1 files changed, 555 insertions, 0 deletions

diff --git a/other/ssharp/cipher.c b/other/ssharp/cipher.c
new file mode 100644
index 0000000..5350703
--- /dev/null
+++ b/other/ssharp/cipher.c
@@ -0,0 +1,555 @@
+/*
+ * 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 1.43 2001/02/04 15:32:23 stevesk Exp $");
+
+#include "xmalloc.h"
+#include "log.h"
+#include "cipher.h"
+
+#include <openssl/md5.h>
+
+
+/* no encryption */
+void
+none_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+}
+void
+none_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+}
+void
+none_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        memcpy(dest, src, len);
+}
+
+/* DES */
+void
+des_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        static int dowarn = 1;
+        if (dowarn) {
+                error("Warning: use of DES is strongly discouraged "
+                    "due to cryptographic weaknesses");
+                dowarn = 0;
+        }
+        des_set_key((void *)key, cc->u.des.key);
+}
+void
+des_ssh1_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+        memset(cc->u.des.iv, 0, sizeof(cc->u.des.iv));
+}
+void
+des_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
+            DES_ENCRYPT);
+}
+void
+des_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
+            DES_DECRYPT);
+}
+
+/* 3DES */
+void
+des3_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        des_set_key((void *) key, cc->u.des3.key1);
+        des_set_key((void *) (key+8), cc->u.des3.key2);
+        des_set_key((void *) (key+16), cc->u.des3.key3);
+}
+void
+des3_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+        memset(cc->u.des3.iv2, 0, sizeof(cc->u.des3.iv2));
+        memset(cc->u.des3.iv3, 0, sizeof(cc->u.des3.iv3));
+        if (iv == NULL)
+                return;
+        memcpy(cc->u.des3.iv3, (char *)iv, 8);
+}
+void
+des3_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        des_ede3_cbc_encrypt(src, dest, len,
+            cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
+            &cc->u.des3.iv3, DES_ENCRYPT);
+}
+void
+des3_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        des_ede3_cbc_encrypt(src, dest, len,
+            cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
+            &cc->u.des3.iv3, DES_DECRYPT);
+}
+
+/*
+ * This is used by SSH1:
+ *
+ * What kind of triple DES are these 2 routines?
+ *
+ * Why is there a redundant initialization vector?
+ *
+ * If only iv3 was used, then, this would till effect have been
+ * outer-cbc. However, there is also a private iv1 == iv2 which
+ * perhaps makes differential analysis easier. On the other hand, the
+ * private iv1 probably makes the CRC-32 attack ineffective. This is a
+ * result of that there is no longer any known iv1 to use when
+ * choosing the X block.
+ */
+void
+des3_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        des_set_key((void *) key, cc->u.des3.key1);
+        des_set_key((void *) (key+8), cc->u.des3.key2);
+        if (keylen <= 16)
+                des_set_key((void *) key, cc->u.des3.key3);
+        else
+                des_set_key((void *) (key+16), cc->u.des3.key3);
+}
+void
+des3_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        des_cblock iv1;
+        des_cblock *iv2 = &cc->u.des3.iv2;
+        des_cblock *iv3 = &cc->u.des3.iv3;
+
+        memcpy(&iv1, iv2, 8);
+
+        des_ncbc_encrypt(src,  dest, len, cc->u.des3.key1, &iv1, DES_ENCRYPT);
+        des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_DECRYPT);
+        des_ncbc_encrypt(dest, dest, len, cc->u.des3.key3, iv3, DES_ENCRYPT);
+}
+void
+des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        des_cblock iv1;
+        des_cblock *iv2 = &cc->u.des3.iv2;
+        des_cblock *iv3 = &cc->u.des3.iv3;
+
+        memcpy(&iv1, iv2, 8);
+
+        des_ncbc_encrypt(src,  dest, len, cc->u.des3.key3, iv3, DES_DECRYPT);
+        des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_ENCRYPT);
+        des_ncbc_encrypt(dest, dest, len, cc->u.des3.key1, &iv1, DES_DECRYPT);
+}
+
+/* Blowfish */
+void
+blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        BF_set_key(&cc->u.bf.key, keylen, (u_char *)key);
+}
+void
+blowfish_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+        if (iv == NULL)
+                memset(cc->u.bf.iv, 0, 8);
+        else
+                memcpy(cc->u.bf.iv, (char *)iv, 8);
+}
+void
+blowfish_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
+     u_int len)
+{
+        BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
+            BF_ENCRYPT);
+}
+void
+blowfish_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
+     u_int len)
+{
+        BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
+            BF_DECRYPT);
+}
+
+/*
+ * SSH1 uses a variation on Blowfish, all bytes must be swapped before
+ * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
+ */
+static void
+swap_bytes(const u_char *src, u_char *dst, int n)
+{
+        char c[4];
+
+        /* Process 4 bytes every lap. */
+        for (n = n / 4; n > 0; n--) {
+                c[3] = *src++;
+                c[2] = *src++;
+                c[1] = *src++;
+                c[0] = *src++;
+
+                *dst++ = c[0];
+                *dst++ = c[1];
+                *dst++ = c[2];
+                *dst++ = c[3];
+        }
+}
+
+void
+blowfish_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        swap_bytes(src, dest, len);
+        BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
+            BF_ENCRYPT);
+        swap_bytes(dest, dest, len);
+}
+void
+blowfish_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        swap_bytes(src, dest, len);
+        BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
+            BF_DECRYPT);
+        swap_bytes(dest, dest, len);
+}
+
+/* alleged rc4 */
+void
+arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        RC4_set_key(&cc->u.rc4, keylen, (u_char *)key);
+}
+void
+arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        RC4(&cc->u.rc4, len, (u_char *)src, dest);
+}
+
+/* CAST */
+void
+cast_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        CAST_set_key(&cc->u.cast.key, keylen, (u_char *) key);
+}
+void
+cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+        if (iv == NULL)
+                fatal("no IV for %s.", cc->cipher->name);
+        memcpy(cc->u.cast.iv, (char *)iv, 8);
+}
+void
+cast_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
+            CAST_ENCRYPT);
+}
+void
+cast_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
+            CAST_DECRYPT);
+}
+
+/* RIJNDAEL */
+
+#define RIJNDAEL_BLOCKSIZE 16
+void
+rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen)
+{
+        rijndael_set_key(&cc->u.rijndael.enc, (u4byte *)key, 8*keylen, 1);
+        rijndael_set_key(&cc->u.rijndael.dec, (u4byte *)key, 8*keylen, 0);
+}
+void
+rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
+{
+        if (iv == NULL)
+                fatal("no IV for %s.", cc->cipher->name);
+        memcpy((u_char *)cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
+}
+void
+rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        rijndael_ctx *ctx = &cc->u.rijndael.enc;
+        u4byte *iv = cc->u.rijndael.iv;
+        u4byte in[4];
+        u4byte *cprev, *cnow, *plain;
+        int i, blocks = len / RIJNDAEL_BLOCKSIZE;
+        if (len == 0)
+                return;
+        if (len % RIJNDAEL_BLOCKSIZE)
+                fatal("rijndael_cbc_encrypt: bad len %d", len);
+        cnow  = (u4byte*) dest;
+        plain = (u4byte*) src;
+        cprev = iv;
+        for(i = 0; i < blocks; i++, plain+=4, cnow+=4) {
+                in[0] = plain[0] ^ cprev[0];
+                in[1] = plain[1] ^ cprev[1];
+                in[2] = plain[2] ^ cprev[2];
+                in[3] = plain[3] ^ cprev[3];
+                rijndael_encrypt(ctx, in, cnow);
+                cprev = cnow;
+        }
+        memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
+}
+
+void
+rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
+    u_int len)
+{
+        rijndael_ctx *ctx = &cc->u.rijndael.dec;
+        u4byte *iv = cc->u.rijndael.iv;
+        u4byte ivsaved[4];
+        u4byte *cnow =  (u4byte*) (src+len-RIJNDAEL_BLOCKSIZE);
+        u4byte *plain = (u4byte*) (dest+len-RIJNDAEL_BLOCKSIZE);
+        u4byte *ivp;
+        int i, blocks = len / RIJNDAEL_BLOCKSIZE;
+        if (len == 0)
+                return;
+        if (len % RIJNDAEL_BLOCKSIZE)
+                fatal("rijndael_cbc_decrypt: bad len %d", len);
+        memcpy(ivsaved, cnow, RIJNDAEL_BLOCKSIZE);
+        for(i = blocks; i > 0; i--, cnow-=4, plain-=4) {
+                rijndael_decrypt(ctx, cnow, plain);
+                ivp =  (i == 1) ? iv : cnow-4;
+                plain[0] ^= ivp[0];
+                plain[1] ^= ivp[1];
+                plain[2] ^= ivp[2];
+                plain[3] ^= ivp[3];
+        }
+        memcpy(iv, ivsaved, RIJNDAEL_BLOCKSIZE);
+}
+
+Cipher ciphers[] = {
+        { "none",
+                SSH_CIPHER_NONE, 8, 0,
+                none_setkey, none_setiv,
+                none_crypt, none_crypt },
+        { "des",
+                SSH_CIPHER_DES, 8, 8,
+                des_ssh1_setkey, des_ssh1_setiv,
+                des_ssh1_encrypt, des_ssh1_decrypt },
+        { "3des",
+                SSH_CIPHER_3DES, 8, 16,
+                des3_ssh1_setkey, des3_setiv,
+                des3_ssh1_encrypt, des3_ssh1_decrypt },
+        { "blowfish",
+                SSH_CIPHER_BLOWFISH, 8, 16,
+                blowfish_setkey, blowfish_setiv,
+                blowfish_ssh1_encrypt, blowfish_ssh1_decrypt },
+
+        { "3des-cbc",
+                SSH_CIPHER_SSH2, 8, 24,
+                des3_setkey, des3_setiv,
+                des3_cbc_encrypt, des3_cbc_decrypt },
+        { "blowfish-cbc",
+                SSH_CIPHER_SSH2, 8, 16,
+                blowfish_setkey, blowfish_setiv,
+                blowfish_cbc_encrypt, blowfish_cbc_decrypt },
+        { "cast128-cbc",
+                SSH_CIPHER_SSH2, 8, 16,
+                cast_setkey, cast_setiv,
+                cast_cbc_encrypt, cast_cbc_decrypt },
+        { "arcfour",
+                SSH_CIPHER_SSH2, 8, 16,
+                arcfour_setkey, none_setiv,
+                arcfour_crypt, arcfour_crypt },
+        { "aes128-cbc",
+                SSH_CIPHER_SSH2, 16, 16,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "aes192-cbc",
+                SSH_CIPHER_SSH2, 16, 24,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "aes256-cbc",
+                SSH_CIPHER_SSH2, 16, 32,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "rijndael128-cbc",
+                SSH_CIPHER_SSH2, 16, 16,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "rijndael192-cbc",
+                SSH_CIPHER_SSH2, 16, 24,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "rijndael256-cbc",
+                SSH_CIPHER_SSH2, 16, 32,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { "rijndael-cbc@lysator.liu.se",
+                SSH_CIPHER_SSH2, 16, 32,
+                rijndael_setkey, rijndael_setiv,
+                rijndael_cbc_encrypt, rijndael_cbc_decrypt },
+        { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }
+};
+
+/*--*/
+
+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)
+{
+        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;
+        cipher->setkey(cc, key, keylen);
+        cipher->setiv(cc, iv, ivlen);
+}
+
+void
+cipher_encrypt(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);
+        cc->cipher->encrypt(cc, dest, src, len);
+}
+
+void
+cipher_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+        if (len % cc->cipher->block_size)
+                fatal("cipher_decrypt: bad ciphertext length %d", len);
+        cc->cipher->decrypt(cc, dest, src, len);
+}
+
+/*
+ * 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)
+{
+        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);
+
+        memset(digest, 0, sizeof(digest));
+        memset(&md, 0, sizeof(md));
+}