New upstream version 2.4~beta1upstream/2.4_beta1

1 files changed, 785 insertions, 0 deletions

diff --git a/src/openvpn/crypto_mbedtls.c b/src/openvpn/crypto_mbedtls.c
new file mode 100644
index 0000000..6ad5924
--- /dev/null
+++ b/src/openvpn/crypto_mbedtls.c
@@ -0,0 +1,785 @@
+/*
+ *  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 Data Channel Cryptography mbed TLS-specific backend interface
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_CRYPTO) && defined(ENABLE_CRYPTO_MBEDTLS)
+
+#include "errlevel.h"
+#include "basic.h"
+#include "buffer.h"
+#include "integer.h"
+#include "crypto_backend.h"
+#include "otime.h"
+#include "misc.h"
+
+#include <mbedtls/des.h>
+#include <mbedtls/error.h>
+#include <mbedtls/md5.h>
+#include <mbedtls/cipher.h>
+#include <mbedtls/havege.h>
+
+#include <mbedtls/entropy.h>
+
+
+/*
+ *
+ * Hardware engine support. Allows loading/unloading of engines.
+ *
+ */
+
+void
+crypto_init_lib_engine (const char *engine_name)
+{
+  msg (M_WARN, "Note: mbed TLS hardware crypto engine functionality is not "
+      "available");
+}
+
+/*
+ *
+ * Functions related to the core crypto library
+ *
+ */
+
+void
+crypto_init_lib (void)
+{
+}
+
+void
+crypto_uninit_lib (void)
+{
+}
+
+void
+crypto_clear_error (void)
+{
+}
+
+bool mbed_log_err(unsigned int flags, int errval, const char *prefix)
+{
+  if (0 != errval)
+    {
+      char errstr[256];
+      mbedtls_strerror(errval, errstr, sizeof(errstr));
+
+      if (NULL == prefix) prefix = "mbed TLS error";
+      msg (flags, "%s: %s", prefix, errstr);
+    }
+
+  return 0 == errval;
+}
+
+bool mbed_log_func_line(unsigned int flags, int errval, const char *func,
+    int line)
+{
+  char prefix[256];
+
+  if (!openvpn_snprintf(prefix, sizeof(prefix), "%s:%d", func, line))
+    return mbed_log_err(flags, errval, func);
+
+  return mbed_log_err(flags, errval, prefix);
+}
+
+
+#ifdef DMALLOC
+void
+crypto_init_dmalloc (void)
+{
+  msg (M_ERR, "Error: dmalloc support is not available for mbed TLS.");
+}
+#endif /* DMALLOC */
+
+const cipher_name_pair cipher_name_translation_table[] = {
+    { "BF-CBC", "BLOWFISH-CBC" },
+    { "BF-CFB", "BLOWFISH-CFB64" },
+    { "CAMELLIA-128-CFB", "CAMELLIA-128-CFB128" },
+    { "CAMELLIA-192-CFB", "CAMELLIA-192-CFB128" },
+    { "CAMELLIA-256-CFB", "CAMELLIA-256-CFB128" }
+};
+const size_t cipher_name_translation_table_count =
+    sizeof (cipher_name_translation_table) / sizeof (*cipher_name_translation_table);
+
+static void print_cipher(const cipher_kt_t *info)
+{
+  if (info && (cipher_kt_mode_cbc(info)
+#ifdef HAVE_AEAD_CIPHER_MODES
+      || cipher_kt_mode_aead(info)
+#endif
+  ))
+    {
+      const char *ssl_only = cipher_kt_mode_cbc(info) ?
+	  "" : ", TLS client/server mode only";
+      const char *var_key_size = info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN ?
+	  " by default" : "";
+
+      printf ("%s  (%d bit key%s, %d bit block%s)\n",
+	  cipher_kt_name(info), cipher_kt_key_size(info) * 8, var_key_size,
+	  cipher_kt_block_size(info) * 8, ssl_only);
+    }
+}
+
+void
+show_available_ciphers ()
+{
+  const int *ciphers = mbedtls_cipher_list();
+
+#ifndef ENABLE_SMALL
+  printf ("The following ciphers and cipher modes are available for use\n"
+	  "with " PACKAGE_NAME ".  Each cipher shown below may be used as a\n"
+	  "parameter to the --cipher option.  Using a CBC or GCM mode is\n"
+	  "recommended.  In static key mode only CBC mode is allowed.\n\n");
+#endif
+
+  while (*ciphers != 0)
+    {
+      const cipher_kt_t *info = mbedtls_cipher_info_from_type(*ciphers);
+      if (info && cipher_kt_block_size(info) >= 128/8)
+	{
+	  print_cipher(info);
+	}
+      ciphers++;
+    }
+
+  printf ("\nThe following ciphers have a block size of less than 128 bits, \n"
+	  "and are therefore deprecated.  Do not use unless you have to.\n\n");
+  ciphers = mbedtls_cipher_list();
+  while (*ciphers != 0)
+    {
+      const cipher_kt_t *info = mbedtls_cipher_info_from_type(*ciphers);
+      if (info && cipher_kt_block_size(info) < 128/8)
+	{
+	  print_cipher(info);
+	}
+      ciphers++;
+    }
+  printf ("\n");
+}
+
+void
+show_available_digests ()
+{
+  const int *digests = mbedtls_md_list();
+
+#ifndef ENABLE_SMALL
+  printf ("The following message digests are available for use with\n"
+	  PACKAGE_NAME ".  A message digest is used in conjunction with\n"
+	  "the HMAC function, to authenticate received packets.\n"
+	  "You can specify a message digest as parameter to\n"
+	  "the --auth option.\n\n");
+#endif
+
+  while (*digests != 0)
+    {
+      const mbedtls_md_info_t *info = mbedtls_md_info_from_type(*digests);
+
+      if (info)
+	printf ("%s %d bit default key\n", mbedtls_md_get_name(info),
+	    mbedtls_md_get_size(info) * 8);
+      digests++;
+    }
+  printf ("\n");
+}
+
+void
+show_available_engines ()
+{
+  printf ("Sorry, mbed TLS hardware crypto engine functionality is not "
+      "available\n");
+}
+
+/*
+ *
+ * Random number functions, used in cases where we want
+ * reasonably strong cryptographic random number generation
+ * without depleting our entropy pool.  Used for random
+ * IV values and a number of other miscellaneous tasks.
+ *
+ */
+
+/*
+ * Initialise the given ctr_drbg context, using a personalisation string and an
+ * entropy gathering function.
+ */
+mbedtls_ctr_drbg_context * rand_ctx_get()
+{
+  static mbedtls_entropy_context ec = {0};
+  static mbedtls_ctr_drbg_context cd_ctx = {0};
+  static bool rand_initialised = false;
+
+  if (!rand_initialised)
+    {
+      struct gc_arena gc = gc_new();
+      struct buffer pers_string = alloc_buf_gc(100, &gc);
+
+      /*
+       * Personalisation string, should be as unique as possible (see NIST
+       * 800-90 section 8.7.1). We have very little information at this stage.
+       * Include Program Name, memory address of the context and PID.
+       */
+      buf_printf(&pers_string, "OpenVPN %0u %p %s", platform_getpid(), &cd_ctx, time_string(0, 0, 0, &gc));
+
+      /* Initialise mbed TLS RNG, and built-in entropy sources */
+      mbedtls_entropy_init(&ec);
+
+      mbedtls_ctr_drbg_init(&cd_ctx);
+      if (!mbed_ok(mbedtls_ctr_drbg_seed(&cd_ctx, mbedtls_entropy_func, &ec,
+		    BPTR(&pers_string), BLEN(&pers_string))))
+        msg (M_FATAL, "Failed to initialize random generator");
+
+      gc_free(&gc);
+      rand_initialised = true;
+  }
+
+  return &cd_ctx;
+}
+
+#ifdef ENABLE_PREDICTION_RESISTANCE
+void rand_ctx_enable_prediction_resistance()
+{
+  mbedtls_ctr_drbg_context *cd_ctx = rand_ctx_get();
+
+  mbedtls_ctr_drbg_set_prediction_resistance(cd_ctx, 1);
+}
+#endif /* ENABLE_PREDICTION_RESISTANCE */
+
+int
+rand_bytes (uint8_t *output, int len)
+{
+  mbedtls_ctr_drbg_context *rng_ctx = rand_ctx_get();
+
+  while (len > 0)
+    {
+      const size_t blen = min_int (len, MBEDTLS_CTR_DRBG_MAX_REQUEST);
+      if (0 != mbedtls_ctr_drbg_random(rng_ctx, output, blen))
+	return 0;
+
+      output += blen;
+      len -= blen;
+    }
+
+  return 1;
+}
+
+/*
+ *
+ * Key functions, allow manipulation of keys.
+ *
+ */
+
+
+int
+key_des_num_cblocks (const mbedtls_cipher_info_t *kt)
+{
+  int ret = 0;
+  if (kt->type == MBEDTLS_CIPHER_DES_CBC)
+    ret = 1;
+  if (kt->type == MBEDTLS_CIPHER_DES_EDE_CBC)
+    ret = 2;
+  if (kt->type == MBEDTLS_CIPHER_DES_EDE3_CBC)
+    ret = 3;
+
+  dmsg (D_CRYPTO_DEBUG, "CRYPTO INFO: n_DES_cblocks=%d", ret);
+  return ret;
+}
+
+bool
+key_des_check (uint8_t *key, int key_len, int ndc)
+{
+  int i;
+  struct buffer b;
+
+  buf_set_read (&b, key, key_len);
+
+  for (i = 0; i < ndc; ++i)
+    {
+      unsigned char *key = buf_read_alloc(&b, MBEDTLS_DES_KEY_SIZE);
+      if (!key)
+	{
+	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: insufficient key material");
+	  goto err;
+	}
+      if (0 != mbedtls_des_key_check_weak(key))
+	{
+	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: weak key detected");
+	  goto err;
+	}
+      if (0 != mbedtls_des_key_check_key_parity(key))
+	{
+	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: bad parity detected");
+	  goto err;
+	}
+    }
+  return true;
+
+ err:
+  return false;
+}
+
+void
+key_des_fixup (uint8_t *key, int key_len, int ndc)
+{
+  int i;
+  struct buffer b;
+
+  buf_set_read (&b, key, key_len);
+  for (i = 0; i < ndc; ++i)
+    {
+      unsigned char *key = buf_read_alloc(&b, MBEDTLS_DES_KEY_SIZE);
+      if (!key)
+	{
+	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: fixup_key_DES: insufficient key material");
+	  return;
+	}
+      mbedtls_des_key_set_parity(key);
+    }
+}
+
+/*
+ *
+ * Generic cipher key type functions
+ *
+ */
+
+
+const mbedtls_cipher_info_t *
+cipher_kt_get (const char *ciphername)
+{
+  const mbedtls_cipher_info_t *cipher = NULL;
+
+  ASSERT (ciphername);
+
+  cipher = mbedtls_cipher_info_from_string(ciphername);
+
+  if (NULL == cipher)
+    {
+      msg (D_LOW, "Cipher algorithm '%s' not found", ciphername);
+      return NULL;
+    }
+
+  if (cipher->key_bitlen/8 > MAX_CIPHER_KEY_LENGTH)
+    {
+      msg (D_LOW, "Cipher algorithm '%s' uses a default key size (%d bytes) "
+	  "which is larger than " PACKAGE_NAME "'s current maximum key size "
+	  "(%d bytes)", ciphername, cipher->key_bitlen/8, MAX_CIPHER_KEY_LENGTH);
+      return NULL;
+    }
+
+  return cipher;
+}
+
+const char *
+cipher_kt_name (const mbedtls_cipher_info_t *cipher_kt)
+{
+  if (NULL == cipher_kt)
+    return "[null-cipher]";
+
+  return translate_cipher_name_to_openvpn(cipher_kt->name);
+}
+
+int
+cipher_kt_key_size (const mbedtls_cipher_info_t *cipher_kt)
+{
+  if (NULL == cipher_kt)
+    return 0;
+
+  return cipher_kt->key_bitlen/8;
+}
+
+int
+cipher_kt_iv_size (const mbedtls_cipher_info_t *cipher_kt)
+{
+  if (NULL == cipher_kt)
+    return 0;
+  return cipher_kt->iv_size;
+}
+
+int
+cipher_kt_block_size (const mbedtls_cipher_info_t *cipher_kt)
+{
+  if (NULL == cipher_kt)
+    return 0;
+  return cipher_kt->block_size;
+}
+
+int
+cipher_kt_tag_size (const mbedtls_cipher_info_t *cipher_kt)
+{
+#ifdef HAVE_AEAD_CIPHER_MODES
+  if (cipher_kt && cipher_kt_mode_aead(cipher_kt))
+    return OPENVPN_AEAD_TAG_LENGTH;
+#endif
+  return 0;
+}
+
+int
+cipher_kt_mode (const mbedtls_cipher_info_t *cipher_kt)
+{
+  ASSERT(NULL != cipher_kt);
+  return cipher_kt->mode;
+}
+
+bool
+cipher_kt_mode_cbc(const cipher_kt_t *cipher)
+{
+  return cipher && cipher_kt_mode(cipher) == OPENVPN_MODE_CBC;
+}
+
+bool
+cipher_kt_mode_ofb_cfb(const cipher_kt_t *cipher)
+{
+  return cipher && (cipher_kt_mode(cipher) == OPENVPN_MODE_OFB ||
+      cipher_kt_mode(cipher) == OPENVPN_MODE_CFB);
+}
+
+bool
+cipher_kt_mode_aead(const cipher_kt_t *cipher)
+{
+  return cipher && cipher_kt_mode(cipher) == OPENVPN_MODE_GCM;
+}
+
+
+/*
+ *
+ * Generic cipher context functions
+ *
+ */
+
+
+void
+cipher_ctx_init (mbedtls_cipher_context_t *ctx, uint8_t *key, int key_len,
+    const mbedtls_cipher_info_t *kt, const mbedtls_operation_t operation)
+{
+  ASSERT(NULL != kt && NULL != ctx);
+
+  CLEAR (*ctx);
+
+  if (!mbed_ok(mbedtls_cipher_setup(ctx, kt)))
+    msg (M_FATAL, "mbed TLS cipher context init #1");
+
+  if (!mbed_ok(mbedtls_cipher_setkey(ctx, key, key_len*8, operation)))
+    msg (M_FATAL, "mbed TLS cipher set key");
+
+  /* make sure we used a big enough key */
+  ASSERT (ctx->key_bitlen <= key_len*8);
+}
+
+void cipher_ctx_cleanup (mbedtls_cipher_context_t *ctx)
+{
+  mbedtls_cipher_free(ctx);
+}
+
+int cipher_ctx_iv_length (const mbedtls_cipher_context_t *ctx)
+{
+  return mbedtls_cipher_get_iv_size(ctx);
+}
+
+int cipher_ctx_get_tag (cipher_ctx_t *ctx, uint8_t* tag, int tag_len)
+{
+#ifdef HAVE_AEAD_CIPHER_MODES
+  if (tag_len > SIZE_MAX)
+    return 0;
+
+  if (!mbed_ok (mbedtls_cipher_write_tag (ctx, (unsigned char *) tag, tag_len)))
+    return 0;
+
+  return 1;
+#else
+  ASSERT(0);
+#endif /* HAVE_AEAD_CIPHER_MODES */
+}
+
+int cipher_ctx_block_size(const mbedtls_cipher_context_t *ctx)
+{
+  return mbedtls_cipher_get_block_size(ctx);
+}
+
+int cipher_ctx_mode (const mbedtls_cipher_context_t *ctx)
+{
+  ASSERT(NULL != ctx);
+
+  return cipher_kt_mode(ctx->cipher_info);
+}
+
+const cipher_kt_t *
+cipher_ctx_get_cipher_kt (const cipher_ctx_t *ctx)
+{
+  return ctx ? ctx->cipher_info : NULL;
+}
+
+int cipher_ctx_reset (mbedtls_cipher_context_t *ctx, uint8_t *iv_buf)
+{
+  if (!mbed_ok(mbedtls_cipher_reset(ctx)))
+    return 0;
+
+  if (!mbed_ok(mbedtls_cipher_set_iv(ctx, iv_buf, ctx->cipher_info->iv_size)))
+    return 0;
+
+  return 1;
+}
+
+int cipher_ctx_update_ad (cipher_ctx_t *ctx, const uint8_t *src, int src_len)
+{
+#ifdef HAVE_AEAD_CIPHER_MODES
+  if (src_len > SIZE_MAX)
+    return 0;
+
+  if (!mbed_ok (mbedtls_cipher_update_ad (ctx, src, src_len)))
+    return 0;
+
+  return 1;
+#else
+  ASSERT(0);
+#endif /* HAVE_AEAD_CIPHER_MODES */
+}
+
+int cipher_ctx_update (mbedtls_cipher_context_t *ctx, uint8_t *dst,
+    int *dst_len, uint8_t *src, int src_len)
+{
+  size_t s_dst_len = *dst_len;
+
+  if (!mbed_ok(mbedtls_cipher_update(ctx, src, (size_t) src_len, dst,
+      &s_dst_len)))
+    return 0;
+
+  *dst_len = s_dst_len;
+
+  return 1;
+}
+
+int cipher_ctx_final (mbedtls_cipher_context_t *ctx, uint8_t *dst, int *dst_len)
+{
+  size_t s_dst_len = *dst_len;
+
+  if (!mbed_ok(mbedtls_cipher_finish(ctx, dst, &s_dst_len)))
+    return 0;
+
+  *dst_len = s_dst_len;
+
+  return 1;
+}
+
+int cipher_ctx_final_check_tag (mbedtls_cipher_context_t *ctx, uint8_t *dst,
+    int *dst_len, uint8_t *tag, size_t tag_len)
+{
+#ifdef HAVE_AEAD_CIPHER_MODES
+  size_t olen = 0;
+
+  if (MBEDTLS_DECRYPT != ctx->operation)
+    return 0;
+
+  if (tag_len > SIZE_MAX)
+    return 0;
+
+  if (!mbed_ok (mbedtls_cipher_finish (ctx, dst, &olen)))
+    {
+      msg (D_CRYPT_ERRORS, "%s: cipher_ctx_final() failed", __func__);
+      return 0;
+    }
+
+  if (olen > INT_MAX)
+    return 0;
+  *dst_len = olen;
+
+  if (!mbed_ok (mbedtls_cipher_check_tag (ctx, (const unsigned char *) tag,
+      tag_len)))
+    return 0;
+
+  return 1;
+#else
+  ASSERT(0);
+#endif /* HAVE_AEAD_CIPHER_MODES */
+}
+
+void
+cipher_des_encrypt_ecb (const unsigned char key[DES_KEY_LENGTH],
+    unsigned char *src,
+    unsigned char *dst)
+{
+  mbedtls_des_context ctx;
+
+  ASSERT (mbed_ok(mbedtls_des_setkey_enc(&ctx, key)));
+  ASSERT (mbed_ok(mbedtls_des_crypt_ecb(&ctx, src, dst)));
+}
+
+
+
+/*
+ *
+ * Generic message digest information functions
+ *
+ */
+
+
+const mbedtls_md_info_t *
+md_kt_get (const char *digest)
+{
+  const mbedtls_md_info_t *md = NULL;
+  ASSERT (digest);
+
+  md = mbedtls_md_info_from_string(digest);
+  if (!md)
+    msg (M_FATAL, "Message hash algorithm '%s' not found", digest);
+  if (mbedtls_md_get_size(md) > MAX_HMAC_KEY_LENGTH)
+    msg (M_FATAL, "Message hash algorithm '%s' uses a default hash size (%d bytes) which is larger than " PACKAGE_NAME "'s current maximum hash size (%d bytes)",
+	 digest,
+	 mbedtls_md_get_size(md),
+	 MAX_HMAC_KEY_LENGTH);
+  return md;
+}
+
+const char *
+md_kt_name (const mbedtls_md_info_t *kt)
+{
+  if (NULL == kt)
+    return "[null-digest]";
+  return mbedtls_md_get_name (kt);
+}
+
+int
+md_kt_size (const mbedtls_md_info_t *kt)
+{
+  if (NULL == kt)
+    return 0;
+  return mbedtls_md_get_size(kt);
+}
+
+/*
+ *
+ * Generic message digest functions
+ *
+ */
+
+int
+md_full (const md_kt_t *kt, const uint8_t *src, int src_len, uint8_t *dst)
+{
+  return 0 == mbedtls_md(kt, src, src_len, dst);
+}
+
+
+void
+md_ctx_init (mbedtls_md_context_t *ctx, const mbedtls_md_info_t *kt)
+{
+  ASSERT(NULL != ctx && NULL != kt);
+
+  mbedtls_md_init(ctx);
+  ASSERT(0 == mbedtls_md_setup(ctx, kt, 0));
+  ASSERT(0 == mbedtls_md_starts(ctx));
+}
+
+void
+md_ctx_cleanup(mbedtls_md_context_t *ctx)
+{
+}
+
+int
+md_ctx_size (const mbedtls_md_context_t *ctx)
+{
+  if (NULL == ctx)
+    return 0;
+  return mbedtls_md_get_size(ctx->md_info);
+}
+
+void
+md_ctx_update (mbedtls_md_context_t *ctx, const uint8_t *src, int src_len)
+{
+  ASSERT(0 == mbedtls_md_update(ctx, src, src_len));
+}
+
+void
+md_ctx_final (mbedtls_md_context_t *ctx, uint8_t *dst)
+{
+  ASSERT(0 == mbedtls_md_finish(ctx, dst));
+  mbedtls_md_free(ctx);
+}
+
+
+/*
+ *
+ * Generic HMAC functions
+ *
+ */
+
+
+/*
+ * TODO: re-enable dmsg for crypto debug
+ */
+void
+hmac_ctx_init (mbedtls_md_context_t *ctx, const uint8_t *key, int key_len,
+    const mbedtls_md_info_t *kt)
+{
+  ASSERT(NULL != kt && NULL != ctx);
+
+  mbedtls_md_init(ctx);
+  ASSERT(0 == mbedtls_md_setup(ctx, kt, 1));
+  ASSERT(0 == mbedtls_md_hmac_starts(ctx, key, key_len));
+
+  /* make sure we used a big enough key */
+  ASSERT (mbedtls_md_get_size(kt) <= key_len);
+}
+
+void
+hmac_ctx_cleanup(mbedtls_md_context_t *ctx)
+{
+  mbedtls_md_free(ctx);
+}
+
+int
+hmac_ctx_size (const mbedtls_md_context_t *ctx)
+{
+  if (NULL == ctx)
+    return 0;
+  return mbedtls_md_get_size(ctx->md_info);
+}
+
+void
+hmac_ctx_reset (mbedtls_md_context_t *ctx)
+{
+  ASSERT(0 == mbedtls_md_hmac_reset(ctx));
+}
+
+void
+hmac_ctx_update (mbedtls_md_context_t *ctx, const uint8_t *src, int src_len)
+{
+  ASSERT(0 == mbedtls_md_hmac_update(ctx, src, src_len));
+}
+
+void
+hmac_ctx_final (mbedtls_md_context_t *ctx, uint8_t *dst)
+{
+  ASSERT(0 == mbedtls_md_hmac_finish(ctx, dst));
+}
+
+#endif /* ENABLE_CRYPTO && ENABLE_CRYPTO_MBEDTLS */