oss-fuzz: Add new fuzzer for libcharon IKE message parser

Closes strongswan/strongswan#2988

Signed-off-by: Arthur Chan <[email protected]>

fuzz/Makefile.am

@@ -1,5 +1,6 @@
 AM_CPPFLAGS = @CPPFLAGS@ \
 	@FUZZING_CFLAGS@ \
+	-I$(top_srcdir)/src/libcharon \
 	-I$(top_srcdir)/src/libstrongswan \
 	-I$(top_srcdir)/src/libimcv \
 	-I$(top_srcdir)/src/libtncif \
@@ -25,8 +26,12 @@ pb_tnc_ldflags = \
 	$(top_builddir)/src/libtncif/.libs/libtncif.a \
 	$(fuzz_ldflags)
 
+ike_ldflags = \
+	$(top_builddir)/src/libcharon/.libs/libcharon.a \
+	$(fuzz_ldflags)
+
 FUZZ_TARGETS=fuzz_certs fuzz_crls fuzz_ocsp_req fuzz_ocsp_rsp \
-	fuzz_ids fuzz_pa_tnc fuzz_pb_tnc
+	fuzz_ids fuzz_pa_tnc fuzz_pb_tnc fuzz_ike
 
 all-local: $(FUZZ_TARGETS)
 
@@ -53,6 +58,9 @@ fuzz_pa_tnc: fuzz_pa_tnc.c ${libfuzzer}
 fuzz_pb_tnc: fuzz_pb_tnc.c ${libfuzzer}
 	$(CC) $(AM_CPPFLAGS) $(CFLAGS) -o $@ $< $(pb_tnc_ldflags)
 
+fuzz_ike: fuzz_ike.c ${libfuzzer}
+	$(CC) $(AM_CPPFLAGS) $(CFLAGS) -o $@ $< $(ike_ldflags)
+
 noinst_LIBRARIES = libFuzzerLocal.a
 libFuzzerLocal_a_SOURCES = libFuzzerLocal.c
 libFuzzerLocal_a_LIBADD = $(top_builddir)/src/libstrongswan/libstrongswan.la
@@ -60,7 +68,8 @@ libFuzzerLocal_a_LIBADD = $(top_builddir)/src/libstrongswan/libstrongswan.la
 check: all
 	for f in $(FUZZ_TARGETS); do \
 		corpus=$${f#fuzz_}; \
-		./$$f $(FUZZING_CORPORA)/$${corpus}/* || exit 1; \
-		crashes=$(FUZZING_CORPORA)/$${corpus}-crash; \
+		initial=$(FUZZING_CORPORA)/$${corpus}; \
+		crashes=$${initial}-crash; \
+		test ! -d $${initial} || ./$$f $${initial}/* || exit 1; \
 		test ! -d $${crashes} || ./$$f $${crashes}/* || exit 1; \
 	done