Damien Miller | f0a8ded | 2013-02-12 11:00:34 +1100 | [diff] [blame] | 1 | /* $OpenBSD: cipher.c,v 1.87 2013/01/26 06:11:05 djm Exp $ */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 6 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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". |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 12 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 13 | * |
| 14 | * Copyright (c) 1999 Niels Provos. All rights reserved. |
Ben Lindstrom | 4469723 | 2001-07-04 03:32:30 +0000 | [diff] [blame] | 15 | * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 36 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 37 | |
| 38 | #include "includes.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 39 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 40 | #include <sys/types.h> |
| 41 | |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 42 | #include <openssl/md5.h> |
| 43 | |
| 44 | #include <string.h> |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 45 | #include <stdarg.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 46 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 47 | #include "xmalloc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 48 | #include "log.h" |
| 49 | #include "cipher.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 50 | |
Darren Tucker | f0bd352 | 2005-06-17 21:15:20 +1000 | [diff] [blame] | 51 | /* compatibility with old or broken OpenSSL versions */ |
| 52 | #include "openbsd-compat/openssl-compat.h" |
| 53 | |
Damien Miller | 3a3261f | 2003-05-15 13:37:19 +1000 | [diff] [blame] | 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); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 57 | |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 58 | struct Cipher { |
| 59 | char *name; |
| 60 | int number; /* for ssh1 only */ |
| 61 | u_int block_size; |
| 62 | u_int key_len; |
Damien Miller | d522c68 | 2013-01-09 16:42:47 +1100 | [diff] [blame] | 63 | u_int iv_len; /* defaults to block_size */ |
| 64 | u_int auth_len; |
Damien Miller | 3710f27 | 2005-05-26 12:19:17 +1000 | [diff] [blame] | 65 | u_int discard_len; |
Damien Miller | 13ae44c | 2009-01-28 16:38:41 +1100 | [diff] [blame] | 66 | u_int cbc_mode; |
Ben Lindstrom | 6a24641 | 2002-06-06 19:48:16 +0000 | [diff] [blame] | 67 | const EVP_CIPHER *(*evptype)(void); |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 68 | } ciphers[] = { |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 69 | { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null }, |
| 70 | { "des", SSH_CIPHER_DES, 8, 8, 0, 0, 0, 1, EVP_des_cbc }, |
| 71 | { "3des", SSH_CIPHER_3DES, 8, 16, 0, 0, 0, 1, evp_ssh1_3des }, |
| 72 | { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 0, 0, 1, evp_ssh1_bf }, |
| 73 | |
| 74 | { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc }, |
| 75 | { "blowfish-cbc", |
| 76 | SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_bf_cbc }, |
| 77 | { "cast128-cbc", |
| 78 | SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_cast5_cbc }, |
| 79 | { "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 0, EVP_rc4 }, |
| 80 | { "arcfour128", SSH_CIPHER_SSH2, 8, 16, 0, 0, 1536, 0, EVP_rc4 }, |
| 81 | { "arcfour256", SSH_CIPHER_SSH2, 8, 32, 0, 0, 1536, 0, EVP_rc4 }, |
| 82 | { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc }, |
| 83 | { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc }, |
| 84 | { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, |
| 85 | { "rijndael-cbc@lysator.liu.se", |
| 86 | SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, |
| 87 | { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr }, |
| 88 | { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr }, |
| 89 | { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr }, |
Damien Miller | d522c68 | 2013-01-09 16:42:47 +1100 | [diff] [blame] | 90 | #ifdef OPENSSL_HAVE_EVPGCM |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 91 | { "aes128-gcm@openssh.com", |
| 92 | SSH_CIPHER_SSH2, 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm }, |
| 93 | { "aes256-gcm@openssh.com", |
| 94 | SSH_CIPHER_SSH2, 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm }, |
Damien Miller | d522c68 | 2013-01-09 16:42:47 +1100 | [diff] [blame] | 95 | #endif |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 96 | { NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, 0, 0, NULL } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 97 | }; |
| 98 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 99 | /*--*/ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 100 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 101 | u_int |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 102 | cipher_blocksize(const Cipher *c) |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 103 | { |
| 104 | return (c->block_size); |
| 105 | } |
Ben Lindstrom | 836f0e9 | 2002-06-23 21:21:30 +0000 | [diff] [blame] | 106 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 107 | u_int |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 108 | cipher_keylen(const Cipher *c) |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 109 | { |
| 110 | return (c->key_len); |
| 111 | } |
Ben Lindstrom | 836f0e9 | 2002-06-23 21:21:30 +0000 | [diff] [blame] | 112 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 113 | u_int |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 114 | cipher_authlen(const Cipher *c) |
| 115 | { |
| 116 | return (c->auth_len); |
| 117 | } |
| 118 | |
| 119 | u_int |
| 120 | cipher_ivlen(const Cipher *c) |
| 121 | { |
| 122 | return (c->iv_len ? c->iv_len : c->block_size); |
| 123 | } |
| 124 | |
| 125 | u_int |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 126 | cipher_get_number(const Cipher *c) |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 127 | { |
| 128 | return (c->number); |
| 129 | } |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 130 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 131 | u_int |
Damien Miller | 13ae44c | 2009-01-28 16:38:41 +1100 | [diff] [blame] | 132 | cipher_is_cbc(const Cipher *c) |
| 133 | { |
| 134 | return (c->cbc_mode); |
| 135 | } |
| 136 | |
| 137 | u_int |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 138 | cipher_mask_ssh1(int client) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 139 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 140 | u_int mask = 0; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 141 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 142 | mask |= 1 << SSH_CIPHER_BLOWFISH; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 143 | if (client) { |
| 144 | mask |= 1 << SSH_CIPHER_DES; |
| 145 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 146 | return mask; |
| 147 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 148 | |
| 149 | Cipher * |
| 150 | cipher_by_name(const char *name) |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 151 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 152 | Cipher *c; |
| 153 | for (c = ciphers; c->name != NULL; c++) |
Darren Tucker | 660db78 | 2005-01-24 21:57:11 +1100 | [diff] [blame] | 154 | if (strcmp(c->name, name) == 0) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 155 | return c; |
| 156 | return NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 157 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 158 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 159 | Cipher * |
| 160 | cipher_by_number(int id) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 161 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 162 | Cipher *c; |
| 163 | for (c = ciphers; c->name != NULL; c++) |
| 164 | if (c->number == id) |
| 165 | return c; |
| 166 | return NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 167 | } |
| 168 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 169 | #define CIPHER_SEP "," |
| 170 | int |
| 171 | ciphers_valid(const char *names) |
| 172 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 173 | Cipher *c; |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 174 | char *cipher_list, *cp; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 175 | char *p; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 176 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 177 | if (names == NULL || strcmp(names, "") == 0) |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 178 | return 0; |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 179 | cipher_list = cp = xstrdup(names); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 180 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 181 | (p = strsep(&cp, CIPHER_SEP))) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 182 | c = cipher_by_name(p); |
| 183 | if (c == NULL || c->number != SSH_CIPHER_SSH2) { |
| 184 | debug("bad cipher %s [%s]", p, names); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 185 | xfree(cipher_list); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 186 | return 0; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 187 | } else { |
Damien Miller | 50a41ed | 2000-10-16 12:14:42 +1100 | [diff] [blame] | 188 | debug3("cipher ok: %s [%s]", p, names); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 189 | } |
| 190 | } |
Damien Miller | 50a41ed | 2000-10-16 12:14:42 +1100 | [diff] [blame] | 191 | debug3("ciphers ok: [%s]", names); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 192 | xfree(cipher_list); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 193 | return 1; |
| 194 | } |
| 195 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 196 | /* |
| 197 | * Parses the name of the cipher. Returns the number of the corresponding |
| 198 | * cipher, or -1 on error. |
| 199 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 200 | |
| 201 | int |
| 202 | cipher_number(const char *name) |
| 203 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 204 | Cipher *c; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 205 | if (name == NULL) |
| 206 | return -1; |
Darren Tucker | 660db78 | 2005-01-24 21:57:11 +1100 | [diff] [blame] | 207 | for (c = ciphers; c->name != NULL; c++) |
| 208 | if (strcasecmp(c->name, name) == 0) |
| 209 | return c->number; |
| 210 | return -1; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 211 | } |
| 212 | |
| 213 | char * |
| 214 | cipher_name(int id) |
| 215 | { |
| 216 | Cipher *c = cipher_by_number(id); |
| 217 | return (c==NULL) ? "<unknown>" : c->name; |
| 218 | } |
| 219 | |
| 220 | void |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 221 | cipher_init(CipherContext *cc, Cipher *cipher, |
| 222 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 223 | int do_encrypt) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 224 | { |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 225 | static int dowarn = 1; |
Damien Miller | c7375ac | 2002-03-11 10:51:17 +1100 | [diff] [blame] | 226 | #ifdef SSH_OLD_EVP |
| 227 | EVP_CIPHER *type; |
| 228 | #else |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 229 | const EVP_CIPHER *type; |
| 230 | int klen; |
Darren Tucker | a55ec77 | 2005-06-09 21:45:10 +1000 | [diff] [blame] | 231 | #endif |
Damien Miller | 3710f27 | 2005-05-26 12:19:17 +1000 | [diff] [blame] | 232 | u_char *junk, *discard; |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 233 | |
| 234 | if (cipher->number == SSH_CIPHER_DES) { |
| 235 | if (dowarn) { |
| 236 | error("Warning: use of DES is strongly discouraged " |
| 237 | "due to cryptographic weaknesses"); |
| 238 | dowarn = 0; |
| 239 | } |
| 240 | if (keylen > 8) |
| 241 | keylen = 8; |
| 242 | } |
| 243 | cc->plaintext = (cipher->number == SSH_CIPHER_NONE); |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 244 | cc->encrypt = do_encrypt; |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 245 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 246 | if (keylen < cipher->key_len) |
| 247 | fatal("cipher_init: key length %d is insufficient for %s.", |
| 248 | keylen, cipher->name); |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 249 | if (iv != NULL && ivlen < cipher_ivlen(cipher)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 250 | fatal("cipher_init: iv length %d is insufficient for %s.", |
| 251 | ivlen, cipher->name); |
| 252 | cc->cipher = cipher; |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 253 | |
| 254 | type = (*cipher->evptype)(); |
| 255 | |
| 256 | EVP_CIPHER_CTX_init(&cc->evp); |
Damien Miller | c7375ac | 2002-03-11 10:51:17 +1100 | [diff] [blame] | 257 | #ifdef SSH_OLD_EVP |
| 258 | if (type->key_len > 0 && type->key_len != keylen) { |
| 259 | debug("cipher_init: set keylen (%d -> %d)", |
| 260 | type->key_len, keylen); |
| 261 | type->key_len = keylen; |
| 262 | } |
| 263 | EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, |
Darren Tucker | e5a604f | 2004-06-23 12:28:31 +1000 | [diff] [blame] | 264 | (do_encrypt == CIPHER_ENCRYPT)); |
Damien Miller | c7375ac | 2002-03-11 10:51:17 +1100 | [diff] [blame] | 265 | #else |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 266 | if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 267 | (do_encrypt == CIPHER_ENCRYPT)) == 0) |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 268 | fatal("cipher_init: EVP_CipherInit failed for %s", |
| 269 | cipher->name); |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 270 | if (cipher_authlen(cipher) && |
| 271 | !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED, |
| 272 | -1, (u_char *)iv)) |
| 273 | fatal("cipher_init: EVP_CTRL_GCM_SET_IV_FIXED failed for %s", |
| 274 | cipher->name); |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 275 | klen = EVP_CIPHER_CTX_key_length(&cc->evp); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 276 | if (klen > 0 && keylen != (u_int)klen) { |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 277 | debug2("cipher_init: set keylen (%d -> %d)", klen, keylen); |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 278 | if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) |
| 279 | fatal("cipher_init: set keylen failed (%d -> %d)", |
| 280 | klen, keylen); |
| 281 | } |
| 282 | if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) |
| 283 | fatal("cipher_init: EVP_CipherInit: set key failed for %s", |
| 284 | cipher->name); |
Damien Miller | c7375ac | 2002-03-11 10:51:17 +1100 | [diff] [blame] | 285 | #endif |
Damien Miller | 3710f27 | 2005-05-26 12:19:17 +1000 | [diff] [blame] | 286 | |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 287 | if (cipher->discard_len > 0) { |
Damien Miller | 3710f27 | 2005-05-26 12:19:17 +1000 | [diff] [blame] | 288 | junk = xmalloc(cipher->discard_len); |
| 289 | discard = xmalloc(cipher->discard_len); |
| 290 | if (EVP_Cipher(&cc->evp, discard, junk, |
| 291 | cipher->discard_len) == 0) |
| 292 | fatal("evp_crypt: EVP_Cipher failed during discard"); |
| 293 | memset(discard, 0, cipher->discard_len); |
| 294 | xfree(junk); |
| 295 | xfree(discard); |
| 296 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 297 | } |
| 298 | |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 299 | /* |
| 300 | * cipher_crypt() operates as following: |
| 301 | * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'. |
| 302 | * Theses bytes are treated as additional authenticated data for |
| 303 | * authenticated encryption modes. |
| 304 | * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'. |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 305 | * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag. |
| 306 | * This tag is written on encryption and verified on decryption. |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 307 | * Both 'aadlen' and 'authlen' can be set to 0. |
| 308 | */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 309 | void |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 310 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 311 | u_int len, u_int aadlen, u_int authlen) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 312 | { |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 313 | if (authlen) { |
| 314 | u_char lastiv[1]; |
| 315 | |
| 316 | if (authlen != cipher_authlen(cc->cipher)) |
| 317 | fatal("%s: authlen mismatch %d", __func__, authlen); |
| 318 | /* increment IV */ |
| 319 | if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, |
| 320 | 1, lastiv)) |
| 321 | fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__); |
| 322 | /* set tag on decyption */ |
| 323 | if (!cc->encrypt && |
| 324 | !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG, |
| 325 | authlen, (u_char *)src + aadlen + len)) |
| 326 | fatal("%s: EVP_CTRL_GCM_SET_TAG", __func__); |
| 327 | } |
| 328 | if (aadlen) { |
| 329 | if (authlen && |
| 330 | EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0) |
| 331 | fatal("%s: EVP_Cipher(aad) failed", __func__); |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 332 | memcpy(dest, src, aadlen); |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 333 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 334 | if (len % cc->cipher->block_size) |
Damien Miller | af43a7a | 2012-12-12 10:46:31 +1100 | [diff] [blame] | 335 | fatal("%s: bad plaintext length %d", __func__, len); |
| 336 | if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen, |
| 337 | len) < 0) |
| 338 | fatal("%s: EVP_Cipher failed", __func__); |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 339 | if (authlen) { |
| 340 | /* compute tag (on encrypt) or verify tag (on decrypt) */ |
Damien Miller | c20eb8b | 2013-01-12 22:41:26 +1100 | [diff] [blame] | 341 | if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) { |
| 342 | if (cc->encrypt) |
| 343 | fatal("%s: EVP_Cipher(final) failed", __func__); |
| 344 | else |
| 345 | fatal("Decryption integrity check failed"); |
| 346 | } |
Damien Miller | 1d75abf | 2013-01-09 16:12:19 +1100 | [diff] [blame] | 347 | if (cc->encrypt && |
| 348 | !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG, |
| 349 | authlen, dest + aadlen + len)) |
| 350 | fatal("%s: EVP_CTRL_GCM_GET_TAG", __func__); |
| 351 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 352 | } |
| 353 | |
| 354 | void |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 355 | cipher_cleanup(CipherContext *cc) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 356 | { |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 357 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) |
| 358 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 359 | } |
| 360 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 361 | /* |
| 362 | * Selects the cipher, and keys if by computing the MD5 checksum of the |
| 363 | * passphrase and using the resulting 16 bytes as the key. |
| 364 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 365 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 366 | void |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 367 | cipher_set_key_string(CipherContext *cc, Cipher *cipher, |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 368 | const char *passphrase, int do_encrypt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 369 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 370 | MD5_CTX md; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 371 | u_char digest[16]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 372 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 373 | MD5_Init(&md); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 374 | MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 375 | MD5_Final(digest, &md); |
| 376 | |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 377 | cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 378 | |
| 379 | memset(digest, 0, sizeof(digest)); |
| 380 | memset(&md, 0, sizeof(md)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 381 | } |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 382 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 383 | /* |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 384 | * Exports an IV from the CipherContext required to export the key |
| 385 | * state back from the unprivileged child to the privileged parent |
| 386 | * process. |
| 387 | */ |
| 388 | |
| 389 | int |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 390 | cipher_get_keyiv_len(const CipherContext *cc) |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 391 | { |
| 392 | Cipher *c = cc->cipher; |
| 393 | int ivlen; |
| 394 | |
| 395 | if (c->number == SSH_CIPHER_3DES) |
| 396 | ivlen = 24; |
| 397 | else |
| 398 | ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); |
| 399 | return (ivlen); |
| 400 | } |
| 401 | |
| 402 | void |
| 403 | cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) |
| 404 | { |
| 405 | Cipher *c = cc->cipher; |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 406 | int evplen; |
| 407 | |
| 408 | switch (c->number) { |
| 409 | case SSH_CIPHER_SSH2: |
| 410 | case SSH_CIPHER_DES: |
| 411 | case SSH_CIPHER_BLOWFISH: |
| 412 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 413 | if (evplen <= 0) |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 414 | return; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 415 | if ((u_int)evplen != len) |
Ben Lindstrom | 7d9c38f | 2002-06-06 21:40:51 +0000 | [diff] [blame] | 416 | fatal("%s: wrong iv length %d != %d", __func__, |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 417 | evplen, len); |
Darren Tucker | 129d0bb | 2005-12-19 17:40:40 +1100 | [diff] [blame] | 418 | #ifdef USE_BUILTIN_RIJNDAEL |
Damien Miller | a201bb3 | 2003-05-14 13:41:23 +1000 | [diff] [blame] | 419 | if (c->evptype == evp_rijndael) |
| 420 | ssh_rijndael_iv(&cc->evp, 0, iv, len); |
| 421 | else |
Ben Lindstrom | f088f43 | 2002-06-06 20:50:07 +0000 | [diff] [blame] | 422 | #endif |
Damien Miller | 25a02b0 | 2012-12-13 08:18:56 +1100 | [diff] [blame] | 423 | #ifndef OPENSSL_HAVE_EVPCTR |
Damien Miller | f5399c2 | 2003-05-18 20:53:59 +1000 | [diff] [blame] | 424 | if (c->evptype == evp_aes_128_ctr) |
| 425 | ssh_aes_ctr_iv(&cc->evp, 0, iv, len); |
| 426 | else |
Damien Miller | 25a02b0 | 2012-12-13 08:18:56 +1100 | [diff] [blame] | 427 | #endif |
| 428 | memcpy(iv, cc->evp.iv, len); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 429 | break; |
Damien Miller | a201bb3 | 2003-05-14 13:41:23 +1000 | [diff] [blame] | 430 | case SSH_CIPHER_3DES: |
| 431 | ssh1_3des_iv(&cc->evp, 0, iv, 24); |
| 432 | break; |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 433 | default: |
Ben Lindstrom | 7d9c38f | 2002-06-06 21:40:51 +0000 | [diff] [blame] | 434 | fatal("%s: bad cipher %d", __func__, c->number); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 435 | } |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 436 | } |
| 437 | |
| 438 | void |
| 439 | cipher_set_keyiv(CipherContext *cc, u_char *iv) |
| 440 | { |
| 441 | Cipher *c = cc->cipher; |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 442 | int evplen = 0; |
| 443 | |
| 444 | switch (c->number) { |
| 445 | case SSH_CIPHER_SSH2: |
| 446 | case SSH_CIPHER_DES: |
| 447 | case SSH_CIPHER_BLOWFISH: |
| 448 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); |
| 449 | if (evplen == 0) |
| 450 | return; |
Darren Tucker | 129d0bb | 2005-12-19 17:40:40 +1100 | [diff] [blame] | 451 | #ifdef USE_BUILTIN_RIJNDAEL |
Damien Miller | a201bb3 | 2003-05-14 13:41:23 +1000 | [diff] [blame] | 452 | if (c->evptype == evp_rijndael) |
| 453 | ssh_rijndael_iv(&cc->evp, 1, iv, evplen); |
| 454 | else |
Ben Lindstrom | f088f43 | 2002-06-06 20:50:07 +0000 | [diff] [blame] | 455 | #endif |
Damien Miller | 25a02b0 | 2012-12-13 08:18:56 +1100 | [diff] [blame] | 456 | #ifndef OPENSSL_HAVE_EVPCTR |
Damien Miller | f5399c2 | 2003-05-18 20:53:59 +1000 | [diff] [blame] | 457 | if (c->evptype == evp_aes_128_ctr) |
| 458 | ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen); |
| 459 | else |
Damien Miller | 25a02b0 | 2012-12-13 08:18:56 +1100 | [diff] [blame] | 460 | #endif |
| 461 | memcpy(cc->evp.iv, iv, evplen); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 462 | break; |
Damien Miller | a201bb3 | 2003-05-14 13:41:23 +1000 | [diff] [blame] | 463 | case SSH_CIPHER_3DES: |
| 464 | ssh1_3des_iv(&cc->evp, 1, iv, 24); |
| 465 | break; |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 466 | default: |
Ben Lindstrom | 7d9c38f | 2002-06-06 21:40:51 +0000 | [diff] [blame] | 467 | fatal("%s: bad cipher %d", __func__, c->number); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 468 | } |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 469 | } |
| 470 | |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 471 | int |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 472 | cipher_get_keycontext(const CipherContext *cc, u_char *dat) |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 473 | { |
| 474 | Cipher *c = cc->cipher; |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 475 | int plen = 0; |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 476 | |
Damien Miller | f0a8ded | 2013-02-12 11:00:34 +1100 | [diff] [blame] | 477 | if (c->evptype == EVP_rc4) { |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 478 | plen = EVP_X_STATE_LEN(cc->evp); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 479 | if (dat == NULL) |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 480 | return (plen); |
| 481 | memcpy(dat, EVP_X_STATE(cc->evp), plen); |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 482 | } |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 483 | return (plen); |
| 484 | } |
| 485 | |
| 486 | void |
| 487 | cipher_set_keycontext(CipherContext *cc, u_char *dat) |
| 488 | { |
| 489 | Cipher *c = cc->cipher; |
| 490 | int plen; |
| 491 | |
Damien Miller | f0a8ded | 2013-02-12 11:00:34 +1100 | [diff] [blame] | 492 | if (c->evptype == EVP_rc4) { |
Ben Lindstrom | 212faca | 2002-03-22 01:39:44 +0000 | [diff] [blame] | 493 | plen = EVP_X_STATE_LEN(cc->evp); |
| 494 | memcpy(EVP_X_STATE(cc->evp), dat, plen); |
| 495 | } |
Damien Miller | 21cf4e0 | 2002-02-19 15:26:42 +1100 | [diff] [blame] | 496 | } |