## 10_urlsnarf_escape.dpatch by Hilko Bengen <bengen@debian.org>

##

## DP: Escape user, vhost, uri, referer, agent strings in log (Closes: #372536).

--- dsniff-2.4b1+debian~/urlsnarf.c	2006-11-27 17:09:54.000000000 +0100

+++ dsniff-2.4b1+debian/urlsnarf.c	2006-11-27 17:08:41.000000000 +0100

@@ -84,6 +84,43 @@

 	return (tstr);

 }

+static char *

+escape_log_entry(char *string)

+{

+	char *out;

+	unsigned char *c, *o;

+	size_t len;

+

+	if (!string)

+		return NULL;

+

+	/* Determine needed length */

+	for (c = string, len = 0; *c; c++) {

+		if ((*c < 32) || (*c >= 128))

+			len += 4;

+		else if ((*c == '"') || (*c =='\\'))

+			len += 2;

+		else

+			len++;

+	}

+	out = malloc(len+1);

+	if (!out)

+		return NULL;

+	for (c = string, o = out; *c; c++, o++) {

+		if ((*c < 32) || (*c >= 128)) {

+			snprintf(o, 5, "\\x%02x", *c);

+			o += 3;

+		} else if ((*c == '"') || ((*c =='\\'))) {

+			*(o++) = '\\';

+			*o = *c;

+		} else {

+			*o = *c;

+		}

+	}

+	out[len]='\0';

+	return out;

+}

+

 static int

 process_http_request(struct tuple4 *addr, u_char *data, int len)

 {

@@ -142,18 +179,26 @@

 				buf_tok(NULL, NULL, i);

 			}

 		}

-		if (user == NULL)

-			user = "-";

-		if (vhost == NULL)

-			vhost = libnet_addr2name4(addr->daddr, Opt_dns);

-		if (referer == NULL)

-			referer = "-";

-		if (agent == NULL)

-			agent = "-";

-		

+		user = escape_log_entry(user);

+		vhost = escape_log_entry(vhost);

+		uri = escape_log_entry(uri);

+		referer = escape_log_entry(referer);

+		agent = escape_log_entry(agent);

+

 		printf("%s - %s [%s] \"%s http://%s%s\" - - \"%s\" \"%s\"\n",

 		       libnet_addr2name4(addr->saddr, Opt_dns),

-		       user, timestamp(), req, vhost, uri, referer, agent);

+		       (user?user:"-"),

+		       timestamp(), req, 

+		       (vhost?vhost:libnet_addr2name4(addr->daddr, Opt_dns)), 

+		       uri,

+		       (referer?referer:"-"),

+		       (agent?agent:"-"));

+

+		free(user);

+		free(vhost);

+		free(uri);

+		free(referer);

+		free(agent);

 	}

 	fflush(stdout);