AU: Verify delta payload signature and signed hash.

omaha_hash_calculator.cc

 // Copyright (c) 2009 The Chromium OS 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/omaha_hash_calculator.h"
 
 #include <openssl/bio.h>
 #include <openssl/buffer.h>
 #include <openssl/evp.h>
 #include "base/logging.h"
@@ skipping 18 matching lines @@
                  length_param_may_be_truncated_in_SHA256_Update);
   TEST_AND_RETURN_FALSE(SHA256_Update(&ctx_, data, length) == 1);
   return true;
 }
 
 // Call Finalize() when all data has been passed in. This mostly just
 // calls OpenSSL's SHA256_Final() and then base64 encodes the hash.
 bool OmahaHashCalculator::Finalize() {
   bool success = true;
   TEST_AND_RETURN_FALSE(hash_.empty());
-  unsigned char md[SHA256_DIGEST_LENGTH];
-  TEST_AND_RETURN_FALSE(SHA256_Final(md, &ctx_) == 1);
+  TEST_AND_RETURN_FALSE(raw_hash_.empty());
+  raw_hash_.resize(SHA256_DIGEST_LENGTH);
+  TEST_AND_RETURN_FALSE(
+      SHA256_Final(reinterpret_cast<unsigned char*>(&raw_hash_[0]),
+                   &ctx_) == 1);
 
-  // Convert md to base64 encoding and store it in hash_
+  // Convert raw_hash_ to base64 encoding and store it in hash_.
   BIO *b64 = BIO_new(BIO_f_base64());
   if (!b64)
     LOG(INFO) << "BIO_new(BIO_f_base64()) failed";
   BIO *bmem = BIO_new(BIO_s_mem());
   if (!bmem)
     LOG(INFO) << "BIO_new(BIO_s_mem()) failed";
   if (b64 && bmem) {
     b64 = BIO_push(b64, bmem);
-    success = (BIO_write(b64, md, sizeof(md)) == sizeof(md));
+    success =
+        (BIO_write(b64, &raw_hash_[0], raw_hash_.size()) ==
+         static_cast<int>(raw_hash_.size()));
     if (success)
       success = (BIO_flush(b64) == 1);
 
     BUF_MEM *bptr = NULL;
     BIO_get_mem_ptr(b64, &bptr);
     hash_.assign(bptr->data, bptr->length - 1);
   }
   if (b64) {
     BIO_free_all(b64);
     b64 = NULL;
@@ skipping 24 matching lines @@
 
 string OmahaHashCalculator::OmahaHashOfString(const string& str) {
   return OmahaHashOfBytes(str.data(), str.size());
 }
 
 string OmahaHashCalculator::OmahaHashOfData(const vector<char>& data) {
   return OmahaHashOfBytes(&data[0], data.size());
 }
 
 }  // namespace chromeos_update_engine