/*
 * 3. Validate
 */
static bool
authdes_validate(AUTH *auth, struct opaque_auth *rverf)
{
	/* LINTED pointer alignment */
	struct ad_private *ad = AUTH_PRIVATE(auth);
	struct authdes_verf verf;
	int status;
	uint32_t *ixdr;
	des_block buf;

	if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT)
		return (false);

	/* LINTED pointer alignment */
	ixdr = (uint32_t *) rverf->oa_base;
	buf.key.high = (uint32_t) *ixdr++;
	buf.key.low = (uint32_t) *ixdr++;
	verf.adv_int_u = (uint32_t) *ixdr++;

	/*
	 * Decrypt the timestamp
	 */
	status =
	    ecb_crypt((char *)&auth->ah_key, (char *)&buf,
		      (u_int) sizeof(des_block), DES_DECRYPT | DES_HW);

	if (DES_FAILED(status)) {
		__warnx(TIRPC_DEBUG_FLAG_AUTH,
			"authdes_validate: DES decryption failure");
		return (false);
	}

	/*
	 * xdr the decrypted timestamp
	 */
	/* LINTED pointer alignment */
	ixdr = (uint32_t *) buf.c;
	verf.adv_timestamp.tv_sec = IXDR_GET_INT32(ixdr) + 1;
	verf.adv_timestamp.tv_usec = IXDR_GET_INT32(ixdr);

	/*
	 * validate
	 */
	if (bcmp
	    ((char *)&ad->ad_timestamp, (char *)&verf.adv_timestamp,
	     sizeof(struct timeval)) != 0) {
		__warnx(TIRPC_DEBUG_FLAG_AUTH,
			"authdes_validate: verifier mismatch");
		return (false);
	}

	/*
	 * We have a nickname now, let's use it
	 */
	ad->ad_nickname = verf.adv_nickname;
	ad->ad_cred.adc_namekind = ADN_NICKNAME;
	return (true);
}

static void
authunix_destroy(AUTH *auth)
{
	struct audata *au = AUTH_PRIVATE(auth);

	assert(auth != NULL);

	mem_free(au, sizeof(*au));
}

/*
 * Function: auth_gssapi_marhsall
 *
 * Purpose: Marshall RPC credentials and verifier onto xdr stream.
 *
 * Arguments:
 *
 * 	auth		(r/w) AUTH structure for client
 * 	xdrs		(r/w) XDR stream to marshall to
 *
 * Returns: boolean indicating success/failure
 *
 * Effects:
 * 
 * The pre-serialized credentials in cred_buf are serialized.  If the
 * context is established, the sealed sequence number is serialized as
 * the verifier.  If the context is not established, an empty verifier
 * is serialized.  The sequence number is *not* incremented, because
 * this function is called multiple times if retransmission is required.
 * 
 * If this took all the header fields as arguments, it could sign
 * them.
 */
static bool_t auth_gssapi_marshall(
     AUTH *auth,
     XDR *xdrs)
{
     OM_uint32 minor_stat;
     gss_buffer_desc out_buf;
     uint32_t seq_num;
     
     if (AUTH_PRIVATE(auth)->established == TRUE)  {
	  PRINTF(("gssapi_marshall: starting\n"));
	  
	  seq_num = AUTH_PRIVATE(auth)->seq_num + 1;
	  
	  PRINTF(("gssapi_marshall: sending seq_num %d\n", seq_num));
	  
	  if (auth_gssapi_seal_seq(AUTH_PRIVATE(auth)->context, seq_num,
				   &out_buf) == FALSE) {
	       PRINTF(("gssapi_marhshall: seal failed\n"));
	  }
	  
	  auth->ah_verf.oa_base = out_buf.value;
	  auth->ah_verf.oa_length = out_buf.length;
	  
	  if (! xdr_opaque_auth(xdrs, &auth->ah_cred) ||
	      ! xdr_opaque_auth(xdrs, &auth->ah_verf)) {
	       (void) gss_release_buffer(&minor_stat, &out_buf);
	       return FALSE;
	  }
	  (void) gss_release_buffer(&minor_stat, &out_buf);
     } else {
	  PRINTF(("gssapi_marshall: not established, sending null verf\n"));
	  
	  auth->ah_verf.oa_base = NULL;
	  auth->ah_verf.oa_length = 0;
	  
	  if (! xdr_opaque_auth(xdrs, &auth->ah_cred) ||
	      ! xdr_opaque_auth(xdrs, &auth->ah_verf)) {
	       return FALSE;
	  }
     }
     
     return TRUE;
}

static bool
authunix_marshal(AUTH *auth, XDR *xdrs)
{
	struct audata *au = AUTH_PRIVATE(auth);

	assert(auth != NULL);
	assert(xdrs != NULL);

	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
}

/*
 * 5. Destroy
 */
static void
authdes_destroy (AUTH *auth)
{
  struct ad_private *ad = AUTH_PRIVATE (auth);

  FREE (ad->ad_fullname, ad->ad_fullnamelen + 1);
  FREE (ad->ad_servername, ad->ad_servernamelen + 1);
  FREE (ad, sizeof (struct ad_private));
  FREE (auth, sizeof (AUTH));
}

/*
 * Function: marshall_new_creds
 *
 * Purpose: (pre-)serialize auth_msg and client_handle fields of
 * auth_gssapi_creds into auth->cred_buf
 *
 * Arguments:
 *
 * 	auth		(r/w) the AUTH structure to modify
 * 	auth_msg	(r) the auth_msg field to serialize
 * 	client_handle	(r) the client_handle field to serialize, or
 * 			NULL
 *
 * Returns: TRUE if successful, FALSE if not
 *
 * Requires: auth must point to a valid GSS-API auth structure, auth_msg
 * must be TRUE or FALSE, client_handle must be a gss_buffer_t with a valid
 * value and length field or NULL.
 * 
 * Effects: auth->ah_cred is set to the serialized auth_gssapi_creds
 * version 2 structure (stored in the cred_buf field of private data)
 * containing version, auth_msg and client_handle.
 * auth->ah_cred.oa_flavor is set to AUTH_GSSAPI.  If cliend_handle is
 * NULL, it is treated as if it had a length of 0 and a value of NULL.
 *
 * Modifies: auth
 */
static bool_t marshall_new_creds(
     AUTH *auth,
     bool_t auth_msg,
     gss_buffer_t client_handle)
{
     auth_gssapi_creds creds;
     XDR xdrs;
     
     PRINTF(("marshall_new_creds: starting\n"));

     creds.version = 2;
     
     creds.auth_msg = auth_msg;
     if (client_handle)
	  GSS_COPY_BUFFER(creds.client_handle, *client_handle)
     else {
	  creds.client_handle.length = 0;
	  creds.client_handle.value = NULL;
     }
     
     xdrmem_create(&xdrs, (caddr_t) AUTH_PRIVATE(auth)->cred_buf,
		   MAX_AUTH_BYTES, XDR_ENCODE);
     if (! xdr_authgssapi_creds(&xdrs, &creds)) {
	  PRINTF(("marshall_new_creds: failed encoding auth_gssapi_creds\n"));
	  XDR_DESTROY(&xdrs);
	  return FALSE;
     }
     AUTH_PRIVATE(auth)->cred_len = xdr_getpos(&xdrs);
     XDR_DESTROY(&xdrs);
     
     PRINTF(("marshall_new_creds: auth_gssapi_creds is %d bytes\n",
	     AUTH_PRIVATE(auth)->cred_len));
     
     auth->ah_cred.oa_flavor = AUTH_GSSAPI;
     auth->ah_cred.oa_base = (char *) AUTH_PRIVATE(auth)->cred_buf;
     auth->ah_cred.oa_length = AUTH_PRIVATE(auth)->cred_len;
     
     PRINTF(("marshall_new_creds: succeeding\n"));
     
     return TRUE;
}

static bool_t
authgss_validate(AUTH *auth, struct opaque_auth *verf)
{
	struct rpc_gss_data	*gd;
	u_int			 num, qop_state;
	gss_buffer_desc		 signbuf, checksum;
	OM_uint32		 maj_stat, min_stat;

	log_debug("in authgss_validate()");

	gd = AUTH_PRIVATE(auth);

	if (gd->established == FALSE) {
		/* would like to do this only on NULL rpc --
		 * gc->established is good enough.
		 * save the on the wire verifier to validate last
		 * INIT phase packet after decode if the major
		 * status is GSS_S_COMPLETE
		 */
		if ((gd->gc_wire_verf.value =
				mem_alloc(verf->oa_length)) == NULL) {
			fprintf(stderr, "gss_validate: out of memory\n");
			return (FALSE);
		}
		memcpy(gd->gc_wire_verf.value, verf->oa_base, verf->oa_length);
		gd->gc_wire_verf.length = verf->oa_length;
		return (TRUE);
  	}

	if (gd->gc.gc_proc == RPCSEC_GSS_INIT ||
	    gd->gc.gc_proc == RPCSEC_GSS_CONTINUE_INIT) {
		num = htonl(gd->win);
	}
	else num = htonl(gd->gc.gc_seq);

	signbuf.value = #
	signbuf.length = sizeof(num);

	checksum.value = verf->oa_base;
	checksum.length = verf->oa_length;

	maj_stat = gss_verify_mic(&min_stat, gd->ctx, &signbuf,
				  &checksum, &qop_state);
	if (maj_stat != GSS_S_COMPLETE || qop_state != gd->sec.qop) {
		log_status("gss_verify_mic", maj_stat, min_stat);
		if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
			gd->established = FALSE;
			authgss_destroy_context(auth);
		}
		return (FALSE);
	}
	return (TRUE);
}

/*
 * 3. Validate
 */
static bool_t
authdes_validate (AUTH *auth, struct opaque_auth *rverf)
{
  struct ad_private *ad = AUTH_PRIVATE (auth);
  struct authdes_verf verf;
  int status;
  register uint32_t *ixdr;

  if (rverf->oa_length != (2 + 1) * BYTES_PER_XDR_UNIT)
    return FALSE;

  ixdr = (uint32_t *) rverf->oa_base;
  verf.adv_xtimestamp.key.high = *ixdr++;
  verf.adv_xtimestamp.key.low = *ixdr++;
  verf.adv_int_u = *ixdr++;	/* nickname not XDR'd ! */

  /*
   * Decrypt the timestamp
   */
  status = ecb_crypt ((char *) &auth->ah_key, (char *) &verf.adv_xtimestamp,
		      sizeof (des_block), DES_DECRYPT | DES_HW);

  if (DES_FAILED (status))
    {
      debug ("authdes_validate: DES decryption failure");
      return FALSE;
    }

  /*
   * xdr the decrypted timestamp
   */
  ixdr = (uint32_t *) verf.adv_xtimestamp.c;
  verf.adv_timestamp.tv_sec = IXDR_GET_U_INT32 (ixdr) + 1;
  verf.adv_timestamp.tv_usec = IXDR_GET_U_INT32 (ixdr);

  /*
   * validate
   */
  if (memcmp ((char *) &ad->ad_timestamp, (char *) &verf.adv_timestamp,
	      sizeof (struct rpc_timeval)) != 0)
    {
      debug ("authdes_validate: verifier mismatch\n");
      return FALSE;
    }

  /*
   * We have a nickname now, let's use it
   */
  ad->ad_nickname = verf.adv_nickname;
  ad->ad_cred.adc_namekind = ADN_NICKNAME;
  return TRUE;
}

static bool_t
rpc_gss_validate(AUTH *auth, struct opaque_auth *verf)
{
	struct rpc_gss_data	*gd;
	gss_qop_t		qop_state;
	uint32_t		num;
	gss_buffer_desc		signbuf, checksum;
	OM_uint32		maj_stat, min_stat;

	log_debug("in rpc_gss_validate()");
	
	gd = AUTH_PRIVATE(auth);

	if (gd->gd_state == RPCSEC_GSS_CONTEXT) {
		/*
		 * Save the on the wire verifier to validate last INIT
		 * phase packet after decode if the major status is
		 * GSS_S_COMPLETE.
		 */
		if (gd->gd_verf.value)
			xdr_free((xdrproc_t) xdr_gss_buffer_desc,
			    (char *) &gd->gd_verf);
		gd->gd_verf.value = mem_alloc(verf->oa_length);
		if (gd->gd_verf.value == NULL) {
			fprintf(stderr, "gss_validate: out of memory\n");
			_rpc_gss_set_error(RPC_GSS_ER_SYSTEMERROR, ENOMEM);
			return (FALSE);
		}
		memcpy(gd->gd_verf.value, verf->oa_base, verf->oa_length);
		gd->gd_verf.length = verf->oa_length;
		return (TRUE);
	}

	num = htonl(gd->gd_cred.gc_seq);
	signbuf.value = #
	signbuf.length = sizeof(num);
	
	checksum.value = verf->oa_base;
	checksum.length = verf->oa_length;
	
	maj_stat = gss_verify_mic(&min_stat, gd->gd_ctx, &signbuf,
	    &checksum, &qop_state);
	if (maj_stat != GSS_S_COMPLETE || qop_state != gd->gd_qop) {
		log_status("gss_verify_mic", gd->gd_mech, maj_stat, min_stat);
		if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
			rpc_gss_destroy_context(auth, TRUE);
		}
		_rpc_gss_set_error(RPC_GSS_ER_SYSTEMERROR, EPERM);
		return (FALSE);
	}
	return (TRUE);
}

/*
 * Function: auth_gssapi_unwrap
 *
 * Purpose: read encrypted arguments from xdrs, decrypt, and
 * deserialize with xdr_func into xdr_ptr.
 *
 * Effects: See design doc, section XXX.
 */
static bool_t auth_gssapi_unwrap(
     AUTH *auth,
     XDR *in_xdrs,
     bool_t (*xdr_func)(),
     caddr_t xdr_ptr)
{
     OM_uint32 gssstat, minor_stat;
     
     if (! AUTH_PRIVATE(auth)->established) {
	  PRINTF(("gssapi_unwrap: context not established, noop\n"));
	  return (*xdr_func)(in_xdrs, xdr_ptr);
     } else if (! auth_gssapi_unwrap_data(&gssstat, &minor_stat,
					  AUTH_PRIVATE(auth)->context,
					  AUTH_PRIVATE(auth)->seq_num,
					  in_xdrs, xdr_func, xdr_ptr)) {
	  if (gssstat != GSS_S_COMPLETE)
	       AUTH_GSSAPI_DISPLAY_STATUS(("decrypting function arguments",
					   gssstat, minor_stat));
	  return FALSE;
     } else
	  return TRUE;
}

/*
 * Function: auth_gssapi_refresh
 *
 * Purpose: Attempts to resyncrhonize the sequence number.
 *
 * Effects:
 * 
 * When the server receives a properly authenticated RPC call, it
 * increments the sequence number it is expecting from the client.
 * But if the server's response is lost for any reason, the client
 * can't know whether the server ever received it, assumes it didn't,
 * and does *not* increment its sequence number.  Thus, the client's
 * next call will fail with AUTH_REJECTEDCRED because the server will
 * think it is a replay attack.
 *
 * When an AUTH_REJECTEDCRED error arrives, this function attempts to
 * resyncrhonize by incrementing the client's sequence number and
 * returning TRUE.  If any other error arrives, it returns FALSE.
 */
static bool_t auth_gssapi_refresh(
     AUTH *auth,
     struct rpc_msg *msg)
{
     if (msg->rm_reply.rp_rjct.rj_stat == AUTH_ERROR &&
	 msg->rm_reply.rp_rjct.rj_why == AUTH_REJECTEDVERF) {
	  PRINTF(("gssapi_refresh: rejected verifier, incrementing\n"));
	  AUTH_PRIVATE(auth)->seq_num++;
	  return TRUE;
     } else {
	  PRINTF(("gssapi_refresh: failing\n"));
	  return FALSE;
     }
}

/*
 * Function: auth_gssapi_validate
 *
 * Purpose: Validate RPC response verifier from server.
 *
 * Effects: See design document, section XXX.
 */
static bool_t auth_gssapi_validate(
     AUTH *auth,
     struct opaque_auth *verf)
{
     gss_buffer_desc in_buf;
     uint32_t seq_num;
     
     if (AUTH_PRIVATE(auth)->established == FALSE) {
	  PRINTF(("gssapi_validate: not established, noop\n"));
	  return TRUE;
     }
     
     PRINTF(("gssapi_validate: starting\n"));
     
     in_buf.length = verf->oa_length;
     in_buf.value = verf->oa_base;
     if (auth_gssapi_unseal_seq(AUTH_PRIVATE(auth)->context, &in_buf,
				&seq_num) == FALSE) {
	  PRINTF(("gssapi_validate: failed unsealing verifier\n"));
	  return FALSE;
     }
     
     /* we sent seq_num+1, so we should get back seq_num+2 */
     if (AUTH_PRIVATE(auth)->seq_num+2 != seq_num) {
	  PRINTF(("gssapi_validate: expecting seq_num %d, got %d (%#x)\n",
		  AUTH_PRIVATE(auth)->seq_num + 2, seq_num, seq_num));
	  return FALSE;
     }
     PRINTF(("gssapi_validate: seq_num %d okay\n", seq_num));
     
     /* +1 for successful transmission, +1 for successful validation */
     AUTH_PRIVATE(auth)->seq_num += 2;
     
     PRINTF(("gssapi_validate: succeeding\n"));
     
     return TRUE;
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */
static void
marshal_new_auth(AUTH *auth)
{
	XDR		xdr_stream;
	XDR	*xdrs = &xdr_stream;
	struct audata *au = AUTH_PRIVATE(auth);

	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
		perror("auth_none.c - Fatal marshalling problem");
	} else {
		au->au_mpos = XDR_GETPOS(xdrs);
	}
	XDR_DESTROY(xdrs);
}

bool_t
authgss_unwrap(AUTH *auth, XDR *xdrs, xdrproc_t xdr_func, caddr_t xdr_ptr)
{
	struct rpc_gss_data	*gd;

	log_debug("in authgss_unwrap()");

	gd = AUTH_PRIVATE(auth);

	if (!gd->established || gd->sec.svc == RPCSEC_GSS_SVC_NONE) {
		return ((*xdr_func)(xdrs, xdr_ptr));
	}
	return (xdr_rpc_gss_data(xdrs, xdr_func, xdr_ptr,
				 gd->ctx, gd->sec.qop,
				 gd->sec.svc, gd->gc.gc_seq));
}

bool_t
authgss_service(AUTH *auth, int svc)
{
	struct rpc_gss_data	*gd;

	log_debug("in authgss_service()");

	if (!auth)
		return(FALSE);
	gd = AUTH_PRIVATE(auth);
	if (!gd || !gd->established)
		return (FALSE);
	gd->sec.svc = svc;
	gd->gc.gc_svc = svc;
	return (TRUE);
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */
static void
marshal_new_auth(AUTH *auth)
{
	XDR		xdr_stream;
	XDR	*xdrs = &xdr_stream;
	struct audata *au = AUTH_PRIVATE(auth);

	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
		/* XXX nothing we can do */
	} else {
		au->au_mpos = XDR_GETPOS(xdrs);
	}
	XDR_DESTROY(xdrs);
}

static void
authunix_destroy(AUTH *auth)
{
	struct audata *au = AUTH_PRIVATE(auth);

	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);

	if (au->au_shcred.oa_base != NULL)
		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);

	mem_free(auth->ah_private, sizeof(struct audata));

	if (auth->ah_verf.oa_base != NULL)
		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);

	mem_free((caddr_t)auth, sizeof(*auth));
}

/*
 * 5. Destroy
 */
static void
authdes_destroy(AUTH *auth)
{
/* LINTED pointer alignment */
	struct ad_private *ad = AUTH_PRIVATE(auth);

	FREE(ad->ad_fullname, ad->ad_fullnamelen + 1);
	FREE(ad->ad_servername, ad->ad_servernamelen + 1);
	if (ad->ad_timehost)
		FREE(ad->ad_timehost, strlen(ad->ad_timehost) + 1);
	if (ad->ad_netid)
		FREE(ad->ad_netid, strlen(ad->ad_netid) + 1);
	if (ad->ad_uaddr)
		FREE(ad->ad_uaddr, strlen(ad->ad_uaddr) + 1);
	FREE(ad, sizeof(struct ad_private));
	FREE(auth, sizeof(AUTH));
}

bool_t
__rpc_gss_unwrap(AUTH *auth, XDR *xdrs, xdrproc_t xdr_func, void *xdr_ptr)
{
	struct rpc_gss_data	*gd;

	log_debug("in rpc_gss_unwrap()");
	
	gd = AUTH_PRIVATE(auth);
	
	if (gd->gd_state != RPCSEC_GSS_ESTABLISHED ||
	    gd->gd_cred.gc_svc == rpc_gss_svc_none) {
		return (xdr_func(xdrs, xdr_ptr));
	}
	return (xdr_rpc_gss_unwrap_data(xdrs, xdr_func, xdr_ptr,
		gd->gd_ctx, gd->gd_qop, gd->gd_cred.gc_svc,
		gd->gd_cred.gc_seq));
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */
static void
marshal_new_auth(AUTH *auth)
{
	XDR xdrs[1];
	struct audata *au = AUTH_PRIVATE(auth);

	assert(auth != NULL);

	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
	if ((!xdr_opaque_auth_encode(xdrs, &(auth->ah_cred)))
	    || (!xdr_opaque_auth_encode(xdrs, &(auth->ah_verf))))
		__warnx(TIRPC_DEBUG_FLAG_AUTH,
			"auth_none.c - Fatal marshalling " "problem");
	else
		au->au_mpos = XDR_GETPOS(xdrs);
	XDR_DESTROY(xdrs);
}