1 files changed, 125 insertions, 0 deletions
diff --git a/usr.sbin/xntpd/lib/auth12crypt.c b/usr.sbin/xntpd/lib/auth12crypt.c
new file mode 100644
index 0000000..a5d9889
--- /dev/null
+++ b/usr.sbin/xntpd/lib/auth12crypt.c
@@ -0,0 +1,125 @@
+/* auth12crypt.c,v 3.1 1993/07/06 01:07:43 jbj Exp
+ * auth12crypt.c - routines to support two stage NTP encryption
+ */
+#include "ntp_stdlib.h"
+
+/*
+ * For our purposes an NTP packet looks like:
+ *
+ *	a variable amount of encrypted data, multiple of 8 bytes, which
+ *		is encrypted in pass 1, followed by:
+ *	an 8 byte chunk of data which is encrypted in pass 2
+ *	NOCRYPT_OCTETS worth of unencrypted data, followed by:
+ *	BLOCK_OCTETS worth of ciphered checksum.
+ */ 
+#define	NOCRYPT_OCTETS	4
+#define	BLOCK_OCTETS	8
+
+#define	NOCRYPT_LONGS	((NOCRYPT_OCTETS)/sizeof(U_LONG))
+#define	BLOCK_LONGS	((BLOCK_OCTETS)/sizeof(U_LONG))
+
+/*
+ * Imported from the key data base module
+ */
+extern U_LONG cache_keyid;	/* cached key ID */
+extern u_char DEScache_ekeys[];	/* cached decryption keys */
+extern u_char DESzeroekeys[];	/* zero key decryption keys */
+
+/*
+ * Stat counters, from the database module
+ */
+extern U_LONG authencryptions;
+extern U_LONG authkeyuncached;
+extern U_LONG authnokey;
+
+
+/*
+ * auth1crypt - do the first stage of a two stage encryption
+ */
+void
+DESauth1crypt(keyno, pkt, length)
+	U_LONG keyno;
+	U_LONG *pkt;
+	int length;	/* length of all encrypted data */
+{
+	register U_LONG *pd;
+	register int i;
+	register u_char *keys;
+	U_LONG work[2];
+
+	authencryptions++;
+
+	if (keyno == 0) {
+		keys = DESzeroekeys;
+	} else {
+		if (keyno != cache_keyid) {
+			authkeyuncached++;
+			if (!authhavekey(keyno)) {
+				authnokey++;
+				return;
+			}
+		}
+		keys = DEScache_ekeys;
+	}
+
+	/*
+	 * Do the first five encryptions.  Stick the intermediate result
+	 * in the mac field.  The sixth encryption must wait until the
+	 * caller freezes a transmit time stamp, and will be done in stage 2.
+	 */
+	pd = pkt;
+	work[0] = work[1] = 0;
+
+	for (i = (length/BLOCK_OCTETS - 1); i > 0; i--) {
+		work[0] ^= *pd++;
+		work[1] ^= *pd++;
+		DESauth_des(work, keys);
+	}
+
+	/*
+	 * Space to the end of the packet and stick the intermediate
+	 * result in the mac field.
+	 */
+	pd += BLOCK_LONGS + NOCRYPT_LONGS;
+	*pd++ = work[0];
+	*pd = work[1];
+}
+
+
+/*
+ * auth2crypt - do the second stage of a two stage encryption
+ */
+int
+DESauth2crypt(keyno, pkt, length)
+	U_LONG keyno;
+	U_LONG *pkt;
+	int length;	/* total length of encrypted area */
+{
+	register U_LONG *pd;
+	register u_char *keys;
+
+	/*
+	 * Skip the key check.  The call to the first stage should
+	 * have got it.
+	 */
+	if (keyno == 0)
+		keys = DESzeroekeys;
+	else
+		keys = DEScache_ekeys;
+
+	/*
+	 * The mac currently should hold the results of the first `n'
+	 * encryptions.  We xor in the last block in data section and
+	 * do the final encryption in place.
+	 *
+	 * Get a pointer to the MAC block.  XOR in the last two words of
+	 * the data area. Call the encryption routine.
+	 */
+	pd = pkt + (length/sizeof(U_LONG)) + NOCRYPT_LONGS;
+
+	*pd ^= *(pd - NOCRYPT_LONGS - 2);
+	*(pd + 1) ^= *(pd - NOCRYPT_LONGS - 1);
+	DESauth_des(pd, keys);
+
+	return  4 + 8;		/* return size of key number and MAC */
+}