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Doug Zongker512536a2010-02-17 16:11:44 -08001/*
2 * Copyright (C) 2008 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
17// This file is a nearly line-for-line copy of bspatch.c from the
18// bsdiff-4.3 distribution; the primary differences being how the
19// input and output data are read and the error handling. Running
20// applypatch with the -l option will display the bsdiff license
21// notice.
22
23#include <stdio.h>
24#include <sys/stat.h>
25#include <errno.h>
26#include <unistd.h>
27#include <string.h>
28
29#include <bzlib.h>
30
31#include "mincrypt/sha.h"
32#include "applypatch.h"
33
34void ShowBSDiffLicense() {
Doug Zongkerc4351c72010-02-22 14:46:32 -080035 puts("The bsdiff library used herein is:\n"
36 "\n"
37 "Copyright 2003-2005 Colin Percival\n"
38 "All rights reserved\n"
39 "\n"
40 "Redistribution and use in source and binary forms, with or without\n"
41 "modification, are permitted providing that the following conditions\n"
42 "are met:\n"
43 "1. Redistributions of source code must retain the above copyright\n"
44 " notice, this list of conditions and the following disclaimer.\n"
45 "2. Redistributions in binary form must reproduce the above copyright\n"
46 " notice, this list of conditions and the following disclaimer in the\n"
47 " documentation and/or other materials provided with the distribution.\n"
48 "\n"
49 "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
50 "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED\n"
51 "WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n"
52 "ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY\n"
53 "DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n"
54 "DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n"
55 "OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n"
56 "HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,\n"
57 "STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING\n"
58 "IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\n"
59 "POSSIBILITY OF SUCH DAMAGE.\n"
60 "\n------------------\n\n"
61 "This program uses Julian R Seward's \"libbzip2\" library, available\n"
62 "from http://www.bzip.org/.\n"
63 );
Doug Zongker512536a2010-02-17 16:11:44 -080064}
65
66static off_t offtin(u_char *buf)
67{
Doug Zongkerc4351c72010-02-22 14:46:32 -080068 off_t y;
Doug Zongker512536a2010-02-17 16:11:44 -080069
Doug Zongkerc4351c72010-02-22 14:46:32 -080070 y=buf[7]&0x7F;
71 y=y*256;y+=buf[6];
72 y=y*256;y+=buf[5];
73 y=y*256;y+=buf[4];
74 y=y*256;y+=buf[3];
75 y=y*256;y+=buf[2];
76 y=y*256;y+=buf[1];
77 y=y*256;y+=buf[0];
Doug Zongker512536a2010-02-17 16:11:44 -080078
Doug Zongkerc4351c72010-02-22 14:46:32 -080079 if(buf[7]&0x80) y=-y;
Doug Zongker512536a2010-02-17 16:11:44 -080080
Doug Zongkerc4351c72010-02-22 14:46:32 -080081 return y;
Doug Zongker512536a2010-02-17 16:11:44 -080082}
83
Doug Zongkerc4351c72010-02-22 14:46:32 -080084int FillBuffer(unsigned char* buffer, int size, bz_stream* stream) {
85 stream->next_out = (char*)buffer;
86 stream->avail_out = size;
87 while (stream->avail_out > 0) {
88 int bzerr = BZ2_bzDecompress(stream);
89 if (bzerr != BZ_OK && bzerr != BZ_STREAM_END) {
90 printf("bz error %d decompressing\n", bzerr);
91 return -1;
92 }
93 if (stream->avail_out > 0) {
94 printf("need %d more bytes\n", stream->avail_out);
95 }
96 }
97 return 0;
98}
Doug Zongker512536a2010-02-17 16:11:44 -080099
100int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
Doug Zongkerc4351c72010-02-22 14:46:32 -0800101 const Value* patch, ssize_t patch_offset,
Doug Zongker512536a2010-02-17 16:11:44 -0800102 SinkFn sink, void* token, SHA_CTX* ctx) {
103
Doug Zongkerc4351c72010-02-22 14:46:32 -0800104 unsigned char* new_data;
105 ssize_t new_size;
106 if (ApplyBSDiffPatchMem(old_data, old_size, patch, patch_offset,
107 &new_data, &new_size) != 0) {
108 return -1;
109 }
Doug Zongker512536a2010-02-17 16:11:44 -0800110
Doug Zongkerc4351c72010-02-22 14:46:32 -0800111 if (sink(new_data, new_size, token) < new_size) {
112 printf("short write of output: %d (%s)\n", errno, strerror(errno));
113 return 1;
114 }
Doug Zongker66f5ce32014-08-15 14:31:52 -0700115 if (ctx) SHA_update(ctx, new_data, new_size);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800116 free(new_data);
Doug Zongker512536a2010-02-17 16:11:44 -0800117
Doug Zongkerc4351c72010-02-22 14:46:32 -0800118 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800119}
120
121int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
Doug Zongkerc4351c72010-02-22 14:46:32 -0800122 const Value* patch, ssize_t patch_offset,
Doug Zongker512536a2010-02-17 16:11:44 -0800123 unsigned char** new_data, ssize_t* new_size) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800124 // Patch data format:
125 // 0 8 "BSDIFF40"
126 // 8 8 X
127 // 16 8 Y
128 // 24 8 sizeof(newfile)
129 // 32 X bzip2(control block)
130 // 32+X Y bzip2(diff block)
131 // 32+X+Y ??? bzip2(extra block)
132 // with control block a set of triples (x,y,z) meaning "add x bytes
133 // from oldfile to x bytes from the diff block; copy y bytes from the
134 // extra block; seek forwards in oldfile by z bytes".
Doug Zongker512536a2010-02-17 16:11:44 -0800135
Doug Zongkerc4351c72010-02-22 14:46:32 -0800136 unsigned char* header = (unsigned char*) patch->data + patch_offset;
137 if (memcmp(header, "BSDIFF40", 8) != 0) {
138 printf("corrupt bsdiff patch file header (magic number)\n");
Doug Zongker512536a2010-02-17 16:11:44 -0800139 return 1;
Doug Zongker512536a2010-02-17 16:11:44 -0800140 }
141
Doug Zongkerc4351c72010-02-22 14:46:32 -0800142 ssize_t ctrl_len, data_len;
143 ctrl_len = offtin(header+8);
144 data_len = offtin(header+16);
145 *new_size = offtin(header+24);
146
147 if (ctrl_len < 0 || data_len < 0 || *new_size < 0) {
148 printf("corrupt patch file header (data lengths)\n");
149 return 1;
Doug Zongker512536a2010-02-17 16:11:44 -0800150 }
151
Doug Zongkerc4351c72010-02-22 14:46:32 -0800152 int bzerr;
153
154 bz_stream cstream;
155 cstream.next_in = patch->data + patch_offset + 32;
156 cstream.avail_in = ctrl_len;
157 cstream.bzalloc = NULL;
158 cstream.bzfree = NULL;
159 cstream.opaque = NULL;
160 if ((bzerr = BZ2_bzDecompressInit(&cstream, 0, 0)) != BZ_OK) {
161 printf("failed to bzinit control stream (%d)\n", bzerr);
Doug Zongker512536a2010-02-17 16:11:44 -0800162 }
163
Doug Zongkerc4351c72010-02-22 14:46:32 -0800164 bz_stream dstream;
165 dstream.next_in = patch->data + patch_offset + 32 + ctrl_len;
166 dstream.avail_in = data_len;
167 dstream.bzalloc = NULL;
168 dstream.bzfree = NULL;
169 dstream.opaque = NULL;
170 if ((bzerr = BZ2_bzDecompressInit(&dstream, 0, 0)) != BZ_OK) {
171 printf("failed to bzinit diff stream (%d)\n", bzerr);
Doug Zongker512536a2010-02-17 16:11:44 -0800172 }
173
Doug Zongkerc4351c72010-02-22 14:46:32 -0800174 bz_stream estream;
175 estream.next_in = patch->data + patch_offset + 32 + ctrl_len + data_len;
176 estream.avail_in = patch->size - (patch_offset + 32 + ctrl_len + data_len);
177 estream.bzalloc = NULL;
178 estream.bzfree = NULL;
179 estream.opaque = NULL;
180 if ((bzerr = BZ2_bzDecompressInit(&estream, 0, 0)) != BZ_OK) {
181 printf("failed to bzinit extra stream (%d)\n", bzerr);
Doug Zongker512536a2010-02-17 16:11:44 -0800182 }
183
Doug Zongkerc4351c72010-02-22 14:46:32 -0800184 *new_data = malloc(*new_size);
185 if (*new_data == NULL) {
186 printf("failed to allocate %ld bytes of memory for output file\n",
187 (long)*new_size);
188 return 1;
Doug Zongker512536a2010-02-17 16:11:44 -0800189 }
190
Doug Zongkerc4351c72010-02-22 14:46:32 -0800191 off_t oldpos = 0, newpos = 0;
192 off_t ctrl[3];
193 off_t len_read;
194 int i;
195 unsigned char buf[24];
196 while (newpos < *new_size) {
197 // Read control data
198 if (FillBuffer(buf, 24, &cstream) != 0) {
199 printf("error while reading control stream\n");
200 return 1;
201 }
202 ctrl[0] = offtin(buf);
203 ctrl[1] = offtin(buf+8);
204 ctrl[2] = offtin(buf+16);
Doug Zongker512536a2010-02-17 16:11:44 -0800205
Doug Zongker4aa12dd2014-05-13 08:40:49 -0700206 if (ctrl[0] < 0 || ctrl[1] < 0) {
207 printf("corrupt patch (negative byte counts)\n");
208 return 1;
209 }
210
Doug Zongkerc4351c72010-02-22 14:46:32 -0800211 // Sanity check
212 if (newpos + ctrl[0] > *new_size) {
213 printf("corrupt patch (new file overrun)\n");
214 return 1;
215 }
Doug Zongker512536a2010-02-17 16:11:44 -0800216
Doug Zongkerc4351c72010-02-22 14:46:32 -0800217 // Read diff string
218 if (FillBuffer(*new_data + newpos, ctrl[0], &dstream) != 0) {
219 printf("error while reading diff stream\n");
220 return 1;
221 }
222
223 // Add old data to diff string
224 for (i = 0; i < ctrl[0]; ++i) {
225 if ((oldpos+i >= 0) && (oldpos+i < old_size)) {
226 (*new_data)[newpos+i] += old_data[oldpos+i];
227 }
228 }
229
230 // Adjust pointers
231 newpos += ctrl[0];
232 oldpos += ctrl[0];
233
234 // Sanity check
235 if (newpos + ctrl[1] > *new_size) {
236 printf("corrupt patch (new file overrun)\n");
237 return 1;
238 }
239
240 // Read extra string
241 if (FillBuffer(*new_data + newpos, ctrl[1], &estream) != 0) {
242 printf("error while reading extra stream\n");
243 return 1;
244 }
245
246 // Adjust pointers
247 newpos += ctrl[1];
248 oldpos += ctrl[2];
249 }
250
251 BZ2_bzDecompressEnd(&cstream);
252 BZ2_bzDecompressEnd(&dstream);
253 BZ2_bzDecompressEnd(&estream);
254 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800255}