From ad0dcd9d49e2587c5482912b116053e6b3efd4b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Fri, 12 Mar 1999 17:24:11 +0100
Subject: [PATCH] * src/symmetric/include/cast.h, src/symmetric/cast.c: Added
consts. Added cast_selftest().
Rev: src/symmetric/cast.c:1.3
---
cast.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 82 insertions(+), 4 deletions(-)
diff --git a/cast.c b/cast.c
index d07451ec..d27ea696 100644
--- a/cast.c
+++ b/cast.c
@@ -5,10 +5,19 @@
* Written by Steve Reid <sreid@sea-to-sky.net>
* 100% Public Domain - no warranty
* Released 1997.10.11
+ *
+ * CAST-128 is documented in
+ * C. Adams, "The CAST-128 Encryption Algorithm", RFC 2144.
+ *
*/
/* Adapted to the pike cryptographic toolkit by Niels Möller */
+/* Selftest added by J.H.M. Dassen (Ray) <jdassen@wi.LeidenUniv.nl>.
+ * Released into the public domain. */
+
+#include <assert.h>
+
#include <cast.h>
#define u8 UINT8
@@ -42,7 +51,7 @@
/***** Encryption Function *****/
-void cast_encrypt(struct cast_key *key, u8 *inblock, u8 *outblock)
+void cast_encrypt(struct cast_key *key, const u8 * const inblock, u8 *outblock)
{
u32 t, l, r;
@@ -87,7 +96,7 @@ void cast_encrypt(struct cast_key *key, u8 *inblock, u8 *outblock)
/***** Decryption Function *****/
-void cast_decrypt(struct cast_key *key, u8 *inblock, u8 *outblock)
+void cast_decrypt(struct cast_key *key, const u8 * const inblock, u8 *outblock)
{
u32 t, l, r;
@@ -130,13 +139,82 @@ void cast_decrypt(struct cast_key *key, u8 *inblock, u8 *outblock)
}
-/***** Key Schedual *****/
+/* Sanity check using the test vectors from
+ * B.1. Single Plaintext-Key-Ciphertext Sets, RFC 2144
+ */
+int cast_selftest(void)
+{
+ u8 testkey128[16] = {
+ 0x01, 0x23, 0x45, 0x67, 0x12, 0x34, 0x56, 0x78,
+ 0x23, 0x45, 0x67, 0x89, 0x34, 0x56, 0x78, 0x9A
+ };
+ u8 plaintext128[8] = {
+ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF
+ };
+ u8 ciphertext128[8] = {
+ 0x23, 0x8B, 0x4F, 0xE5, 0x84, 0x7E, 0x44, 0xB2
+ };
+
+ u8 testkey80[10] = {
+ 0x01, 0x23, 0x45, 0x67, 0x12, 0x34, 0x56, 0x78,
+ 0x23, 0x45
+ };
+ u8 plaintext80[8] = {
+ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF
+ };
+ u8 ciphertext80[8] = {
+ 0xEB, 0x6A, 0x71, 0x1A, 0x2C, 0x02, 0x27, 0x1B
+ };
+
+ u8 testkey40[5] = {
+ 0x01, 0x23, 0x45, 0x67, 0x12
+ };
+ u8 plaintext40[8] = {
+ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF
+ };
+ u8 ciphertext40[8] = {
+ 0x7A, 0xC8, 0x16, 0xD1, 0x6E, 0x9B, 0x30, 0x2E
+ };
-void cast_setkey(struct cast_key *key, u8 *rawkey, unsigned keybytes)
+ struct cast_key context;
+ u8 ciphertext[8];
+
+ cast_setkey(&context, testkey128, 16);
+ cast_encrypt(&context, plaintext128, ciphertext);
+ if (memcmp(ciphertext, ciphertext128, 8)) {
+ return 0;
+ }
+ cast_setkey(&context, testkey80, 10);
+ cast_encrypt(&context, plaintext80, ciphertext);
+ if (memcmp(ciphertext, ciphertext80, 8)) {
+ return 0;
+ }
+ cast_setkey(&context, testkey40, 5);
+ cast_encrypt(&context, plaintext40, ciphertext);
+ if (memcmp(ciphertext, ciphertext40, 8)) {
+ return 0;
+ }
+ return 1;
+}
+
+
+/***** Key Schedule *****/
+
+void cast_setkey(struct cast_key *key, const u8 * const rawkey, unsigned keybytes)
{
u32 t[4], z[4], x[4];
unsigned i;
+#ifndef NDEBUG
+ static int initialized = 0;
+
+ if (!initialized)
+ {
+ initialized = 1;
+ assert(cast_selftest());
+ }
+#endif
+
/* Set number of rounds to 12 or 16, depending on key length */
key->rounds = (keybytes <= CAST_SMALL_KEY)
? CAST_SMALL_ROUNDS : CAST_FULL_ROUNDS;
--
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