Fix for CAN-2004-0175, based on Markus Friedl's fix for OpenSSH scp.

diff -up krb5-1.7/src/appl/bsd/krcp.c krb5-1.7/src/appl/bsd/krcp.c
--- krb5-1.7/src/appl/bsd/krcp.c	2009-06-04 14:27:20.000000000 -0400
+++ krb5-1.7/src/appl/bsd/krcp.c	2009-06-04 14:27:20.000000000 -0400
@@ -1038,6 +1038,10 @@ void sink(argc, argv)
 	  size = size * 10 + (*cp++ - '0');
 	if (*cp++ != ' ')
 	  SCREWUP("size not delimited");
+	if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
+	  error("error: unexpected filename: %s", cp);
+	  exit(1);
+	}
 	if (targisdir) {
           if(strlen(targ) + strlen(cp) + 2 >= sizeof(nambuf))
 	    SCREWUP("target name too long");
@@ -1051,6 +1055,8 @@ void sink(argc, argv)
 	nambuf[sizeof(nambuf) - 1] = '\0';
 	exists = stat(nambuf, &stb) == 0;
 	if (cmdbuf[0] == 'D') {
+	    if (!iamrecursive)
+		SCREWUP("received directory without -r");
 	    if (exists) {
 		if ((stb.st_mode&S_IFMT) != S_IFDIR) {
 		    errno = ENOTDIR;