60643d379b
(Including all changes for FreeBSD - importing the original eBones distribution would be too complex at this stage, since I don't have access to Piero's CVS.) (If you want to include eBones in your system, don't forget to include MAKE_EBONES in /etc/make.conf.) (This stuff is now also suppable from braae.ru.ac.za.) Bones originally from MIT SIPB. Original port to FreeBSD 1.x by Piero Serini. Moved to FreeBSD 2.0 by Doug Rabson and Geoff Rehmet. Nice bug fixes from Doug Rabson.
205 lines
6.2 KiB
C
205 lines
6.2 KiB
C
/*
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* Copyright 1986, 1987, 1988 by the Massachusetts Institute
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* of Technology.
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* For copying and distribution information, please see the file
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* <Copyright.MIT>.
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*
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* This routine dissects a a Kerberos 'private msg', decrypting it,
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* checking its integrity, and returning a pointer to the application
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* data contained and its length.
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*
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* Returns 0 (RD_AP_OK) for success or an error code (RD_AP_...). If
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* the return value is RD_AP_TIME, then either the times are too far
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* out of synch, OR the packet was modified.
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*
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* Steve Miller Project Athena MIT/DEC
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*
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* from: rd_priv.c,v 4.14 89/04/28 11:59:42 jtkohl Exp $
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* $Id: rd_priv.c,v 1.2 1994/07/19 19:26:11 g89r4222 Exp $
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*/
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#ifndef lint
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static char rcsid[]=
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"$Id: rd_priv.c,v 1.2 1994/07/19 19:26:11 g89r4222 Exp $";
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#endif /* lint */
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/* system include files */
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#include <stdio.h>
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#include <errno.h>
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <sys/time.h>
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/* application include files */
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#include <des.h>
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#include <krb.h>
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#include <prot.h>
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#include "lsb_addr_comp.h"
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extern char *errmsg();
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extern int errno;
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extern int krb_debug;
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/* static storage */
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static u_long c_length;
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static int swap_bytes;
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static struct timeval local_time;
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static long delta_t;
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int private_msg_ver = KRB_PROT_VERSION;
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/*
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#ifdef NOENCRPYTION
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* krb_rd_priv() checks the integrity of an
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#else
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* krb_rd_priv() decrypts and checks the integrity of an
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#endif
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* AUTH_MSG_PRIVATE message. Given the message received, "in",
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* the length of that message, "in_length", the key "schedule"
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* and "key", and the network addresses of the
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* "sender" and "receiver" of the message, krb_rd_safe() returns
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* RD_AP_OK if the message is okay, otherwise some error code.
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*
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* The message data retrieved from "in" are returned in the structure
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* "m_data". The pointer to the application data
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* (m_data->app_data) refers back to the appropriate place in "in".
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*
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* See the file "mk_priv.c" for the format of the AUTH_MSG_PRIVATE
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* message. The structure containing the extracted message
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* information, MSG_DAT, is defined in "krb.h".
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*/
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long krb_rd_priv(in,in_length,schedule,key,sender,receiver,m_data)
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u_char *in; /* pointer to the msg received */
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u_long in_length; /* length of "in" msg */
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Key_schedule schedule; /* precomputed key schedule */
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C_Block key; /* encryption key for seed and ivec */
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struct sockaddr_in *sender;
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struct sockaddr_in *receiver;
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MSG_DAT *m_data; /*various input/output data from msg */
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{
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register u_char *p,*q;
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static u_long src_addr; /* Can't send structs since no
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* guarantees on size */
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if (gettimeofday(&local_time,(struct timezone *)0))
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return -1;
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p = in; /* beginning of message */
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swap_bytes = 0;
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if (*p++ != KRB_PROT_VERSION && *(p-1) != 3)
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return RD_AP_VERSION;
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private_msg_ver = *(p-1);
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if (((*p) & ~1) != AUTH_MSG_PRIVATE)
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return RD_AP_MSG_TYPE;
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if ((*p++ & 1) != HOST_BYTE_ORDER)
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swap_bytes++;
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/* get cipher length */
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bcopy((char *)p,(char *)&c_length,sizeof(c_length));
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if (swap_bytes)
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swap_u_long(c_length);
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p += sizeof(c_length);
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/* check for rational length so we don't go comatose */
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if (VERSION_SZ + MSG_TYPE_SZ + c_length > in_length)
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return RD_AP_MODIFIED;
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q = p; /* mark start of encrypted stuff */
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#ifndef NOENCRYPTION
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pcbc_encrypt((C_Block *)q,(C_Block *)q,(long)c_length,schedule,key,DECRYPT);
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#endif
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/* safely get application data length */
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bcopy((char *) p,(char *)&(m_data->app_length),
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sizeof(m_data->app_length));
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if (swap_bytes)
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swap_u_long(m_data->app_length);
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p += sizeof(m_data->app_length); /* skip over */
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if (m_data->app_length + sizeof(c_length) + sizeof(in_length) +
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sizeof(m_data->time_sec) + sizeof(m_data->time_5ms) +
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sizeof(src_addr) + VERSION_SZ + MSG_TYPE_SZ
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> in_length)
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return RD_AP_MODIFIED;
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#ifndef NOENCRYPTION
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/* we're now at the decrypted application data */
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#endif
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m_data->app_data = p;
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p += m_data->app_length;
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/* safely get time_5ms */
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bcopy((char *) p, (char *)&(m_data->time_5ms),
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sizeof(m_data->time_5ms));
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/* don't need to swap-- one byte for now */
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p += sizeof(m_data->time_5ms);
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/* safely get src address */
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bcopy((char *) p,(char *)&src_addr,sizeof(src_addr));
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/* don't swap, net order always */
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p += sizeof(src_addr);
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if (src_addr != (u_long) sender->sin_addr.s_addr)
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return RD_AP_MODIFIED;
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/* safely get time_sec */
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bcopy((char *) p, (char *)&(m_data->time_sec),
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sizeof(m_data->time_sec));
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if (swap_bytes) swap_u_long(m_data->time_sec);
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p += sizeof(m_data->time_sec);
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/* check direction bit is the sign bit */
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/* For compatibility with broken old code, compares are done in VAX
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byte order (LSBFIRST) */
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if (lsb_net_ulong_less(sender->sin_addr.s_addr,
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receiver->sin_addr.s_addr)==-1)
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/* src < recv */
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m_data->time_sec = - m_data->time_sec;
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else if (lsb_net_ulong_less(sender->sin_addr.s_addr,
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receiver->sin_addr.s_addr)==0)
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if (lsb_net_ushort_less(sender->sin_port,receiver->sin_port)==-1)
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/* src < recv */
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m_data->time_sec = - m_data->time_sec;
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/*
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* all that for one tiny bit!
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* Heaven help those that talk to themselves.
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*/
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/* check the time integrity of the msg */
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delta_t = abs((int)((long) local_time.tv_sec
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- m_data->time_sec));
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if (delta_t > CLOCK_SKEW)
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return RD_AP_TIME;
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if (krb_debug)
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printf("\ndelta_t = %d",delta_t);
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/*
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* caller must check timestamps for proper order and
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* replays, since server might have multiple clients
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* each with its own timestamps and we don't assume
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* tightly synchronized clocks.
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*/
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#ifdef notdef
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bcopy((char *) p,(char *)&cksum,sizeof(cksum));
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if (swap_bytes) swap_u_long(cksum)
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/*
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* calculate the checksum of the length, sequence,
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* and input data, on the sending byte order!!
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*/
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calc_cksum = quad_cksum(q,NULL,p-q,0,key);
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if (krb_debug)
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printf("\ncalc_cksum = %u, received cksum = %u",
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calc_cksum, cksum);
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if (cksum != calc_cksum)
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return RD_AP_MODIFIED;
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#endif
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return RD_AP_OK; /* OK == 0 */
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}
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