[Assignment-7] App Intermediary and Proxy

- Intermediary is fully functional
- Proxy is ready until invocation of enclave

7-SGX_Hands-on/src/app/proxy.c

@@ -4,15 +4,13 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "enclave.h"
+#include "../enclave/enclave.h"
 #include "proxy.h"
 #include "util.h"
 
 sgx_enclave_id_t global_eid = 0;
 
 struct ProxyArgs {
-    char* input_path;
-    char* output_path;
     char* sealed_key_file_path;
     char* sgx_token_path;
 };
@@ -127,26 +125,28 @@ static int initialize_enclave(char* token_path) {
     sgx_status_t ret;
     int updated = 0;
 
-    sgx_token_file = fopen(token_path, "r");
+    sgx_token_file = fopen(token_path, "rb");
     if(sgx_token_file == NULL){
         perror("Error opening sgx token file");
         exit(1);
     }
 
+    //TODO create new on error / ignore missing token file
+
     size_t read_num = fread(token, 1, sizeof(sgx_launch_token_t), sgx_token_file);
     if (read_num != 0 && read_num != sizeof(sgx_launch_token_t)) {
         fprintf(stderr, "sgx token file is corrupted");
         return (1);
     }
 
-   ret = sgx_create_enclave("enclave.so", SGX_DEBUG_FLAG, &token, &updated, &global_eid, NULL);
+   ret = sgx_create_enclave("enclave.signed.so", SGX_DEBUG_FLAG, &token, &updated, &global_eid, NULL);
     if (ret != SGX_SUCCESS) {
         print_error_message(ret);
         return (1);
     }
 
     if (updated) {
-        sgx_token_file = freopen(token_path, "w", sgx_token_file);
+        sgx_token_file = freopen(token_path, "wb", sgx_token_file);
         if(sgx_token_file == NULL){
             perror("Error opening sgx token file");
             return (1);
@@ -163,32 +163,32 @@ static int initialize_enclave(char* token_path) {
 char* proxy_syntax(void) {
     return
         "proxy           implementation of the enclave-powered SignatureProxy\n"
-        "    -i <path>   file path to the intermediary output(signature of firmware)\n"
-        "    -o <path>   output path of the signature\n"
+        "                expects intermediary signature on stdin\n"
+        "                outputs proxied signature on stdout\n"
         "    -s <path>   file path of the sealed proxy key\n"
         "    -t <path>   file path of the sgx token\n";
 }
 
 int handle_proxy(int argc, char** argv) {
     struct ProxyArgs args = {
-        NULL,
-        NULL,
         NULL,
         NULL
     };
-    FILE* input_file;
-    FILE* output_file;
+    FILE* input_file = stdin;
+    FILE* output_file = stdout;
     FILE* sealed_key_file;
+    uint8_t *sealed;
+    uint32_t sealed_size;
+    char line[141];
+    uint8_t signature[70];
+
+    /*
+     * Parse Input
+     */
 
     int i = 0;
     while(i < argc) {
-        if(strcmp(argv[i], "-i")==0 && argc-i >=2){
-            args.input_path = argv[i+1];
-            i += 2;
-        }else if(strcmp(argv[i], "-o")==0 && argc-i >=2){
-            args.output_path = argv[i+1];
-            i += 2;
-        }else if(strcmp(argv[i], "-s")==0 && argc-i >=2){
+        if(strcmp(argv[i], "-s")==0 && argc-i >=2){
             args.sealed_key_file_path = argv[i+1];
             i += 2;
         }else if(strcmp(argv[i], "-t")==0 && argc-i >=2){
@@ -198,25 +198,28 @@ int handle_proxy(int argc, char** argv) {
             syntax_exit();
     }
 
-    if(args.input_path == NULL || args.output_path == NULL || args.sealed_key_file_path == NULL || args.sgx_token_path == NULL)
+    if(args.sealed_key_file_path == NULL || args.sgx_token_path == NULL)
         syntax_exit();
 
-    input_file = fopen(args.input_path, "r");
-    if(input_file == NULL){
-        perror("Error opening input file");
+    if(fgets(line, 141, stdin) == NULL) {
+        fprintf(stderr, "failed to read signature from stdin");
         exit(1);
     }
 
-    output_file = fopen(args.output_path, "w");
-    if(output_file == NULL){
-        perror("Error opening output file");
+    if(line[140] != '\0') {
+        fprintf(stderr, "invalid input");
         exit(1);
     }
 
-    //TODO read input -> calculate size of input (ECDSA of SHA3-256 of Firmware File, generated by intermediary)
-    //TODO read sealed key -> calculate size or dynamic alloc
+    for (i = 0; i < 70; i++) {
+        sscanf(line+2*i, "%02x", &signature[i]);
+    }
 
-    sealed_key_file = fopen(args.sealed_key_file_path, "w");
+    /*
+     * Initialize SGX Enclave
+     */
+
+    sealed_key_file = fopen(args.sealed_key_file_path, "rb");
     if(sealed_key_file == NULL){
         perror("Error opening sealed_key_file file");
         exit(1);
@@ -225,11 +228,20 @@ int handle_proxy(int argc, char** argv) {
     if (initialize_enclave(args.sgx_token_path) != 0)
         exit(1);
 
-    //TODO call enclave -> refactor interface to do verify and sign in one call to avoid trip through "untrusted" land.
+    sealed_size = get_sealed_size();
+    sealed = malloc(sizeof(uint8_t)*sealed_size);
+    if (sealed == NULL) {
+        fprintf(stderr, "failed to allocate for sealed key");
+        exit(1);
+    }
+
+    //TODO load sealed (what to do when missing?)
+
+    //TODO call enclave
 
     //TODO store sealed key if changed
     //TODO write output
+    //TODO enclave teardown
 
-    printf("proxy %s %s", args.input_path, args.output_path);
     exit(0);
 }