Merge fs.mitm and set.mitm.

stratosphere/ams_mitm/source/fs_mitm/fsmitm_boot0storage.cpp

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2018 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+ 
+#include <switch.h>
+#include <cstring>
+#include <stratosphere.hpp>
+
+#include "fsmitm_boot0storage.hpp"
+
+static HosMutex g_boot0_mutex;
+static u8 g_boot0_bct_buffer[Boot0Storage::BctEndOffset];
+
+bool Boot0Storage::CanModifyBctPubks() {
+    return this->title_id != 0x010000000000001FULL;
+}
+
+Result Boot0Storage::Read(void *_buffer, size_t size, u64 offset) {
+    std::scoped_lock<HosMutex> lk{g_boot0_mutex};
+            
+    return Base::Read(_buffer, size, offset);
+}
+
+Result Boot0Storage::Write(void *_buffer, size_t size, u64 offset) {
+    std::scoped_lock<HosMutex> lk{g_boot0_mutex};
+    
+    Result rc = 0;
+    u8 *buffer = static_cast<u8 *>(_buffer);
+    
+    /* Protect the keyblob region from writes. */
+    if (offset <= EksStart) {
+        if (offset + size < EksStart) {
+            /* Fall through, no need to do anything here. */
+        } else {
+            if (offset + size < EksEnd) {
+                /* Adjust size to avoid writing end of data. */
+                size = EksStart - offset;
+            } else {
+                /* Perform portion of write falling past end of keyblobs. */
+                const u64 diff = EksEnd - offset;
+                if (R_FAILED((rc = Base::Write(buffer + diff, size - diff, EksEnd)))) {
+                    return rc;
+                }
+                /* Adjust size to avoid writing end of data. */
+                size = EksStart - offset;
+            }
+        }
+    } else {
+        if (offset < EksEnd) {
+            if (offset + size < EksEnd) {
+                /* Ignore writes falling strictly within the region. */
+                return 0;
+            } else {
+                /* Only write past the end of the keyblob region. */
+                buffer = buffer + (EksEnd - offset);
+                size -= (EksEnd - offset);
+                offset = EksEnd;
+            }
+        } else {
+            /* Fall through, no need to do anything here. */
+        }
+    }
+    
+    if (size == 0) {
+        return 0;
+    }
+    
+    /* We care about protecting autorcm from NS. */
+    if (CanModifyBctPubks() || offset >= BctEndOffset || (offset + BctSize >= BctEndOffset && offset % BctSize >= BctPubkEnd)) {
+        return Base::Write(buffer, size, offset);
+    }
+    
+    /* First, let's deal with the data past the end. */
+    if (offset + size >= BctEndOffset) {
+        const u64 diff = BctEndOffset - offset;
+        if (R_FAILED((rc = ProxyStorage::Write(buffer + diff, size - diff, BctEndOffset)))) {
+            return rc;
+        }
+        size = diff;
+    }
+    
+    /* Read in the current BCT region. */
+    if (R_FAILED((rc = ProxyStorage::Read(g_boot0_bct_buffer, BctEndOffset, 0)))) {
+        return rc;
+    }
+    
+    /* Update the bct buffer. */
+    for (u64 cur_ofs = offset; cur_ofs < BctEndOffset && cur_ofs < offset + size; cur_ofs++) {
+        const u64 cur_bct_rel_ofs = cur_ofs % BctSize;
+        if (cur_bct_rel_ofs < BctPubkStart || BctPubkEnd <= cur_bct_rel_ofs) {
+            g_boot0_bct_buffer[cur_ofs] = buffer[cur_ofs - offset];
+        }
+    }
+            
+    return ProxyStorage::Write(g_boot0_bct_buffer, BctEndOffset, 0);
+}