Key-pinning back-end for directory authorities.

This module implements a key-pinning mechanism to ensure that it's
safe to use RSA keys as identitifers even as we migrate to Ed25519
keys.  It remembers, for every Ed25519 key we've seen, what the
associated Ed25519 key is.  This way, if we see a different Ed25519
key with that RSA key, we'll know that there's a mismatch.

We persist these entries to disk using a simple format, where each
line has a base64-encoded RSA SHA1 hash, then a base64-endoded
Ed25519 key.  Empty lines, misformed lines, and lines beginning with
a # are ignored. Lines beginning with @ are reserved for future
extensions.

1 files changed, 255 insertions, 0 deletions

diff --git a/src/test/test_keypin.c b/src/test/test_keypin.c
new file mode 100644
index 0000000000..afd4ca201d
--- /dev/null
+++ b/src/test/test_keypin.c
@@ -0,0 +1,255 @@
+/* Copyright (c) 2014, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "orconfig.h"
+#define KEYPIN_PRIVATE
+#include "or.h"
+#include "keypin.h"
+#include "util.h"
+
+#include "test.h"
+
+static void
+test_keypin_parse_line(void *arg)
+{
+  (void)arg;
+  keypin_ent_t *ent = NULL;
+
+  /* Good line */
+  ent = keypin_parse_journal_line(
+                "aGVyZSBpcyBhIGdvb2Qgc2hhMSE "
+                "VGhpcyBlZDI1NTE5IHNjb2ZmcyBhdCB0aGUgc2hhMS4");
+  tt_assert(ent);
+  tt_mem_op(ent->rsa_id, ==, "here is a good sha1!", 20);
+  tt_mem_op(ent->ed25519_key, ==, "This ed25519 scoffs at the sha1.", 32);
+  tor_free(ent); ent = NULL;
+
+  /* Good line with extra stuff we will ignore. */
+  ent = keypin_parse_journal_line(
+                "aGVyZSBpcyBhIGdvb2Qgc2hhMSE "
+                "VGhpcyBlZDI1NTE5IHNjb2ZmcyBhdCB0aGUgc2hhMS4helloworld");
+  tt_assert(ent);
+  tt_mem_op(ent->rsa_id, ==, "here is a good sha1!", 20);
+  tt_mem_op(ent->ed25519_key, ==, "This ed25519 scoffs at the sha1.", 32);
+  tor_free(ent); ent = NULL;
+
+  /* Bad line: no space in the middle. */
+  ent = keypin_parse_journal_line(
+                "aGVyZSBpcyBhIGdvb2Qgc2hhMSE?"
+                "VGhpcyBlZDI1NTE5IHNjb2ZmcyBhdCB0aGUgc2hhMS4");
+  tt_assert(! ent);
+
+  /* Bad line: bad base64 in RSA ID */
+  ent = keypin_parse_journal_line(
+                "aGVyZSBpcyBhIGdv!2Qgc2hhMSE "
+                "VGhpcyBlZDI1NTE5IHNjb2ZmcyBhdCB0aGUgc2hhMS4");
+  tt_assert(! ent);
+
+  /* Bad line: bad base64 in Ed25519 */
+  ent = keypin_parse_journal_line(
+                "aGVyZSBpcyBhIGdvb2Qgc2hhMSE "
+                "VGhpcyBlZDI1NTE5IHNjb2ZmcyB!dCB0aGUgc2hhMS4");
+  tt_assert(! ent);
+
+ done:
+  tor_free(ent);
+}
+
+static smartlist_t *mock_addent_got = NULL;
+static void
+mock_addent(keypin_ent_t *ent)
+{
+  smartlist_add(mock_addent_got, ent);
+  keypin_add_entry_to_map__real(ent);
+}
+
+static void
+test_keypin_parse_file(void *arg)
+{
+  (void)arg;
+
+  mock_addent_got = smartlist_new();
+  MOCK(keypin_add_entry_to_map, mock_addent);
+
+  /* Simple, minimal, correct example. */
+  const char data1[] =
+"PT09PT09PT09PT09PT09PT09PT0 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0\n"
+"TG9yYXggaXBzdW0gZ3J1dnZ1bHU cyB0aG5lZWQgYW1ldCwgc25lcmdlbGx5IG9uY2UtbGU\n"
+"ciBsZXJraW0sIHNlZCBkbyBiYXI YmFsb290IHRlbXBvciBnbHVwcGl0dXMgdXQgbGFib3I\n"
+"ZSBldCB0cnVmZnVsYSBtYWduYSA YWxpcXVhLiBVdCBlbmltIGFkIGdyaWNrbGUtZ3Jhc3M\n"
+"dmVuaWFtLCBxdWlzIG1pZmYtbXU ZmZlcmVkIGdhLXp1bXBjbyBsYWJvcmlzIG5pc2kgdXQ\n"
+"Y3J1ZmZ1bHVzIGV4IGVhIHNjaGw b3BwaXR5IGNvbnNlcXVhdC4gRHVpcyBhdXRlIHNuYXI\n"
+"Z2dsZSBpbiBzd29tZWVzd2FucyA aW4gdm9sdXB0YXRlIGF4ZS1oYWNrZXIgZXNzZSByaXA\n"
+"cHVsdXMgY3J1bW1paSBldSBtb28 ZiBudWxsYSBzbnV2di5QTFVHSFBMT1ZFUlhZWlpZLi4\n";
+
+  tt_int_op(0, ==, keypin_load_journal_impl(data1, strlen(data1)));
+  tt_int_op(8, ==, smartlist_len(mock_addent_got));
+  keypin_ent_t *ent = smartlist_get(mock_addent_got, 2);
+  tt_mem_op(ent->rsa_id, ==, "r lerkim, sed do bar", 20);
+  tt_mem_op(ent->ed25519_key, ==, "baloot tempor gluppitus ut labor", 32);
+
+  /* More complex example: weird lines, bogus lines,
+     duplicate/conflicting lines */
+  const char data2[] =
+    "PT09PT09PT09PT09PT09PT09PT0 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0\n"
+    "# This is a comment.\n"
+    "     \n"
+    "QXQgdGhlIGVuZCBvZiB0aGUgeWU YXIgS3VycmVta2FybWVycnVrIHNhaWQgdG8gaGltLCA\n"
+    "IllvdSBoYXZlIG1hZGUgYSBnb28 ZCBiZWdpbm5pbmcuIiBCdXQgbm8gbW9yZS4gV2l6YXI\n"
+    "\n"
+    "ZHMgc3BlYWsgdHJ1dGgsIGFuZCA aXQgd2FzIHRydWUgdGhhdCBhbGwgdGhlIG1hc3Rlcgo\n"
+    "@reserved for a future extension \n"
+    "eSBvZiBOYW1lcyB0aGF0IEdlZCA aGFkIHRvaWxlZCbyB3aW4gdGhhdCB5ZWFyIHdhcyA\n"
+    "eSBvZiBOYW1lcyB0aGF0IEdlZCA aGFkIHRvaWxlZCbyB3aW4gdGhhdCB5ZWFyIHdhcy"
+              "A line too long\n"
+    "dGhlIG1lcmUgc3RhcnQgb2Ygd2g YXQgaGUgbXVzdCBnbyBvb!BsZWFybmluZy4uLi4uLi4\n"
+    "ZHMgc3BlYWsgdaJ1dGgsIGFuZCA aXQgd2FzIHRydWUgdGhhdCBhbGwgdGhlIG1hc3Rlcgo\n"
+    "ZHMgc3BlYWsgdHJ1dGgsIGFuZCA aXQgd2FzIHRydaUgdGhhdCBhbGwgdGhlIG1hc3Rlcgo\n"
+    ;
+
+  tt_int_op(0, ==, keypin_load_journal_impl(data2, strlen(data2)));
+  tt_int_op(11, ==, smartlist_len(mock_addent_got));
+  ent = smartlist_get(mock_addent_got, 9);
+  tt_mem_op(ent->rsa_id, ==, "\"You have made a goo", 20);
+  tt_mem_op(ent->ed25519_key, ==, "d beginning.\" But no more. Wizar", 32);
+
+  ent = smartlist_get(mock_addent_got, 10);
+  tt_mem_op(ent->rsa_id, ==, "ds speak truth, and ", 20);
+  tt_mem_op(ent->ed25519_key, ==, "it was true that all the master\n", 32);
+
+  /* File truncated before NL */
+  const char data3[] =
+    "Tm8gZHJhZ29uIGNhbiByZXNpc3Q IHRoZSBmYXNjaW5hdGlvbiBvZiByaWRkbGluZyB0YWw";
+  tt_int_op(0, ==, keypin_load_journal_impl(data3, strlen(data3)));
+  tt_int_op(12, ==, smartlist_len(mock_addent_got));
+  ent = smartlist_get(mock_addent_got, 11);
+  tt_mem_op(ent->rsa_id, ==, "No dragon can resist", 20);
+  tt_mem_op(ent->ed25519_key, ==, " the fascination of riddling tal", 32);
+
+ done:
+  keypin_clear();
+  smartlist_free(mock_addent_got);
+}
+
+#define ADD(a,b) keypin_check_and_add((const uint8_t*)(a),(const uint8_t*)(b))
+#define LONE_RSA(a) keypin_check_lone_rsa((const uint8_t*)(a))
+
+static void
+test_keypin_add_entry(void *arg)
+{
+  (void)arg;
+  keypin_clear();
+
+  tt_int_op(KEYPIN_ADDED, ==, ADD("ambassadors-at-large",
+                                  "bread-and-butter thing-in-itself"));
+  tt_int_op(KEYPIN_ADDED, ==, ADD("gentleman-adventurer",
+                                  "cloak-and-dagger what's-his-face"));
+
+  tt_int_op(KEYPIN_FOUND, ==, ADD("ambassadors-at-large",
+                                  "bread-and-butter thing-in-itself"));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("ambassadors-at-large",
+                                  "bread-and-butter thing-in-itself"));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("gentleman-adventurer",
+                                  "cloak-and-dagger what's-his-face"));
+
+  tt_int_op(KEYPIN_ADDED, ==, ADD("Johnnies-come-lately",
+                                  "run-of-the-mill root-mean-square"));
+
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("gentleman-adventurer",
+                                     "hypersentimental closefistedness"));
+
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("disestablismentarian",
+                                     "cloak-and-dagger what's-his-face"));
+
+  tt_int_op(KEYPIN_FOUND, ==, ADD("gentleman-adventurer",
+                                  "cloak-and-dagger what's-his-face"));
+
+  tt_int_op(KEYPIN_NOT_FOUND, ==, LONE_RSA("Llanfairpwllgwyngyll"));
+  tt_int_op(KEYPIN_MISMATCH, ==, LONE_RSA("Johnnies-come-lately"));
+
+ done:
+  keypin_clear();
+}
+
+static void
+test_keypin_journal(void *arg)
+{
+  (void)arg;
+  char *contents = NULL;
+  const char *fname = get_fname("keypin-journal");
+
+  tt_int_op(0, ==, keypin_load_journal(fname)); /* ENOENT is okay */
+  update_approx_time(1217709000);
+  tt_int_op(0, ==, keypin_open_journal(fname));
+
+  tt_int_op(KEYPIN_ADDED, ==, ADD("king-of-the-herrings",
+                                  "good-for-nothing attorney-at-law"));
+  tt_int_op(KEYPIN_ADDED, ==, ADD("yellowish-red-yellow",
+                                  "salt-and-pepper high-muck-a-muck"));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("yellowish-red-yellow",
+                                  "salt-and-pepper high-muck-a-muck"));
+  keypin_close_journal();
+  keypin_clear();
+
+  tt_int_op(0, ==, keypin_load_journal(fname));
+  update_approx_time(1231041600);
+  tt_int_op(0, ==, keypin_open_journal(fname));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("yellowish-red-yellow",
+                                  "salt-and-pepper high-muck-a-muck"));
+  tt_int_op(KEYPIN_ADDED, ==, ADD("theatre-in-the-round",
+                                  "holier-than-thou jack-in-the-box"));
+  tt_int_op(KEYPIN_ADDED, ==, ADD("no-deposit-no-return",
+                                  "across-the-board will-o-the-wisp"));
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("intellectualizations",
+                                     "salt-and-pepper high-muck-a-muck"));
+  keypin_close_journal();
+  keypin_clear();
+
+  tt_int_op(0, ==, keypin_load_journal(fname));
+  update_approx_time(1412278354);
+  tt_int_op(0, ==, keypin_open_journal(fname));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("yellowish-red-yellow",
+                                  "salt-and-pepper high-muck-a-muck"));
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("intellectualizations",
+                                     "salt-and-pepper high-muck-a-muck"));
+  tt_int_op(KEYPIN_FOUND, ==, ADD("theatre-in-the-round",
+                                  "holier-than-thou jack-in-the-box"));
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("counterrevolutionary",
+                                     "holier-than-thou jack-in-the-box"));
+  tt_int_op(KEYPIN_MISMATCH, ==, ADD("no-deposit-no-return",
+                                     "floccinaucinihilipilificationism"));
+  keypin_close_journal();
+
+  contents = read_file_to_str(fname, RFTS_BIN, NULL);
+  tt_assert(contents);
+  tt_str_op(contents,==,
+    "\n"
+    "@opened-at 2008-08-02 20:30:00\n"
+    "a2luZy1vZi10aGUtaGVycmluZ3M Z29vZC1mb3Itbm90aGluZyBhdHRvcm5leS1hdC1sYXc\n"
+    "eWVsbG93aXNoLXJlZC15ZWxsb3c c2FsdC1hbmQtcGVwcGVyIGhpZ2gtbXVjay1hLW11Y2s\n"
+    "\n"
+    "@opened-at 2009-01-04 04:00:00\n"
+    "dGhlYXRyZS1pbi10aGUtcm91bmQ aG9saWVyLXRoYW4tdGhvdSBqYWNrLWluLXRoZS1ib3g\n"
+    "bm8tZGVwb3NpdC1uby1yZXR1cm4 YWNyb3NzLXRoZS1ib2FyZCB3aWxsLW8tdGhlLXdpc3A\n"
+    "\n"
+    "@opened-at 2014-10-02 19:32:34\n");
+
+ done:
+  tor_free(contents);
+  keypin_clear();
+}
+
+#undef ADD
+#undef LONE_RSA
+
+#define TEST(name, flags)                                       \
+  { #name , test_keypin_ ## name, (flags), NULL, NULL }
+
+struct testcase_t keypin_tests[] = {
+  TEST( parse_line, 0 ),
+  TEST( parse_file, TT_FORK ),
+  TEST( add_entry, TT_FORK ),
+  TEST( journal, TT_FORK ),
+  END_OF_TESTCASES
+};
+