AU: Verify delta payload signature and signed hash.
The signature and hash are verified only if the public key file exists.
This means that currently this feature is desabled until we install a public
key.
BUG=5663
TEST=unit tests, applied a signed delta update on the server
Change-Id: I5be72f7fde88400587f8aae0c7d5745c79fc4428
Review URL: http://codereview.chromium.org/3592008
diff --git a/payload_signer.cc b/payload_signer.cc
index 5b0c267..de80a5b 100644
--- a/payload_signer.cc
+++ b/payload_signer.cc
@@ -94,4 +94,56 @@
return true;
}
+bool PayloadSigner::VerifySignature(const std::vector<char>& signature_blob,
+ const std::string& public_key_path,
+ std::vector<char>* out_hash_data) {
+ TEST_AND_RETURN_FALSE(!public_key_path.empty());
+
+ Signatures signatures;
+ TEST_AND_RETURN_FALSE(signatures.ParseFromArray(&signature_blob[0],
+ signature_blob.size()));
+
+ // Finds a signature that matches the current version.
+ int sig_index = 0;
+ for (; sig_index < signatures.signatures_size(); sig_index++) {
+ const Signatures_Signature& signature = signatures.signatures(sig_index);
+ if (signature.has_version() &&
+ signature.version() == kSignatureMessageVersion) {
+ break;
+ }
+ }
+ TEST_AND_RETURN_FALSE(sig_index < signatures.signatures_size());
+
+ const Signatures_Signature& signature = signatures.signatures(sig_index);
+ const string sig_data = signature.data();
+ string sig_path;
+ TEST_AND_RETURN_FALSE(
+ utils::MakeTempFile("/var/run/signature.XXXXXX", &sig_path, NULL));
+ ScopedPathUnlinker sig_path_unlinker(sig_path);
+ TEST_AND_RETURN_FALSE(utils::WriteFile(sig_path.c_str(),
+ &sig_data[0],
+ sig_data.size()));
+ string hash_path;
+ TEST_AND_RETURN_FALSE(
+ utils::MakeTempFile("/var/run/hash.XXXXXX", &hash_path, NULL));
+ ScopedPathUnlinker hash_path_unlinker(hash_path);
+
+ // TODO(petkov): This runs on the client so it will be cleaner if it uses
+ // direct openssl library calls.
+ vector<string> cmd;
+ SplitString("/usr/bin/openssl rsautl -verify -pubin -inkey x -in x -out x",
+ ' ',
+ &cmd);
+ cmd[cmd.size() - 5] = public_key_path;
+ cmd[cmd.size() - 3] = sig_path;
+ cmd[cmd.size() - 1] = hash_path;
+
+ int return_code = 0;
+ TEST_AND_RETURN_FALSE(Subprocess::SynchronousExec(cmd, &return_code));
+ TEST_AND_RETURN_FALSE(return_code == 0);
+
+ TEST_AND_RETURN_FALSE(utils::ReadFile(hash_path, out_hash_data));
+ return true;
+}
+
} // namespace chromeos_update_engine