- markus@cvs.openbsd.org 2003/05/15 03:08:29

[openssh.git] / cipher-bf1.c

diff --git a/cipher-bf1.c b/cipher-bf1.c
new file mode 100644 (file)
index 0000000..64578ba
--- /dev/null
+++ b/cipher-bf1.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2003 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-bf1.c,v 1.1 2003/05/15 03:08:29 markus Exp $");
+
+#include <openssl/evp.h>
+#include "xmalloc.h"
+#include "log.h"
+/*
+ * SSH1 uses a variation on Blowfish, all bytes must be swapped before
+ * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
+ */
+
+const EVP_CIPHER * evp_ssh1_bf(void);
+
+static void
+swap_bytes(const u_char *src, u_char *dst, int n)
+{
+       u_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];
+       }
+}
+
+#ifdef SSH_OLD_EVP
+static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
+                         const unsigned char *iv, int enc)
+{
+       if (iv != NULL)
+               memcpy (&(ctx->oiv[0]), iv, 8);
+       memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
+       if (key != NULL)
+               BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
+                           key);
+}
+#endif
+
+static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
+
+static int
+bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
+{
+       int ret;
+
+       swap_bytes(in, out, len);
+       ret = (*orig_bf)(ctx, out, out, len);
+       swap_bytes(out, out, len);
+       return (ret);
+}
+
+const EVP_CIPHER *
+evp_ssh1_bf(void)
+{
+       static EVP_CIPHER ssh1_bf;
+
+       memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
+       orig_bf = ssh1_bf.do_cipher;
+       ssh1_bf.nid = NID_undef;
+#ifdef SSH_OLD_EVP
+       ssh1_bf.init = bf_ssh1_init;
+#endif
+       ssh1_bf.do_cipher = bf_ssh1_cipher;
+       ssh1_bf.key_len = 32;
+       return (&ssh1_bf);
+}