a

libc/crypt.c

@@ -0,0 +1,68 @@
+/*
+ *	Data Encryption Standard
+ *	D.P.Mitchell  83/06/08.
+ *
+ *	block_cipher(key, block, decrypting)
+ *
+ *	these routines use the non-standard 7 byte format
+ *	for DES keys.
+ */
+#include <u.h>
+#include <libc.h>
+#include <auth.h>
+#include <libsec.h>
+
+/*
+ * destructively encrypt the buffer, which
+ * must be at least 8 characters long.
+ */
+int
+encrypt(void *key, void *vbuf, int n)
+{
+	ulong ekey[32];
+	uchar *buf;
+	int i, r;
+
+	if(n < 8)
+		return 0;
+	key_setup(key, ekey);
+	buf = vbuf;
+	n--;
+	r = n % 7;
+	n /= 7;
+	for(i = 0; i < n; i++){
+		block_cipher(ekey, buf, 0);
+		buf += 7;
+	}
+	if(r)
+		block_cipher(ekey, buf - 7 + r, 0);
+	return 1;
+}
+
+/*
+ * destructively decrypt the buffer, which
+ * must be at least 8 characters long.
+ */
+int
+decrypt(void *key, void *vbuf, int n)
+{
+	ulong ekey[128];
+	uchar *buf;
+	int i, r;
+
+	if(n < 8)
+		return 0;
+	key_setup(key, ekey);
+	buf = vbuf;
+	n--;
+	r = n % 7;
+	n /= 7;
+	buf += n * 7;
+	if(r)
+		block_cipher(ekey, buf - 7 + r, 1);
+	for(i = 0; i < n; i++){
+		buf -= 7;
+		block_cipher(ekey, buf, 1);
+	}
+	return 1;
+}