hashmap: hash_funcs - make inputs unambiguous

Make sure all variable-length inputs are properly terminated or that
their length is encoded in some way. This avoids ambiguity of
adjacent inputs.

E.g., in case of a hash function taking two strings, compressing "ab"
followed by "c" is now distinct from "a" followed by "bc".

2 files changed, 2 insertions, 0 deletions

diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c
index 4ea5a29e5c..d941e6c0de 100644
--- a/src/libsystemd-network/sd-dhcp-server.c
+++ b/src/libsystemd-network/sd-dhcp-server.c
@@ -117,6 +117,7 @@ void client_id_hash_func(const void *p, struct siphash *state) {
         assert(id->length);
         assert(id->data);
 
+        siphash24_compress(&id->length, sizeof(id->length), state);
         siphash24_compress(id->data, id->length, state);
 }
 
diff --git a/src/libsystemd-network/sd-lldp.c b/src/libsystemd-network/sd-lldp.c
index b9bf4d3c00..0b7d35cdf1 100644
--- a/src/libsystemd-network/sd-lldp.c
+++ b/src/libsystemd-network/sd-lldp.c
@@ -74,6 +74,7 @@ static void chassis_id_hash_func(const void *p, struct siphash *state) {
         assert(id);
         assert(id->data);
 
+        siphash24_compress(&id->length, sizeof(id->length), state);
         siphash24_compress(id->data, id->length, state);
 }