Changeset 5483:9373afa9278f

Timestamp:

2008-08-20 22:33:52 (4 months ago)

Author:

Rocco Rutte <pdmef@…>

Branch:

HEAD

Message:

Port certificate host checking from msmtp to mutt.
It supports IDN, wildcards and extracting the hostname from
subject alternative field as well as common name which should
be the same gnutls supports. Closes #3087.

Files:

• ChangeLog (modified) (1 diff)
• mutt_ssl.c (modified) (4 diffs)

ChangeLog

@@ +1 @@
+2008-08-19 13:17 -0700  Brendan Cully  <brendan@kublai.com>  (573d1aab3c89)
+
+        * init.c: Silence an incorrect uninitialized variable warning.
+
+2008-08-19 13:14 -0700  Brendan Cully  <brendan@kublai.com>  (6b4f25cd9dac)
+
+        * ChangeLog, init.h: Better documentation for how quote_regexp
+        determines quote level. Closes #1463.
+
 2008-08-19 09:39 +0200  Rocco Rutte  <pdmef@gmx.net>  (3e850c6e43fd)
 

mutt_ssl.c

@@ -23 +23 @@
 #include <openssl/ssl.h>
 #include <openssl/x509.h>
+#include <openssl/x509v3.h>
 #include <openssl/err.h>
 #include <openssl/rand.h>
@@ -35 +36 @@
 #include "mutt_curses.h"
 #include "mutt_ssl.h"
+#include "mutt_idna.h"
 
 #if OPENSSL_VERSION_NUMBER >= 0x00904000L
@@ -589 +591 @@
 }
 
-static int check_certificate_hostname(X509 *peercert, const char *host)
-{
-  char cert_CN[STRING];
-
-  if (!host || !*host)
-    return 0;
-
-  X509_NAME_get_text_by_NID (X509_get_subject_name (peercert),
-                             NID_commonName, cert_CN, sizeof (cert_CN));
-
-  dprint (2, (debugfile, "check_certificate_hostname: cert=[%s] host=[%s]\n",
-              cert_CN, host));
-
-  return strcmp (cert_CN, host) == 0;
+/* port to mutt from msmtp's tls.c */
+static int hostname_match (const char *hostname, const char *certname)
+{
+  const char *cmp1, *cmp2;
+
+  if (strncmp(certname, "*.", 2) == 0)
+  {
+    cmp1 = certname + 2;
+    cmp2 = strchr(hostname, '.');
+    if (!cmp2)
+    {
+      return 0;
+    }
+    else
+    {
+      cmp2++;
+    }
+  }
+  else
+  {
+    cmp1 = certname;
+    cmp2 = hostname;
+  }
+
+  if (*cmp1 == '\0' || *cmp2 == '\0')
+  {
+    return 0;
+  }
+
+  if (strcasecmp(cmp1, cmp2) != 0)
+  {
+    return 0;
+  }
+
+  return 1;
+}
+
+/* port to mutt from msmtp's tls.c */
+static int check_host (X509 *x509cert, const char *hostname, char *err, size_t errlen)
+{
+  int i, rc = 0;
+  /* hostname in ASCII format: */
+  char *hostname_ascii = NULL;
+  /* needed to get the common name: */
+  X509_NAME *x509_subject;
+  char *buf = NULL;
+  int bufsize;
+  /* needed to get the DNS subjectAltNames: */
+  STACK *subj_alt_names;
+  int subj_alt_names_count;
+  GENERAL_NAME *subj_alt_name;
+  /* did we find a name matching hostname? */
+  int match_found;
+
+  /* Check if 'hostname' matches the one of the subjectAltName extensions of
+   * type DNS or the Common Name (CN). */
+
+#ifdef HAVE_LIBIDN
+  if (idna_to_ascii_lz(hostname, &hostname_ascii, 0) != IDNA_SUCCESS)
+  {
+    hostname_ascii = safe_strdup(hostname);
+  }
+#else
+  hostname_ascii = safe_strdup(hostname);
+#endif
+
+  /* Try the DNS subjectAltNames. */
+  match_found = 0;
+  if ((subj_alt_names = X509_get_ext_d2i(x509cert, NID_subject_alt_name,
+                                         NULL, NULL)))
+  {
+    subj_alt_names_count = sk_GENERAL_NAME_num(subj_alt_names);
+    for (i = 0; i < subj_alt_names_count; i++)
+    {
+      subj_alt_name = sk_GENERAL_NAME_value(subj_alt_names, i);
+      if (subj_alt_name->type == GEN_DNS)
+      {
+        if ((match_found = hostname_match(hostname_ascii,
+                                          (char *)(subj_alt_name->d.ia5->data))))
+        {
+          break;
+        }
+      }
+    }
+  }
+
+  if (!match_found)
+  {
+    /* Try the common name */
+    if (!(x509_subject = X509_get_subject_name(x509cert)))
+    {
+      if (err && errlen)
+        strfcpy (err, _("cannot get certificate subject"), errlen);
+      goto out;
+    }
+
+    bufsize = X509_NAME_get_text_by_NID(x509_subject, NID_commonName,
+                                        NULL, 0);
+    bufsize++;
+    buf = safe_malloc((size_t)bufsize);
+    if (X509_NAME_get_text_by_NID(x509_subject, NID_commonName,
+                                  buf, bufsize) == -1)
+    {
+      if (err && errlen)
+        strfcpy (err, _("cannot get certificate common name"), errlen);
+      goto out;
+    }
+    match_found = hostname_match(hostname_ascii, buf);
+  }
+
+  if (!match_found)
+  {
+    if (err && errlen)
+      snprintf (err, errlen, _("certificate owner does not match hostname %s"),
+                hostname);
+    goto out;
+  }
+
+  rc = 1;
+
+out:
+  FREE(&buf);
+  FREE(&hostname_ascii);
+
+  return rc;
 }
 
@@ -623 +736 @@
   }
 
-  if (check_certificate_hostname (data->cert, conn->account.host))
+  buf[0] = 0;
+  if (check_host (data->cert, conn->account.host, buf, sizeof (buf)))
   {
     dprint (1, (debugfile, "ssl_check_certificate: hostname check passed\n"));
   }
   else
+  {
+    mutt_error (_("Certificate host check failed: %s"), buf);
+    mutt_sleep (2);
     certerr_hostname = 1;
+  }
 
   if (!certerr_hostname && check_certificate_by_signer (data->cert))