- markus@cvs.openbsd.org 2003/05/15 03:08:29
[cipher.c cipher-bf1.c cipher-aes.c cipher-3des1.c]
split out custom EVP ciphers
diff --git a/cipher-3des1.c b/cipher-3des1.c
new file mode 100644
index 0000000..f9a3523
--- /dev/null
+++ b/cipher-3des1.c
@@ -0,0 +1,171 @@
+/*
+ * 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-3des1.c,v 1.1 2003/05/15 03:08:29 markus Exp $");
+
+#include <openssl/evp.h>
+#include "xmalloc.h"
+#include "log.h"
+
+/*
+ * 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.
+ */
+struct ssh1_3des_ctx
+{
+ EVP_CIPHER_CTX k1, k2, k3;
+};
+
+const EVP_CIPHER * evp_ssh1_3des(void);
+void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
+
+static int
+ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
+ int enc)
+{
+ struct ssh1_3des_ctx *c;
+ u_char *k1, *k2, *k3;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ c = xmalloc(sizeof(*c));
+ EVP_CIPHER_CTX_set_app_data(ctx, c);
+ }
+ if (key == NULL)
+ return (1);
+ if (enc == -1)
+ enc = ctx->encrypt;
+ k1 = k2 = k3 = (u_char *) key;
+ k2 += 8;
+ if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
+ if (enc)
+ k3 += 16;
+ else
+ k1 += 16;
+ }
+ EVP_CIPHER_CTX_init(&c->k1);
+ EVP_CIPHER_CTX_init(&c->k2);
+ EVP_CIPHER_CTX_init(&c->k3);
+#ifdef SSH_OLD_EVP
+ EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
+ EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
+ EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
+#else
+ if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
+ EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
+ EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
+ memset(c, 0, sizeof(*c));
+ xfree(c);
+ EVP_CIPHER_CTX_set_app_data(ctx, NULL);
+ return (0);
+ }
+#endif
+ return (1);
+}
+
+static int
+ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len)
+{
+ struct ssh1_3des_ctx *c;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ error("ssh1_3des_cbc: no context");
+ return (0);
+ }
+#ifdef SSH_OLD_EVP
+ EVP_Cipher(&c->k1, dest, (u_char *)src, len);
+ EVP_Cipher(&c->k2, dest, dest, len);
+ EVP_Cipher(&c->k3, dest, dest, len);
+#else
+ if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
+ EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
+ EVP_Cipher(&c->k3, dest, dest, len) == 0)
+ return (0);
+#endif
+ return (1);
+}
+
+static int
+ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
+{
+ struct ssh1_3des_ctx *c;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
+ memset(c, 0, sizeof(*c));
+ xfree(c);
+ EVP_CIPHER_CTX_set_app_data(ctx, NULL);
+ }
+ return (1);
+}
+
+void
+ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len)
+{
+ struct ssh1_3des_ctx *c;
+
+ if (len != 24)
+ fatal("%s: bad 3des iv length: %d", __func__, len);
+ if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
+ fatal("%s: no 3des context", __func__);
+ if (doset) {
+ debug3("%s: Installed 3DES IV", __func__);
+ memcpy(c->k1.iv, iv, 8);
+ memcpy(c->k2.iv, iv + 8, 8);
+ memcpy(c->k3.iv, iv + 16, 8);
+ } else {
+ debug3("%s: Copying 3DES IV", __func__);
+ memcpy(iv, c->k1.iv, 8);
+ memcpy(iv + 8, c->k2.iv, 8);
+ memcpy(iv + 16, c->k3.iv, 8);
+ }
+}
+
+const EVP_CIPHER *
+evp_ssh1_3des(void)
+{
+ static EVP_CIPHER ssh1_3des;
+
+ memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
+ ssh1_3des.nid = NID_undef;
+ ssh1_3des.block_size = 8;
+ ssh1_3des.iv_len = 0;
+ ssh1_3des.key_len = 16;
+ ssh1_3des.init = ssh1_3des_init;
+ ssh1_3des.cleanup = ssh1_3des_cleanup;
+ ssh1_3des.do_cipher = ssh1_3des_cbc;
+#ifndef SSH_OLD_EVP
+ ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
+#endif
+ return (&ssh1_3des);
+}