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) 2000-2008 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/jiffies.h> 63 #include <linux/sunrpc/gss_krb5.h> 64 #include <linux/random.h> 65 #include <linux/crypto.h> 66 67 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 68 # define RPCDBG_FACILITY RPCDBG_AUTH 69 #endif 70 71 DEFINE_SPINLOCK(krb5_seq_lock); 72 73 static void * 74 setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token) 75 { 76 u16 *ptr; 77 void *krb5_hdr; 78 int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength; 79 80 token->len = g_token_size(&ctx->mech_used, body_size); 81 82 ptr = (u16 *)token->data; 83 g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr); 84 85 /* ptr now at start of header described in rfc 1964, section 1.2.1: */ 86 krb5_hdr = ptr; 87 *ptr++ = KG_TOK_MIC_MSG; 88 /* 89 * signalg is stored as if it were converted from LE to host endian, even 90 * though it's an opaque pair of bytes according to the RFC. 91 */ 92 *ptr++ = (__force u16)cpu_to_le16(ctx->gk5e->signalg); 93 *ptr++ = SEAL_ALG_NONE; 94 *ptr = 0xffff; 95 96 return krb5_hdr; 97 } 98 99 static void * 100 setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token) 101 { 102 u16 *ptr; 103 void *krb5_hdr; 104 u8 *p, flags = 0x00; 105 106 if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) 107 flags |= 0x01; 108 if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) 109 flags |= 0x04; 110 111 /* Per rfc 4121, sec 4.2.6.1, there is no header, 112 * just start the token */ 113 krb5_hdr = ptr = (u16 *)token->data; 114 115 *ptr++ = KG2_TOK_MIC; 116 p = (u8 *)ptr; 117 *p++ = flags; 118 *p++ = 0xff; 119 ptr = (u16 *)p; 120 *ptr++ = 0xffff; 121 *ptr = 0xffff; 122 123 token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength; 124 return krb5_hdr; 125 } 126 127 static u32 128 gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text, 129 struct xdr_netobj *token) 130 { 131 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 132 struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), 133 .data = cksumdata}; 134 void *ptr; 135 s32 now; 136 u32 seq_send; 137 u8 *cksumkey; 138 139 dprintk("RPC: %s\n", __func__); 140 BUG_ON(ctx == NULL); 141 142 now = get_seconds(); 143 144 ptr = setup_token(ctx, token); 145 146 if (ctx->gk5e->keyed_cksum) 147 cksumkey = ctx->cksum; 148 else 149 cksumkey = NULL; 150 151 if (make_checksum(ctx, ptr, 8, text, 0, cksumkey, 152 KG_USAGE_SIGN, &md5cksum)) 153 return GSS_S_FAILURE; 154 155 memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len); 156 157 spin_lock(&krb5_seq_lock); 158 seq_send = ctx->seq_send++; 159 spin_unlock(&krb5_seq_lock); 160 161 if (krb5_make_seq_num(ctx, ctx->seq, ctx->initiate ? 0 : 0xff, 162 seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)) 163 return GSS_S_FAILURE; 164 165 return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 166 } 167 168 static u32 169 gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text, 170 struct xdr_netobj *token) 171 { 172 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 173 struct xdr_netobj cksumobj = { .len = sizeof(cksumdata), 174 .data = cksumdata}; 175 void *krb5_hdr; 176 s32 now; 177 u64 seq_send; 178 u8 *cksumkey; 179 unsigned int cksum_usage; 180 181 dprintk("RPC: %s\n", __func__); 182 183 krb5_hdr = setup_token_v2(ctx, token); 184 185 /* Set up the sequence number. Now 64-bits in clear 186 * text and w/o direction indicator */ 187 spin_lock(&krb5_seq_lock); 188 seq_send = ctx->seq_send64++; 189 spin_unlock(&krb5_seq_lock); 190 *((__be64 *)(krb5_hdr + 8)) = cpu_to_be64(seq_send); 191 192 if (ctx->initiate) { 193 cksumkey = ctx->initiator_sign; 194 cksum_usage = KG_USAGE_INITIATOR_SIGN; 195 } else { 196 cksumkey = ctx->acceptor_sign; 197 cksum_usage = KG_USAGE_ACCEPTOR_SIGN; 198 } 199 200 if (make_checksum_v2(ctx, krb5_hdr, GSS_KRB5_TOK_HDR_LEN, 201 text, 0, cksumkey, cksum_usage, &cksumobj)) 202 return GSS_S_FAILURE; 203 204 memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len); 205 206 now = get_seconds(); 207 208 return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 209 } 210 211 u32 212 gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text, 213 struct xdr_netobj *token) 214 { 215 struct krb5_ctx *ctx = gss_ctx->internal_ctx_id; 216 217 switch (ctx->enctype) { 218 default: 219 BUG(); 220 case ENCTYPE_DES_CBC_RAW: 221 case ENCTYPE_DES3_CBC_RAW: 222 case ENCTYPE_ARCFOUR_HMAC: 223 return gss_get_mic_v1(ctx, text, token); 224 case ENCTYPE_AES128_CTS_HMAC_SHA1_96: 225 case ENCTYPE_AES256_CTS_HMAC_SHA1_96: 226 return gss_get_mic_v2(ctx, text, token); 227 } 228 } 229 230