Imported Upstream version 2.3_rc1

1 files changed, 1175 insertions, 0 deletions

diff --git a/src/openvpn/ssl_openssl.c b/src/openvpn/ssl_openssl.c
new file mode 100644
index 0000000..a727b60
--- /dev/null
+++ b/src/openvpn/ssl_openssl.c
@@ -0,0 +1,1175 @@
+/*
+ *  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 OpenSSL 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_OPENSSL)
+
+#include "errlevel.h"
+#include "buffer.h"
+#include "misc.h"
+#include "manage.h"
+#include "memdbg.h"
+#include "ssl_backend.h"
+#include "ssl_common.h"
+#include "base64.h"
+
+#ifdef ENABLE_CRYPTOAPI
+#include "cryptoapi.h"
+#endif
+
+#include "ssl_verify_openssl.h"
+
+#include <openssl/err.h>
+#include <openssl/pkcs12.h>
+#include <openssl/x509.h>
+#include <openssl/crypto.h>
+
+/*
+ * Allocate space in SSL objects in which to store a struct tls_session
+ * pointer back to parent.
+ *
+ */
+
+int mydata_index; /* GLOBAL */
+
+void
+tls_init_lib()
+{
+  SSL_library_init();
+#ifndef ENABLE_SMALL
+  SSL_load_error_strings();
+#endif
+  OpenSSL_add_all_algorithms ();
+
+  mydata_index = SSL_get_ex_new_index(0, "struct session *", NULL, NULL, NULL);
+  ASSERT (mydata_index >= 0);
+}
+
+void
+tls_free_lib()
+{
+  EVP_cleanup();
+#ifndef ENABLE_SMALL
+  ERR_free_strings();
+#endif
+}
+
+void
+tls_clear_error()
+{
+  ERR_clear_error ();
+}
+
+/*
+ * OpenSSL callback to get a temporary RSA key, mostly
+ * used for export ciphers.
+ */
+static RSA *
+tmp_rsa_cb (SSL * s, int is_export, int keylength)
+{
+  static RSA *rsa_tmp = NULL;
+  if (rsa_tmp == NULL)
+    {
+      msg (D_HANDSHAKE, "Generating temp (%d bit) RSA key", keylength);
+      rsa_tmp = RSA_generate_key (keylength, RSA_F4, NULL, NULL);
+    }
+  return (rsa_tmp);
+}
+
+void
+tls_ctx_server_new(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+
+  ctx->ctx = SSL_CTX_new (TLSv1_server_method ());
+
+  if (ctx->ctx == NULL)
+    msg (M_SSLERR, "SSL_CTX_new TLSv1_server_method");
+
+  SSL_CTX_set_tmp_rsa_callback (ctx->ctx, tmp_rsa_cb);
+}
+
+void
+tls_ctx_client_new(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+
+  ctx->ctx = SSL_CTX_new (TLSv1_client_method ());
+
+  if (ctx->ctx == NULL)
+    msg (M_SSLERR, "SSL_CTX_new TLSv1_client_method");
+}
+
+void
+tls_ctx_free(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+  if (NULL != ctx->ctx)
+    SSL_CTX_free (ctx->ctx);
+  ctx->ctx = NULL;
+}
+
+bool tls_ctx_initialised(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+  return NULL != ctx->ctx;
+}
+
+/*
+ * Print debugging information on SSL/TLS session negotiation.
+ */
+
+#ifndef INFO_CALLBACK_SSL_CONST
+#define INFO_CALLBACK_SSL_CONST const
+#endif
+static void
+info_callback (INFO_CALLBACK_SSL_CONST SSL * s, int where, int ret)
+{
+  if (where & SSL_CB_LOOP)
+    {
+      dmsg (D_HANDSHAKE_VERBOSE, "SSL state (%s): %s",
+	   where & SSL_ST_CONNECT ? "connect" :
+	   where & SSL_ST_ACCEPT ? "accept" :
+	   "undefined", SSL_state_string_long (s));
+    }
+  else if (where & SSL_CB_ALERT)
+    {
+      dmsg (D_HANDSHAKE_VERBOSE, "SSL alert (%s): %s: %s",
+	   where & SSL_CB_READ ? "read" : "write",
+	   SSL_alert_type_string_long (ret),
+	   SSL_alert_desc_string_long (ret));
+    }
+}
+
+void
+tls_ctx_set_options (struct tls_root_ctx *ctx, unsigned int ssl_flags)
+{
+  ASSERT(NULL != ctx);
+
+  SSL_CTX_set_session_cache_mode (ctx->ctx, SSL_SESS_CACHE_OFF);
+  SSL_CTX_set_options (ctx->ctx, SSL_OP_SINGLE_DH_USE);
+  SSL_CTX_set_default_passwd_cb (ctx->ctx, pem_password_callback);
+
+  /* Require peer certificate verification */
+#if P2MP_SERVER
+  if (ssl_flags & SSLF_CLIENT_CERT_NOT_REQUIRED)
+    {
+      msg (M_WARN, "WARNING: POTENTIALLY DANGEROUS OPTION "
+	  "--client-cert-not-required may accept clients which do not present "
+	  "a certificate");
+    }
+  else
+#endif
+  SSL_CTX_set_verify (ctx->ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
+		      verify_callback);
+
+  SSL_CTX_set_info_callback (ctx->ctx, info_callback);
+}
+
+void
+tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
+{
+  ASSERT(NULL != ctx);
+
+  if(!SSL_CTX_set_cipher_list(ctx->ctx, ciphers))
+    msg(M_SSLERR, "Failed to set restricted TLS cipher list: %s", ciphers);
+}
+
+void
+tls_ctx_load_dh_params (struct tls_root_ctx *ctx, const char *dh_file,
+    const char *dh_file_inline
+    )
+{
+  DH *dh;
+  BIO *bio;
+
+  ASSERT(NULL != ctx);
+
+  if (!strcmp (dh_file, INLINE_FILE_TAG) && dh_file_inline)
+    {
+      if (!(bio = BIO_new_mem_buf ((char *)dh_file_inline, -1)))
+	msg (M_SSLERR, "Cannot open memory BIO for inline DH parameters");
+    }
+  else
+    {
+      /* Get Diffie Hellman Parameters */
+      if (!(bio = BIO_new_file (dh_file, "r")))
+	msg (M_SSLERR, "Cannot open %s for DH parameters", dh_file);
+    }
+
+  dh = PEM_read_bio_DHparams (bio, NULL, NULL, NULL);
+  BIO_free (bio);
+
+  if (!dh)
+    msg (M_SSLERR, "Cannot load DH parameters from %s", dh_file);
+  if (!SSL_CTX_set_tmp_dh (ctx->ctx, dh))
+    msg (M_SSLERR, "SSL_CTX_set_tmp_dh");
+
+  msg (D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with %d bit key",
+       8 * DH_size (dh));
+
+  DH_free (dh);
+}
+
+int
+tls_ctx_load_pkcs12(struct tls_root_ctx *ctx, const char *pkcs12_file,
+    const char *pkcs12_file_inline,
+    bool load_ca_file
+    )
+{
+  FILE *fp;
+  EVP_PKEY *pkey;
+  X509 *cert;
+  STACK_OF(X509) *ca = NULL;
+  PKCS12 *p12;
+  int i;
+  char password[256];
+
+  ASSERT(NULL != ctx);
+
+  if (!strcmp (pkcs12_file, INLINE_FILE_TAG) && pkcs12_file_inline)
+    {
+      BIO *b64 = BIO_new(BIO_f_base64());
+      BIO *bio = BIO_new_mem_buf((void *) pkcs12_file_inline,
+	  (int) strlen(pkcs12_file_inline));
+      ASSERT(b64 && bio);
+      BIO_push(b64, bio);
+      p12 = d2i_PKCS12_bio(b64, NULL);
+      if (!p12)
+	msg(M_SSLERR, "Error reading inline PKCS#12 file");
+      BIO_free(b64);
+      BIO_free(bio);
+    }
+  else
+    {
+      /* Load the PKCS #12 file */
+      if (!(fp = platform_fopen(pkcs12_file, "rb")))
+	msg(M_SSLERR, "Error opening file %s", pkcs12_file);
+      p12 = d2i_PKCS12_fp(fp, NULL);
+      fclose(fp);
+      if (!p12)
+	msg(M_SSLERR, "Error reading PKCS#12 file %s", pkcs12_file);
+    }
+
+  /* Parse the PKCS #12 file */
+  if (!PKCS12_parse(p12, "", &pkey, &cert, &ca))
+   {
+     pem_password_callback (password, sizeof(password) - 1, 0, NULL);
+     /* Reparse the PKCS #12 file with password */
+     ca = NULL;
+     if (!PKCS12_parse(p12, password, &pkey, &cert, &ca))
+      {
+#ifdef ENABLE_MANAGEMENT
+	      if (management && (ERR_GET_REASON (ERR_peek_error()) == PKCS12_R_MAC_VERIFY_FAILURE))
+		management_auth_failure (management, UP_TYPE_PRIVATE_KEY, NULL);
+#endif
+	PKCS12_free(p12);
+	return 1;
+      }
+   }
+  PKCS12_free(p12);
+
+  /* Load Certificate */
+  if (!SSL_CTX_use_certificate (ctx->ctx, cert))
+   msg (M_SSLERR, "Cannot use certificate");
+
+  /* Load Private Key */
+  if (!SSL_CTX_use_PrivateKey (ctx->ctx, pkey))
+   msg (M_SSLERR, "Cannot use private key");
+  warn_if_group_others_accessible (pkcs12_file);
+
+  /* Check Private Key */
+  if (!SSL_CTX_check_private_key (ctx->ctx))
+   msg (M_SSLERR, "Private key does not match the certificate");
+
+  /* Set Certificate Verification chain */
+  if (load_ca_file)
+   {
+     if (ca && sk_X509_num(ca))
+      {
+	for (i = 0; i < sk_X509_num(ca); i++)
+	  {
+	      if (!X509_STORE_add_cert(ctx->ctx->cert_store,sk_X509_value(ca, i)))
+	      msg (M_SSLERR, "Cannot add certificate to certificate chain (X509_STORE_add_cert)");
+	    if (!SSL_CTX_add_client_CA(ctx->ctx, sk_X509_value(ca, i)))
+	      msg (M_SSLERR, "Cannot add certificate to client CA list (SSL_CTX_add_client_CA)");
+	  }
+      }
+   }
+  return 0;
+}
+
+#ifdef ENABLE_CRYPTOAPI
+void
+tls_ctx_load_cryptoapi(struct tls_root_ctx *ctx, const char *cryptoapi_cert)
+{
+  ASSERT(NULL != ctx);
+
+  /* Load Certificate and Private Key */
+  if (!SSL_CTX_use_CryptoAPI_certificate (ctx->ctx, cryptoapi_cert))
+    msg (M_SSLERR, "Cannot load certificate \"%s\" from Microsoft Certificate Store",
+	   cryptoapi_cert);
+}
+#endif /* WIN32 */
+
+static void
+tls_ctx_add_extra_certs (struct tls_root_ctx *ctx, BIO *bio)
+{
+  X509 *cert;
+  for (;;)
+    {
+      cert = NULL;
+      if (!PEM_read_bio_X509 (bio, &cert, 0, NULL)) /* takes ownership of cert */
+        break;
+      if (!cert)
+        msg (M_SSLERR, "Error reading extra certificate");
+      if (SSL_CTX_add_extra_chain_cert(ctx->ctx, cert) != 1)
+        msg (M_SSLERR, "Error adding extra certificate");
+    }
+}
+
+void
+tls_ctx_load_cert_file (struct tls_root_ctx *ctx, const char *cert_file,
+    const char *cert_file_inline, X509 **x509
+    )
+{
+  BIO *in = NULL;
+  X509 *x = NULL;
+  int ret = 0;
+  bool inline_file = false;
+
+  ASSERT (NULL != ctx);
+  if (NULL != x509)
+    ASSERT (NULL == *x509);
+
+  inline_file = (strcmp (cert_file, INLINE_FILE_TAG) == 0);
+
+  if (inline_file && cert_file_inline)
+    in = BIO_new_mem_buf ((char *)cert_file_inline, -1);
+  else
+    in = BIO_new_file (cert_file, "r");
+
+  if (in == NULL)
+    {
+      SSLerr (SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_SYS_LIB);
+      goto end;
+    }
+
+  x = PEM_read_bio_X509 (in, NULL, ctx->ctx->default_passwd_callback,
+                         ctx->ctx->default_passwd_callback_userdata);
+  if (x == NULL)
+    {
+      SSLerr (SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_PEM_LIB);
+      goto end;
+    }
+
+  ret = SSL_CTX_use_certificate (ctx->ctx, x);
+  if (ret)
+    tls_ctx_add_extra_certs (ctx, in);
+
+end:
+  if (!ret)
+    {
+      if (inline_file)
+        msg (M_SSLERR, "Cannot load inline certificate file");
+      else
+        msg (M_SSLERR, "Cannot load certificate file %s", cert_file);
+    }
+
+  if (in != NULL)
+    BIO_free(in);
+  if (x509)
+    *x509 = x;
+  else if (x)
+    X509_free (x);
+}
+
+void
+tls_ctx_free_cert_file (X509 *x509)
+{
+  X509_free(x509);
+}
+
+int
+tls_ctx_load_priv_file (struct tls_root_ctx *ctx, const char *priv_key_file,
+    const char *priv_key_file_inline
+    )
+{
+  int status;
+  SSL_CTX *ssl_ctx = NULL;
+  BIO *in = NULL;
+  EVP_PKEY *pkey = NULL;
+  int ret = 1;
+
+  ASSERT(NULL != ctx);
+
+  ssl_ctx = ctx->ctx;
+
+  if (!strcmp (priv_key_file, INLINE_FILE_TAG) && priv_key_file_inline)
+    in = BIO_new_mem_buf ((char *)priv_key_file_inline, -1);
+  else
+    in = BIO_new_file (priv_key_file, "r");
+
+  if (!in)
+    goto end;
+
+  pkey = PEM_read_bio_PrivateKey (in, NULL,
+                                  ssl_ctx->default_passwd_callback,
+                                  ssl_ctx->default_passwd_callback_userdata);
+  if (!pkey)
+    goto end;
+
+  if (!SSL_CTX_use_PrivateKey (ssl_ctx, pkey))
+    {
+#ifdef ENABLE_MANAGEMENT
+      if (management && (ERR_GET_REASON (ERR_peek_error()) == EVP_R_BAD_DECRYPT))
+          management_auth_failure (management, UP_TYPE_PRIVATE_KEY, NULL);
+#endif
+      msg (M_WARN|M_SSL, "Cannot load private key file %s", priv_key_file);
+      goto end;
+    }
+  warn_if_group_others_accessible (priv_key_file);
+
+  /* Check Private Key */
+  if (!SSL_CTX_check_private_key (ssl_ctx))
+    msg (M_SSLERR, "Private key does not match the certificate");
+  ret = 0;
+
+end:
+  if (pkey)
+    EVP_PKEY_free (pkey);
+  if (in)
+    BIO_free (in);
+  return ret;
+}
+
+#ifdef MANAGMENT_EXTERNAL_KEY
+
+/* encrypt */
+static int
+rsa_pub_enc(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
+{
+  ASSERT(0);
+  return -1;
+}
+
+/* verify arbitrary data */
+static int
+rsa_pub_dec(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
+{
+  ASSERT(0);
+  return -1;
+}
+
+/* decrypt */
+static int
+rsa_priv_dec(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
+{
+  ASSERT(0);
+  return -1;
+}
+
+/* called at RSA_free */
+static int
+rsa_finish(RSA *rsa)
+{
+  free ((void*)rsa->meth);
+  rsa->meth = NULL;
+  return 1;
+}
+
+/* sign arbitrary data */
+static int
+rsa_priv_enc(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
+{
+  /* optional app data in rsa->meth->app_data; */
+  char *in_b64 = NULL;
+  char *out_b64 = NULL;
+  int ret = -1;
+  int len;
+
+  if (padding != RSA_PKCS1_PADDING)
+    {
+      RSAerr (RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
+      goto done;
+    }
+
+  /* convert 'from' to base64 */
+  if (openvpn_base64_encode (from, flen, &in_b64) <= 0)
+    goto done;
+
+  /* call MI for signature */
+  if (management)
+    out_b64 = management_query_rsa_sig (management, in_b64);
+  if (!out_b64)
+    goto done;
+
+  /* decode base64 signature to binary */
+  len = RSA_size(rsa);
+  ret = openvpn_base64_decode (out_b64, to, len);
+
+  /* verify length */
+  if (ret != len)
+    ret = -1;
+
+ done:
+  if (in_b64)
+    free (in_b64);
+  if (out_b64)
+    free (out_b64);
+  return ret;
+}
+
+int
+tls_ctx_use_external_private_key (struct tls_root_ctx *ctx, X509 *cert)
+{
+  RSA *rsa = NULL;
+  RSA *pub_rsa;
+  RSA_METHOD *rsa_meth;
+
+  ASSERT (NULL != ctx);
+  ASSERT (NULL != cert);
+
+  /* allocate custom RSA method object */
+  ALLOC_OBJ_CLEAR (rsa_meth, RSA_METHOD);
+  rsa_meth->name = "OpenVPN external private key RSA Method";
+  rsa_meth->rsa_pub_enc = rsa_pub_enc;
+  rsa_meth->rsa_pub_dec = rsa_pub_dec;
+  rsa_meth->rsa_priv_enc = rsa_priv_enc;
+  rsa_meth->rsa_priv_dec = rsa_priv_dec;
+  rsa_meth->init = NULL;
+  rsa_meth->finish = rsa_finish;
+  rsa_meth->flags = RSA_METHOD_FLAG_NO_CHECK;
+  rsa_meth->app_data = NULL;
+
+  /* allocate RSA object */
+  rsa = RSA_new();
+  if (rsa == NULL)
+    {
+      SSLerr(SSL_F_SSL_USE_PRIVATEKEY, ERR_R_MALLOC_FAILURE);
+      goto err;
+    }
+
+  /* get the public key */
+  ASSERT(cert->cert_info->key->pkey); /* NULL before SSL_CTX_use_certificate() is called */
+  pub_rsa = cert->cert_info->key->pkey->pkey.rsa;
+
+  /* initialize RSA object */
+  rsa->n = BN_dup(pub_rsa->n);
+  rsa->flags |= RSA_FLAG_EXT_PKEY;
+  if (!RSA_set_method(rsa, rsa_meth))
+    goto err;
+
+  /* bind our custom RSA object to ssl_ctx */
+  if (!SSL_CTX_use_RSAPrivateKey(ctx->ctx, rsa))
+    goto err;
+
+  RSA_free(rsa); /* doesn't necessarily free, just decrements refcount */
+  return 1;
+
+ err:
+  if (rsa)
+    RSA_free(rsa);
+  else
+    {
+      if (rsa_meth)
+	free(rsa_meth);
+    }
+  msg (M_SSLERR, "Cannot enable SSL external private key capability");
+  return 0;
+}
+
+#endif
+
+static int
+sk_x509_name_cmp(const X509_NAME * const *a, const X509_NAME * const *b)
+{
+  return X509_NAME_cmp (*a, *b);
+}
+
+void
+tls_ctx_load_ca (struct tls_root_ctx *ctx, const char *ca_file,
+    const char *ca_file_inline,
+    const char *ca_path, bool tls_server
+    )
+{
+  STACK_OF(X509_INFO) *info_stack = NULL;
+  STACK_OF(X509_NAME) *cert_names = NULL;
+  X509_LOOKUP *lookup = NULL;
+  X509_STORE *store = NULL;
+  X509_NAME *xn = NULL;
+  BIO *in = NULL;
+  int i, added = 0;
+
+  ASSERT(NULL != ctx);
+
+  store = SSL_CTX_get_cert_store(ctx->ctx);
+  if (!store)
+    msg(M_SSLERR, "Cannot get certificate store (SSL_CTX_get_cert_store)");
+
+  /* Try to add certificates and CRLs from ca_file */
+  if (ca_file)
+    {
+      if (!strcmp (ca_file, INLINE_FILE_TAG) && ca_file_inline)
+        in = BIO_new_mem_buf ((char *)ca_file_inline, -1);
+      else
+        in = BIO_new_file (ca_file, "r");
+
+      if (in)
+        info_stack = PEM_X509_INFO_read_bio (in, NULL, NULL, NULL);
+
+      if (info_stack)
+        {
+          for (i = 0; i < sk_X509_INFO_num (info_stack); i++)
+            {
+              X509_INFO *info = sk_X509_INFO_value (info_stack, i);
+              if (info->crl)
+                  X509_STORE_add_crl (store, info->crl);
+
+              if (info->x509)
+                {
+                  X509_STORE_add_cert (store, info->x509);
+                  added++;
+
+                  if (!tls_server)
+                    continue;
+
+                  /* Use names of CAs as a client CA list */
+                  if (cert_names == NULL)
+                    {
+                      cert_names = sk_X509_NAME_new (sk_x509_name_cmp);
+                      if (!cert_names)
+                        continue;
+                    }
+
+                  xn = X509_get_subject_name (info->x509);
+                  if (!xn)
+                    continue;
+
+                  /* Don't add duplicate CA names */
+                  if (sk_X509_NAME_find (cert_names, xn) == -1)
+                    {
+                      xn = X509_NAME_dup (xn);
+                      if (!xn)
+                        continue;
+                      sk_X509_NAME_push (cert_names, xn);
+                    }
+                }
+            }
+          sk_X509_INFO_pop_free (info_stack, X509_INFO_free);
+        }
+
+      if (tls_server)
+        SSL_CTX_set_client_CA_list (ctx->ctx, cert_names);
+
+      if (!added || (tls_server && sk_X509_NAME_num (cert_names) != added))
+        msg (M_SSLERR, "Cannot load CA certificate file %s", np(ca_file));
+      if (in)
+        BIO_free (in);
+    }
+
+  /* Set a store for certs (CA & CRL) with a lookup on the "capath" hash directory */
+  if (ca_path)
+    {
+      lookup = X509_STORE_add_lookup (store, X509_LOOKUP_hash_dir ());
+      if (lookup && X509_LOOKUP_add_dir (lookup, ca_path, X509_FILETYPE_PEM))
+        msg(M_WARN, "WARNING: experimental option --capath %s", ca_path);
+      else
+        msg(M_SSLERR, "Cannot add lookup at --capath %s", ca_path);
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+      X509_STORE_set_flags (store, X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL);
+#else
+      msg(M_WARN, "WARNING: this version of OpenSSL cannot handle CRL files in capath");
+#endif
+    }
+}
+
+void
+tls_ctx_load_extra_certs (struct tls_root_ctx *ctx, const char *extra_certs_file,
+    const char *extra_certs_file_inline
+    )
+{
+  BIO *in;
+  if (!strcmp (extra_certs_file, INLINE_FILE_TAG) && extra_certs_file_inline)
+    in = BIO_new_mem_buf ((char *)extra_certs_file_inline, -1);
+  else
+    in = BIO_new_file (extra_certs_file, "r");
+
+  if (in == NULL)
+    msg (M_SSLERR, "Cannot load extra-certs file: %s", extra_certs_file);
+  else
+    tls_ctx_add_extra_certs (ctx, in);
+
+  BIO_free (in);
+}
+
+/* **************************************
+ *
+ * Key-state specific functions
+ *
+ ***************************************/
+/*
+ *
+ * BIO functions
+ *
+ */
+
+#ifdef BIO_DEBUG
+
+#warning BIO_DEBUG defined
+
+static FILE *biofp;                            /* GLOBAL */
+static bool biofp_toggle;                      /* GLOBAL */
+static time_t biofp_last_open;                 /* GLOBAL */
+static const int biofp_reopen_interval = 600;  /* GLOBAL */
+
+static void
+close_biofp()
+{
+  if (biofp)
+    {
+      ASSERT (!fclose (biofp));
+      biofp = NULL;
+    }
+}
+
+static void
+open_biofp()
+{
+  const time_t current = time (NULL);
+  const pid_t pid = getpid ();
+
+  if (biofp_last_open + biofp_reopen_interval < current)
+    close_biofp();
+  if (!biofp)
+    {
+      char fn[256];
+      openvpn_snprintf(fn, sizeof(fn), "bio/%d-%d.log", pid, biofp_toggle);
+      biofp = fopen (fn, "w");
+      ASSERT (biofp);
+      biofp_last_open = time (NULL);
+      biofp_toggle ^= 1;
+    }
+}
+
+static void
+bio_debug_data (const char *mode, BIO *bio, const uint8_t *buf, int len, const char *desc)
+{
+  struct gc_arena gc = gc_new ();
+  if (len > 0)
+    {
+      open_biofp();
+      fprintf(biofp, "BIO_%s %s time=" time_format " bio=" ptr_format " len=%d data=%s\n",
+	      mode, desc, time (NULL), (ptr_type)bio, len, format_hex (buf, len, 0, &gc));
+      fflush (biofp);
+    }
+  gc_free (&gc);
+}
+
+static void
+bio_debug_oc (const char *mode, BIO *bio)
+{
+  open_biofp();
+  fprintf(biofp, "BIO %s time=" time_format " bio=" ptr_format "\n",
+	  mode, time (NULL), (ptr_type)bio);
+  fflush (biofp);
+}
+
+#endif
+
+/*
+ * OpenVPN's interface to SSL/TLS authentication,
+ * encryption, and decryption is exclusively
+ * through "memory BIOs".
+ */
+static BIO *
+getbio (BIO_METHOD * type, const char *desc)
+{
+  BIO *ret;
+  ret = BIO_new (type);
+  if (!ret)
+    msg (M_SSLERR, "Error creating %s BIO", desc);
+  return ret;
+}
+
+/*
+ * Write to an OpenSSL BIO in non-blocking mode.
+ */
+static int
+bio_write (BIO *bio, const uint8_t *data, int size, const char *desc)
+{
+  int i;
+  int ret = 0;
+  ASSERT (size >= 0);
+  if (size)
+    {
+      /*
+       * Free the L_TLS lock prior to calling BIO routines
+       * so that foreground thread can still call
+       * tls_pre_decrypt or tls_pre_encrypt,
+       * allowing tunnel packet forwarding to continue.
+       */
+#ifdef BIO_DEBUG
+      bio_debug_data ("write", bio, data, size, desc);
+#endif
+      i = BIO_write (bio, data, size);
+
+      if (i < 0)
+	{
+	  if (BIO_should_retry (bio))
+	    {
+	      ;
+	    }
+	  else
+	    {
+	      msg (D_TLS_ERRORS | M_SSL, "TLS ERROR: BIO write %s error",
+		   desc);
+	      ret = -1;
+	      ERR_clear_error ();
+	    }
+	}
+      else if (i != size)
+	{
+	  msg (D_TLS_ERRORS | M_SSL,
+	       "TLS ERROR: BIO write %s incomplete %d/%d", desc, i, size);
+	  ret = -1;
+	  ERR_clear_error ();
+	}
+      else
+	{			/* successful write */
+	  dmsg (D_HANDSHAKE_VERBOSE, "BIO write %s %d bytes", desc, i);
+	  ret = 1;
+	}
+    }
+  return ret;
+}
+
+/*
+ * Inline functions for reading from and writing
+ * to BIOs.
+ */
+
+static void
+bio_write_post (const int status, struct buffer *buf)
+{
+  if (status == 1) /* success status return from bio_write? */
+    {
+      memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
+      buf->len = 0;
+    }
+}
+
+/*
+ * Read from an OpenSSL BIO in non-blocking mode.
+ */
+static int
+bio_read (BIO *bio, struct buffer *buf, int maxlen, const char *desc)
+{
+  int i;
+  int ret = 0;
+  ASSERT (buf->len >= 0);
+  if (buf->len)
+    {
+      ;
+    }
+  else
+    {
+      int len = buf_forward_capacity (buf);
+      if (maxlen < len)
+	len = maxlen;
+
+      /*
+       * BIO_read brackets most of the serious RSA
+       * key negotiation number crunching.
+       */
+      i = BIO_read (bio, BPTR (buf), len);
+
+      VALGRIND_MAKE_READABLE ((void *) &i, sizeof (i));
+
+#ifdef BIO_DEBUG
+      bio_debug_data ("read", bio, BPTR (buf), i, desc);
+#endif
+      if (i < 0)
+	{
+	  if (BIO_should_retry (bio))
+	    {
+	      ;
+	    }
+	  else
+	    {
+	      msg (D_TLS_ERRORS | M_SSL, "TLS_ERROR: BIO read %s error",
+		   desc);
+	      buf->len = 0;
+	      ret = -1;
+	      ERR_clear_error ();
+	    }
+	}
+      else if (!i)
+	{
+	  buf->len = 0;
+	}
+      else
+	{			/* successful read */
+	  dmsg (D_HANDSHAKE_VERBOSE, "BIO read %s %d bytes", desc, i);
+	  buf->len = i;
+	  ret = 1;
+	  VALGRIND_MAKE_READABLE ((void *) BPTR (buf), BLEN (buf));
+	}
+    }
+  return ret;
+}
+
+void
+key_state_ssl_init(struct key_state_ssl *ks_ssl, const struct tls_root_ctx *ssl_ctx, bool is_server, void *session)
+{
+  ASSERT(NULL != ssl_ctx);
+  ASSERT(ks_ssl);
+  CLEAR (*ks_ssl);
+
+  ks_ssl->ssl = SSL_new (ssl_ctx->ctx);
+  if (!ks_ssl->ssl)
+    msg (M_SSLERR, "SSL_new failed");
+
+  /* put session * in ssl object so we can access it
+     from verify callback*/
+  SSL_set_ex_data (ks_ssl->ssl, mydata_index, session);
+
+  ks_ssl->ssl_bio = getbio (BIO_f_ssl (), "ssl_bio");
+  ks_ssl->ct_in = getbio (BIO_s_mem (), "ct_in");
+  ks_ssl->ct_out = getbio (BIO_s_mem (), "ct_out");
+
+#ifdef BIO_DEBUG
+  bio_debug_oc ("open ssl_bio", ks_ssl->ssl_bio);
+  bio_debug_oc ("open ct_in", ks_ssl->ct_in);
+  bio_debug_oc ("open ct_out", ks_ssl->ct_out);
+#endif
+
+  if (is_server)
+    SSL_set_accept_state (ks_ssl->ssl);
+  else
+    SSL_set_connect_state (ks_ssl->ssl);
+
+  SSL_set_bio (ks_ssl->ssl, ks_ssl->ct_in, ks_ssl->ct_out);
+  BIO_set_ssl (ks_ssl->ssl_bio, ks_ssl->ssl, BIO_NOCLOSE);
+}
+
+void key_state_ssl_free(struct key_state_ssl *ks_ssl)
+{
+  if (ks_ssl->ssl) {
+#ifdef BIO_DEBUG
+    bio_debug_oc ("close ssl_bio", ks_ssl->ssl_bio);
+    bio_debug_oc ("close ct_in", ks_ssl->ct_in);
+    bio_debug_oc ("close ct_out", ks_ssl->ct_out);
+#endif
+    BIO_free_all(ks_ssl->ssl_bio);
+    SSL_free (ks_ssl->ssl);
+  }
+}
+
+int
+key_state_write_plaintext (struct key_state_ssl *ks_ssl, struct buffer *buf)
+{
+  int ret = 0;
+  perf_push (PERF_BIO_WRITE_PLAINTEXT);
+
+#ifdef ENABLE_CRYPTO_OPENSSL
+  ASSERT (NULL != ks_ssl);
+
+  ret = bio_write (ks_ssl->ssl_bio, BPTR(buf), BLEN(buf),
+      "tls_write_plaintext");
+  bio_write_post (ret, buf);
+#endif /* ENABLE_CRYPTO_OPENSSL */
+
+  perf_pop ();
+  return ret;
+}
+
+int
+key_state_write_plaintext_const (struct key_state_ssl *ks_ssl, const uint8_t *data, int len)
+{
+  int ret = 0;
+  perf_push (PERF_BIO_WRITE_PLAINTEXT);
+
+  ASSERT (NULL != ks_ssl);
+
+  ret = bio_write (ks_ssl->ssl_bio, data, len, "tls_write_plaintext_const");
+
+  perf_pop ();
+  return ret;
+}
+
+int
+key_state_read_ciphertext (struct key_state_ssl *ks_ssl, struct buffer *buf,
+    int maxlen)
+{
+  int ret = 0;
+  perf_push (PERF_BIO_READ_CIPHERTEXT);
+
+  ASSERT (NULL != ks_ssl);
+
+  ret = bio_read (ks_ssl->ct_out, buf, maxlen, "tls_read_ciphertext");
+
+  perf_pop ();
+  return ret;
+}
+
+int
+key_state_write_ciphertext (struct key_state_ssl *ks_ssl, struct buffer *buf)
+{
+  int ret = 0;
+  perf_push (PERF_BIO_WRITE_CIPHERTEXT);
+
+  ASSERT (NULL != ks_ssl);
+
+  ret = bio_write (ks_ssl->ct_in, BPTR(buf), BLEN(buf), "tls_write_ciphertext");
+  bio_write_post (ret, buf);
+
+  perf_pop ();
+  return ret;
+}
+
+int
+key_state_read_plaintext (struct key_state_ssl *ks_ssl, struct buffer *buf,
+    int maxlen)
+{
+  int ret = 0;
+  perf_push (PERF_BIO_READ_PLAINTEXT);
+
+  ASSERT (NULL != ks_ssl);
+
+  ret = bio_read (ks_ssl->ssl_bio, buf, maxlen, "tls_read_plaintext");
+
+  perf_pop ();
+  return ret;
+}
+
+/* **************************************
+ *
+ * Information functions
+ *
+ * Print information for the end user.
+ *
+ ***************************************/
+void
+print_details (struct key_state_ssl * ks_ssl, const char *prefix)
+{
+  const SSL_CIPHER *ciph;
+  X509 *cert;
+  char s1[256];
+  char s2[256];
+
+  s1[0] = s2[0] = 0;
+  ciph = SSL_get_current_cipher (ks_ssl->ssl);
+  openvpn_snprintf (s1, sizeof (s1), "%s %s, cipher %s %s",
+		    prefix,
+		    SSL_get_version (ks_ssl->ssl),
+		    SSL_CIPHER_get_version (ciph),
+		    SSL_CIPHER_get_name (ciph));
+  cert = SSL_get_peer_certificate (ks_ssl->ssl);
+  if (cert != NULL)
+    {
+      EVP_PKEY *pkey = X509_get_pubkey (cert);
+      if (pkey != NULL)
+	{
+	  if (pkey->type == EVP_PKEY_RSA && pkey->pkey.rsa != NULL
+	      && pkey->pkey.rsa->n != NULL)
+	    {
+	      openvpn_snprintf (s2, sizeof (s2), ", %d bit RSA",
+				BN_num_bits (pkey->pkey.rsa->n));
+	    }
+	  else if (pkey->type == EVP_PKEY_DSA && pkey->pkey.dsa != NULL
+		   && pkey->pkey.dsa->p != NULL)
+	    {
+	      openvpn_snprintf (s2, sizeof (s2), ", %d bit DSA",
+				BN_num_bits (pkey->pkey.dsa->p));
+	    }
+	  EVP_PKEY_free (pkey);
+	}
+      X509_free (cert);
+    }
+  /* The SSL API does not allow us to look at temporary RSA/DH keys,
+   * otherwise we should print their lengths too */
+  msg (D_HANDSHAKE, "%s%s", s1, s2);
+}
+
+void
+show_available_tls_ciphers ()
+{
+  SSL_CTX *ctx;
+  SSL *ssl;
+  const char *cipher_name;
+  int priority = 0;
+
+  ctx = SSL_CTX_new (TLSv1_method ());
+  if (!ctx)
+    msg (M_SSLERR, "Cannot create SSL_CTX object");
+
+  ssl = SSL_new (ctx);
+  if (!ssl)
+    msg (M_SSLERR, "Cannot create SSL object");
+
+  printf ("Available TLS Ciphers,\n");
+  printf ("listed in order of preference:\n\n");
+  while ((cipher_name = SSL_get_cipher_list (ssl, priority++)))
+    printf ("%s\n", cipher_name);
+  printf ("\n");
+
+  SSL_free (ssl);
+  SSL_CTX_free (ctx);
+}
+
+void
+get_highest_preference_tls_cipher (char *buf, int size)
+{
+  SSL_CTX *ctx;
+  SSL *ssl;
+  const char *cipher_name;
+
+  ctx = SSL_CTX_new (TLSv1_method ());
+  if (!ctx)
+    msg (M_SSLERR, "Cannot create SSL_CTX object");
+  ssl = SSL_new (ctx);
+  if (!ssl)
+    msg (M_SSLERR, "Cannot create SSL object");
+
+  cipher_name = SSL_get_cipher_list (ssl, 0);
+  strncpynt (buf, cipher_name, size);
+
+  SSL_free (ssl);
+  SSL_CTX_free (ctx);
+}
+
+#endif /* defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_OPENSSL) */