1 files changed, 97 insertions, 0 deletions
diff --git a/contrib/ntp/libntp/authencrypt.c b/contrib/ntp/libntp/authencrypt.c
new file mode 100644
index 0000000..22f910c
--- /dev/null
+++ b/contrib/ntp/libntp/authencrypt.c
@@ -0,0 +1,97 @@
+/*
+ * DES interface for rsaref2.0
+ *
+ * These routines implement an interface for the RSA Laboratories
+ * implementation of the Data Encryption Standard (DES) algorithm
+ * operating in Cipher-Block Chaining (CBC) mode. This algorithm is
+ * included in the rsaref2.0 package available from RSA in the US and
+ * foreign countries. Further information is available at www.rsa.com.
+ */
+
+#include "ntp_machine.h"
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef DES
+#include "ntp_types.h"
+#include "ntp_fp.h"
+#include "ntp_string.h"
+#include "global.h"
+#include "des.h"
+#include "ntp_stdlib.h"
+
+#define BLOCK_OCTETS	8	/* message digest size */
+#define MAXTPKT 	128 /* max packet size */
+
+
+/*
+ * DESauthencrypt - generate DES-CBC message authenticator
+ *
+ * Returns length of authenticator field.
+ */
+int
+DESauthencrypt(
+	u_char *key,		/* key pointer */
+	u_int32 *pkt,		/* packet pointer */
+	int length		/* packet length */
+	)
+{
+	DES_CBC_CTX ctx;
+	u_int32 tpkt[MAXTPKT];
+	u_int32 work[2];
+	int i, j;
+
+	/*
+	 * DES-CBC with zero IV. Note the encrypted text is discarded.
+	 */
+	work[0] = work[1] = 0;
+	DES_CBCInit(&ctx, key, (u_char *)work, 1);
+	DES_CBCUpdate(&ctx, (u_char *)tpkt, (u_char *)pkt,
+		(u_int)length);
+	i = length / 4 + 1;
+	j = i - 3;
+	pkt[i++] = (u_int32)htonl(tpkt[j++]);
+	pkt[i] = (u_int32)htonl(tpkt[j]);
+	return (BLOCK_OCTETS + 4);
+}
+
+
+/*
+ * DESauthdecrypt - verify DES message authenticator
+ *
+ * Returns one if authenticator valid, zero if invalid.
+ */
+int
+DESauthdecrypt(
+	u_char *key,		/* key pointer */
+	u_int32 *pkt,		/* packet pointer */
+	int length, 	/* packet length */
+	int size		/* size of MAC field */
+	)
+{
+	DES_CBC_CTX ctx;
+	u_int32 tpkt[MAXTPKT];
+	u_int32 work[2];
+	int i, j;
+
+	/*
+	 * DES-CBC with zero IV. Note the encrypted text is discarded.
+	 */
+	if (size != BLOCK_OCTETS + 4)
+		return (0);
+	work[0] = work[1] = 0;
+	DES_CBCInit (&ctx, key, (u_char *)work, 1);
+	DES_CBCUpdate (&ctx, (u_char *)tpkt, (u_char *)pkt,
+		(u_int)length);
+	i = length / 4 + 1;
+	j = i - 3;
+	if ((u_int32)ntohl(pkt[i++]) == tpkt[j++] &&
+		(u_int32)ntohl(pkt[i]) == tpkt[j])
+		return (1);
+	return (0);
+}
+#else
+int authencrypt_bs;
+#endif /* DES */