From 1e2527a6fede996a429bd44b30a15e76ee293437 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Sun, 4 Oct 2015 01:59:06 +0200 Subject: 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". --- src/basic/hashmap.c | 2 +- src/libsystemd-network/sd-dhcp-server.c | 1 + src/libsystemd-network/sd-lldp.c | 1 + src/libsystemd/sd-bus/busctl.c | 5 +++++ src/shared/dns-domain.c | 6 ++++++ 5 files changed, 14 insertions(+), 1 deletion(-) diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c index 3c05bee56d..3e17ed30df 100644 --- a/src/basic/hashmap.c +++ b/src/basic/hashmap.c @@ -277,7 +277,7 @@ static const struct hashmap_type_info hashmap_type_info[_HASHMAP_TYPE_MAX] = { }; void string_hash_func(const void *p, struct siphash *state) { - siphash24_compress(p, strlen(p), state); + siphash24_compress(p, strlen(p) + 1, state); } int string_compare_func(const void *a, const void *b) { 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); } diff --git a/src/libsystemd/sd-bus/busctl.c b/src/libsystemd/sd-bus/busctl.c index 496b9a7b4e..49c97af339 100644 --- a/src/libsystemd/sd-bus/busctl.c +++ b/src/libsystemd/sd-bus/busctl.c @@ -630,12 +630,17 @@ typedef struct Member { static void member_hash_func(const void *p, struct siphash *state) { const Member *m = p; + uint64_t arity = 1; assert(m); assert(m->type); string_hash_func(m->type, state); + arity += !!m->name + !!m->interface; + + uint64_hash_func(&arity, state); + if (m->name) string_hash_func(m->name, state); diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c index 1517443736..5680f01bd9 100644 --- a/src/shared/dns-domain.c +++ b/src/shared/dns-domain.c @@ -399,11 +399,17 @@ void dns_name_hash_func(const void *s, struct siphash *state) { if (k > 0) r = k; + if (r == 0) + break; + label[r] = 0; ascii_strlower(label); string_hash_func(label, state); } + + /* enforce that all names are terminated by the empty label */ + string_hash_func("", state); } int dns_name_compare_func(const void *a, const void *b) { -- cgit v1.2.3-54-g00ecf