commit f2f718bca504d0fe1cce566185f8c17e23862335 Author: George Kadianakis desnacked@riseup.net Date: Mon Mar 30 16:33:30 2020 +0300

hs-v3: Change all-zeroes hard-assert to a BUG-and-err.

And also disallow all-zeroes keys from the filesystem; add a test for it too. --- src/feature/hs/hs_client.c | 7 +++++++ src/feature/hs/hs_descriptor.c | 8 ++++++-- src/test/test_hs_client.c | 4 ++++ 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/feature/hs/hs_client.c b/src/feature/hs/hs_client.c index af8cb0b41..da1202b64 100644 --- a/src/feature/hs/hs_client.c +++ b/src/feature/hs/hs_client.c @@ -2132,6 +2132,13 @@ parse_auth_file_content(const char *client_key_str) "can't be decoded: %s", seckey_b32); goto err; } + + if (fast_mem_is_zero((const char*)auth->enc_seckey.secret_key, + sizeof(auth->enc_seckey.secret_key))) { + log_warn(LD_REND, "Client authorization private key can't be all-zeroes"); + goto err; + } + strncpy(auth->onion_address, onion_address, HS_SERVICE_ADDR_LEN_BASE32);

/* We are reading this from the disk, so set the permanent flag anyway. */ diff --git a/src/feature/hs/hs_descriptor.c b/src/feature/hs/hs_descriptor.c index 65d6c7a58..27823aa79 100644 --- a/src/feature/hs/hs_descriptor.c +++ b/src/feature/hs/hs_descriptor.c @@ -1424,10 +1424,14 @@ decrypt_descriptor_cookie(const hs_descriptor_t *desc, tor_assert(!fast_mem_is_zero( (char *) &desc->superencrypted_data.auth_ephemeral_pubkey, sizeof(desc->superencrypted_data.auth_ephemeral_pubkey))); - tor_assert(!fast_mem_is_zero((char *) client_auth_sk, - sizeof(*client_auth_sk))); tor_assert(!fast_mem_is_zero((char *) desc->subcredential, DIGEST256_LEN));

+ /* Catch potential code-flow cases of an unitialized private key sneaking + * into this function. */ + if (BUG(fast_mem_is_zero((char *)client_auth_sk, sizeof(*client_auth_sk)))) { + goto done; + } + /* Get the KEYS component to derive the CLIENT-ID and COOKIE-KEY. */ keystream_length = build_descriptor_cookie_keys(desc->subcredential, DIGEST256_LEN, diff --git a/src/test/test_hs_client.c b/src/test/test_hs_client.c index 5f7fe9c40..4d938e463 100644 --- a/src/test/test_hs_client.c +++ b/src/test/test_hs_client.c @@ -732,6 +732,10 @@ test_parse_auth_file_content(void *arg) /* Bigger key than it should be */ tt_assert(!parse_auth_file_content("xx:descriptor:x25519:" "vjqea4jbhwwc4hto7ekyvqfbeodghbaq6nxi45hz4wr3qvhqv3yqa")); + /* All-zeroes key */ + tt_assert(!parse_auth_file_content("xx:descriptor:x25519:" + "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")); + done: tor_free(auth); }