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