diff options
Diffstat (limited to 'docs/security.rst')
| -rw-r--r-- | docs/security.rst | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/docs/security.rst b/docs/security.rst index e865f83..d854612 100644 --- a/docs/security.rst +++ b/docs/security.rst @@ -26,9 +26,9 @@ The following data is regarded as **trusted**. It must be under the control of the application writer. Malicious data in these structures could cause security issues, such as execution of arbitrary code: -1. Callback and extension fields in message structures given to pb_encode() - and pb_decode(). These fields are memory pointers, and are generated - depending on the .proto file. +1. Callback, pointer and extension fields in message structures given to + pb_encode() and pb_decode(). These fields are memory pointers, and are + generated depending on the message definition in the .proto file. 2. The automatically generated field definitions, i.e. *pb_field_t* lists. 3. Contents of the *pb_istream_t* and *pb_ostream_t* structures (this does not mean the contents of the stream itself, just the stream definition). @@ -38,8 +38,11 @@ these will cause "garbage in, garbage out" behaviour. It will not cause buffer overflows, information disclosure or other security problems: 1. All data read from *pb_istream_t*. -2. All fields in message structures, except callbacks and extensions. - (Beginning with nanopb-0.2.4, in earlier versions the field sizes are partially unchecked.) +2. All fields in message structures, except: + + - callbacks (*pb_callback_t* structures) + - pointer fields (malloc support) and *_count* fields for pointers + - extensions (*pb_extension_t* structures) Invariants ========== @@ -76,4 +79,6 @@ The following list is not comprehensive: stop a denial of service attack from using an infinite message. 4. If using network sockets as streams, a timeout should be set to stop denial of service attacks. - +5. If using *malloc()* support, some method of limiting memory use should be + employed. This can be done by defining custom *pb_realloc()* function. + Nanopb will properly detect and handle failed memory allocations. |