From 8192496116f5f7b71238b6e7d33240fa0de1a96d Mon Sep 17 00:00:00 2001
From: Simon Maddocks <git@51m0n.com>
Date: Tue, 25 Jan 2022 23:01:41 +0000
Subject: [PATCH] Add initial encrypt and dummy decrypt

---
 .gitignore                  |  5 ++
 Romulus-M/CMakeLists.txt    | 14 ++----
 Romulus-M/encrypt_wrapper.c | 97 +++++++++++++++++++++++++++++++++++++
 Romulus-M/encrypt_wrapper.h | 20 ++++++++
 Romulus-M/export.h          |  5 +-
 5 files changed, 126 insertions(+), 15 deletions(-)
 create mode 100644 Romulus-M/encrypt_wrapper.c
 create mode 100644 Romulus-M/encrypt_wrapper.h

diff --git a/.gitignore b/.gitignore
index cd531cf..5e2259c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -52,3 +52,8 @@ Module.symvers
 Mkfile.old
 dkms.conf
 
+
+CMakeFiles
+cmake_install.cmake
+CMakeCache.txt
+Makefile
diff --git a/Romulus-M/CMakeLists.txt b/Romulus-M/CMakeLists.txt
index 2f3c033..8a7555f 100644
--- a/Romulus-M/CMakeLists.txt
+++ b/Romulus-M/CMakeLists.txt
@@ -3,16 +3,8 @@ set(SRC
     encrypt.c
     romulus_m_reference.c
     skinny_reference.c
+    encrypt_wrapper.c
 )
 
-if(EMSCRIPTEN)
-    # WASM requires an executable, so we use a dummy target that doesn't do anything
-    # and link our library into it.
-    add_library(romulus-m STATIC ${SRC})
-    add_executable(romulus-m-wasm "main.c")
-    target_link_libraries(romulus-m-wasm PRIVATE romulus-m)
-    target_link_options(romulus-m-wasm PRIVATE -s EXPORTED_FUNCTIONS=['_main', '_crypto_aead_encrypt', '_crypto_aead_decrypt'])
-else()
-    add_library(romulus-m SHARED ${SRC})
-    install(TARGETS romulus-m)
-endif()
+add_library(romulus-m STATIC ${SRC})
+install(TARGETS romulus-m)
\ No newline at end of file
diff --git a/Romulus-M/encrypt_wrapper.c b/Romulus-M/encrypt_wrapper.c
new file mode 100644
index 0000000..d8fa9c1
--- /dev/null
+++ b/Romulus-M/encrypt_wrapper.c
@@ -0,0 +1,97 @@
+#include "encrypt_wrapper.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <byteswap.h>
+#include <sys/random.h>
+#include "romulus_m.h"
+#include "api.h"
+
+
+int encrypt(packet *packet, unsigned char* outBuf, __uint16_t *len){
+    if(sizeof(u_int16_t) + sizeof(u_int16_t) + packet->Size > *len){
+        return 1;
+    }
+
+    int packetSize = packet->Size;
+
+    packet->DataType = __bswap_16(packet->DataType);   
+
+    // enc
+    // ciphertext - out, MAX 16 bytes larger than plaintext - defined as CRYPTO_ABYTES
+    unsigned long long clen = packetSize + CRYPTO_ABYTES;
+    unsigned char* c = (unsigned char*) calloc(clen, 1);
+        
+    // plaintext - in
+    int mlen = packetSize;
+    unsigned char* m = packet->Data;
+   
+
+    // additional text
+    int adlen = sizeof(packet->DataType);
+    unsigned char* ad = (unsigned char*)&packet->DataType;
+
+    // unused
+    unsigned char* nsec;
+
+    // n = nonce, CRYPTO_NPUBBYTES size 16
+    unsigned char npub[CRYPTO_NPUBBYTES];
+    getrandom(&npub[0], sizeof(npub), 0);
+
+    // key, CRYPTO_KEYBYTES size 16
+    unsigned char k[CRYPTO_KEYBYTES] = {0};
+    romulus_m_encrypt(c, &clen, m, mlen, ad, adlen, 0, &npub[0], &k[0]);
+      
+    if(clen > *len + CRYPTO_NPUBBYTES){
+        free(c);
+        return 1;
+    }
+    
+    // type 0 1
+    int loc = 0;
+    memcpy(&outBuf[loc], &packet->DataType,sizeof(u_int16_t));
+    loc += sizeof(u_int16_t);
+
+    // data size 2 3
+    u_int16_t clen16 = (u_int16_t)clen;
+    // we copy data and nonce
+    clen16 += CRYPTO_NPUBBYTES;
+    clen16 = __bswap_16(clen16);
+    memcpy(&outBuf[loc], &clen16, sizeof(u_int16_t));
+    loc += sizeof(u_int16_t);
+
+    memcpy(&outBuf[loc], npub, CRYPTO_NPUBBYTES);
+    loc += CRYPTO_NPUBBYTES;
+
+    memcpy(&outBuf[loc], c, clen);
+    loc += clen;
+
+    *len = loc;
+
+    free(c);
+
+    return 0;
+}
+
+int decrypt(packetEx *packet, unsigned char* inBuf, __uint16_t len){
+    int loc = 0;
+    memcpy(&packet->DataType, &inBuf[loc], sizeof(u_int16_t));
+    loc += sizeof(u_int16_t);
+    memcpy(&packet->Id, &inBuf[loc], sizeof(u_int32_t));
+    loc += sizeof(u_int32_t);
+    memcpy(&packet->Size, &inBuf[loc], sizeof(u_int16_t));
+    loc += sizeof(u_int16_t);
+
+    packet->DataType = __bswap_16(packet->DataType);
+    packet->Size = __bswap_16(packet->Size);
+    packet->Id = __bswap_32(packet->Id);
+
+    if(packet->Size <= 1000){
+        memcpy(packet->Data, &inBuf[loc], packet->Size);
+    }
+    else{
+        return 1;
+    }
+   
+    return 0;
+}
\ No newline at end of file
diff --git a/Romulus-M/encrypt_wrapper.h b/Romulus-M/encrypt_wrapper.h
new file mode 100644
index 0000000..6f0f8ac
--- /dev/null
+++ b/Romulus-M/encrypt_wrapper.h
@@ -0,0 +1,20 @@
+#include <stdio.h>
+#include "export.h"
+
+typedef struct {
+    __uint16_t DataType;
+    __uint16_t Size;
+    unsigned char* Data;
+}packet;
+
+typedef struct {
+    __uint16_t DataType;
+    __uint32_t Id;
+    __uint16_t Size;
+    unsigned char* Data;
+}packetEx;
+
+EXPORT int encrypt(packet *packet, unsigned char* outBuf, __uint16_t *len);
+
+
+EXPORT int decrypt(packetEx *packet, unsigned char* inBuf, __uint16_t len);
\ No newline at end of file
diff --git a/Romulus-M/export.h b/Romulus-M/export.h
index 3776f2f..92fa7ab 100644
--- a/Romulus-M/export.h
+++ b/Romulus-M/export.h
@@ -8,9 +8,6 @@
 
 #ifdef _WIN32
 #define EXPORT __declspec(dllexport)
-#elif __linux__
+#else
 #define EXPORT __attribute__((visibility("default")))
-#elif __EMSCRIPTEN__
-#include <emscripten.h>
-#define EXPORT EMSCRIPTEN_KEEPALIVE
 #endif