Add microdesc format fuzzer.

src/test/fuzz/dict/microdesc

@@ -0,0 +1,7 @@
+"onion-key"
+"ntor-onion-key"
+"id"
+"a"
+"family"
+"p"
+"p6"

src/test/fuzz/fuzz_microdesc.c

@@ -0,0 +1,45 @@
+#define ROUTERPARSE_PRIVATE
+#include "or.h"
+#include "routerparse.h"
+#include "microdesc.h"
+#include "fuzzing.h"
+
+static void
+mock_dump_desc__nodump(const char *desc, const char *type)
+{
+  (void)desc;
+  (void)type;
+}
+
+int
+fuzz_init(void)
+{
+  disable_signature_checking();
+  MOCK(dump_desc, mock_dump_desc__nodump);
+  ed25519_init();
+  return 0;
+}
+
+int
+fuzz_cleanup(void)
+{
+  return 0;
+}
+
+int
+fuzz_main(const uint8_t *data, size_t sz)
+{
+  const char *str = (const char*) data;
+  smartlist_t *result = microdescs_parse_from_string((const char *)str,
+                                                     str+sz,
+                                                     0, SAVED_NOWHERE, NULL);
+  if (result) {
+    log_debug(LD_GENERAL, "Parsing okay: %d", smartlist_len(result));
+    SMARTLIST_FOREACH(result, microdesc_t *, md, microdesc_free(md));
+    smartlist_free(result);
+  } else {
+    log_debug(LD_GENERAL, "Parsing failed");
+  }
+  return 0;
+}
+

src/test/fuzz/include.am

@@ -47,12 +47,22 @@ src_test_fuzz_fuzz_extrainfo_CFLAGS = $(FUZZING_CFLAGS)
 src_test_fuzz_fuzz_extrainfo_LDFLAGS = $(FUZZING_LDFLAG)
 src_test_fuzz_fuzz_extrainfo_LDADD = $(FUZZING_LIBS)
 
+src_test_fuzz_fuzz_microdesc_SOURCES = \
+	src/test/fuzz/fuzzing_common.c \
+	src/test/fuzz/fuzz_microdesc.c
+src_test_fuzz_fuzz_microdesc_CPPFLAGS = $(FUZZING_CPPFLAGS)
+src_test_fuzz_fuzz_microdesc_CFLAGS = $(FUZZING_CFLAGS)
+src_test_fuzz_fuzz_microdesc_LDFLAGS = $(FUZZING_LDFLAG)
+src_test_fuzz_fuzz_microdesc_LDADD = $(FUZZING_LIBS)
+
 FUZZERS = \
 	src/test/fuzz/fuzz-descriptor \
 	src/test/fuzz/fuzz-extrainfo \
-	src/test/fuzz/fuzz-http
+	src/test/fuzz/fuzz-http \
+	src/test/fuzz/fuzz-microdesc
 
 noinst_PROGRAMS += $(FUZZERS)
 fuzzers: $(FUZZERS)
 
 
+