[tor-commits] [tor/main] Quick-and-dirty fuzzer for inner-encrypted layer of hsv3 desc.
nickm at torproject.org
nickm at torproject.org
Sat Oct 16 14:51:49 UTC 2021
commit 88987ce8ebeea3fa2b8989cbe6dccb95d5d223e8
Author: Nick Mathewson <nickm at torproject.org>
Date: Tue Jun 8 11:01:47 2021 -0400
Quick-and-dirty fuzzer for inner-encrypted layer of hsv3 desc.
Based on hsv3 outer-layer fuzzer; some code may be unnecessary.
---
scripts/codegen/fuzzing_include_am.py | 3 +-
src/feature/hs/hs_descriptor.c | 10 +--
src/feature/hs/hs_descriptor.h | 10 +++
src/test/fuzz/fuzz_hsdescv3_inner.c | 119 ++++++++++++++++++++++++++++++++++
src/test/fuzz/include.am | 29 +++++++++
5 files changed, 164 insertions(+), 7 deletions(-)
diff --git a/scripts/codegen/fuzzing_include_am.py b/scripts/codegen/fuzzing_include_am.py
index b52b956f81..d2d73a3c06 100755
--- a/scripts/codegen/fuzzing_include_am.py
+++ b/scripts/codegen/fuzzing_include_am.py
@@ -11,11 +11,10 @@ FUZZERS = """
diff
diff-apply
extrainfo
- hsdescv2
hsdescv3
+ hsdescv3-inner
http
http-connect
- iptsv2
microdesc
socks
strops
diff --git a/src/feature/hs/hs_descriptor.c b/src/feature/hs/hs_descriptor.c
index 10eca2176b..cad442718b 100644
--- a/src/feature/hs/hs_descriptor.c
+++ b/src/feature/hs/hs_descriptor.c
@@ -1639,10 +1639,10 @@ desc_decrypt_superencrypted(const hs_descriptor_t *desc, char **decrypted_out)
* decrypted_out which contains the encrypted layer of the descriptor.
* Return the length of decrypted_out on success else 0 is returned and
* decrypted_out is set to NULL. */
-static size_t
-desc_decrypt_encrypted(const hs_descriptor_t *desc,
- const curve25519_secret_key_t *client_auth_sk,
- char **decrypted_out)
+MOCK_IMPL(STATIC size_t,
+desc_decrypt_encrypted,(const hs_descriptor_t *desc,
+ const curve25519_secret_key_t *client_auth_sk,
+ char **decrypted_out))
{
size_t encrypted_len = 0;
char *encrypted_plaintext = NULL;
@@ -2259,7 +2259,7 @@ desc_decode_superencrypted_v3(const hs_descriptor_t *desc,
/** Decode the version 3 encrypted section of the given descriptor desc. The
* desc_encrypted_out will be populated with the decoded data. */
-static hs_desc_decode_status_t
+STATIC hs_desc_decode_status_t
desc_decode_encrypted_v3(const hs_descriptor_t *desc,
const curve25519_secret_key_t *client_auth_sk,
hs_desc_encrypted_data_t *desc_encrypted_out)
diff --git a/src/feature/hs/hs_descriptor.h b/src/feature/hs/hs_descriptor.h
index 7e437faeb8..5f3531fac7 100644
--- a/src/feature/hs/hs_descriptor.h
+++ b/src/feature/hs/hs_descriptor.h
@@ -339,6 +339,16 @@ MOCK_DECL(STATIC size_t, decrypt_desc_layer,(const hs_descriptor_t *desc,
bool is_superencrypted_layer,
char **decrypted_out));
+STATIC hs_desc_decode_status_t desc_decode_encrypted_v3(
+ const hs_descriptor_t *desc,
+ const curve25519_secret_key_t *client_auth_sk,
+ hs_desc_encrypted_data_t *desc_encrypted_out);
+
+MOCK_DECL(STATIC size_t, desc_decrypt_encrypted,(
+ const hs_descriptor_t *desc,
+ const curve25519_secret_key_t *client_auth_sk,
+ char **decrypted_out));
+
#endif /* defined(HS_DESCRIPTOR_PRIVATE) */
#endif /* !defined(TOR_HS_DESCRIPTOR_H) */
diff --git a/src/test/fuzz/fuzz_hsdescv3_inner.c b/src/test/fuzz/fuzz_hsdescv3_inner.c
new file mode 100644
index 0000000000..5aa719f5c3
--- /dev/null
+++ b/src/test/fuzz/fuzz_hsdescv3_inner.c
@@ -0,0 +1,119 @@
+/* Copyright (c) 2017-2021, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#define HS_DESCRIPTOR_PRIVATE
+
+#include "core/or/or.h"
+#include "trunnel/ed25519_cert.h" /* Trunnel interface. */
+#include "lib/crypt_ops/crypto_ed25519.h"
+#include "feature/hs/hs_descriptor.h"
+#include "feature/dirparse/unparseable.h"
+
+#include "test/fuzz/fuzzing.h"
+
+static void
+mock_dump_desc__nodump(const char *desc, const char *type)
+{
+ (void)desc;
+ (void)type;
+}
+
+static int
+mock_rsa_ed25519_crosscert_check(const uint8_t *crosscert,
+ const size_t crosscert_len,
+ const crypto_pk_t *rsa_id_key,
+ const ed25519_public_key_t *master_key,
+ const time_t reject_if_expired_before)
+{
+ (void) crosscert;
+ (void) crosscert_len;
+ (void) rsa_id_key;
+ (void) master_key;
+ (void) reject_if_expired_before;
+ return 0;
+}
+
+static size_t
+mock_decrypt_desc_layer(const hs_descriptor_t *desc,
+ const uint8_t *descriptor_cookie,
+ bool is_superencrypted_layer,
+ char **decrypted_out)
+{
+ (void)is_superencrypted_layer;
+ (void)desc;
+ (void)descriptor_cookie;
+ const size_t overhead = HS_DESC_ENCRYPTED_SALT_LEN + DIGEST256_LEN;
+ const uint8_t *encrypted_blob = (is_superencrypted_layer)
+ ? desc->plaintext_data.superencrypted_blob
+ : desc->superencrypted_data.encrypted_blob;
+ size_t encrypted_blob_size = (is_superencrypted_layer)
+ ? desc->plaintext_data.superencrypted_blob_size
+ : desc->superencrypted_data.encrypted_blob_size;
+
+ if (encrypted_blob_size < overhead)
+ return 0;
+ *decrypted_out = tor_memdup_nulterm(
+ encrypted_blob + HS_DESC_ENCRYPTED_SALT_LEN,
+ encrypted_blob_size - overhead);
+ size_t result = strlen(*decrypted_out);
+ if (result) {
+ return result;
+ } else {
+ tor_free(*decrypted_out);
+ return 0;
+ }
+}
+
+static const uint8_t *decrypted_data = NULL;
+static size_t decrypted_len = 0;
+static size_t
+mock_desc_decrypt_encrypted(const hs_descriptor_t *desc,
+ const curve25519_secret_key_t *client_auth_sk,
+ char **decrypted_out)
+{
+ (void)desc;
+ (void)client_auth_sk;
+ *decrypted_out = (char*)tor_memdup_nulterm(decrypted_data, decrypted_len);
+ return decrypted_len;
+}
+
+int
+fuzz_init(void)
+{
+ disable_signature_checking();
+ MOCK(dump_desc, mock_dump_desc__nodump);
+ MOCK(rsa_ed25519_crosscert_check, mock_rsa_ed25519_crosscert_check);
+ MOCK(decrypt_desc_layer, mock_decrypt_desc_layer);
+ MOCK(desc_decrypt_encrypted, mock_desc_decrypt_encrypted);
+ ed25519_init();
+ return 0;
+}
+
+int
+fuzz_cleanup(void)
+{
+ return 0;
+}
+
+int
+fuzz_main(const uint8_t *data, size_t sz)
+{
+ decrypted_data = data;
+ decrypted_len = sz;
+
+ hs_descriptor_t *desc = tor_malloc_zero(sizeof(hs_descriptor_t));
+ hs_desc_encrypted_data_t *output = tor_malloc_zero(sizeof(*output));
+ curve25519_secret_key_t *client_auth_sk = NULL;
+ hs_desc_decode_status_t status;
+
+ status = desc_decode_encrypted_v3(desc, client_auth_sk, output);
+ if (status == HS_DESC_DECODE_OK) {
+ log_debug(LD_GENERAL, "Decoding okay");
+ } else {
+ log_debug(LD_GENERAL, "Decoding failed");
+ }
+
+ hs_descriptor_free(desc);
+ hs_desc_encrypted_data_free(output);
+ return 0;
+}
diff --git a/src/test/fuzz/include.am b/src/test/fuzz/include.am
index 9bdced9e6f..a72df754a8 100644
--- a/src/test/fuzz/include.am
+++ b/src/test/fuzz/include.am
@@ -93,6 +93,16 @@ src_test_fuzz_fuzz_hsdescv3_LDFLAGS = $(FUZZING_LDFLAG)
src_test_fuzz_fuzz_hsdescv3_LDADD = $(FUZZING_LIBS)
endif
+if UNITTESTS_ENABLED
+src_test_fuzz_fuzz_hsdescv3_inner_SOURCES = \
+ src/test/fuzz/fuzzing_common.c \
+ src/test/fuzz/fuzz_hsdescv3_inner.c
+src_test_fuzz_fuzz_hsdescv3_inner_CPPFLAGS = $(FUZZING_CPPFLAGS)
+src_test_fuzz_fuzz_hsdescv3_inner_CFLAGS = $(FUZZING_CFLAGS)
+src_test_fuzz_fuzz_hsdescv3_inner_LDFLAGS = $(FUZZING_LDFLAG)
+src_test_fuzz_fuzz_hsdescv3_inner_LDADD = $(FUZZING_LIBS)
+endif
+
if UNITTESTS_ENABLED
src_test_fuzz_fuzz_http_SOURCES = \
src/test/fuzz/fuzzing_common.c \
@@ -161,6 +171,7 @@ FUZZERS = \
src/test/fuzz/fuzz-diff-apply \
src/test/fuzz/fuzz-extrainfo \
src/test/fuzz/fuzz-hsdescv3 \
+ src/test/fuzz/fuzz-hsdescv3-inner \
src/test/fuzz/fuzz-http \
src/test/fuzz/fuzz-http-connect \
src/test/fuzz/fuzz-microdesc \
@@ -226,6 +237,15 @@ src_test_fuzz_lf_fuzz_hsdescv3_LDFLAGS = $(LIBFUZZER_LDFLAG)
src_test_fuzz_lf_fuzz_hsdescv3_LDADD = $(LIBFUZZER_LIBS)
endif
+if UNITTESTS_ENABLED
+src_test_fuzz_lf_fuzz_hsdescv3_inner_SOURCES = \
+ $(src_test_fuzz_fuzz_hsdescv3_inner_SOURCES)
+src_test_fuzz_lf_fuzz_hsdescv3_inner_CPPFLAGS = $(LIBFUZZER_CPPFLAGS)
+src_test_fuzz_lf_fuzz_hsdescv3_inner_CFLAGS = $(LIBFUZZER_CFLAGS)
+src_test_fuzz_lf_fuzz_hsdescv3_inner_LDFLAGS = $(LIBFUZZER_LDFLAG)
+src_test_fuzz_lf_fuzz_hsdescv3_inner_LDADD = $(LIBFUZZER_LIBS)
+endif
+
if UNITTESTS_ENABLED
src_test_fuzz_lf_fuzz_http_SOURCES = \
$(src_test_fuzz_fuzz_http_SOURCES)
@@ -287,6 +307,7 @@ LIBFUZZER_FUZZERS = \
src/test/fuzz/lf-fuzz-diff-apply \
src/test/fuzz/lf-fuzz-extrainfo \
src/test/fuzz/lf-fuzz-hsdescv3 \
+ src/test/fuzz/lf-fuzz-hsdescv3-inner \
src/test/fuzz/lf-fuzz-http \
src/test/fuzz/lf-fuzz-http-connect \
src/test/fuzz/lf-fuzz-microdesc \
@@ -343,6 +364,13 @@ src_test_fuzz_liboss_fuzz_hsdescv3_a_CPPFLAGS = $(LIBOSS_FUZZ_CPPFLAGS)
src_test_fuzz_liboss_fuzz_hsdescv3_a_CFLAGS = $(LIBOSS_FUZZ_CFLAGS)
endif
+if UNITTESTS_ENABLED
+src_test_fuzz_liboss_fuzz_hsdescv3_inner_a_SOURCES = \
+ $(src_test_fuzz_fuzz_hsdescv3_inner_SOURCES)
+src_test_fuzz_liboss_fuzz_hsdescv3_inner_a_CPPFLAGS = $(LIBOSS_FUZZ_CPPFLAGS)
+src_test_fuzz_liboss_fuzz_hsdescv3_inner_a_CFLAGS = $(LIBOSS_FUZZ_CFLAGS)
+endif
+
if UNITTESTS_ENABLED
src_test_fuzz_liboss_fuzz_http_a_SOURCES = \
$(src_test_fuzz_fuzz_http_SOURCES)
@@ -392,6 +420,7 @@ OSS_FUZZ_FUZZERS = \
src/test/fuzz/liboss-fuzz-diff-apply.a \
src/test/fuzz/liboss-fuzz-extrainfo.a \
src/test/fuzz/liboss-fuzz-hsdescv3.a \
+ src/test/fuzz/liboss-fuzz-hsdescv3-inner.a \
src/test/fuzz/liboss-fuzz-http.a \
src/test/fuzz/liboss-fuzz-http-connect.a \
src/test/fuzz/liboss-fuzz-microdesc.a \
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