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-rw-r--r--applypatch/bspatch.cpp255
1 files changed, 255 insertions, 0 deletions
diff --git a/applypatch/bspatch.cpp b/applypatch/bspatch.cpp
new file mode 100644
index 000000000..9d201b477
--- /dev/null
+++ b/applypatch/bspatch.cpp
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+// This file is a nearly line-for-line copy of bspatch.c from the
+// bsdiff-4.3 distribution; the primary differences being how the
+// input and output data are read and the error handling. Running
+// applypatch with the -l option will display the bsdiff license
+// notice.
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <bzlib.h>
+
+#include "mincrypt/sha.h"
+#include "applypatch.h"
+
+void ShowBSDiffLicense() {
+ puts("The bsdiff library used herein is:\n"
+ "\n"
+ "Copyright 2003-2005 Colin Percival\n"
+ "All rights reserved\n"
+ "\n"
+ "Redistribution and use in source and binary forms, with or without\n"
+ "modification, are permitted providing that the following conditions\n"
+ "are met:\n"
+ "1. Redistributions of source code must retain the above copyright\n"
+ " notice, this list of conditions and the following disclaimer.\n"
+ "2. Redistributions in binary form must reproduce the above copyright\n"
+ " notice, this list of conditions and the following disclaimer in the\n"
+ " documentation and/or other materials provided with the distribution.\n"
+ "\n"
+ "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
+ "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED\n"
+ "WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n"
+ "ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY\n"
+ "DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n"
+ "DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n"
+ "OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n"
+ "HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,\n"
+ "STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING\n"
+ "IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\n"
+ "POSSIBILITY OF SUCH DAMAGE.\n"
+ "\n------------------\n\n"
+ "This program uses Julian R Seward's \"libbzip2\" library, available\n"
+ "from http://www.bzip.org/.\n"
+ );
+}
+
+static off_t offtin(u_char *buf)
+{
+ off_t y;
+
+ y=buf[7]&0x7F;
+ y=y*256;y+=buf[6];
+ y=y*256;y+=buf[5];
+ y=y*256;y+=buf[4];
+ y=y*256;y+=buf[3];
+ y=y*256;y+=buf[2];
+ y=y*256;y+=buf[1];
+ y=y*256;y+=buf[0];
+
+ if(buf[7]&0x80) y=-y;
+
+ return y;
+}
+
+int FillBuffer(unsigned char* buffer, int size, bz_stream* stream) {
+ stream->next_out = (char*)buffer;
+ stream->avail_out = size;
+ while (stream->avail_out > 0) {
+ int bzerr = BZ2_bzDecompress(stream);
+ if (bzerr != BZ_OK && bzerr != BZ_STREAM_END) {
+ printf("bz error %d decompressing\n", bzerr);
+ return -1;
+ }
+ if (stream->avail_out > 0) {
+ printf("need %d more bytes\n", stream->avail_out);
+ }
+ }
+ return 0;
+}
+
+int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size,
+ const Value* patch, ssize_t patch_offset,
+ SinkFn sink, void* token, SHA_CTX* ctx) {
+
+ unsigned char* new_data;
+ ssize_t new_size;
+ if (ApplyBSDiffPatchMem(old_data, old_size, patch, patch_offset,
+ &new_data, &new_size) != 0) {
+ return -1;
+ }
+
+ if (sink(new_data, new_size, token) < new_size) {
+ printf("short write of output: %d (%s)\n", errno, strerror(errno));
+ return 1;
+ }
+ if (ctx) SHA_update(ctx, new_data, new_size);
+ free(new_data);
+
+ return 0;
+}
+
+int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
+ const Value* patch, ssize_t patch_offset,
+ unsigned char** new_data, ssize_t* new_size) {
+ // Patch data format:
+ // 0 8 "BSDIFF40"
+ // 8 8 X
+ // 16 8 Y
+ // 24 8 sizeof(newfile)
+ // 32 X bzip2(control block)
+ // 32+X Y bzip2(diff block)
+ // 32+X+Y ??? bzip2(extra block)
+ // with control block a set of triples (x,y,z) meaning "add x bytes
+ // from oldfile to x bytes from the diff block; copy y bytes from the
+ // extra block; seek forwards in oldfile by z bytes".
+
+ unsigned char* header = (unsigned char*) patch->data + patch_offset;
+ if (memcmp(header, "BSDIFF40", 8) != 0) {
+ printf("corrupt bsdiff patch file header (magic number)\n");
+ return 1;
+ }
+
+ ssize_t ctrl_len, data_len;
+ ctrl_len = offtin(header+8);
+ data_len = offtin(header+16);
+ *new_size = offtin(header+24);
+
+ if (ctrl_len < 0 || data_len < 0 || *new_size < 0) {
+ printf("corrupt patch file header (data lengths)\n");
+ return 1;
+ }
+
+ int bzerr;
+
+ bz_stream cstream;
+ cstream.next_in = patch->data + patch_offset + 32;
+ cstream.avail_in = ctrl_len;
+ cstream.bzalloc = NULL;
+ cstream.bzfree = NULL;
+ cstream.opaque = NULL;
+ if ((bzerr = BZ2_bzDecompressInit(&cstream, 0, 0)) != BZ_OK) {
+ printf("failed to bzinit control stream (%d)\n", bzerr);
+ }
+
+ bz_stream dstream;
+ dstream.next_in = patch->data + patch_offset + 32 + ctrl_len;
+ dstream.avail_in = data_len;
+ dstream.bzalloc = NULL;
+ dstream.bzfree = NULL;
+ dstream.opaque = NULL;
+ if ((bzerr = BZ2_bzDecompressInit(&dstream, 0, 0)) != BZ_OK) {
+ printf("failed to bzinit diff stream (%d)\n", bzerr);
+ }
+
+ bz_stream estream;
+ estream.next_in = patch->data + patch_offset + 32 + ctrl_len + data_len;
+ estream.avail_in = patch->size - (patch_offset + 32 + ctrl_len + data_len);
+ estream.bzalloc = NULL;
+ estream.bzfree = NULL;
+ estream.opaque = NULL;
+ if ((bzerr = BZ2_bzDecompressInit(&estream, 0, 0)) != BZ_OK) {
+ printf("failed to bzinit extra stream (%d)\n", bzerr);
+ }
+
+ *new_data = reinterpret_cast<unsigned char*>(malloc(*new_size));
+ if (*new_data == NULL) {
+ printf("failed to allocate %zd bytes of memory for output file\n", *new_size);
+ return 1;
+ }
+
+ off_t oldpos = 0, newpos = 0;
+ off_t ctrl[3];
+ off_t len_read;
+ int i;
+ unsigned char buf[24];
+ while (newpos < *new_size) {
+ // Read control data
+ if (FillBuffer(buf, 24, &cstream) != 0) {
+ printf("error while reading control stream\n");
+ return 1;
+ }
+ ctrl[0] = offtin(buf);
+ ctrl[1] = offtin(buf+8);
+ ctrl[2] = offtin(buf+16);
+
+ if (ctrl[0] < 0 || ctrl[1] < 0) {
+ printf("corrupt patch (negative byte counts)\n");
+ return 1;
+ }
+
+ // Sanity check
+ if (newpos + ctrl[0] > *new_size) {
+ printf("corrupt patch (new file overrun)\n");
+ return 1;
+ }
+
+ // Read diff string
+ if (FillBuffer(*new_data + newpos, ctrl[0], &dstream) != 0) {
+ printf("error while reading diff stream\n");
+ return 1;
+ }
+
+ // Add old data to diff string
+ for (i = 0; i < ctrl[0]; ++i) {
+ if ((oldpos+i >= 0) && (oldpos+i < old_size)) {
+ (*new_data)[newpos+i] += old_data[oldpos+i];
+ }
+ }
+
+ // Adjust pointers
+ newpos += ctrl[0];
+ oldpos += ctrl[0];
+
+ // Sanity check
+ if (newpos + ctrl[1] > *new_size) {
+ printf("corrupt patch (new file overrun)\n");
+ return 1;
+ }
+
+ // Read extra string
+ if (FillBuffer(*new_data + newpos, ctrl[1], &estream) != 0) {
+ printf("error while reading extra stream\n");
+ return 1;
+ }
+
+ // Adjust pointers
+ newpos += ctrl[1];
+ oldpos += ctrl[2];
+ }
+
+ BZ2_bzDecompressEnd(&cstream);
+ BZ2_bzDecompressEnd(&dstream);
+ BZ2_bzDecompressEnd(&estream);
+ return 0;
+}
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