kex.h - third_party/openssh-portable - Git at Google

 /* $OpenBSD: kex.h,v 1.91 2018/07/11 18:53:29 markus Exp $ */

 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #ifndef KEX_H
 #define KEX_H

 #include "mac.h"

 #ifdef WITH_LEAKMALLOC
 #include "leakmalloc.h"
 #endif

 #ifdef WITH_OPENSSL
 # ifdef OPENSSL_HAS_ECC
 #  include <openssl/ec.h>
 # else /* OPENSSL_HAS_ECC */
 #  define EC_KEY	void
 #  define EC_GROUP	void
 #  define EC_POINT	void
 # endif /* OPENSSL_HAS_ECC */
 #else /* WITH_OPENSSL */
 # define DH		void
 # define BIGNUM		void
 # define EC_KEY		void
 # define EC_GROUP	void
 # define EC_POINT	void
 #endif /* WITH_OPENSSL */

 #define KEX_COOKIE_LEN	16

 #define	KEX_DH1				"diffie-hellman-group1-sha1"
 #define	KEX_DH14_SHA1			"diffie-hellman-group14-sha1"
 #define	KEX_DH14_SHA256			"diffie-hellman-group14-sha256"
 #define	KEX_DH16_SHA512			"diffie-hellman-group16-sha512"
 #define	KEX_DH18_SHA512			"diffie-hellman-group18-sha512"
 #define	KEX_DHGEX_SHA1			"diffie-hellman-group-exchange-sha1"
 #define	KEX_DHGEX_SHA256		"diffie-hellman-group-exchange-sha256"
 #define	KEX_ECDH_SHA2_NISTP256		"ecdh-sha2-nistp256"
 #define	KEX_ECDH_SHA2_NISTP384		"ecdh-sha2-nistp384"
 #define	KEX_ECDH_SHA2_NISTP521		"ecdh-sha2-nistp521"
 #define	KEX_CURVE25519_SHA256		"curve25519-sha256"
 #define	KEX_CURVE25519_SHA256_OLD	"curve25519-sha256@libssh.org"

 #define COMP_NONE	0
 /* pre-auth compression (COMP_ZLIB) is only supported in the client */
 #define COMP_ZLIB	1
 #define COMP_DELAYED	2

 #define CURVE25519_SIZE 32

 enum kex_init_proposals {
 	PROPOSAL_KEX_ALGS,
 	PROPOSAL_SERVER_HOST_KEY_ALGS,
 	PROPOSAL_ENC_ALGS_CTOS,
 	PROPOSAL_ENC_ALGS_STOC,
 	PROPOSAL_MAC_ALGS_CTOS,
 	PROPOSAL_MAC_ALGS_STOC,
 	PROPOSAL_COMP_ALGS_CTOS,
 	PROPOSAL_COMP_ALGS_STOC,
 	PROPOSAL_LANG_CTOS,
 	PROPOSAL_LANG_STOC,
 	PROPOSAL_MAX
 };

 enum kex_modes {
 	MODE_IN,
 	MODE_OUT,
 	MODE_MAX
 };

 enum kex_exchange {
 	KEX_DH_GRP1_SHA1,
 	KEX_DH_GRP14_SHA1,
 	KEX_DH_GRP14_SHA256,
 	KEX_DH_GRP16_SHA512,
 	KEX_DH_GRP18_SHA512,
 	KEX_DH_GEX_SHA1,
 	KEX_DH_GEX_SHA256,
 	KEX_ECDH_SHA2,
 	KEX_C25519_SHA256,
 	KEX_MAX
 };

 #define KEX_INIT_SENT	0x0001

 struct sshenc {
 	char	*name;
 	const struct sshcipher *cipher;
 	int	enabled;
 	u_int	key_len;
 	u_int	iv_len;
 	u_int	block_size;
 	u_char	*key;
 	u_char	*iv;
 };
 struct sshcomp {
 	u_int	type;
 	int	enabled;
 	char	*name;
 };
 struct newkeys {
 	struct sshenc	enc;
 	struct sshmac	mac;
 	struct sshcomp  comp;
 };

 struct ssh;

 struct kex {
 	u_char	*session_id;
 	size_t	session_id_len;
 	struct newkeys	*newkeys[MODE_MAX];
 	u_int	we_need;
 	u_int	dh_need;
 	int	server;
 	char	*name;
 	char	*hostkey_alg;
 	int	hostkey_type;
 	int	hostkey_nid;
 	u_int	kex_type;
 	char	*server_sig_algs;
 	int	ext_info_c;
 	struct sshbuf *my;
 	struct sshbuf *peer;
 	sig_atomic_t done;
 	u_int	flags;
 	int	hash_alg;
 	int	ec_nid;
 	char	*client_version_string;
 	char	*server_version_string;
 	char	*failed_choice;
 	int	(*verify_host_key)(struct sshkey *, struct ssh *);
 	struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
 	struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
 	int	(*host_key_index)(struct sshkey *, int, struct ssh *);
 	int	(*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *,
 	    const u_char *, size_t, const char *, u_int);
 	int	(*kex[KEX_MAX])(struct ssh *);
 	/* kex specific state */
 	DH	*dh;			/* DH */
 	u_int	min, max, nbits;	/* GEX */
 	EC_KEY	*ec_client_key;		/* ECDH */
 	const EC_GROUP *ec_group;	/* ECDH */
 	u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 */
 	u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
 };

 int	 kex_names_valid(const char *);
 char	*kex_alg_list(char);
 char	*kex_names_cat(const char *, const char *);
 int	 kex_assemble_names(char **, const char *, const char *);

 int	 kex_new(struct ssh *, char *[PROPOSAL_MAX], struct kex **);
 int	 kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
 void	 kex_free_newkeys(struct newkeys *);
 void	 kex_free(struct kex *);

 int	 kex_buf2prop(struct sshbuf *, int *, char ***);
 int	 kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
 void	 kex_prop_free(char **);

 int	 kex_send_kexinit(struct ssh *);
 int	 kex_input_kexinit(int, u_int32_t, struct ssh *);
 int	 kex_input_ext_info(int, u_int32_t, struct ssh *);
 int	 kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
 int	 kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *);
 int	 kex_send_newkeys(struct ssh *);
 int	 kex_start_rekex(struct ssh *);

 int	 kexdh_client(struct ssh *);
 int	 kexdh_server(struct ssh *);
 int	 kexgex_client(struct ssh *);
 int	 kexgex_server(struct ssh *);
 int	 kexecdh_client(struct ssh *);
 int	 kexecdh_server(struct ssh *);
 int	 kexc25519_client(struct ssh *);
 int	 kexc25519_server(struct ssh *);

 int	 kex_dh_hash(int, const char *, const char *,
     const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
     const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);

 int	 kexgex_hash(int, const char *, const char *,
     const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
     int, int, int,
     const BIGNUM *, const BIGNUM *, const BIGNUM *,
     const BIGNUM *, const BIGNUM *,
     u_char *, size_t *);

 int kex_ecdh_hash(int, const EC_GROUP *, const char *, const char *,
     const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
     const EC_POINT *, const EC_POINT *, const BIGNUM *, u_char *, size_t *);

 int	 kex_c25519_hash(int, const char *, const char *,
     const u_char *, size_t, const u_char *, size_t,
     const u_char *, size_t, const u_char *, const u_char *,
     const u_char *, size_t, u_char *, size_t *);

 void	kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
 	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
 	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
 int	kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
     const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
 	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
 	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));

 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
 void	dump_digest(char *, u_char *, int);
 #endif

 #if !defined(WITH_OPENSSL) || !defined(OPENSSL_HAS_ECC)
 # undef EC_KEY
 # undef EC_GROUP
 # undef EC_POINT
 #endif

 #endif
	/* $OpenBSD: kex.h,v 1.91 2018/07/11 18:53:29 markus Exp $ */

	/*
	* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	#ifndef KEX_H
	#define KEX_H

	#include "mac.h"

	#ifdef WITH_LEAKMALLOC
	#include "leakmalloc.h"
	#endif

	#ifdef WITH_OPENSSL
	# ifdef OPENSSL_HAS_ECC
	# include <openssl/ec.h>
	# else /* OPENSSL_HAS_ECC */
	# define EC_KEY void
	# define EC_GROUP void
	# define EC_POINT void
	# endif /* OPENSSL_HAS_ECC */
	#else /* WITH_OPENSSL */
	# define DH void
	# define BIGNUM void
	# define EC_KEY void
	# define EC_GROUP void
	# define EC_POINT void
	#endif /* WITH_OPENSSL */

	#define KEX_COOKIE_LEN 16

	#define KEX_DH1 "diffie-hellman-group1-sha1"
	#define KEX_DH14_SHA1 "diffie-hellman-group14-sha1"
	#define KEX_DH14_SHA256 "diffie-hellman-group14-sha256"
	#define KEX_DH16_SHA512 "diffie-hellman-group16-sha512"
	#define KEX_DH18_SHA512 "diffie-hellman-group18-sha512"
	#define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
	#define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
	#define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
	#define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
	#define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
	#define KEX_CURVE25519_SHA256 "curve25519-sha256"
	#define KEX_CURVE25519_SHA256_OLD "curve25519-sha256@libssh.org"

	#define COMP_NONE 0
	/* pre-auth compression (COMP_ZLIB) is only supported in the client */
	#define COMP_ZLIB 1
	#define COMP_DELAYED 2

	#define CURVE25519_SIZE 32

	enum kex_init_proposals {
	PROPOSAL_KEX_ALGS,
	PROPOSAL_SERVER_HOST_KEY_ALGS,
	PROPOSAL_ENC_ALGS_CTOS,
	PROPOSAL_ENC_ALGS_STOC,
	PROPOSAL_MAC_ALGS_CTOS,
	PROPOSAL_MAC_ALGS_STOC,
	PROPOSAL_COMP_ALGS_CTOS,
	PROPOSAL_COMP_ALGS_STOC,
	PROPOSAL_LANG_CTOS,
	PROPOSAL_LANG_STOC,
	PROPOSAL_MAX
	};

	enum kex_modes {
	MODE_IN,
	MODE_OUT,
	MODE_MAX
	};

	enum kex_exchange {
	KEX_DH_GRP1_SHA1,
	KEX_DH_GRP14_SHA1,
	KEX_DH_GRP14_SHA256,
	KEX_DH_GRP16_SHA512,
	KEX_DH_GRP18_SHA512,
	KEX_DH_GEX_SHA1,
	KEX_DH_GEX_SHA256,
	KEX_ECDH_SHA2,
	KEX_C25519_SHA256,
	KEX_MAX
	};

	#define KEX_INIT_SENT 0x0001

	struct sshenc {
	char *name;
	const struct sshcipher *cipher;
	int enabled;
	u_int key_len;
	u_int iv_len;
	u_int block_size;
	u_char *key;
	u_char *iv;
	};
	struct sshcomp {
	u_int type;
	int enabled;
	char *name;
	};
	struct newkeys {
	struct sshenc enc;
	struct sshmac mac;
	struct sshcomp comp;
	};

	struct ssh;

	struct kex {
	u_char *session_id;
	size_t session_id_len;
	struct newkeys *newkeys[MODE_MAX];
	u_int we_need;
	u_int dh_need;
	int server;
	char *name;
	char *hostkey_alg;
	int hostkey_type;
	int hostkey_nid;
	u_int kex_type;
	char *server_sig_algs;
	int ext_info_c;
	struct sshbuf *my;
	struct sshbuf *peer;
	sig_atomic_t done;
	u_int flags;
	int hash_alg;
	int ec_nid;
	char *client_version_string;
	char *server_version_string;
	char *failed_choice;
	int (verify_host_key)(struct sshkey , struct ssh *);
	struct sshkey (load_host_public_key)(int, int, struct ssh *);
	struct sshkey (load_host_private_key)(int, int, struct ssh *);
	int (host_key_index)(struct sshkey , int, struct ssh *);
	int (sign)(struct sshkey , struct sshkey , u_char , size_t ,
	const u_char , size_t, const char , u_int);
	int (kex[KEX_MAX])(struct ssh );
	/* kex specific state */
	DH dh; / DH */
	u_int min, max, nbits; /* GEX */
	EC_KEY ec_client_key; / ECDH */
	const EC_GROUP ec_group; / ECDH */
	u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 */
	u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
	};

	int kex_names_valid(const char *);
	char *kex_alg_list(char);
	char kex_names_cat(const char , const char *);
	int kex_assemble_names(char *, const char , const char *);

	int kex_new(struct ssh , char [PROPOSAL_MAX], struct kex **);
	int kex_setup(struct ssh , char [PROPOSAL_MAX]);
	void kex_free_newkeys(struct newkeys *);
	void kex_free(struct kex *);

	int kex_buf2prop(struct sshbuf , int , char ***);
	int kex_prop2buf(struct sshbuf , char proposal[PROPOSAL_MAX]);
	void kex_prop_free(char **);

	int kex_send_kexinit(struct ssh *);
	int kex_input_kexinit(int, u_int32_t, struct ssh *);
	int kex_input_ext_info(int, u_int32_t, struct ssh *);
	int kex_derive_keys(struct ssh , u_char , u_int, const struct sshbuf *);
	int kex_derive_keys_bn(struct ssh , u_char , u_int, const BIGNUM *);
	int kex_send_newkeys(struct ssh *);
	int kex_start_rekex(struct ssh *);

	int kexdh_client(struct ssh *);
	int kexdh_server(struct ssh *);
	int kexgex_client(struct ssh *);
	int kexgex_server(struct ssh *);
	int kexecdh_client(struct ssh *);
	int kexecdh_server(struct ssh *);
	int kexc25519_client(struct ssh *);
	int kexc25519_server(struct ssh *);

	int kex_dh_hash(int, const char , const char ,
	const u_char , size_t, const u_char , size_t, const u_char *, size_t,
	const BIGNUM , const BIGNUM , const BIGNUM , u_char , size_t *);

	int kexgex_hash(int, const char , const char ,
	const u_char , size_t, const u_char , size_t, const u_char *, size_t,
	int, int, int,
	const BIGNUM , const BIGNUM , const BIGNUM *,
	const BIGNUM , const BIGNUM ,
	u_char , size_t );

	int kex_ecdh_hash(int, const EC_GROUP , const char , const char *,
	const u_char , size_t, const u_char , size_t, const u_char *, size_t,
	const EC_POINT , const EC_POINT , const BIGNUM , u_char , size_t *);

	int kex_c25519_hash(int, const char , const char ,
	const u_char , size_t, const u_char , size_t,
	const u_char , size_t, const u_char , const u_char *,
	const u_char , size_t, u_char , size_t *);

	void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
	int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
	const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
	__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
	__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));

	#if defined(DEBUG_KEX) \|\| defined(DEBUG_KEXDH) \|\| defined(DEBUG_KEXECDH)
	void dump_digest(char , u_char , int);
	#endif

	#if !defined(WITH_OPENSSL) \|\| !defined(OPENSSL_HAS_ECC)
	# undef EC_KEY
	# undef EC_GROUP
	# undef EC_POINT
	#endif

	#endif