Backout unrelated changes in last commit

1 files changed, 30 insertions, 24 deletions

diff --git a/libexec/telnetd/state.c b/libexec/telnetd/state.c
index c6cb0d09649..d20f49eb80c 100644
--- a/libexec/telnetd/state.c
+++ b/libexec/telnetd/state.c
@@ -895,38 +895,44 @@ int env_ovalue = -1;
 #endif	/* ENV_HACK */
 
 /*
- * Environment variables that are safe to let through.
- * Anything else will simply be dropped.
+ * variables not to let through.
+ * if name ends in =, it is complete variable name
+ * if it does not end in =, all variables starting with this name
+ * should be dropped.
  */
-char *goodenv_table[] = {
-	"TERM",
-	"DISPLAY",
-	"USER",
-	"LOGNAME",
-	"POSIXLY_CORRECT",
-	NULL
+char *badenv_table[] = {
+        "IFS=",
+        "LD_",
+        "_RLD_",
+        "SHLIB_PATH=",
+        "LIBPATH=",
+        "KRB",
+        "ENV=",
+        "BASH_ENV=",
+        NULL,
 };
 
+/* envvarok(char*) */
 /* check that variable is safe to pass to login or shell */
-int
-envvarok(varp, valp)
+static int
+envvarok(varp)
         char *varp;
-        char *valp;
 {
         int i;
+        int len;
 
         if (strchr(varp, '='))
                 return (0);
-
-	for (i = 0; goodenv_table[i]; i++) {
-		if (strcmp(goodenv_table[i], varp) != 0)
-			continue;
-		/* disallow variables with slashes or ones that are too long */
-		if (strchr(valp, '/') || strlen(valp) >= 0x100)
-			return (0);
-		return (1);
-	}
-	return (0);
+        for (i = 0; badenv_table[i]; i++) {
+                len = strlen(badenv_table[i]);
+                if (badenv_table[i][len-1] == '=' &&
+                    !strncmp(badenv_table[i], varp, len-1) &&
+                    varp[len-2] == '\0')
+                        return (0);
+                if (!strncmp(badenv_table[i], varp, len-1))
+                        return (0);
+        }
+        return (1);
 }
 
 /*
@@ -1219,7 +1225,7 @@ suboption(void)
 	    case NEW_ENV_VAR:
 	    case ENV_USERVAR:
 		*cp = '\0';
-		if (envvarok(varp, valp)) {
+		if(envvarok(varp)) {
 		    if (valp)
 			esetenv(varp, valp, 1);
 		    else
@@ -1240,7 +1246,7 @@ suboption(void)
 	    }
 	}
 	*cp = '\0';
-	if (envvarok(varp, valp)) {
+	if(envvarok(varp)) {
 	    if (valp)
 		esetenv(varp, valp, 1);
 	    else