/*
- *
+ *
* cipher.c
- *
+ *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
+ *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
+ *
* Created: Wed Apr 19 17:41:39 1995 ylo
- *
+ *
*/
#include "includes.h"
#include "ssh.h"
#include "cipher.h"
+#include "xmalloc.h"
-#ifdef HAVE_OPENSSL
#include <openssl/md5.h>
-#endif
-#ifdef HAVE_SSL
-#include <ssl/md5.h>
-#endif
/*
- * What kind of tripple DES are these 2 routines?
+ * This is used by SSH1:
+ *
+ * What kind of triple DES are these 2 routines?
*
* Why is there a redundant initialization vector?
*
SSH_3CBC_ENCRYPT(des_key_schedule ks1,
des_key_schedule ks2, des_cblock * iv2,
des_key_schedule ks3, des_cblock * iv3,
- void *dest, void *src,
+ unsigned char *dest, unsigned char *src,
unsigned int len)
{
des_cblock iv1;
SSH_3CBC_DECRYPT(des_key_schedule ks1,
des_key_schedule ks2, des_cblock * iv2,
des_key_schedule ks3, des_cblock * iv3,
- void *dest, void *src,
+ unsigned char *dest, unsigned char *src,
unsigned int len)
{
des_cblock iv1;
}
/*
- * SSH uses a variation on Blowfish, all bytes must be swapped before
+ * SSH1 uses a variation on Blowfish, all bytes must be swapped before
* and after encryption/decryption. Thus the swap_bytes stuff (yuk).
*/
static void
}
}
-void (*cipher_attack_detected) (const char *fmt,...) = fatal;
-
-static inline void
-detect_cbc_attack(const unsigned char *src,
- unsigned int len)
-{
- return;
-
- log("CRC-32 CBC insertion attack detected");
- cipher_attack_detected("CRC-32 CBC insertion attack detected");
-}
-
-/* Names of all encryption algorithms. These must match the numbers defined
- int cipher.h. */
+/*
+ * Names of all encryption algorithms.
+ * These must match the numbers defined in cipher.h.
+ */
static char *cipher_names[] =
{
"none",
"3des",
"tss",
"rc4",
- "blowfish"
+ "blowfish",
+ "reserved",
+ "blowfish-cbc",
+ "3des-cbc",
+ "arcfour",
+ "cast128-cbc"
};
-/* Returns a bit mask indicating which ciphers are supported by this
- implementation. The bit mask has the corresponding bit set of each
- supported cipher. */
+/*
+ * Returns a bit mask indicating which ciphers are supported by this
+ * implementation. The bit mask has the corresponding bit set of each
+ * supported cipher.
+ */
-unsigned int
-cipher_mask()
+unsigned int
+cipher_mask1()
{
unsigned int mask = 0;
mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
mask |= 1 << SSH_CIPHER_BLOWFISH;
return mask;
}
+unsigned int
+cipher_mask2()
+{
+ unsigned int mask = 0;
+ mask |= 1 << SSH_CIPHER_BLOWFISH_CBC;
+ mask |= 1 << SSH_CIPHER_3DES_CBC;
+ mask |= 1 << SSH_CIPHER_ARCFOUR;
+ mask |= 1 << SSH_CIPHER_CAST128_CBC;
+ return mask;
+}
+unsigned int
+cipher_mask()
+{
+ return cipher_mask1() | cipher_mask2();
+}
/* Returns the name of the cipher. */
{
if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) ||
cipher_names[cipher] == NULL)
- fatal("cipher_name: bad cipher number: %d", cipher);
+ fatal("cipher_name: bad cipher name: %d", cipher);
return cipher_names[cipher];
}
-/* Parses the name of the cipher. Returns the number of the corresponding
- cipher, or -1 on error. */
+/* Returns 1 if the name of the ciphers are valid. */
+
+#define CIPHER_SEP ","
+int
+ciphers_valid(const char *names)
+{
+ char *ciphers;
+ char *p;
+ int i;
+
+ if (names == NULL || strcmp(names, "") == 0)
+ return 0;
+ ciphers = xstrdup(names);
+ for ((p = strtok(ciphers, CIPHER_SEP)); p; (p = strtok(NULL, CIPHER_SEP))) {
+ i = cipher_number(p);
+ if (i == -1 || !(cipher_mask2() & (1 << i))) {
+ xfree(ciphers);
+ return 0;
+ }
+ }
+ 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)
{
int i;
+ if (name == NULL)
+ return -1;
for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++)
if (strcmp(cipher_names[i], name) == 0 &&
(cipher_mask() & (1 << i)))
return -1;
}
-/* Selects the cipher, and keys if by computing the MD5 checksum of the
- passphrase and using the resulting 16 bytes as the key. */
+/*
+ * 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 *context, int cipher,
- const char *passphrase, int for_encryption)
+void
+cipher_set_key_string(CipherContext *context, int cipher, const char *passphrase)
{
MD5_CTX md;
unsigned char digest[16];
MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase));
MD5_Final(digest, &md);
- cipher_set_key(context, cipher, digest, 16, for_encryption);
+ cipher_set_key(context, cipher, digest, 16);
memset(digest, 0, sizeof(digest));
memset(&md, 0, sizeof(md));
/* Selects the cipher to use and sets the key. */
-void
-cipher_set_key(CipherContext *context, int cipher,
- const unsigned char *key, int keylen, int for_encryption)
+void
+cipher_set_key(CipherContext *context, int cipher, const unsigned char *key,
+ int keylen)
{
unsigned char padded[32];
/* Initialize the initialization vector. */
switch (cipher) {
case SSH_CIPHER_NONE:
- /* Has to stay for authfile saving of private key with
- no passphrase */
+ /*
+ * Has to stay for authfile saving of private key with no
+ * passphrase
+ */
break;
case SSH_CIPHER_3DES:
- /* Note: the least significant bit of each byte of key is
- parity, and must be ignored by the implementation. 16
- bytes of key are used (first and last keys are the
- same). */
+ /*
+ * Note: the least significant bit of each byte of key is
+ * parity, and must be ignored by the implementation. 16
+ * bytes of key are used (first and last keys are the same).
+ */
if (keylen < 16)
error("Key length %d is insufficient for 3DES.", keylen);
des_set_key((void *) padded, context->u.des3.key1);
break;
case SSH_CIPHER_BLOWFISH:
+ if (keylen < 16)
+ error("Key length %d is insufficient for blowfish.", keylen);
BF_set_key(&context->u.bf.key, keylen, padded);
memset(context->u.bf.iv, 0, 8);
break;
+ case SSH_CIPHER_3DES_CBC:
+ case SSH_CIPHER_BLOWFISH_CBC:
+ case SSH_CIPHER_ARCFOUR:
+ case SSH_CIPHER_CAST128_CBC:
+ fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher));
+ break;
+
default:
fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
}
memset(padded, 0, sizeof(padded));
}
+void
+cipher_set_key_iv(CipherContext * context, int cipher,
+ const unsigned char *key, int keylen,
+ const unsigned char *iv, int ivlen)
+{
+ /* Set cipher type. */
+ context->type = cipher;
+
+ /* Initialize the initialization vector. */
+ switch (cipher) {
+ case SSH_CIPHER_NONE:
+ break;
+
+ case SSH_CIPHER_3DES:
+ case SSH_CIPHER_BLOWFISH:
+ fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher));
+ break;
+
+ case SSH_CIPHER_3DES_CBC:
+ if (keylen < 24)
+ error("Key length %d is insufficient for 3des-cbc.", keylen);
+ des_set_key((void *) key, context->u.des3.key1);
+ des_set_key((void *) (key+8), context->u.des3.key2);
+ des_set_key((void *) (key+16), context->u.des3.key3);
+ if (ivlen < 8)
+ error("IV length %d is insufficient for 3des-cbc.", ivlen);
+ memcpy(context->u.des3.iv3, (char *)iv, 8);
+ break;
+
+ case SSH_CIPHER_BLOWFISH_CBC:
+ if (keylen < 16)
+ error("Key length %d is insufficient for blowfish.", keylen);
+ if (ivlen < 8)
+ error("IV length %d is insufficient for blowfish.", ivlen);
+ BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key);
+ memcpy(context->u.bf.iv, (char *)iv, 8);
+ break;
+
+ case SSH_CIPHER_ARCFOUR:
+ if (keylen < 16)
+ error("Key length %d is insufficient for arcfour.", keylen);
+ RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key);
+ break;
+
+ case SSH_CIPHER_CAST128_CBC:
+ if (keylen < 16)
+ error("Key length %d is insufficient for cast128.", keylen);
+ if (ivlen < 8)
+ error("IV length %d is insufficient for cast128.", ivlen);
+ CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key);
+ memcpy(context->u.cast.iv, (char *)iv, 8);
+ break;
+
+ default:
+ fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
+ }
+}
+
/* Encrypts data using the cipher. */
-void
+void
cipher_encrypt(CipherContext *context, unsigned char *dest,
const unsigned char *src, unsigned int len)
{
SSH_3CBC_ENCRYPT(context->u.des3.key1,
context->u.des3.key2, &context->u.des3.iv2,
context->u.des3.key3, &context->u.des3.iv3,
- dest, (void *) src, len);
+ dest, (unsigned char *) src, len);
break;
case SSH_CIPHER_BLOWFISH:
swap_bytes(src, dest, len);
BF_cbc_encrypt(dest, dest, len,
- &context->u.bf.key, context->u.bf.iv,
+ &context->u.bf.key, context->u.bf.iv,
BF_ENCRYPT);
swap_bytes(dest, dest, len);
break;
+ case SSH_CIPHER_BLOWFISH_CBC:
+ BF_cbc_encrypt((void *)src, dest, len,
+ &context->u.bf.key, context->u.bf.iv,
+ BF_ENCRYPT);
+ break;
+
+ case SSH_CIPHER_3DES_CBC:
+ des_ede3_cbc_encrypt(src, dest, len,
+ context->u.des3.key1, context->u.des3.key2,
+ context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT);
+ break;
+
+ case SSH_CIPHER_ARCFOUR:
+ RC4(&context->u.rc4, len, (unsigned char *)src, dest);
+ break;
+
+ case SSH_CIPHER_CAST128_CBC:
+ CAST_cbc_encrypt(src, dest, len,
+ &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT);
+ break;
+
default:
fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type));
}
/* Decrypts data using the cipher. */
-void
+void
cipher_decrypt(CipherContext *context, unsigned char *dest,
const unsigned char *src, unsigned int len)
{
break;
case SSH_CIPHER_3DES:
- /* CRC-32 attack? */
SSH_3CBC_DECRYPT(context->u.des3.key1,
context->u.des3.key2, &context->u.des3.iv2,
context->u.des3.key3, &context->u.des3.iv3,
- dest, (void *) src, len);
+ dest, (unsigned char *) src, len);
break;
case SSH_CIPHER_BLOWFISH:
- detect_cbc_attack(src, len);
swap_bytes(src, dest, len);
BF_cbc_encrypt((void *) dest, dest, len,
&context->u.bf.key, context->u.bf.iv,
swap_bytes(dest, dest, len);
break;
+ case SSH_CIPHER_BLOWFISH_CBC:
+ BF_cbc_encrypt((void *) src, dest, len,
+ &context->u.bf.key, context->u.bf.iv,
+ BF_DECRYPT);
+ break;
+
+ case SSH_CIPHER_3DES_CBC:
+ des_ede3_cbc_encrypt(src, dest, len,
+ context->u.des3.key1, context->u.des3.key2,
+ context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT);
+ break;
+
+ case SSH_CIPHER_ARCFOUR:
+ RC4(&context->u.rc4, len, (unsigned char *)src, dest);
+ break;
+
+ case SSH_CIPHER_CAST128_CBC:
+ CAST_cbc_encrypt(src, dest, len,
+ &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT);
+ break;
+
default:
fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type));
}
andersk / openssh.git / blobdiff