/* *  linux/net/sunrpc/gss_generic_token.c * *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/generic/util_token.c * *  Copyright (c) 2000 The Regents of the University of Michigan. *  All rights reserved. * *  Andy Adamson   <andros@umich.edu> *//* * Copyright 1993 by OpenVision Technologies, Inc. *  * Permission to use, copy, modify, distribute, and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appears in all copies and * that both that copyright notice and this permission notice appear in * supporting documentation, and that the name of OpenVision not be used * in advertising or publicity pertaining to distribution of the software * without specific, written prior permission. OpenVision makes no * representations about the suitability of this software for any * purpose.  It is provided "as is" without express or implied warranty. *  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */#include <linux/types.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/sunrpc/sched.h>#include <linux/sunrpc/gss_asn1.h>#ifdef RPC_DEBUG# define RPCDBG_FACILITY        RPCDBG_AUTH#endif/* TWRITE_STR from gssapiP_generic.h */#define TWRITE_STR(ptr, str, len) \	memcpy((ptr), (char *) (str), (len)); \	(ptr) += (len);/* XXXX this code currently makes the assumption that a mech oid will   never be longer than 127 bytes.  This assumption is not inherent in   the interfaces, so the code can be fixed if the OSI namespace   balloons unexpectedly. *//* Each token looks like this:0x60				tag for APPLICATION 0, SEQUENCE					(constructed, definite-length)	<length>		possible multiple bytes, need to parse/generate	0x06			tag for OBJECT IDENTIFIER		<moid_length>	compile-time constant string (assume 1 byte)		<moid_bytes>	compile-time constant string	<inner_bytes>		the ANY containing the application token					bytes 0,1 are the token type					bytes 2,n are the token dataFor the purposes of this abstraction, the token "header" consists ofthe sequence tag and length octets, the mech OID DER encoding, and thefirst two inner bytes, which indicate the token type.  The token"body" consists of everything else.*/static intder_length_size( int length){	if (length < (1<<7))		return(1);	else if (length < (1<<8))		return(2);#if (SIZEOF_INT == 2)	else		return(3);#else	else if (length < (1<<16))		return(3);	else if (length < (1<<24))		return(4);	else		return(5);#endif}static voidder_write_length(unsigned char **buf, int length){	if (length < (1<<7)) {		*(*buf)++ = (unsigned char) length;	} else {		*(*buf)++ = (unsigned char) (der_length_size(length)+127);#if (SIZEOF_INT > 2)		if (length >= (1<<24))			*(*buf)++ = (unsigned char) (length>>24);		if (length >= (1<<16))			*(*buf)++ = (unsigned char) ((length>>16)&0xff);#endif		if (length >= (1<<8))			*(*buf)++ = (unsigned char) ((length>>8)&0xff);		*(*buf)++ = (unsigned char) (length&0xff);	}}/* returns decoded length, or < 0 on failure.  Advances buf and   decrements bufsize */static intder_read_length(unsigned char **buf, int *bufsize){	unsigned char sf;	int ret;	if (*bufsize < 1)		return(-1);	sf = *(*buf)++;	(*bufsize)--;	if (sf & 0x80) {		if ((sf &= 0x7f) > ((*bufsize)-1))			return(-1);		if (sf > SIZEOF_INT)			return (-1);		ret = 0;		for (; sf; sf--) {			ret = (ret<<8) + (*(*buf)++);			(*bufsize)--;		}	} else {		ret = sf;	}	return(ret);}/* returns the length of a token, given the mech oid and the body size */intg_token_size(struct xdr_netobj *mech, unsigned int body_size){	/* set body_size to sequence contents size */	body_size += 4 + (int) mech->len;         /* NEED overflow check */	return(1 + der_length_size(body_size) + body_size);}EXPORT_SYMBOL(g_token_size);/* fills in a buffer with the token header.  The buffer is assumed to   be the right size.  buf is advanced past the token header */voidg_make_token_header(struct xdr_netobj *mech, int body_size, unsigned char **buf){	*(*buf)++ = 0x60;	der_write_length(buf, 4 + mech->len + body_size);	*(*buf)++ = 0x06;	*(*buf)++ = (unsigned char) mech->len;	TWRITE_STR(*buf, mech->data, ((int) mech->len));}EXPORT_SYMBOL(g_make_token_header);/* * Given a buffer containing a token, reads and verifies the token, * leaving buf advanced past the token header, and setting body_size * to the number of remaining bytes.  Returns 0 on success, * G_BAD_TOK_HEADER for a variety of errors, and G_WRONG_MECH if the * mechanism in the token does not match the mech argument.  buf and * *body_size are left unmodified on error. */u32g_verify_token_header(struct xdr_netobj *mech, int *body_size,		      unsigned char **buf_in, int tok_type, int toksize){	unsigned char *buf = *buf_in;	int seqsize;	struct xdr_netobj toid;	int ret = 0;	if ((toksize-=1) < 0)		return(G_BAD_TOK_HEADER);	if (*buf++ != 0x60)		return(G_BAD_TOK_HEADER);	if ((seqsize = der_read_length(&buf, &toksize)) < 0)		return(G_BAD_TOK_HEADER);	if (seqsize != toksize)		return(G_BAD_TOK_HEADER);	if ((toksize-=1) < 0)		return(G_BAD_TOK_HEADER);	if (*buf++ != 0x06)		return(G_BAD_TOK_HEADER); 	if ((toksize-=1) < 0)		return(G_BAD_TOK_HEADER);	toid.len = *buf++;	if ((toksize-=toid.len) < 0)		return(G_BAD_TOK_HEADER);	toid.data = buf;	buf+=toid.len;	if (! g_OID_equal(&toid, mech)) 		ret = G_WRONG_MECH;    /* G_WRONG_MECH is not returned immediately because it's more important      to return G_BAD_TOK_HEADER if the token header is in fact bad */	if ((toksize-=2) < 0)		return(G_BAD_TOK_HEADER);	if (ret)		return(ret);	if (!ret) {		*buf_in = buf;		*body_size = toksize;	}	return(ret);}EXPORT_SYMBOL(g_verify_token_header);/* Given a buffer containing a token, returns a copy of the mech oid in * the parameter mech. */u32g_get_mech_oid(struct xdr_netobj *mech, struct xdr_netobj * in_buf){	unsigned char *buf = in_buf->data;	int len = in_buf->len;	int ret=0;	int seqsize;	if ((len-=1) < 0)		return(G_BAD_TOK_HEADER);	if (*buf++ != 0x60)		return(G_BAD_TOK_HEADER);	if ((seqsize = der_read_length(&buf, &len)) < 0)		return(G_BAD_TOK_HEADER);	if ((len-=1) < 0)		return(G_BAD_TOK_HEADER);	if (*buf++ != 0x06)		return(G_BAD_TOK_HEADER);	if ((len-=1) < 0)		return(G_BAD_TOK_HEADER);	mech->len = *buf++;	if ((len-=mech->len) < 0)		return(G_BAD_TOK_HEADER);	if (!(mech->data = kmalloc(mech->len, GFP_KERNEL))) 		return(G_BUFFER_ALLOC);	memcpy(mech->data, buf, mech->len);	return ret;}