = c_read_raw_pointer(raw_point);
+    let num_scalar = c_read_raw_pointer(raw_scalar);
+    let result = point_scalar_multi(&num_point, &num_scalar);
+    std::mem::forget(raw_point);
+    std::mem::forget(raw_scalar);
+    c_write_raw_pointer(&result, output_ciphertext);
+    SUCCESS
+}