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Doug Zongker512536a2010-02-17 16:11:44 -08001/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
Tao Bao97555da2016-12-15 10:15:06 -080017// See imgdiff.cpp in this directory for a description of the patch file
Doug Zongker512536a2010-02-17 16:11:44 -080018// format.
19
Tao Bao97555da2016-12-15 10:15:06 -080020#include <applypatch/imgpatch.h>
21
22#include <errno.h>
Doug Zongker512536a2010-02-17 16:11:44 -080023#include <stdio.h>
Tao Bao97555da2016-12-15 10:15:06 -080024#include <string.h>
Mark Salyzynf3bb31c2014-03-14 09:39:48 -070025#include <sys/cdefs.h>
Doug Zongker512536a2010-02-17 16:11:44 -080026#include <sys/stat.h>
Doug Zongker512536a2010-02-17 16:11:44 -080027#include <unistd.h>
Doug Zongker512536a2010-02-17 16:11:44 -080028
Tianjie Xuaced5d92016-10-12 10:55:04 -070029#include <string>
Yabin Cuid483c202016-02-03 17:08:52 -080030#include <vector>
31
Tao Bao97555da2016-12-15 10:15:06 -080032#include <applypatch/applypatch.h>
33#include <applypatch/imgdiff.h>
34#include <openssl/sha.h>
35#include <zlib.h>
36
Doug Zongker512536a2010-02-17 16:11:44 -080037#include "utils.h"
38
Sen Jiang0cce9cd2016-01-22 20:49:07 +080039int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
40 const unsigned char* patch_data, ssize_t patch_size,
41 SinkFn sink, void* token) {
Tao Bao97555da2016-12-15 10:15:06 -080042 Value patch(VAL_BLOB, std::string(reinterpret_cast<const char*>(patch_data), patch_size));
Tianjie Xuaced5d92016-10-12 10:55:04 -070043
Tao Bao97555da2016-12-15 10:15:06 -080044 return ApplyImagePatch(old_data, old_size, &patch, sink, token, nullptr, nullptr);
Sen Jiang0cce9cd2016-01-22 20:49:07 +080045}
46
Doug Zongker512536a2010-02-17 16:11:44 -080047/*
48 * Apply the patch given in 'patch_filename' to the source data given
49 * by (old_data, old_size). Write the patched output to the 'output'
50 * file, and update the SHA context with the output data as well.
51 * Return 0 on success.
52 */
Tao Bao97555da2016-12-15 10:15:06 -080053int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value* patch,
54 SinkFn sink, void* token, SHA_CTX* ctx, const Value* bonus_data) {
55 if (patch->data.size() < 12) {
56 printf("patch too short to contain header\n");
57 return -1;
58 }
59
60 // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
61 // (IMGDIFF1, which is no longer supported, used CHUNK_NORMAL and
62 // CHUNK_GZIP.)
63 size_t pos = 12;
64 const char* header = &patch->data[0];
65 if (memcmp(header, "IMGDIFF2", 8) != 0) {
66 printf("corrupt patch file header (magic number)\n");
67 return -1;
68 }
69
70 int num_chunks = Read4(header + 8);
71
72 for (int i = 0; i < num_chunks; ++i) {
73 // each chunk's header record starts with 4 bytes.
74 if (pos + 4 > patch->data.size()) {
75 printf("failed to read chunk %d record\n", i);
76 return -1;
77 }
78 int type = Read4(&patch->data[pos]);
79 pos += 4;
80
81 if (type == CHUNK_NORMAL) {
82 const char* normal_header = &patch->data[pos];
83 pos += 24;
84 if (pos > patch->data.size()) {
85 printf("failed to read chunk %d normal header data\n", i);
Doug Zongkerc4351c72010-02-22 14:46:32 -080086 return -1;
Tao Bao97555da2016-12-15 10:15:06 -080087 }
Doug Zongker512536a2010-02-17 16:11:44 -080088
Tao Bao97555da2016-12-15 10:15:06 -080089 size_t src_start = Read8(normal_header);
90 size_t src_len = Read8(normal_header + 8);
91 size_t patch_offset = Read8(normal_header + 16);
92
93 if (src_start + src_len > static_cast<size_t>(old_size)) {
94 printf("source data too short\n");
Doug Zongker512536a2010-02-17 16:11:44 -080095 return -1;
Tao Bao97555da2016-12-15 10:15:06 -080096 }
97 ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, token, ctx);
98 } else if (type == CHUNK_RAW) {
99 const char* raw_header = &patch->data[pos];
100 pos += 4;
101 if (pos > patch->data.size()) {
102 printf("failed to read chunk %d raw header data\n", i);
103 return -1;
104 }
Doug Zongker512536a2010-02-17 16:11:44 -0800105
Tao Bao97555da2016-12-15 10:15:06 -0800106 ssize_t data_len = Read4(raw_header);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800107
Tao Bao97555da2016-12-15 10:15:06 -0800108 if (pos + data_len > patch->data.size()) {
109 printf("failed to read chunk %d raw data\n", i);
110 return -1;
111 }
112 if (ctx) SHA1_Update(ctx, &patch->data[pos], data_len);
113 if (sink(reinterpret_cast<const unsigned char*>(&patch->data[pos]), data_len, token) !=
114 data_len) {
115 printf("failed to write chunk %d raw data\n", i);
116 return -1;
117 }
118 pos += data_len;
119 } else if (type == CHUNK_DEFLATE) {
120 // deflate chunks have an additional 60 bytes in their chunk header.
121 const char* deflate_header = &patch->data[pos];
122 pos += 60;
123 if (pos > patch->data.size()) {
124 printf("failed to read chunk %d deflate header data\n", i);
125 return -1;
126 }
127
128 size_t src_start = Read8(deflate_header);
129 size_t src_len = Read8(deflate_header + 8);
130 size_t patch_offset = Read8(deflate_header + 16);
131 size_t expanded_len = Read8(deflate_header + 24);
132 size_t target_len = Read8(deflate_header + 32);
133 int level = Read4(deflate_header + 40);
134 int method = Read4(deflate_header + 44);
135 int windowBits = Read4(deflate_header + 48);
136 int memLevel = Read4(deflate_header + 52);
137 int strategy = Read4(deflate_header + 56);
138
139 if (src_start + src_len > static_cast<size_t>(old_size)) {
140 printf("source data too short\n");
141 return -1;
142 }
143
144 // Decompress the source data; the chunk header tells us exactly
145 // how big we expect it to be when decompressed.
146
147 // Note: expanded_len will include the bonus data size if
148 // the patch was constructed with bonus data. The
149 // deflation will come up 'bonus_size' bytes short; these
150 // must be appended from the bonus_data value.
151 size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->data.size() : 0;
152
153 std::vector<unsigned char> expanded_source(expanded_len);
154
155 // inflate() doesn't like strm.next_out being a nullptr even with
156 // avail_out being zero (Z_STREAM_ERROR).
157 if (expanded_len != 0) {
158 z_stream strm;
159 strm.zalloc = Z_NULL;
160 strm.zfree = Z_NULL;
161 strm.opaque = Z_NULL;
162 strm.avail_in = src_len;
163 strm.next_in = const_cast<unsigned char*>(old_data + src_start);
164 strm.avail_out = expanded_len;
165 strm.next_out = expanded_source.data();
166
167 int ret = inflateInit2(&strm, -15);
168 if (ret != Z_OK) {
169 printf("failed to init source inflation: %d\n", ret);
170 return -1;
Doug Zongkerc4351c72010-02-22 14:46:32 -0800171 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800172
Tao Bao97555da2016-12-15 10:15:06 -0800173 // Because we've provided enough room to accommodate the output
174 // data, we expect one call to inflate() to suffice.
175 ret = inflate(&strm, Z_SYNC_FLUSH);
176 if (ret != Z_STREAM_END) {
177 printf("source inflation returned %d\n", ret);
178 return -1;
Doug Zongkerc4351c72010-02-22 14:46:32 -0800179 }
Tao Bao97555da2016-12-15 10:15:06 -0800180 // We should have filled the output buffer exactly, except
181 // for the bonus_size.
182 if (strm.avail_out != bonus_size) {
183 printf("source inflation short by %zu bytes\n", strm.avail_out - bonus_size);
184 return -1;
185 }
186 inflateEnd(&strm);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800187
Tao Bao97555da2016-12-15 10:15:06 -0800188 if (bonus_size) {
189 memcpy(expanded_source.data() + (expanded_len - bonus_size), &bonus_data->data[0],
190 bonus_size);
191 }
192 }
193
194 // Next, apply the bsdiff patch (in memory) to the uncompressed data.
195 std::vector<unsigned char> uncompressed_target_data;
196 if (ApplyBSDiffPatchMem(expanded_source.data(), expanded_len, patch, patch_offset,
197 &uncompressed_target_data) != 0) {
198 return -1;
199 }
200 if (uncompressed_target_data.size() != target_len) {
201 printf("expected target len to be %zu, but it's %zu\n", target_len,
202 uncompressed_target_data.size());
203 return -1;
204 }
205
206 // Now compress the target data and append it to the output.
207
208 // we're done with the expanded_source data buffer, so we'll
209 // reuse that memory to receive the output of deflate.
210 if (expanded_source.size() < 32768U) {
211 expanded_source.resize(32768U);
212 }
213
214 {
215 std::vector<unsigned char>& temp_data = expanded_source;
216
217 // now the deflate stream
218 z_stream strm;
219 strm.zalloc = Z_NULL;
220 strm.zfree = Z_NULL;
221 strm.opaque = Z_NULL;
222 strm.avail_in = uncompressed_target_data.size();
223 strm.next_in = uncompressed_target_data.data();
224 int ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
225 if (ret != Z_OK) {
226 printf("failed to init uncompressed data deflation: %d\n", ret);
227 return -1;
228 }
229 do {
230 strm.avail_out = temp_data.size();
231 strm.next_out = temp_data.data();
232 ret = deflate(&strm, Z_FINISH);
233 ssize_t have = temp_data.size() - strm.avail_out;
234
235 if (sink(temp_data.data(), have, token) != have) {
236 printf("failed to write %zd compressed bytes to output\n", have);
237 return -1;
238 }
239 if (ctx) SHA1_Update(ctx, temp_data.data(), have);
240 } while (ret != Z_STREAM_END);
241 deflateEnd(&strm);
242 }
243 } else {
244 printf("patch chunk %d is unknown type %d\n", i, type);
245 return -1;
246 }
247 }
248
249 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800250}