[gssapi-openssh.git] / openssh / cipher.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 *
 *
 * Copyright (c) 1999 Niels Provos.  All rights reserved.
 * Copyright (c) 1999, 2000 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.
 */

#include "includes.h"
RCSID("$OpenBSD: cipher.c,v 1.71 2004/07/28 09:40:29 markus Exp $");

#include "xmalloc.h"
#include "log.h"
#include "cipher.h"

#include <openssl/md5.h>

#if OPENSSL_VERSION_NUMBER < 0x00906000L
#define SSH_OLD_EVP
#define EVP_CIPHER_CTX_get_app_data(e)          ((e)->app_data)
#endif

#if OPENSSL_VERSION_NUMBER < 0x00907000L
extern const EVP_CIPHER *evp_rijndael(void);
extern void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
#endif

#if !defined(EVP_CTRL_SET_ACSS_MODE)
# if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
extern const EVP_CIPHER *evp_acss(void);
#  define EVP_acss evp_acss
#  define EVP_CTRL_SET_ACSS_MODE xxx	/* used below */
# else
#  define EVP_acss NULL /* Don't try to support ACSS on older OpenSSL */
# endif /* (OPENSSL_VERSION_NUMBER >= 0x00906000L) */
#endif /* !defined(EVP_CTRL_SET_ACSS_MODE) */

extern const EVP_CIPHER *evp_ssh1_bf(void);
extern const EVP_CIPHER *evp_ssh1_3des(void);
extern void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
extern const EVP_CIPHER *evp_aes_128_ctr(void);
extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);

struct Cipher {
	char	*name;
	int	number;		/* for ssh1 only */
	u_int	block_size;
	u_int	key_len;
	const EVP_CIPHER	*(*evptype)(void);
} ciphers[] = {
	{ "none",		SSH_CIPHER_NONE, 8, 0, EVP_enc_null },
	{ "des",		SSH_CIPHER_DES, 8, 8, EVP_des_cbc },
	{ "3des",		SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des },
	{ "blowfish",		SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf },

	{ "3des-cbc",		SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc },
	{ "blowfish-cbc",	SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc },
	{ "cast128-cbc",	SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc },
	{ "arcfour",		SSH_CIPHER_SSH2, 8, 16, EVP_rc4 },
#if OPENSSL_VERSION_NUMBER < 0x00907000L
	{ "aes128-cbc",		SSH_CIPHER_SSH2, 16, 16, evp_rijndael },
	{ "aes192-cbc",		SSH_CIPHER_SSH2, 16, 24, evp_rijndael },
	{ "aes256-cbc",		SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
	{ "rijndael-cbc@lysator.liu.se",
				SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
#else
	{ "aes128-cbc",		SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc },
	{ "aes192-cbc",		SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc },
	{ "aes256-cbc",		SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
	{ "rijndael-cbc@lysator.liu.se",
				SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
#endif
#if OPENSSL_VERSION_NUMBER >= 0x00905000L
	{ "aes128-ctr",		SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
	{ "aes192-ctr",		SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
	{ "aes256-ctr",		SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
#endif
#if defined(EVP_CTRL_SET_ACSS_MODE)
	{ "acss@openssh.org",	SSH_CIPHER_SSH2, 16, 5, EVP_acss },
#endif
	{ NULL,			SSH_CIPHER_INVALID, 0, 0, NULL }
};

/*--*/

u_int
cipher_blocksize(const Cipher *c)
{
	return (c->block_size);
}

u_int
cipher_keylen(const Cipher *c)
{
	return (c->key_len);
}

u_int
cipher_get_number(const Cipher *c)
{
	return (c->number);
}

u_int
cipher_mask_ssh1(int client)
{
	u_int mask = 0;
	mask |= 1 << SSH_CIPHER_3DES;		/* Mandatory */
	mask |= 1 << SSH_CIPHER_BLOWFISH;
	if (client) {
		mask |= 1 << SSH_CIPHER_DES;
	}
	return mask;
}

Cipher *
cipher_by_name(const char *name)
{
	Cipher *c;
	for (c = ciphers; c->name != NULL; c++)
		if (strcasecmp(c->name, name) == 0)
			return c;
	return NULL;
}

Cipher *
cipher_by_number(int id)
{
	Cipher *c;
	for (c = ciphers; c->name != NULL; c++)
		if (c->number == id)
			return c;
	return NULL;
}

#define	CIPHER_SEP	","
int
ciphers_valid(const char *names)
{
	Cipher *c;
	char *cipher_list, *cp;
	char *p;

	if (names == NULL || strcmp(names, "") == 0)
		return 0;
	cipher_list = cp = xstrdup(names);
	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
	    (p = strsep(&cp, CIPHER_SEP))) {
		c = cipher_by_name(p);
		if (c == NULL || c->number != SSH_CIPHER_SSH2) {
			debug("bad cipher %s [%s]", p, names);
			xfree(cipher_list);
			return 0;
		} else {
			debug3("cipher ok: %s [%s]", p, names);
		}
	}
	debug3("ciphers ok: [%s]", names);
	xfree(cipher_list);
	return 1;
}

/*
 * Parses the name of the cipher.  Returns the number of the corresponding
 * cipher, or -1 on error.
 */

int
cipher_number(const char *name)
{
	Cipher *c;
	if (name == NULL)
		return -1;
	c = cipher_by_name(name);
	return (c==NULL) ? -1 : c->number;
}

char *
cipher_name(int id)
{
	Cipher *c = cipher_by_number(id);
	return (c==NULL) ? "<unknown>" : c->name;
}

void
cipher_init(CipherContext *cc, Cipher *cipher,
    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
    int do_encrypt)
{
	static int dowarn = 1;
#ifdef SSH_OLD_EVP
	EVP_CIPHER *type;
#else
	const EVP_CIPHER *type;
#endif
	int klen;

	if (cipher->number == SSH_CIPHER_DES) {
		if (dowarn) {
			error("Warning: use of DES is strongly discouraged "
			    "due to cryptographic weaknesses");
			dowarn = 0;
		}
		if (keylen > 8)
			keylen = 8;
	}
	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);

	if (keylen < cipher->key_len)
		fatal("cipher_init: key length %d is insufficient for %s.",
		    keylen, cipher->name);
	if (iv != NULL && ivlen < cipher->block_size)
		fatal("cipher_init: iv length %d is insufficient for %s.",
		    ivlen, cipher->name);
	cc->cipher = cipher;

	type = (*cipher->evptype)();

	EVP_CIPHER_CTX_init(&cc->evp);
#ifdef SSH_OLD_EVP
	if (type->key_len > 0 && type->key_len != keylen) {
		debug("cipher_init: set keylen (%d -> %d)",
		    type->key_len, keylen);
		type->key_len = keylen;
	}
	EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT));
#else
	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT)) == 0)
		fatal("cipher_init: EVP_CipherInit failed for %s",
		    cipher->name);
	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	if (klen > 0 && keylen != klen) {
		debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
		if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
			fatal("cipher_init: set keylen failed (%d -> %d)",
			    klen, keylen);
	}
	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
		fatal("cipher_init: EVP_CipherInit: set key failed for %s",
		    cipher->name);
#endif
}

void
cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
{
	if (len % cc->cipher->block_size)
		fatal("cipher_encrypt: bad plaintext length %d", len);
#ifdef SSH_OLD_EVP
	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
#else
	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
		fatal("evp_crypt: EVP_Cipher failed");
#endif
}

void
cipher_cleanup(CipherContext *cc)
{
#ifdef SSH_OLD_EVP
	EVP_CIPHER_CTX_cleanup(&cc->evp);
#else
	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
		error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
#endif
}

/*
 * Selects the cipher, and keys if by computing the MD5 checksum of the
 * passphrase and using the resulting 16 bytes as the key.
 */

void
cipher_set_key_string(CipherContext *cc, Cipher *cipher,
    const char *passphrase, int do_encrypt)
{
	MD5_CTX md;
	u_char digest[16];

	MD5_Init(&md);
	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
	MD5_Final(digest, &md);

	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);

	memset(digest, 0, sizeof(digest));
	memset(&md, 0, sizeof(md));
}

/*
 * Exports an IV from the CipherContext required to export the key
 * state back from the unprivileged child to the privileged parent
 * process.
 */

int
cipher_get_keyiv_len(const CipherContext *cc)
{
	Cipher *c = cc->cipher;
	int ivlen;

	if (c->number == SSH_CIPHER_3DES)
		ivlen = 24;
	else
		ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	return (ivlen);
}

void
cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
{
	Cipher *c = cc->cipher;
	int evplen;

	switch (c->number) {
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen == 0)
			return;
		if (evplen != len)
			fatal("%s: wrong iv length %d != %d", __func__,
			    evplen, len);
#if OPENSSL_VERSION_NUMBER < 0x00907000L
		if (c->evptype == evp_rijndael)
			ssh_rijndael_iv(&cc->evp, 0, iv, len);
		else
#endif
		if (c->evptype == evp_aes_128_ctr)
			ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
		else
			memcpy(iv, cc->evp.iv, len);
		break;
	case SSH_CIPHER_3DES:
		ssh1_3des_iv(&cc->evp, 0, iv, 24);
		break;
	default:
		fatal("%s: bad cipher %d", __func__, c->number);
	}
}

void
cipher_set_keyiv(CipherContext *cc, u_char *iv)
{
	Cipher *c = cc->cipher;
	int evplen = 0;

	switch (c->number) {
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen == 0)
			return;
#if OPENSSL_VERSION_NUMBER < 0x00907000L
		if (c->evptype == evp_rijndael)
			ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
		else
#endif
		if (c->evptype == evp_aes_128_ctr)
			ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
		else
			memcpy(cc->evp.iv, iv, evplen);
		break;
	case SSH_CIPHER_3DES:
		ssh1_3des_iv(&cc->evp, 1, iv, 24);
		break;
	default:
		fatal("%s: bad cipher %d", __func__, c->number);
	}
}

#if OPENSSL_VERSION_NUMBER < 0x00907000L
#define EVP_X_STATE(evp)	&(evp).c
#define EVP_X_STATE_LEN(evp)	sizeof((evp).c)
#else
#define EVP_X_STATE(evp)	(evp).cipher_data
#define EVP_X_STATE_LEN(evp)	(evp).cipher->ctx_size
#endif

int
cipher_get_keycontext(const CipherContext *cc, u_char *dat)
{
	Cipher *c = cc->cipher;
	int plen = 0;

	if (c->evptype == EVP_rc4 || c->evptype == EVP_acss) {
		plen = EVP_X_STATE_LEN(cc->evp);
		if (dat == NULL)
			return (plen);
		memcpy(dat, EVP_X_STATE(cc->evp), plen);
	}
	return (plen);
}

void
cipher_set_keycontext(CipherContext *cc, u_char *dat)
{
	Cipher *c = cc->cipher;
	int plen;

	if (c->evptype == EVP_rc4 || c->evptype == EVP_acss) {
		plen = EVP_X_STATE_LEN(cc->evp);
		memcpy(EVP_X_STATE(cc->evp), dat, plen);
	}
}
Commit	Line	Data
3c0ef626	1	/*
	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	4	* All rights reserved
	5	*
	6	* As far as I am concerned, the code I have written for this software
	7	* can be used freely for any purpose. Any derived versions of this
	8	* software must be clearly marked as such, and if the derived work is
	9	* incompatible with the protocol description in the RFC file, it must be
	10	* called by a name other than "ssh" or "Secure Shell".
	11	*
	12	*
	13	* Copyright (c) 1999 Niels Provos. All rights reserved.
	14	* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions
	18	* are met:
	19	* 1. Redistributions of source code must retain the above copyright
	20	* notice, this list of conditions and the following disclaimer.
	21	* 2. Redistributions in binary form must reproduce the above copyright
	22	* notice, this list of conditions and the following disclaimer in the
	23	* documentation and/or other materials provided with the distribution.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	26	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	28	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	29	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	30	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	31	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	32	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	33	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	34	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	35	*/
	36
	37	#include "includes.h"
1b56ff3d	38	RCSID("$OpenBSD: cipher.c,v 1.71 2004/07/28 09:40:29 markus Exp $");
3c0ef626	39
	40	#include "xmalloc.h"
	41	#include "log.h"
	42	#include "cipher.h"
	43
	44	#include <openssl/md5.h>
1e608e42	45
2980ea68	46	#if OPENSSL_VERSION_NUMBER < 0x00906000L
	47	#define SSH_OLD_EVP
	48	#define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data)
	49	#endif
	50
ff2d7a98	51	#if OPENSSL_VERSION_NUMBER < 0x00907000L
70791e56	52	extern const EVP_CIPHER *evp_rijndael(void);
70791e56	53	extern void ssh_rijndael_iv(EVP_CIPHER_CTX , int, u_char , u_int);
ff2d7a98	54	#endif
416fd2a8	55
	56	#if !defined(EVP_CTRL_SET_ACSS_MODE)
	57	# if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
	58	extern const EVP_CIPHER *evp_acss(void);
	59	# define EVP_acss evp_acss
	60	# define EVP_CTRL_SET_ACSS_MODE xxx /* used below */
	61	# else
	62	# define EVP_acss NULL /* Don't try to support ACSS on older OpenSSL */
	63	# endif /* (OPENSSL_VERSION_NUMBER >= 0x00906000L) */
	64	#endif /* !defined(EVP_CTRL_SET_ACSS_MODE) */
	65
70791e56	66	extern const EVP_CIPHER *evp_ssh1_bf(void);
	67	extern const EVP_CIPHER *evp_ssh1_3des(void);
	68	extern void ssh1_3des_iv(EVP_CIPHER_CTX , int, u_char , int);
	69	extern const EVP_CIPHER *evp_aes_128_ctr(void);
	70	extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX , int, u_char , u_int);
1e608e42	71
	72	struct Cipher {
	73	char *name;
	74	int number; /* for ssh1 only */
	75	u_int block_size;
	76	u_int key_len;
ff2d7a98	77	const EVP_CIPHER (evptype)(void);
1e608e42	78	} ciphers[] = {
1b56ff3d	79	{ "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null },
	80	{ "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc },
	81	{ "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des },
	82	{ "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf },
	83
	84	{ "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc },
	85	{ "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc },
	86	{ "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc },
	87	{ "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 },
ff2d7a98	88	#if OPENSSL_VERSION_NUMBER < 0x00907000L
1b56ff3d	89	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael },
	90	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael },
	91	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
2980ea68	92	{ "rijndael-cbc@lysator.liu.se",
2980ea68	93	SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
ff2d7a98	94	#else
	95	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc },
	96	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc },
	97	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
	98	{ "rijndael-cbc@lysator.liu.se",
	99	SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
	100	#endif
416fd2a8	101	#if OPENSSL_VERSION_NUMBER >= 0x00905000L
1b56ff3d	102	{ "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
	103	{ "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
	104	{ "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
70791e56	105	#endif
416fd2a8	106	#if defined(EVP_CTRL_SET_ACSS_MODE)
	107	{ "acss@openssh.org", SSH_CIPHER_SSH2, 16, 5, EVP_acss },
	108	#endif
1b56ff3d	109	{ NULL, SSH_CIPHER_INVALID, 0, 0, NULL }
1e608e42	110	};
3c0ef626	111
1e608e42	112	/--/
3c0ef626	113
1e608e42	114	u_int
416fd2a8	115	cipher_blocksize(const Cipher *c)
3c0ef626	116	{
1e608e42	117	return (c->block_size);
3c0ef626	118	}
ff2d7a98	119
1e608e42	120	u_int
416fd2a8	121	cipher_keylen(const Cipher *c)
3c0ef626	122	{
1e608e42	123	return (c->key_len);
3c0ef626	124	}
ff2d7a98	125
1e608e42	126	u_int
416fd2a8	127	cipher_get_number(const Cipher *c)
3c0ef626	128	{
1e608e42	129	return (c->number);
3c0ef626	130	}
3c0ef626	131
3c0ef626	132	u_int
	133	cipher_mask_ssh1(int client)
	134	{
	135	u_int mask = 0;
1e608e42	136	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
3c0ef626	137	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	138	if (client) {
	139	mask \|= 1 << SSH_CIPHER_DES;
	140	}
	141	return mask;
	142	}
	143
	144	Cipher *
	145	cipher_by_name(const char *name)
	146	{
	147	Cipher *c;
	148	for (c = ciphers; c->name != NULL; c++)
	149	if (strcasecmp(c->name, name) == 0)
	150	return c;
	151	return NULL;
	152	}
	153
	154	Cipher *
	155	cipher_by_number(int id)
	156	{
	157	Cipher *c;
	158	for (c = ciphers; c->name != NULL; c++)
	159	if (c->number == id)
	160	return c;
	161	return NULL;
	162	}
	163
	164	#define CIPHER_SEP ","
	165	int
	166	ciphers_valid(const char *names)
	167	{
	168	Cipher *c;
1b56ff3d	169	char cipher_list, cp;
3c0ef626	170	char *p;
	171
	172	if (names == NULL \|\| strcmp(names, "") == 0)
	173	return 0;
1b56ff3d	174	cipher_list = cp = xstrdup(names);
3c0ef626	175	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1e608e42	176	(p = strsep(&cp, CIPHER_SEP))) {
3c0ef626	177	c = cipher_by_name(p);
	178	if (c == NULL \|\| c->number != SSH_CIPHER_SSH2) {
	179	debug("bad cipher %s [%s]", p, names);
1b56ff3d	180	xfree(cipher_list);
3c0ef626	181	return 0;
	182	} else {
	183	debug3("cipher ok: %s [%s]", p, names);
	184	}
	185	}
	186	debug3("ciphers ok: [%s]", names);
1b56ff3d	187	xfree(cipher_list);
3c0ef626	188	return 1;
	189	}
	190
	191	/*
	192	* Parses the name of the cipher. Returns the number of the corresponding
	193	* cipher, or -1 on error.
	194	*/
	195
	196	int
	197	cipher_number(const char *name)
	198	{
	199	Cipher *c;
	200	if (name == NULL)
	201	return -1;
	202	c = cipher_by_name(name);
	203	return (c==NULL) ? -1 : c->number;
	204	}
	205
	206	char *
	207	cipher_name(int id)
	208	{
	209	Cipher *c = cipher_by_number(id);
	210	return (c==NULL) ? "<unknown>" : c->name;
	211	}
	212
	213	void
	214	cipher_init(CipherContext cc, Cipher cipher,
1e608e42	215	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
1b56ff3d	216	int do_encrypt)
3c0ef626	217	{
1e608e42	218	static int dowarn = 1;
2980ea68	219	#ifdef SSH_OLD_EVP
	220	EVP_CIPHER *type;
	221	#else
1e608e42	222	const EVP_CIPHER *type;
2980ea68	223	#endif
1e608e42	224	int klen;
	225
	226	if (cipher->number == SSH_CIPHER_DES) {
	227	if (dowarn) {
	228	error("Warning: use of DES is strongly discouraged "
	229	"due to cryptographic weaknesses");
	230	dowarn = 0;
	231	}
	232	if (keylen > 8)
	233	keylen = 8;
	234	}
	235	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	236
3c0ef626	237	if (keylen < cipher->key_len)
	238	fatal("cipher_init: key length %d is insufficient for %s.",
	239	keylen, cipher->name);
	240	if (iv != NULL && ivlen < cipher->block_size)
	241	fatal("cipher_init: iv length %d is insufficient for %s.",
	242	ivlen, cipher->name);
	243	cc->cipher = cipher;
1e608e42	244
	245	type = (*cipher->evptype)();
	246
	247	EVP_CIPHER_CTX_init(&cc->evp);
2980ea68	248	#ifdef SSH_OLD_EVP
	249	if (type->key_len > 0 && type->key_len != keylen) {
	250	debug("cipher_init: set keylen (%d -> %d)",
	251	type->key_len, keylen);
	252	type->key_len = keylen;
	253	}
	254	EVP_CipherInit(&cc->evp, type, (u_char )key, (u_char )iv,
1b56ff3d	255	(do_encrypt == CIPHER_ENCRYPT));
2980ea68	256	#else
1e608e42	257	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
1b56ff3d	258	(do_encrypt == CIPHER_ENCRYPT)) == 0)
1e608e42	259	fatal("cipher_init: EVP_CipherInit failed for %s",
	260	cipher->name);
	261	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	262	if (klen > 0 && keylen != klen) {
1c14df9e	263	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
1e608e42	264	if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
	265	fatal("cipher_init: set keylen failed (%d -> %d)",
	266	klen, keylen);
	267	}
	268	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
	269	fatal("cipher_init: EVP_CipherInit: set key failed for %s",
	270	cipher->name);
2980ea68	271	#endif
3c0ef626	272	}
	273
	274	void
1e608e42	275	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
3c0ef626	276	{
	277	if (len % cc->cipher->block_size)
	278	fatal("cipher_encrypt: bad plaintext length %d", len);
2980ea68	279	#ifdef SSH_OLD_EVP
	280	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
	281	#else
1e608e42	282	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
1e608e42	283	fatal("evp_crypt: EVP_Cipher failed");
2980ea68	284	#endif
3c0ef626	285	}
	286
	287	void
1e608e42	288	cipher_cleanup(CipherContext *cc)
3c0ef626	289	{
2980ea68	290	#ifdef SSH_OLD_EVP
	291	EVP_CIPHER_CTX_cleanup(&cc->evp);
	292	#else
1e608e42	293	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
1e608e42	294	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
2980ea68	295	#endif
3c0ef626	296	}
	297
	298	/*
	299	* Selects the cipher, and keys if by computing the MD5 checksum of the
	300	* passphrase and using the resulting 16 bytes as the key.
	301	*/
	302
	303	void
	304	cipher_set_key_string(CipherContext cc, Cipher cipher,
1b56ff3d	305	const char *passphrase, int do_encrypt)
3c0ef626	306	{
	307	MD5_CTX md;
	308	u_char digest[16];
	309
	310	MD5_Init(&md);
	311	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
	312	MD5_Final(digest, &md);
	313
1b56ff3d	314	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);
3c0ef626	315
	316	memset(digest, 0, sizeof(digest));
	317	memset(&md, 0, sizeof(md));
	318	}
1e608e42	319
1e608e42	320	/*
	321	* Exports an IV from the CipherContext required to export the key
	322	* state back from the unprivileged child to the privileged parent
	323	* process.
	324	*/
	325
	326	int
416fd2a8	327	cipher_get_keyiv_len(const CipherContext *cc)
1e608e42	328	{
	329	Cipher *c = cc->cipher;
	330	int ivlen;
	331
	332	if (c->number == SSH_CIPHER_3DES)
	333	ivlen = 24;
	334	else
	335	ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	336	return (ivlen);
	337	}
	338
	339	void
	340	cipher_get_keyiv(CipherContext cc, u_char iv, u_int len)
	341	{
	342	Cipher *c = cc->cipher;
1e608e42	343	int evplen;
	344
	345	switch (c->number) {
	346	case SSH_CIPHER_SSH2:
	347	case SSH_CIPHER_DES:
	348	case SSH_CIPHER_BLOWFISH:
	349	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	350	if (evplen == 0)
	351	return;
	352	if (evplen != len)
ff2d7a98	353	fatal("%s: wrong iv length %d != %d", __func__,
1e608e42	354	evplen, len);
ff2d7a98	355	#if OPENSSL_VERSION_NUMBER < 0x00907000L
70791e56	356	if (c->evptype == evp_rijndael)
	357	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	358	else
ff2d7a98	359	#endif
70791e56	360	if (c->evptype == evp_aes_128_ctr)
	361	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	362	else
	363	memcpy(iv, cc->evp.iv, len);
	364	break;
	365	case SSH_CIPHER_3DES:
	366	ssh1_3des_iv(&cc->evp, 0, iv, 24);
1e608e42	367	break;
1e608e42	368	default:
ff2d7a98	369	fatal("%s: bad cipher %d", __func__, c->number);
1e608e42	370	}
1e608e42	371	}
	372
	373	void
	374	cipher_set_keyiv(CipherContext cc, u_char iv)
	375	{
	376	Cipher *c = cc->cipher;
1e608e42	377	int evplen = 0;
	378
	379	switch (c->number) {
	380	case SSH_CIPHER_SSH2:
	381	case SSH_CIPHER_DES:
	382	case SSH_CIPHER_BLOWFISH:
	383	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	384	if (evplen == 0)
	385	return;
ff2d7a98	386	#if OPENSSL_VERSION_NUMBER < 0x00907000L
70791e56	387	if (c->evptype == evp_rijndael)
	388	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	389	else
ff2d7a98	390	#endif
70791e56	391	if (c->evptype == evp_aes_128_ctr)
	392	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	393	else
	394	memcpy(cc->evp.iv, iv, evplen);
	395	break;
	396	case SSH_CIPHER_3DES:
	397	ssh1_3des_iv(&cc->evp, 1, iv, 24);
1e608e42	398	break;
1e608e42	399	default:
ff2d7a98	400	fatal("%s: bad cipher %d", __func__, c->number);
1e608e42	401	}
1e608e42	402	}
	403
	404	#if OPENSSL_VERSION_NUMBER < 0x00907000L
	405	#define EVP_X_STATE(evp) &(evp).c
	406	#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
	407	#else
	408	#define EVP_X_STATE(evp) (evp).cipher_data
	409	#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
	410	#endif
	411
	412	int
416fd2a8	413	cipher_get_keycontext(const CipherContext cc, u_char dat)
1e608e42	414	{
1e608e42	415	Cipher *c = cc->cipher;
ff2d7a98	416	int plen = 0;
1e608e42	417
416fd2a8	418	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
ff2d7a98	419	plen = EVP_X_STATE_LEN(cc->evp);
1e608e42	420	if (dat == NULL)
ff2d7a98	421	return (plen);
ff2d7a98	422	memcpy(dat, EVP_X_STATE(cc->evp), plen);
1e608e42	423	}
1e608e42	424	return (plen);
	425	}
	426
	427	void
	428	cipher_set_keycontext(CipherContext cc, u_char dat)
	429	{
	430	Cipher *c = cc->cipher;
	431	int plen;
	432
416fd2a8	433	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
1e608e42	434	plen = EVP_X_STATE_LEN(cc->evp);
	435	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	436	}
	437	}