diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_generic_token.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_generic_token.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_generic_token.c b/net/sunrpc/auth_gss/gss_generic_token.c new file mode 100644 index 00000000..c586e92b --- /dev/null +++ b/net/sunrpc/auth_gss/gss_generic_token.c @@ -0,0 +1,234 @@ +/* + * 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/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 data + +For the purposes of this abstraction, the token "header" consists of +the sequence tag and length octets, the mech OID DER encoding, and the +first two inner bytes, which indicate the token type. The token +"body" consists of everything else. + +*/ + +static int +der_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 void +der_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 int +der_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 */ + +int +g_token_size(struct xdr_netobj *mech, unsigned int body_size) +{ + /* set body_size to sequence contents size */ + body_size += 2 + (int) mech->len; /* NEED overflow check */ + return 1 + der_length_size(body_size) + body_size; +} + +EXPORT_SYMBOL_GPL(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 */ + +void +g_make_token_header(struct xdr_netobj *mech, int body_size, unsigned char **buf) +{ + *(*buf)++ = 0x60; + der_write_length(buf, 2 + mech->len + body_size); + *(*buf)++ = 0x06; + *(*buf)++ = (unsigned char) mech->len; + TWRITE_STR(*buf, mech->data, ((int) mech->len)); +} + +EXPORT_SYMBOL_GPL(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. + */ +u32 +g_verify_token_header(struct xdr_netobj *mech, int *body_size, + unsigned char **buf_in, 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_GPL(g_verify_token_header); + |