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 #include <linux/atomic.h> 67 68 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 69 # define RPCDBG_FACILITY RPCDBG_AUTH 70 #endif 71 72 static void * 73 setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token) 74 { 75 u16 *ptr; 76 void *krb5_hdr; 77 int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength; 78 79 token->len = g_token_size(&ctx->mech_used, body_size); 80 81 ptr = (u16 *)token->data; 82 g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr); 83 84 /* ptr now at start of header described in rfc 1964, section 1.2.1: */ 85 krb5_hdr = ptr; 86 *ptr++ = KG_TOK_MIC_MSG; 87 /* 88 * signalg is stored as if it were converted from LE to host endian, even 89 * though it's an opaque pair of bytes according to the RFC. 90 */ 91 *ptr++ = (__force u16)cpu_to_le16(ctx->gk5e->signalg); 92 *ptr++ = SEAL_ALG_NONE; 93 *ptr = 0xffff; 94 95 return krb5_hdr; 96 } 97 98 static void * 99 setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token) 100 { 101 u16 *ptr; 102 void *krb5_hdr; 103 u8 *p, flags = 0x00; 104 105 if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) 106 flags |= 0x01; 107 if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) 108 flags |= 0x04; 109 110 /* Per rfc 4121, sec 4.2.6.1, there is no header, 111 * just start the token */ 112 krb5_hdr = ptr = (u16 *)token->data; 113 114 *ptr++ = KG2_TOK_MIC; 115 p = (u8 *)ptr; 116 *p++ = flags; 117 *p++ = 0xff; 118 ptr = (u16 *)p; 119 *ptr++ = 0xffff; 120 *ptr = 0xffff; 121 122 token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength; 123 return krb5_hdr; 124 } 125 126 static u32 127 gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text, 128 struct xdr_netobj *token) 129 { 130 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 131 struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), 132 .data = cksumdata}; 133 void *ptr; 134 time64_t now; 135 u32 seq_send; 136 u8 *cksumkey; 137 138 dprintk("RPC: %s\n", __func__); 139 BUG_ON(ctx == NULL); 140 141 now = ktime_get_real_seconds(); 142 143 ptr = setup_token(ctx, token); 144 145 if (ctx->gk5e->keyed_cksum) 146 cksumkey = ctx->cksum; 147 else 148 cksumkey = NULL; 149 150 if (make_checksum(ctx, ptr, 8, text, 0, cksumkey, 151 KG_USAGE_SIGN, &md5cksum)) 152 return GSS_S_FAILURE; 153 154 memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len); 155 156 seq_send = atomic_fetch_inc(&ctx->seq_send); 157 158 if (krb5_make_seq_num(ctx, ctx->seq, ctx->initiate ? 0 : 0xff, 159 seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)) 160 return GSS_S_FAILURE; 161 162 return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 163 } 164 165 static u32 166 gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text, 167 struct xdr_netobj *token) 168 { 169 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 170 struct xdr_netobj cksumobj = { .len = sizeof(cksumdata), 171 .data = cksumdata}; 172 void *krb5_hdr; 173 time64_t now; 174 u8 *cksumkey; 175 unsigned int cksum_usage; 176 __be64 seq_send_be64; 177 178 dprintk("RPC: %s\n", __func__); 179 180 krb5_hdr = setup_token_v2(ctx, token); 181 182 /* Set up the sequence number. Now 64-bits in clear 183 * text and w/o direction indicator */ 184 seq_send_be64 = cpu_to_be64(atomic64_fetch_inc(&ctx->seq_send64)); 185 memcpy(krb5_hdr + 8, (char *) &seq_send_be64, 8); 186 187 if (ctx->initiate) { 188 cksumkey = ctx->initiator_sign; 189 cksum_usage = KG_USAGE_INITIATOR_SIGN; 190 } else { 191 cksumkey = ctx->acceptor_sign; 192 cksum_usage = KG_USAGE_ACCEPTOR_SIGN; 193 } 194 195 if (make_checksum_v2(ctx, krb5_hdr, GSS_KRB5_TOK_HDR_LEN, 196 text, 0, cksumkey, cksum_usage, &cksumobj)) 197 return GSS_S_FAILURE; 198 199 memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len); 200 201 now = ktime_get_real_seconds(); 202 203 return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 204 } 205 206 u32 207 gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text, 208 struct xdr_netobj *token) 209 { 210 struct krb5_ctx *ctx = gss_ctx->internal_ctx_id; 211 212 switch (ctx->enctype) { 213 default: 214 BUG(); 215 case ENCTYPE_DES_CBC_RAW: 216 case ENCTYPE_DES3_CBC_RAW: 217 case ENCTYPE_ARCFOUR_HMAC: 218 return gss_get_mic_v1(ctx, text, token); 219 case ENCTYPE_AES128_CTS_HMAC_SHA1_96: 220 case ENCTYPE_AES256_CTS_HMAC_SHA1_96: 221 return gss_get_mic_v2(ctx, text, token); 222 } 223 } 224