commit 695df6532ec717e5571e1ddc2c88a8c968603c5a
from: Alexander Barton <alex@barton.de>
date: Fri Jun 01 22:24:53 2012 UTC

IDENT reply: only allow alphanumeric characters in user name

Only alphanumeric characters are allowed in the user name, so ignore
all IDENT replies that would violate this rule and use the one supplied
by the USER command.

commit - 6680b536c4da7dc27e11490fe098e98cb0393fa2
commit + 695df6532ec717e5571e1ddc2c88a8c968603c5a
blob - b6e628092633fb68a34b8175e383b195033d9b0f
blob + 4d778719a2c8623c60570e9c839877595b38e0a2
--- src/ngircd/conn.c
+++ src/ngircd/conn.c
@@ -2174,6 +2174,7 @@ cb_Read_Resolver_Result( int r_fd, UNUSED short events
 	char *identptr;
 #ifdef IDENTAUTH
 	char readbuf[HOST_LEN + 2 + CLIENT_USER_LEN];
+	char *ptr;
 #else
 	char readbuf[HOST_LEN + 1];
 #endif
@@ -2226,11 +2227,30 @@ cb_Read_Resolver_Result( int r_fd, UNUSED short events
 #ifdef IDENTAUTH
 		++identptr;
 		if (*identptr) {
-			Log(LOG_INFO, "IDENT lookup for connection %d: \"%s\".", i, identptr);
-			Client_SetUser(c, identptr, true);
-			if (Conf_NoticeAuth)
+			ptr = identptr;
+			while (*ptr) {
+				if ((*ptr < '0' || *ptr > '9') &&
+				    (*ptr < 'A' || *ptr > 'Z') &&
+				    (*ptr < 'a' || *ptr > 'z'))
+					break;
+				ptr++;
+			}
+			if (*ptr) {
+				/* Erroneous IDENT reply */
+				Log(LOG_NOTICE,
+				    "Got invalid IDENT reply for connection %d! Ignored.",
+				    i);
+			} else {
+				Log(LOG_INFO,
+				    "IDENT lookup for connection %d: \"%s\".",
+				    i, identptr);
+				Client_SetUser(c, identptr, true);
+			}
+			if (Conf_NoticeAuth) {
 				(void)Conn_WriteStr(i,
-					"NOTICE AUTH :*** Got ident response");
+					"NOTICE AUTH :*** Got %sident response",
+					*ptr == NULL ? "" : "invalid ");
+			}
 		} else {
 			Log(LOG_INFO, "IDENT lookup for connection %d: no result.", i);
 			if (Conf_NoticeAuth && Conf_Ident)