applypatch/imgpatch.cpp - platform/bootable/recovery - Git at Google

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 // See imgdiff.cpp in this directory for a description of the patch file
 // format.

 #include <applypatch/imgpatch.h>

 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/cdefs.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include <memory>
 #include <string>
 #include <vector>

 #include <android-base/logging.h>
 #include <android-base/memory.h>
 #include <applypatch/applypatch.h>
 #include <applypatch/imgdiff.h>
 #include <openssl/sha.h>
 #include <zlib.h>

 #include "edify/expr.h"
 #include "otautil/print_sha1.h"

 static inline int64_t Read8(const void *address) {
   return android::base::get_unaligned<int64_t>(address);
 }

 static inline int32_t Read4(const void *address) {
   return android::base::get_unaligned<int32_t>(address);
 }

 // This function is a wrapper of ApplyBSDiffPatch(). It has a custom sink function to deflate the
 // patched data and stream the deflated data to output.
 static bool ApplyBSDiffPatchAndStreamOutput(const uint8_t* src_data, size_t src_len,
                                             const Value& patch, size_t patch_offset,
                                             const char* deflate_header, SinkFn sink) {
   size_t expected_target_length = static_cast<size_t>(Read8(deflate_header + 32));
   CHECK_GT(expected_target_length, static_cast<size_t>(0));
   int level = Read4(deflate_header + 40);
   int method = Read4(deflate_header + 44);
   int window_bits = Read4(deflate_header + 48);
   int mem_level = Read4(deflate_header + 52);
   int strategy = Read4(deflate_header + 56);

   z_stream strm;
   strm.zalloc = Z_NULL;
   strm.zfree = Z_NULL;
   strm.opaque = Z_NULL;
   strm.avail_in = 0;
   strm.next_in = nullptr;
   int ret = deflateInit2(&strm, level, method, window_bits, mem_level, strategy);
   if (ret != Z_OK) {
     LOG(ERROR) << "Failed to init uncompressed data deflation: " << ret;
     return false;
   }

   // Define a custom sink wrapper that feeds to bspatch. It deflates the available patch data on
   // the fly and outputs the compressed data to the given sink.
   size_t actual_target_length = 0;
   size_t total_written = 0;
   static constexpr size_t buffer_size = 32768;
   auto compression_sink = [&strm, &actual_target_length, &expected_target_length, &total_written,
                            &ret, &sink](const uint8_t* data, size_t len) -> size_t {
     // The input patch length for an update never exceeds INT_MAX.
     strm.avail_in = len;
     strm.next_in = data;
     do {
       std::vector<uint8_t> buffer(buffer_size);
       strm.avail_out = buffer_size;
       strm.next_out = buffer.data();
       if (actual_target_length + len < expected_target_length) {
         ret = deflate(&strm, Z_NO_FLUSH);
       } else {
         ret = deflate(&strm, Z_FINISH);
       }
       if (ret != Z_OK && ret != Z_STREAM_END) {
         LOG(ERROR) << "Failed to deflate stream: " << ret;
         // zero length indicates an error in the sink function of bspatch().
         return 0;
       }

       size_t have = buffer_size - strm.avail_out;
       total_written += have;
       if (sink(buffer.data(), have) != have) {
         LOG(ERROR) << "Failed to write " << have << " compressed bytes to output.";
         return 0;
       }
     } while ((strm.avail_in != 0 || strm.avail_out == 0) && ret != Z_STREAM_END);

     actual_target_length += len;
     return len;
   };

   int bspatch_result = ApplyBSDiffPatch(src_data, src_len, patch, patch_offset, compression_sink);
   deflateEnd(&strm);

   if (bspatch_result != 0) {
     return false;
   }

   if (ret != Z_STREAM_END) {
     LOG(ERROR) << "ret is expected to be Z_STREAM_END, but it's " << ret;
     return false;
   }

   if (expected_target_length != actual_target_length) {
     LOG(ERROR) << "target length is expected to be " << expected_target_length << ", but it's "
                << actual_target_length;
     return false;
   }
   LOG(DEBUG) << "bspatch wrote " << total_written << " bytes in total to streaming output.";

   return true;
 }

 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
                     size_t patch_size, SinkFn sink) {
   Value patch(Value::Type::BLOB,
               std::string(reinterpret_cast<const char*>(patch_data), patch_size));
   return ApplyImagePatch(old_data, old_size, patch, sink, nullptr);
 }

 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value& patch, SinkFn sink,
                     const Value* bonus_data) {
   if (patch.data.size() < 12) {
     printf("patch too short to contain header\n");
     return -1;
   }

   // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW. (IMGDIFF1, which is no longer
   // supported, used CHUNK_NORMAL and CHUNK_GZIP.)
   const char* const patch_header = patch.data.data();
   if (memcmp(patch_header, "IMGDIFF2", 8) != 0) {
     printf("corrupt patch file header (magic number)\n");
     return -1;
   }

   int num_chunks = Read4(patch_header + 8);
   size_t pos = 12;
   for (int i = 0; i < num_chunks; ++i) {
     // each chunk's header record starts with 4 bytes.
     if (pos + 4 > patch.data.size()) {
       printf("failed to read chunk %d record\n", i);
       return -1;
     }
     int type = Read4(patch_header + pos);
     pos += 4;

     if (type == CHUNK_NORMAL) {
       const char* normal_header = patch_header + pos;
       pos += 24;
       if (pos > patch.data.size()) {
         printf("failed to read chunk %d normal header data\n", i);
         return -1;
       }

       size_t src_start = static_cast<size_t>(Read8(normal_header));
       size_t src_len = static_cast<size_t>(Read8(normal_header + 8));
       size_t patch_offset = static_cast<size_t>(Read8(normal_header + 16));

       if (src_start + src_len > old_size) {
         printf("source data too short\n");
         return -1;
       }
       if (ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink) != 0) {
         printf("Failed to apply bsdiff patch.\n");
         return -1;
       }

       LOG(DEBUG) << "Processed chunk type normal";
     } else if (type == CHUNK_RAW) {
       const char* raw_header = patch_header + pos;
       pos += 4;
       if (pos > patch.data.size()) {
         printf("failed to read chunk %d raw header data\n", i);
         return -1;
       }

       size_t data_len = static_cast<size_t>(Read4(raw_header));

       if (pos + data_len > patch.data.size()) {
         printf("failed to read chunk %d raw data\n", i);
         return -1;
       }
       if (sink(reinterpret_cast<const unsigned char*>(patch_header + pos), data_len) != data_len) {
         printf("failed to write chunk %d raw data\n", i);
         return -1;
       }
       pos += data_len;

       LOG(DEBUG) << "Processed chunk type raw";
     } else if (type == CHUNK_DEFLATE) {
       // deflate chunks have an additional 60 bytes in their chunk header.
       const char* deflate_header = patch_header + pos;
       pos += 60;
       if (pos > patch.data.size()) {
         printf("failed to read chunk %d deflate header data\n", i);
         return -1;
       }

       size_t src_start = static_cast<size_t>(Read8(deflate_header));
       size_t src_len = static_cast<size_t>(Read8(deflate_header + 8));
       size_t patch_offset = static_cast<size_t>(Read8(deflate_header + 16));
       size_t expanded_len = static_cast<size_t>(Read8(deflate_header + 24));

       if (src_start + src_len > old_size) {
         printf("source data too short\n");
         return -1;
       }

       // Decompress the source data; the chunk header tells us exactly
       // how big we expect it to be when decompressed.

       // Note: expanded_len will include the bonus data size if the patch was constructed with
       // bonus data. The deflation will come up 'bonus_size' bytes short; these must be appended
       // from the bonus_data value.
       size_t bonus_size = (i == 1 && bonus_data != nullptr) ? bonus_data->data.size() : 0;

       std::vector<unsigned char> expanded_source(expanded_len);

       // inflate() doesn't like strm.next_out being a nullptr even with
       // avail_out being zero (Z_STREAM_ERROR).
       if (expanded_len != 0) {
         z_stream strm;
         strm.zalloc = Z_NULL;
         strm.zfree = Z_NULL;
         strm.opaque = Z_NULL;
         strm.avail_in = src_len;
         strm.next_in = old_data + src_start;
         strm.avail_out = expanded_len;
         strm.next_out = expanded_source.data();

         int ret = inflateInit2(&strm, -15);
         if (ret != Z_OK) {
           printf("failed to init source inflation: %d\n", ret);
           return -1;
         }

         // Because we've provided enough room to accommodate the output
         // data, we expect one call to inflate() to suffice.
         ret = inflate(&strm, Z_SYNC_FLUSH);
         if (ret != Z_STREAM_END) {
           printf("source inflation returned %d\n", ret);
           return -1;
         }
         // We should have filled the output buffer exactly, except
         // for the bonus_size.
         if (strm.avail_out != bonus_size) {
           printf("source inflation short by %zu bytes\n", strm.avail_out - bonus_size);
           return -1;
         }
         inflateEnd(&strm);

         if (bonus_size) {
           memcpy(expanded_source.data() + (expanded_len - bonus_size), bonus_data->data.data(),
                  bonus_size);
         }
       }

       if (!ApplyBSDiffPatchAndStreamOutput(expanded_source.data(), expanded_len, patch,
                                            patch_offset, deflate_header, sink)) {
         LOG(ERROR) << "Fail to apply streaming bspatch.";
         return -1;
       }

       LOG(DEBUG) << "Processed chunk type deflate";
     } else {
       printf("patch chunk %d is unknown type %d\n", i, type);
       return -1;
     }
   }

   return 0;
 }
	/*
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	// See imgdiff.cpp in this directory for a description of the patch file
	// format.

	#include <applypatch/imgpatch.h>

	#include <errno.h>
	#include <stdio.h>
	#include <string.h>
	#include <sys/cdefs.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include <memory>
	#include <string>
	#include <vector>

	#include <android-base/logging.h>
	#include <android-base/memory.h>
	#include <applypatch/applypatch.h>
	#include <applypatch/imgdiff.h>
	#include <openssl/sha.h>
	#include <zlib.h>

	#include "edify/expr.h"
	#include "otautil/print_sha1.h"

	static inline int64_t Read8(const void *address) {
	return android::base::get_unaligned<int64_t>(address);
	}

	static inline int32_t Read4(const void *address) {
	return android::base::get_unaligned<int32_t>(address);
	}

	// This function is a wrapper of ApplyBSDiffPatch(). It has a custom sink function to deflate the
	// patched data and stream the deflated data to output.
	static bool ApplyBSDiffPatchAndStreamOutput(const uint8_t* src_data, size_t src_len,
	const Value& patch, size_t patch_offset,
	const char* deflate_header, SinkFn sink) {
	size_t expected_target_length = static_cast<size_t>(Read8(deflate_header + 32));
	CHECK_GT(expected_target_length, static_cast<size_t>(0));
	int level = Read4(deflate_header + 40);
	int method = Read4(deflate_header + 44);
	int window_bits = Read4(deflate_header + 48);
	int mem_level = Read4(deflate_header + 52);
	int strategy = Read4(deflate_header + 56);

	z_stream strm;
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = 0;
	strm.next_in = nullptr;
	int ret = deflateInit2(&strm, level, method, window_bits, mem_level, strategy);
	if (ret != Z_OK) {
	LOG(ERROR) << "Failed to init uncompressed data deflation: " << ret;
	return false;
	}

	// Define a custom sink wrapper that feeds to bspatch. It deflates the available patch data on
	// the fly and outputs the compressed data to the given sink.
	size_t actual_target_length = 0;
	size_t total_written = 0;
	static constexpr size_t buffer_size = 32768;
	auto compression_sink = [&strm, &actual_target_length, &expected_target_length, &total_written,
	&ret, &sink](const uint8_t* data, size_t len) -> size_t {
	// The input patch length for an update never exceeds INT_MAX.
	strm.avail_in = len;
	strm.next_in = data;
	do {
	std::vector<uint8_t> buffer(buffer_size);
	strm.avail_out = buffer_size;
	strm.next_out = buffer.data();
	if (actual_target_length + len < expected_target_length) {
	ret = deflate(&strm, Z_NO_FLUSH);
	} else {
	ret = deflate(&strm, Z_FINISH);
	}
	if (ret != Z_OK && ret != Z_STREAM_END) {
	LOG(ERROR) << "Failed to deflate stream: " << ret;
	// zero length indicates an error in the sink function of bspatch().
	return 0;
	}

	size_t have = buffer_size - strm.avail_out;
	total_written += have;
	if (sink(buffer.data(), have) != have) {
	LOG(ERROR) << "Failed to write " << have << " compressed bytes to output.";
	return 0;
	}
	} while ((strm.avail_in != 0 \|\| strm.avail_out == 0) && ret != Z_STREAM_END);

	actual_target_length += len;
	return len;
	};

	int bspatch_result = ApplyBSDiffPatch(src_data, src_len, patch, patch_offset, compression_sink);
	deflateEnd(&strm);

	if (bspatch_result != 0) {
	return false;
	}

	if (ret != Z_STREAM_END) {
	LOG(ERROR) << "ret is expected to be Z_STREAM_END, but it's " << ret;
	return false;
	}

	if (expected_target_length != actual_target_length) {
	LOG(ERROR) << "target length is expected to be " << expected_target_length << ", but it's "
	<< actual_target_length;
	return false;
	}
	LOG(DEBUG) << "bspatch wrote " << total_written << " bytes in total to streaming output.";

	return true;
	}

	int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
	size_t patch_size, SinkFn sink) {
	Value patch(Value::Type::BLOB,
	std::string(reinterpret_cast<const char*>(patch_data), patch_size));
	return ApplyImagePatch(old_data, old_size, patch, sink, nullptr);
	}

	int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value& patch, SinkFn sink,
	const Value* bonus_data) {
	if (patch.data.size() < 12) {
	printf("patch too short to contain header\n");
	return -1;
	}

	// IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW. (IMGDIFF1, which is no longer
	// supported, used CHUNK_NORMAL and CHUNK_GZIP.)
	const char* const patch_header = patch.data.data();
	if (memcmp(patch_header, "IMGDIFF2", 8) != 0) {
	printf("corrupt patch file header (magic number)\n");
	return -1;
	}

	int num_chunks = Read4(patch_header + 8);
	size_t pos = 12;
	for (int i = 0; i < num_chunks; ++i) {
	// each chunk's header record starts with 4 bytes.
	if (pos + 4 > patch.data.size()) {
	printf("failed to read chunk %d record\n", i);
	return -1;
	}
	int type = Read4(patch_header + pos);
	pos += 4;

	if (type == CHUNK_NORMAL) {
	const char* normal_header = patch_header + pos;
	pos += 24;
	if (pos > patch.data.size()) {
	printf("failed to read chunk %d normal header data\n", i);
	return -1;
	}

	size_t src_start = static_cast<size_t>(Read8(normal_header));
	size_t src_len = static_cast<size_t>(Read8(normal_header + 8));
	size_t patch_offset = static_cast<size_t>(Read8(normal_header + 16));

	if (src_start + src_len > old_size) {
	printf("source data too short\n");
	return -1;
	}
	if (ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink) != 0) {
	printf("Failed to apply bsdiff patch.\n");
	return -1;
	}

	LOG(DEBUG) << "Processed chunk type normal";
	} else if (type == CHUNK_RAW) {
	const char* raw_header = patch_header + pos;
	pos += 4;
	if (pos > patch.data.size()) {
	printf("failed to read chunk %d raw header data\n", i);
	return -1;
	}

	size_t data_len = static_cast<size_t>(Read4(raw_header));

	if (pos + data_len > patch.data.size()) {
	printf("failed to read chunk %d raw data\n", i);
	return -1;
	}
	if (sink(reinterpret_cast<const unsigned char*>(patch_header + pos), data_len) != data_len) {
	printf("failed to write chunk %d raw data\n", i);
	return -1;
	}
	pos += data_len;

	LOG(DEBUG) << "Processed chunk type raw";
	} else if (type == CHUNK_DEFLATE) {
	// deflate chunks have an additional 60 bytes in their chunk header.
	const char* deflate_header = patch_header + pos;
	pos += 60;
	if (pos > patch.data.size()) {
	printf("failed to read chunk %d deflate header data\n", i);
	return -1;
	}

	size_t src_start = static_cast<size_t>(Read8(deflate_header));
	size_t src_len = static_cast<size_t>(Read8(deflate_header + 8));
	size_t patch_offset = static_cast<size_t>(Read8(deflate_header + 16));
	size_t expanded_len = static_cast<size_t>(Read8(deflate_header + 24));

	if (src_start + src_len > old_size) {
	printf("source data too short\n");
	return -1;
	}

	// Decompress the source data; the chunk header tells us exactly
	// how big we expect it to be when decompressed.

	// Note: expanded_len will include the bonus data size if the patch was constructed with
	// bonus data. The deflation will come up 'bonus_size' bytes short; these must be appended
	// from the bonus_data value.
	size_t bonus_size = (i == 1 && bonus_data != nullptr) ? bonus_data->data.size() : 0;

	std::vector<unsigned char> expanded_source(expanded_len);

	// inflate() doesn't like strm.next_out being a nullptr even with
	// avail_out being zero (Z_STREAM_ERROR).
	if (expanded_len != 0) {
	z_stream strm;
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = src_len;
	strm.next_in = old_data + src_start;
	strm.avail_out = expanded_len;
	strm.next_out = expanded_source.data();

	int ret = inflateInit2(&strm, -15);
	if (ret != Z_OK) {
	printf("failed to init source inflation: %d\n", ret);
	return -1;
	}

	// Because we've provided enough room to accommodate the output
	// data, we expect one call to inflate() to suffice.
	ret = inflate(&strm, Z_SYNC_FLUSH);
	if (ret != Z_STREAM_END) {
	printf("source inflation returned %d\n", ret);
	return -1;
	}
	// We should have filled the output buffer exactly, except
	// for the bonus_size.
	if (strm.avail_out != bonus_size) {
	printf("source inflation short by %zu bytes\n", strm.avail_out - bonus_size);
	return -1;
	}
	inflateEnd(&strm);

	if (bonus_size) {
	memcpy(expanded_source.data() + (expanded_len - bonus_size), bonus_data->data.data(),
	bonus_size);
	}
	}

	if (!ApplyBSDiffPatchAndStreamOutput(expanded_source.data(), expanded_len, patch,
	patch_offset, deflate_header, sink)) {
	LOG(ERROR) << "Fail to apply streaming bspatch.";
	return -1;
	}

	LOG(DEBUG) << "Processed chunk type deflate";
	} else {
	printf("patch chunk %d is unknown type %d\n", i, type);
	return -1;
	}
	}

	return 0;
	}