Version the pickled objects and check for errors when unpickling them

1 files changed, 11 insertions, 0 deletions

diff --git a/src/session.cpp b/src/session.cpp
index 4abf6cf..654cf1f 100644
--- a/src/session.cpp
+++ b/src/session.cpp
@@ -353,11 +353,15 @@ std::size_t olm::Session::decrypt(
     return result;
 }
 
+namespace {
+static const std::uint32_t SESSION_PICKLE_VERSION = 1;
+}
 
 std::size_t olm::pickle_length(
     Session const & value
 ) {
     std::size_t length = 0;
+    length += olm::pickle_length(SESSION_PICKLE_VERSION);
     length += olm::pickle_length(value.received_message);
     length += olm::pickle_length(value.alice_identity_key);
     length += olm::pickle_length(value.alice_base_key);
@@ -371,6 +375,7 @@ std::uint8_t * olm::pickle(
     std::uint8_t * pos,
     Session const & value
 ) {
+    pos = olm::pickle(pos, SESSION_PICKLE_VERSION);
     pos = olm::pickle(pos, value.received_message);
     pos = olm::pickle(pos, value.alice_identity_key);
     pos = olm::pickle(pos, value.alice_base_key);
@@ -384,6 +389,12 @@ std::uint8_t const * olm::unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
     Session & value
 ) {
+    uint32_t pickle_version;
+    pos = olm::unpickle(pos, end, pickle_version);
+    if (pickle_version != SESSION_PICKLE_VERSION) {
+        value.last_error = olm::ErrorCode::UNKNOWN_PICKLE_VERSION;
+        return end;
+    }
     pos = olm::unpickle(pos, end, value.received_message);
     pos = olm::unpickle(pos, end, value.alice_identity_key);
     pos = olm::unpickle(pos, end, value.alice_base_key);