Imported Upstream version 2.3_rc1

1 files changed, 870 insertions, 0 deletions

diff --git a/src/openvpn/ssl_polarssl.c b/src/openvpn/ssl_polarssl.c
new file mode 100644
index 0000000..12318b3
--- /dev/null
+++ b/src/openvpn/ssl_polarssl.c
@@ -0,0 +1,870 @@
+/*
+ *  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 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 "errlevel.h"
+#include "ssl_backend.h"
+#include "buffer.h"
+#include "misc.h"
+#include "manage.h"
+#include "ssl_common.h"
+
+#include <polarssl/sha2.h>
+#include <polarssl/havege.h>
+
+#include "ssl_verify_polarssl.h"
+#include <polarssl/pem.h>
+
+void
+tls_init_lib()
+{
+}
+
+void
+tls_free_lib()
+{
+}
+
+void
+tls_clear_error()
+{
+}
+
+static int default_ciphersuites[] =
+{
+    SSL_EDH_RSA_AES_256_SHA,
+    SSL_EDH_RSA_CAMELLIA_256_SHA,
+    SSL_EDH_RSA_AES_128_SHA,
+    SSL_EDH_RSA_CAMELLIA_128_SHA,
+    SSL_EDH_RSA_DES_168_SHA,
+    SSL_RSA_AES_256_SHA,
+    SSL_RSA_CAMELLIA_256_SHA,
+    SSL_RSA_AES_128_SHA,
+    SSL_RSA_CAMELLIA_128_SHA,
+    SSL_RSA_DES_168_SHA,
+    SSL_RSA_RC4_128_SHA,
+    SSL_RSA_RC4_128_MD5,
+    0
+};
+
+void
+tls_ctx_server_new(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+  CLEAR(*ctx);
+
+  ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
+  ALLOC_OBJ_CLEAR(ctx->priv_key, rsa_context);
+
+  ALLOC_OBJ_CLEAR(ctx->ca_chain, x509_cert);
+  ALLOC_OBJ_CLEAR(ctx->crt_chain, x509_cert);
+
+
+  ctx->endpoint = SSL_IS_SERVER;
+  ctx->initialised = true;
+}
+
+void
+tls_ctx_client_new(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+  CLEAR(*ctx);
+
+  ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
+  ALLOC_OBJ_CLEAR(ctx->priv_key, rsa_context);
+
+  ALLOC_OBJ_CLEAR(ctx->ca_chain, x509_cert);
+  ALLOC_OBJ_CLEAR(ctx->crt_chain, x509_cert);
+
+  ctx->endpoint = SSL_IS_CLIENT;
+  ctx->initialised = true;
+}
+
+void
+tls_ctx_free(struct tls_root_ctx *ctx)
+{
+  if (ctx)
+    {
+      rsa_free(ctx->priv_key);
+      free(ctx->priv_key);
+
+      x509_free(ctx->ca_chain);
+      free(ctx->ca_chain);
+
+      x509_free(ctx->crt_chain);
+      free(ctx->crt_chain);
+
+      dhm_free(ctx->dhm_ctx);
+      free(ctx->dhm_ctx);
+
+#if defined(ENABLE_PKCS11)
+      if (ctx->priv_key_pkcs11 != NULL) {
+	  pkcs11_priv_key_free(ctx->priv_key_pkcs11);
+	  free(ctx->priv_key_pkcs11);
+      }
+#endif
+
+      if (ctx->allowed_ciphers)
+	free(ctx->allowed_ciphers);
+
+      CLEAR(*ctx);
+
+      ctx->initialised = false;
+
+    }
+}
+
+bool
+tls_ctx_initialised(struct tls_root_ctx *ctx)
+{
+  ASSERT(NULL != ctx);
+  return ctx->initialised;
+}
+
+void
+tls_ctx_set_options (struct tls_root_ctx *ctx, unsigned int ssl_flags)
+{
+}
+
+void
+tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
+{
+  char *tmp_ciphers, *tmp_ciphers_orig, *token;
+  int i, cipher_count;
+  int ciphers_len = strlen (ciphers);
+
+  ASSERT (NULL != ctx);
+  ASSERT (0 != ciphers_len);
+
+  /* Get number of ciphers */
+  for (i = 0, cipher_count = 1; i < ciphers_len; i++)
+    if (ciphers[i] == ':')
+      cipher_count++;
+
+  /* Allocate an array for them */
+  ALLOC_ARRAY_CLEAR(ctx->allowed_ciphers, int, cipher_count+1)
+
+  /* Parse allowed ciphers, getting IDs */
+  i = 0;
+  tmp_ciphers_orig = tmp_ciphers = strdup(ciphers);
+
+  token = strtok (tmp_ciphers, ":");
+  while(token)
+    {
+      ctx->allowed_ciphers[i] = ssl_get_ciphersuite_id (token);
+      if (0 != ctx->allowed_ciphers[i])
+	i++;
+      token = strtok (NULL, ":");
+    }
+  free(tmp_ciphers_orig);
+}
+
+void
+tls_ctx_load_dh_params (struct tls_root_ctx *ctx, const char *dh_file,
+    const char *dh_file_inline
+    )
+{
+  if (!strcmp (dh_file, INLINE_FILE_TAG) && dh_file_inline)
+    {
+      if (0 != x509parse_dhm(ctx->dhm_ctx, dh_file_inline, strlen(dh_file_inline)))
+	msg (M_FATAL, "Cannot read inline DH parameters");
+  }
+else
+  {
+    if (0 != x509parse_dhmfile(ctx->dhm_ctx, dh_file))
+      msg (M_FATAL, "Cannot read DH parameters from file %s", dh_file);
+  }
+
+  msg (D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with " counter_format " bit key",
+      (counter_type) 8 * mpi_size(&ctx->dhm_ctx->P));
+}
+
+int
+tls_ctx_load_pkcs12(struct tls_root_ctx *ctx, const char *pkcs12_file,
+    const char *pkcs12_file_inline,
+    bool load_ca_file
+    )
+{
+  msg(M_FATAL, "PKCS #12 files not yet supported for PolarSSL.");
+  return 0;
+}
+
+#ifdef ENABLE_CRYPTOAPI
+void
+tls_ctx_load_cryptoapi(struct tls_root_ctx *ctx, const char *cryptoapi_cert)
+{
+  msg(M_FATAL, "Windows CryptoAPI not yet supported for PolarSSL.");
+}
+#endif /* WIN32 */
+
+void
+tls_ctx_load_cert_file (struct tls_root_ctx *ctx, const char *cert_file,
+    const char *cert_file_inline,
+    openvpn_x509_cert_t **x509
+    )
+{
+  ASSERT(NULL != ctx);
+  if (NULL != x509)
+    ASSERT(NULL == *x509);
+
+  if (!strcmp (cert_file, INLINE_FILE_TAG) && cert_file_inline)
+    {
+      if (0 != x509parse_crt(ctx->crt_chain, cert_file_inline,
+	  strlen(cert_file_inline)))
+        msg (M_FATAL, "Cannot load inline certificate file");
+    }
+  else
+    {
+      if (0 != x509parse_crtfile(ctx->crt_chain, cert_file))
+	msg (M_FATAL, "Cannot load certificate file %s", cert_file);
+    }
+  if (x509)
+    {
+      *x509 = ctx->crt_chain;
+    }
+}
+
+void
+tls_ctx_free_cert_file (openvpn_x509_cert_t *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;
+  ASSERT(NULL != ctx);
+
+  if (!strcmp (priv_key_file, INLINE_FILE_TAG) && priv_key_file_inline)
+    {
+      status = x509parse_key(ctx->priv_key,
+	  priv_key_file_inline, strlen(priv_key_file_inline),
+	  NULL, 0);
+      if (POLARSSL_ERR_PEM_PASSWORD_REQUIRED == status)
+	{
+	  char passbuf[512] = {0};
+	  pem_password_callback(passbuf, 512, 0, NULL);
+	  status = x509parse_key(ctx->priv_key,
+	      priv_key_file_inline, strlen(priv_key_file_inline),
+	      passbuf, strlen(passbuf));
+	}
+    }
+  else
+    {
+      status = x509parse_keyfile(ctx->priv_key, priv_key_file, NULL);
+      if (POLARSSL_ERR_PEM_PASSWORD_REQUIRED == status)
+	{
+	  char passbuf[512] = {0};
+	  pem_password_callback(passbuf, 512, 0, NULL);
+	  status = x509parse_keyfile(ctx->priv_key, priv_key_file, passbuf);
+	}
+    }
+  if (0 != status)
+    {
+#ifdef ENABLE_MANAGEMENT
+      if (management && (POLARSSL_ERR_PEM_PASSWORD_MISMATCH == status))
+	  management_auth_failure (management, UP_TYPE_PRIVATE_KEY, NULL);
+#endif
+      msg (M_WARN, "Cannot load private key file %s", priv_key_file);
+      return 1;
+    }
+
+  warn_if_group_others_accessible (priv_key_file);
+
+  /* TODO: Check Private Key */
+#if 0
+  if (!SSL_CTX_check_private_key (ctx))
+    msg (M_SSLERR, "Private key does not match the certificate");
+#endif
+  return 0;
+}
+
+#ifdef MANAGMENT_EXTERNAL_KEY
+
+int
+tls_ctx_use_external_private_key (struct tls_root_ctx *ctx, openvpn_x509_cert_t *cert)
+{
+  msg(M_FATAL, "Use of management external keys not yet supported for PolarSSL.");
+  return false;
+}
+
+#endif
+
+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
+    )
+{
+  if (ca_path)
+      msg(M_FATAL, "ERROR: PolarSSL cannot handle the capath directive");
+
+  if (ca_file && !strcmp (ca_file, INLINE_FILE_TAG) && ca_file_inline)
+    {
+      if (0 != x509parse_crt(ctx->ca_chain, ca_file_inline, strlen(ca_file_inline)))
+	msg (M_FATAL, "Cannot load inline CA certificates");
+    }
+  else
+    {
+      /* Load CA file for verifying peer supplied certificate */
+      if (0 != x509parse_crtfile(ctx->ca_chain, ca_file))
+	msg (M_FATAL, "Cannot load CA certificate file %s", ca_file);
+    }
+}
+
+void
+tls_ctx_load_extra_certs (struct tls_root_ctx *ctx, const char *extra_certs_file,
+    const char *extra_certs_file_inline
+    )
+{
+  ASSERT(NULL != ctx);
+
+  if (!strcmp (extra_certs_file, INLINE_FILE_TAG) && extra_certs_file_inline)
+    {
+      if (0 != x509parse_crt(ctx->crt_chain, extra_certs_file_inline,
+	  strlen(extra_certs_file_inline)))
+        msg (M_FATAL, "Cannot load inline extra-certs file");
+    }
+  else
+    {
+      if (0 != x509parse_crtfile(ctx->crt_chain, extra_certs_file))
+	msg (M_FATAL, "Cannot load extra-certs file: %s", extra_certs_file);
+    }
+}
+
+/* **************************************
+ *
+ * Key-state specific functions
+ *
+ ***************************************/
+
+/*
+ * "Endless buffer"
+ */
+
+static inline void buf_free_entry(buffer_entry *entry)
+{
+  if (NULL != entry)
+    {
+      free(entry->data);
+      free(entry);
+    }
+}
+
+static void buf_free_entries(endless_buffer *buf)
+{
+  while(buf->first_block)
+    {
+      buffer_entry *cur_block = buf->first_block;
+      buf->first_block = cur_block->next_block;
+      buf_free_entry(cur_block);
+    }
+  buf->last_block = NULL;
+}
+
+static int endless_buf_read( void * ctx, unsigned char * out, size_t out_len )
+{
+  endless_buffer *in = (endless_buffer *) ctx;
+  size_t read_len = 0;
+
+  if (in->first_block == NULL)
+    return POLARSSL_ERR_NET_WANT_READ;
+
+  while (in->first_block != NULL && read_len < out_len)
+    {
+      int block_len = in->first_block->length - in->data_start;
+      if (block_len <= out_len - read_len)
+	{
+	  buffer_entry *cur_entry = in->first_block;
+	  memcpy(out + read_len, cur_entry->data + in->data_start,
+	      block_len);
+
+	  read_len += block_len;
+
+	  in->first_block = cur_entry->next_block;
+	  in->data_start = 0;
+
+	  if (in->first_block == NULL)
+	    in->last_block = NULL;
+
+	  buf_free_entry(cur_entry);
+	}
+      else
+	{
+	  memcpy(out + read_len, in->first_block->data + in->data_start,
+	      out_len - read_len);
+	  in->data_start += out_len - read_len;
+	  read_len = out_len;
+	}
+    }
+
+  return read_len;
+}
+
+static int endless_buf_write( void *ctx, const unsigned char *in, size_t len )
+{
+  endless_buffer *out = (endless_buffer *) ctx;
+  buffer_entry *new_block = malloc(sizeof(buffer_entry));
+  if (NULL == new_block)
+    return POLARSSL_ERR_NET_SEND_FAILED;
+
+  new_block->data = malloc(len);
+  if (NULL == new_block->data)
+    {
+      free(new_block);
+      return POLARSSL_ERR_NET_SEND_FAILED;
+    }
+
+  new_block->length = len;
+  new_block->next_block = NULL;
+
+  memcpy(new_block->data, in, len);
+
+  if (NULL == out->first_block)
+    out->first_block = new_block;
+
+  if (NULL != out->last_block)
+    out->last_block->next_block = new_block;
+
+  out->last_block = new_block;
+
+  return len;
+}
+
+static void my_debug( void *ctx, int level, const char *str )
+{
+  if (level == 1)
+    {
+      dmsg (D_HANDSHAKE_VERBOSE, "PolarSSL alert: %s", str);
+    }
+}
+
+/*
+ * Further personalise the RNG using a hash of the public key
+ */
+void tls_ctx_personalise_random(struct tls_root_ctx *ctx)
+{
+  static char old_sha256_hash[32] = {0};
+  char sha256_hash[32] = {0};
+  ctr_drbg_context *cd_ctx = rand_ctx_get();
+
+  if (NULL != ctx->crt_chain)
+    {
+      x509_cert *cert = ctx->crt_chain;
+
+      sha2(cert->tbs.p, cert->tbs.len, sha256_hash, false);
+      if ( 0 != memcmp(old_sha256_hash, sha256_hash, sizeof(sha256_hash)))
+	{
+	  ctr_drbg_update(cd_ctx, sha256_hash, 32);
+	  memcpy(old_sha256_hash, sha256_hash, sizeof(old_sha256_hash));
+	}
+    }
+}
+
+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);
+
+  ALLOC_OBJ_CLEAR(ks_ssl->ctx, ssl_context);
+  if (0 == ssl_init(ks_ssl->ctx))
+    {
+      /* Initialise SSL context */
+      ssl_set_dbg (ks_ssl->ctx, my_debug, NULL);
+      ssl_set_endpoint (ks_ssl->ctx, ssl_ctx->endpoint);
+
+      ssl_set_rng (ks_ssl->ctx, ctr_drbg_random, rand_ctx_get());
+
+      ALLOC_OBJ_CLEAR (ks_ssl->ssn, ssl_session);
+      ssl_set_session (ks_ssl->ctx, 0, 0, ks_ssl->ssn );
+      if (ssl_ctx->allowed_ciphers)
+	ssl_set_ciphersuites (ks_ssl->ctx, ssl_ctx->allowed_ciphers);
+      else
+	ssl_set_ciphersuites (ks_ssl->ctx, default_ciphersuites);
+
+      /* Initialise authentication information */
+      if (is_server)
+	ssl_set_dh_param_ctx (ks_ssl->ctx, ssl_ctx->dhm_ctx );
+#if defined(ENABLE_PKCS11)
+      if (ssl_ctx->priv_key_pkcs11 != NULL)
+	ssl_set_own_cert_pkcs11( ks_ssl->ctx, ssl_ctx->crt_chain,
+	    ssl_ctx->priv_key_pkcs11 );
+      else
+#endif
+	ssl_set_own_cert( ks_ssl->ctx, ssl_ctx->crt_chain, ssl_ctx->priv_key );
+
+      /* Initialise SSL verification */
+      ssl_set_authmode (ks_ssl->ctx, SSL_VERIFY_REQUIRED);
+      ssl_set_verify (ks_ssl->ctx, verify_callback, session);
+      /* TODO: PolarSSL does not currently support sending the CA chain to the client */
+      ssl_set_ca_chain (ks_ssl->ctx, ssl_ctx->ca_chain, NULL, NULL );
+
+      /* Initialise BIOs */
+      ALLOC_OBJ_CLEAR (ks_ssl->ct_in, endless_buffer);
+      ALLOC_OBJ_CLEAR (ks_ssl->ct_out, endless_buffer);
+      ssl_set_bio (ks_ssl->ctx, endless_buf_read, ks_ssl->ct_in,
+	  endless_buf_write, ks_ssl->ct_out);
+
+    }
+}
+
+void
+key_state_ssl_free(struct key_state_ssl *ks_ssl)
+{
+  if (ks_ssl) {
+      if (ks_ssl->ctx)
+	{
+	  ssl_free(ks_ssl->ctx);
+	  free(ks_ssl->ctx);
+	}
+      if (ks_ssl->ssn)
+	free(ks_ssl->ssn);
+      if (ks_ssl->ct_in) {
+	buf_free_entries(ks_ssl->ct_in);
+	free(ks_ssl->ct_in);
+      }
+      if (ks_ssl->ct_out) {
+	buf_free_entries(ks_ssl->ct_out);
+	free(ks_ssl->ct_out);
+      }
+      CLEAR(*ks_ssl);
+  }
+}
+
+int
+key_state_write_plaintext (struct key_state_ssl *ks, struct buffer *buf)
+{
+  int retval = 0;
+  perf_push (PERF_BIO_WRITE_PLAINTEXT);
+
+  ASSERT (NULL != ks);
+  ASSERT (buf);
+  ASSERT (buf->len >= 0);
+
+  if (0 == buf->len)
+    {
+      return 0;
+      perf_pop ();
+    }
+
+  retval = ssl_write(ks->ctx, BPTR(buf), buf->len);
+
+  if (retval < 0)
+    {
+      perf_pop ();
+      if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
+	return 0;
+      msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_plaintext error");
+      return -1;
+    }
+
+  if (retval != buf->len)
+    {
+      msg (D_TLS_ERRORS,
+	  "TLS ERROR: write tls_write_plaintext incomplete %d/%d",
+	  retval, buf->len);
+      perf_pop ();
+      return -1;
+    }
+
+  /* successful write */
+  dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_plaintext %d bytes", retval);
+
+  memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
+  buf->len = 0;
+
+  perf_pop ();
+  return 1;
+}
+
+int
+key_state_write_plaintext_const (struct key_state_ssl *ks, const uint8_t *data, int len)
+{
+  int retval = 0;
+  perf_push (PERF_BIO_WRITE_PLAINTEXT);
+
+  ASSERT (NULL != ks);
+  ASSERT (len >= 0);
+
+  if (0 == len)
+    {
+      perf_pop ();
+      return 0;
+    }
+
+  ASSERT (data);
+
+  retval = ssl_write(ks->ctx, data, len);
+
+  if (retval < 0)
+    {
+      perf_pop ();
+      if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
+	return 0;
+      msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_plaintext_const error");
+      return -1;
+    }
+
+  if (retval != len)
+    {
+      msg (D_TLS_ERRORS,
+	  "TLS ERROR: write tls_write_plaintext_const incomplete %d/%d",
+	  retval, len);
+      perf_pop ();
+      return -1;
+    }
+
+  /* successful write */
+  dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_plaintext_const %d bytes", retval);
+
+  perf_pop ();
+  return 1;
+}
+
+int
+key_state_read_ciphertext (struct key_state_ssl *ks, struct buffer *buf,
+    int maxlen)
+{
+  int retval = 0;
+  int len = 0;
+
+  perf_push (PERF_BIO_READ_CIPHERTEXT);
+
+  ASSERT (NULL != ks);
+  ASSERT (buf);
+  ASSERT (buf->len >= 0);
+
+  if (buf->len)
+    {
+      perf_pop ();
+      return 0;
+    }
+
+  len = buf_forward_capacity (buf);
+  if (maxlen < len)
+    len = maxlen;
+
+  retval = endless_buf_read(ks->ct_out, BPTR(buf), len);
+
+  /* Error during read, check for retry error */
+  if (retval < 0)
+    {
+      perf_pop ();
+      if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
+	return 0;
+      msg (D_TLS_ERRORS, "TLS_ERROR: read tls_read_plaintext error");
+      buf->len = 0;
+      return -1;
+    }
+  /* Nothing read, try again */
+  if (0 == retval)
+    {
+      buf->len = 0;
+      perf_pop ();
+      return 0;
+    }
+
+  /* successful read */
+  dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_ciphertext %d bytes", retval);
+  buf->len = retval;
+  perf_pop ();
+  return 1;
+}
+
+int
+key_state_write_ciphertext (struct key_state_ssl *ks, struct buffer *buf)
+{
+  int retval = 0;
+  perf_push (PERF_BIO_WRITE_CIPHERTEXT);
+
+  ASSERT (NULL != ks);
+  ASSERT (buf);
+  ASSERT (buf->len >= 0);
+
+  if (0 == buf->len)
+    {
+      perf_pop ();
+      return 0;
+    }
+
+  retval = endless_buf_write(ks->ct_in, BPTR(buf), buf->len);
+
+  if (retval < 0)
+    {
+      perf_pop ();
+
+      if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
+	return 0;
+      msg (D_TLS_ERRORS, "TLS ERROR: write tls_write_ciphertext error");
+      return -1;
+    }
+
+  if (retval != buf->len)
+    {
+      msg (D_TLS_ERRORS,
+	  "TLS ERROR: write tls_write_ciphertext incomplete %d/%d",
+	  retval, buf->len);
+      perf_pop ();
+      return -1;
+    }
+
+  /* successful write */
+  dmsg (D_HANDSHAKE_VERBOSE, "write tls_write_ciphertext %d bytes", retval);
+
+  memset (BPTR (buf), 0, BLEN (buf)); /* erase data just written */
+  buf->len = 0;
+
+  perf_pop ();
+  return 1;
+}
+
+int
+key_state_read_plaintext (struct key_state_ssl *ks, struct buffer *buf,
+    int maxlen)
+{
+  int retval = 0;
+  int len = 0;
+
+  perf_push (PERF_BIO_READ_PLAINTEXT);
+
+  ASSERT (NULL != ks);
+  ASSERT (buf);
+  ASSERT (buf->len >= 0);
+
+  if (buf->len)
+    {
+      perf_pop ();
+      return 0;
+    }
+
+  len = buf_forward_capacity (buf);
+  if (maxlen < len)
+    len = maxlen;
+
+  retval = ssl_read(ks->ctx, BPTR(buf), len);
+
+  /* Error during read, check for retry error */
+  if (retval < 0)
+    {
+      if (POLARSSL_ERR_NET_WANT_WRITE == retval || POLARSSL_ERR_NET_WANT_READ == retval)
+	return 0;
+      msg (D_TLS_ERRORS, "TLS_ERROR: read tls_read_plaintext error");
+      buf->len = 0;
+      perf_pop ();
+      return -1;
+    }
+  /* Nothing read, try again */
+  if (0 == retval)
+    {
+      buf->len = 0;
+      perf_pop ();
+      return 0;
+    }
+
+  /* successful read */
+  dmsg (D_HANDSHAKE_VERBOSE, "read tls_read_plaintext %d bytes", retval);
+  buf->len = retval;
+
+  perf_pop ();
+  return 1;
+}
+
+/* **************************************
+ *
+ * Information functions
+ *
+ * Print information for the end user.
+ *
+ ***************************************/
+void
+print_details (struct key_state_ssl * ks_ssl, const char *prefix)
+{
+  x509_cert *cert;
+  char s1[256];
+  char s2[256];
+
+  s1[0] = s2[0] = 0;
+  openvpn_snprintf (s1, sizeof (s1), "%s %s, cipher %s",
+		    prefix,
+		    ssl_get_version (ks_ssl->ctx),
+		    ssl_get_ciphersuite(ks_ssl->ctx));
+
+  cert = ks_ssl->ctx->peer_cert;
+  if (cert != NULL)
+    {
+      openvpn_snprintf (s2, sizeof (s2), ", " counter_format " bit RSA", (counter_type) cert->rsa.len * 8);
+    }
+
+  msg (D_HANDSHAKE, "%s%s", s1, s2);
+}
+
+void
+show_available_tls_ciphers ()
+{
+  const int *ciphers = ssl_list_ciphersuites();
+
+#ifndef ENABLE_SMALL
+  printf ("Available TLS Ciphers,\n");
+  printf ("listed in order of preference:\n\n");
+#endif
+
+  while (*ciphers != 0)
+    {
+      printf ("%s\n", ssl_get_ciphersuite_name(*ciphers));
+      ciphers++;
+    }
+  printf ("\n");
+}
+
+void
+get_highest_preference_tls_cipher (char *buf, int size)
+{
+  const char *cipher_name;
+  const int *ciphers = ssl_list_ciphersuites();
+  if (*ciphers == 0)
+    msg (M_FATAL, "Cannot retrieve list of supported SSL ciphers.");
+
+  cipher_name = ssl_get_ciphersuite_name(*ciphers);
+  strncpynt (buf, cipher_name, size);
+}
+
+#endif /* defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL) */