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

/* $OpenBSD: cipher.c,v 1.82 2009/01/26 09:58:15 markus Exp $ */
/*
 * 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"

#include <sys/types.h>

#include <openssl/md5.h>

#include <string.h>
#include <stdarg.h>

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

/* compatibility with old or broken OpenSSL versions */
#include "openbsd-compat/openssl-compat.h"

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 const EVP_CIPHER *evp_aes_ctr_mt(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;
	u_int	discard_len;
	u_int	cbc_mode;
	const EVP_CIPHER	*(*evptype)(void);
} ciphers[] = {
	{ "none",		SSH_CIPHER_NONE, 8, 0, 0, 0, EVP_enc_null },
	{ "des",		SSH_CIPHER_DES, 8, 8, 0, 1, EVP_des_cbc },
	{ "3des",		SSH_CIPHER_3DES, 8, 16, 0, 1, evp_ssh1_3des },
	{ "blowfish",		SSH_CIPHER_BLOWFISH, 8, 32, 0, 1, evp_ssh1_bf },

	{ "3des-cbc",		SSH_CIPHER_SSH2, 8, 24, 0, 1, EVP_des_ede3_cbc },
	{ "blowfish-cbc",	SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_bf_cbc },
	{ "cast128-cbc",	SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_cast5_cbc },
	{ "arcfour",		SSH_CIPHER_SSH2, 8, 16, 0, 0, EVP_rc4 },
	{ "arcfour128",		SSH_CIPHER_SSH2, 8, 16, 1536, 0, EVP_rc4 },
	{ "arcfour256",		SSH_CIPHER_SSH2, 8, 32, 1536, 0, EVP_rc4 },
	{ "aes128-cbc",		SSH_CIPHER_SSH2, 16, 16, 0, 1, EVP_aes_128_cbc },
	{ "aes192-cbc",		SSH_CIPHER_SSH2, 16, 24, 0, 1, EVP_aes_192_cbc },
	{ "aes256-cbc",		SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
	{ "rijndael-cbc@lysator.liu.se",
				SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
	{ "aes128-ctr",		SSH_CIPHER_SSH2, 16, 16, 0, 0, evp_aes_ctr_mt },
	{ "aes192-ctr",		SSH_CIPHER_SSH2, 16, 24, 0, 0, evp_aes_ctr_mt },
	{ "aes256-ctr",		SSH_CIPHER_SSH2, 16, 32, 0, 0, evp_aes_ctr_mt },
#ifdef USE_CIPHER_ACSS
	{ "acss@openssh.org",	SSH_CIPHER_SSH2, 16, 5, 0, 0, EVP_acss },
#endif
	{ NULL,			SSH_CIPHER_INVALID, 0, 0, 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_is_cbc(const Cipher *c)
{
	return (c->cbc_mode);
}

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 (strcmp(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 && 
c->number != SSH_CIPHER_NONE)) {
			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;
	for (c = ciphers; c->name != NULL; c++)
		if (strcasecmp(c->name, name) == 0)
			return c->number;
	return -1;
}

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;
	int klen;
#endif
	u_char *junk, *discard;

	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 != (u_int)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

	if (cipher->discard_len > 0) {
		junk = xmalloc(cipher->discard_len);
		discard = xmalloc(cipher->discard_len);
		if (EVP_Cipher(&cc->evp, discard, junk,
		    cipher->discard_len) == 0)
			fatal("evp_crypt: EVP_Cipher failed during discard");
		memset(discard, 0, cipher->discard_len);
		xfree(junk);
		xfree(discard);
	}
}

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);
	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
		fatal("evp_crypt: EVP_Cipher failed");
}

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

/*
 * 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_NONE:
	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 ((u_int)evplen != len)
			fatal("%s: wrong iv length %d != %d", __func__,
			    evplen, len);
#ifdef USE_BUILTIN_RIJNDAEL
		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_NONE:
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen == 0)
			return;
#ifdef USE_BUILTIN_RIJNDAEL
		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
91d9cdd3	1	/* $OpenBSD: cipher.c,v 1.82 2009/01/26 09:58:15 markus Exp $ */
3c0ef626	2	/*
	3	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	4	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	5	* All rights reserved
	6	*
	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
	12	*
	13	*
	14	* Copyright (c) 1999 Niels Provos. All rights reserved.
	15	* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
	16	*
	17	* Redistribution and use in source and binary forms, with or without
	18	* modification, are permitted provided that the following conditions
	19	* are met:
	20	* 1. Redistributions of source code must retain the above copyright
	21	* notice, this list of conditions and the following disclaimer.
	22	* 2. Redistributions in binary form must reproduce the above copyright
	23	* notice, this list of conditions and the following disclaimer in the
	24	* documentation and/or other materials provided with the distribution.
	25	*
	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	27	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	28	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	29	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	30	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	31	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	32	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	33	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	34	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	35	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	36	*/
	37
	38	#include "includes.h"
9108f8d9	39
	40	#include <sys/types.h>
	41
	42	#include <openssl/md5.h>
	43
	44	#include <string.h>
	45	#include <stdarg.h>
3c0ef626	46
	47	#include "xmalloc.h"
	48	#include "log.h"
	49	#include "cipher.h"
	50
665a873d	51	/* compatibility with old or broken OpenSSL versions */
665a873d	52	#include "openbsd-compat/openssl-compat.h"
cdd66111	53
0fff78ff	54	extern const EVP_CIPHER *evp_ssh1_bf(void);
	55	extern const EVP_CIPHER *evp_ssh1_3des(void);
	56	extern void ssh1_3des_iv(EVP_CIPHER_CTX , int, u_char , int);
	57	extern const EVP_CIPHER *evp_aes_128_ctr(void);
76d45d2f	58	extern const EVP_CIPHER *evp_aes_ctr_mt(void);
0fff78ff	59	extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX , int, u_char , u_int);
e9a17296	60
	61	struct Cipher {
	62	char *name;
	63	int number; /* for ssh1 only */
	64	u_int block_size;
	65	u_int key_len;
665a873d	66	u_int discard_len;
91d9cdd3	67	u_int cbc_mode;
f5799ae1	68	const EVP_CIPHER (evptype)(void);
e9a17296	69	} ciphers[] = {
91d9cdd3	70	{ "none", SSH_CIPHER_NONE, 8, 0, 0, 0, EVP_enc_null },
	71	{ "des", SSH_CIPHER_DES, 8, 8, 0, 1, EVP_des_cbc },
	72	{ "3des", SSH_CIPHER_3DES, 8, 16, 0, 1, evp_ssh1_3des },
	73	{ "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 1, evp_ssh1_bf },
	74
	75	{ "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 1, EVP_des_ede3_cbc },
	76	{ "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_bf_cbc },
	77	{ "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_cast5_cbc },
	78	{ "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, EVP_rc4 },
	79	{ "arcfour128", SSH_CIPHER_SSH2, 8, 16, 1536, 0, EVP_rc4 },
	80	{ "arcfour256", SSH_CIPHER_SSH2, 8, 32, 1536, 0, EVP_rc4 },
	81	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 1, EVP_aes_128_cbc },
	82	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 1, EVP_aes_192_cbc },
	83	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
700318f3	84	{ "rijndael-cbc@lysator.liu.se",
91d9cdd3	85	SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
76d45d2f	86	{ "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, evp_aes_ctr_mt },
	87	{ "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, evp_aes_ctr_mt },
	88	{ "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, evp_aes_ctr_mt },
665a873d	89	#ifdef USE_CIPHER_ACSS
91d9cdd3	90	{ "acss@openssh.org", SSH_CIPHER_SSH2, 16, 5, 0, 0, EVP_acss },
acc3d05e	91	#endif
91d9cdd3	92	{ NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, NULL }
e9a17296	93	};
3c0ef626	94
e9a17296	95	/--/
3c0ef626	96
700318f3	97	u_int
cdd66111	98	cipher_blocksize(const Cipher *c)
3c0ef626	99	{
e9a17296	100	return (c->block_size);
3c0ef626	101	}
680cee3b	102
700318f3	103	u_int
cdd66111	104	cipher_keylen(const Cipher *c)
3c0ef626	105	{
e9a17296	106	return (c->key_len);
3c0ef626	107	}
680cee3b	108
700318f3	109	u_int
cdd66111	110	cipher_get_number(const Cipher *c)
700318f3	111	{
	112	return (c->number);
	113	}
3c0ef626	114
91d9cdd3	115	u_int
	116	cipher_is_cbc(const Cipher *c)
	117	{
	118	return (c->cbc_mode);
	119	}
	120
3c0ef626	121	u_int
	122	cipher_mask_ssh1(int client)
	123	{
	124	u_int mask = 0;
e9a17296	125	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
3c0ef626	126	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	127	if (client) {
	128	mask \|= 1 << SSH_CIPHER_DES;
	129	}
	130	return mask;
	131	}
	132
	133	Cipher *
	134	cipher_by_name(const char *name)
	135	{
	136	Cipher *c;
	137	for (c = ciphers; c->name != NULL; c++)
996d5e62	138	if (strcmp(c->name, name) == 0)
3c0ef626	139	return c;
	140	return NULL;
	141	}
	142
	143	Cipher *
	144	cipher_by_number(int id)
	145	{
	146	Cipher *c;
	147	for (c = ciphers; c->name != NULL; c++)
	148	if (c->number == id)
	149	return c;
	150	return NULL;
	151	}
	152
	153	#define CIPHER_SEP ","
	154	int
	155	ciphers_valid(const char *names)
	156	{
	157	Cipher *c;
c9f39d2c	158	char cipher_list, cp;
3c0ef626	159	char *p;
	160
	161	if (names == NULL \|\| strcmp(names, "") == 0)
	162	return 0;
c9f39d2c	163	cipher_list = cp = xstrdup(names);
3c0ef626	164	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
e9a17296	165	(p = strsep(&cp, CIPHER_SEP))) {
3c0ef626	166	c = cipher_by_name(p);
76d45d2f	167	if (c == NULL \|\| (c->number != SSH_CIPHER_SSH2 &&
76d45d2f	168	c->number != SSH_CIPHER_NONE)) {
3c0ef626	169	debug("bad cipher %s [%s]", p, names);
c9f39d2c	170	xfree(cipher_list);
3c0ef626	171	return 0;
	172	} else {
	173	debug3("cipher ok: %s [%s]", p, names);
	174	}
	175	}
	176	debug3("ciphers ok: [%s]", names);
c9f39d2c	177	xfree(cipher_list);
3c0ef626	178	return 1;
	179	}
	180
	181	/*
	182	* Parses the name of the cipher. Returns the number of the corresponding
	183	* cipher, or -1 on error.
	184	*/
	185
	186	int
	187	cipher_number(const char *name)
	188	{
	189	Cipher *c;
	190	if (name == NULL)
	191	return -1;
996d5e62	192	for (c = ciphers; c->name != NULL; c++)
	193	if (strcasecmp(c->name, name) == 0)
	194	return c->number;
	195	return -1;
3c0ef626	196	}
	197
	198	char *
	199	cipher_name(int id)
	200	{
	201	Cipher *c = cipher_by_number(id);
	202	return (c==NULL) ? "<unknown>" : c->name;
	203	}
	204
	205	void
	206	cipher_init(CipherContext cc, Cipher cipher,
e9a17296	207	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
c9f39d2c	208	int do_encrypt)
3c0ef626	209	{
e9a17296	210	static int dowarn = 1;
700318f3	211	#ifdef SSH_OLD_EVP
	212	EVP_CIPHER *type;
	213	#else
e9a17296	214	const EVP_CIPHER *type;
e9a17296	215	int klen;
665a873d	216	#endif
665a873d	217	u_char junk, discard;
e9a17296	218
	219	if (cipher->number == SSH_CIPHER_DES) {
	220	if (dowarn) {
	221	error("Warning: use of DES is strongly discouraged "
	222	"due to cryptographic weaknesses");
	223	dowarn = 0;
	224	}
	225	if (keylen > 8)
	226	keylen = 8;
	227	}
	228	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	229
3c0ef626	230	if (keylen < cipher->key_len)
	231	fatal("cipher_init: key length %d is insufficient for %s.",
	232	keylen, cipher->name);
	233	if (iv != NULL && ivlen < cipher->block_size)
	234	fatal("cipher_init: iv length %d is insufficient for %s.",
	235	ivlen, cipher->name);
	236	cc->cipher = cipher;
e9a17296	237
	238	type = (*cipher->evptype)();
	239
	240	EVP_CIPHER_CTX_init(&cc->evp);
700318f3	241	#ifdef SSH_OLD_EVP
	242	if (type->key_len > 0 && type->key_len != keylen) {
	243	debug("cipher_init: set keylen (%d -> %d)",
	244	type->key_len, keylen);
	245	type->key_len = keylen;
	246	}
	247	EVP_CipherInit(&cc->evp, type, (u_char )key, (u_char )iv,
c9f39d2c	248	(do_encrypt == CIPHER_ENCRYPT));
700318f3	249	#else
e9a17296	250	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
c9f39d2c	251	(do_encrypt == CIPHER_ENCRYPT)) == 0)
e9a17296	252	fatal("cipher_init: EVP_CipherInit failed for %s",
	253	cipher->name);
	254	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
665a873d	255	if (klen > 0 && keylen != (u_int)klen) {
6a9b3198	256	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
e9a17296	257	if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
	258	fatal("cipher_init: set keylen failed (%d -> %d)",
	259	klen, keylen);
	260	}
	261	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
	262	fatal("cipher_init: EVP_CipherInit: set key failed for %s",
	263	cipher->name);
700318f3	264	#endif
665a873d	265
	266	if (cipher->discard_len > 0) {
	267	junk = xmalloc(cipher->discard_len);
	268	discard = xmalloc(cipher->discard_len);
	269	if (EVP_Cipher(&cc->evp, discard, junk,
	270	cipher->discard_len) == 0)
	271	fatal("evp_crypt: EVP_Cipher failed during discard");
	272	memset(discard, 0, cipher->discard_len);
	273	xfree(junk);
	274	xfree(discard);
	275	}
3c0ef626	276	}
	277
	278	void
e9a17296	279	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
3c0ef626	280	{
	281	if (len % cc->cipher->block_size)
	282	fatal("cipher_encrypt: bad plaintext length %d", len);
e9a17296	283	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
e9a17296	284	fatal("evp_crypt: EVP_Cipher failed");
3c0ef626	285	}
	286
	287	void
e9a17296	288	cipher_cleanup(CipherContext *cc)
3c0ef626	289	{
e9a17296	290	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
e9a17296	291	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
3c0ef626	292	}
	293
	294	/*
	295	* Selects the cipher, and keys if by computing the MD5 checksum of the
	296	* passphrase and using the resulting 16 bytes as the key.
	297	*/
	298
	299	void
	300	cipher_set_key_string(CipherContext cc, Cipher cipher,
c9f39d2c	301	const char *passphrase, int do_encrypt)
3c0ef626	302	{
	303	MD5_CTX md;
	304	u_char digest[16];
	305
	306	MD5_Init(&md);
	307	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
	308	MD5_Final(digest, &md);
	309
c9f39d2c	310	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);
3c0ef626	311
	312	memset(digest, 0, sizeof(digest));
	313	memset(&md, 0, sizeof(md));
	314	}
e9a17296	315
700318f3	316	/*
	317	* Exports an IV from the CipherContext required to export the key
	318	* state back from the unprivileged child to the privileged parent
	319	* process.
	320	*/
	321
	322	int
cdd66111	323	cipher_get_keyiv_len(const CipherContext *cc)
700318f3	324	{
	325	Cipher *c = cc->cipher;
	326	int ivlen;
	327
	328	if (c->number == SSH_CIPHER_3DES)
	329	ivlen = 24;
	330	else
	331	ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	332	return (ivlen);
	333	}
	334
	335	void
	336	cipher_get_keyiv(CipherContext cc, u_char iv, u_int len)
	337	{
	338	Cipher *c = cc->cipher;
700318f3	339	int evplen;
	340
	341	switch (c->number) {
76d45d2f	342	case SSH_CIPHER_NONE:
700318f3	343	case SSH_CIPHER_SSH2:
	344	case SSH_CIPHER_DES:
	345	case SSH_CIPHER_BLOWFISH:
	346	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
665a873d	347	if (evplen <= 0)
700318f3	348	return;
665a873d	349	if ((u_int)evplen != len)
f5799ae1	350	fatal("%s: wrong iv length %d != %d", __func__,
700318f3	351	evplen, len);
2c06c99b	352	#ifdef USE_BUILTIN_RIJNDAEL
0fff78ff	353	if (c->evptype == evp_rijndael)
	354	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	355	else
f5799ae1	356	#endif
0fff78ff	357	if (c->evptype == evp_aes_128_ctr)
	358	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	359	else
	360	memcpy(iv, cc->evp.iv, len);
	361	break;
	362	case SSH_CIPHER_3DES:
	363	ssh1_3des_iv(&cc->evp, 0, iv, 24);
700318f3	364	break;
700318f3	365	default:
f5799ae1	366	fatal("%s: bad cipher %d", __func__, c->number);
700318f3	367	}
700318f3	368	}
	369
	370	void
	371	cipher_set_keyiv(CipherContext cc, u_char iv)
	372	{
	373	Cipher *c = cc->cipher;
700318f3	374	int evplen = 0;
	375
	376	switch (c->number) {
76d45d2f	377	case SSH_CIPHER_NONE:
700318f3	378	case SSH_CIPHER_SSH2:
	379	case SSH_CIPHER_DES:
	380	case SSH_CIPHER_BLOWFISH:
	381	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	382	if (evplen == 0)
	383	return;
2c06c99b	384	#ifdef USE_BUILTIN_RIJNDAEL
0fff78ff	385	if (c->evptype == evp_rijndael)
	386	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	387	else
f5799ae1	388	#endif
0fff78ff	389	if (c->evptype == evp_aes_128_ctr)
	390	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	391	else
	392	memcpy(cc->evp.iv, iv, evplen);
	393	break;
	394	case SSH_CIPHER_3DES:
	395	ssh1_3des_iv(&cc->evp, 1, iv, 24);
700318f3	396	break;
700318f3	397	default:
f5799ae1	398	fatal("%s: bad cipher %d", __func__, c->number);
700318f3	399	}
700318f3	400	}
	401
	402	#if OPENSSL_VERSION_NUMBER < 0x00907000L
	403	#define EVP_X_STATE(evp) &(evp).c
	404	#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
	405	#else
	406	#define EVP_X_STATE(evp) (evp).cipher_data
	407	#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
	408	#endif
	409
	410	int
cdd66111	411	cipher_get_keycontext(const CipherContext cc, u_char dat)
700318f3	412	{
700318f3	413	Cipher *c = cc->cipher;
f5799ae1	414	int plen = 0;
700318f3	415
cdd66111	416	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
f5799ae1	417	plen = EVP_X_STATE_LEN(cc->evp);
700318f3	418	if (dat == NULL)
f5799ae1	419	return (plen);
f5799ae1	420	memcpy(dat, EVP_X_STATE(cc->evp), plen);
700318f3	421	}
700318f3	422	return (plen);
	423	}
	424
	425	void
	426	cipher_set_keycontext(CipherContext cc, u_char dat)
	427	{
	428	Cipher *c = cc->cipher;
	429	int plen;
	430
cdd66111	431	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
700318f3	432	plen = EVP_X_STATE_LEN(cc->evp);
	433	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	434	}
	435	}