https://banu.com/bugzilla/show_bug.cgi?id=110#c4 From 526215dbb4abb1cff9a170343fa50dbda9492eb1 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Fri, 15 Mar 2013 12:34:01 +0100 Subject: [PATCH 1/2] [BB#110] secure the hashmaps by adding a seed Based on patch provided by gpernot@praksys.org on bugzilla. Signed-off-by: Michael Adam --- configure.ac | 2 ++ src/child.c | 1 + src/hashmap.c | 14 ++++++++------ 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/configure.ac b/configure.ac index ecbcba0..cc40e85 100644 --- a/configure.ac +++ b/configure.ac @@ -205,6 +205,8 @@ AC_CHECK_FUNCS([gethostname inet_ntoa memchr memset select socket strcasecmp \ AC_CHECK_FUNCS([isascii memcpy setrlimit ftruncate regcomp regexec]) AC_CHECK_FUNCS([strlcpy strlcat]) +AC_CHECK_FUNCS([time rand srand]) + dnl Enable extra warnings DESIRED_FLAGS="-fdiagnostics-show-option -Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes -Wstrict-prototypes -Wmissing-declarations -Wfloat-equal -Wundef -Wformat=2 -Wlogical-op -Wmissing-include-dirs -Wformat-nonliteral -Wold-style-definition -Wpointer-arith -Waggregate-return -Winit-self -Wpacked --std=c89 -ansi -pedantic -Wno-overlength-strings -Wc++-compat -Wno-long-long -Wno-overlength-strings -Wdeclaration-after-statement -Wredundant-decls -Wmissing-noreturn -Wshadow -Wendif-labels -Wcast-qual -Wcast-align -Wwrite-strings -Wp,-D_FORTIFY_SOURCE=2 -fno-common" diff --git a/src/child.c b/src/child.c index 34e20e0..0d778d9 100644 --- a/src/child.c +++ b/src/child.c @@ -196,6 +196,7 @@ static void child_main (struct child_s *ptr) } ptr->connects = 0; + srand(time(NULL)); while (!config.quit) { ptr->status = T_WAITING; diff --git a/src/hashmap.c b/src/hashmap.c index f46fdcb..8cf7c6b 100644 --- a/src/hashmap.c +++ b/src/hashmap.c @@ -50,6 +50,7 @@ struct hashbucket_s { }; struct hashmap_s { + uint32_t seed; unsigned int size; hashmap_iter end_iterator; @@ -65,7 +66,7 @@ struct hashmap_s { * * If any of the arguments are invalid a negative number is returned. */ -static int hashfunc (const char *key, unsigned int size) +static int hashfunc (const char *key, unsigned int size, uint32_t seed) { uint32_t hash; @@ -74,7 +75,7 @@ static int hashfunc (const char *key, unsigned int size) if (size == 0) return -ERANGE; - for (hash = tolower (*key++); *key != '\0'; key++) { + for (hash = seed; *key != '\0'; key++) { uint32_t bit = (hash & 1) ? (1 << (sizeof (uint32_t) - 1)) : 0; hash >>= 1; @@ -104,6 +105,7 @@ hashmap_t hashmap_create (unsigned int nbuckets) if (!ptr) return NULL; + ptr->seed = (uint32_t)rand(); ptr->size = nbuckets; ptr->buckets = (struct hashbucket_s *) safecalloc (nbuckets, sizeof (struct @@ -201,7 +203,7 @@ hashmap_insert (hashmap_t map, const char *key, const void *data, size_t len) if (!data || len < 1) return -ERANGE; - hash = hashfunc (key, map->size); + hash = hashfunc (key, map->size, map->seed); if (hash < 0) return hash; @@ -382,7 +384,7 @@ ssize_t hashmap_search (hashmap_t map, const char *key) if (map == NULL || key == NULL) return -EINVAL; - hash = hashfunc (key, map->size); + hash = hashfunc (key, map->size, map->seed); if (hash < 0) return hash; @@ -416,7 +418,7 @@ ssize_t hashmap_entry_by_key (hashmap_t map, const char *key, void **data) if (!map || !key || !data) return -EINVAL; - hash = hashfunc (key, map->size); + hash = hashfunc (key, map->size, map->seed); if (hash < 0) return hash; @@ -451,7 +453,7 @@ ssize_t hashmap_remove (hashmap_t map, const char *key) if (map == NULL || key == NULL) return -EINVAL; - hash = hashfunc (key, map->size); + hash = hashfunc (key, map->size, map->seed); if (hash < 0) return hash; -- 1.7.9.5 https://banu.com/bugzilla/show_bug.cgi?id=110#c5 From f1189daec6866efeb44f24073cd19d7ece86e537 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Fri, 15 Mar 2013 13:10:01 +0100 Subject: [PATCH 2/2] [BB#110] limit the number of headers per request to prevent DoS Based on patch provided by gpernot@praksys.org on bugzilla. Signed-off-by: Michael Adam --- src/reqs.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/src/reqs.c b/src/reqs.c index 2de43a8..af014ba 100644 --- a/src/reqs.c +++ b/src/reqs.c @@ -611,12 +611,19 @@ add_header_to_connection (hashmap_t hashofheaders, char *header, size_t len) } /* + * define max number of headers. + * big enough to handle legitimate cases, but limited to avoid DoS + */ +#define MAX_HEADERS 10000 + +/* * Read all the headers from the stream */ static int get_all_headers (int fd, hashmap_t hashofheaders) { char *line = NULL; char *header = NULL; + int count; char *tmp; ssize_t linelen; ssize_t len = 0; @@ -625,7 +632,7 @@ static int get_all_headers (int fd, hashmap_t hashofheaders) assert (fd >= 0); assert (hashofheaders != NULL); - for (;;) { + for (count = 0; count < MAX_HEADERS; count++) { if ((linelen = readline (fd, &line)) <= 0) { safefree (header); safefree (line); @@ -691,6 +698,14 @@ static int get_all_headers (int fd, hashmap_t hashofheaders) safefree (line); } + + /* + * if we get there, this is we reached MAX_HEADERS count + * bail out with error + */ + safefree (header); + safefree (line); + return -1; } /* -- 1.7.9.5