Split microdescriptor parser into its own file.

1 files changed, 267 insertions, 0 deletions

diff --git a/src/feature/dirparse/microdesc_parse.c b/src/feature/dirparse/microdesc_parse.c
new file mode 100644
index 0000000000..005d2c53d0
--- /dev/null
+++ b/src/feature/dirparse/microdesc_parse.c
@@ -0,0 +1,267 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file microdesc_parse.c
+ * \brief Code to parse and validate microdescriptors.
+ **/
+
+#include "core/or/or.h"
+
+#include "app/config/config.h"
+#include "core/or/policies.h"
+#include "feature/dirparse/microdesc_parse.h"
+#include "feature/dirparse/parsecommon.h"
+#include "feature/dirparse/routerparse.h"
+#include "feature/nodelist/microdesc.h"
+#include "feature/nodelist/nickname.h"
+#include "feature/relay/router.h"
+#include "lib/crypt_ops/crypto_curve25519.h"
+#include "lib/crypt_ops/crypto_ed25519.h"
+#include "lib/crypt_ops/crypto_format.h"
+#include "lib/memarea/memarea.h"
+
+#include "feature/nodelist/microdesc_st.h"
+
+/** List of tokens recognized in microdescriptors */
+static token_rule_t microdesc_token_table[] = {
+  T1_START("onion-key",        K_ONION_KEY,        NO_ARGS,     NEED_KEY_1024),
+  T01("ntor-onion-key",        K_ONION_KEY_NTOR,   GE(1),       NO_OBJ ),
+  T0N("id",                    K_ID,               GE(2),       NO_OBJ ),
+  T0N("a",                     K_A,                GE(1),       NO_OBJ ),
+  T01("family",                K_FAMILY,           ARGS,        NO_OBJ ),
+  T01("p",                     K_P,                CONCAT_ARGS, NO_OBJ ),
+  T01("p6",                    K_P6,               CONCAT_ARGS, NO_OBJ ),
+  A01("@last-listed",          A_LAST_LISTED,      CONCAT_ARGS, NO_OBJ ),
+  END_OF_TABLE
+};
+
+/** Assuming that s starts with a microdesc, return the start of the
+ * *NEXT* one.  Return NULL on "not found." */
+static const char *
+find_start_of_next_microdesc(const char *s, const char *eos)
+{
+  int started_with_annotations;
+  s = eat_whitespace_eos(s, eos);
+  if (!s)
+    return NULL;
+
+#define CHECK_LENGTH() STMT_BEGIN \
+    if (s+32 > eos)               \
+      return NULL;                \
+  STMT_END
+
+#define NEXT_LINE() STMT_BEGIN            \
+    s = memchr(s, '\n', eos-s);           \
+    if (!s || s+1 >= eos)                 \
+      return NULL;                        \
+    s++;                                  \
+  STMT_END
+
+  CHECK_LENGTH();
+
+  started_with_annotations = (*s == '@');
+
+  if (started_with_annotations) {
+    /* Start by advancing to the first non-annotation line. */
+    while (*s == '@')
+      NEXT_LINE();
+  }
+  CHECK_LENGTH();
+
+  /* Now we should be pointed at an onion-key line.  If we are, then skip
+   * it. */
+  if (!strcmpstart(s, "onion-key"))
+    NEXT_LINE();
+
+  /* Okay, now we're pointed at the first line of the microdescriptor which is
+     not an annotation or onion-key.  The next line that _is_ an annotation or
+     onion-key is the start of the next microdescriptor. */
+  while (s+32 < eos) {
+    if (*s == '@' || !strcmpstart(s, "onion-key"))
+      return s;
+    NEXT_LINE();
+  }
+  return NULL;
+
+#undef CHECK_LENGTH
+#undef NEXT_LINE
+}
+
+/** Parse as many microdescriptors as are found from the string starting at
+ * <b>s</b> and ending at <b>eos</b>.  If allow_annotations is set, read any
+ * annotations we recognize and ignore ones we don't.
+ *
+ * If <b>saved_location</b> isn't SAVED_IN_CACHE, make a local copy of each
+ * descriptor in the body field of each microdesc_t.
+ *
+ * Return all newly parsed microdescriptors in a newly allocated
+ * smartlist_t. If <b>invalid_disgests_out</b> is provided, add a SHA256
+ * microdesc digest to it for every microdesc that we found to be badly
+ * formed. (This may cause duplicates) */
+smartlist_t *
+microdescs_parse_from_string(const char *s, const char *eos,
+                             int allow_annotations,
+                             saved_location_t where,
+                             smartlist_t *invalid_digests_out)
+{
+  smartlist_t *tokens;
+  smartlist_t *result;
+  microdesc_t *md = NULL;
+  memarea_t *area;
+  const char *start = s;
+  const char *start_of_next_microdesc;
+  int flags = allow_annotations ? TS_ANNOTATIONS_OK : 0;
+  const int copy_body = (where != SAVED_IN_CACHE);
+
+  directory_token_t *tok;
+
+  if (!eos)
+    eos = s + strlen(s);
+
+  s = eat_whitespace_eos(s, eos);
+  area = memarea_new();
+  result = smartlist_new();
+  tokens = smartlist_new();
+
+  while (s < eos) {
+    int okay = 0;
+
+    start_of_next_microdesc = find_start_of_next_microdesc(s, eos);
+    if (!start_of_next_microdesc)
+      start_of_next_microdesc = eos;
+
+    md = tor_malloc_zero(sizeof(microdesc_t));
+    {
+      const char *cp = tor_memstr(s, start_of_next_microdesc-s,
+                                  "onion-key");
+      const int no_onion_key = (cp == NULL);
+      if (no_onion_key) {
+        cp = s; /* So that we have *some* junk to put in the body */
+      }
+
+      md->bodylen = start_of_next_microdesc - cp;
+      md->saved_location = where;
+      if (copy_body)
+        md->body = tor_memdup_nulterm(cp, md->bodylen);
+      else
+        md->body = (char*)cp;
+      md->off = cp - start;
+      crypto_digest256(md->digest, md->body, md->bodylen, DIGEST_SHA256);
+      if (no_onion_key) {
+        log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Malformed or truncated descriptor");
+        goto next;
+      }
+    }
+
+    if (tokenize_string(area, s, start_of_next_microdesc, tokens,
+                        microdesc_token_table, flags)) {
+      log_warn(LD_DIR, "Unparseable microdescriptor");
+      goto next;
+    }
+
+    if ((tok = find_opt_by_keyword(tokens, A_LAST_LISTED))) {
+      if (parse_iso_time(tok->args[0], &md->last_listed)) {
+        log_warn(LD_DIR, "Bad last-listed time in microdescriptor");
+        goto next;
+      }
+    }
+
+    tok = find_by_keyword(tokens, K_ONION_KEY);
+    if (!crypto_pk_public_exponent_ok(tok->key)) {
+      log_warn(LD_DIR,
+               "Relay's onion key had invalid exponent.");
+      goto next;
+    }
+    router_set_rsa_onion_pkey(tok->key, &md->onion_pkey,
+                              &md->onion_pkey_len);
+    crypto_pk_free(tok->key);
+
+    if ((tok = find_opt_by_keyword(tokens, K_ONION_KEY_NTOR))) {
+      curve25519_public_key_t k;
+      tor_assert(tok->n_args >= 1);
+      if (curve25519_public_from_base64(&k, tok->args[0]) < 0) {
+        log_warn(LD_DIR, "Bogus ntor-onion-key in microdesc");
+        goto next;
+      }
+      md->onion_curve25519_pkey =
+        tor_memdup(&k, sizeof(curve25519_public_key_t));
+    }
+
+    smartlist_t *id_lines = find_all_by_keyword(tokens, K_ID);
+    if (id_lines) {
+      SMARTLIST_FOREACH_BEGIN(id_lines, directory_token_t *, t) {
+        tor_assert(t->n_args >= 2);
+        if (!strcmp(t->args[0], "ed25519")) {
+          if (md->ed25519_identity_pkey) {
+            log_warn(LD_DIR, "Extra ed25519 key in microdesc");
+            smartlist_free(id_lines);
+            goto next;
+          }
+          ed25519_public_key_t k;
+          if (ed25519_public_from_base64(&k, t->args[1])<0) {
+            log_warn(LD_DIR, "Bogus ed25519 key in microdesc");
+            smartlist_free(id_lines);
+            goto next;
+          }
+          md->ed25519_identity_pkey = tor_memdup(&k, sizeof(k));
+        }
+      } SMARTLIST_FOREACH_END(t);
+      smartlist_free(id_lines);
+    }
+
+    {
+      smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
+      if (a_lines) {
+        find_single_ipv6_orport(a_lines, &md->ipv6_addr, &md->ipv6_orport);
+        smartlist_free(a_lines);
+      }
+    }
+
+    if ((tok = find_opt_by_keyword(tokens, K_FAMILY))) {
+      int i;
+      md->family = smartlist_new();
+      for (i=0;i<tok->n_args;++i) {
+        if (!is_legal_nickname_or_hexdigest(tok->args[i])) {
+          log_warn(LD_DIR, "Illegal nickname %s in family line",
+                   escaped(tok->args[i]));
+          goto next;
+        }
+        smartlist_add_strdup(md->family, tok->args[i]);
+      }
+    }
+
+    if ((tok = find_opt_by_keyword(tokens, K_P))) {
+      md->exit_policy = parse_short_policy(tok->args[0]);
+    }
+    if ((tok = find_opt_by_keyword(tokens, K_P6))) {
+      md->ipv6_exit_policy = parse_short_policy(tok->args[0]);
+    }
+
+    smartlist_add(result, md);
+    okay = 1;
+
+    md = NULL;
+  next:
+    if (! okay && invalid_digests_out) {
+      smartlist_add(invalid_digests_out,
+                    tor_memdup(md->digest, DIGEST256_LEN));
+    }
+    microdesc_free(md);
+    md = NULL;
+
+    SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
+    memarea_clear(area);
+    smartlist_clear(tokens);
+    s = start_of_next_microdesc;
+  }
+
+  SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_clear(t));
+  memarea_drop_all(area);
+  smartlist_free(tokens);
+
+  return result;
+}