prop224: Add unittests for decode_superencrypted().

src/or/hs_descriptor.c

@@ -1439,6 +1439,7 @@ superencrypted_auth_data_is_valid(smartlist_t *tokens)
     tok = find_by_keyword(tokens, R3_DESC_AUTH_TYPE);
     tor_assert(tok->n_args >= 1);
     if (strcmp(tok->args[0], "x25519")) {
+      log_warn(LD_DIR, "Unrecognized desc auth type");
       return 0;
     }
   }
@@ -1485,6 +1486,7 @@ decode_superencrypted(const char *message, size_t message_len,
 
   /* Do some rudimentary validation of the authentication data */
   if (!superencrypted_auth_data_is_valid(tokens)) {
+    log_warn(LD_REND, "Invalid auth data");
     goto err;
   }
 

src/test/test_hs_descriptor.c

@@ -15,6 +15,9 @@
 #include "test.h"
 #include "torcert.h"
 
+#include "test_helpers.h"
+#include "log_test_helpers.h"
+
 static hs_desc_intro_point_t *
 helper_build_intro_point(const ed25519_keypair_t *blinded_kp, time_t now,
                          const char *addr, int legacy)
@@ -1001,6 +1004,103 @@ test_desc_signature(void *arg)
   tor_free(data);
 }
 
+/* bad desc auth type */
+const char bad_superencrypted_text1[] = "desc-auth-type scoobysnack\n"
+  "desc-auth-ephemeral-key A/O8DVtnUheb3r1JqoB8uJB7wxXL1XJX3eny4yB+eFA=\n"
+  "auth-client oiNrQB8WwKo S5D02W7vKgiWIMygrBl8RQ FB//SfOBmLEx1kViEWWL1g\n"
+  "encrypted\n"
+  "-----BEGIN MESSAGE-----\n"
+  "YmVpbmcgb24gbW91bnRhaW5zLCB0aGlua2luZyBhYm91dCBjb21wdXRlcnMsIGlzIG5vdC"
+  "BiYWQgYXQgYWxs\n"
+  "-----END MESSAGE-----\n";
+
+/* bad ephemeral key */
+const char bad_superencrypted_text2[] = "desc-auth-type x25519\n"
+  "desc-auth-ephemeral-key differentalphabet\n"
+  "auth-client oiNrQB8WwKo S5D02W7vKgiWIMygrBl8RQ FB//SfOBmLEx1kViEWWL1g\n"
+  "encrypted\n"
+  "-----BEGIN MESSAGE-----\n"
+  "YmVpbmcgb24gbW91bnRhaW5zLCB0aGlua2luZyBhYm91dCBjb21wdXRlcnMsIGlzIG5vdC"
+  "BiYWQgYXQgYWxs\n"
+  "-----END MESSAGE-----\n";
+
+/* bad encrypted msg */
+const char bad_superencrypted_text3[] = "desc-auth-type x25519\n"
+  "desc-auth-ephemeral-key A/O8DVtnUheb3r1JqoB8uJB7wxXL1XJX3eny4yB+eFA=\n"
+  "auth-client oiNrQB8WwKo S5D02W7vKgiWIMygrBl8RQ FB//SfOBmLEx1kViEWWL1g\n"
+  "encrypted\n"
+  "-----BEGIN MESSAGE-----\n"
+  "SO SMALL NOT GOOD\n"
+  "-----END MESSAGE-----\n";
+
+const char correct_superencrypted_text[] = "desc-auth-type x25519\n"
+  "desc-auth-ephemeral-key A/O8DVtnUheb3r1JqoB8uJB7wxXL1XJX3eny4yB+eFA=\n"
+  "auth-client oiNrQB8WwKo S5D02W7vKgiWIMygrBl8RQ FB//SfOBmLEx1kViEWWL1g\n"
+  "auth-client Od09Qu636Qo /PKLzqewAdS/+0+vZC+MvQ dpw4NFo13zDnuPz45rxrOg\n"
+  "auth-client JRr840iGYN0 8s8cxYqF7Lx23+NducC4Qg zAafl4wPLURkuEjJreZq1g\n"
+  "encrypted\n"
+  "-----BEGIN MESSAGE-----\n"
+  "YmVpbmcgb24gbW91bnRhaW5zLCB0aGlua2luZyBhYm91dCBjb21wdXRlcnMsIGlzIG5vdC"
+  "BiYWQgYXQgYWxs\n"
+  "-----END MESSAGE-----\n";
+
+const char correct_encrypted_plaintext[] = "being on mountains, "
+  "thinking about computers, is not bad at all";
+
+static void
+test_parse_hs_desc_superencrypted(void *arg)
+{
+  (void) arg;
+  int retval;
+  uint8_t *encrypted_out = NULL;
+
+  {
+    setup_full_capture_of_logs(LOG_WARN);
+    retval = decode_superencrypted(bad_superencrypted_text1,
+                                   strlen(bad_superencrypted_text1),
+                                   &encrypted_out);
+    tt_int_op(retval, ==, 0);
+    tt_assert(!encrypted_out);
+    expect_log_msg_containing("Unrecognized desc auth type");
+    teardown_capture_of_logs();
+  }
+
+  {
+    setup_full_capture_of_logs(LOG_WARN);
+    retval = decode_superencrypted(bad_superencrypted_text2,
+                                   strlen(bad_superencrypted_text2),
+                                   &encrypted_out);
+    tt_int_op(retval, ==, 0);
+    tt_assert(!encrypted_out);
+    expect_log_msg_containing("Bogus desc auth key in HS desc");
+    teardown_capture_of_logs();
+  }
+
+  {
+    setup_full_capture_of_logs(LOG_WARN);
+    retval = decode_superencrypted(bad_superencrypted_text3,
+                                   strlen(bad_superencrypted_text3),
+                                   &encrypted_out);
+    tt_int_op(retval, ==, 0);
+    tt_assert(!encrypted_out);
+    expect_log_msg_containing("Length of descriptor\'s encrypted data "
+                              "is too small.");
+    teardown_capture_of_logs();
+  }
+
+  /* Now finally the good one */
+  retval = decode_superencrypted(correct_superencrypted_text,
+                                 strlen(correct_superencrypted_text),
+                                 &encrypted_out);
+
+  tt_int_op(retval, ==, strlen(correct_encrypted_plaintext));
+  tt_mem_op(encrypted_out, OP_EQ, correct_encrypted_plaintext,
+            strlen(correct_encrypted_plaintext));
+
+ done:
+  tor_free(encrypted_out);
+}
+
 struct testcase_t hs_descriptor[] = {
   /* Encoding tests. */
   { "cert_encoding", test_cert_encoding, TT_FORK,
@@ -1030,6 +1130,9 @@ struct testcase_t hs_descriptor[] = {
   { "desc_signature", test_desc_signature, TT_FORK,
     NULL, NULL },
 
+  { "parse_hs_desc_superencrypted", test_parse_hs_desc_superencrypted,
+    TT_FORK, NULL, NULL },
+
   END_OF_TESTCASES
 };