1 /* 2 * linux/net/sunrpc/gss_krb5_seal.c 3 * 4 * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.c 5 * 6 * Copyright (c) 2000 The Regents of the University of Michigan. 7 * All rights reserved. 8 * 9 * Andy Adamson <andros@umich.edu> 10 * J. Bruce Fields <bfields@umich.edu> 11 */ 12 13 /* 14 * Copyright 1993 by OpenVision Technologies, Inc. 15 * 16 * Permission to use, copy, modify, distribute, and sell this software 17 * and its documentation for any purpose is hereby granted without fee, 18 * provided that the above copyright notice appears in all copies and 19 * that both that copyright notice and this permission notice appear in 20 * supporting documentation, and that the name of OpenVision not be used 21 * in advertising or publicity pertaining to distribution of the software 22 * without specific, written prior permission. OpenVision makes no 23 * representations about the suitability of this software for any 24 * purpose. It is provided "as is" without express or implied warranty. 25 * 26 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 27 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 28 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR 29 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF 30 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR 31 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 32 * PERFORMANCE OF THIS SOFTWARE. 33 */ 34 35 /* 36 * Copyright (C) 1998 by the FundsXpress, INC. 37 * 38 * All rights reserved. 39 * 40 * Export of this software from the United States of America may require 41 * a specific license from the United States Government. It is the 42 * responsibility of any person or organization contemplating export to 43 * obtain such a license before exporting. 44 * 45 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 46 * distribute this software and its documentation for any purpose and 47 * without fee is hereby granted, provided that the above copyright 48 * notice appear in all copies and that both that copyright notice and 49 * this permission notice appear in supporting documentation, and that 50 * the name of FundsXpress. not be used in advertising or publicity pertaining 51 * to distribution of the software without specific, written prior 52 * permission. FundsXpress makes no representations about the suitability of 53 * this software for any purpose. It is provided "as is" without express 54 * or implied warranty. 55 * 56 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 57 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 58 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 59 */ 60 61 #include <linux/types.h> 62 #include <linux/slab.h> 63 #include <linux/jiffies.h> 64 #include <linux/sunrpc/gss_krb5.h> 65 #include <linux/random.h> 66 #include <asm/scatterlist.h> 67 #include <linux/crypto.h> 68 69 #ifdef RPC_DEBUG 70 # define RPCDBG_FACILITY RPCDBG_AUTH 71 #endif 72 73 static inline int 74 gss_krb5_padding(int blocksize, int length) { 75 /* Most of the code is block-size independent but in practice we 76 * use only 8: */ 77 BUG_ON(blocksize != 8); 78 return 8 - (length & 7); 79 } 80 81 u32 82 krb5_make_token(struct krb5_ctx *ctx, int qop_req, 83 struct xdr_buf *text, struct xdr_netobj *token, 84 int toktype) 85 { 86 s32 checksum_type; 87 struct xdr_netobj md5cksum = {.len = 0, .data = NULL}; 88 int blocksize = 0, tmsglen; 89 unsigned char *ptr, *krb5_hdr, *msg_start; 90 s32 now; 91 92 dprintk("RPC: gss_krb5_seal\n"); 93 94 now = get_seconds(); 95 96 if (qop_req != 0) 97 goto out_err; 98 99 switch (ctx->signalg) { 100 case SGN_ALG_DES_MAC_MD5: 101 checksum_type = CKSUMTYPE_RSA_MD5; 102 break; 103 default: 104 dprintk("RPC: gss_krb5_seal: ctx->signalg %d not" 105 " supported\n", ctx->signalg); 106 goto out_err; 107 } 108 if (ctx->sealalg != SEAL_ALG_NONE && ctx->sealalg != SEAL_ALG_DES) { 109 dprintk("RPC: gss_krb5_seal: ctx->sealalg %d not supported\n", 110 ctx->sealalg); 111 goto out_err; 112 } 113 114 if (toktype == KG_TOK_WRAP_MSG) { 115 blocksize = crypto_tfm_alg_blocksize(ctx->enc); 116 tmsglen = blocksize + text->len 117 + gss_krb5_padding(blocksize, blocksize + text->len); 118 } else { 119 tmsglen = 0; 120 } 121 122 token->len = g_token_size(&ctx->mech_used, 22 + tmsglen); 123 124 ptr = token->data; 125 g_make_token_header(&ctx->mech_used, 22 + tmsglen, &ptr); 126 127 *ptr++ = (unsigned char) ((toktype>>8)&0xff); 128 *ptr++ = (unsigned char) (toktype&0xff); 129 130 /* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */ 131 krb5_hdr = ptr - 2; 132 msg_start = krb5_hdr + 24; 133 134 *(u16 *)(krb5_hdr + 2) = htons(ctx->signalg); 135 memset(krb5_hdr + 4, 0xff, 4); 136 if (toktype == KG_TOK_WRAP_MSG) 137 *(u16 *)(krb5_hdr + 4) = htons(ctx->sealalg); 138 139 if (toktype == KG_TOK_WRAP_MSG) { 140 /* XXX removing support for now */ 141 goto out_err; 142 } else { /* Sign only. */ 143 if (make_checksum(checksum_type, krb5_hdr, 8, text, 144 &md5cksum)) 145 goto out_err; 146 } 147 148 switch (ctx->signalg) { 149 case SGN_ALG_DES_MAC_MD5: 150 if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, 151 md5cksum.data, md5cksum.len)) 152 goto out_err; 153 memcpy(krb5_hdr + 16, 154 md5cksum.data + md5cksum.len - KRB5_CKSUM_LENGTH, 155 KRB5_CKSUM_LENGTH); 156 157 dprintk("RPC: make_seal_token: cksum data: \n"); 158 print_hexl((u32 *) (krb5_hdr + 16), KRB5_CKSUM_LENGTH, 0); 159 break; 160 default: 161 BUG(); 162 } 163 164 kfree(md5cksum.data); 165 166 if ((krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff, 167 ctx->seq_send, krb5_hdr + 16, krb5_hdr + 8))) 168 goto out_err; 169 170 ctx->seq_send++; 171 172 return ((ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE); 173 out_err: 174 if (md5cksum.data) kfree(md5cksum.data); 175 return GSS_S_FAILURE; 176 } 177