tools/applypatch/imgpatch.c - platform/build - 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.c in this directory for a description of the patch file
 // format.

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

 #include "zlib.h"
 #include "mincrypt/sha.h"
 #include "applypatch.h"
 #include "imgdiff.h"
 #include "utils.h"

 /*
  * Apply the patch given in 'patch_filename' to the source data given
  * by (old_data, old_size).  Write the patched output to the 'output'
  * file, and update the SHA context with the output data as well.
  * Return 0 on success.
  */
 int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
                     const char* patch_filename,
                     SinkFn sink, void* token, SHA_CTX* ctx) {
   FILE* f;
   if ((f = fopen(patch_filename, "rb")) == NULL) {
     fprintf(stderr, "failed to open patch file\n");
     return -1;
   }

   unsigned char header[12];
   if (fread(header, 1, 12, f) != 12) {
     fprintf(stderr, "failed to read patch file header\n");
     return -1;
   }

   // IMGDIFF1 uses CHUNK_NORMAL and CHUNK_GZIP.
   // IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
   if (memcmp(header, "IMGDIFF", 7) != 0 ||
       (header[7] != '1' && header[7] != '2')) {
     fprintf(stderr, "corrupt patch file header (magic number)\n");
     return -1;
   }

   int num_chunks = Read4(header+8);

   int i;
   for (i = 0; i < num_chunks; ++i) {
     // each chunk's header record starts with 4 bytes.
     unsigned char chunk[4];
     if (fread(chunk, 1, 4, f) != 4) {
       fprintf(stderr, "failed to read chunk %d record\n", i);
       return -1;
     }

     int type = Read4(chunk);

     if (type == CHUNK_NORMAL) {
       unsigned char normal_header[24];
       if (fread(normal_header, 1, 24, f) != 24) {
         fprintf(stderr, "failed to read chunk %d normal header data\n", i);
         return -1;
       }

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

       fprintf(stderr, "CHUNK %d:  normal   patch offset %d\n", i, patch_offset);

       ApplyBSDiffPatch(old_data + src_start, src_len,
                        patch_filename, patch_offset,
                        sink, token, ctx);
     } else if (type == CHUNK_GZIP) {
       // This branch is basically a duplicate of the CHUNK_DEFLATE
       // branch, with a bit of extra processing for the gzip header
       // and footer.  I've avoided factoring the common code out since
       // this branch will just be deleted when we drop support for
       // IMGDIFF1.

       // gzip chunks have an additional 64 + gzip_header_len + 8 bytes
       // in their chunk header.
       unsigned char* gzip = malloc(64);
       if (fread(gzip, 1, 64, f) != 64) {
         fprintf(stderr, "failed to read chunk %d initial gzip header data\n",
                 i);
         return -1;
       }
       size_t gzip_header_len = Read4(gzip+60);
       gzip = realloc(gzip, 64 + gzip_header_len + 8);
       if (fread(gzip+64, 1, gzip_header_len+8, f) != gzip_header_len+8) {
         fprintf(stderr, "failed to read chunk %d remaining gzip header data\n",
                 i);
         return -1;
       }

       size_t src_start = Read8(gzip);
       size_t src_len = Read8(gzip+8);
       size_t patch_offset = Read8(gzip+16);

       size_t expanded_len = Read8(gzip+24);
       size_t target_len = Read8(gzip+32);
       int gz_level = Read4(gzip+40);
       int gz_method = Read4(gzip+44);
       int gz_windowBits = Read4(gzip+48);
       int gz_memLevel = Read4(gzip+52);
       int gz_strategy = Read4(gzip+56);

       fprintf(stderr, "CHUNK %d:  gzip     patch offset %d\n", i, patch_offset);

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

       unsigned char* expanded_source = malloc(expanded_len);
       if (expanded_source == NULL) {
         fprintf(stderr, "failed to allocate %d bytes for expanded_source\n",
                 expanded_len);
         return -1;
       }

       z_stream strm;
       strm.zalloc = Z_NULL;
       strm.zfree = Z_NULL;
       strm.opaque = Z_NULL;
       strm.avail_in = src_len - (gzip_header_len + 8);
       strm.next_in = (unsigned char*)(old_data + src_start + gzip_header_len);
       strm.avail_out = expanded_len;
       strm.next_out = expanded_source;

       int ret;
       ret = inflateInit2(&strm, -15);
       if (ret != Z_OK) {
         fprintf(stderr, "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) {
         fprintf(stderr, "source inflation returned %d\n", ret);
         return -1;
       }
       // We should have filled the output buffer exactly.
       if (strm.avail_out != 0) {
         fprintf(stderr, "source inflation short by %d bytes\n", strm.avail_out);
         return -1;
       }
       inflateEnd(&strm);

       // Next, apply the bsdiff patch (in memory) to the uncompressed
       // data.
       unsigned char* uncompressed_target_data;
       ssize_t uncompressed_target_size;
       if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
                               patch_filename, patch_offset,
                               &uncompressed_target_data,
                               &uncompressed_target_size) != 0) {
         return -1;
       }

       // Now compress the target data and append it to the output.

       // start with the gzip header.
       sink(gzip+64, gzip_header_len, token);
       SHA_update(ctx, gzip+64, gzip_header_len);

       // we're done with the expanded_source data buffer, so we'll
       // reuse that memory to receive the output of deflate.
       unsigned char* temp_data = expanded_source;
       ssize_t temp_size = expanded_len;
       if (temp_size < 32768) {
         // ... unless the buffer is too small, in which case we'll
         // allocate a fresh one.
         free(temp_data);
         temp_data = malloc(32768);
         temp_size = 32768;
       }

       // now the deflate stream
       strm.zalloc = Z_NULL;
       strm.zfree = Z_NULL;
       strm.opaque = Z_NULL;
       strm.avail_in = uncompressed_target_size;
       strm.next_in = uncompressed_target_data;
       ret = deflateInit2(&strm, gz_level, gz_method, gz_windowBits,
                          gz_memLevel, gz_strategy);
       do {
         strm.avail_out = temp_size;
         strm.next_out = temp_data;
         ret = deflate(&strm, Z_FINISH);
         size_t have = temp_size - strm.avail_out;

         if (sink(temp_data, have, token) != have) {
           fprintf(stderr, "failed to write %d compressed bytes to output\n",
                   have);
           return -1;
         }
         SHA_update(ctx, temp_data, have);
       } while (ret != Z_STREAM_END);
       deflateEnd(&strm);

       // lastly, the gzip footer.
       sink(gzip+64+gzip_header_len, 8, token);
       SHA_update(ctx, gzip+64+gzip_header_len, 8);

       free(temp_data);
       free(uncompressed_target_data);
       free(gzip);
     } else if (type == CHUNK_RAW) {
       unsigned char raw_header[4];
       if (fread(raw_header, 1, 4, f) != 4) {
         fprintf(stderr, "failed to read chunk %d raw header data\n", i);
         return -1;
       }

       size_t data_len = Read4(raw_header);

       fprintf(stderr, "CHUNK %d:  raw      data %d\n", i, data_len);

       unsigned char* temp = malloc(data_len);
       if (fread(temp, 1, data_len, f) != data_len) {
           fprintf(stderr, "failed to read chunk %d raw data\n", i);
           return -1;
       }
       SHA_update(ctx, temp, data_len);
       if (sink(temp, data_len, token) != data_len) {
           fprintf(stderr, "failed to write chunk %d raw data\n", i);
           return -1;
       }
     } else if (type == CHUNK_DEFLATE) {
       // deflate chunks have an additional 60 bytes in their chunk header.
       unsigned char deflate_header[60];
       if (fread(deflate_header, 1, 60, f) != 60) {
         fprintf(stderr, "failed to read chunk %d deflate header data\n", i);
         return -1;
       }

       size_t src_start = Read8(deflate_header);
       size_t src_len = Read8(deflate_header+8);
       size_t patch_offset = Read8(deflate_header+16);
       size_t expanded_len = Read8(deflate_header+24);
       size_t target_len = Read8(deflate_header+32);
       int level = Read4(deflate_header+40);
       int method = Read4(deflate_header+44);
       int windowBits = Read4(deflate_header+48);
       int memLevel = Read4(deflate_header+52);
       int strategy = Read4(deflate_header+56);

       fprintf(stderr, "CHUNK %d:  deflate  patch offset %d\n", i, patch_offset);

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

       unsigned char* expanded_source = malloc(expanded_len);
       if (expanded_source == NULL) {
         fprintf(stderr, "failed to allocate %d bytes for expanded_source\n",
                 expanded_len);
         return -1;
       }

       z_stream strm;
       strm.zalloc = Z_NULL;
       strm.zfree = Z_NULL;
       strm.opaque = Z_NULL;
       strm.avail_in = src_len;
       strm.next_in = (unsigned char*)(old_data + src_start);
       strm.avail_out = expanded_len;
       strm.next_out = expanded_source;

       int ret;
       ret = inflateInit2(&strm, -15);
       if (ret != Z_OK) {
         fprintf(stderr, "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) {
         fprintf(stderr, "source inflation returned %d\n", ret);
         return -1;
       }
       // We should have filled the output buffer exactly.
       if (strm.avail_out != 0) {
         fprintf(stderr, "source inflation short by %d bytes\n", strm.avail_out);
         return -1;
       }
       inflateEnd(&strm);

       // Next, apply the bsdiff patch (in memory) to the uncompressed
       // data.
       unsigned char* uncompressed_target_data;
       ssize_t uncompressed_target_size;
       if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
                               patch_filename, patch_offset,
                               &uncompressed_target_data,
                               &uncompressed_target_size) != 0) {
         return -1;
       }

       // Now compress the target data and append it to the output.

       // we're done with the expanded_source data buffer, so we'll
       // reuse that memory to receive the output of deflate.
       unsigned char* temp_data = expanded_source;
       ssize_t temp_size = expanded_len;
       if (temp_size < 32768) {
         // ... unless the buffer is too small, in which case we'll
         // allocate a fresh one.
         free(temp_data);
         temp_data = malloc(32768);
         temp_size = 32768;
       }

       // now the deflate stream
       strm.zalloc = Z_NULL;
       strm.zfree = Z_NULL;
       strm.opaque = Z_NULL;
       strm.avail_in = uncompressed_target_size;
       strm.next_in = uncompressed_target_data;
       ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
       do {
         strm.avail_out = temp_size;
         strm.next_out = temp_data;
         ret = deflate(&strm, Z_FINISH);
         size_t have = temp_size - strm.avail_out;

         if (sink(temp_data, have, token) != have) {
           fprintf(stderr, "failed to write %d compressed bytes to output\n",
                   have);
           return -1;
         }
         SHA_update(ctx, temp_data, have);
       } while (ret != Z_STREAM_END);
       deflateEnd(&strm);

       free(temp_data);
       free(uncompressed_target_data);
     } else {
       fprintf(stderr, "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.c in this directory for a description of the patch file
	// format.

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

	#include "zlib.h"
	#include "mincrypt/sha.h"
	#include "applypatch.h"
	#include "imgdiff.h"
	#include "utils.h"

	/*
	* Apply the patch given in 'patch_filename' to the source data given
	* by (old_data, old_size). Write the patched output to the 'output'
	* file, and update the SHA context with the output data as well.
	* Return 0 on success.
	*/
	int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
	const char* patch_filename,
	SinkFn sink, void* token, SHA_CTX* ctx) {
	FILE* f;
	if ((f = fopen(patch_filename, "rb")) == NULL) {
	fprintf(stderr, "failed to open patch file\n");
	return -1;
	}

	unsigned char header[12];
	if (fread(header, 1, 12, f) != 12) {
	fprintf(stderr, "failed to read patch file header\n");
	return -1;
	}

	// IMGDIFF1 uses CHUNK_NORMAL and CHUNK_GZIP.
	// IMGDIFF2 uses CHUNK_NORMAL, CHUNK_DEFLATE, and CHUNK_RAW.
	if (memcmp(header, "IMGDIFF", 7) != 0 \|\|
	(header[7] != '1' && header[7] != '2')) {
	fprintf(stderr, "corrupt patch file header (magic number)\n");
	return -1;
	}

	int num_chunks = Read4(header+8);

	int i;
	for (i = 0; i < num_chunks; ++i) {
	// each chunk's header record starts with 4 bytes.
	unsigned char chunk[4];
	if (fread(chunk, 1, 4, f) != 4) {
	fprintf(stderr, "failed to read chunk %d record\n", i);
	return -1;
	}

	int type = Read4(chunk);

	if (type == CHUNK_NORMAL) {
	unsigned char normal_header[24];
	if (fread(normal_header, 1, 24, f) != 24) {
	fprintf(stderr, "failed to read chunk %d normal header data\n", i);
	return -1;
	}

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

	fprintf(stderr, "CHUNK %d: normal patch offset %d\n", i, patch_offset);

	ApplyBSDiffPatch(old_data + src_start, src_len,
	patch_filename, patch_offset,
	sink, token, ctx);
	} else if (type == CHUNK_GZIP) {
	// This branch is basically a duplicate of the CHUNK_DEFLATE
	// branch, with a bit of extra processing for the gzip header
	// and footer. I've avoided factoring the common code out since
	// this branch will just be deleted when we drop support for
	// IMGDIFF1.

	// gzip chunks have an additional 64 + gzip_header_len + 8 bytes
	// in their chunk header.
	unsigned char* gzip = malloc(64);
	if (fread(gzip, 1, 64, f) != 64) {
	fprintf(stderr, "failed to read chunk %d initial gzip header data\n",
	i);
	return -1;
	}
	size_t gzip_header_len = Read4(gzip+60);
	gzip = realloc(gzip, 64 + gzip_header_len + 8);
	if (fread(gzip+64, 1, gzip_header_len+8, f) != gzip_header_len+8) {
	fprintf(stderr, "failed to read chunk %d remaining gzip header data\n",
	i);
	return -1;
	}

	size_t src_start = Read8(gzip);
	size_t src_len = Read8(gzip+8);
	size_t patch_offset = Read8(gzip+16);

	size_t expanded_len = Read8(gzip+24);
	size_t target_len = Read8(gzip+32);
	int gz_level = Read4(gzip+40);
	int gz_method = Read4(gzip+44);
	int gz_windowBits = Read4(gzip+48);
	int gz_memLevel = Read4(gzip+52);
	int gz_strategy = Read4(gzip+56);

	fprintf(stderr, "CHUNK %d: gzip patch offset %d\n", i, patch_offset);

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

	unsigned char* expanded_source = malloc(expanded_len);
	if (expanded_source == NULL) {
	fprintf(stderr, "failed to allocate %d bytes for expanded_source\n",
	expanded_len);
	return -1;
	}

	z_stream strm;
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = src_len - (gzip_header_len + 8);
	strm.next_in = (unsigned char*)(old_data + src_start + gzip_header_len);
	strm.avail_out = expanded_len;
	strm.next_out = expanded_source;

	int ret;
	ret = inflateInit2(&strm, -15);
	if (ret != Z_OK) {
	fprintf(stderr, "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) {
	fprintf(stderr, "source inflation returned %d\n", ret);
	return -1;
	}
	// We should have filled the output buffer exactly.
	if (strm.avail_out != 0) {
	fprintf(stderr, "source inflation short by %d bytes\n", strm.avail_out);
	return -1;
	}
	inflateEnd(&strm);

	// Next, apply the bsdiff patch (in memory) to the uncompressed
	// data.
	unsigned char* uncompressed_target_data;
	ssize_t uncompressed_target_size;
	if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
	patch_filename, patch_offset,
	&uncompressed_target_data,
	&uncompressed_target_size) != 0) {
	return -1;
	}

	// Now compress the target data and append it to the output.

	// start with the gzip header.
	sink(gzip+64, gzip_header_len, token);
	SHA_update(ctx, gzip+64, gzip_header_len);

	// we're done with the expanded_source data buffer, so we'll
	// reuse that memory to receive the output of deflate.
	unsigned char* temp_data = expanded_source;
	ssize_t temp_size = expanded_len;
	if (temp_size < 32768) {
	// ... unless the buffer is too small, in which case we'll
	// allocate a fresh one.
	free(temp_data);
	temp_data = malloc(32768);
	temp_size = 32768;
	}

	// now the deflate stream
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = uncompressed_target_size;
	strm.next_in = uncompressed_target_data;
	ret = deflateInit2(&strm, gz_level, gz_method, gz_windowBits,
	gz_memLevel, gz_strategy);
	do {
	strm.avail_out = temp_size;
	strm.next_out = temp_data;
	ret = deflate(&strm, Z_FINISH);
	size_t have = temp_size - strm.avail_out;

	if (sink(temp_data, have, token) != have) {
	fprintf(stderr, "failed to write %d compressed bytes to output\n",
	have);
	return -1;
	}
	SHA_update(ctx, temp_data, have);
	} while (ret != Z_STREAM_END);
	deflateEnd(&strm);

	// lastly, the gzip footer.
	sink(gzip+64+gzip_header_len, 8, token);
	SHA_update(ctx, gzip+64+gzip_header_len, 8);

	free(temp_data);
	free(uncompressed_target_data);
	free(gzip);
	} else if (type == CHUNK_RAW) {
	unsigned char raw_header[4];
	if (fread(raw_header, 1, 4, f) != 4) {
	fprintf(stderr, "failed to read chunk %d raw header data\n", i);
	return -1;
	}

	size_t data_len = Read4(raw_header);

	fprintf(stderr, "CHUNK %d: raw data %d\n", i, data_len);

	unsigned char* temp = malloc(data_len);
	if (fread(temp, 1, data_len, f) != data_len) {
	fprintf(stderr, "failed to read chunk %d raw data\n", i);
	return -1;
	}
	SHA_update(ctx, temp, data_len);
	if (sink(temp, data_len, token) != data_len) {
	fprintf(stderr, "failed to write chunk %d raw data\n", i);
	return -1;
	}
	} else if (type == CHUNK_DEFLATE) {
	// deflate chunks have an additional 60 bytes in their chunk header.
	unsigned char deflate_header[60];
	if (fread(deflate_header, 1, 60, f) != 60) {
	fprintf(stderr, "failed to read chunk %d deflate header data\n", i);
	return -1;
	}

	size_t src_start = Read8(deflate_header);
	size_t src_len = Read8(deflate_header+8);
	size_t patch_offset = Read8(deflate_header+16);
	size_t expanded_len = Read8(deflate_header+24);
	size_t target_len = Read8(deflate_header+32);
	int level = Read4(deflate_header+40);
	int method = Read4(deflate_header+44);
	int windowBits = Read4(deflate_header+48);
	int memLevel = Read4(deflate_header+52);
	int strategy = Read4(deflate_header+56);

	fprintf(stderr, "CHUNK %d: deflate patch offset %d\n", i, patch_offset);

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

	unsigned char* expanded_source = malloc(expanded_len);
	if (expanded_source == NULL) {
	fprintf(stderr, "failed to allocate %d bytes for expanded_source\n",
	expanded_len);
	return -1;
	}

	z_stream strm;
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = src_len;
	strm.next_in = (unsigned char*)(old_data + src_start);
	strm.avail_out = expanded_len;
	strm.next_out = expanded_source;

	int ret;
	ret = inflateInit2(&strm, -15);
	if (ret != Z_OK) {
	fprintf(stderr, "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) {
	fprintf(stderr, "source inflation returned %d\n", ret);
	return -1;
	}
	// We should have filled the output buffer exactly.
	if (strm.avail_out != 0) {
	fprintf(stderr, "source inflation short by %d bytes\n", strm.avail_out);
	return -1;
	}
	inflateEnd(&strm);

	// Next, apply the bsdiff patch (in memory) to the uncompressed
	// data.
	unsigned char* uncompressed_target_data;
	ssize_t uncompressed_target_size;
	if (ApplyBSDiffPatchMem(expanded_source, expanded_len,
	patch_filename, patch_offset,
	&uncompressed_target_data,
	&uncompressed_target_size) != 0) {
	return -1;
	}

	// Now compress the target data and append it to the output.

	// we're done with the expanded_source data buffer, so we'll
	// reuse that memory to receive the output of deflate.
	unsigned char* temp_data = expanded_source;
	ssize_t temp_size = expanded_len;
	if (temp_size < 32768) {
	// ... unless the buffer is too small, in which case we'll
	// allocate a fresh one.
	free(temp_data);
	temp_data = malloc(32768);
	temp_size = 32768;
	}

	// now the deflate stream
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = uncompressed_target_size;
	strm.next_in = uncompressed_target_data;
	ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
	do {
	strm.avail_out = temp_size;
	strm.next_out = temp_data;
	ret = deflate(&strm, Z_FINISH);
	size_t have = temp_size - strm.avail_out;

	if (sink(temp_data, have, token) != have) {
	fprintf(stderr, "failed to write %d compressed bytes to output\n",
	have);
	return -1;
	}
	SHA_update(ctx, temp_data, have);
	} while (ret != Z_STREAM_END);
	deflateEnd(&strm);

	free(temp_data);
	free(uncompressed_target_data);
	} else {
	fprintf(stderr, "patch chunk %d is unknown type %d\n", i, type);
	return -1;
	}
	}

	return 0;
	}