This time, we introduce a build-time flag (ALLOW_INSECURE_HOOKS) to make sure that anybody who wants to use these hooks is adequately warned. --- Documentation/git-upload-pack.txt | 2 + Documentation/githooks.txt | 34 +++++++++++++++ Makefile | 8 ++++ config.mak.in | 1 + t/Makefile | 4 ++ t/t5501-post-upload-pack.sh | 69 ++++++++++++++++++++++++++++++ upload-pack.c | 85 ++++++++++++++++++++++++++++++++++++- 7 files changed, 202 insertions(+), 1 deletions(-) create mode 100644 t/t5501-post-upload-pack.sh diff --git a/Documentation/git-upload-pack.txt b/Documentation/git-upload-pack.txt index b8e49dc..63f3b5c 100644 --- a/Documentation/git-upload-pack.txt +++ b/Documentation/git-upload-pack.txt @@ -20,6 +20,8 @@ The UI for the protocol is on the 'git-fetch-pack' side, and the program pair is meant to be used to pull updates from a remote repository. For push operations, see 'git-send-pack'. +After finishing the operation successfully, `post-upload-pack` +hook is called (see linkgit:githooks[5]). OPTIONS ------- diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt index 29eeae7..47bcfd1 100644 --- a/Documentation/githooks.txt +++ b/Documentation/githooks.txt @@ -310,6 +310,40 @@ Both standard output and standard error output are forwarded to 'git-send-pack' on the other end, so you can simply `echo` messages for the user. +post-upload-pack +---------------- + +Note that this hook is POTENTIALLY INSECURE. It is run as the user who +is pulling, so an attacker can make a victim run arbitrary code by +convincing him to clone a repository. To enable this hook, git must be +compiled with the ALLOW_INSECURE_HOOKS option. + +After upload-pack successfully finishes its operation, this hook is called +for logging purposes. + +The hook is passed various pieces of information, one per line, from its +standard input. Currently the following items can be fed to the hook, but +more types of information may be added in the future: + +want SHA-1:: + 40-byte hexadecimal object name the client asked to include in the + resulting pack. Can occur one or more times in the input. + +have SHA-1:: + 40-byte hexadecimal object name the client asked to exclude from + the resulting pack, claiming to have them already. Can occur zero + or more times in the input. + +time float:: + Number of seconds spent for creating the packfile. + +size decimal:: + Size of the resulting packfile in bytes. + +kind string: + Either "clone" (when the client did not give us any "have", and asked + for all our refs with "want"), or "fetch" (otherwise). + pre-auto-gc ~~~~~~~~~~~ diff --git a/Makefile b/Makefile index 57045de..e29eb33 100644 --- a/Makefile +++ b/Makefile @@ -210,6 +210,10 @@ all:: # Define JSMIN to point to JavaScript minifier that functions as # a filter to have gitweb.js minified. # +# Define ALLOW_INSECURE_HOOKS to enable hooks that have security implications +# in some setups (such as pre-/post-upload hooks that run with the user id of +# the user who is pulling). +# # Define DEFAULT_PAGER to a sensible pager command (defaults to "less") if # you want to use something different. The value will be interpreted by the # shell at runtime when it is used. @@ -1366,6 +1370,10 @@ ifdef USE_NED_ALLOCATOR COMPAT_OBJS += compat/nedmalloc/nedmalloc.o endif +ifdef ALLOW_INSECURE_HOOKS + BASIC_CFLAGS += -DALLOW_INSECURE_HOOKS +endif + ifeq ($(TCLTK_PATH),) NO_TCLTK=NoThanks endif diff --git a/config.mak.in b/config.mak.in index 67b12f7..c5bb125 100644 --- a/config.mak.in +++ b/config.mak.in @@ -58,3 +58,4 @@ SNPRINTF_RETURNS_BOGUS=@SNPRINTF_RETURNS_BOGUS@ NO_PTHREADS=@NO_PTHREADS@ THREADED_DELTA_SEARCH=@THREADED_DELTA_SEARCH@ PTHREAD_LIBS=@PTHREAD_LIBS@ +ALLOW_INSECURE_HOOKS=@ALLOW_INSECURE_HOOKS@ diff --git a/t/Makefile b/t/Makefile index bd09390..af3c99e 100644 --- a/t/Makefile +++ b/t/Makefile @@ -16,6 +16,10 @@ SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH)) T = $(wildcard t[0-9][0-9][0-9][0-9]-*.sh) TSVN = $(wildcard t91[0-9][0-9]-*.sh) +ifndef ALLOW_INSECURE_HOOKS + T := $(filter-out t5501-post-upload-pack.sh,$(T)) +endif + all: pre-clean $(MAKE) aggregate-results-and-cleanup diff --git a/t/t5501-post-upload-pack.sh b/t/t5501-post-upload-pack.sh new file mode 100644 index 0000000..d89fb51 --- /dev/null +++ b/t/t5501-post-upload-pack.sh @@ -0,0 +1,69 @@ +#!/bin/sh + +test_description='post upload-hook' + +. ./test-lib.sh + +LOGFILE=".git/post-upload-pack-log" + +test_expect_success setup ' + test_commit A && + test_commit B && + git reset --hard A && + test_commit C && + git branch prev B && + mkdir -p .git/hooks && + { + echo "#!$SHELL_PATH" && + echo "cat >post-upload-pack-log" + } >".git/hooks/post-upload-pack" && + chmod +x .git/hooks/post-upload-pack +' + +test_expect_success initial ' + rm -fr sub && + git init sub && + ( + cd sub && + git fetch --no-tags .. prev + ) && + want=$(sed -n "s/^want //p" "$LOGFILE") && + test "$want" = "$(git rev-parse --verify B)" && + ! grep "^have " "$LOGFILE" && + kind=$(sed -n "s/^kind //p" "$LOGFILE") && + test "$kind" = fetch +' + +test_expect_success second ' + rm -fr sub && + git init sub && + ( + cd sub && + git fetch --no-tags .. prev:refs/remotes/prev && + git fetch --no-tags .. master + ) && + want=$(sed -n "s/^want //p" "$LOGFILE") && + test "$want" = "$(git rev-parse --verify C)" && + have=$(sed -n "s/^have //p" "$LOGFILE") && + test "$have" = "$(git rev-parse --verify B)" && + kind=$(sed -n "s/^kind //p" "$LOGFILE") && + test "$kind" = fetch +' + +test_expect_success all ' + rm -fr sub && + HERE=$(pwd) && + git init sub && + ( + cd sub && + git clone "file://$HERE/.git" new + ) && + sed -n "s/^want //p" "$LOGFILE" | sort >actual && + git rev-parse A B C | sort >expect && + test_cmp expect actual && + ! grep "^have " "$LOGFILE" && + kind=$(sed -n "s/^kind //p" "$LOGFILE") && + test "$kind" = clone +' + +test_done diff --git a/upload-pack.c b/upload-pack.c index df15181..c992cb4 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -41,6 +41,11 @@ static int use_sideband; static int debug_fd; static int advertise_refs; static int stateless_rpc; +#ifdef ALLOW_INSECURE_HOOKS +static int allow_insecure_hooks = 1; +#else +static int allow_insecure_hooks = 0; +#endif static void reset_timeout(void) { @@ -148,8 +153,69 @@ static int do_rev_list(int fd, void *create_full_pack) return 0; } +static int feed_msg_to_hook(int fd, const char *fmt, ...) +{ + int cnt; + char buf[1024]; + va_list params; + + va_start(params, fmt); + cnt = vsprintf(buf, fmt, params); + va_end(params); + return write_in_full(fd, buf, cnt) != cnt; +} + +static int feed_obj_to_hook(const char *label, struct object_array *oa, int i, int fd) +{ + return feed_msg_to_hook(fd, "%s %s\n", label, + sha1_to_hex(oa->objects[i].item->sha1)); +} + +static int run_post_upload_pack_hook(size_t total, struct timeval *tv) +{ + const char *argv[2]; + struct child_process proc; + int err, i; + + argv[0] = "hooks/post-upload-pack"; + argv[1] = NULL; + + if (access(argv[0], X_OK) < 0) + return 0; + + if (!allow_insecure_hooks) + return 1; + + memset(&proc, 0, sizeof(proc)); + proc.argv = argv; + proc.in = -1; + proc.stdout_to_stderr = 1; + err = start_command(&proc); + if (err) + return err; + for (i = 0; !err && i < want_obj.nr; i++) + err |= feed_obj_to_hook("want", &want_obj, i, proc.in); + for (i = 0; !err && i < have_obj.nr; i++) + err |= feed_obj_to_hook("have", &have_obj, i, proc.in); + if (!err) + err |= feed_msg_to_hook(proc.in, "time %ld.%06ld\n", + (long)tv->tv_sec, (long)tv->tv_usec); + if (!err) + err |= feed_msg_to_hook(proc.in, "size %ld\n", (long)total); + if (!err) + err |= feed_msg_to_hook(proc.in, "kind %s\n", + (nr_our_refs == want_obj.nr && !have_obj.nr) + ? "clone" : "fetch"); + if (close(proc.in)) + err = 1; + if (finish_command(&proc)) + err = 1; + return err; +} + static void create_pack_file(void) { + struct timeval start_tv, tv; struct async rev_list; struct child_process pack_objects; int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr); @@ -158,9 +224,13 @@ static void create_pack_file(void) "corruption on the remote side."; int buffered = -1; ssize_t sz; + ssize_t total_sz; const char *argv[10]; int arg = 0; + gettimeofday(&start_tv, NULL); + total_sz = 0; + if (shallow_nr) { rev_list.proc = do_rev_list; rev_list.data = 0; @@ -286,7 +356,7 @@ static void create_pack_file(void) sz = xread(pack_objects.out, cp, sizeof(data) - outsz); if (0 < sz) - ; + total_sz += sz; else if (sz == 0) { close(pack_objects.out); pack_objects.out = -1; @@ -323,6 +393,19 @@ static void create_pack_file(void) } if (use_sideband) packet_flush(1); + + if (allow_insecure_hooks) { + gettimeofday(&tv, NULL); + tv.tv_sec -= start_tv.tv_sec; + if (tv.tv_usec < start_tv.tv_usec) { + tv.tv_sec--; + tv.tv_usec += 1000000; + } + tv.tv_usec -= start_tv.tv_usec; + if (run_upload_pack_hook(1, total_sz, &tv)) + warning("Running post-upload-hook failed"); + } + return; fail: -- 1.6.6.1 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html