diff options
Diffstat (limited to 'eBones/lib/libkrb/mk_safe.c')
| -rw-r--r-- | eBones/lib/libkrb/mk_safe.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/eBones/lib/libkrb/mk_safe.c b/eBones/lib/libkrb/mk_safe.c new file mode 100644 index 0000000..567004b --- /dev/null +++ b/eBones/lib/libkrb/mk_safe.c @@ -0,0 +1,168 @@ +/* + * Copyright 1986, 1987, 1988 by the Massachusetts Institute + * of Technology. + * For copying and distribution information, please see the file + * <Copyright.MIT>. + * + * This routine constructs a Kerberos 'safe msg', i.e. authenticated + * using a private session key to seed a checksum. Msg is NOT + * encrypted. + * + * Note-- bcopy is used to avoid alignment problems on IBM RT + * + * Returns either <0 ===> error, or resulting size of message + * + * Steve Miller Project Athena MIT/DEC + * + * from: mk_safe.c,v 4.12 89/03/22 14:50:49 jtkohl Exp $ + * $Id: mk_safe.c,v 1.2 1994/07/19 19:25:59 g89r4222 Exp $ + */ + +#ifndef lint +static char rcsid[] = +"$Id: mk_safe.c,v 1.2 1994/07/19 19:25:59 g89r4222 Exp $"; +#endif /* lint */ + +/* system include files */ +#include <stdio.h> +#include <errno.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <sys/time.h> + +/* application include files */ +#include <des.h> +#include <krb.h> +#include <prot.h> +#include "lsb_addr_comp.h" + +extern char *errmsg(); +extern int errno; +extern int krb_debug; + +/* static storage */ + +static u_long cksum; +static C_Block big_cksum[2]; +static struct timeval msg_time; +static u_char msg_time_5ms; +static long msg_time_sec; + +/* + * krb_mk_safe() constructs an AUTH_MSG_SAFE message. It takes some + * user data "in" of "length" bytes and creates a packet in "out" + * consisting of the user data, a timestamp, and the sender's network + * address, followed by a checksum computed on the above, using the + * given "key". The length of the resulting packet is returned. + * + * The "out" packet consists of: + * + * Size Variable Field + * ---- -------- ----- + * + * 1 byte KRB_PROT_VERSION protocol version number + * 1 byte AUTH_MSG_SAFE | message type plus local + * HOST_BYTE_ORDER byte order in low bit + * + * ===================== begin checksum ================================ + * + * 4 bytes length length of user data + * length in user data + * 1 byte msg_time_5ms timestamp milliseconds + * 4 bytes sender->sin.addr.s_addr sender's IP address + * + * 4 bytes msg_time_sec or timestamp seconds with + * -msg_time_sec direction in sign bit + * + * ======================= end checksum ================================ + * + * 16 bytes big_cksum quadratic checksum of + * above using "key" + */ + +long krb_mk_safe(in,out,length,key,sender,receiver) + u_char *in; /* application data */ + u_char *out; /* + * put msg here, leave room for header! + * breaks if in and out (header stuff) + * overlap + */ + u_long length; /* of in data */ + C_Block *key; /* encryption key for seed and ivec */ + struct sockaddr_in *sender; /* sender address */ + struct sockaddr_in *receiver; /* receiver address */ +{ + register u_char *p,*q; + + /* + * get the current time to use instead of a sequence #, since + * process lifetime may be shorter than the lifetime of a session + * key. + */ + if (gettimeofday(&msg_time,(struct timezone *)0)) { + return -1; + } + msg_time_sec = (long) msg_time.tv_sec; + msg_time_5ms = msg_time.tv_usec/5000; /* 5ms quanta */ + + p = out; + + *p++ = KRB_PROT_VERSION; + *p++ = AUTH_MSG_SAFE | HOST_BYTE_ORDER; + + q = p; /* start for checksum stuff */ + /* stuff input length */ + bcopy((char *)&length,(char *)p,sizeof(length)); + p += sizeof(length); + + /* make all the stuff contiguous for checksum */ + bcopy((char *)in,(char *)p,(int) length); + p += length; + + /* stuff time 5ms */ + bcopy((char *)&msg_time_5ms,(char *)p,sizeof(msg_time_5ms)); + p += sizeof(msg_time_5ms); + + /* stuff source address */ + bcopy((char *) &sender->sin_addr.s_addr,(char *)p, + sizeof(sender->sin_addr.s_addr)); + p += sizeof(sender->sin_addr.s_addr); + + /* + * direction bit is the sign bit of the timestamp. Ok until + * 2038?? + */ + /* For compatibility with broken old code, compares are done in VAX + byte order (LSBFIRST) */ + if (lsb_net_ulong_less(sender->sin_addr.s_addr, /* src < recv */ + receiver->sin_addr.s_addr)==-1) + msg_time_sec = -msg_time_sec; + else if (lsb_net_ulong_less(sender->sin_addr.s_addr, + receiver->sin_addr.s_addr)==0) + if (lsb_net_ushort_less(sender->sin_port,receiver->sin_port) == -1) + msg_time_sec = -msg_time_sec; + /* + * all that for one tiny bit! Heaven help those that talk to + * themselves. + */ + + /* stuff time sec */ + bcopy((char *)&msg_time_sec,(char *)p,sizeof(msg_time_sec)); + p += sizeof(msg_time_sec); + +#ifdef NOENCRYPTION + cksum = 0; + bzero(big_cksum, sizeof(big_cksum)); +#else + cksum=quad_cksum(q,big_cksum,p-q,2,key); +#endif + if (krb_debug) + printf("\ncksum = %u",cksum); + + /* stuff checksum */ + bcopy((char *)big_cksum,(char *)p,sizeof(big_cksum)); + p += sizeof(big_cksum); + + return ((long)(p - out)); /* resulting size */ + +} |
