Update the code for the DHCP authentication option to match RFC 3118,

and update the URL for the DHCP parameter value assignments; support a
code of 90 for DHCP authentication, as that's what RFC 3118 specifies.

Show symbolic values for some of the fields in the DHCP authentication
option, and base the decision on whether to dissect the authentication
data as HMAC-MD5 data on whether that's what the protocol and algorithm
field specified.  Show the replay detection value as a 64-bit number
only if it's specified to be a monotonically-increasing counter;
otherwise, just show it as bytes.

svn path=/trunk/; revision=4116

1 files changed, 100 insertions, 20 deletions

diff --git a/packet-bootp.c b/packet-bootp.c
index f46362efa6..992abf57fd 100644
--- a/packet-bootp.c
+++ b/packet-bootp.c
@@ -2,7 +2,7 @@
  * Routines for BOOTP/DHCP packet disassembly
  * Gilbert Ramirez <gram@xiexie.org>
  *
- * $Id: packet-bootp.c,v 1.55 2001/10/29 21:56:47 guy Exp $
+ * $Id: packet-bootp.c,v 1.56 2001/10/31 08:43:09 guy Exp $
  *
  * The information used comes from:
  * RFC  951: Bootstrap Protocol
@@ -11,8 +11,9 @@
  * RFC 2132: DHCP Options and BOOTP Vendor Extensions
  * RFC 2489: Procedure for Defining New DHCP Options
  * RFC 3046: DHCP Relay Agent Information Option
+ * RFC 3118: Authentication for DHCP Messages
  * BOOTP and DHCP Parameters
- *     http://www.isi.edu/in-notes/iana/assignments/bootp-dhcp-parameters
+ *     http://www.iana.org/assignments/bootp-dhcp-parameters
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -113,6 +114,16 @@ get_dhcp_type(guint8 byte)
 	return opt53_text[i];
 }
 
+/* DHCP Authentication protocols */
+#define AUTHEN_PROTO_CONFIG_TOKEN	0
+#define AUTHEN_PROTO_DELAYED_AUTHEN	1
+
+/* DHCP Authentication algorithms for delayed authentication */
+#define AUTHEN_DELAYED_ALGO_HMAC_MD5	1
+
+/* DHCP Authentication Replay Detection Methods */
+#define AUTHEN_RDM_MONOTONIC_COUNTER	0x00
+
 /* Returns the number of bytes consumed by this option. */
 static int
 bootp_option(tvbuff_t *tvb, proto_tree *bp_tree, int voff, int eoff,
@@ -128,8 +139,9 @@ bootp_option(tvbuff_t *tvb, proto_tree *bp_tree, int voff, int eoff,
 	u_long			time_secs;
 	proto_tree		*v_tree;
 	proto_item		*vti;
-	const char              *md5_ptr;
-	char                    md5_str[50];
+	guint8			protocol;
+	guint8			algorithm;
+	guint8			rdm;
 
 	static const value_string nbnt_vals[] = {
 	    {0x1,   "B-node" },
@@ -138,6 +150,19 @@ bootp_option(tvbuff_t *tvb, proto_tree *bp_tree, int voff, int eoff,
 	    {0x8,   "H-node" },
 	    {0,     NULL     } };
 
+	static const value_string authen_protocol_vals[] = {
+	    {AUTHEN_PROTO_CONFIG_TOKEN,   "configuration token" },
+	    {AUTHEN_PROTO_DELAYED_AUTHEN, "delayed authentication" },
+	    {0,                           NULL     } };
+
+	static const value_string authen_da_algo_vals[] = {
+	    {AUTHEN_DELAYED_ALGO_HMAC_MD5, "HMAC_MD5" },
+	    {0,                            NULL     } };
+
+	static const value_string authen_rdm_vals[] = {
+	    {AUTHEN_RDM_MONOTONIC_COUNTER, "Monotonically-increasing counter" },
+	    {0,                            NULL     } };
+
 	static struct opt_info opt[] = {
 		/*   0 */ { "Padding",								none },
 		/*   1 */ { "Subnet Mask",							ipv4 },
@@ -229,7 +254,7 @@ bootp_option(tvbuff_t *tvb, proto_tree *bp_tree, int voff, int eoff,
 		/*  87 */ { "Novell Directory Services Context",	opaque },
 		/*  88 */ { "IEEE 1003.1 POSIX Timezone",			opaque },
 		/*  89 */ { "Fully Qualified Domain Name",			opaque },
-		/*  90 */ { "Authentication",						opaque },
+		/*  90 */ { "Authentication",				special },
 		/*  91 */ { "Vines TCP/IP Server Option",			opaque },
 		/*  92 */ { "Server Selection Option",				opaque },
 		/*  93 */ { "Client System Architecture",			opaque },
@@ -577,26 +602,81 @@ bootp_option(tvbuff_t *tvb, proto_tree *bp_tree, int voff, int eoff,
 		}
 		break;
 
-	case 210:	/* DHCP Authentication */
+	case 90:	/* DHCP Authentication */
+	case 210:	/* Was this used for authentication at one time? */
 		vti = proto_tree_add_text(bp_tree, tvb, voff,
 			vlen + 2, "Option %d: %s", code, text);
 		v_tree = proto_item_add_subtree(vti, ett_bootp_option);
-		proto_tree_add_text(v_tree, tvb, voff+2, 1, "Protocol: %d", 
-				    tvb_get_guint8(tvb, voff+2));
-		proto_tree_add_text(v_tree, tvb, voff+3, 1, "Algorithm: %d", 
-				    tvb_get_guint8(tvb, voff+3));
-		proto_tree_add_text(v_tree, tvb, voff+4, 1, "Replay Detection Method: %d", 
-				    tvb_get_guint8(tvb, voff+4));
-		proto_tree_add_text(v_tree, tvb, voff+5, 8, "Replay Detection Value: %s", 
+
+		protocol = tvb_get_guint8(tvb, voff+2);
+		proto_tree_add_text(v_tree, tvb, voff+2, 1, "Protocol: %s (%u)", 
+				    val_to_str(protocol, authen_protocol_vals, "Unknown"),
+				    protocol);
+
+		algorithm = tvb_get_guint8(tvb, voff+3);
+		switch (protocol) {
+
+		case AUTHEN_PROTO_DELAYED_AUTHEN:
+			proto_tree_add_text(v_tree, tvb, voff+3, 1,
+				    "Algorithm: %s (%u)",
+				    val_to_str(algorithm, authen_da_algo_vals, "Unknown"),
+				    algorithm);
+			break;
+
+		default:
+			proto_tree_add_text(v_tree, tvb, voff+3, 1,
+				    "Algorithm: %u", algorithm);
+			break;
+		}
+
+		rdm = tvb_get_guint8(tvb, voff+4);
+		proto_tree_add_text(v_tree, tvb, voff+4, 1,
+				    "Replay Detection Method: %s (%u)",
+				    val_to_str(rdm, authen_rdm_vals, "Unknown"),
+				    rdm);
+
+		switch (rdm) {
+
+		case AUTHEN_RDM_MONOTONIC_COUNTER:
+			proto_tree_add_text(v_tree, tvb, voff+5, 8,
+				    "Replay Detection Value: %s", 
 				    u64toh(tvb_get_ptr(tvb, voff+5, 8)));
-		if (vlen > 11) {
-		    proto_tree_add_text(v_tree, tvb, voff+13, 4, "Secret ID: %0X", 
+			break;
+
+		default:
+			proto_tree_add_text(v_tree, tvb, voff+5, 8,
+				    "Replay Detection Value: %s", 
+				    tvb_bytes_to_str(tvb, voff+5, 8));
+			break;
+		}
+
+		switch (protocol) {
+
+		case AUTHEN_PROTO_DELAYED_AUTHEN:
+			switch (algorithm) {
+
+			case AUTHEN_DELAYED_ALGO_HMAC_MD5:
+				proto_tree_add_text(v_tree, tvb, voff+13, 4,
+					"Secret ID: 0x%08x", 
 					tvb_get_ntohl(tvb, voff+13));
-		    md5_ptr = tvb_get_ptr(tvb, voff+17, 16);
-		    for (i=0; i<16; i++)
-			sprintf(&(md5_str[i*3]), "%02X ", (guint8) md5_ptr[i]);
-		    md5_str[48] = 0;
-		    proto_tree_add_text(v_tree, tvb, voff+17, 16, "HMAC MD5 Hash: %s", md5_str);
+				proto_tree_add_text(v_tree, tvb, voff+17, 16,
+					"HMAC MD5 Hash: %s",
+					tvb_bytes_to_str(tvb, voff+17, 16));
+				break;
+
+			default:
+				proto_tree_add_text(v_tree, tvb, voff+13, vlen-11,
+					"Authentication Information: %s",
+					tvb_bytes_to_str(tvb, voff+17, vlen-11));
+				break;
+			}
+			break;
+
+		default:
+			proto_tree_add_text(v_tree, tvb, voff+13, vlen-11,
+				"Authentication Information: %s",
+				tvb_bytes_to_str(tvb, voff+17, vlen-11));
+			break;
 		}
 		break;