[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 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_128_ctr },
	{ "aes192-ctr",		SSH_CIPHER_SSH2, 16, 24, 0, 0, evp_aes_128_ctr },
	{ "aes256-ctr",		SSH_CIPHER_SSH2, 16, 32, 0, 0, evp_aes_128_ctr },
#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
16eb0a3b	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"
2e437378	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
34fee935	51	/* compatibility with old or broken OpenSSL versions */
34fee935	52	#include "openbsd-compat/openssl-compat.h"
416fd2a8	53
70791e56	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);
	58	extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX , int, u_char , u_int);
1e608e42	59
	60	struct Cipher {
	61	char *name;
	62	int number; /* for ssh1 only */
	63	u_int block_size;
	64	u_int key_len;
34fee935	65	u_int discard_len;
16eb0a3b	66	u_int cbc_mode;
ff2d7a98	67	const EVP_CIPHER (evptype)(void);
1e608e42	68	} ciphers[] = {
16eb0a3b	69	{ "none", SSH_CIPHER_NONE, 8, 0, 0, 0, EVP_enc_null },
	70	{ "des", SSH_CIPHER_DES, 8, 8, 0, 1, EVP_des_cbc },
	71	{ "3des", SSH_CIPHER_3DES, 8, 16, 0, 1, evp_ssh1_3des },
	72	{ "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 1, evp_ssh1_bf },
34fee935	73
16eb0a3b	74	{ "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 1, EVP_des_ede3_cbc },
	75	{ "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_bf_cbc },
	76	{ "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, 0, 1, EVP_cast5_cbc },
	77	{ "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, EVP_rc4 },
	78	{ "arcfour128", SSH_CIPHER_SSH2, 8, 16, 1536, 0, EVP_rc4 },
	79	{ "arcfour256", SSH_CIPHER_SSH2, 8, 32, 1536, 0, EVP_rc4 },
	80	{ "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 1, EVP_aes_128_cbc },
	81	{ "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 1, EVP_aes_192_cbc },
	82	{ "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
2980ea68	83	{ "rijndael-cbc@lysator.liu.se",
16eb0a3b	84	SSH_CIPHER_SSH2, 16, 32, 0, 1, EVP_aes_256_cbc },
46201ce0	85	{ "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, evp_aes_128_ctr },
	86	{ "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, evp_aes_128_ctr },
	87	{ "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, evp_aes_128_ctr },
34fee935	88	#ifdef USE_CIPHER_ACSS
16eb0a3b	89	{ "acss@openssh.org", SSH_CIPHER_SSH2, 16, 5, 0, 0, EVP_acss },
70791e56	90	#endif
16eb0a3b	91	{ NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, NULL }
1e608e42	92	};
3c0ef626	93
1e608e42	94	/--/
3c0ef626	95
1e608e42	96	u_int
416fd2a8	97	cipher_blocksize(const Cipher *c)
3c0ef626	98	{
1e608e42	99	return (c->block_size);
3c0ef626	100	}
ff2d7a98	101
1e608e42	102	u_int
416fd2a8	103	cipher_keylen(const Cipher *c)
3c0ef626	104	{
1e608e42	105	return (c->key_len);
3c0ef626	106	}
ff2d7a98	107
1e608e42	108	u_int
416fd2a8	109	cipher_get_number(const Cipher *c)
3c0ef626	110	{
1e608e42	111	return (c->number);
3c0ef626	112	}
3c0ef626	113
16eb0a3b	114	u_int
	115	cipher_is_cbc(const Cipher *c)
	116	{
	117	return (c->cbc_mode);
	118	}
	119
3c0ef626	120	u_int
	121	cipher_mask_ssh1(int client)
	122	{
	123	u_int mask = 0;
1e608e42	124	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
3c0ef626	125	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	126	if (client) {
	127	mask \|= 1 << SSH_CIPHER_DES;
	128	}
	129	return mask;
	130	}
	131
	132	Cipher *
	133	cipher_by_name(const char *name)
	134	{
	135	Cipher *c;
	136	for (c = ciphers; c->name != NULL; c++)
34fee935	137	if (strcmp(c->name, name) == 0)
3c0ef626	138	return c;
	139	return NULL;
	140	}
	141
	142	Cipher *
	143	cipher_by_number(int id)
	144	{
	145	Cipher *c;
	146	for (c = ciphers; c->name != NULL; c++)
	147	if (c->number == id)
	148	return c;
	149	return NULL;
	150	}
	151
	152	#define CIPHER_SEP ","
	153	int
	154	ciphers_valid(const char *names)
	155	{
	156	Cipher *c;
1b56ff3d	157	char cipher_list, cp;
3c0ef626	158	char *p;
	159
	160	if (names == NULL \|\| strcmp(names, "") == 0)
	161	return 0;
1b56ff3d	162	cipher_list = cp = xstrdup(names);
3c0ef626	163	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1e608e42	164	(p = strsep(&cp, CIPHER_SEP))) {
3c0ef626	165	c = cipher_by_name(p);
e00da40d	166	if (c == NULL \|\| (c->number != SSH_CIPHER_SSH2 &&
e00da40d	167	c->number != SSH_CIPHER_NONE)) {
3c0ef626	168	debug("bad cipher %s [%s]", p, names);
1b56ff3d	169	xfree(cipher_list);
3c0ef626	170	return 0;
	171	} else {
	172	debug3("cipher ok: %s [%s]", p, names);
	173	}
	174	}
	175	debug3("ciphers ok: [%s]", names);
1b56ff3d	176	xfree(cipher_list);
3c0ef626	177	return 1;
	178	}
	179
	180	/*
	181	* Parses the name of the cipher. Returns the number of the corresponding
	182	* cipher, or -1 on error.
	183	*/
	184
	185	int
	186	cipher_number(const char *name)
	187	{
	188	Cipher *c;
	189	if (name == NULL)
	190	return -1;
34fee935	191	for (c = ciphers; c->name != NULL; c++)
	192	if (strcasecmp(c->name, name) == 0)
	193	return c->number;
	194	return -1;
3c0ef626	195	}
	196
	197	char *
	198	cipher_name(int id)
	199	{
	200	Cipher *c = cipher_by_number(id);
	201	return (c==NULL) ? "<unknown>" : c->name;
	202	}
	203
	204	void
	205	cipher_init(CipherContext cc, Cipher cipher,
1e608e42	206	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
1b56ff3d	207	int do_encrypt)
3c0ef626	208	{
1e608e42	209	static int dowarn = 1;
2980ea68	210	#ifdef SSH_OLD_EVP
	211	EVP_CIPHER *type;
	212	#else
1e608e42	213	const EVP_CIPHER *type;
1e608e42	214	int klen;
34fee935	215	#endif
34fee935	216	u_char junk, discard;
1e608e42	217
	218	if (cipher->number == SSH_CIPHER_DES) {
	219	if (dowarn) {
	220	error("Warning: use of DES is strongly discouraged "
	221	"due to cryptographic weaknesses");
	222	dowarn = 0;
	223	}
	224	if (keylen > 8)
	225	keylen = 8;
	226	}
	227	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	228
3c0ef626	229	if (keylen < cipher->key_len)
	230	fatal("cipher_init: key length %d is insufficient for %s.",
	231	keylen, cipher->name);
	232	if (iv != NULL && ivlen < cipher->block_size)
	233	fatal("cipher_init: iv length %d is insufficient for %s.",
	234	ivlen, cipher->name);
	235	cc->cipher = cipher;
1e608e42	236
	237	type = (*cipher->evptype)();
	238
	239	EVP_CIPHER_CTX_init(&cc->evp);
2980ea68	240	#ifdef SSH_OLD_EVP
	241	if (type->key_len > 0 && type->key_len != keylen) {
	242	debug("cipher_init: set keylen (%d -> %d)",
	243	type->key_len, keylen);
	244	type->key_len = keylen;
	245	}
	246	EVP_CipherInit(&cc->evp, type, (u_char )key, (u_char )iv,
1b56ff3d	247	(do_encrypt == CIPHER_ENCRYPT));
2980ea68	248	#else
1e608e42	249	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
1b56ff3d	250	(do_encrypt == CIPHER_ENCRYPT)) == 0)
1e608e42	251	fatal("cipher_init: EVP_CipherInit failed for %s",
	252	cipher->name);
	253	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
34fee935	254	if (klen > 0 && keylen != (u_int)klen) {
1c14df9e	255	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
1e608e42	256	if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
	257	fatal("cipher_init: set keylen failed (%d -> %d)",
	258	klen, keylen);
	259	}
	260	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
	261	fatal("cipher_init: EVP_CipherInit: set key failed for %s",
	262	cipher->name);
2980ea68	263	#endif
34fee935	264
	265	if (cipher->discard_len > 0) {
	266	junk = xmalloc(cipher->discard_len);
	267	discard = xmalloc(cipher->discard_len);
	268	if (EVP_Cipher(&cc->evp, discard, junk,
	269	cipher->discard_len) == 0)
	270	fatal("evp_crypt: EVP_Cipher failed during discard");
	271	memset(discard, 0, cipher->discard_len);
	272	xfree(junk);
	273	xfree(discard);
	274	}
3c0ef626	275	}
	276
	277	void
1e608e42	278	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
3c0ef626	279	{
	280	if (len % cc->cipher->block_size)
	281	fatal("cipher_encrypt: bad plaintext length %d", len);
1e608e42	282	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
1e608e42	283	fatal("evp_crypt: EVP_Cipher failed");
3c0ef626	284	}
	285
	286	void
1e608e42	287	cipher_cleanup(CipherContext *cc)
3c0ef626	288	{
1e608e42	289	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
1e608e42	290	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
3c0ef626	291	}
	292
	293	/*
	294	* Selects the cipher, and keys if by computing the MD5 checksum of the
	295	* passphrase and using the resulting 16 bytes as the key.
	296	*/
	297
	298	void
	299	cipher_set_key_string(CipherContext cc, Cipher cipher,
1b56ff3d	300	const char *passphrase, int do_encrypt)
3c0ef626	301	{
	302	MD5_CTX md;
	303	u_char digest[16];
	304
	305	MD5_Init(&md);
	306	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
	307	MD5_Final(digest, &md);
	308
1b56ff3d	309	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);
3c0ef626	310
	311	memset(digest, 0, sizeof(digest));
	312	memset(&md, 0, sizeof(md));
	313	}
1e608e42	314
1e608e42	315	/*
	316	* Exports an IV from the CipherContext required to export the key
	317	* state back from the unprivileged child to the privileged parent
	318	* process.
	319	*/
	320
	321	int
416fd2a8	322	cipher_get_keyiv_len(const CipherContext *cc)
1e608e42	323	{
	324	Cipher *c = cc->cipher;
	325	int ivlen;
	326
	327	if (c->number == SSH_CIPHER_3DES)
	328	ivlen = 24;
	329	else
	330	ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	331	return (ivlen);
	332	}
	333
	334	void
	335	cipher_get_keyiv(CipherContext cc, u_char iv, u_int len)
	336	{
	337	Cipher *c = cc->cipher;
1e608e42	338	int evplen;
	339
	340	switch (c->number) {
34fee935	341	case SSH_CIPHER_NONE:
1e608e42	342	case SSH_CIPHER_SSH2:
	343	case SSH_CIPHER_DES:
	344	case SSH_CIPHER_BLOWFISH:
	345	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
34fee935	346	if (evplen <= 0)
1e608e42	347	return;
34fee935	348	if ((u_int)evplen != len)
ff2d7a98	349	fatal("%s: wrong iv length %d != %d", __func__,
1e608e42	350	evplen, len);
e00da40d	351	#ifdef USE_BUILTIN_RIJNDAEL
70791e56	352	if (c->evptype == evp_rijndael)
	353	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	354	else
ff2d7a98	355	#endif
70791e56	356	if (c->evptype == evp_aes_128_ctr)
	357	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	358	else
	359	memcpy(iv, cc->evp.iv, len);
	360	break;
	361	case SSH_CIPHER_3DES:
	362	ssh1_3des_iv(&cc->evp, 0, iv, 24);
1e608e42	363	break;
1e608e42	364	default:
ff2d7a98	365	fatal("%s: bad cipher %d", __func__, c->number);
1e608e42	366	}
1e608e42	367	}
	368
	369	void
	370	cipher_set_keyiv(CipherContext cc, u_char iv)
	371	{
	372	Cipher *c = cc->cipher;
1e608e42	373	int evplen = 0;
	374
	375	switch (c->number) {
34fee935	376	case SSH_CIPHER_NONE:
1e608e42	377	case SSH_CIPHER_SSH2:
	378	case SSH_CIPHER_DES:
	379	case SSH_CIPHER_BLOWFISH:
	380	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	381	if (evplen == 0)
	382	return;
e00da40d	383	#ifdef USE_BUILTIN_RIJNDAEL
70791e56	384	if (c->evptype == evp_rijndael)
	385	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	386	else
ff2d7a98	387	#endif
70791e56	388	if (c->evptype == evp_aes_128_ctr)
	389	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	390	else
	391	memcpy(cc->evp.iv, iv, evplen);
	392	break;
	393	case SSH_CIPHER_3DES:
	394	ssh1_3des_iv(&cc->evp, 1, iv, 24);
1e608e42	395	break;
1e608e42	396	default:
ff2d7a98	397	fatal("%s: bad cipher %d", __func__, c->number);
1e608e42	398	}
1e608e42	399	}
	400
	401	#if OPENSSL_VERSION_NUMBER < 0x00907000L
	402	#define EVP_X_STATE(evp) &(evp).c
	403	#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
	404	#else
	405	#define EVP_X_STATE(evp) (evp).cipher_data
	406	#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
	407	#endif
	408
	409	int
416fd2a8	410	cipher_get_keycontext(const CipherContext cc, u_char dat)
1e608e42	411	{
1e608e42	412	Cipher *c = cc->cipher;
ff2d7a98	413	int plen = 0;
1e608e42	414
416fd2a8	415	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
ff2d7a98	416	plen = EVP_X_STATE_LEN(cc->evp);
1e608e42	417	if (dat == NULL)
ff2d7a98	418	return (plen);
ff2d7a98	419	memcpy(dat, EVP_X_STATE(cc->evp), plen);
1e608e42	420	}
1e608e42	421	return (plen);
	422	}
	423
	424	void
	425	cipher_set_keycontext(CipherContext cc, u_char dat)
	426	{
	427	Cipher *c = cc->cipher;
	428	int plen;
	429
416fd2a8	430	if (c->evptype == EVP_rc4 \|\| c->evptype == EVP_acss) {
1e608e42	431	plen = EVP_X_STATE_LEN(cc->evp);
	432	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	433	}
	434	}