Imported Upstream version 2.3_rc1

1 files changed, 0 insertions, 1841 deletions

diff --git a/crypto.c b/crypto.c
deleted file mode 100644
index 5cfc34a..0000000
--- a/crypto.c
+++ /dev/null
@@ -1,1841 +0,0 @@
-/*
- *  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>
- *
- *  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
- */
-
-#include "syshead.h"
-
-#ifdef USE_CRYPTO
-
-#include "crypto.h"
-#include "error.h"
-#include "misc.h"
-
-#include "memdbg.h"
-
-/*
- * Check for key size creepage.
- */
-
-#if MAX_CIPHER_KEY_LENGTH < EVP_MAX_KEY_LENGTH
-#warning Some OpenSSL EVP ciphers now support key lengths greater than MAX_CIPHER_KEY_LENGTH -- consider increasing MAX_CIPHER_KEY_LENGTH
-#endif
-
-#if MAX_HMAC_KEY_LENGTH < EVP_MAX_MD_SIZE
-#warning Some OpenSSL HMAC message digests now support key lengths greater than MAX_HMAC_KEY_LENGTH -- consider increasing MAX_HMAC_KEY_LENGTH
-#endif
-
-/*
- * Encryption and Compression Routines.
- *
- * On entry, buf contains the input data and length.
- * On exit, it should be set to the output data and length.
- *
- * If buf->len is <= 0 we should return
- * If buf->len is set to 0 on exit it tells the caller to ignore the packet.
- *
- * work is a workspace buffer we are given of size BUF_SIZE.
- * work may be used to return output data, or the input buffer
- * may be modified and returned as output.  If output data is
- * returned in work, the data should start after FRAME_HEADROOM bytes
- * of padding to leave room for downstream routines to prepend.
- *
- * Up to a total of FRAME_HEADROOM bytes may be prepended to the input buf
- * by all routines (encryption, decryption, compression, and decompression).
- *
- * Note that the buf_prepend return will assert if we try to
- * make a header bigger than FRAME_HEADROOM.  This should not
- * happen unless the frame parameters are wrong.
- */
-
-#define CRYPT_ERROR(format) \
-  do { msg (D_CRYPT_ERRORS, "%s: " format, error_prefix); goto error_exit; } while (false)
-
-void
-openvpn_encrypt (struct buffer *buf, struct buffer work,
-		 const struct crypto_options *opt,
-		 const struct frame* frame)
-{
-  struct gc_arena gc;
-  gc_init (&gc);
-
-  if (buf->len > 0 && opt->key_ctx_bi)
-    {
-      struct key_ctx *ctx = &opt->key_ctx_bi->encrypt;
-
-      /* Do Encrypt from buf -> work */
-      if (ctx->cipher)
-	{
-	  uint8_t iv_buf[EVP_MAX_IV_LENGTH];
-	  const int iv_size = EVP_CIPHER_CTX_iv_length (ctx->cipher);
-	  const unsigned int mode = EVP_CIPHER_CTX_mode (ctx->cipher);  
-	  int outlen;
-
-	  if (mode == EVP_CIPH_CBC_MODE)
-	    {
-	      CLEAR (iv_buf);
-
-	      /* generate pseudo-random IV */
-	      if (opt->flags & CO_USE_IV)
-		prng_bytes (iv_buf, iv_size);
-
-	      /* Put packet ID in plaintext buffer or IV, depending on cipher mode */
-	      if (opt->packet_id)
-		{
-		  struct packet_id_net pin;
-		  packet_id_alloc_outgoing (&opt->packet_id->send, &pin, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM));
-		  ASSERT (packet_id_write (&pin, buf, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM), true));
-		}
-	    }
-	  else if (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE)
-	    {
-	      struct packet_id_net pin;
-	      struct buffer b;
-
-	      ASSERT (opt->flags & CO_USE_IV);    /* IV and packet-ID required */
-	      ASSERT (opt->packet_id); /*  for this mode. */
-
-	      packet_id_alloc_outgoing (&opt->packet_id->send, &pin, true);
-	      memset (iv_buf, 0, iv_size);
-	      buf_set_write (&b, iv_buf, iv_size);
-	      ASSERT (packet_id_write (&pin, &b, true, false));
-	    }
-	  else /* We only support CBC, CFB, or OFB modes right now */
-	    {
-	      ASSERT (0);
-	    }
-
-	  /* initialize work buffer with FRAME_HEADROOM bytes of prepend capacity */
-	  ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
-
-	  /* set the IV pseudo-randomly */
-	  if (opt->flags & CO_USE_IV)
-	    dmsg (D_PACKET_CONTENT, "ENCRYPT IV: %s", format_hex (iv_buf, iv_size, 0, &gc));
-
-	  dmsg (D_PACKET_CONTENT, "ENCRYPT FROM: %s",
-	       format_hex (BPTR (buf), BLEN (buf), 80, &gc));
-
-	  /* cipher_ctx was already initialized with key & keylen */
-	  ASSERT (EVP_CipherInit_ov (ctx->cipher, NULL, NULL, iv_buf, DO_ENCRYPT));
-
-	  /* Buffer overflow check */
-	  if (!buf_safe (&work, buf->len + EVP_CIPHER_CTX_block_size (ctx->cipher)))
-	    {
-	      msg (D_CRYPT_ERRORS, "ENCRYPT: buffer size error, bc=%d bo=%d bl=%d wc=%d wo=%d wl=%d cbs=%d",
-		   buf->capacity,
-		   buf->offset,
-		   buf->len,
-		   work.capacity,
-		   work.offset,
-		   work.len,
-		   EVP_CIPHER_CTX_block_size (ctx->cipher));
-	      goto err;
-	    }
-
-	  /* Encrypt packet ID, payload */
-	  ASSERT (EVP_CipherUpdate_ov (ctx->cipher, BPTR (&work), &outlen, BPTR (buf), BLEN (buf)));
-	  work.len += outlen;
-
-	  /* Flush the encryption buffer */
-	  ASSERT (EVP_CipherFinal (ctx->cipher, BPTR (&work) + outlen, &outlen));
-	  work.len += outlen;
-	  ASSERT (outlen == iv_size);
-
-	  /* prepend the IV to the ciphertext */
-	  if (opt->flags & CO_USE_IV)
-	    {
-	      uint8_t *output = buf_prepend (&work, iv_size);
-	      ASSERT (output);
-	      memcpy (output, iv_buf, iv_size);
-	    }
-
-	  dmsg (D_PACKET_CONTENT, "ENCRYPT TO: %s",
-	       format_hex (BPTR (&work), BLEN (&work), 80, &gc));
-	}
-      else				/* No Encryption */
-	{
-	  if (opt->packet_id)
-	    {
-	      struct packet_id_net pin;
-	      packet_id_alloc_outgoing (&opt->packet_id->send, &pin, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM));
-	      ASSERT (packet_id_write (&pin, buf, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM), true));
-	    }
-	  work = *buf;
-	}
-
-      /* HMAC the ciphertext (or plaintext if !cipher) */
-      if (ctx->hmac)
-	{
-	  int hmac_len;
-	  uint8_t *output;
-
-	  HMAC_Init_ex (ctx->hmac, NULL, 0, NULL, NULL);
-	  HMAC_Update (ctx->hmac, BPTR (&work), BLEN (&work));
-	  output = buf_prepend (&work, HMAC_size (ctx->hmac));
-	  ASSERT (output);
-	  HMAC_Final (ctx->hmac, output, (unsigned int *)&hmac_len);
-	  ASSERT (hmac_len == HMAC_size (ctx->hmac));
-	}
-
-      *buf = work;
-    }
-
-  gc_free (&gc);
-  return;
-
- err:
-  ERR_clear_error ();
-  buf->len = 0;
-  gc_free (&gc);
-  return;
-}
-
-/*
- * If (opt->flags & CO_USE_IV) is not NULL, we will read an IV from the packet.
- *
- * Set buf->len to 0 and return false on decrypt error.
- *
- * On success, buf is set to point to plaintext, true
- * is returned.
- */
-bool
-openvpn_decrypt (struct buffer *buf, struct buffer work,
-		 const struct crypto_options *opt,
-		 const struct frame* frame)
-{
-  static const char error_prefix[] = "Authenticate/Decrypt packet error";
-  struct gc_arena gc;
-  gc_init (&gc);
-
-  if (buf->len > 0 && opt->key_ctx_bi)
-    {
-      struct key_ctx *ctx = &opt->key_ctx_bi->decrypt;
-      struct packet_id_net pin;
-      bool have_pin = false;
-
-      /* Verify the HMAC */
-      if (ctx->hmac)
-	{
-	  int hmac_len;
-	  uint8_t local_hmac[MAX_HMAC_KEY_LENGTH]; /* HMAC of ciphertext computed locally */
-	  int in_hmac_len;
-
-	  HMAC_Init_ex (ctx->hmac, NULL, 0, NULL, NULL);
-
-	  /* Assume the length of the input HMAC */
-	  hmac_len = HMAC_size (ctx->hmac);
-
-	  /* Authentication fails if insufficient data in packet for HMAC */
-	  if (buf->len < hmac_len)
-	    CRYPT_ERROR ("missing authentication info");
-
-	  HMAC_Update (ctx->hmac, BPTR (buf) + hmac_len,
-		       BLEN (buf) - hmac_len);
-	  HMAC_Final (ctx->hmac, local_hmac, (unsigned int *)&in_hmac_len);
-	  ASSERT (hmac_len == in_hmac_len);
-
-	  /* Compare locally computed HMAC with packet HMAC */
-	  if (memcmp (local_hmac, BPTR (buf), hmac_len))
-	    CRYPT_ERROR ("packet HMAC authentication failed");
-
-	  ASSERT (buf_advance (buf, hmac_len));
-	}
-
-      /* Decrypt packet ID + payload */
-
-      if (ctx->cipher)
-	{
-	  const unsigned int mode = EVP_CIPHER_CTX_mode (ctx->cipher);
-	  const int iv_size = EVP_CIPHER_CTX_iv_length (ctx->cipher);
-	  uint8_t iv_buf[EVP_MAX_IV_LENGTH];
-	  int outlen;
-
-	  /* initialize work buffer with FRAME_HEADROOM bytes of prepend capacity */
-	  ASSERT (buf_init (&work, FRAME_HEADROOM_ADJ (frame, FRAME_HEADROOM_MARKER_DECRYPT)));
-
-	  /* use IV if user requested it */
-	  CLEAR (iv_buf);
-	  if (opt->flags & CO_USE_IV)
-	    {
-	      if (buf->len < iv_size)
-		CRYPT_ERROR ("missing IV info");
-	      memcpy (iv_buf, BPTR (buf), iv_size);
-	      ASSERT (buf_advance (buf, iv_size));
-	    }
-
-	  /* show the IV's initial state */
-	  if (opt->flags & CO_USE_IV)
-	    dmsg (D_PACKET_CONTENT, "DECRYPT IV: %s", format_hex (iv_buf, iv_size, 0, &gc));
-
-	  if (buf->len < 1)
-	    CRYPT_ERROR ("missing payload");
-
-	  /* ctx->cipher was already initialized with key & keylen */
-	  if (!EVP_CipherInit_ov (ctx->cipher, NULL, NULL, iv_buf, DO_DECRYPT))
-	    CRYPT_ERROR ("cipher init failed");
-
-	  /* Buffer overflow check (should never happen) */
-	  if (!buf_safe (&work, buf->len))
-	    CRYPT_ERROR ("buffer overflow");
-
-	  /* Decrypt packet ID, payload */
-	  if (!EVP_CipherUpdate_ov (ctx->cipher, BPTR (&work), &outlen, BPTR (buf), BLEN (buf)))
-	    CRYPT_ERROR ("cipher update failed");
-	  work.len += outlen;
-
-	  /* Flush the decryption buffer */
-	  if (!EVP_CipherFinal (ctx->cipher, BPTR (&work) + outlen, &outlen))
-	    CRYPT_ERROR ("cipher final failed");
-	  work.len += outlen;
-
-	  dmsg (D_PACKET_CONTENT, "DECRYPT TO: %s",
-	       format_hex (BPTR (&work), BLEN (&work), 80, &gc));
-
-	  /* Get packet ID from plaintext buffer or IV, depending on cipher mode */
-	  {
-	    if (mode == EVP_CIPH_CBC_MODE)
-	      {
-		if (opt->packet_id)
-		  {
-		    if (!packet_id_read (&pin, &work, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM)))
-		      CRYPT_ERROR ("error reading CBC packet-id");
-		    have_pin = true;
-		  }
-	      }
-	    else if (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE)
-	      {
-		struct buffer b;
-
-		ASSERT (opt->flags & CO_USE_IV);    /* IV and packet-ID required */
-		ASSERT (opt->packet_id); /*  for this mode. */
-
-		buf_set_read (&b, iv_buf, iv_size);
-		if (!packet_id_read (&pin, &b, true))
-		  CRYPT_ERROR ("error reading CFB/OFB packet-id");
-		have_pin = true;
-	      }
-	    else /* We only support CBC, CFB, or OFB modes right now */
-	      {
-		ASSERT (0);
-	      }
-	  }
-	}
-      else
-	{
-	  work = *buf;
-	  if (opt->packet_id)
-	    {
-	      if (!packet_id_read (&pin, &work, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM)))
-		CRYPT_ERROR ("error reading packet-id");
-	      have_pin = !BOOL_CAST (opt->flags & CO_IGNORE_PACKET_ID);
-	    }
-	}
-      
-      if (have_pin)
-	{
-	  packet_id_reap_test (&opt->packet_id->rec);
-	  if (packet_id_test (&opt->packet_id->rec, &pin))
-	    {
-	      packet_id_add (&opt->packet_id->rec, &pin);
-	      if (opt->pid_persist && (opt->flags & CO_PACKET_ID_LONG_FORM))
-		packet_id_persist_save_obj (opt->pid_persist, opt->packet_id);
-	    }
-	  else
-	    {
-	      if (!(opt->flags & CO_MUTE_REPLAY_WARNINGS))
-	      msg (D_REPLAY_ERRORS, "%s: bad packet ID (may be a replay): %s -- see the man page entry for --no-replay and --replay-window for more info or silence this warning with --mute-replay-warnings",
-		   error_prefix, packet_id_net_print (&pin, true, &gc));
-	      goto error_exit;
-	    }
-	}
-      *buf = work;
-    }
-
-  gc_free (&gc);
-  return true;
-
- error_exit:
-  ERR_clear_error ();
-  buf->len = 0;
-  gc_free (&gc);
-  return false;
-}
-
-/*
- * How many bytes will we add to frame buffer for a given
- * set of crypto options?
- */
-void
-crypto_adjust_frame_parameters(struct frame *frame,
-			       const struct key_type* kt,
-			       bool cipher_defined,
-			       bool use_iv,
-			       bool packet_id,
-			       bool packet_id_long_form)
-{
-  frame_add_to_extra_frame (frame,
-			    (packet_id ? packet_id_size (packet_id_long_form) : 0) +
-			    ((cipher_defined && use_iv) ? EVP_CIPHER_iv_length (kt->cipher) : 0) +
-			    (cipher_defined ? EVP_CIPHER_block_size (kt->cipher) : 0) + /* worst case padding expansion */
-			    kt->hmac_length);
-}
-
-static const EVP_CIPHER *
-get_cipher (const char *ciphername)
-{
-  const EVP_CIPHER *cipher = NULL;
-  ASSERT (ciphername);
-  cipher = EVP_get_cipherbyname (ciphername);
-  if ( !(cipher && cipher_ok (OBJ_nid2sn (EVP_CIPHER_nid (cipher)))))
-    msg (M_SSLERR, "Cipher algorithm '%s' not found", ciphername);
-  if (EVP_CIPHER_key_length (cipher) > MAX_CIPHER_KEY_LENGTH)
-    msg (M_FATAL, "Cipher algorithm '%s' uses a default key size (%d bytes) which is larger than " PACKAGE_NAME "'s current maximum key size (%d bytes)",
-	 ciphername,
-	 EVP_CIPHER_key_length (cipher),
-	 MAX_CIPHER_KEY_LENGTH);
-  return cipher;
-}
-
-static const EVP_MD *
-get_md (const char *digest)
-{
-  const EVP_MD *md = NULL;
-  ASSERT (digest);
-  md = EVP_get_digestbyname (digest);
-  if (!md)
-    msg (M_SSLERR, "Message hash algorithm '%s' not found", digest);
-  if (EVP_MD_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,
-	 EVP_MD_size (md),
-	 MAX_HMAC_KEY_LENGTH);
-  return md;
-}
-
-static void
-init_cipher (EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
-	     struct key *key, const struct key_type *kt, int enc,
-	     const char *prefix)
-{
-  struct gc_arena gc = gc_new ();
-
-  EVP_CIPHER_CTX_init (ctx);
-  if (!EVP_CipherInit_ov (ctx, cipher, NULL, NULL, enc))
-    msg (M_SSLERR, "EVP cipher init #1");
-#ifdef HAVE_EVP_CIPHER_CTX_SET_KEY_LENGTH
-  if (!EVP_CIPHER_CTX_set_key_length (ctx, kt->cipher_length))
-    msg (M_SSLERR, "EVP set key size");
-#endif
-  if (!EVP_CipherInit_ov (ctx, NULL, key->cipher, NULL, enc))
-    msg (M_SSLERR, "EVP cipher init #2");
-
-  msg (D_HANDSHAKE, "%s: Cipher '%s' initialized with %d bit key",
-       prefix,
-       OBJ_nid2sn (EVP_CIPHER_CTX_nid (ctx)),
-       EVP_CIPHER_CTX_key_length (ctx) * 8);
-
-  /* make sure we used a big enough key */
-  ASSERT (EVP_CIPHER_CTX_key_length (ctx) <= kt->cipher_length);
-
-  dmsg (D_SHOW_KEYS, "%s: CIPHER KEY: %s", prefix,
-       format_hex (key->cipher, kt->cipher_length, 0, &gc));
-  dmsg (D_CRYPTO_DEBUG, "%s: CIPHER block_size=%d iv_size=%d",
-       prefix,
-       EVP_CIPHER_CTX_block_size (ctx),
-       EVP_CIPHER_CTX_iv_length (ctx));
-
-  gc_free (&gc);
-}
-
-static void
-init_hmac (HMAC_CTX *ctx, const EVP_MD *digest,
-	   struct key *key, const struct key_type *kt, const char *prefix)
-{
-  struct gc_arena gc = gc_new ();
-
-  HMAC_CTX_init (ctx);
-  HMAC_Init_ex (ctx, key->hmac, kt->hmac_length, digest, NULL);
-  msg (D_HANDSHAKE,
-       "%s: Using %d bit message hash '%s' for HMAC authentication",
-       prefix, HMAC_size (ctx) * 8, OBJ_nid2sn (EVP_MD_type (digest)));
-
-  /* make sure we used a big enough key */
-  ASSERT (HMAC_size (ctx) <= kt->hmac_length);
-
-  dmsg (D_SHOW_KEYS, "%s: HMAC KEY: %s", prefix,
-       format_hex (key->hmac, kt->hmac_length, 0, &gc));
-  dmsg (D_CRYPTO_DEBUG, "%s: HMAC size=%d block_size=%d",
-       prefix,
-       EVP_MD_size (digest),
-       EVP_MD_block_size (digest));
-
-  gc_free (&gc);
-}
-
-/*
- * Build a struct key_type.
- */
-void
-init_key_type (struct key_type *kt, const char *ciphername,
-	       bool ciphername_defined, const char *authname,
-	       bool authname_defined, int keysize,
-	       bool cfb_ofb_allowed, bool warn)
-{
-  CLEAR (*kt);
-  if (ciphername && ciphername_defined)
-    {
-      kt->cipher = get_cipher (ciphername);
-      kt->cipher_length = EVP_CIPHER_key_length (kt->cipher);
-      if (keysize > 0 && keysize <= MAX_CIPHER_KEY_LENGTH)
-	kt->cipher_length = keysize;
-
-      /* check legal cipher mode */
-      {
-	const unsigned int mode = EVP_CIPHER_mode (kt->cipher);
-	if (!(mode == EVP_CIPH_CBC_MODE
-#ifdef ALLOW_NON_CBC_CIPHERS
-	      || (cfb_ofb_allowed && (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE))
-#endif
-	      ))
-#ifdef ENABLE_SMALL
-	  msg (M_FATAL, "Cipher '%s' mode not supported", ciphername);
-#else
-	  msg (M_FATAL, "Cipher '%s' uses a mode not supported by " PACKAGE_NAME " in your current configuration.  CBC mode is always supported, while CFB and OFB modes are supported only when using SSL/TLS authentication and key exchange mode, and when " PACKAGE_NAME " has been built with ALLOW_NON_CBC_CIPHERS.", ciphername);
-#endif
-      }
-    }
-  else
-    {
-      if (warn)
-	msg (M_WARN, "******* WARNING *******: null cipher specified, no encryption will be used");
-    }
-  if (authname && authname_defined)
-    {
-      kt->digest = get_md (authname);
-      kt->hmac_length = EVP_MD_size (kt->digest);
-    }
-  else
-    {
-      if (warn)
-	msg (M_WARN, "******* WARNING *******: null MAC specified, no authentication will be used");
-    }
-}
-
-const char *
-kt_cipher_name (const struct key_type *kt)
-{
-  if (kt->cipher)
-    return EVP_CIPHER_name (kt->cipher);
-  else
-    return "[null-cipher]";
-}
-
-const char *
-kt_digest_name (const struct key_type *kt)
-{
-  if (kt->digest)
-    return EVP_MD_name (kt->digest);
-  else
-    return "[null-digest]";
-}
-
-int
-kt_key_size (const struct key_type *kt)
-{
-  if (kt->cipher_length)
-    return kt->cipher_length * 8;
-  else if (kt->cipher)
-    return EVP_CIPHER_key_length (kt->cipher) * 8;
-  else
-    return 0;
-}
-
-/* given a key and key_type, build a key_ctx */
-void
-init_key_ctx (struct key_ctx *ctx, struct key *key,
-	      const struct key_type *kt, int enc,
-	      const char *prefix)
-{
-  CLEAR (*ctx);
-  if (kt->cipher && kt->cipher_length > 0)
-    {
-      ALLOC_OBJ (ctx->cipher, EVP_CIPHER_CTX);
-      init_cipher (ctx->cipher, kt->cipher, key, kt, enc, prefix);
-    }
-  if (kt->digest && kt->hmac_length > 0)
-    {
-      ALLOC_OBJ (ctx->hmac, HMAC_CTX);
-      init_hmac (ctx->hmac, kt->digest, key, kt, prefix);
-    }
-}
-
-void
-free_key_ctx (struct key_ctx *ctx)
-{
-  if (ctx->cipher)
-    {
-      EVP_CIPHER_CTX_cleanup (ctx->cipher);
-      free (ctx->cipher);
-      ctx->cipher = NULL;
-    }
-  if (ctx->hmac)
-    {
-      HMAC_CTX_cleanup (ctx->hmac);
-      free (ctx->hmac);
-      ctx->hmac = NULL;
-    }
-}
-
-void
-free_key_ctx_bi (struct key_ctx_bi *ctx)
-{
-  free_key_ctx(&ctx->encrypt);
-  free_key_ctx(&ctx->decrypt);
-}
-
-/*
- * Return number of DES cblocks for the current
- * key type or 0 if not a DES cipher.
- */
-static int
-n_DES_cblocks (const struct key_type *kt)
-{
-  int ret = 0;
-  const char *name = OBJ_nid2sn (EVP_CIPHER_nid (kt->cipher));
-  if (name)
-    {
-      if (!strncmp (name, "DES-", 4))
-	{
-	  ret = EVP_CIPHER_key_length (kt->cipher) / sizeof (DES_cblock);
-	}
-      else if (!strncmp (name, "DESX-", 5))
-	{
-	  ret = 1;
-	}
-    }
-  dmsg (D_CRYPTO_DEBUG, "CRYPTO INFO: n_DES_cblocks=%d", ret);
-  return ret;
-}
-
-static bool
-check_key_DES (struct key *key, const struct key_type *kt, int ndc)
-{
-  int i;
-  struct buffer b;
-
-  buf_set_read (&b, key->cipher, kt->cipher_length);
-
-  for (i = 0; i < ndc; ++i)
-    {
-      DES_cblock *dc = (DES_cblock*) buf_read_alloc (&b, sizeof (DES_cblock));
-      if (!dc)
-	{
-	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: insufficient key material");
-	  goto err;
-	}
-      if (DES_is_weak_key(dc))
-	{
-	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: weak key detected");
-	  goto err;
-	}
-      if (!DES_check_key_parity (dc))
-	{
-	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: bad parity detected");
-	  goto err;
-	}
-    }
-  return true;
-
- err:
-  ERR_clear_error ();
-  return false;
-}
-
-static void
-fixup_key_DES (struct key *key, const struct key_type *kt, int ndc)
-{
-  int i;
-  struct buffer b;
-
-  buf_set_read (&b, key->cipher, kt->cipher_length);
-  for (i = 0; i < ndc; ++i)
-    {
-      DES_cblock *dc = (DES_cblock*) buf_read_alloc(&b, sizeof(DES_cblock));
-      if (!dc)
-	{
-	  msg (D_CRYPT_ERRORS, "CRYPTO INFO: fixup_key_DES: insufficient key material");
-	  ERR_clear_error ();
-	  return;
-	}
-      DES_set_odd_parity (dc);
-    }
-}
-
-static bool
-key_is_zero (struct key *key, const struct key_type *kt)
-{
-  int i;
-  for (i = 0; i < kt->cipher_length; ++i)
-    if (key->cipher[i])
-      return false;
-  msg (D_CRYPT_ERRORS, "CRYPTO INFO: WARNING: zero key detected");
-  return true;
-}
-
-/*
- * Make sure that cipher key is a valid key for current key_type.
- */
-bool
-check_key (struct key *key, const struct key_type *kt)
-{
-  if (kt->cipher)
-    {
-      /*
-       * Check for zero key
-       */
-      if (key_is_zero(key, kt))
-	return false;
-
-      /*
-       * Check for weak or semi-weak DES keys.
-       */
-      {
-	const int ndc = n_DES_cblocks (kt);
-	if (ndc)
-	  return check_key_DES (key, kt, ndc);
-	else
-	  return true;
-      }
-    }
-  return true;
-}
-
-/*
- * Make safe mutations to key to ensure it is valid,
- * such as ensuring correct parity on DES keys.
- *
- * This routine cannot guarantee it will generate a good
- * key.  You must always call check_key after this routine
- * to make sure.
- */ 
-void
-fixup_key (struct key *key, const struct key_type *kt)
-{
-  struct gc_arena gc = gc_new ();
-  if (kt->cipher)
-    {
-#ifdef ENABLE_DEBUG
-      const struct key orig = *key;
-#endif
-      const int ndc = n_DES_cblocks (kt);
-
-      if (ndc)
-	fixup_key_DES (key, kt, ndc);
-
-#ifdef ENABLE_DEBUG
-      if (check_debug_level (D_CRYPTO_DEBUG))
-	{
-	  if (memcmp (orig.cipher, key->cipher, kt->cipher_length))
-	    dmsg (D_CRYPTO_DEBUG, "CRYPTO INFO: fixup_key: before=%s after=%s",
-		 format_hex (orig.cipher, kt->cipher_length, 0, &gc),
-		 format_hex (key->cipher, kt->cipher_length, 0, &gc));
-	}
-#endif
-    }
-  gc_free (&gc);
-}
-
-void
-check_replay_iv_consistency (const struct key_type *kt, bool packet_id, bool use_iv)
-{
-  if (cfb_ofb_mode (kt) && !(packet_id && use_iv))
-    msg (M_FATAL, "--no-replay or --no-iv cannot be used with a CFB or OFB mode cipher");
-}
-
-bool
-cfb_ofb_mode (const struct key_type* kt)
-{
-  if (kt->cipher) {
-    const unsigned int mode = EVP_CIPHER_mode (kt->cipher);
-    return mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE;
-  } else
-    return false;
-}
-
-/*
- * Generate a random key.  If key_type is provided, make
- * sure generated key is valid for key_type.
- */
-void
-generate_key_random (struct key *key, const struct key_type *kt)
-{
-  int cipher_len = MAX_CIPHER_KEY_LENGTH;
-  int hmac_len = MAX_HMAC_KEY_LENGTH;
-
-  struct gc_arena gc = gc_new ();
-
-  do {
-    CLEAR (*key);
-    if (kt)
-      {
-	if (kt->cipher && kt->cipher_length > 0 && kt->cipher_length <= cipher_len)
-	  cipher_len = kt->cipher_length;
-
-	if (kt->digest && kt->hmac_length > 0 && kt->hmac_length <= hmac_len)
-	  hmac_len = kt->hmac_length;
-      }
-    if (!RAND_bytes (key->cipher, cipher_len)
-	|| !RAND_bytes (key->hmac, hmac_len))
-      msg (M_FATAL, "ERROR: Random number generator cannot obtain entropy for key generation");
-
-    dmsg (D_SHOW_KEY_SOURCE, "Cipher source entropy: %s", format_hex (key->cipher, cipher_len, 0, &gc));
-    dmsg (D_SHOW_KEY_SOURCE, "HMAC source entropy: %s", format_hex (key->hmac, hmac_len, 0, &gc));
-
-    if (kt)
-      fixup_key (key, kt);
-  } while (kt && !check_key (key, kt));
-
-  gc_free (&gc);
-}
-
-/*
- * Print key material
- */
-void
-key2_print (const struct key2* k,
-	    const struct key_type *kt,
-	    const char* prefix0,
-	    const char* prefix1)
-{
-  struct gc_arena gc = gc_new ();
-  ASSERT (k->n == 2);
-  dmsg (D_SHOW_KEY_SOURCE, "%s (cipher): %s",
-       prefix0,
-       format_hex (k->keys[0].cipher, kt->cipher_length, 0, &gc));
-  dmsg (D_SHOW_KEY_SOURCE, "%s (hmac): %s",
-       prefix0,
-       format_hex (k->keys[0].hmac, kt->hmac_length, 0, &gc));
-  dmsg (D_SHOW_KEY_SOURCE, "%s (cipher): %s",
-       prefix1,
-       format_hex (k->keys[1].cipher, kt->cipher_length, 0, &gc));
-  dmsg (D_SHOW_KEY_SOURCE, "%s (hmac): %s",
-       prefix1,
-       format_hex (k->keys[1].hmac, kt->hmac_length, 0, &gc));
-  gc_free (&gc);
-}
-
-void
-test_crypto (const struct crypto_options *co, struct frame* frame)
-{
-  int i, j;
-  struct gc_arena gc = gc_new ();
-  struct buffer src = alloc_buf_gc (TUN_MTU_SIZE (frame), &gc);
-  struct buffer work = alloc_buf_gc (BUF_SIZE (frame), &gc);
-  struct buffer encrypt_workspace = alloc_buf_gc (BUF_SIZE (frame), &gc);
-  struct buffer decrypt_workspace = alloc_buf_gc (BUF_SIZE (frame), &gc);
-  struct buffer buf = clear_buf();
-
-  /* init work */
-  ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
-
-  msg (M_INFO, "Entering " PACKAGE_NAME " crypto self-test mode.");
-  for (i = 1; i <= TUN_MTU_SIZE (frame); ++i)
-    {
-      update_time ();
-
-      msg (M_INFO, "TESTING ENCRYPT/DECRYPT of packet length=%d", i);
-
-      /*
-       * Load src with random data.
-       */
-      ASSERT (buf_init (&src, 0));
-      ASSERT (i <= src.capacity);
-      src.len = i;
-      ASSERT (RAND_pseudo_bytes (BPTR (&src), BLEN (&src)));
-
-      /* copy source to input buf */
-      buf = work;
-      memcpy (buf_write_alloc (&buf, BLEN (&src)), BPTR (&src), BLEN (&src));
-
-      /* encrypt */
-      openvpn_encrypt (&buf, encrypt_workspace, co, frame);
-
-      /* decrypt */
-      openvpn_decrypt (&buf, decrypt_workspace, co, frame);
-
-      /* compare */
-      if (buf.len != src.len)
-	msg (M_FATAL, "SELF TEST FAILED, src.len=%d buf.len=%d", src.len, buf.len);
-      for (j = 0; j < i; ++j)
-	{
-	  const uint8_t in = *(BPTR (&src) + j);
-	  const uint8_t out = *(BPTR (&buf) + j);
-	  if (in != out)
-	    msg (M_FATAL, "SELF TEST FAILED, pos=%d in=%d out=%d", j, in, out);
-	}
-    }
-  msg (M_INFO, PACKAGE_NAME " crypto self-test mode SUCCEEDED.");
-  gc_free (&gc);
-}
-
-#ifdef USE_SSL
-
-void
-get_tls_handshake_key (const struct key_type *key_type,
-		       struct key_ctx_bi *ctx,
-		       const char *passphrase_file,
-		       const int key_direction,
-		       const unsigned int flags)
-{
-  if (passphrase_file && key_type->hmac_length)
-    {
-      struct key2 key2;
-      struct key_type kt = *key_type;
-      struct key_direction_state kds;
-
-      /* for control channel we are only authenticating, not encrypting */
-      kt.cipher_length = 0;
-      kt.cipher = NULL;
-
-#if ENABLE_INLINE_FILES
-      if (flags & GHK_INLINE)
-	{
-	  /* key was specified inline, key text is in passphrase_file */
-	  read_key_file (&key2, passphrase_file, RKF_INLINE|RKF_MUST_SUCCEED);
-
-	  /* succeeded? */
-	  if (key2.n == 2)
-	    msg (M_INFO, "Control Channel Authentication: tls-auth using INLINE static key file");
-	  else
-	    msg (M_FATAL, "INLINE tls-auth file lacks the requisite 2 keys");
-	}
-      else
-#endif
-      {
-	/* first try to parse as an OpenVPN static key file */
-	read_key_file (&key2, passphrase_file, 0);
-
-	/* succeeded? */
-	if (key2.n == 2)
-	  {
-	    msg (M_INFO,
-		 "Control Channel Authentication: using '%s' as a " PACKAGE_NAME " static key file",
-		 passphrase_file);
-	  }
-	else
-	  {
-	    int hash_size;
-
-	    CLEAR (key2);
-
-	    /* failed, now try to get hash from a freeform file */
-	    hash_size = read_passphrase_hash (passphrase_file,
-					      kt.digest,
-					      key2.keys[0].hmac,
-					      MAX_HMAC_KEY_LENGTH);
-	    ASSERT (hash_size == kt.hmac_length);
-
-	    /* suceeded */
-	    key2.n = 1;
-
-	    msg (M_INFO,
-		 "Control Channel Authentication: using '%s' as a free-form passphrase file",
-		 passphrase_file);
-	  }
-      }
-      /* handle key direction */
-
-      key_direction_state_init (&kds, key_direction);
-      must_have_n_keys (passphrase_file, "tls-auth", &key2, kds.need_keys);
-
-      /* initialize hmac key in both directions */
-
-      init_key_ctx (&ctx->encrypt, &key2.keys[kds.out_key], &kt, DO_ENCRYPT,
-		    "Outgoing Control Channel Authentication");
-      init_key_ctx (&ctx->decrypt, &key2.keys[kds.in_key], &kt, DO_DECRYPT,
-		    "Incoming Control Channel Authentication");
-
-      CLEAR (key2);
-    }
-  else
-    {
-      CLEAR (*ctx);
-    }
-}
-#endif
-
-/* header and footer for static key file */
-static const char static_key_head[] = "-----BEGIN OpenVPN Static key V1-----";
-static const char static_key_foot[] = "-----END OpenVPN Static key V1-----";
-
-static const char printable_char_fmt[] =
-  "Non-Hex character ('%c') found at line %d in key file '%s' (%d/%d/%d bytes found/min/max)";
-
-static const char unprintable_char_fmt[] =
-  "Non-Hex, unprintable character (0x%02x) found at line %d in key file '%s' (%d/%d/%d bytes found/min/max)";
-
-/* read key from file */
-
-void
-read_key_file (struct key2 *key2, const char *file, const unsigned int flags)
-{
-  struct gc_arena gc = gc_new ();
-  struct buffer in;
-  int fd, size;
-  uint8_t hex_byte[3] = {0, 0, 0};
-  const char *error_filename = file;
-
-  /* parse info */
-  const unsigned char *cp;
-  int hb_index = 0;
-  int line_num = 1;
-  int line_index = 0;
-  int match = 0;
-
-  /* output */
-  uint8_t* out = (uint8_t*) &key2->keys;
-  const int keylen = sizeof (key2->keys);
-  int count = 0;
-
-  /* parse states */
-# define PARSE_INITIAL        0
-# define PARSE_HEAD           1
-# define PARSE_DATA           2
-# define PARSE_DATA_COMPLETE  3
-# define PARSE_FOOT           4
-# define PARSE_FINISHED       5
-  int state = PARSE_INITIAL;
-
-  /* constants */
-  const int hlen = strlen (static_key_head);
-  const int flen = strlen (static_key_foot);
-  const int onekeylen = sizeof (key2->keys[0]);
-
-  CLEAR (*key2);
-
-  /*
-   * Key can be provided as a filename in 'file' or if RKF_INLINE
-   * is set, the actual key data itself in ascii form.
-   */
-#if ENABLE_INLINE_FILES
-  if (flags & RKF_INLINE) /* 'file' is a string containing ascii representation of key */
-    {
-      size = strlen (file) + 1;
-      buf_set_read (&in, (const uint8_t *)file, size);
-      error_filename = INLINE_FILE_TAG;
-    }
-  else /* 'file' is a filename which refers to a file containing the ascii key */
-#endif
-    {
-      in = alloc_buf_gc (2048, &gc);
-      fd = open (file, O_RDONLY);
-      if (fd == -1)
-	msg (M_ERR, "Cannot open file key file '%s'", file);
-      size = read (fd, in.data, in.capacity);
-      if (size < 0)
-	msg (M_FATAL, "Read error on key file ('%s')", file);
-      if (size == in.capacity)
-	msg (M_FATAL, "Key file ('%s') can be a maximum of %d bytes", file, (int)in.capacity);
-      close (fd);
-    }
-
-  cp = (unsigned char *)in.data;
-  while (size > 0)
-    {
-      const unsigned char c = *cp;
-
-#if 0
-      msg (M_INFO, "char='%c'[%d] s=%d ln=%d li=%d m=%d c=%d",
-	   c, (int)c, state, line_num, line_index, match, count);
-#endif
-
-      if (c == '\n')
-	{
-	  line_index = match = 0;
-	  ++line_num;	      
-	}
-      else
-	{
-	  /* first char of new line */
-	  if (!line_index)
-	    {
-	      /* first char of line after header line? */
-	      if (state == PARSE_HEAD)
-		state = PARSE_DATA;
-
-	      /* first char of footer */
-	      if ((state == PARSE_DATA || state == PARSE_DATA_COMPLETE) && c == '-')
-		state = PARSE_FOOT;
-	    }
-
-	  /* compare read chars with header line */
-	  if (state == PARSE_INITIAL)
-	    {
-	      if (line_index < hlen && c == static_key_head[line_index])
-		{
-		  if (++match == hlen)
-		    state = PARSE_HEAD;
-		}
-	    }
-
-	  /* compare read chars with footer line */
-	  if (state == PARSE_FOOT)
-	    {
-	      if (line_index < flen && c == static_key_foot[line_index])
-		{
-		  if (++match == flen)
-		    state = PARSE_FINISHED;
-		}
-	    }
-
-	  /* reading key */
-	  if (state == PARSE_DATA)
-	    {
-	      if (isxdigit(c))
-		{
-		  ASSERT (hb_index >= 0 && hb_index < 2);
-		  hex_byte[hb_index++] = c;
-		  if (hb_index == 2)
-		    {
-		      unsigned int u;
-		      ASSERT(sscanf((const char *)hex_byte, "%x", &u) == 1);
-		      *out++ = u;
-		      hb_index = 0;
-		      if (++count == keylen)
-			state = PARSE_DATA_COMPLETE;
-		    }
-		}
-	      else if (isspace(c))
-		;
-	      else
-		{
-		  msg (M_FATAL,
-		       (isprint (c) ? printable_char_fmt : unprintable_char_fmt),
-		       c, line_num, error_filename, count, onekeylen, keylen);
-		}
-	    }
-	  ++line_index;
-	}
-      ++cp;
-      --size;
-    }
-
-  /*
-   * Normally we will read either 1 or 2 keys from file.
-   */
-  key2->n = count / onekeylen;
-
-  ASSERT (key2->n >= 0 && key2->n <= (int) SIZE (key2->keys));
-
-  if (flags & RKF_MUST_SUCCEED)
-    {
-      if (!key2->n)
-	msg (M_FATAL, "Insufficient key material or header text not found in file '%s' (%d/%d/%d bytes found/min/max)",
-	     error_filename, count, onekeylen, keylen);
-
-      if (state != PARSE_FINISHED)
-	msg (M_FATAL, "Footer text not found in file '%s' (%d/%d/%d bytes found/min/max)",
-	     error_filename, count, onekeylen, keylen);
-    }
-
-  /* zero file read buffer if not an inline file */
-#if ENABLE_INLINE_FILES
-  if (!(flags & RKF_INLINE))
-#endif
-    buf_clear (&in);
-
-  if (key2->n)
-    warn_if_group_others_accessible (error_filename);
-
-#if 0
-  /* DEBUGGING */
-  {
-    int i;
-    printf ("KEY READ, n=%d\n", key2->n);
-    for (i = 0; i < (int) SIZE (key2->keys); ++i)
-      {
-	/* format key as ascii */
-	const char *fmt = format_hex_ex ((const uint8_t*)&key2->keys[i],
-					 sizeof (key2->keys[i]),
-					 0,
-					 16,
-					 "\n",
-					 &gc);
-	printf ("[%d]\n%s\n\n", i, fmt);
-      }
-  }
-#endif
-
-  /* pop our garbage collection level */
-  gc_free (&gc);
-}
-
-int
-read_passphrase_hash (const char *passphrase_file,
-		      const EVP_MD *digest,
-		      uint8_t *output,
-		      int len)
-{
-  unsigned int outlen = 0;
-  EVP_MD_CTX md;
-
-  ASSERT (len >= EVP_MD_size (digest));
-  memset (output, 0, len);
-
-  EVP_DigestInit (&md, digest);
-
-  /* read passphrase file */
-  {
-    const int min_passphrase_size = 8;
-    uint8_t buf[64];
-    int total_size = 0;
-    int fd = open (passphrase_file, O_RDONLY);
-
-    if (fd == -1)
-      msg (M_ERR, "Cannot open passphrase file: '%s'", passphrase_file);
-
-    for (;;)
-      {
-	int size = read (fd, buf, sizeof (buf));
-	if (size == 0)
-	  break;
-	if (size == -1)
-	  msg (M_ERR, "Read error on passphrase file: '%s'",
-	       passphrase_file);
-	EVP_DigestUpdate (&md, buf, size);
-	total_size += size;
-      }
-    close (fd);
-
-    warn_if_group_others_accessible (passphrase_file);
-
-    if (total_size < min_passphrase_size)
-      msg (M_FATAL,
-	   "Passphrase file '%s' is too small (must have at least %d characters)",
-	   passphrase_file, min_passphrase_size);
-  }
-
-  EVP_DigestFinal (&md, output, &outlen);
-  EVP_MD_CTX_cleanup (&md);
-  return outlen;
-}
-
-/*
- * Write key to file, return number of random bits
- * written.
- */
-int
-write_key_file (const int nkeys, const char *filename)
-{
-  struct gc_arena gc = gc_new ();
-
-  int fd, i;
-  int nbits = 0;
-
-  /* must be large enough to hold full key file */
-  struct buffer out = alloc_buf_gc (2048, &gc);
-  struct buffer nbits_head_text = alloc_buf_gc (128, &gc);
-
-  /* how to format the ascii file representation of key */
-  const int bytes_per_line = 16;
-
-  /* open key file */
-  fd = open (filename, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
-
-  if (fd == -1)
-    msg (M_ERR, "Cannot open shared secret file '%s' for write", filename);
-
-  buf_printf (&out, "%s\n", static_key_head);
-
-  for (i = 0; i < nkeys; ++i)
-    {
-      struct key key;
-      char* fmt;
-
-      /* generate random bits */
-      generate_key_random (&key, NULL);
-
-      /* format key as ascii */
-      fmt = format_hex_ex ((const uint8_t*)&key,
-			   sizeof (key),
-			   0,
-			   bytes_per_line,
-			   "\n",
-			   &gc);
-
-      /* increment random bits counter */
-      nbits += sizeof (key) * 8;
-
-      /* write to holding buffer */
-      buf_printf (&out, "%s\n", fmt);
-
-      /* zero memory which held key component (will be freed by GC) */
-      memset (fmt, 0, strlen(fmt));
-      CLEAR (key);
-    }
-
-  buf_printf (&out, "%s\n", static_key_foot);
-
-  /* write number of bits */
-  buf_printf (&nbits_head_text, "#\n# %d bit OpenVPN static key\n#\n", nbits);
-  buf_write_string_file (&nbits_head_text, filename, fd);
-
-  /* write key file, now formatted in out, to file */
-  buf_write_string_file (&out, filename, fd);
-
-  if (close (fd))
-    msg (M_ERR, "Close error on shared secret file %s", filename);
-
-  /* zero memory which held file content (memory will be freed by GC) */
-  buf_clear (&out);
-
-  /* pop our garbage collection level */
-  gc_free (&gc);
-
-  return nbits;
-}
-
-void
-must_have_n_keys (const char *filename, const char *option, const struct key2 *key2, int n)
-{
-  if (key2->n < n)
-    {
-#ifdef ENABLE_SMALL
-      msg (M_FATAL, "Key file '%s' used in --%s contains insufficient key material [keys found=%d required=%d]", filename, option, key2->n, n);
-#else
-      msg (M_FATAL, "Key file '%s' used in --%s contains insufficient key material [keys found=%d required=%d] -- try generating a new key file with '" PACKAGE " --genkey --secret [file]', or use the existing key file in bidirectional mode by specifying --%s without a key direction parameter", filename, option, key2->n, n, option);
-#endif
-    }
-}
-
-int
-ascii2keydirection (int msglevel, const char *str)
-{
-  if (!str)
-    return KEY_DIRECTION_BIDIRECTIONAL;
-  else if (!strcmp (str, "0"))
-    return KEY_DIRECTION_NORMAL;
-  else if (!strcmp (str, "1"))
-    return KEY_DIRECTION_INVERSE;
-  else
-    {
-      msg (msglevel, "Unknown key direction '%s' -- must be '0' or '1'", str);
-      return -1;
-    }
-  return KEY_DIRECTION_BIDIRECTIONAL; /* NOTREACHED */
-}
-
-const char *
-keydirection2ascii (int kd, bool remote)
-{
-  if (kd == KEY_DIRECTION_BIDIRECTIONAL)
-    return NULL;
-  else if (kd == KEY_DIRECTION_NORMAL)
-    return remote ? "1" : "0";
-  else if (kd == KEY_DIRECTION_INVERSE)
-    return remote ? "0" : "1";
-  else
-    {
-      ASSERT (0);
-    }
-  return NULL; /* NOTREACHED */
-}
-
-void
-key_direction_state_init (struct key_direction_state *kds, int key_direction)
-{
-  CLEAR (*kds);
-  switch (key_direction)
-    {
-    case KEY_DIRECTION_NORMAL:
-      kds->out_key = 0;
-      kds->in_key = 1;
-      kds->need_keys = 2;
-      break;
-    case KEY_DIRECTION_INVERSE:
-      kds->out_key = 1;
-      kds->in_key = 0;
-      kds->need_keys = 2;
-      break;
-    case KEY_DIRECTION_BIDIRECTIONAL:
-      kds->out_key = 0;
-      kds->in_key = 0;
-      kds->need_keys = 1;
-      break;
-    default:
-      ASSERT (0);
-    }
-}
-
-void
-verify_fix_key2 (struct key2 *key2, const struct key_type *kt, const char *shared_secret_file)
-{
-  int i;
-
-  for (i = 0; i < key2->n; ++i)
-    {
-      /* Fix parity for DES keys and make sure not a weak key */
-      fixup_key (&key2->keys[i], kt);
-
-      /* This should be a very improbable failure */
-      if (!check_key (&key2->keys[i], kt))
-	msg (M_FATAL, "Key #%d in '%s' is bad.  Try making a new key with --genkey.",
-	     i+1, shared_secret_file);
-    }
-}
-
-/* given a key and key_type, write key to buffer */
-bool
-write_key (const struct key *key, const struct key_type *kt,
-	   struct buffer *buf)
-{
-  ASSERT (kt->cipher_length <= MAX_CIPHER_KEY_LENGTH
-	  && kt->hmac_length <= MAX_HMAC_KEY_LENGTH);
-
-  if (!buf_write (buf, &kt->cipher_length, 1))
-    return false;
-  if (!buf_write (buf, &kt->hmac_length, 1))
-    return false;
-  if (!buf_write (buf, key->cipher, kt->cipher_length))
-    return false;
-  if (!buf_write (buf, key->hmac, kt->hmac_length))
-    return false;
-
-  return true;
-}
-
-/*
- * Given a key_type and buffer, read key from buffer.
- * Return: 1 on success
- *        -1 read failure
- *         0 on key length mismatch 
- */
-int
-read_key (struct key *key, const struct key_type *kt, struct buffer *buf)
-{
-  uint8_t cipher_length;
-  uint8_t hmac_length;
-
-  CLEAR (*key);
-  if (!buf_read (buf, &cipher_length, 1))
-    goto read_err;
-  if (!buf_read (buf, &hmac_length, 1))
-    goto read_err;
-
-  if (!buf_read (buf, key->cipher, cipher_length))
-    goto read_err;
-  if (!buf_read (buf, key->hmac, hmac_length))
-    goto read_err;
-
-  if (cipher_length != kt->cipher_length || hmac_length != kt->hmac_length)
-    goto key_len_err;
-
-  return 1;
-
-read_err:
-  msg (D_TLS_ERRORS, "TLS Error: error reading key from remote");
-  return -1;
-
-key_len_err:
-  msg (D_TLS_ERRORS,
-       "TLS Error: key length mismatch, local cipher/hmac %d/%d, remote cipher/hmac %d/%d",
-       kt->cipher_length, kt->hmac_length, cipher_length, hmac_length);
-  return 0;
-}
-
-void
-show_available_ciphers ()
-{
-  int nid;
-
-
-#ifndef ENABLE_SMALL
-  printf ("The following ciphers and cipher modes are available\n"
-	  "for use with " PACKAGE_NAME ".  Each cipher shown below may be\n"
-	  "used as a parameter to the --cipher option.  The default\n"
-	  "key size is shown as well as whether or not it can be\n"
-          "changed with the --keysize directive.  Using a CBC mode\n"
-	  "is recommended.\n\n");
-#endif
-
-  for (nid = 0; nid < 10000; ++nid)	/* is there a better way to get the size of the nid list? */
-    {
-      const EVP_CIPHER *cipher = EVP_get_cipherbynid (nid);
-      if (cipher && cipher_ok (OBJ_nid2sn (nid)))
-	{
-	  const unsigned int mode = EVP_CIPHER_mode (cipher);
-	  if (mode == EVP_CIPH_CBC_MODE
-#ifdef ALLOW_NON_CBC_CIPHERS
-	      || mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE
-#endif
-	      )
-	    printf ("%s %d bit default key (%s)\n",
-		    OBJ_nid2sn (nid),
-		    EVP_CIPHER_key_length (cipher) * 8,
-		    ((EVP_CIPHER_flags (cipher) & EVP_CIPH_VARIABLE_LENGTH) ?
-		     "variable" : "fixed"));
-	}
-    }
-  printf ("\n");
-}
-
-void
-show_available_digests ()
-{
-  int nid;
-
-#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
-
-  for (nid = 0; nid < 10000; ++nid)
-    {
-      const EVP_MD *digest = EVP_get_digestbynid (nid);
-      if (digest)
-	{
-	  printf ("%s %d bit digest size\n",
-		  OBJ_nid2sn (nid), EVP_MD_size (digest) * 8);
-	}
-    }
-  printf ("\n");
-}
-
-void
-show_available_engines ()
-{
-#if CRYPTO_ENGINE
-  ENGINE *e;
-
-  printf ("OpenSSL Crypto Engines\n\n");
-
-  ENGINE_load_builtin_engines ();
-
-  e = ENGINE_get_first ();
-  while (e)
-    {
-      printf ("%s [%s]\n",
-	      ENGINE_get_name (e),
-	      ENGINE_get_id (e));
-      e = ENGINE_get_next (e);
-    }
-  ENGINE_cleanup ();
-#else
-  printf ("Sorry, OpenSSL hardware crypto engine functionality is not available.\n");
-#endif
-}
-
-/*
- * Enable crypto acceleration, if available
- */
-
-static bool engine_initialized = false; /* GLOBAL */
-
-#if CRYPTO_ENGINE
-
-static ENGINE *engine_persist = NULL;   /* GLOBAL */
-
-/* Try to load an engine in a shareable library */
-static ENGINE *
-try_load_engine (const char *engine)
-{
-  ENGINE *e = ENGINE_by_id ("dynamic");
-  if (e)
-    {
-      if (!ENGINE_ctrl_cmd_string (e, "SO_PATH", engine, 0)
-	  || !ENGINE_ctrl_cmd_string (e, "LOAD", NULL, 0))
-	{
-	  ENGINE_free (e);
-	  e = NULL;
-	}
-    }
-  return e;
-}
-
-static ENGINE *
-setup_engine (const char *engine)
-{
-  ENGINE *e = NULL;
-
-  ENGINE_load_builtin_engines ();
-
-  if (engine)
-    {
-      if (strcmp (engine, "auto") == 0)
-	{
-	  msg (M_INFO, "Initializing OpenSSL auto engine support");
-	  ENGINE_register_all_complete ();
-	  return NULL;
-	}
-      if ((e = ENGINE_by_id (engine)) == NULL
-	 && (e = try_load_engine (engine)) == NULL)
-	{
-	  msg (M_FATAL, "OpenSSL error: cannot load engine '%s'", engine);
-	}
-
-      if (!ENGINE_set_default (e, ENGINE_METHOD_ALL))
-	{
-	  msg (M_FATAL, "OpenSSL error: ENGINE_set_default failed on engine '%s'",
-	       engine);
-	}
-
-      msg (M_INFO, "Initializing OpenSSL support for engine '%s'",
-	   ENGINE_get_id (e));
-    }
-  return e;
-}
-#endif
-
-void
-init_crypto_lib_engine (const char *engine_name)
-{
-  if (!engine_initialized)
-    {
-#if CRYPTO_ENGINE
-      ASSERT (engine_name);
-      ASSERT (!engine_persist);
-      engine_persist = setup_engine (engine_name);
-#else
-      msg (M_WARN, "Note: OpenSSL hardware crypto engine functionality is not available");
-#endif
-      engine_initialized = true;
-    }
-}
-
-/*
- * This routine should have additional OpenSSL crypto library initialisations
- * used by both crypto and ssl components of OpenVPN.
- */
-void init_crypto_lib ()
-{
-}
-
-void uninit_crypto_lib ()
-{
-#if CRYPTO_ENGINE
-  if (engine_initialized)
-    {
-      ENGINE_cleanup ();
-      engine_persist = NULL;
-      engine_initialized = false;
-    }
-#endif
-  prng_uninit ();
-}
-
-/*
- * 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.
- */
-
-static uint8_t *nonce_data; /* GLOBAL */
-static const EVP_MD *nonce_md = NULL; /* GLOBAL */
-static int nonce_secret_len; /* GLOBAL */
-
-void
-prng_init (const char *md_name, const int nonce_secret_len_parm)
-{
-  prng_uninit ();
-  nonce_md = md_name ? get_md (md_name) : NULL;
-  if (nonce_md)
-    {
-      ASSERT (nonce_secret_len_parm >= NONCE_SECRET_LEN_MIN && nonce_secret_len_parm <= NONCE_SECRET_LEN_MAX);
-      nonce_secret_len = nonce_secret_len_parm;
-      {
-	const int size = EVP_MD_size (nonce_md) + nonce_secret_len;
-	dmsg (D_CRYPTO_DEBUG, "PRNG init md=%s size=%d", EVP_MD_name (nonce_md), size);
-	nonce_data = (uint8_t*) malloc (size);
-	check_malloc_return (nonce_data);
-#if 1 /* Must be 1 for real usage */
-	if (!RAND_bytes (nonce_data, size))
-	  msg (M_FATAL, "ERROR: Random number generator cannot obtain entropy for PRNG");
-#else
-	/* Only for testing -- will cause a predictable PRNG sequence */
-	{
-	  int i;
-	  for (i = 0; i < size; ++i)
-	    nonce_data[i] = (uint8_t) i;
-	}
-#endif
-      }
-    }
-}
-
-void
-prng_uninit (void)
-{
-  free (nonce_data);
-  nonce_data = NULL;
-  nonce_md = NULL;
-  nonce_secret_len = 0;
-}
-
-void
-prng_bytes (uint8_t *output, int len)
-{
-  if (nonce_md)
-    {
-      EVP_MD_CTX ctx;
-      const int md_size = EVP_MD_size (nonce_md);
-      while (len > 0)
-	{
-	  unsigned int outlen = 0;
-	  const int blen = min_int (len, md_size);
-	  EVP_DigestInit (&ctx, nonce_md);
-	  EVP_DigestUpdate (&ctx, nonce_data, md_size + nonce_secret_len);
-	  EVP_DigestFinal (&ctx, nonce_data, &outlen);
-	  ASSERT (outlen == md_size);
-	  EVP_MD_CTX_cleanup (&ctx);
-	  memcpy (output, nonce_data, blen);
-	  output += blen;
-	  len -= blen;
-	}
-    }
-  else
-    RAND_bytes (output, len);
-}
-
-/* an analogue to the random() function, but use prng_bytes */
-long int
-get_random()
-{
-  long int l;
-  prng_bytes ((unsigned char *)&l, sizeof(l));
-  if (l < 0)
-    l = -l;
-  return l;
-}
-
-const char *
-md5sum (uint8_t *buf, int len, int n_print_chars, struct gc_arena *gc)
-{
-  uint8_t digest[MD5_DIGEST_LENGTH];
-  MD5 (buf, len, digest);
-  return format_hex (digest, MD5_DIGEST_LENGTH, n_print_chars, gc);
-}
-
-/*
- * OpenSSL memory debugging.  If dmalloc debugging is enabled, tell
- * OpenSSL to use our private malloc/realloc/free functions so that
- * we can dispatch them to dmalloc.
- */
-
-#ifdef DMALLOC
-
-static void *
-crypto_malloc (size_t size, const char *file, int line)
-{
-  return dmalloc_malloc(file, line, size, DMALLOC_FUNC_MALLOC, 0, 0);
-}
-
-static void *
-crypto_realloc (void *ptr, size_t size, const char *file, int line)
-{
-  return dmalloc_realloc(file, line, ptr, size, DMALLOC_FUNC_REALLOC, 0);
-}
-
-static void
-crypto_free (void *ptr)
-{
-  dmalloc_free (__FILE__, __LINE__, ptr, DMALLOC_FUNC_FREE);
-}
-
-void
-openssl_dmalloc_init (void)
-{
-   CRYPTO_set_mem_ex_functions (crypto_malloc,
-				crypto_realloc,
-				crypto_free);
-}
-
-#endif /* DMALLOC */
-
-#ifndef USE_SSL
-
-void
-init_ssl_lib (void)
-{
-  ERR_load_crypto_strings ();
-  OpenSSL_add_all_algorithms ();
-  init_crypto_lib ();
-}
-
-void
-free_ssl_lib (void)
-{
-  uninit_crypto_lib ();
-  EVP_cleanup ();
-  ERR_free_strings ();
-}
-
-#endif /* USE_SSL */
-
-/*
- * md5 functions
- */
-
-void
-md5_state_init (struct md5_state *s)
-{
-  MD5_Init (&s->ctx);
-}
-
-void
-md5_state_update (struct md5_state *s, void *data, size_t len)
-{
-  MD5_Update (&s->ctx, data, len);
-}
-
-void
-md5_state_final (struct md5_state *s, struct md5_digest *out)
-{
-  MD5_Final (out->digest, &s->ctx);
-}
-
-void
-md5_digest_clear (struct md5_digest *digest)
-{
-  CLEAR (*digest);
-}
-
-bool
-md5_digest_defined (const struct md5_digest *digest)
-{
-  int i;
-  for (i = 0; i < MD5_DIGEST_LENGTH; ++i)
-    if (digest->digest[i])
-      return true;
-  return false;
-}
-
-bool
-md5_digest_equal (const struct md5_digest *d1, const struct md5_digest *d2)
-{
-  return memcmp(d1->digest, d2->digest, MD5_DIGEST_LENGTH) == 0;
-}
-
-#endif /* USE_CRYPTO */