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

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 *
 *
 * Copyright (c) 1999 Niels Provos.  All rights reserved.
 * Copyright (c) 1999, 2000 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"
RCSID("$OpenBSD: cipher.c,v 1.65 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
	{ "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 },

	{ 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
3c0ef626	1	/*
	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	4	* All rights reserved
	5	*
	6	* As far as I am concerned, the code I have written for this software
	7	* can be used freely for any purpose. Any derived versions of this
	8	* software must be clearly marked as such, and if the derived work is
	9	* incompatible with the protocol description in the RFC file, it must be
	10	* called by a name other than "ssh" or "Secure Shell".
	11	*
	12	*
	13	* Copyright (c) 1999 Niels Provos. All rights reserved.
	14	* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions
	18	* are met:
	19	* 1. Redistributions of source code must retain the above copyright
	20	* notice, this list of conditions and the following disclaimer.
	21	* 2. Redistributions in binary form must reproduce the above copyright
	22	* notice, this list of conditions and the following disclaimer in the
	23	* documentation and/or other materials provided with the distribution.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	26	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	28	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	29	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	30	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	31	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	32	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	33	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	34	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	35	*/
	36
	37	#include "includes.h"
0fff78ff	38	RCSID("$OpenBSD: cipher.c,v 1.65 2003/05/17 04:27:52 markus Exp $");
3c0ef626	39
	40	#include "xmalloc.h"
	41	#include "log.h"
	42	#include "cipher.h"
	43
	44	#include <openssl/md5.h>
e9a17296	45
700318f3	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
f5799ae1	51	#if OPENSSL_VERSION_NUMBER < 0x00907000L
0fff78ff	52	extern const EVP_CIPHER *evp_rijndael(void);
0fff78ff	53	extern void ssh_rijndael_iv(EVP_CIPHER_CTX , int, u_char , u_int);
f5799ae1	54	#endif
0fff78ff	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);
	58	extern const EVP_CIPHER *evp_aes_128_ctr(void);
	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;
f5799ae1	66	const EVP_CIPHER (evptype)(void);
e9a17296	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 },
f5799ae1	77	#if OPENSSL_VERSION_NUMBER < 0x00907000L
e9a17296	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 },
700318f3	81	{ "rijndael-cbc@lysator.liu.se",
700318f3	82	SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
f5799ae1	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
0fff78ff	90	{ "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
	91	{ "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
	92	{ "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
e9a17296	93
	94	{ NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL }
	95	};
3c0ef626	96
e9a17296	97	/--/
3c0ef626	98
700318f3	99	u_int
e9a17296	100	cipher_blocksize(Cipher *c)
3c0ef626	101	{
e9a17296	102	return (c->block_size);
3c0ef626	103	}
680cee3b	104
700318f3	105	u_int
e9a17296	106	cipher_keylen(Cipher *c)
3c0ef626	107	{
e9a17296	108	return (c->key_len);
3c0ef626	109	}
680cee3b	110
700318f3	111	u_int
	112	cipher_get_number(Cipher *c)
	113	{
	114	return (c->number);
	115	}
3c0ef626	116
3c0ef626	117	u_int
	118	cipher_mask_ssh1(int client)
	119	{
	120	u_int mask = 0;
e9a17296	121	mask \|= 1 << SSH_CIPHER_3DES; /* Mandatory */
3c0ef626	122	mask \|= 1 << SSH_CIPHER_BLOWFISH;
	123	if (client) {
	124	mask \|= 1 << SSH_CIPHER_DES;
	125	}
	126	return mask;
	127	}
	128
	129	Cipher *
	130	cipher_by_name(const char *name)
	131	{
	132	Cipher *c;
	133	for (c = ciphers; c->name != NULL; c++)
	134	if (strcasecmp(c->name, name) == 0)
	135	return c;
	136	return NULL;
	137	}
	138
	139	Cipher *
	140	cipher_by_number(int id)
	141	{
	142	Cipher *c;
	143	for (c = ciphers; c->name != NULL; c++)
	144	if (c->number == id)
	145	return c;
	146	return NULL;
	147	}
	148
	149	#define CIPHER_SEP ","
	150	int
	151	ciphers_valid(const char *names)
	152	{
	153	Cipher *c;
	154	char ciphers, cp;
	155	char *p;
	156
	157	if (names == NULL \|\| strcmp(names, "") == 0)
	158	return 0;
	159	ciphers = cp = xstrdup(names);
	160	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
e9a17296	161	(p = strsep(&cp, CIPHER_SEP))) {
3c0ef626	162	c = cipher_by_name(p);
	163	if (c == NULL \|\| c->number != SSH_CIPHER_SSH2) {
	164	debug("bad cipher %s [%s]", p, names);
	165	xfree(ciphers);
	166	return 0;
	167	} else {
	168	debug3("cipher ok: %s [%s]", p, names);
	169	}
	170	}
	171	debug3("ciphers ok: [%s]", names);
	172	xfree(ciphers);
	173	return 1;
	174	}
	175
	176	/*
	177	* Parses the name of the cipher. Returns the number of the corresponding
	178	* cipher, or -1 on error.
	179	*/
	180
	181	int
	182	cipher_number(const char *name)
	183	{
	184	Cipher *c;
	185	if (name == NULL)
	186	return -1;
	187	c = cipher_by_name(name);
	188	return (c==NULL) ? -1 : c->number;
	189	}
	190
	191	char *
	192	cipher_name(int id)
	193	{
	194	Cipher *c = cipher_by_number(id);
	195	return (c==NULL) ? "<unknown>" : c->name;
	196	}
	197
	198	void
	199	cipher_init(CipherContext cc, Cipher cipher,
e9a17296	200	const u_char key, u_int keylen, const u_char iv, u_int ivlen,
e9a17296	201	int encrypt)
3c0ef626	202	{
e9a17296	203	static int dowarn = 1;
700318f3	204	#ifdef SSH_OLD_EVP
	205	EVP_CIPHER *type;
	206	#else
e9a17296	207	const EVP_CIPHER *type;
700318f3	208	#endif
e9a17296	209	int klen;
	210
	211	if (cipher->number == SSH_CIPHER_DES) {
	212	if (dowarn) {
	213	error("Warning: use of DES is strongly discouraged "
	214	"due to cryptographic weaknesses");
	215	dowarn = 0;
	216	}
	217	if (keylen > 8)
	218	keylen = 8;
	219	}
	220	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	221
3c0ef626	222	if (keylen < cipher->key_len)
	223	fatal("cipher_init: key length %d is insufficient for %s.",
	224	keylen, cipher->name);
	225	if (iv != NULL && ivlen < cipher->block_size)
	226	fatal("cipher_init: iv length %d is insufficient for %s.",
	227	ivlen, cipher->name);
	228	cc->cipher = cipher;
e9a17296	229
	230	type = (*cipher->evptype)();
	231
	232	EVP_CIPHER_CTX_init(&cc->evp);
700318f3	233	#ifdef SSH_OLD_EVP
	234	if (type->key_len > 0 && type->key_len != keylen) {
	235	debug("cipher_init: set keylen (%d -> %d)",
	236	type->key_len, keylen);
	237	type->key_len = keylen;
	238	}
	239	EVP_CipherInit(&cc->evp, type, (u_char )key, (u_char )iv,
	240	(encrypt == CIPHER_ENCRYPT));
	241	#else
e9a17296	242	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
	243	(encrypt == CIPHER_ENCRYPT)) == 0)
	244	fatal("cipher_init: EVP_CipherInit failed for %s",
	245	cipher->name);
	246	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	247	if (klen > 0 && keylen != klen) {
6a9b3198	248	debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
e9a17296	249	if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
	250	fatal("cipher_init: set keylen failed (%d -> %d)",
	251	klen, keylen);
	252	}
	253	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
	254	fatal("cipher_init: EVP_CipherInit: set key failed for %s",
	255	cipher->name);
700318f3	256	#endif
3c0ef626	257	}
	258
	259	void
e9a17296	260	cipher_crypt(CipherContext cc, u_char dest, const u_char *src, u_int len)
3c0ef626	261	{
	262	if (len % cc->cipher->block_size)
	263	fatal("cipher_encrypt: bad plaintext length %d", len);
700318f3	264	#ifdef SSH_OLD_EVP
	265	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
	266	#else
e9a17296	267	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
e9a17296	268	fatal("evp_crypt: EVP_Cipher failed");
700318f3	269	#endif
3c0ef626	270	}
	271
	272	void
e9a17296	273	cipher_cleanup(CipherContext *cc)
3c0ef626	274	{
700318f3	275	#ifdef SSH_OLD_EVP
	276	EVP_CIPHER_CTX_cleanup(&cc->evp);
	277	#else
e9a17296	278	if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
e9a17296	279	error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
700318f3	280	#endif
3c0ef626	281	}
	282
	283	/*
	284	* Selects the cipher, and keys if by computing the MD5 checksum of the
	285	* passphrase and using the resulting 16 bytes as the key.
	286	*/
	287
	288	void
	289	cipher_set_key_string(CipherContext cc, Cipher cipher,
e9a17296	290	const char *passphrase, int encrypt)
3c0ef626	291	{
	292	MD5_CTX md;
	293	u_char digest[16];
	294
	295	MD5_Init(&md);
	296	MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
	297	MD5_Final(digest, &md);
	298
e9a17296	299	cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt);
3c0ef626	300
	301	memset(digest, 0, sizeof(digest));
	302	memset(&md, 0, sizeof(md));
	303	}
e9a17296	304
700318f3	305	/*
	306	* Exports an IV from the CipherContext required to export the key
	307	* state back from the unprivileged child to the privileged parent
	308	* process.
	309	*/
	310
	311	int
	312	cipher_get_keyiv_len(CipherContext *cc)
	313	{
	314	Cipher *c = cc->cipher;
	315	int ivlen;
	316
	317	if (c->number == SSH_CIPHER_3DES)
	318	ivlen = 24;
	319	else
	320	ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	321	return (ivlen);
	322	}
	323
	324	void
	325	cipher_get_keyiv(CipherContext cc, u_char iv, u_int len)
	326	{
	327	Cipher *c = cc->cipher;
700318f3	328	int evplen;
	329
	330	switch (c->number) {
	331	case SSH_CIPHER_SSH2:
	332	case SSH_CIPHER_DES:
	333	case SSH_CIPHER_BLOWFISH:
	334	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	335	if (evplen == 0)
	336	return;
	337	if (evplen != len)
f5799ae1	338	fatal("%s: wrong iv length %d != %d", __func__,
700318f3	339	evplen, len);
f5799ae1	340	#if OPENSSL_VERSION_NUMBER < 0x00907000L
0fff78ff	341	if (c->evptype == evp_rijndael)
	342	ssh_rijndael_iv(&cc->evp, 0, iv, len);
	343	else
f5799ae1	344	#endif
0fff78ff	345	if (c->evptype == evp_aes_128_ctr)
	346	ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
	347	else
	348	memcpy(iv, cc->evp.iv, len);
	349	break;
	350	case SSH_CIPHER_3DES:
	351	ssh1_3des_iv(&cc->evp, 0, iv, 24);
700318f3	352	break;
700318f3	353	default:
f5799ae1	354	fatal("%s: bad cipher %d", __func__, c->number);
700318f3	355	}
700318f3	356	}
	357
	358	void
	359	cipher_set_keyiv(CipherContext cc, u_char iv)
	360	{
	361	Cipher *c = cc->cipher;
700318f3	362	int evplen = 0;
	363
	364	switch (c->number) {
	365	case SSH_CIPHER_SSH2:
	366	case SSH_CIPHER_DES:
	367	case SSH_CIPHER_BLOWFISH:
	368	evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
	369	if (evplen == 0)
	370	return;
f5799ae1	371	#if OPENSSL_VERSION_NUMBER < 0x00907000L
0fff78ff	372	if (c->evptype == evp_rijndael)
	373	ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
	374	else
f5799ae1	375	#endif
0fff78ff	376	if (c->evptype == evp_aes_128_ctr)
	377	ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
	378	else
	379	memcpy(cc->evp.iv, iv, evplen);
	380	break;
	381	case SSH_CIPHER_3DES:
	382	ssh1_3des_iv(&cc->evp, 1, iv, 24);
700318f3	383	break;
700318f3	384	default:
f5799ae1	385	fatal("%s: bad cipher %d", __func__, c->number);
700318f3	386	}
700318f3	387	}
	388
	389	#if OPENSSL_VERSION_NUMBER < 0x00907000L
	390	#define EVP_X_STATE(evp) &(evp).c
	391	#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
	392	#else
	393	#define EVP_X_STATE(evp) (evp).cipher_data
	394	#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
	395	#endif
	396
	397	int
	398	cipher_get_keycontext(CipherContext cc, u_char dat)
	399	{
	400	Cipher *c = cc->cipher;
f5799ae1	401	int plen = 0;
700318f3	402
f5799ae1	403	if (c->evptype == EVP_rc4) {
f5799ae1	404	plen = EVP_X_STATE_LEN(cc->evp);
700318f3	405	if (dat == NULL)
f5799ae1	406	return (plen);
f5799ae1	407	memcpy(dat, EVP_X_STATE(cc->evp), plen);
700318f3	408	}
700318f3	409	return (plen);
	410	}
	411
	412	void
	413	cipher_set_keycontext(CipherContext cc, u_char dat)
	414	{
	415	Cipher *c = cc->cipher;
	416	int plen;
	417
f5799ae1	418	if (c->evptype == EVP_rc4) {
700318f3	419	plen = EVP_X_STATE_LEN(cc->evp);
	420	memcpy(EVP_X_STATE(cc->evp), dat, plen);
	421	}
	422	}