From df40cc6970c2e50a571405c9750242c9e34b0ab1 Mon Sep 17 00:00:00 2001
From: Gregor Haas <gregorhaas1997@gmail.com>
Date: Mon, 24 Feb 2020 16:17:01 -0500
Subject: [PATCH] some bugfixes and changes for a longer term experiment

---
 c8_remote/lib/payload/src/aes_sw.c | 11 +++--
 c8_remote/main.c                   | 73 ++++++++++++++++++------------
 2 files changed, 50 insertions(+), 34 deletions(-)

diff --git a/c8_remote/lib/payload/src/aes_sw.c b/c8_remote/lib/payload/src/aes_sw.c
index 13e3058..a307d03 100644
--- a/c8_remote/lib/payload/src/aes_sw.c
+++ b/c8_remote/lib/payload/src/aes_sw.c
@@ -173,6 +173,7 @@ void entry_async(uint64_t *base)
 
     expand_key(key, key_sched, 11, sbox, rc_lookup);
 
+    // initialize events and buffers
     struct aes_sw_bernstein_data *data = (struct aes_sw_bernstein_data *) base;
     event_new(&data->ev_data, 1, 0);
     event_new(&data->ev_done, 1, 0);
@@ -180,7 +181,7 @@ void entry_async(uint64_t *base)
     data->count = 0;
     for(i = 0; i < 16; i++)
     {
-        for(j = 0; j < 16; j++)
+        for(j = 0; j < 256; j++)
         {
             data->t[i][j] = 0;
             data->tsq[i][j] = 0;
@@ -190,17 +191,16 @@ void entry_async(uint64_t *base)
 
     while(1)
     {
+        // randomly generate a new msg based on the old one
         for(i = 0; i < 16; i++)
             msg_old[i] = msg[i];
 
-        for(addr = sbox; addr < sbox + 256; addr += 64)
-            inv_va(addr);
-
-
+        // encrypt it and measure time
         start = get_ticks();
         aes128_encrypt_ecb(msg, msg_len, key, sbox, key_sched, mul2, mul3);
         timing = (double) (get_ticks() - start);
 
+        // update counters
         for(i = 0; i < 16; i++)
         {
             data->t[i][msg_old[i]] += timing;
@@ -211,6 +211,7 @@ void entry_async(uint64_t *base)
             data->ttotal += timing;
         }
 
+        // check if host has requested data
         iter_count++;
         if(iter_count % 100000 == 0)
         {
diff --git a/c8_remote/main.c b/c8_remote/main.c
index fb853ca..5013fbd 100644
--- a/c8_remote/main.c
+++ b/c8_remote/main.c
@@ -490,7 +490,7 @@ void usb_task_exit(struct pwned_device *dev)
 int main()
 {
     struct dev_cmd_resp *resp;
-    struct aes_sw_bernstein_data *data;
+    struct aes_sw_bernstein_data data;
     struct pwned_device *dev = exploit_device();
     DEV_PTR_T addr_async_buf;
 
@@ -499,6 +499,9 @@ int main()
     double udev[16][256];
     double taverage;
 
+    FILE *outfile;
+    char linebuf[256];
+
     if(dev == NULL || dev->status == DEV_NORMAL)
     {
         printf("Failed to exploit device\n");
@@ -517,7 +520,7 @@ int main()
 
     while(1)
     {
-        sleep(15);
+        sleep(60);
         if(IS_CHECKM8_FAIL(open_device_session(dev)))
         {
             printf("failed to open device session");
@@ -542,34 +545,9 @@ int main()
             return -1;
         }
 
-        data = (struct aes_sw_bernstein_data *) resp->data;
-        printf("have count %lli\n", data->count);
-
-        taverage = data->ttotal / (double) data->count;
-        for(j = 0; j < 16; j++)
-        {
-            for(b = 0; b < 256; b++)
-            {
-                u[j][b] = data->t[j][b] / data->tnum[j][b];
-                udev[j][b] = data->tsq[j][b] / data->tnum[j][b];
-                udev[j][b] -= u[j][b] * u[j][b];
-                udev[j][b] = sqrt(udev[j][b]);
-            }
-        }
-
-        for(j = 0; j < 16; j++)
-        {
-            for(b = 0; b < 256; b++)
-            {
-                printf("%2d %3d %lli %.3f %.3f %.3f %.3f\n",
-                       j, b, (long long) data->tnum[j][b],
-                       u[j][b], udev[j][b],
-                       u[j][b] - taverage, udev[j][b] / sqrt(data->tnum[j][b])
-                );
-            }
-        }
-
+        memcpy(&data, resp->data, sizeof(struct aes_sw_bernstein_data));
         free_dev_cmd_resp(resp);
+
         resp = execute_gadget(dev, ADDR_EVENT_NOTIFY, 0, 1,
                               addr_async_buf + offsetof(struct aes_sw_bernstein_data, ev_done));
         if(IS_CHECKM8_FAIL(resp->ret))
@@ -585,6 +563,43 @@ int main()
             printf("failed to close device session\n");
             return -1;
         }
+
+        printf("have count %lli\n", data.count);
+        taverage = data.ttotal / (double) data.count;
+
+        for(j = 0; j < 16; j++)
+        {
+            for(b = 0; b < 256; b++)
+            {
+                u[j][b] = data.t[j][b] / data.tnum[j][b];
+                udev[j][b] = data.tsq[j][b] / data.tnum[j][b];
+                udev[j][b] -= u[j][b] * u[j][b];
+                udev[j][b] = sqrt(udev[j][b]);
+            }
+        }
+
+        sprintf(linebuf, "dat_%lli.dat", data.count);
+        outfile = fopen(linebuf, "w+");
+        if(outfile == NULL)
+        {
+            printf("failed to open data file\n");
+            return -1;
+        }
+
+        for(j = 0; j < 16; j++)
+        {
+            for(b = 0; b < 256; b++)
+            {
+                sprintf(linebuf,
+                        "%2d %3d %lli %f %f %f %f\n",
+                        j, b, (long long) data.tnum[j][b],
+                        u[j][b], udev[j][b],
+                        u[j][b] - taverage, udev[j][b] / sqrt(data.tnum[j][b]));
+                fputs(linebuf, outfile);
+            }
+        }
+
+        fclose(outfile);
     }
 
     free_device(dev);