Merge branch 'bug4371_squashed'

4 files changed, 43 insertions, 30 deletions

diff --git a/changes/bug4371 b/changes/bug4371
new file mode 100644
index 0000000000..37e6faa840
--- /dev/null
+++ b/changes/bug4371
@@ -0,0 +1,3 @@
+  o Minor bugfixes:
+    - Tolerate servers with more clock skew than previously. Fixes bug 4371;
+      bugfix on 0.2.3.6-alpha.
diff --git a/src/common/tortls.c b/src/common/tortls.c
index 8cf396cdac..a41a10d136 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -212,7 +212,8 @@ static int tor_tls_context_init_one(tor_tls_context_t **ppcontext,
 static tor_tls_context_t *tor_tls_context_new(crypto_pk_env_t *identity,
                                               unsigned int key_lifetime,
                                               int is_client);
-static int check_cert_lifetime_internal(const X509 *cert, int tolerance);
+static int check_cert_lifetime_internal(int severity, const X509 *cert,
+                                   int past_tolerance, int future_tolerance);
 
 /** Global TLS contexts. We keep them here because nobody else needs
  * to touch them. */
@@ -944,7 +945,8 @@ tor_tls_cert_matches_key(const tor_tls_t *tls, const tor_cert_t *cert)
  * the key is long enough. Return 1 if the cert is good, and 0 if it's bad or
  * we couldn't check it. */
 int
-tor_tls_cert_is_valid(const tor_cert_t *cert,
+tor_tls_cert_is_valid(int severity,
+                      const tor_cert_t *cert,
                       const tor_cert_t *signing_cert,
                       int check_rsa_1024)
 {
@@ -960,8 +962,8 @@ tor_tls_cert_is_valid(const tor_cert_t *cert,
 
   /* okay, the signature checked out right.  Now let's check the check the
    * lifetime. */
-  /*XXXX tolerance might be iffy here */
-  if (check_cert_lifetime_internal(cert->cert, 60*60) < 0)
+  if (check_cert_lifetime_internal(severity, cert->cert,
+                                   48*60*60, 30*24*60*60) < 0)
     return 0;
 
   cert_key = X509_get_pubkey(cert->cert);
@@ -1924,7 +1926,7 @@ tor_tls_get_peer_cert(tor_tls_t *tls)
 
 /** Warn that a certificate lifetime extends through a certain range. */
 static void
-log_cert_lifetime(const X509 *cert, const char *problem)
+log_cert_lifetime(int severity, const X509 *cert, const char *problem)
 {
   BIO *bio = NULL;
   BUF_MEM *buf;
@@ -1934,9 +1936,10 @@ log_cert_lifetime(const X509 *cert, const char *problem)
   struct tm tm;
 
   if (problem)
-    log_warn(LD_GENERAL,
-             "Certificate %s: is your system clock set incorrectly?",
-             problem);
+    log(severity, LD_GENERAL,
+        "Certificate %s. Either their clock is set wrong, or your clock "
+        "is wrong.",
+           problem);
 
   if (!(bio = BIO_new(BIO_s_mem()))) {
     log_warn(LD_GENERAL, "Couldn't allocate BIO!"); goto end;
@@ -1958,9 +1961,9 @@ log_cert_lifetime(const X509 *cert, const char *problem)
 
   strftime(mytime, 32, "%b %d %H:%M:%S %Y GMT", tor_gmtime_r(&now, &tm));
 
-  log_warn(LD_GENERAL,
-           "(certificate lifetime runs from %s through %s. Your time is %s.)",
-           s1,s2,mytime);
+  log(severity, LD_GENERAL,
+      "(certificate lifetime runs from %s through %s. Your time is %s.)",
+      s1,s2,mytime);
 
  end:
   /* Not expected to get invoked */
@@ -2062,14 +2065,15 @@ tor_tls_verify(int severity, tor_tls_t *tls, crypto_pk_env_t **identity_key)
   return r;
 }
 
-/** Check whether the certificate set on the connection <b>tls</b> is
- * expired or not-yet-valid, give or take <b>tolerance</b>
- * seconds. Return 0 for valid, -1 for failure.
+/** Check whether the certificate set on the connection <b>tls</b> is expired
+ * give or take <b>past_tolerance</b> seconds, or not-yet-valid give or take
+ * <b>future_tolerance</b> seconds. Return 0 for valid, -1 for failure.
  *
  * NOTE: you should call tor_tls_verify before tor_tls_check_lifetime.
  */
 int
-tor_tls_check_lifetime(tor_tls_t *tls, int tolerance)
+tor_tls_check_lifetime(int severity, tor_tls_t *tls,
+                       int past_tolerance, int future_tolerance)
 {
   X509 *cert;
   int r = -1;
@@ -2077,7 +2081,8 @@ tor_tls_check_lifetime(tor_tls_t *tls, int tolerance)
   if (!(cert = SSL_get_peer_certificate(tls->ssl)))
     goto done;
 
-  if (check_cert_lifetime_internal(cert, tolerance) < 0)
+  if (check_cert_lifetime_internal(severity, cert,
+                                   past_tolerance, future_tolerance) < 0)
     goto done;
 
   r = 0;
@@ -2090,24 +2095,26 @@ tor_tls_check_lifetime(tor_tls_t *tls, int tolerance)
   return r;
 }
 
-/** Helper: check whether <b>cert</b> is currently live, give or take
- * <b>tolerance</b> seconds.  If it is live, return 0.  If it is not live,
- * log a message and return -1. */
+/** Helper: check whether <b>cert</b> is expired give or take
+ * <b>past_tolerance</b> seconds, or not-yet-valid give or take
+ * <b>future_tolerance</b> seconds.  If it is live, return 0.  If it is not
+ * live, log a message and return -1. */
 static int
-check_cert_lifetime_internal(const X509 *cert, int tolerance)
+check_cert_lifetime_internal(int severity, const X509 *cert, int past_tolerance,
+                             int future_tolerance)
 {
   time_t now, t;
 
   now = time(NULL);
 
-  t = now + tolerance;
+  t = now + future_tolerance;
   if (X509_cmp_time(X509_get_notBefore(cert), &t) > 0) {
-    log_cert_lifetime(cert, "not yet valid");
+    log_cert_lifetime(severity, cert, "not yet valid");
     return -1;
   }
-  t = now - tolerance;
+  t = now - past_tolerance;
   if (X509_cmp_time(X509_get_notAfter(cert), &t) < 0) {
-    log_cert_lifetime(cert, "already expired");
+    log_cert_lifetime(severity, cert, "already expired");
     return -1;
   }
 
diff --git a/src/common/tortls.h b/src/common/tortls.h
index d0a13cd804..673f18dfe8 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -68,7 +68,9 @@ void tor_tls_free(tor_tls_t *tls);
 int tor_tls_peer_has_cert(tor_tls_t *tls);
 tor_cert_t *tor_tls_get_peer_cert(tor_tls_t *tls);
 int tor_tls_verify(int severity, tor_tls_t *tls, crypto_pk_env_t **identity);
-int tor_tls_check_lifetime(tor_tls_t *tls, int tolerance);
+int tor_tls_check_lifetime(int severity,
+                           tor_tls_t *tls, int past_tolerance,
+                           int future_tolerance);
 int tor_tls_read(tor_tls_t *tls, char *cp, size_t len);
 int tor_tls_write(tor_tls_t *tls, const char *cp, size_t n);
 int tor_tls_handshake(tor_tls_t *tls);
@@ -123,7 +125,8 @@ int tor_tls_get_my_certs(int server,
 crypto_pk_env_t *tor_tls_get_my_client_auth_key(void);
 crypto_pk_env_t *tor_tls_cert_get_key(tor_cert_t *cert);
 int tor_tls_cert_matches_key(const tor_tls_t *tls, const tor_cert_t *cert);
-int tor_tls_cert_is_valid(const tor_cert_t *cert,
+int tor_tls_cert_is_valid(int severity,
+                          const tor_cert_t *cert,
                           const tor_cert_t *signing_cert,
                           int check_rsa_1024);
 
diff --git a/src/or/command.c b/src/or/command.c
index 5d0ebaa68a..a963d4210b 100644
--- a/src/or/command.c
+++ b/src/or/command.c
@@ -991,9 +991,9 @@ command_process_cert_cell(var_cell_t *cell, or_connection_t *conn)
     if (! tor_tls_cert_matches_key(conn->tls, link_cert)) {
       ERR("The link certificate didn't match the TLS public key");
     }
-    if (! tor_tls_cert_is_valid(link_cert, id_cert, 0))
+    if (! tor_tls_cert_is_valid(LOG_PROTOCOL_WARN, link_cert, id_cert, 0))
       ERR("The link certificate was not valid");
-    if (! tor_tls_cert_is_valid(id_cert, id_cert, 1))
+    if (! tor_tls_cert_is_valid(LOG_PROTOCOL_WARN, id_cert, id_cert, 1))
       ERR("The ID certificate was not valid");
 
     conn->handshake_state->authenticated = 1;
@@ -1026,9 +1026,9 @@ command_process_cert_cell(var_cell_t *cell, or_connection_t *conn)
       ERR("The certs we wanted were missing");
 
     /* Remember these certificates so we can check an AUTHENTICATE cell */
-    if (! tor_tls_cert_is_valid(auth_cert, id_cert, 1))
+    if (! tor_tls_cert_is_valid(LOG_PROTOCOL_WARN, auth_cert, id_cert, 1))
       ERR("The authentication certificate was not valid");
-    if (! tor_tls_cert_is_valid(id_cert, id_cert, 1))
+    if (! tor_tls_cert_is_valid(LOG_PROTOCOL_WARN, id_cert, id_cert, 1))
       ERR("The ID certificate was not valid");
 
     log_info(LD_OR, "Got some good certificates from %s:%d: "