1 files changed, 259 insertions, 0 deletions
diff --git a/print-krb.c b/print-krb.c
new file mode 100644
index 0000000..959b555
--- /dev/null
+++ b/print-krb.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (c) 1995, 1996, 1997
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Initial contribution from John Hawkinson (jhawk@mit.edu).
+ */
+
+/* \summary: Kerberos printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "extract.h"
+
+/*
+ * Kerberos 4:
+ *
+ * Athena Technical Plan
+ * Section E.2.1
+ * Kerberos Authentication and Authorization System
+ * by S. P. Miller, B. C. Neuman, J. I. Schiller, and J. H. Saltzer
+ *
+ * https://web.mit.edu/Saltzer/www/publications/athenaplan/e.2.1.pdf
+ *
+ * 7. Appendix I Design Specifications
+ *
+ * Kerberos 5:
+ *
+ * RFC 1510, RFC 2630, etc.
+ */
+
+
+static const u_char *c_print(netdissect_options *, const u_char *, const u_char *);
+static const u_char *krb4_print_hdr(netdissect_options *, const u_char *);
+static void krb4_print(netdissect_options *, const u_char *);
+
+#define AUTH_MSG_KDC_REQUEST			1<<1
+#define AUTH_MSG_KDC_REPLY			2<<1
+#define AUTH_MSG_APPL_REQUEST			3<<1
+#define AUTH_MSG_APPL_REQUEST_MUTUAL		4<<1
+#define AUTH_MSG_ERR_REPLY			5<<1
+#define AUTH_MSG_PRIVATE			6<<1
+#define AUTH_MSG_SAFE				7<<1
+#define AUTH_MSG_APPL_ERR			8<<1
+#define AUTH_MSG_DIE				63<<1
+
+#define KERB_ERR_OK				0
+#define KERB_ERR_NAME_EXP			1
+#define KERB_ERR_SERVICE_EXP			2
+#define KERB_ERR_AUTH_EXP			3
+#define KERB_ERR_PKT_VER			4
+#define KERB_ERR_NAME_MAST_KEY_VER		5
+#define KERB_ERR_SERV_MAST_KEY_VER		6
+#define KERB_ERR_BYTE_ORDER			7
+#define KERB_ERR_PRINCIPAL_UNKNOWN		8
+#define KERB_ERR_PRINCIPAL_NOT_UNIQUE		9
+#define KERB_ERR_NULL_KEY			10
+
+struct krb {
+	nd_uint8_t pvno;	/* Protocol Version */
+	nd_uint8_t type;	/* Type+B */
+};
+
+static const struct tok type2str[] = {
+	{ AUTH_MSG_KDC_REQUEST,		"KDC_REQUEST" },
+	{ AUTH_MSG_KDC_REPLY,		"KDC_REPLY" },
+	{ AUTH_MSG_APPL_REQUEST,	"APPL_REQUEST" },
+	{ AUTH_MSG_APPL_REQUEST_MUTUAL,	"APPL_REQUEST_MUTUAL" },
+	{ AUTH_MSG_ERR_REPLY,		"ERR_REPLY" },
+	{ AUTH_MSG_PRIVATE,		"PRIVATE" },
+	{ AUTH_MSG_SAFE,		"SAFE" },
+	{ AUTH_MSG_APPL_ERR,		"APPL_ERR" },
+	{ AUTH_MSG_DIE,			"DIE" },
+	{ 0,				NULL }
+};
+
+static const struct tok kerr2str[] = {
+	{ KERB_ERR_OK,			"OK" },
+	{ KERB_ERR_NAME_EXP,		"NAME_EXP" },
+	{ KERB_ERR_SERVICE_EXP,		"SERVICE_EXP" },
+	{ KERB_ERR_AUTH_EXP,		"AUTH_EXP" },
+	{ KERB_ERR_PKT_VER,		"PKT_VER" },
+	{ KERB_ERR_NAME_MAST_KEY_VER,	"NAME_MAST_KEY_VER" },
+	{ KERB_ERR_SERV_MAST_KEY_VER,	"SERV_MAST_KEY_VER" },
+	{ KERB_ERR_BYTE_ORDER,		"BYTE_ORDER" },
+	{ KERB_ERR_PRINCIPAL_UNKNOWN,	"PRINCIPAL_UNKNOWN" },
+	{ KERB_ERR_PRINCIPAL_NOT_UNIQUE,"PRINCIPAL_NOT_UNIQUE" },
+	{ KERB_ERR_NULL_KEY,		"NULL_KEY"},
+	{ 0,				NULL}
+};
+
+static const u_char *
+c_print(netdissect_options *ndo,
+        const u_char *s, const u_char *ep)
+{
+	u_char c;
+	int flag;
+
+	flag = 1;
+	while (s < ep) {
+		c = GET_U_1(s);
+		s++;
+		if (c == '\0') {
+			flag = 0;
+			break;
+		}
+		fn_print_char(ndo, c);
+	}
+	if (flag)
+		return NULL;
+	return (s);
+}
+
+static const u_char *
+krb4_print_hdr(netdissect_options *ndo,
+               const u_char *cp)
+{
+	cp += 2;
+
+#define PRINT		if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
+
+	PRINT;
+	ND_PRINT(".");
+	PRINT;
+	ND_PRINT("@");
+	PRINT;
+	return (cp);
+
+trunc:
+	nd_print_trunc(ndo);
+	return (NULL);
+
+#undef PRINT
+}
+
+static void
+krb4_print(netdissect_options *ndo,
+           const u_char *cp)
+{
+	const struct krb *kp;
+	u_char type;
+	u_short len;
+
+#define PRINT		if ((cp = c_print(ndo, cp, ndo->ndo_snapend)) == NULL) goto trunc
+/*  True if struct krb is little endian */
+#define IS_LENDIAN(kp)	((GET_U_1((kp)->type) & 0x01) != 0)
+#define KTOHSP(kp, cp)	(IS_LENDIAN(kp) ? GET_LE_U_2(cp) : GET_BE_U_2(cp))
+
+	kp = (const struct krb *)cp;
+
+	type = GET_U_1(kp->type) & (0xFF << 1);
+
+	ND_PRINT(" %s %s: ",
+	    IS_LENDIAN(kp) ? "le" : "be", tok2str(type2str, NULL, type));
+
+	switch (type) {
+
+	case AUTH_MSG_KDC_REQUEST:
+		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
+			return;
+		cp += 4;	/* ctime */
+		ND_PRINT(" %umin ", GET_U_1(cp) * 5);
+		cp++;
+		PRINT;
+		ND_PRINT(".");
+		PRINT;
+		break;
+
+	case AUTH_MSG_APPL_REQUEST:
+		cp += 2;
+		ND_PRINT("v%u ", GET_U_1(cp));
+		cp++;
+		PRINT;
+		ND_PRINT(" (%u)", GET_U_1(cp));
+		cp++;
+		ND_PRINT(" (%u)", GET_U_1(cp));
+		break;
+
+	case AUTH_MSG_KDC_REPLY:
+		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
+			return;
+		cp += 10;	/* timestamp + n + exp + kvno */
+		len = KTOHSP(kp, cp);
+		ND_PRINT(" (%u)", len);
+		break;
+
+	case AUTH_MSG_ERR_REPLY:
+		if ((cp = krb4_print_hdr(ndo, cp)) == NULL)
+			return;
+		cp += 4;	  /* timestamp */
+		ND_PRINT(" %s ", tok2str(kerr2str, NULL, KTOHSP(kp, cp)));
+		cp += 4;
+		PRINT;
+		break;
+
+	default:
+		ND_PRINT("(unknown)");
+		break;
+	}
+
+	return;
+trunc:
+	nd_print_trunc(ndo);
+}
+
+void
+krb_print(netdissect_options *ndo,
+          const u_char *dat)
+{
+	const struct krb *kp;
+
+	ndo->ndo_protocol = "krb";
+	kp = (const struct krb *)dat;
+
+	if (dat >= ndo->ndo_snapend) {
+		nd_print_trunc(ndo);
+		return;
+	}
+
+	switch (GET_U_1(kp->pvno)) {
+
+	case 1:
+	case 2:
+	case 3:
+		ND_PRINT(" v%u", GET_U_1(kp->pvno));
+		break;
+
+	case 4:
+		ND_PRINT(" v%u", GET_U_1(kp->pvno));
+		krb4_print(ndo, (const u_char *)kp);
+		break;
+
+	case 106:
+	case 107:
+		ND_PRINT(" v5");
+		/* Decode ASN.1 here "someday" */
+		break;
+	}
+}