Imported Upstream version 2.2.1upstream/2.2.1

1 files changed, 849 insertions, 0 deletions

diff --git a/ssl.h b/ssl.h
new file mode 100644
index 0000000..8464492
--- /dev/null
+++ b/ssl.h
@@ -0,0 +1,849 @@
+/*
+ *  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
+ */
+
+#ifndef OPENVPN_SSL_H
+#define OPENVPN_SSL_H
+
+#if defined(USE_CRYPTO) && defined(USE_SSL)
+
+#include <openssl/ssl.h>
+#include <openssl/bio.h>
+#include <openssl/rand.h>
+#include <openssl/err.h>
+#include <openssl/pkcs12.h>
+#include <openssl/x509v3.h>
+
+#include "basic.h"
+#include "common.h"
+#include "crypto.h"
+#include "packet_id.h"
+#include "session_id.h"
+#include "reliable.h"
+#include "socket.h"
+#include "mtu.h"
+#include "options.h"
+#include "plugin.h"
+
+/*
+ * OpenVPN Protocol, taken from ssl.h in OpenVPN source code.
+ *
+ * TCP/UDP Packet:  This represents the top-level encapsulation.
+ *
+ * TCP/UDP packet format:
+ *
+ *   Packet length (16 bits, unsigned) -- TCP only, always sent as
+ *       plaintext.  Since TCP is a stream protocol, the packet
+ *       length words define the packetization of the stream.
+ *
+ *   Packet opcode/key_id (8 bits) -- TLS only, not used in
+ *       pre-shared secret mode.
+ *            packet message type, a P_* constant (high 5 bits)
+ *            key_id (low 3 bits, see key_id in struct tls_session
+ *              below for comment).  The key_id refers to an
+ *              already negotiated TLS session.  OpenVPN seamlessly
+ *              renegotiates the TLS session by using a new key_id
+ *              for the new session.  Overlap (controlled by
+ *              user definable parameters) between old and new TLS
+ *              sessions is allowed, providing a seamless transition
+ *              during tunnel operation.
+ *
+ *   Payload (n bytes), which may be a P_CONTROL, P_ACK, or P_DATA
+ *       message.
+ *
+ * Message types:
+ *
+ *  P_CONTROL_HARD_RESET_CLIENT_V1 -- Key method 1, initial key from
+ *    client, forget previous state.
+ *
+ *  P_CONTROL_HARD_RESET_SERVER_V1 -- Key method 2, initial key
+ *    from server, forget previous state.
+ *
+ *  P_CONTROL_SOFT_RESET_V1 -- New key, with a graceful transition
+ *    from old to new key in the sense that a transition window
+ *    exists where both the old or new key_id can be used.  OpenVPN
+ *    uses two different forms of key_id.  The first form is 64 bits
+ *    and is used for all P_CONTROL messages.  P_DATA messages on the
+ *    other hand use a shortened key_id of 3 bits for efficiency
+ *    reasons since the vast majority of OpenVPN packets in an
+ *    active tunnel will be P_DATA messages.  The 64 bit form
+ *    is referred to as a session_id, while the 3 bit form is
+ *    referred to as a key_id.
+ *
+ *  P_CONTROL_V1 -- Control channel packet (usually TLS ciphertext).
+ *
+ *  P_ACK_V1 -- Acknowledgement for P_CONTROL packets received.
+ *
+ *  P_DATA_V1 -- Data channel packet containing actual tunnel data
+ *    ciphertext.
+ *
+ *  P_CONTROL_HARD_RESET_CLIENT_V2 -- Key method 2, initial key from
+ *   client, forget previous state.
+ *
+ *  P_CONTROL_HARD_RESET_SERVER_V2 -- Key method 2, initial key from
+ *   server, forget previous state.
+ *
+ * P_CONTROL* and P_ACK Payload:  The P_CONTROL message type
+ * indicates a TLS ciphertext packet which has been encapsulated
+ * inside of a reliability layer.  The reliability layer is
+ * implemented as a straightforward ACK and retransmit model.
+ *
+ * P_CONTROL message format:
+ *
+ *   local session_id (random 64 bit value to identify TLS session).
+ *   HMAC signature of entire encapsulation header for integrity
+ *       check if --tls-auth is specified (usually 16 or 20 bytes).
+ *   packet-id for replay protection (4 or 8 bytes, includes
+ *       sequence number and optional time_t timestamp).
+ *   P_ACK packet_id array length (1 byte).
+ *   P_ACK packet-id array (if length > 0).
+ *   P_ACK remote session_id (if length > 0).
+ *   message packet-id (4 bytes).
+ *   TLS payload ciphertext (n bytes) (only for P_CONTROL).
+ *
+ * Once the TLS session has been initialized and authenticated,
+ * the TLS channel is used to exchange random key material for
+ * bidirectional cipher and HMAC keys which will be
+ * used to secure actual tunnel packets.  OpenVPN currently
+ * implements two key methods.  Key method 1 directly
+ * derives keys using random bits obtained from the RAND_bytes
+ * OpenSSL function.  Key method 2 mixes random key material
+ * from both sides of the connection using the TLS PRF mixing
+ * function.  Key method 2 is the preferred method and is the default
+ * for OpenVPN 2.0.
+ * 
+ * TLS plaintext content:
+ *
+ * TLS plaintext packet (if key_method == 1):
+ *
+ *   Cipher key length in bytes (1 byte).
+ *   Cipher key (n bytes).
+ *   HMAC key length in bytes (1 byte).
+ *   HMAC key (n bytes).
+ *   Options string (n bytes, null terminated, client/server options
+ *       string should match).
+ *
+ * TLS plaintext packet (if key_method == 2):
+ *
+ *   Literal 0 (4 bytes).
+ *   key_method type (1 byte).
+ *   key_source structure (pre_master only defined for client ->
+ *       server).
+ *   options_string_length, including null (2 bytes).
+ *   Options string (n bytes, null terminated, client/server options
+ *       string must match).
+ *   [The username/password data below is optional, record can end
+ *       at this point.]
+ *   username_string_length, including null (2 bytes).
+ *   Username string (n bytes, null terminated).
+ *   password_string_length, including null (2 bytes).
+ *   Password string (n bytes, null terminated).
+ *
+ * The P_DATA payload represents encrypted, encapsulated tunnel
+ * packets which tend to be either IP packets or Ethernet frames.
+ * This is essentially the "payload" of the VPN.
+ *
+ * P_DATA message content:
+ *   HMAC of ciphertext IV + ciphertext (if not disabled by
+ *       --auth none).
+ *   Ciphertext IV (size is cipher-dependent, if not disabled by
+ *       --no-iv).
+ *   Tunnel packet ciphertext.
+ *
+ * P_DATA plaintext
+ *   packet_id (4 or 8 bytes, if not disabled by --no-replay).
+ *       In SSL/TLS mode, 4 bytes are used because the implementation
+ *       can force a TLS renegotation before 2^32 packets are sent.
+ *       In pre-shared key mode, 8 bytes are used (sequence number
+ *       and time_t value) to allow long-term key usage without
+ *       packet_id collisions.
+ *   User plaintext (n bytes).
+ *
+ * Notes:
+ *   (1) ACK messages can be encoded in either the dedicated
+ *       P_ACK record or they can be prepended to a P_CONTROL message.
+ *   (2) P_DATA and P_CONTROL/P_ACK use independent packet-id
+ *       sequences because P_DATA is an unreliable channel while
+ *       P_CONTROL/P_ACK is a reliable channel.  Each use their
+ *       own independent HMAC keys.
+ *   (3) Note that when --tls-auth is used, all message types are
+ *       protected with an HMAC signature, even the initial packets
+ *       of the TLS handshake.  This makes it easy for OpenVPN to
+ *       throw away bogus packets quickly, without wasting resources
+ *       on attempting a TLS handshake which will ultimately fail.
+ */
+
+/* Used in the TLS PRF function */
+#define KEY_EXPANSION_ID "OpenVPN"
+
+/* passwords */
+#define UP_TYPE_AUTH        "Auth"
+#define UP_TYPE_PRIVATE_KEY "Private Key"
+
+/* packet opcode (high 5 bits) and key-id (low 3 bits) are combined in one byte */
+#define P_KEY_ID_MASK                  0x07
+#define P_OPCODE_SHIFT                 3
+
+/* packet opcodes -- the V1 is intended to allow protocol changes in the future */
+#define P_CONTROL_HARD_RESET_CLIENT_V1 1     /* initial key from client, forget previous state */
+#define P_CONTROL_HARD_RESET_SERVER_V1 2     /* initial key from server, forget previous state */
+#define P_CONTROL_SOFT_RESET_V1        3     /* new key, graceful transition from old to new key */
+#define P_CONTROL_V1                   4     /* control channel packet (usually TLS ciphertext) */
+#define P_ACK_V1                       5     /* acknowledgement for packets received */
+#define P_DATA_V1                      6     /* data channel packet */
+
+/* indicates key_method >= 2 */
+#define P_CONTROL_HARD_RESET_CLIENT_V2 7     /* initial key from client, forget previous state */
+#define P_CONTROL_HARD_RESET_SERVER_V2 8     /* initial key from server, forget previous state */
+
+/* define the range of legal opcodes */
+#define P_FIRST_OPCODE                 1
+#define P_LAST_OPCODE                  8
+
+/* key negotiation states */
+#define S_ERROR          -1
+#define S_UNDEF           0
+#define S_INITIAL         1	/* tls_init() was called */
+#define S_PRE_START       2	/* waiting for initial reset & acknowledgement */
+#define S_START           3	/* ready to exchange keys */
+#define S_SENT_KEY        4	/* client does S_SENT_KEY -> S_GOT_KEY */
+#define S_GOT_KEY         5	/* server does S_GOT_KEY -> S_SENT_KEY */
+#define S_ACTIVE          6	/* ready to exchange data channel packets */
+#define S_NORMAL_OP       7	/* normal operations */
+
+/*
+ * Are we ready to receive data channel packets?
+ *
+ * Also, if true, we can safely assume session has been
+ * authenticated by TLS.
+ *
+ * NOTE: Assumes S_SENT_KEY + 1 == S_GOT_KEY.
+ */
+#define DECRYPT_KEY_ENABLED(multi, ks) ((ks)->state >= (S_GOT_KEY - (multi)->opt.server))
+
+/* Should we aggregate TLS acknowledgements, and tack them onto control packets? */
+#define TLS_AGGREGATE_ACK
+
+/*
+ * If TLS_AGGREGATE_ACK, set the
+ * max number of acknowledgments that
+ * can "hitch a ride" on an outgoing
+ * non-P_ACK_V1 control packet.
+ */
+#define CONTROL_SEND_ACK_MAX 4
+
+/*
+ * Define number of buffers for send and receive in the reliability layer.
+ */
+#define TLS_RELIABLE_N_SEND_BUFFERS  4 /* also window size for reliablity layer */
+#define TLS_RELIABLE_N_REC_BUFFERS   8
+
+/*
+ * Various timeouts
+ */
+ 
+#define TLS_MULTI_REFRESH 15    /* call tls_multi_process once every n seconds */
+#define TLS_MULTI_HORIZON 2     /* call tls_multi_process frequently for n seconds after
+				   every packet sent/received action */
+
+/* The SSL/TLS worker thread will wait at most this many seconds for the interprocess
+   communication pipe to the main thread to be ready to accept writes. */
+#define TLS_MULTI_THREAD_SEND_TIMEOUT 5
+
+/* Interval that tls_multi_process should call tls_authentication_status */
+#define TLS_MULTI_AUTH_STATUS_INTERVAL 10
+
+/*
+ * Buffer sizes (also see mtu.h).
+ */
+
+/* Maximum length of the username in cert */
+#define TLS_USERNAME_LEN 64
+
+/* Legal characters in an X509 or common name */
+#define X509_NAME_CHAR_CLASS   (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_COLON|CC_SLASH|CC_EQUAL)
+#define COMMON_NAME_CHAR_CLASS (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_SLASH)
+
+/* Maximum length of OCC options string passed as part of auth handshake */
+#define TLS_OPTIONS_LEN 512
+
+/* Default field in X509 to be username */
+#define X509_USERNAME_FIELD_DEFAULT "CN"
+
+/*
+ * Range of key exchange methods
+ */
+#define KEY_METHOD_MIN 1
+#define KEY_METHOD_MAX 2
+
+/* key method taken from lower 4 bits */
+#define KEY_METHOD_MASK 0x0F
+
+/*
+ * Measure success rate of TLS handshakes, for debugging only
+ */
+/* #define MEASURE_TLS_HANDSHAKE_STATS */
+
+/*
+ * Keep track of certificate hashes at various depths
+ */
+
+/* Maximum certificate depth we will allow */
+#define MAX_CERT_DEPTH 16
+
+struct cert_hash {
+  unsigned char sha1_hash[SHA_DIGEST_LENGTH];
+};
+
+struct cert_hash_set {
+  struct cert_hash *ch[MAX_CERT_DEPTH];
+};
+
+/*
+ * Key material, used as source for PRF-based
+ * key expansion.
+ */
+
+struct key_source {
+  uint8_t pre_master[48]; /* client generated */
+  uint8_t random1[32];    /* generated by both client and server */
+  uint8_t random2[32];    /* generated by both client and server */
+};
+
+struct key_source2 {
+  struct key_source client;
+  struct key_source server;
+};
+
+/*
+ * Represents a single instantiation of a TLS negotiation and
+ * data channel key exchange.  4 keys are kept: encrypt hmac,
+ * decrypt hmac, encrypt cipher, and decrypt cipher.  The TLS
+ * control channel is used to exchange these keys.
+ * Each hard or soft reset will build
+ * a fresh key_state.  Normally an openvpn session will contain two
+ * key_state objects, one for the current TLS connection, and other
+ * for the retiring or "lame duck" key.  The lame duck key_state is
+ * used to maintain transmission continuity on the data-channel while
+ * a key renegotiation is taking place.
+ */
+struct key_state
+{
+  int state;
+  int key_id;			/* inherited from struct tls_session below */
+
+  SSL *ssl;			/* SSL object -- new obj created for each new key */
+  BIO *ssl_bio;			/* read/write plaintext from here */
+  BIO *ct_in;			/* write ciphertext to here */
+  BIO *ct_out;			/* read ciphertext from here */
+
+  time_t established;		/* when our state went S_ACTIVE */
+  time_t must_negotiate;	/* key negotiation times out if not finished before this time */
+  time_t must_die;		/* this object is destroyed at this time */
+
+  int initial_opcode;		/* our initial P_ opcode */
+  struct session_id session_id_remote;   /* peer's random session ID */
+  struct link_socket_actual remote_addr; /* peer's IP addr */
+  struct packet_id packet_id;	       /* for data channel, to prevent replay attacks */
+
+  struct key_ctx_bi key;	       /* data channel keys for encrypt/decrypt/hmac */
+
+  struct key_source2 *key_src;         /* source entropy for key expansion */
+
+  struct buffer plaintext_read_buf;
+  struct buffer plaintext_write_buf;
+  struct buffer ack_write_buf;
+
+  struct reliable *send_reliable; /* holds a copy of outgoing packets until ACK received */
+  struct reliable *rec_reliable;  /* order incoming ciphertext packets before we pass to TLS */
+  struct reliable_ack *rec_ack;	  /* buffers all packet IDs we want to ACK back to sender */
+
+  struct buffer_list *paybuf;
+
+  counter_type n_bytes;		 /* how many bytes sent/recvd since last key exchange */
+  counter_type n_packets;	 /* how many packets sent/recvd since last key exchange */
+
+  /*
+   * If bad username/password, TLS connection will come up but 'authenticated' will be false.
+   */
+  bool authenticated;
+  time_t auth_deferred_expire;
+
+#ifdef ENABLE_DEF_AUTH
+  /* If auth_deferred is true, authentication is being deferred */
+  bool auth_deferred;
+#ifdef MANAGEMENT_DEF_AUTH
+  unsigned int mda_key_id;
+  unsigned int mda_status;
+#endif
+#ifdef PLUGIN_DEF_AUTH
+  unsigned int auth_control_status;
+  time_t acf_last_mod;
+  char *auth_control_file;
+#endif
+#endif
+};
+
+/*
+ * Our const options, obtained directly or derived from
+ * command line options.
+ */
+struct tls_options
+{
+  /* our master SSL_CTX from which all SSL objects derived */
+  SSL_CTX *ssl_ctx;
+
+  /* data channel cipher, hmac, and key lengths */
+  struct key_type key_type;
+
+  /* true if we are a TLS server, client otherwise */
+  bool server;
+
+  /* if true, don't xmit until first packet from peer is received */
+  bool xmit_hold;
+
+#ifdef ENABLE_OCC
+  /* local and remote options strings
+     that must match between client and server */
+  const char *local_options;
+  const char *remote_options;
+#endif
+
+  /* from command line */
+  int key_method;
+  bool replay;
+  bool single_session;
+#ifdef ENABLE_OCC
+  bool disable_occ;
+#endif
+#ifdef ENABLE_PUSH_PEER_INFO
+  bool push_peer_info;
+#endif
+  int transition_window;
+  int handshake_window;
+  interval_t packet_timeout;
+  int renegotiate_bytes;
+  int renegotiate_packets;
+  interval_t renegotiate_seconds;
+
+  /* cert verification parms */
+  const char *verify_command;
+  const char *verify_export_cert;
+  const char *verify_x509name;
+  const char *crl_file;
+  int ns_cert_type;
+  unsigned remote_cert_ku[MAX_PARMS];
+  const char *remote_cert_eku;
+
+  /* allow openvpn config info to be
+     passed over control channel */
+  bool pass_config_info;
+
+  /* struct crypto_option flags */
+  unsigned int crypto_flags_and;
+  unsigned int crypto_flags_or;
+
+  int replay_window;                   /* --replay-window parm */
+  int replay_time;                     /* --replay-window parm */
+
+  /* packet authentication for TLS handshake */
+  struct crypto_options tls_auth;
+  struct key_ctx_bi tls_auth_key;
+
+  /* frame parameters for TLS control channel */
+  struct frame frame;
+
+  /* used for username/password authentication */
+  const char *auth_user_pass_verify_script;
+  bool auth_user_pass_verify_script_via_file;
+  const char *tmp_dir;
+
+  /* use the client-config-dir as a positive authenticator */
+  const char *client_config_dir_exclusive;
+
+  /* instance-wide environment variable set */
+  struct env_set *es;
+  const struct plugin_list *plugins;
+
+  /* configuration file boolean options */
+# define SSLF_CLIENT_CERT_NOT_REQUIRED (1<<0)
+# define SSLF_USERNAME_AS_COMMON_NAME  (1<<1)
+# define SSLF_AUTH_USER_PASS_OPTIONAL  (1<<2)
+# define SSLF_NO_NAME_REMAPPING        (1<<3)
+# define SSLF_OPT_VERIFY               (1<<4)
+  unsigned int ssl_flags;
+
+#ifdef MANAGEMENT_DEF_AUTH
+  struct man_def_auth_context *mda_context;
+#endif
+
+  /* --gremlin bits */
+  int gremlin;
+};
+
+/* index into tls_session.key */
+#define KS_PRIMARY    0		/* the primary key */
+#define KS_LAME_DUCK  1		/* the key that's going to retire soon */
+#define KS_SIZE       2
+
+/*
+ * A tls_session lives through multiple key_state life-cycles.  Soft resets
+ * will reuse a tls_session object, but hard resets or errors will require
+ * that a fresh object be built.  Normally three tls_session objects are maintained
+ * by an active openvpn session.  The first is the current, TLS authenticated
+ * session, the second is used to process connection requests from a new
+ * client that would usurp the current session if successfully authenticated,
+ * and the third is used as a repository for a "lame-duck" key in the event
+ * that the primary session resets due to error while the lame-duck key still
+ * has time left before its expiration.  Lame duck keys are used to maintain
+ * the continuity of the data channel connection while a new key is being
+ * negotiated.
+ */
+struct tls_session
+{
+  /* const options and config info */
+  const struct tls_options *opt;
+
+  /* during hard reset used to control burst retransmit */
+  bool burst;
+
+  /* authenticate control packets */
+  struct crypto_options tls_auth;
+  struct packet_id tls_auth_pid;
+
+  int initial_opcode;		/* our initial P_ opcode */
+  struct session_id session_id;	/* our random session ID */
+  int key_id;			/* increments with each soft reset (for key renegotiation) */
+
+  int limit_next;               /* used for traffic shaping on the control channel */
+
+  int verify_maxlevel;
+
+  char *common_name;
+
+  struct cert_hash_set *cert_hash_set;
+
+#ifdef ENABLE_PF
+  uint32_t common_name_hashval;
+#endif
+
+  bool verified;                /* true if peer certificate was verified against CA */
+
+  /* not-yet-authenticated incoming client */
+  struct link_socket_actual untrusted_addr;
+
+  struct key_state key[KS_SIZE];
+};
+
+/* index into tls_multi.session */
+#define TM_ACTIVE    0
+#define TM_UNTRUSTED 1
+#define TM_LAME_DUCK 2
+#define TM_SIZE      3
+
+/*
+ * The number of keys we will scan on encrypt or decrypt.  The first
+ * is the "active" key.  The second is the lame_duck or retiring key
+ * associated with the active key's session ID.  The third is a detached
+ * lame duck session that only occurs in situations where a key renegotiate
+ * failed on the active key, but a lame duck key was still valid.  By
+ * preserving the lame duck session, we can be assured of having a data
+ * channel key available even when network conditions are so bad that
+ * we can't negotiate a new key within the time allotted.
+ */
+#define KEY_SCAN_SIZE 3
+
+/*
+ * An openvpn session running with TLS enabled has one tls_multi object.
+ */
+struct tls_multi
+{
+  /* const options and config info */
+  struct tls_options opt;
+
+  /*
+   * A list of key_state objects in the order they should be
+   * scanned by data channel encrypt and decrypt routines.
+   */
+  struct key_state* key_scan[KEY_SCAN_SIZE];
+
+  /*
+   * used by tls_pre_encrypt to communicate the encrypt key
+   * to tls_post_encrypt()
+   */
+  struct key_state *save_ks;	/* temporary pointer used between pre/post routines */
+
+  /*
+   * Used to return outgoing address from
+   * tls_multi_process.
+   */
+  struct link_socket_actual to_link_addr;
+
+  /*
+   * Number of sessions negotiated thus far.
+   */
+  int n_sessions;
+
+  /*
+   * Number of errors.
+   */
+  int n_hard_errors;   /* errors due to TLS negotiation failure */
+  int n_soft_errors;   /* errors due to unrecognized or failed-to-authenticate incoming packets */
+
+  /*
+   * Our locked common name, username, and cert hashes (cannot change during the life of this tls_multi object)
+   */
+  char *locked_cn;
+  char *locked_username;
+  struct cert_hash_set *locked_cert_hash_set;
+
+#ifdef ENABLE_DEF_AUTH
+  /*
+   * An error message to send to client on AUTH_FAILED
+   */
+  char *client_reason;
+
+  /*
+   * A multi-line string of general-purpose info received from peer
+   * over control channel.
+   */
+  char *peer_info;
+
+  /* Time of last call to tls_authentication_status */
+  time_t tas_last;
+#endif
+
+  /*
+   * Our session objects.
+   */
+  struct tls_session session[TM_SIZE];
+};
+
+/*
+ * Used in --mode server mode to check tls-auth signature on initial
+ * packets received from new clients.
+ */
+struct tls_auth_standalone
+{
+  struct key_ctx_bi tls_auth_key;
+  struct crypto_options tls_auth_options;
+  struct frame frame;
+};
+
+void init_ssl_lib (void);
+void free_ssl_lib (void);
+
+/* Build master SSL_CTX object that serves for the whole of openvpn instantiation */
+SSL_CTX *init_ssl (const struct options *options);
+
+struct tls_multi *tls_multi_init (struct tls_options *tls_options);
+
+struct tls_auth_standalone *tls_auth_standalone_init (struct tls_options *tls_options,
+						      struct gc_arena *gc);
+
+void tls_auth_standalone_finalize (struct tls_auth_standalone *tas,
+				   const struct frame *frame);
+
+void tls_multi_init_finalize(struct tls_multi *multi,
+			     const struct frame *frame);
+
+void tls_multi_init_set_options(struct tls_multi* multi,
+				const char *local,
+				const char *remote);
+
+#define TLSMP_INACTIVE 0
+#define TLSMP_ACTIVE   1
+#define TLSMP_KILL     2
+int tls_multi_process (struct tls_multi *multi,
+		       struct buffer *to_link,
+		       struct link_socket_actual **to_link_addr,
+		       struct link_socket_info *to_link_socket_info,
+		       interval_t *wakeup);
+
+void tls_multi_free (struct tls_multi *multi, bool clear);
+
+bool tls_pre_decrypt (struct tls_multi *multi,
+		      const struct link_socket_actual *from,
+		      struct buffer *buf,
+		      struct crypto_options *opt);
+
+bool tls_pre_decrypt_lite (const struct tls_auth_standalone *tas,
+			   const struct link_socket_actual *from,
+			   const struct buffer *buf);
+
+void tls_pre_encrypt (struct tls_multi *multi,
+		      struct buffer *buf, struct crypto_options *opt);
+
+void tls_post_encrypt (struct tls_multi *multi, struct buffer *buf);
+
+void show_available_tls_ciphers (void);
+void get_highest_preference_tls_cipher (char *buf, int size);
+
+void pem_password_setup (const char *auth_file);
+int pem_password_callback (char *buf, int size, int rwflag, void *u);
+void auth_user_pass_setup (const char *auth_file);
+void ssl_set_auth_nocache (void);
+void ssl_purge_auth (void);
+
+
+#ifdef ENABLE_CLIENT_CR
+/*
+ * ssl_get_auth_challenge will parse the server-pushed auth-failed
+ * reason string and return a dynamically allocated
+ * auth_challenge_info struct.
+ */
+void ssl_purge_auth_challenge (void);
+void ssl_put_auth_challenge (const char *cr_str);
+#endif
+
+void tls_set_verify_command (const char *cmd);
+void tls_set_crl_verify (const char *crl);
+void tls_set_verify_x509name (const char *x509name);
+
+void tls_adjust_frame_parameters(struct frame *frame);
+
+bool tls_send_payload (struct tls_multi *multi,
+		       const uint8_t *data,
+		       int size);
+
+bool tls_rec_payload (struct tls_multi *multi,
+		      struct buffer *buf);
+
+const char *tls_common_name (const struct tls_multi* multi, const bool null);
+void tls_set_common_name (struct tls_multi *multi, const char *common_name);
+void tls_lock_common_name (struct tls_multi *multi);
+void tls_lock_cert_hash_set (struct tls_multi *multi);
+
+#define TLS_AUTHENTICATION_SUCCEEDED  0
+#define TLS_AUTHENTICATION_FAILED     1
+#define TLS_AUTHENTICATION_DEFERRED   2
+#define TLS_AUTHENTICATION_UNDEFINED  3
+int tls_authentication_status (struct tls_multi *multi, const int latency);
+void tls_deauthenticate (struct tls_multi *multi);
+
+#ifdef MANAGEMENT_DEF_AUTH
+bool tls_authenticate_key (struct tls_multi *multi, const unsigned int mda_key_id, const bool auth, const char *client_reason);
+
+static inline char *
+tls_get_peer_info(const struct tls_multi *multi)
+{
+  return multi->peer_info;
+}
+#endif
+
+/*
+ * inline functions
+ */
+
+static inline bool
+tls_initial_packet_received (const struct tls_multi *multi)
+{
+  return multi->n_sessions > 0;
+}
+
+static inline bool
+tls_test_auth_deferred_interval (const struct tls_multi *multi)
+{
+  if (multi)
+    {
+      const struct key_state *ks = &multi->session[TM_ACTIVE].key[KS_PRIMARY];
+      return now < ks->auth_deferred_expire;
+    }
+  return false;
+}
+
+static inline int
+tls_test_payload_len (const struct tls_multi *multi)
+{
+  if (multi)
+    {
+      const struct key_state *ks = &multi->session[TM_ACTIVE].key[KS_PRIMARY];
+      if (ks->state >= S_ACTIVE)
+	return BLEN (&ks->plaintext_read_buf);
+    }
+  return 0;
+}
+
+static inline void
+tls_set_single_session (struct tls_multi *multi)
+{
+  if (multi)
+    multi->opt.single_session = true;
+}
+
+static inline const char *
+tls_client_reason (struct tls_multi *multi)
+{
+#ifdef ENABLE_DEF_AUTH
+  return multi->client_reason;
+#else
+  return NULL;
+#endif
+}
+
+#ifdef ENABLE_PF
+
+static inline bool
+tls_common_name_hash (const struct tls_multi *multi, const char **cn, uint32_t *cn_hash)
+{
+  if (multi)
+    {
+      const struct tls_session *s = &multi->session[TM_ACTIVE];
+      if (s->common_name && s->common_name[0] != '\0')
+	{
+	  *cn = s->common_name;
+	  *cn_hash = s->common_name_hashval;
+	  return true;
+	}
+    }
+  return false;
+}
+
+#endif
+
+/*
+ * protocol_dump() flags
+ */
+#define PD_TLS_AUTH_HMAC_SIZE_MASK 0xFF
+#define PD_SHOW_DATA               (1<<8)
+#define PD_TLS                     (1<<9)
+#define PD_VERBOSE                 (1<<10)
+
+const char *protocol_dump (struct buffer *buffer,
+			   unsigned int flags,
+			   struct gc_arena *gc);
+
+/*
+ * debugging code
+ */
+
+#ifdef MEASURE_TLS_HANDSHAKE_STATS
+void show_tls_performance_stats(void);
+#endif
+
+/*#define EXTRACT_X509_FIELD_TEST*/
+void extract_x509_field_test (void);
+
+#endif /* USE_CRYPTO && USE_SSL */
+
+#endif