/* 
  Copyright (C) 1989 by the Massachusetts Institute of Technology

   Export of this software from the United States of America is assumed
   to 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.  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.

  */

/*
 * Kerberos administration server-side support functions
 */

/* 
kadm_ser_wrap.c
unwraps wrapped packets and calls the appropriate server subroutine
*/

#include "kadm_locl.h"

RCSID("$Id: kadm_ser_wrap.c,v 1.25 1999/09/16 20:41:41 assar Exp $");

/* GLOBAL */
Kadm_Server server_parm;

/* 
kadm_ser_init
set up the server_parm structure
*/
int
kadm_ser_init(int inter,	/* interactive or from file */
	      char *realm,
	      struct in_addr addr)
{
  struct hostent *hp;
  char hostname[MaxHostNameLen];

  init_kadm_err_tbl();
  init_krb_err_tbl();
  if (gethostname(hostname, sizeof(hostname)))
      return KADM_NO_HOSTNAME;

  strlcpy(server_parm.sname,
		  PWSERV_NAME,
		  sizeof(server_parm.sname));
  strlcpy(server_parm.sinst,
		  KRB_MASTER,
		  sizeof(server_parm.sinst));
  strlcpy(server_parm.krbrlm,
		  realm,
		  sizeof(server_parm.krbrlm));

  server_parm.admin_fd = -1;
  /* setting up the addrs */
  memset(&server_parm.admin_addr,0, sizeof(server_parm.admin_addr));

  server_parm.admin_addr.sin_port = k_getportbyname (KADM_SNAME,
						     "tcp",
						     htons(751));
  server_parm.admin_addr.sin_family = AF_INET;
  if ((hp = gethostbyname(hostname)) == NULL)
      return KADM_NO_HOSTNAME;
  server_parm.admin_addr.sin_addr = addr;
				/* setting up the database */
  if (kdb_get_master_key((inter==1), &server_parm.master_key,
			 server_parm.master_key_schedule) != 0)
    return KADM_NO_MAST;
  if ((server_parm.master_key_version =
       kdb_verify_master_key(&server_parm.master_key,
			     server_parm.master_key_schedule,stderr))<0)
      return KADM_NO_VERI;
  return KADM_SUCCESS;
}

/*
 *
 */

static void
errpkt(u_char *errdat, u_char **dat, int *dat_len, int code)
{
    free(*dat);			/* free up req */
    *dat_len = KADM_VERSIZE + 4;
    memcpy(errdat, KADM_ULOSE, KADM_VERSIZE);
    krb_put_int (code, errdat + KADM_VERSIZE, 4, 4);
    *dat = errdat;
}

/*
kadm_ser_in
unwrap the data stored in dat, process, and return it.
*/
int
kadm_ser_in(u_char **dat, int *dat_len, u_char *errdat)
{
    u_char *in_st;			/* pointer into the sent packet */
    int in_len,retc;			/* where in packet we are, for
					   returns */
    u_int32_t r_len;			/* length of the actual packet */
    KTEXT_ST authent;			/* the authenticator */
    AUTH_DAT ad;			/* who is this, klink */
    u_int32_t ncksum;			/* checksum of encrypted data */
    des_key_schedule sess_sched;	/* our schedule */
    MSG_DAT msg_st;
    u_char *retdat, *tmpdat;
    int retval, retlen;

    if (*dat_len < (KADM_VERSIZE + sizeof(u_int32_t))
	|| strncmp(KADM_VERSTR, (char *)*dat, KADM_VERSIZE) != 0) {
	errpkt(errdat, dat, dat_len, KADM_BAD_VER);
	return KADM_BAD_VER;
    }
    in_len = KADM_VERSIZE;
    /* get the length */
    if ((retc = stv_long(*dat, &r_len, in_len, *dat_len)) < 0 ||
	(r_len > *dat_len - KADM_VERSIZE - sizeof(u_int32_t))) {
	errpkt(errdat, dat, dat_len, KADM_LENGTH_ERROR);
	return KADM_LENGTH_ERROR;
    }
    
    in_len += retc;
    authent.length = *dat_len - r_len - KADM_VERSIZE - sizeof(u_int32_t);
    if (authent.length > MAX_KTXT_LEN) {
	errpkt(errdat, dat, dat_len, KADM_LENGTH_ERROR);
	return KADM_LENGTH_ERROR;
    }
    memcpy(authent.dat, (char *)(*dat) + in_len, authent.length);
    authent.mbz = 0;
    /* service key should be set before here */
    if ((retc = krb_rd_req(&authent, server_parm.sname, server_parm.sinst,
			  server_parm.recv_addr.sin_addr.s_addr, &ad, NULL)))
    {
	errpkt(errdat, dat, dat_len, retc + krb_err_base);
	return retc + krb_err_base;
    }

#define clr_cli_secrets() {memset(sess_sched, 0, sizeof(sess_sched)); memset(ad.session, 0,sizeof(ad.session));}

    in_st = *dat + *dat_len - r_len;
#ifdef NOENCRYPTION
    ncksum = 0;
#else
    ncksum = des_quad_cksum((des_cblock *)in_st, (des_cblock *)0, (long) r_len, 0, &ad.session);
#endif
    if (ncksum!=ad.checksum) {		/* yow, are we correct yet */
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, KADM_BAD_CHK);
	return KADM_BAD_CHK;
    }
#ifdef NOENCRYPTION
    memset(sess_sched, 0, sizeof(sess_sched));
#else
    des_key_sched(&ad.session, sess_sched);
#endif
    if ((retc = (int) krb_rd_priv(in_st, r_len, sess_sched, &ad.session, 
				 &server_parm.recv_addr,
				 &server_parm.admin_addr, &msg_st))) {
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, retc + krb_err_base);
	return retc + krb_err_base;
    }
    switch (msg_st.app_data[0]) {
    case CHANGE_PW:
	retval = kadm_ser_cpw(msg_st.app_data+1,(int) msg_st.app_length - 1,
			      &ad, &retdat, &retlen);
	break;
    case ADD_ENT:
	retval = kadm_ser_add(msg_st.app_data+1,(int) msg_st.app_length - 1,
			      &ad, &retdat, &retlen);
	break;
    case GET_ENT:
	retval = kadm_ser_get(msg_st.app_data+1,(int) msg_st.app_length - 1,
			      &ad, &retdat, &retlen);
	break;
    case MOD_ENT:
	retval = kadm_ser_mod(msg_st.app_data+1,(int) msg_st.app_length - 1,
			      &ad, &retdat, &retlen);
	break;
    case DEL_ENT:
	retval = kadm_ser_delete(msg_st.app_data + 1, msg_st.app_length - 1, 
				 &ad, &retdat, &retlen);
	break;
    default:
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, KADM_NO_OPCODE);
	return KADM_NO_OPCODE;
    }
    /* Now seal the response back into a priv msg */
    tmpdat = (u_char *) malloc(retlen + KADM_VERSIZE + 4);
    if (tmpdat == NULL) {
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, KADM_NOMEM);
	return KADM_NOMEM;
    }
    free(*dat);
    memcpy(tmpdat, KADM_VERSTR, KADM_VERSIZE);
    krb_put_int(retval, tmpdat + KADM_VERSIZE, 4, 4);
    if (retlen) {
        memcpy(tmpdat + KADM_VERSIZE + 4, retdat, retlen);
	free(retdat);
    }
    /* slop for mk_priv stuff */
    *dat = (u_char *) malloc(retlen + KADM_VERSIZE +
			     sizeof(u_int32_t) + 200);
    if (*dat == NULL) {
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, KADM_NOMEM);
	return KADM_NOMEM;
    }
    if ((*dat_len = krb_mk_priv(tmpdat, *dat,
				(u_int32_t) (retlen + KADM_VERSIZE +
					  sizeof(u_int32_t)),
				sess_sched,
				&ad.session, &server_parm.admin_addr,
				&server_parm.recv_addr)) < 0) {
	clr_cli_secrets();
	errpkt(errdat, dat, dat_len, KADM_NO_ENCRYPT);
	return KADM_NO_ENCRYPT;
    }
    clr_cli_secrets();
    return KADM_SUCCESS;
}