Add platformio library definition and C++ compatibility

README.md

@@ -20,7 +20,13 @@ a single pair of c & h file. Deployment options:
 
 - Download [release from Github](https://github.com/DavyLandman/compact25519/releases) 
   and copy into your project directory
-- TODO: Use PlatformIO and take a dependency on compact25519
+
+## Usage with PlatformIO
+
+To use this library in a platformio project, add this to `platformio.ini`:
+
+    lib_deps =
+        compact25519=https://github.com/DavyLandman/compact25519
 
 ## License and origins
 The implementation of the X25519 and Ed25519 is extracted from 
@@ -38,4 +44,4 @@ operations to reduce binary size.
 |----|----|
 | `COMPACT_DISABLE_ED25519` | Disable Ed25519 feature and the related code, shaves of 32% |
 | `COMPACT_DISABLE_X25519` | Disable X25519 feature and the related code, shaves of 25% |
-| `COMPACT_DISABLE_X25519_DERIVE` | Disable custom derive secret feature, extra useful combined with `COMPACT_DISABLE_ED25519`, in itself only saves 3%, combined with disabling Ed25519: 45%|
+| `COMPACT_DISABLE_X25519_DERIVE` | Disable custom derive secret feature, extra useful combined with `COMPACT_DISABLE_ED25519`, in itself only saves 3%, combined with disabling Ed25519: 45%|

algamize.sh

@@ -60,9 +60,14 @@ function make_everything_static() {
 }
 
 function add_decl_spec() {
+    # Add COMPACT_25519_DECL prefix to:
+    # - static functions
+    # - other lines that don't start with space, #, {, }, / or s
+    # - but not to line extern "C"
     sed \
         -e 's/^static /static COMPACT_25519_DECL /' \
-        -e 's/^\([^\ \t#{}()\/*s]\)/COMPACT_25519_DECL \1/' # non static stuff like global header
+        -e 's/^\([^\ \t#{}()\/*s]\)/COMPACT_25519_DECL \1/' \
+        -e 's/COMPACT_25519_DECL\s*\(extern "C" {\)/\1/'
 }
 
 echo "// compact25519 $VERSION
@@ -73,9 +78,6 @@ echo "// compact25519 $VERSION
 
 #ifndef __COMPACT_25519_H
 #define __COMPACT_25519_H
-#if defined(__cplusplus)
-extern \"C\" {
-#endif
 
 // provide your own decl specificier like "-DCOMPACT_25519_DECL=ICACHE_RAM_ATTR"
 #ifndef COMPACT_25519_DECL
@@ -87,10 +89,7 @@ for h in "${COMPACT_FILES[@]}"; do
     cat "$SRC_DIR/$h.h" | remove_header_guard 
 done | merge_includes | remove_double_blank_lines | add_decl_spec >> "$DST_HEADER" 
 
-echo "#if defined(__cplusplus)
-}
-#endif
-#endif" >> "$DST_HEADER"
+echo "#endif" >> "$DST_HEADER"
 
 
 echo "// compact25519 $VERSION
@@ -123,4 +122,4 @@ for h in "${COMPACT_FILES[@]}"; do
     cat "$SRC_DIR/$h.c" | remove_local_imports | \
     remove_double_blank_lines | add_decl_spec
     echo "// ******* END:   $h.c ********"
-done >> "$DST_SOURCE"
+done >> "$DST_SOURCE"

library.json

@@ -0,0 +1,16 @@
+{
+    "name": "compact25519",
+    "version": "1.1.0",
+    "repository": { "type": "git", "url": "https://github.com/DavyLandman/compact25519"},
+    "authors": [
+        { "name": "Daniel Beer", "email": "dlbeer@gmail.com" },
+        { "name": "Davy Landman", "email": "davy.landman@gmail.com" }
+    ],
+    "license": "CC0-1.0",
+    "frameworks": "*",
+    "platforms": "*",
+    "build": {
+        "srcDir": "src",
+        "includeDir": "src"
+    }
+}

src/compact_ed25519.h

@@ -25,6 +25,10 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define ED25519_SEED_SIZE (32)
 #define ED25519_PUBLIC_KEY_SIZE (32)
 #define ED25519_PRIVATE_KEY_SIZE (64)
@@ -105,6 +109,11 @@ bool compact_ed25519_verify(
     const void *message, 
     size_t msg_length
 );
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif
 
 #endif

src/compact_wipe.h

@@ -2,6 +2,11 @@
 #define __COMPACT_WIPE_H
 #include <stdint.h>
 #include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
     Try to wipe contents of a buffer, as best as we can.
     (memset can be ignored by the compiler)
@@ -11,4 +16,9 @@
     returns the data pointer, makes for easier chaining
 */
 void *compact_wipe(void *data, size_t length);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif

src/compact_x25519.h

@@ -26,6 +26,10 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define X25519_KEY_SIZE (32)
 #define X25519_SHARED_SIZE (32)
 
@@ -96,6 +100,11 @@ void compact_x25519_derive_encryption_key(
     const uint8_t public_key1[X25519_KEY_SIZE], 
     const uint8_t public_key2[X25519_KEY_SIZE]
 );
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif
 #endif
 #endif