[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 1.65 2003/05/17 04:27:52 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
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 >= 0x00906000L
	{ "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

	{ NULL,			SSH_CIPHER_ILLEGAL, 0, 0, NULL }
};

/*--*/

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

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

u_int
cipher_get_number(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 *ciphers, *cp;
	char *p;

	if (names == NULL || strcmp(names, "") == 0)
		return 0;
	ciphers = 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(ciphers);
			return 0;
		} else {
			debug3("cipher ok: %s [%s]", p, names);
		}
	}
	debug3("ciphers ok: [%s]", names);
	xfree(ciphers);
	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 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,
	    (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 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, 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(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(CipherContext *cc, u_char *dat)
{
	Cipher *c = cc->cipher;
	int plen = 0;

	if (c->evptype == EVP_rc4) {
		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) {
		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"
25b66522	38	RCSID("$OpenBSD: cipher.c,v 1.65 2003/05/17 04:27:52 markus 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
3b6e3da9	55	extern const EVP_CIPHER *evp_ssh1_bf(void);
	56	extern const EVP_CIPHER *evp_ssh1_3des(void);
	57	extern void ssh1_3des_iv(EVP_CIPHER_CTX , int, u_char , int);
25b66522	58	extern const EVP_CIPHER *evp_aes_128_ctr(void);
25b66522	59	extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX , int, u_char , u_int);
8efc0c15	60
3ee832e5	61	struct Cipher {
	62	char *name;
	63	int number; /* for ssh1 only */
	64	u_int block_size;
	65	u_int key_len;
7b5edc2b	66	const EVP_CIPHER (evptype)(void);
70fc1609	67	} ciphers[] = {
	68	{ "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null },
	69	{ "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc },
	70	{ "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des },
	71	{ "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf },
	72
	73	{ "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc },
	74	{ "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc },
	75	{ "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc },
	76	{ "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 },
135247df	77	#if OPENSSL_VERSION_NUMBER < 0x00907000L
70fc1609	78	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael },
	79	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael },
	80	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
bf03f2da	81	{ "rijndael-cbc@lysator.liu.se",
bf03f2da	82	SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
135247df	83	#else
	84	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc },
	85	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc },
	86	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
	87	{ "rijndael-cbc@lysator.liu.se",
	88	SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
	89	#endif
0a23d79f	90	#if OPENSSL_VERSION_NUMBER >= 0x00906000L
25b66522	91	{ "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
	92	{ "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
	93	{ "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
0a23d79f	94	#endif
70fc1609	95
70fc1609	96	{ NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL }
94ec8c6b	97	};
	98
	99	/--/
	100
762715ce	101	u_int
3ee832e5	102	cipher_blocksize(Cipher *c)
	103	{
	104	return (c->block_size);
	105	}
3ddc795d	106
762715ce	107	u_int
3ee832e5	108	cipher_keylen(Cipher *c)
	109	{
	110	return (c->key_len);
	111	}
3ddc795d	112
762715ce	113	u_int
bf8269a9	114	cipher_get_number(Cipher *c)
	115	{
	116	return (c->number);
	117	}
3ee832e5	118
1e3b8b07	119	u_int
94ec8c6b	120	cipher_mask_ssh1(int client)
8ce64345	121	{
1e3b8b07	122	u_int mask = 0;
184eed6a	123	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
94ec8c6b	124	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	125	if (client) {
	126	mask \|= 1 << SSH_CIPHER_DES;
	127	}
5260325f	128	return mask;
8efc0c15	129	}
94ec8c6b	130
	131	Cipher *
	132	cipher_by_name(const char *name)
8ce64345	133	{
94ec8c6b	134	Cipher *c;
	135	for (c = ciphers; c->name != NULL; c++)
	136	if (strcasecmp(c->name, name) == 0)
	137	return c;
	138	return NULL;
8ce64345	139	}
8efc0c15	140
94ec8c6b	141	Cipher *
94ec8c6b	142	cipher_by_number(int id)
8efc0c15	143	{
94ec8c6b	144	Cipher *c;
	145	for (c = ciphers; c->name != NULL; c++)
	146	if (c->number == id)
	147	return c;
	148	return NULL;
8efc0c15	149	}
8efc0c15	150
a8be9f80	151	#define CIPHER_SEP ","
	152	int
	153	ciphers_valid(const char *names)
	154	{
94ec8c6b	155	Cipher *c;
089fbbd2	156	char ciphers, cp;
a8be9f80	157	char *p;
a8be9f80	158
71276795	159	if (names == NULL \|\| strcmp(names, "") == 0)
a8be9f80	160	return 0;
089fbbd2	161	ciphers = cp = xstrdup(names);
94ec8c6b	162	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
184eed6a	163	(p = strsep(&cp, CIPHER_SEP))) {
94ec8c6b	164	c = cipher_by_name(p);
	165	if (c == NULL \|\| c->number != SSH_CIPHER_SSH2) {
	166	debug("bad cipher %s [%s]", p, names);
a8be9f80	167	xfree(ciphers);
a8be9f80	168	return 0;
94ec8c6b	169	} else {
33de75a3	170	debug3("cipher ok: %s [%s]", p, names);
a8be9f80	171	}
a8be9f80	172	}
33de75a3	173	debug3("ciphers ok: [%s]", names);
a8be9f80	174	xfree(ciphers);
	175	return 1;
	176	}
	177
aa3378df	178	/*
	179	* Parses the name of the cipher. Returns the number of the corresponding
	180	* cipher, or -1 on error.
	181	*/
8efc0c15	182
	183	int
	184	cipher_number(const char *name)
	185	{
94ec8c6b	186	Cipher *c;
71276795	187	if (name == NULL)
71276795	188	return -1;
94ec8c6b	189	c = cipher_by_name(name);
	190	return (c==NULL) ? -1 : c->number;
	191	}
	192
	193	char *
	194	cipher_name(int id)
	195	{
	196	Cipher *c = cipher_by_number(id);
	197	return (c==NULL) ? "<unknown>" : c->name;
	198	}
	199
	200	void
70fc1609	201	cipher_init(CipherContext cc, Cipher cipher,
	202	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
	203	int encrypt)
94ec8c6b	204	{
70fc1609	205	static int dowarn = 1;
a068d86f	206	#ifdef SSH_OLD_EVP
	207	EVP_CIPHER *type;
	208	#else
70fc1609	209	const EVP_CIPHER *type;
a068d86f	210	#endif
70fc1609	211	int klen;
	212
	213	if (cipher->number == SSH_CIPHER_DES) {
	214	if (dowarn) {
	215	error("Warning: use of DES is strongly discouraged "
	216	"due to cryptographic weaknesses");
	217	dowarn = 0;
	218	}
	219	if (keylen > 8)
	220	keylen = 8;
	221	}
	222	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	223
94ec8c6b	224	if (keylen < cipher->key_len)
	225	fatal("cipher_init: key length %d is insufficient for %s.",
	226	keylen, cipher->name);
	227	if (iv != NULL && ivlen < cipher->block_size)
	228	fatal("cipher_init: iv length %d is insufficient for %s.",
	229	ivlen, cipher->name);
	230	cc->cipher = cipher;
70fc1609	231
	232	type = (*cipher->evptype)();
	233
	234	EVP_CIPHER_CTX_init(&cc->evp);
a068d86f	235	#ifdef SSH_OLD_EVP
	236	if (type->key_len > 0 && type->key_len != keylen) {
	237	debug("cipher_init: set keylen (%d -> %d)",
	238	type->key_len, keylen);
	239	type->key_len = keylen;
	240	}
	241	EVP_CipherInit(&cc->evp, type, (u_char )key, (u_char )iv,
	242	(encrypt == CIPHER_ENCRYPT));
	243	#else
70fc1609	244	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
	245	(encrypt == CIPHER_ENCRYPT)) == 0)
	246	fatal("cipher_init: EVP_CipherInit failed for %s",
	247	cipher->name);
	248	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	249	if (klen > 0 && keylen != klen) {
a77673cc	250	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
70fc1609	251	if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
	252	fatal("cipher_init: set keylen failed (%d -> %d)",
	253	klen, keylen);
	254	}
	255	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
	256	fatal("cipher_init: EVP_CipherInit: set key failed for %s",
	257	cipher->name);
a068d86f	258	#endif
94ec8c6b	259	}
	260
	261	void
3ee832e5	262	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
94ec8c6b	263	{
	264	if (len % cc->cipher->block_size)
	265	fatal("cipher_encrypt: bad plaintext length %d", len);
a068d86f	266	#ifdef SSH_OLD_EVP
	267	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
	268	#else
70fc1609	269	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
70fc1609	270	fatal("evp_crypt: EVP_Cipher failed");
a068d86f	271	#endif
94ec8c6b	272	}
	273
	274	void
3ee832e5	275	cipher_cleanup(CipherContext *cc)
94ec8c6b	276	{
a068d86f	277	#ifdef SSH_OLD_EVP
	278	EVP_CIPHER_CTX_cleanup(&cc->evp);
	279	#else
70fc1609	280	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
70fc1609	281	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
a068d86f	282	#endif
8efc0c15	283	}
8efc0c15	284
aa3378df	285	/*
	286	* Selects the cipher, and keys if by computing the MD5 checksum of the
	287	* passphrase and using the resulting 16 bytes as the key.
	288	*/
8efc0c15	289
6ae2364d	290	void
94ec8c6b	291	cipher_set_key_string(CipherContext cc, Cipher cipher,
3ee832e5	292	const char *passphrase, int encrypt)
8efc0c15	293	{
5260325f	294	MD5_CTX md;
1e3b8b07	295	u_char digest[16];
5260325f	296
5260325f	297	MD5_Init(&md);
94ec8c6b	298	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
5260325f	299	MD5_Final(digest, &md);
5260325f	300
3ee832e5	301	cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt);
5260325f	302
	303	memset(digest, 0, sizeof(digest));
	304	memset(&md, 0, sizeof(md));
8efc0c15	305	}
70fc1609	306
762715ce	307	/*
bf8269a9	308	* Exports an IV from the CipherContext required to export the key
	309	* state back from the unprivileged child to the privileged parent
	310	* process.
	311	*/
	312
	313	int
	314	cipher_get_keyiv_len(CipherContext *cc)
	315	{
	316	Cipher *c = cc->cipher;
	317	int ivlen;
	318
	319	if (c->number == SSH_CIPHER_3DES)
	320	ivlen = 24;
	321	else
	322	ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	323	return (ivlen);
	324	}
	325
	326	void
	327	cipher_get_keyiv(CipherContext cc, u_char iv, u_int len)
	328	{
	329	Cipher *c = cc->cipher;
bf8269a9	330	int evplen;
	331
	332	switch (c->number) {
	333	case SSH_CIPHER_SSH2:
	334	case SSH_CIPHER_DES:
	335	case SSH_CIPHER_BLOWFISH:
	336	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	337	if (evplen == 0)
	338	return;
	339	if (evplen != len)
1588c277	340	fatal("%s: wrong iv length %d != %d", __func__,
bf8269a9	341	evplen, len);
135247df	342	#if OPENSSL_VERSION_NUMBER < 0x00907000L
18ae3c67	343	if (c->evptype == evp_rijndael)
	344	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	345	else
135247df	346	#endif
25b66522	347	if (c->evptype == evp_aes_128_ctr)
	348	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	349	else
18ae3c67	350	memcpy(iv, cc->evp.iv, len);
	351	break;
	352	case SSH_CIPHER_3DES:
	353	ssh1_3des_iv(&cc->evp, 0, iv, 24);
bf8269a9	354	break;
bf8269a9	355	default:
1588c277	356	fatal("%s: bad cipher %d", __func__, c->number);
bf8269a9	357	}
bf8269a9	358	}
	359
	360	void
	361	cipher_set_keyiv(CipherContext cc, u_char iv)
	362	{
	363	Cipher *c = cc->cipher;
bf8269a9	364	int evplen = 0;
	365
	366	switch (c->number) {
	367	case SSH_CIPHER_SSH2:
	368	case SSH_CIPHER_DES:
	369	case SSH_CIPHER_BLOWFISH:
	370	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	371	if (evplen == 0)
	372	return;
135247df	373	#if OPENSSL_VERSION_NUMBER < 0x00907000L
18ae3c67	374	if (c->evptype == evp_rijndael)
	375	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	376	else
135247df	377	#endif
25b66522	378	if (c->evptype == evp_aes_128_ctr)
	379	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	380	else
18ae3c67	381	memcpy(cc->evp.iv, iv, evplen);
	382	break;
	383	case SSH_CIPHER_3DES:
	384	ssh1_3des_iv(&cc->evp, 1, iv, 24);
bf8269a9	385	break;
bf8269a9	386	default:
1588c277	387	fatal("%s: bad cipher %d", __func__, c->number);
bf8269a9	388	}
bf8269a9	389	}
	390
	391	#if OPENSSL_VERSION_NUMBER < 0x00907000L
	392	#define EVP_X_STATE(evp) &(evp).c
	393	#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
	394	#else
	395	#define EVP_X_STATE(evp) (evp).cipher_data
	396	#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
	397	#endif
	398
	399	int
	400	cipher_get_keycontext(CipherContext cc, u_char dat)
	401	{
	402	Cipher *c = cc->cipher;
9459414c	403	int plen = 0;
bf8269a9	404
9459414c	405	if (c->evptype == EVP_rc4) {
9459414c	406	plen = EVP_X_STATE_LEN(cc->evp);
bf8269a9	407	if (dat == NULL)
9459414c	408	return (plen);
9459414c	409	memcpy(dat, EVP_X_STATE(cc->evp), plen);
bf8269a9	410	}
bf8269a9	411	return (plen);
	412	}
	413
	414	void
	415	cipher_set_keycontext(CipherContext cc, u_char dat)
	416	{
	417	Cipher *c = cc->cipher;
	418	int plen;
	419
9459414c	420	if (c->evptype == EVP_rc4) {
bf8269a9	421	plen = EVP_X_STATE_LEN(cc->evp);
	422	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	423	}
70fc1609	424	}