Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 2 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * cipher.c |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 4 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 6 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | * All rights reserved |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 9 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 10 | * Created: Wed Apr 19 17:41:39 1995 ylo |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 11 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 12 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 13 | |
| 14 | #include "includes.h" |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 15 | RCSID("$OpenBSD: cipher.c,v 1.29 2000/07/10 16:30:25 ho Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 16 | |
| 17 | #include "ssh.h" |
| 18 | #include "cipher.h" |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 19 | #include "xmalloc.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 20 | |
| 21 | #include <openssl/md5.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 22 | |
| 23 | /* |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 24 | * This is used by SSH1: |
| 25 | * |
| 26 | * What kind of triple DES are these 2 routines? |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 27 | * |
| 28 | * Why is there a redundant initialization vector? |
| 29 | * |
| 30 | * If only iv3 was used, then, this would till effect have been |
| 31 | * outer-cbc. However, there is also a private iv1 == iv2 which |
| 32 | * perhaps makes differential analysis easier. On the other hand, the |
| 33 | * private iv1 probably makes the CRC-32 attack ineffective. This is a |
| 34 | * result of that there is no longer any known iv1 to use when |
| 35 | * choosing the X block. |
| 36 | */ |
| 37 | void |
| 38 | SSH_3CBC_ENCRYPT(des_key_schedule ks1, |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 39 | des_key_schedule ks2, des_cblock * iv2, |
| 40 | des_key_schedule ks3, des_cblock * iv3, |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 41 | unsigned char *dest, unsigned char *src, |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 42 | unsigned int len) |
| 43 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 44 | des_cblock iv1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 45 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 46 | memcpy(&iv1, iv2, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 47 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 48 | des_cbc_encrypt(src, dest, len, ks1, &iv1, DES_ENCRYPT); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 49 | memcpy(&iv1, dest + len - 8, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 50 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 51 | des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_DECRYPT); |
| 52 | memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 53 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 54 | des_cbc_encrypt(dest, dest, len, ks3, iv3, DES_ENCRYPT); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 55 | memcpy(iv3, dest + len - 8, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | void |
| 59 | SSH_3CBC_DECRYPT(des_key_schedule ks1, |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 60 | des_key_schedule ks2, des_cblock * iv2, |
| 61 | des_key_schedule ks3, des_cblock * iv3, |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 62 | unsigned char *dest, unsigned char *src, |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 63 | unsigned int len) |
| 64 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 65 | des_cblock iv1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 66 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 67 | memcpy(&iv1, iv2, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 68 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 69 | des_cbc_encrypt(src, dest, len, ks3, iv3, DES_DECRYPT); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 70 | memcpy(iv3, src + len - 8, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 71 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 72 | des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_ENCRYPT); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 73 | memcpy(iv2, dest + len - 8, 8); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 74 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 75 | des_cbc_encrypt(dest, dest, len, ks1, &iv1, DES_DECRYPT); |
| 76 | /* memcpy(&iv1, iv2, 8); */ |
| 77 | /* Note how iv1 == iv2 on entry and exit. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 78 | } |
| 79 | |
| 80 | /* |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 81 | * SSH1 uses a variation on Blowfish, all bytes must be swapped before |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 82 | * and after encryption/decryption. Thus the swap_bytes stuff (yuk). |
| 83 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 84 | static void |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 85 | swap_bytes(const unsigned char *src, unsigned char *dst_, int n) |
| 86 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 87 | /* dst must be properly aligned. */ |
| 88 | u_int32_t *dst = (u_int32_t *) dst_; |
| 89 | union { |
| 90 | u_int32_t i; |
| 91 | char c[4]; |
| 92 | } t; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 93 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 94 | /* Process 8 bytes every lap. */ |
| 95 | for (n = n / 8; n > 0; n--) { |
| 96 | t.c[3] = *src++; |
| 97 | t.c[2] = *src++; |
| 98 | t.c[1] = *src++; |
| 99 | t.c[0] = *src++; |
| 100 | *dst++ = t.i; |
| 101 | |
| 102 | t.c[3] = *src++; |
| 103 | t.c[2] = *src++; |
| 104 | t.c[1] = *src++; |
| 105 | t.c[0] = *src++; |
| 106 | *dst++ = t.i; |
| 107 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 108 | } |
| 109 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 110 | /* |
| 111 | * Names of all encryption algorithms. |
| 112 | * These must match the numbers defined in cipher.h. |
| 113 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 114 | static char *cipher_names[] = |
| 115 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 116 | "none", |
| 117 | "idea", |
| 118 | "des", |
| 119 | "3des", |
| 120 | "tss", |
| 121 | "rc4", |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 122 | "blowfish", |
| 123 | "reserved", |
| 124 | "blowfish-cbc", |
| 125 | "3des-cbc", |
| 126 | "arcfour", |
| 127 | "cast128-cbc" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 128 | }; |
| 129 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 130 | /* |
| 131 | * Returns a bit mask indicating which ciphers are supported by this |
| 132 | * implementation. The bit mask has the corresponding bit set of each |
| 133 | * supported cipher. |
| 134 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 135 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 136 | unsigned int |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 137 | cipher_mask1() |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 138 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 139 | unsigned int mask = 0; |
| 140 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
| 141 | mask |= 1 << SSH_CIPHER_BLOWFISH; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 142 | return mask; |
| 143 | } |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 144 | unsigned int |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 145 | cipher_mask2() |
| 146 | { |
| 147 | unsigned int mask = 0; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 148 | mask |= 1 << SSH_CIPHER_BLOWFISH_CBC; |
| 149 | mask |= 1 << SSH_CIPHER_3DES_CBC; |
| 150 | mask |= 1 << SSH_CIPHER_ARCFOUR; |
| 151 | mask |= 1 << SSH_CIPHER_CAST128_CBC; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 152 | return mask; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 153 | } |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 154 | unsigned int |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 155 | cipher_mask() |
| 156 | { |
| 157 | return cipher_mask1() | cipher_mask2(); |
| 158 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 159 | |
| 160 | /* Returns the name of the cipher. */ |
| 161 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 162 | const char * |
| 163 | cipher_name(int cipher) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 164 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 165 | if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) || |
| 166 | cipher_names[cipher] == NULL) |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 167 | fatal("cipher_name: bad cipher name: %d", cipher); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 168 | return cipher_names[cipher]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 169 | } |
| 170 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 171 | /* Returns 1 if the name of the ciphers are valid. */ |
| 172 | |
| 173 | #define CIPHER_SEP "," |
| 174 | int |
| 175 | ciphers_valid(const char *names) |
| 176 | { |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 177 | char *ciphers, *cp; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 178 | char *p; |
| 179 | int i; |
| 180 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 181 | if (names == NULL || strcmp(names, "") == 0) |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 182 | return 0; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 183 | ciphers = cp = xstrdup(names); |
| 184 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; |
| 185 | (p = strsep(&cp, CIPHER_SEP))) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 186 | i = cipher_number(p); |
| 187 | if (i == -1 || !(cipher_mask2() & (1 << i))) { |
| 188 | xfree(ciphers); |
| 189 | return 0; |
| 190 | } |
| 191 | } |
| 192 | xfree(ciphers); |
| 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 | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 204 | int i; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 205 | if (name == NULL) |
| 206 | return -1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 207 | for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++) |
| 208 | if (strcmp(cipher_names[i], name) == 0 && |
| 209 | (cipher_mask() & (1 << i))) |
| 210 | return i; |
| 211 | return -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 212 | } |
| 213 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 214 | /* |
| 215 | * Selects the cipher, and keys if by computing the MD5 checksum of the |
| 216 | * passphrase and using the resulting 16 bytes as the key. |
| 217 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 218 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 219 | void |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 220 | cipher_set_key_string(CipherContext *context, int cipher, const char *passphrase) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 221 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 222 | MD5_CTX md; |
| 223 | unsigned char digest[16]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 224 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 225 | MD5_Init(&md); |
| 226 | MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase)); |
| 227 | MD5_Final(digest, &md); |
| 228 | |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 229 | cipher_set_key(context, cipher, digest, 16); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 230 | |
| 231 | memset(digest, 0, sizeof(digest)); |
| 232 | memset(&md, 0, sizeof(md)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 233 | } |
| 234 | |
| 235 | /* Selects the cipher to use and sets the key. */ |
| 236 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 237 | void |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 238 | cipher_set_key(CipherContext *context, int cipher, const unsigned char *key, |
| 239 | int keylen) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 240 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 241 | unsigned char padded[32]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 242 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 243 | /* Set cipher type. */ |
| 244 | context->type = cipher; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 245 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 246 | /* Get 32 bytes of key data. Pad if necessary. (So that code |
| 247 | below does not need to worry about key size). */ |
| 248 | memset(padded, 0, sizeof(padded)); |
| 249 | memcpy(padded, key, keylen < sizeof(padded) ? keylen : sizeof(padded)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 250 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 251 | /* Initialize the initialization vector. */ |
| 252 | switch (cipher) { |
| 253 | case SSH_CIPHER_NONE: |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 254 | /* |
| 255 | * Has to stay for authfile saving of private key with no |
| 256 | * passphrase |
| 257 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 258 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 259 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 260 | case SSH_CIPHER_3DES: |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 261 | /* |
| 262 | * Note: the least significant bit of each byte of key is |
| 263 | * parity, and must be ignored by the implementation. 16 |
| 264 | * bytes of key are used (first and last keys are the same). |
| 265 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 266 | if (keylen < 16) |
| 267 | error("Key length %d is insufficient for 3DES.", keylen); |
| 268 | des_set_key((void *) padded, context->u.des3.key1); |
| 269 | des_set_key((void *) (padded + 8), context->u.des3.key2); |
| 270 | if (keylen <= 16) |
| 271 | des_set_key((void *) padded, context->u.des3.key3); |
| 272 | else |
| 273 | des_set_key((void *) (padded + 16), context->u.des3.key3); |
| 274 | memset(context->u.des3.iv2, 0, sizeof(context->u.des3.iv2)); |
| 275 | memset(context->u.des3.iv3, 0, sizeof(context->u.des3.iv3)); |
| 276 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 277 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 278 | case SSH_CIPHER_BLOWFISH: |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 279 | if (keylen < 16) |
| 280 | error("Key length %d is insufficient for blowfish.", keylen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 281 | BF_set_key(&context->u.bf.key, keylen, padded); |
| 282 | memset(context->u.bf.iv, 0, 8); |
| 283 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 284 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 285 | case SSH_CIPHER_3DES_CBC: |
| 286 | case SSH_CIPHER_BLOWFISH_CBC: |
| 287 | case SSH_CIPHER_ARCFOUR: |
| 288 | case SSH_CIPHER_CAST128_CBC: |
| 289 | fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher)); |
| 290 | break; |
| 291 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 292 | default: |
| 293 | fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); |
| 294 | } |
| 295 | memset(padded, 0, sizeof(padded)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 296 | } |
| 297 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 298 | void |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 299 | cipher_set_key_iv(CipherContext * context, int cipher, |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 300 | const unsigned char *key, int keylen, |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 301 | const unsigned char *iv, int ivlen) |
| 302 | { |
| 303 | /* Set cipher type. */ |
| 304 | context->type = cipher; |
| 305 | |
| 306 | /* Initialize the initialization vector. */ |
| 307 | switch (cipher) { |
| 308 | case SSH_CIPHER_NONE: |
| 309 | break; |
| 310 | |
| 311 | case SSH_CIPHER_3DES: |
| 312 | case SSH_CIPHER_BLOWFISH: |
| 313 | fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher)); |
| 314 | break; |
| 315 | |
| 316 | case SSH_CIPHER_3DES_CBC: |
| 317 | if (keylen < 24) |
| 318 | error("Key length %d is insufficient for 3des-cbc.", keylen); |
| 319 | des_set_key((void *) key, context->u.des3.key1); |
| 320 | des_set_key((void *) (key+8), context->u.des3.key2); |
| 321 | des_set_key((void *) (key+16), context->u.des3.key3); |
| 322 | if (ivlen < 8) |
| 323 | error("IV length %d is insufficient for 3des-cbc.", ivlen); |
| 324 | memcpy(context->u.des3.iv3, (char *)iv, 8); |
| 325 | break; |
| 326 | |
| 327 | case SSH_CIPHER_BLOWFISH_CBC: |
| 328 | if (keylen < 16) |
| 329 | error("Key length %d is insufficient for blowfish.", keylen); |
| 330 | if (ivlen < 8) |
| 331 | error("IV length %d is insufficient for blowfish.", ivlen); |
| 332 | BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key); |
| 333 | memcpy(context->u.bf.iv, (char *)iv, 8); |
| 334 | break; |
| 335 | |
| 336 | case SSH_CIPHER_ARCFOUR: |
| 337 | if (keylen < 16) |
| 338 | error("Key length %d is insufficient for arcfour.", keylen); |
| 339 | RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key); |
| 340 | break; |
| 341 | |
| 342 | case SSH_CIPHER_CAST128_CBC: |
| 343 | if (keylen < 16) |
| 344 | error("Key length %d is insufficient for cast128.", keylen); |
| 345 | if (ivlen < 8) |
| 346 | error("IV length %d is insufficient for cast128.", ivlen); |
| 347 | CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key); |
| 348 | memcpy(context->u.cast.iv, (char *)iv, 8); |
| 349 | break; |
| 350 | |
| 351 | default: |
| 352 | fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); |
| 353 | } |
| 354 | } |
| 355 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 356 | /* Encrypts data using the cipher. */ |
| 357 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 358 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 359 | cipher_encrypt(CipherContext *context, unsigned char *dest, |
| 360 | const unsigned char *src, unsigned int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 361 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 362 | if ((len & 7) != 0) |
| 363 | fatal("cipher_encrypt: bad plaintext length %d", len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 364 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 365 | switch (context->type) { |
| 366 | case SSH_CIPHER_NONE: |
| 367 | memcpy(dest, src, len); |
| 368 | break; |
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 | case SSH_CIPHER_3DES: |
| 371 | SSH_3CBC_ENCRYPT(context->u.des3.key1, |
| 372 | context->u.des3.key2, &context->u.des3.iv2, |
| 373 | context->u.des3.key3, &context->u.des3.iv3, |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 374 | dest, (unsigned char *) src, len); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 375 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 376 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 377 | case SSH_CIPHER_BLOWFISH: |
| 378 | swap_bytes(src, dest, len); |
| 379 | BF_cbc_encrypt(dest, dest, len, |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 380 | &context->u.bf.key, context->u.bf.iv, |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 381 | BF_ENCRYPT); |
| 382 | swap_bytes(dest, dest, len); |
| 383 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 384 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 385 | case SSH_CIPHER_BLOWFISH_CBC: |
| 386 | BF_cbc_encrypt((void *)src, dest, len, |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 387 | &context->u.bf.key, context->u.bf.iv, |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 388 | BF_ENCRYPT); |
| 389 | break; |
| 390 | |
| 391 | case SSH_CIPHER_3DES_CBC: |
| 392 | des_ede3_cbc_encrypt(src, dest, len, |
| 393 | context->u.des3.key1, context->u.des3.key2, |
| 394 | context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT); |
| 395 | break; |
| 396 | |
| 397 | case SSH_CIPHER_ARCFOUR: |
| 398 | RC4(&context->u.rc4, len, (unsigned char *)src, dest); |
| 399 | break; |
| 400 | |
| 401 | case SSH_CIPHER_CAST128_CBC: |
| 402 | CAST_cbc_encrypt(src, dest, len, |
| 403 | &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT); |
| 404 | break; |
| 405 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 406 | default: |
| 407 | fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type)); |
| 408 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 409 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 410 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 411 | /* Decrypts data using the cipher. */ |
| 412 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 413 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 414 | cipher_decrypt(CipherContext *context, unsigned char *dest, |
| 415 | const unsigned char *src, unsigned int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 416 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 417 | if ((len & 7) != 0) |
| 418 | fatal("cipher_decrypt: bad ciphertext length %d", len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 419 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 420 | switch (context->type) { |
| 421 | case SSH_CIPHER_NONE: |
| 422 | memcpy(dest, src, len); |
| 423 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 424 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 425 | case SSH_CIPHER_3DES: |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 426 | SSH_3CBC_DECRYPT(context->u.des3.key1, |
| 427 | context->u.des3.key2, &context->u.des3.iv2, |
| 428 | context->u.des3.key3, &context->u.des3.iv3, |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 429 | dest, (unsigned char *) src, len); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 430 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 431 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 432 | case SSH_CIPHER_BLOWFISH: |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 433 | swap_bytes(src, dest, len); |
| 434 | BF_cbc_encrypt((void *) dest, dest, len, |
| 435 | &context->u.bf.key, context->u.bf.iv, |
| 436 | BF_DECRYPT); |
| 437 | swap_bytes(dest, dest, len); |
| 438 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 439 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 440 | case SSH_CIPHER_BLOWFISH_CBC: |
| 441 | BF_cbc_encrypt((void *) src, dest, len, |
| 442 | &context->u.bf.key, context->u.bf.iv, |
| 443 | BF_DECRYPT); |
| 444 | break; |
| 445 | |
| 446 | case SSH_CIPHER_3DES_CBC: |
| 447 | des_ede3_cbc_encrypt(src, dest, len, |
| 448 | context->u.des3.key1, context->u.des3.key2, |
| 449 | context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT); |
| 450 | break; |
| 451 | |
| 452 | case SSH_CIPHER_ARCFOUR: |
| 453 | RC4(&context->u.rc4, len, (unsigned char *)src, dest); |
| 454 | break; |
| 455 | |
| 456 | case SSH_CIPHER_CAST128_CBC: |
| 457 | CAST_cbc_encrypt(src, dest, len, |
| 458 | &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT); |
| 459 | break; |
| 460 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 461 | default: |
| 462 | fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type)); |
| 463 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 464 | } |