/* * lib/krb4/mk_err.c * * Copyright 1985, 1986, 1987, 1988, 2000 by the Massachusetts * Institute of Technology. All Rights Reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. Furthermore if you modify this software you must label * your software as modified software and not distribute it in such a * fashion that it might be confused with the original M.I.T. software. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. */ #include "krb.h" #include "prot.h" #include <string.h> /* * This routine creates a general purpose error reply message. It * doesn't use KTEXT because application protocol may have long * messages, and may want this part of buffer contiguous to other * stuff. * * The error reply is built in "p", using the error code "e" and * error text "e_string" given. The length of the error reply is * returned. * * The error reply is in the following format: * * unsigned char KRB_PROT_VERSION protocol version no. * unsigned char AUTH_MSG_APPL_ERR message type * (least significant * bit of above) HOST_BYTE_ORDER local byte order * 4 bytes e given error code * string e_string given error text */ long KRB5_CALLCONV krb_mk_err(p, e, e_string) u_char *p; /* Where to build error packet */ KRB4_32 e; /* Error code */ char *e_string; /* Text of error */ { u_char *start; size_t e_len; e_len = strlen(e_string) + 1; /* Just return the buffer length if p is NULL, because writing to the * buffer would be a bad idea. Note that this feature is a change from * previous versions, and can therefore only be used safely in this * source tree, where we know this function supports it. */ if (p == NULL) { return 1 + 1 + 4 + e_len; } start = p; /* Create fixed part of packet */ *p++ = KRB_PROT_VERSION; *p++ = AUTH_MSG_APPL_ERR; /* Add the basic info */ KRB4_PUT32BE(p, e); memcpy(p, e_string, e_len); /* err text */ p += e_len; /* And return the length */ return p - start; }