[openssh.git] / 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 1.69 2004/06/21 17:36:31 avsm 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_ILLEGAL, 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,
	    (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
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
6ae2364d	5	*
bcbf86ec	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.
a96070d4	14	* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
bcbf86ec	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.
6ae2364d	24	*
bcbf86ec	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.
5260325f	35	*/
8efc0c15	36
8efc0c15	37	#include "includes.h"
ca75d7de	38	RCSID("$OpenBSD: cipher.c,v 1.69 2004/06/21 17:36:31 avsm Exp $");
8efc0c15	39
a8be9f80	40	#include "xmalloc.h"
42f11eb2	41	#include "log.h"
42f11eb2	42	#include "cipher.h"
8efc0c15	43
8efc0c15	44	#include <openssl/md5.h>
70fc1609	45
a068d86f	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
135247df	51	#if OPENSSL_VERSION_NUMBER < 0x00907000L
3b6e3da9	52	extern const EVP_CIPHER *evp_rijndael(void);
3b6e3da9	53	extern void ssh_rijndael_iv(EVP_CIPHER_CTX , int, u_char , u_int);
135247df	54	#endif
268c23e9	55
268c23e9	56	#if !defined(EVP_CTRL_SET_ACSS_MODE)
c7b91244	57	# if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
268c23e9	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
3b6e3da9	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);
25b66522	69	extern const EVP_CIPHER *evp_aes_128_ctr(void);
25b66522	70	extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX , int, u_char , u_int);
8efc0c15	71
3ee832e5	72	struct Cipher {
	73	char *name;
	74	int number; /* for ssh1 only */
	75	u_int block_size;
	76	u_int key_len;
7b5edc2b	77	const EVP_CIPHER (evptype)(void);
70fc1609	78	} ciphers[] = {
	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 },
135247df	88	#if OPENSSL_VERSION_NUMBER < 0x00907000L
70fc1609	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 },
bf03f2da	92	{ "rijndael-cbc@lysator.liu.se",
bf03f2da	93	SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
135247df	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
1c4d41b9	101	#if OPENSSL_VERSION_NUMBER >= 0x00905000L
25b66522	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 },
0a23d79f	105	#endif
268c23e9	106	#if defined(EVP_CTRL_SET_ACSS_MODE)
8b557a74	107	{ "acss@openssh.org", SSH_CIPHER_SSH2, 16, 5, EVP_acss },
268c23e9	108	#endif
70fc1609	109	{ NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL }
94ec8c6b	110	};
	111
	112	/--/
	113
762715ce	114	u_int
b6c7b7b7	115	cipher_blocksize(const Cipher *c)
3ee832e5	116	{
	117	return (c->block_size);
	118	}
3ddc795d	119
762715ce	120	u_int
b6c7b7b7	121	cipher_keylen(const Cipher *c)
3ee832e5	122	{
	123	return (c->key_len);
	124	}
3ddc795d	125
762715ce	126	u_int
b6c7b7b7	127	cipher_get_number(const Cipher *c)
bf8269a9	128	{
	129	return (c->number);
	130	}
3ee832e5	131
1e3b8b07	132	u_int
94ec8c6b	133	cipher_mask_ssh1(int client)
8ce64345	134	{
1e3b8b07	135	u_int mask = 0;
184eed6a	136	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
94ec8c6b	137	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	138	if (client) {
	139	mask \|= 1 << SSH_CIPHER_DES;
	140	}
5260325f	141	return mask;
8efc0c15	142	}
94ec8c6b	143
	144	Cipher *
	145	cipher_by_name(const char *name)
8ce64345	146	{
94ec8c6b	147	Cipher *c;
	148	for (c = ciphers; c->name != NULL; c++)
	149	if (strcasecmp(c->name, name) == 0)
	150	return c;
	151	return NULL;
8ce64345	152	}
8efc0c15	153
94ec8c6b	154	Cipher *
94ec8c6b	155	cipher_by_number(int id)
8efc0c15	156	{
94ec8c6b	157	Cipher *c;
	158	for (c = ciphers; c->name != NULL; c++)
	159	if (c->number == id)
	160	return c;
	161	return NULL;
8efc0c15	162	}
8efc0c15	163
a8be9f80	164	#define CIPHER_SEP ","
	165	int
	166	ciphers_valid(const char *names)
	167	{
94ec8c6b	168	Cipher *c;
ca75d7de	169	char cipher_list, cp;
a8be9f80	170	char *p;
a8be9f80	171
71276795	172	if (names == NULL \|\| strcmp(names, "") == 0)
a8be9f80	173	return 0;
ca75d7de	174	cipher_list = cp = xstrdup(names);
94ec8c6b	175	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
184eed6a	176	(p = strsep(&cp, CIPHER_SEP))) {
94ec8c6b	177	c = cipher_by_name(p);
	178	if (c == NULL \|\| c->number != SSH_CIPHER_SSH2) {
	179	debug("bad cipher %s [%s]", p, names);
ca75d7de	180	xfree(cipher_list);
a8be9f80	181	return 0;
94ec8c6b	182	} else {
33de75a3	183	debug3("cipher ok: %s [%s]", p, names);
a8be9f80	184	}
a8be9f80	185	}
33de75a3	186	debug3("ciphers ok: [%s]", names);
ca75d7de	187	xfree(cipher_list);
a8be9f80	188	return 1;
	189	}
	190
aa3378df	191	/*
	192	* Parses the name of the cipher. Returns the number of the corresponding
	193	* cipher, or -1 on error.
	194	*/
8efc0c15	195
	196	int
	197	cipher_number(const char *name)
	198	{
94ec8c6b	199	Cipher *c;
71276795	200	if (name == NULL)
71276795	201	return -1;
94ec8c6b	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
70fc1609	214	cipher_init(CipherContext cc, Cipher cipher,
70fc1609	215	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
ca75d7de	216	int do_encrypt)
94ec8c6b	217	{
70fc1609	218	static int dowarn = 1;
a068d86f	219	#ifdef SSH_OLD_EVP
	220	EVP_CIPHER *type;
	221	#else
70fc1609	222	const EVP_CIPHER *type;
a068d86f	223	#endif
70fc1609	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
94ec8c6b	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;
70fc1609	244
	245	type = (*cipher->evptype)();
	246
	247	EVP_CIPHER_CTX_init(&cc->evp);
a068d86f	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,
	255	(encrypt == CIPHER_ENCRYPT));
	256	#else
70fc1609	257	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
ca75d7de	258	(do_encrypt == CIPHER_ENCRYPT)) == 0)
70fc1609	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) {
a77673cc	263	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
70fc1609	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);
a068d86f	271	#endif
94ec8c6b	272	}
	273
	274	void
3ee832e5	275	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
94ec8c6b	276	{
	277	if (len % cc->cipher->block_size)
	278	fatal("cipher_encrypt: bad plaintext length %d", len);
a068d86f	279	#ifdef SSH_OLD_EVP
	280	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
	281	#else
70fc1609	282	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
70fc1609	283	fatal("evp_crypt: EVP_Cipher failed");
a068d86f	284	#endif
94ec8c6b	285	}
	286
	287	void
3ee832e5	288	cipher_cleanup(CipherContext *cc)
94ec8c6b	289	{
a068d86f	290	#ifdef SSH_OLD_EVP
	291	EVP_CIPHER_CTX_cleanup(&cc->evp);
	292	#else
70fc1609	293	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
70fc1609	294	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
a068d86f	295	#endif
8efc0c15	296	}
8efc0c15	297
aa3378df	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	*/
8efc0c15	302
6ae2364d	303	void
94ec8c6b	304	cipher_set_key_string(CipherContext cc, Cipher cipher,
ca75d7de	305	const char *passphrase, int do_encrypt)
8efc0c15	306	{
5260325f	307	MD5_CTX md;
1e3b8b07	308	u_char digest[16];
5260325f	309
5260325f	310	MD5_Init(&md);
94ec8c6b	311	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
5260325f	312	MD5_Final(digest, &md);
5260325f	313
ca75d7de	314	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);
5260325f	315
	316	memset(digest, 0, sizeof(digest));
	317	memset(&md, 0, sizeof(md));
8efc0c15	318	}
70fc1609	319
762715ce	320	/*
bf8269a9	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
b6c7b7b7	327	cipher_get_keyiv_len(const CipherContext *cc)
bf8269a9	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;
bf8269a9	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)
1588c277	353	fatal("%s: wrong iv length %d != %d", __func__,
bf8269a9	354	evplen, len);
135247df	355	#if OPENSSL_VERSION_NUMBER < 0x00907000L
18ae3c67	356	if (c->evptype == evp_rijndael)
	357	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	358	else
135247df	359	#endif
25b66522	360	if (c->evptype == evp_aes_128_ctr)
	361	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	362	else
18ae3c67	363	memcpy(iv, cc->evp.iv, len);
	364	break;
	365	case SSH_CIPHER_3DES:
	366	ssh1_3des_iv(&cc->evp, 0, iv, 24);
bf8269a9	367	break;
bf8269a9	368	default:
1588c277	369	fatal("%s: bad cipher %d", __func__, c->number);
bf8269a9	370	}
bf8269a9	371	}
	372
	373	void
	374	cipher_set_keyiv(CipherContext cc, u_char iv)
	375	{
	376	Cipher *c = cc->cipher;
bf8269a9	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;
135247df	386	#if OPENSSL_VERSION_NUMBER < 0x00907000L
18ae3c67	387	if (c->evptype == evp_rijndael)
	388	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	389	else
135247df	390	#endif
25b66522	391	if (c->evptype == evp_aes_128_ctr)
	392	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	393	else
18ae3c67	394	memcpy(cc->evp.iv, iv, evplen);
	395	break;
	396	case SSH_CIPHER_3DES:
	397	ssh1_3des_iv(&cc->evp, 1, iv, 24);
bf8269a9	398	break;
bf8269a9	399	default:
1588c277	400	fatal("%s: bad cipher %d", __func__, c->number);
bf8269a9	401	}
bf8269a9	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
b6c7b7b7	413	cipher_get_keycontext(const CipherContext cc, u_char dat)
bf8269a9	414	{
bf8269a9	415	Cipher *c = cc->cipher;
9459414c	416	int plen = 0;
bf8269a9	417
268c23e9	418	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
9459414c	419	plen = EVP_X_STATE_LEN(cc->evp);
bf8269a9	420	if (dat == NULL)
9459414c	421	return (plen);
9459414c	422	memcpy(dat, EVP_X_STATE(cc->evp), plen);
bf8269a9	423	}
bf8269a9	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
268c23e9	433	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
bf8269a9	434	plen = EVP_X_STATE_LEN(cc->evp);
	435	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	436	}
70fc1609	437	}