Imported Upstream version 2.3_rc1

1 files changed, 409 insertions, 0 deletions

diff --git a/src/openvpn/ssl_verify_polarssl.c b/src/openvpn/ssl_verify_polarssl.c
new file mode 100644
index 0000000..a32db8d
--- /dev/null
+++ b/src/openvpn/ssl_verify_polarssl.c
@@ -0,0 +1,409 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single TCP/UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ *  Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/**
+ * @file Control Channel Verification Module PolarSSL backend
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL)
+
+#include "ssl_verify.h"
+#include <polarssl/sha1.h>
+
+#define MAX_SUBJECT_LENGTH 256
+
+int
+verify_callback (void *session_obj, x509_cert *cert, int cert_depth,
+    int preverify_ok)
+{
+  struct tls_session *session = (struct tls_session *) session_obj;
+  struct gc_arena gc = gc_new();
+  int ret = 1;
+
+  ASSERT (cert);
+  ASSERT (session);
+
+  session->verified = false;
+
+  /* Remember certificate hash */
+  cert_hash_remember (session, cert_depth, x509_get_sha1_hash(cert, &gc));
+
+  /* did peer present cert which was signed by our root cert? */
+  if (!preverify_ok)
+    {
+      char *subject = x509_get_subject(cert, &gc);
+
+      if (subject)
+	msg (D_TLS_ERRORS, "VERIFY ERROR: depth=%d, %s", cert_depth, subject);
+      else
+	msg (D_TLS_ERRORS, "VERIFY ERROR: depth=%d, could not extract X509 "
+	      "subject string from certificate", cert_depth);
+
+      goto cleanup;
+    }
+
+  if (SUCCESS != verify_cert(session, cert, cert_depth))
+    goto cleanup;
+
+  ret = 0;
+
+cleanup:
+  gc_free(&gc);
+
+  /*
+   * PolarSSL expects 1 on failure, 0 on success
+   */
+  return ret;
+}
+
+#ifdef ENABLE_X509ALTUSERNAME
+# warning "X509 alt user name not yet supported for PolarSSL"
+#endif
+
+result_t
+x509_get_username (char *cn, int cn_len,
+    char *x509_username_field, x509_cert *cert)
+{
+  x509_name *name;
+
+  ASSERT( cn != NULL );
+
+  name = &cert->subject;
+
+  /* Find common name */
+  while( name != NULL )
+  {
+      if( memcmp( name->oid.p, OID_CN, OID_SIZE(OID_CN) ) == 0)
+	break;
+
+      name = name->next;
+  }
+
+  /* Not found, return an error if this is the peer's certificate */
+  if( name == NULL )
+      return FAILURE;
+
+  /* Found, extract CN */
+  if (cn_len > name->val.len)
+    memcpy( cn, name->val.p, name->val.len );
+  else
+    {
+      memcpy( cn, name->val.p, cn_len);
+      cn[cn_len-1] = '\0';
+    }
+
+  return SUCCESS;
+}
+
+char *
+x509_get_serial (x509_cert *cert, struct gc_arena *gc)
+{
+  int ret = 0;
+  int i = 0;
+  char *buf = NULL;
+  size_t len = cert->serial.len * 3 + 1;
+
+  buf = gc_malloc(len, true, gc);
+
+  if(x509parse_serial_gets(buf, len-1, &cert->serial) < 0)
+    buf = NULL;
+
+  return buf;
+}
+
+unsigned char *
+x509_get_sha1_hash (x509_cert *cert, struct gc_arena *gc)
+{
+  unsigned char *sha1_hash = gc_malloc(SHA_DIGEST_LENGTH, false, gc);
+  sha1(cert->tbs.p, cert->tbs.len, sha1_hash);
+  return sha1_hash;
+}
+
+char *
+x509_get_subject(x509_cert *cert, struct gc_arena *gc)
+{
+  char tmp_subject[MAX_SUBJECT_LENGTH] = {0};
+  char *subject = NULL;
+
+  int ret = 0;
+
+  ret = x509parse_dn_gets( tmp_subject, MAX_SUBJECT_LENGTH-1, &cert->subject );
+  if (ret > 0)
+    {
+      /* Allocate the required space for the subject */
+      subject = string_alloc(tmp_subject, gc);
+    }
+
+  return subject;
+}
+
+/*
+ * Save X509 fields to environment, using the naming convention:
+ *
+ * X509_{cert_depth}_{name}={value}
+ */
+void
+x509_setenv (struct env_set *es, int cert_depth, openvpn_x509_cert_t *cert)
+{
+  int i;
+  unsigned char c;
+  const x509_name *name;
+  char s[128];
+
+  name = &cert->subject;
+
+  memset( s, 0, sizeof( s ) );
+
+  while( name != NULL )
+    {
+      char name_expand[64+8];
+
+      if( name->oid.len == 2 && memcmp( name->oid.p, OID_X520, 2 ) == 0 )
+	{
+	  switch( name->oid.p[2] )
+	    {
+	    case X520_COMMON_NAME:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_CN",
+		    cert_depth); break;
+
+	    case X520_COUNTRY:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_C",
+		    cert_depth); break;
+
+	    case X520_LOCALITY:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_L",
+		    cert_depth); break;
+
+	    case X520_STATE:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_ST",
+		    cert_depth); break;
+
+	    case X520_ORGANIZATION:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_O",
+		    cert_depth); break;
+
+	    case X520_ORG_UNIT:
+		openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_OU",
+		    cert_depth); break;
+
+	    default:
+		openvpn_snprintf (name_expand, sizeof(name_expand),
+		    "X509_%d_0x%02X", cert_depth, name->oid.p[2]);
+		break;
+	    }
+	}
+	else if( name->oid.len == 8 && memcmp( name->oid.p, OID_PKCS9, 8 ) == 0 )
+	  {
+	    switch( name->oid.p[8] )
+	      {
+		case PKCS9_EMAIL:
+		  openvpn_snprintf (name_expand, sizeof(name_expand),
+		      "X509_%d_emailAddress", cert_depth); break;
+
+		default:
+		  openvpn_snprintf (name_expand, sizeof(name_expand),
+		      "X509_%d_0x%02X", cert_depth, name->oid.p[8]);
+		  break;
+	      }
+	  }
+	else
+	  {
+	    openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_\?\?",
+		cert_depth);
+	  }
+
+	for( i = 0; i < name->val.len; i++ )
+	{
+	    if( i >= (int) sizeof( s ) - 1 )
+		break;
+
+	    c = name->val.p[i];
+	    if( c < 32 || c == 127 || ( c > 128 && c < 160 ) )
+		 s[i] = '?';
+	    else s[i] = c;
+	}
+	s[i] = '\0';
+
+	/* Check both strings, set environment variable */
+	string_mod (name_expand, CC_PRINT, CC_CRLF, '_');
+	string_mod ((char*)s, CC_PRINT, CC_CRLF, '_');
+	setenv_str (es, name_expand, (char*)s);
+
+	name = name->next;
+    }
+}
+
+result_t
+x509_verify_ns_cert_type(const x509_cert *cert, const int usage)
+{
+  if (usage == NS_CERT_CHECK_NONE)
+    return SUCCESS;
+  if (usage == NS_CERT_CHECK_CLIENT)
+    return ((cert->ext_types & EXT_NS_CERT_TYPE)
+	&& (cert->ns_cert_type & NS_CERT_TYPE_SSL_CLIENT)) ? SUCCESS : FAILURE;
+  if (usage == NS_CERT_CHECK_SERVER)
+    return ((cert->ext_types & EXT_NS_CERT_TYPE)
+	&& (cert->ns_cert_type & NS_CERT_TYPE_SSL_SERVER)) ? SUCCESS : FAILURE;
+
+  return FAILURE;
+}
+
+result_t
+x509_verify_cert_ku (x509_cert *cert, const unsigned * const expected_ku,
+    int expected_len)
+{
+  result_t fFound = FAILURE;
+
+  if(!(cert->ext_types & EXT_KEY_USAGE))
+    {
+      msg (D_HANDSHAKE, "Certificate does not have key usage extension");
+    }
+  else
+    {
+      int i;
+      unsigned nku = cert->key_usage;
+
+      msg (D_HANDSHAKE, "Validating certificate key usage");
+      for (i=0; SUCCESS != fFound && i<expected_len; i++)
+	{
+	  if (expected_ku[i] != 0)
+	    {
+	      msg (D_HANDSHAKE, "++ Certificate has key usage  %04x, expects "
+		  "%04x", nku, expected_ku[i]);
+
+	      if (nku == expected_ku[i])
+		{
+		  fFound = SUCCESS;
+		}
+	    }
+	}
+    }
+  return fFound;
+}
+
+result_t
+x509_verify_cert_eku (x509_cert *cert, const char * const expected_oid)
+{
+  result_t fFound = FAILURE;
+
+  if (!(cert->ext_types & EXT_EXTENDED_KEY_USAGE))
+    {
+      msg (D_HANDSHAKE, "Certificate does not have extended key usage extension");
+    }
+  else
+    {
+      x509_sequence *oid_seq = &(cert->ext_key_usage);
+
+      msg (D_HANDSHAKE, "Validating certificate extended key usage");
+      while (oid_seq != NULL)
+	{
+	  x509_buf *oid = &oid_seq->buf;
+	  char oid_num_str[1024];
+	  const char *oid_str;
+
+	  oid_str = x509_oid_get_description(oid);
+	  if (oid_str != NULL)
+	    {
+	      msg (D_HANDSHAKE, "++ Certificate has EKU (str) %s, expects %s",
+		  oid_str, expected_oid);
+	      if (!strcmp (expected_oid, oid_str))
+		{
+		  fFound = SUCCESS;
+		  break;
+		}
+	    }
+
+	  if (0 == x509_oid_get_numeric_string( oid_num_str,
+	      sizeof (oid_num_str), oid))
+	    {
+	      msg (D_HANDSHAKE, "++ Certificate has EKU (oid) %s, expects %s",
+		  oid_num_str, expected_oid);
+	      if (!strcmp (expected_oid, oid_num_str))
+		{
+		  fFound = SUCCESS;
+		  break;
+		}
+	    }
+	  oid_seq = oid_seq->next;
+	}
+    }
+
+    return fFound;
+}
+
+result_t
+x509_write_pem(FILE *peercert_file, x509_cert *peercert)
+{
+    msg (M_WARN, "PolarSSL does not support writing peer certificate in PEM format");
+    return FAILURE;
+}
+
+/*
+ * check peer cert against CRL
+ */
+result_t
+x509_verify_crl(const char *crl_file, x509_cert *cert, const char *subject)
+{
+  result_t retval = FAILURE;
+  x509_crl crl = {0};
+
+  if (x509parse_crlfile(&crl, crl_file) != 0)
+    {
+      msg (M_ERR, "CRL: cannot read CRL from file %s", crl_file);
+      goto end;
+    }
+
+  if(cert->issuer_raw.len != crl.issuer_raw.len ||
+      memcmp(crl.issuer_raw.p, cert->issuer_raw.p, crl.issuer_raw.len) != 0)
+    {
+      msg (M_WARN, "CRL: CRL %s is from a different issuer than the issuer of "
+	  "certificate %s", crl_file, subject);
+      retval = SUCCESS;
+      goto end;
+    }
+
+  if (0 != x509parse_revoked(cert, &crl))
+    {
+      msg (D_HANDSHAKE, "CRL CHECK FAILED: %s is REVOKED", subject);
+      goto end;
+    }
+
+  retval = SUCCESS;
+  msg (D_HANDSHAKE, "CRL CHECK OK: %s",subject);
+
+end:
+  x509_crl_free(&crl);
+  return retval;
+}
+
+#endif /* #if defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL) */