AU: Sign delta payloads

delta_diff_generator.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "update_engine/delta_diff_generator.h"
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <algorithm>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 #include <bzlib.h>
 #include "base/logging.h"
 #include "update_engine/bzip.h"
 #include "update_engine/cycle_breaker.h"
 #include "update_engine/extent_mapper.h"
 #include "update_engine/file_writer.h"
 #include "update_engine/filesystem_iterator.h"
 #include "update_engine/graph_types.h"
 #include "update_engine/graph_utils.h"
+#include "update_engine/payload_signer.h"
 #include "update_engine/subprocess.h"
 #include "update_engine/topological_sort.h"
 #include "update_engine/update_metadata.pb.h"
 #include "update_engine/utils.h"
 
 using std::make_pair;
 using std::max;
 using std::min;
 using std::set;
 using std::string;
@@ skipping 51 matching lines @@
 // error messages.
 bool AddInstallOpToBlocksVector(
     const DeltaArchiveManifest_InstallOperation& operation,
     vector<Block>* blocks,
     const Graph& graph,
     Vertex::Index vertex) {
   LOG(INFO) << "AddInstallOpToBlocksVector(" << vertex << "), "
             << graph[vertex].file_name;
   // See if this is already present.
   TEST_AND_RETURN_FALSE(operation.dst_extents_size() > 0);
-  
+
   enum BlockField { READER = 0, WRITER, BLOCK_FIELD_COUNT };
   for (int field = READER; field < BLOCK_FIELD_COUNT; field++) {
     const int extents_size =
         (field == READER) ? operation.src_extents_size() :
         operation.dst_extents_size();
     const char* past_participle = (field == READER) ? "read" : "written";
     const google::protobuf::RepeatedPtrField<Extent>& extents =
         (field == READER) ? operation.src_extents() : operation.dst_extents();
     Vertex::Index Block::*access_type =
         (field == READER) ? &Block::reader : &Block::writer;
@@ skipping 45 matching lines @@
                                                            &operation));
 
   // Write the data
   if (operation.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE) {
     operation.set_data_offset(*data_file_size);
     operation.set_data_length(data.size());
   }
 
   TEST_AND_RETURN_FALSE(utils::WriteAll(data_fd, &data[0], data.size()));
   *data_file_size += data.size();
-  
+
   // Now, insert into graph and blocks vector
   graph->resize(graph->size() + 1);
   graph->back().op = operation;
   CHECK(graph->back().op.has_type());
   graph->back().file_name = path;
-  
+
   TEST_AND_RETURN_FALSE(AddInstallOpToBlocksVector(graph->back().op,
                                                    blocks,
                                                    *graph,
                                                    graph->size() - 1));
   return true;
 }
 
 // For each regular file within new_root, creates a node in the graph,
 // determines the best way to compress it (REPLACE, REPLACE_BZ, COPY, BSDIFF),
 // and writes any necessary data to the end of data_fd.
@@ skipping 11 matching lines @@
       continue;
 
     // Make sure we visit each inode only once.
     if (utils::SetContainsKey(visited_inodes, fs_iter.GetStat().st_ino))
       continue;
     visited_inodes.insert(fs_iter.GetStat().st_ino);
     if (fs_iter.GetStat().st_size == 0)
       continue;
 
     LOG(INFO) << "Encoding file " << fs_iter.GetPartialPath();
-    
+
     TEST_AND_RETURN_FALSE(DeltaReadFile(graph,
                                         blocks,
                                         old_root,
                                         new_root,
                                         fs_iter.GetPartialPath(),
                                         data_fd,
                                         data_file_size));
   }
   return true;
 }
@@ skipping 81 matching lines @@
   ScopedFdCloser image_fd_closer(&image_fd);
 
   string temp_file_path;
   TEST_AND_RETURN_FALSE(utils::MakeTempFile("/tmp/CrAU_temp_data.XXXXXX",
                                             &temp_file_path,
                                             NULL));
 
   FILE* file = fopen(temp_file_path.c_str(), "w");
   TEST_AND_RETURN_FALSE(file);
   int err = BZ_OK;
-  
+
   BZFILE* bz_file = BZ2_bzWriteOpen(&err,
                                     file,
                                     9,  // max compression
                                     0,  // verbosity
                                     0);  // default work factor
   TEST_AND_RETURN_FALSE(err == BZ_OK);
-  
+
   vector<Extent> extents;
   vector<Block>::size_type block_count = 0;
-  
+
   LOG(INFO) << "Appending left over blocks to extents";
   for (vector<Block>::size_type i = 0; i < blocks.size(); i++) {
     if (blocks[i].writer != Vertex::kInvalidIndex)
       continue;
     graph_utils::AppendBlockToExtents(&extents, i);
     block_count++;
   }
 
   // Code will handle 'buf' at any size that's a multiple of kBlockSize,
   // so we arbitrarily set it to 1024 * kBlockSize.
@@ skipping 27 matching lines @@
       blocks_read += copy_block_cnt;
       blocks_copied_count += copy_block_cnt;
       LOG(INFO) << "progress: " << ((float)blocks_copied_count)/block_count;
     }
   }
   BZ2_bzWriteClose(&err, bz_file, 0, NULL, NULL);
   TEST_AND_RETURN_FALSE(err == BZ_OK);
   bz_file = NULL;
   TEST_AND_RETURN_FALSE_ERRNO(0 == fclose(file));
   file = NULL;
-  
+
   vector<char> compressed_data;
   LOG(INFO) << "Reading compressed data off disk";
   TEST_AND_RETURN_FALSE(utils::ReadFile(temp_file_path, &compressed_data));
   TEST_AND_RETURN_FALSE(unlink(temp_file_path.c_str()) == 0);
-  
+
   // Add node to graph to write these blocks
   out_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
   out_op->set_data_offset(*blobs_length);
   out_op->set_data_length(compressed_data.size());
   *blobs_length += compressed_data.size();
   out_op->set_dst_length(kBlockSize * block_count);
   DeltaDiffGenerator::StoreExtents(extents, out_op->mutable_dst_extents());
-  
+
   TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd,
                                         &compressed_data[0],
                                         compressed_data.size()));
   LOG(INFO) << "done with extra blocks";
   return true;
 }
 
 // Writes the uint64_t passed in in host-endian to the file as big-endian.
 // Returns true on success.
 bool WriteUint64AsBigEndian(FileWriter* writer, const uint64_t value) {
@@ skipping 24 matching lines @@
   }
 }
 
 void CheckGraph(const Graph& graph) {
   for (Graph::const_iterator it = graph.begin(); it != graph.end(); ++it) {
     CHECK(it->op.has_type());
   }
 }
 
 // Delta compresses a kernel partition new_kernel_part with knowledge of
-// the old kernel partition old_kernel_part. 
+// the old kernel partition old_kernel_part.
 bool DeltaCompressKernelPartition(
     const string& old_kernel_part,
     const string& new_kernel_part,
     vector<DeltaArchiveManifest_InstallOperation>* ops,
     int blobs_fd,
     off_t* blobs_length) {
   // For now, just bsdiff the kernel partition as a whole.
   // TODO(adlr): Use knowledge of how the kernel partition is laid out
   // to more efficiently compress it.
 
   LOG(INFO) << "Delta compressing kernel partition...";
 
   // Add a new install operation
   ops->resize(1);
   DeltaArchiveManifest_InstallOperation* op = &(*ops)[0];
   op->set_type(DeltaArchiveManifest_InstallOperation_Type_BSDIFF);
   op->set_data_offset(*blobs_length);
 
   // Do the actual compression
   vector<char> data;
   TEST_AND_RETURN_FALSE(BsdiffFiles(old_kernel_part, new_kernel_part, &data));
   TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd, &data[0], data.size()));
   *blobs_length += data.size();
-  
+
   off_t old_part_size = utils::FileSize(old_kernel_part);
   TEST_AND_RETURN_FALSE(old_part_size >= 0);
   off_t new_part_size = utils::FileSize(new_kernel_part);
   TEST_AND_RETURN_FALSE(new_part_size >= 0);
-  
+
   op->set_data_length(data.size());
 
   op->set_src_length(old_part_size);
   op->set_dst_length(new_part_size);
 
   // Theres a single src/dest extent for each
   Extent* src_extent = op->add_src_extents();
   src_extent->set_start_block(0);
   src_extent->set_num_blocks((old_part_size + kBlockSize - 1) / kBlockSize);
 
   Extent* dst_extent = op->add_dst_extents();
   dst_extent->set_start_block(0);
   dst_extent->set_num_blocks((new_part_size + kBlockSize - 1) / kBlockSize);
-  
+
   LOG(INFO) << "Done delta compressing kernel partition.";
   return true;
 }
 
 }  // namespace {}
 
 bool DeltaDiffGenerator::ReadFileToDiff(
     const string& old_filename,
     const string& new_filename,
     vector<char>* out_data,
     DeltaArchiveManifest_InstallOperation* out_op) {
   // Read new data in
   vector<char> new_data;
   TEST_AND_RETURN_FALSE(utils::ReadFile(new_filename, &new_data));
-  
+
   TEST_AND_RETURN_FALSE(!new_data.empty());
-  
+
   vector<char> new_data_bz;
   TEST_AND_RETURN_FALSE(BzipCompress(new_data, &new_data_bz));
   CHECK(!new_data_bz.empty());
 
   vector<char> data;  // Data blob that will be written to delta file.
 
   DeltaArchiveManifest_InstallOperation operation;
   size_t current_best_size = 0;
   if (new_data.size() <= new_data_bz.size()) {
     operation.set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
@@ skipping 21 matching lines @@
       data.clear();
     } else {
       // Try bsdiff of old to new data
       vector<char> bsdiff_delta;
       TEST_AND_RETURN_FALSE(
           BsdiffFiles(old_filename, new_filename, &bsdiff_delta));
       CHECK_GT(bsdiff_delta.size(), 0);
       if (bsdiff_delta.size() < current_best_size) {
         operation.set_type(DeltaArchiveManifest_InstallOperation_Type_BSDIFF);
         current_best_size = bsdiff_delta.size();
-        
+
         data = bsdiff_delta;
       }
     }
   }
-  
+
   // Set parameters of the operations
   CHECK_EQ(data.size(), current_best_size);
-  
+
   if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE ||
       operation.type() == DeltaArchiveManifest_InstallOperation_Type_BSDIFF) {
     TEST_AND_RETURN_FALSE(
         GatherExtents(old_filename, operation.mutable_src_extents()));
     operation.set_src_length(old_stbuf.st_size);
   }
 
   TEST_AND_RETURN_FALSE(
       GatherExtents(new_filename, operation.mutable_dst_extents()));
   operation.set_dst_length(new_data.size());
-  
+
   out_data->swap(data);
   *out_op = operation;
-  
+
   return true;
 }
 
 void DeltaDiffGenerator::SubstituteBlocks(
     DeltaArchiveManifest_InstallOperation* op,
     const vector<Extent>& remove_extents,
     const vector<Extent>& replace_extents) {
   // First, expand out the blocks that op reads from
   vector<uint64_t> read_blocks;
   for (int i = 0; i < op->src_extents_size(); i++) {
@@ skipping 54 matching lines @@
   // First, find enough scratch space for the edges we'll be cutting.
   vector<Block>::size_type blocks_required = 0;
   for (set<Edge>::const_iterator it = edges.begin(); it != edges.end(); ++it) {
     blocks_required += graph_utils::EdgeWeight(*graph, *it);
   }
   vector<Extent> scratch_extents;
   LOG(INFO) << "requesting " << blocks_required << " blocks of scratch";
   TEST_AND_RETURN_FALSE(
       FindScratchSpace(blocks, blocks_required, &scratch_extents));
   LinearExtentAllocator scratch_allocator(scratch_extents);
-  
+
   uint64_t scratch_blocks_used = 0;
   for (set<Edge>::const_iterator it = edges.begin();
        it != edges.end(); ++it) {
     vector<Extent> old_extents =
         (*graph)[it->first].out_edges[it->second].extents;
     // Choose some scratch space
     scratch_blocks_used += graph_utils::EdgeWeight(*graph, *it);
     LOG(INFO) << "using " << graph_utils::EdgeWeight(*graph, *it)
               << " scratch blocks ("
               << scratch_blocks_used << ")";
     vector<Extent> scratch =
         scratch_allocator.Allocate(graph_utils::EdgeWeight(*graph, *it));
     // create vertex to copy original->scratch
     graph->resize(graph->size() + 1);
-    
+
     // make node depend on the copy operation
     (*graph)[it->first].out_edges.insert(make_pair(graph->size() - 1,
                                                    EdgeProperties()));
 
     // Set src/dst extents and other proto variables for copy operation
     graph->back().op.set_type(DeltaArchiveManifest_InstallOperation_Type_MOVE);
     DeltaDiffGenerator::StoreExtents(
         (*graph)[it->first].out_edges[it->second].extents,
         graph->back().op.mutable_src_extents());
     DeltaDiffGenerator::StoreExtents(scratch,
@@ skipping 94 matching lines @@
     out_file_size += buf.size();
   }
   return true;
 }
 
 bool DeltaDiffGenerator::GenerateDeltaUpdateFile(
     const string& old_root,
     const string& old_image,
     const string& new_root,
     const string& new_image,
-    const std::string& old_kernel_part,
-    const std::string& new_kernel_part,
-    const string& output_path) {
+    const string& old_kernel_part,
+    const string& new_kernel_part,
+    const string& output_path,
+    const string& private_key_path) {
   struct stat old_image_stbuf;
   TEST_AND_RETURN_FALSE_ERRNO(stat(old_image.c_str(), &old_image_stbuf) == 0);
   struct stat new_image_stbuf;
   TEST_AND_RETURN_FALSE_ERRNO(stat(new_image.c_str(), &new_image_stbuf) == 0);
   LOG_IF(WARNING, new_image_stbuf.st_size != old_image_stbuf.st_size)
       << "Old and new images are different sizes.";
   LOG_IF(FATAL, new_image_stbuf.st_size % kBlockSize)
       << "New image not a multiple of block size " << kBlockSize;
   LOG_IF(FATAL, old_image_stbuf.st_size % kBlockSize)
       << "Old image not a multiple of block size " << kBlockSize;
 
   // Sanity check kernel partition args
   TEST_AND_RETURN_FALSE(utils::FileSize(old_kernel_part) >= 0);
   TEST_AND_RETURN_FALSE(utils::FileSize(new_kernel_part) >= 0);
 
   vector<Block> blocks(max(old_image_stbuf.st_size / kBlockSize,
                            new_image_stbuf.st_size / kBlockSize));
   LOG(INFO) << "invalid: " << Vertex::kInvalidIndex;
   LOG(INFO) << "len: " << blocks.size();
   for (vector<Block>::size_type i = 0; i < blocks.size(); i++) {
     CHECK(blocks[i].reader == Vertex::kInvalidIndex);
     CHECK(blocks[i].writer == Vertex::kInvalidIndex);
   }
   Graph graph;
   CheckGraph(graph);
-  
+
   const string kTempFileTemplate("/tmp/CrAU_temp_data.XXXXXX");
   string temp_file_path;
   off_t data_file_size = 0;
 
   LOG(INFO) << "Reading files...";
 
   vector<DeltaArchiveManifest_InstallOperation> kernel_ops;
 
   DeltaArchiveManifest_InstallOperation final_op;
   {
     int fd;
     TEST_AND_RETURN_FALSE(
         utils::MakeTempFile(kTempFileTemplate, &temp_file_path, &fd));
     TEST_AND_RETURN_FALSE(fd >= 0);
     ScopedFdCloser fd_closer(&fd);
-  
+
     TEST_AND_RETURN_FALSE(DeltaReadFiles(&graph,
                                          &blocks,
                                          old_root,
                                          new_root,
                                          fd,
                                          &data_file_size));
     CheckGraph(graph);
-                                         
+
     TEST_AND_RETURN_FALSE(ReadUnwrittenBlocks(blocks,
                                               fd,
                                               &data_file_size,
                                               new_image,
-                                              &final_op));  
+                                              &final_op));
 
     // Read kernel partition
     TEST_AND_RETURN_FALSE(DeltaCompressKernelPartition(old_kernel_part,
                                                        new_kernel_part,
                                                        &kernel_ops,
                                                        fd,
                                                        &data_file_size));
   }
   CheckGraph(graph);
-  
+
   LOG(INFO) << "Creating edges...";
   CreateEdges(&graph, blocks);
   CheckGraph(graph);
-  
+
   CycleBreaker cycle_breaker;
   LOG(INFO) << "Finding cycles...";
   set<Edge> cut_edges;
   cycle_breaker.BreakCycles(graph, &cut_edges);
   CheckGraph(graph);
 
   // Calculate number of scratch blocks needed
 
   LOG(INFO) << "Cutting cycles...";
   TEST_AND_RETURN_FALSE(CutEdges(&graph, blocks, cut_edges));
   CheckGraph(graph);
 
   vector<Vertex::Index> final_order;
   LOG(INFO) << "Ordering...";
   TopologicalSort(graph, &final_order);
   CheckGraph(graph);
-  
+
   // Convert to protobuf Manifest object
   DeltaArchiveManifest manifest;
   CheckGraph(graph);
   InstallOperationsToManifest(graph, final_order, kernel_ops, &manifest);
   {
     // Write final operation
     DeltaArchiveManifest_InstallOperation* op =
         manifest.add_install_operations();
     *op = final_op;
     CHECK(op->has_type());
     LOG(INFO) << "final op length: " << op->data_length();
   }
-  
+
   CheckGraph(graph);
   manifest.set_block_size(kBlockSize);
 
   // Reorder the data blobs with the newly ordered manifest
   string ordered_blobs_path;
   TEST_AND_RETURN_FALSE(utils::MakeTempFile(
       "/tmp/CrAU_temp_data.ordered.XXXXXX",
       &ordered_blobs_path,
       false));
   TEST_AND_RETURN_FALSE(ReorderDataBlobs(&manifest,
                                          temp_file_path,
                                          ordered_blobs_path));
 
   // Check that install op blobs are in order and that all blocks are written.
+  uint64_t next_blob_offset = 0;
   {
     vector<uint32_t> written_count(blocks.size(), 0);
-    uint64_t next_blob_offset = 0;
     for (int i = 0; i < (manifest.install_operations_size() +
                          manifest.kernel_install_operations_size()); i++) {
-      const DeltaArchiveManifest_InstallOperation& op =
+      DeltaArchiveManifest_InstallOperation* op =
           i < manifest.install_operations_size() ?
-          manifest.install_operations(i) :
-          manifest.kernel_install_operations(
+          manifest.mutable_install_operations(i) :
+          manifest.mutable_kernel_install_operations(
               i - manifest.install_operations_size());
-      for (int j = 0; j < op.dst_extents_size(); j++) {
-        const Extent& extent = op.dst_extents(j);
+      for (int j = 0; j < op->dst_extents_size(); j++) {
+        const Extent& extent = op->dst_extents(j);
         for (uint64_t block = extent.start_block();
              block < (extent.start_block() + extent.num_blocks()); block++) {
           written_count[block]++;
         }
       }
-      if (op.has_data_offset()) {
-        if (op.data_offset() != next_blob_offset) {
-          LOG(FATAL) << "bad blob offset! " << op.data_offset() << " != "
+      if (op->has_data_offset()) {
+        if (op->data_offset() != next_blob_offset) {
+          LOG(FATAL) << "bad blob offset! " << op->data_offset() << " != "
                      << next_blob_offset;
         }
-        next_blob_offset += op.data_length();
+        next_blob_offset += op->data_length();
       }
     }
     // check all blocks written to
     for (vector<uint32_t>::size_type i = 0; i < written_count.size(); i++) {
       if (written_count[i] == 0) {
         LOG(FATAL) << "block " << i << " not written!";
       }
     }
   }
 
+  // Signatures appear at the end of the blobs. Note the offset in the
+  // manifest
+  if (!private_key_path.empty()) {
+    LOG(INFO) << "Making room for signature in file";
+    manifest.set_signatures_offset(next_blob_offset);
+    LOG(INFO) << "set? " << manifest.has_signatures_offset();
+    // Add a dummy op at the end to appease older clients
+    DeltaArchiveManifest_InstallOperation* dummy_op =
+        manifest.add_kernel_install_operations();
+    dummy_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
+    dummy_op->set_data_offset(next_blob_offset);
+    manifest.set_signatures_offset(next_blob_offset);
+    uint64_t signature_blob_length = 0;
+    TEST_AND_RETURN_FALSE(
+        PayloadSigner::SignatureBlobLength(private_key_path,
+                                           &signature_blob_length));
+    dummy_op->set_data_length(signature_blob_length);
+    manifest.set_signatures_size(signature_blob_length);
+    Extent* dummy_extent = dummy_op->add_dst_extents();
+    // Tell the dummy op to write this data to a big sparse hole
+    dummy_extent->set_start_block(kSparseHole);
+    dummy_extent->set_num_blocks((signature_blob_length + kBlockSize - 1) /
+                                 kBlockSize);
+  }
+
   // Serialize protobuf
   string serialized_manifest;
-  
+
   CheckGraph(graph);
   TEST_AND_RETURN_FALSE(manifest.AppendToString(&serialized_manifest));
   CheckGraph(graph);
 
   LOG(INFO) << "Writing final delta file header...";
   DirectFileWriter writer;
   TEST_AND_RETURN_FALSE_ERRNO(writer.Open(output_path.c_str(),
                                           O_WRONLY | O_CREAT | O_TRUNC,
                                           0644) == 0);
   ScopedFileWriterCloser writer_closer(&writer);
-  
+
   // Write header
   TEST_AND_RETURN_FALSE(writer.Write(kDeltaMagic, strlen(kDeltaMagic)) ==
                         static_cast<ssize_t>(strlen(kDeltaMagic)));
-  
+
   // Write version number
   TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer, kVersionNumber));
-  
+
   // Write protobuf length
   TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer,
                                                serialized_manifest.size()));
-  
+
   // Write protobuf
   LOG(INFO) << "Writing final delta file protobuf... "
             << serialized_manifest.size();
   TEST_AND_RETURN_FALSE(writer.Write(serialized_manifest.data(),
                                      serialized_manifest.size()) ==
                         static_cast<ssize_t>(serialized_manifest.size()));
-  
+
   // Append the data blobs
   LOG(INFO) << "Writing final delta file data blobs...";
   int blobs_fd = open(ordered_blobs_path.c_str(), O_RDONLY, 0);
   ScopedFdCloser blobs_fd_closer(&blobs_fd);
   TEST_AND_RETURN_FALSE(blobs_fd >= 0);
   for (;;) {
     char buf[kBlockSize];
     ssize_t rc = read(blobs_fd, buf, sizeof(buf));
     if (0 == rc) {
       // EOF
       break;
     }
     TEST_AND_RETURN_FALSE_ERRNO(rc > 0);
     TEST_AND_RETURN_FALSE(writer.Write(buf, rc) == rc);
   }
-  
+
+  // Write signature blob.
+  if (!private_key_path.empty()) {
+    LOG(INFO) << "Signing the update...";
+    vector<char> signature_blob;
+    TEST_AND_RETURN_FALSE(PayloadSigner::SignPayload(output_path,
+                                                     private_key_path,
+                                                     &signature_blob));
+    TEST_AND_RETURN_FALSE(writer.Write(&signature_blob[0],
+                                       signature_blob.size()) ==
+                          static_cast<ssize_t>(signature_blob.size()));
+  }
+
   LOG(INFO) << "All done. Successfully created delta file.";
   return true;
 }
 
 const char* const kBsdiffPath = "/usr/bin/bsdiff";
 const char* const kBspatchPath = "/usr/bin/bspatch";
 const char* const kDeltaMagic = "CrAU";
 
 };  // namespace chromeos_update_engine