1 /* 2 rpcsec_gss_prot.c 3 4 Copyright (c) 2000 The Regents of the University of Michigan. 5 All rights reserved. 6 7 Copyright (c) 2000 Dug Song <dugsong@UMICH.EDU>. 8 All rights reserved, all wrongs reversed. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in the 18 documentation and/or other materials provided with the distribution. 19 3. Neither the name of the University nor the names of its 20 contributors may be used to endorse or promote products derived 21 from this software without specific prior written permission. 22 23 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 24 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 25 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 26 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 30 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 35 $Id: authgss_prot.c,v 1.18 2000/09/01 04:14:03 dugsong Exp $ 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kobj.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/mutex.h> 48 49 #include <rpc/rpc.h> 50 #include <rpc/rpcsec_gss.h> 51 52 #include "rpcsec_gss_int.h" 53 54 #define MAX_GSS_SIZE 10240 /* XXX */ 55 56 #if 0 /* use the one from kgssapi */ 57 bool_t 58 xdr_gss_buffer_desc(XDR *xdrs, gss_buffer_desc *p) 59 { 60 char *val; 61 u_int len; 62 bool_t ret; 63 64 val = p->value; 65 len = p->length; 66 ret = xdr_bytes(xdrs, &val, &len, MAX_GSS_SIZE); 67 p->value = val; 68 p->length = len; 69 70 return (ret); 71 } 72 #endif 73 74 bool_t 75 xdr_rpc_gss_cred(XDR *xdrs, struct rpc_gss_cred *p) 76 { 77 enum_t proc, svc; 78 bool_t ret; 79 80 proc = p->gc_proc; 81 svc = p->gc_svc; 82 ret = (xdr_u_int(xdrs, &p->gc_version) && 83 xdr_enum(xdrs, &proc) && 84 xdr_u_int(xdrs, &p->gc_seq) && 85 xdr_enum(xdrs, &svc) && 86 xdr_gss_buffer_desc(xdrs, &p->gc_handle)); 87 p->gc_proc = proc; 88 p->gc_svc = svc; 89 90 return (ret); 91 } 92 93 bool_t 94 xdr_rpc_gss_init_res(XDR *xdrs, struct rpc_gss_init_res *p) 95 { 96 97 return (xdr_gss_buffer_desc(xdrs, &p->gr_handle) && 98 xdr_u_int(xdrs, &p->gr_major) && 99 xdr_u_int(xdrs, &p->gr_minor) && 100 xdr_u_int(xdrs, &p->gr_win) && 101 xdr_gss_buffer_desc(xdrs, &p->gr_token)); 102 } 103 104 static void 105 put_uint32(struct mbuf **mp, uint32_t v) 106 { 107 struct mbuf *m = *mp; 108 uint32_t n; 109 110 M_PREPEND(m, sizeof(uint32_t), M_WAITOK); 111 n = htonl(v); 112 bcopy(&n, mtod(m, uint32_t *), sizeof(uint32_t)); 113 *mp = m; 114 } 115 116 bool_t 117 xdr_rpc_gss_wrap_data(struct mbuf **argsp, 118 gss_ctx_id_t ctx, gss_qop_t qop, 119 rpc_gss_service_t svc, u_int seq) 120 { 121 struct mbuf *args, *mic; 122 OM_uint32 maj_stat, min_stat; 123 int conf_state; 124 u_int len; 125 static char zpad[4]; 126 127 args = *argsp; 128 129 /* 130 * Prepend the sequence number before calling gss_get_mic or gss_wrap. 131 */ 132 put_uint32(&args, seq); 133 len = m_length(args, NULL); 134 135 if (svc == rpc_gss_svc_integrity) { 136 /* Checksum rpc_gss_data_t. */ 137 maj_stat = gss_get_mic_mbuf(&min_stat, ctx, qop, args, &mic); 138 if (maj_stat != GSS_S_COMPLETE) { 139 rpc_gss_log_debug("gss_get_mic failed"); 140 m_freem(args); 141 return (FALSE); 142 } 143 144 /* 145 * Marshal databody_integ. Note that since args is 146 * already RPC encoded, there will be no padding. 147 */ 148 put_uint32(&args, len); 149 150 /* 151 * Marshal checksum. This is likely to need padding. 152 */ 153 len = m_length(mic, NULL); 154 put_uint32(&mic, len); 155 if (len != RNDUP(len)) { 156 m_append(mic, RNDUP(len) - len, zpad); 157 } 158 159 /* 160 * Concatenate databody_integ with checksum. 161 */ 162 m_cat(args, mic); 163 } else if (svc == rpc_gss_svc_privacy) { 164 /* Encrypt rpc_gss_data_t. */ 165 maj_stat = gss_wrap_mbuf(&min_stat, ctx, TRUE, qop, 166 &args, &conf_state); 167 if (maj_stat != GSS_S_COMPLETE) { 168 rpc_gss_log_status("gss_wrap", NULL, 169 maj_stat, min_stat); 170 return (FALSE); 171 } 172 173 /* 174 * Marshal databody_priv and deal with RPC padding. 175 */ 176 len = m_length(args, NULL); 177 put_uint32(&args, len); 178 if (len != RNDUP(len)) { 179 m_append(args, RNDUP(len) - len, zpad); 180 } 181 } 182 *argsp = args; 183 return (TRUE); 184 } 185 186 static uint32_t 187 get_uint32(struct mbuf **mp) 188 { 189 struct mbuf *m = *mp; 190 uint32_t n; 191 192 if (m->m_len < sizeof(uint32_t)) { 193 m = m_pullup(m, sizeof(uint32_t)); 194 if (!m) { 195 *mp = NULL; 196 return (0); 197 } 198 } 199 bcopy(mtod(m, uint32_t *), &n, sizeof(uint32_t)); 200 m_adj(m, sizeof(uint32_t)); 201 *mp = m; 202 return (ntohl(n)); 203 } 204 205 static void 206 m_trim(struct mbuf *m, int len) 207 { 208 struct mbuf *n; 209 int off; 210 211 n = m_getptr(m, len, &off); 212 if (n) { 213 n->m_len = off; 214 if (n->m_next) { 215 m_freem(n->m_next); 216 n->m_next = NULL; 217 } 218 } 219 } 220 221 bool_t 222 xdr_rpc_gss_unwrap_data(struct mbuf **resultsp, 223 gss_ctx_id_t ctx, gss_qop_t qop, 224 rpc_gss_service_t svc, u_int seq) 225 { 226 struct mbuf *results, *message, *mic; 227 uint32_t len, cklen; 228 OM_uint32 maj_stat, min_stat; 229 u_int seq_num, conf_state, qop_state; 230 231 results = *resultsp; 232 *resultsp = NULL; 233 234 message = NULL; 235 if (svc == rpc_gss_svc_integrity) { 236 /* 237 * Extract the seq+message part. Remember that there 238 * may be extra RPC padding in the checksum. The 239 * message part is RPC encoded already so no 240 * padding. 241 */ 242 len = get_uint32(&results); 243 message = results; 244 results = m_split(results, len, M_WAITOK); 245 if (!results) { 246 m_freem(message); 247 return (FALSE); 248 } 249 250 /* 251 * Extract the MIC and make it contiguous. 252 */ 253 cklen = get_uint32(&results); 254 KASSERT(cklen <= MHLEN, ("unexpected large GSS-API checksum")); 255 mic = results; 256 if (cklen > mic->m_len) 257 mic = m_pullup(mic, cklen); 258 if (cklen != RNDUP(cklen)) 259 m_trim(mic, cklen); 260 261 /* Verify checksum and QOP. */ 262 maj_stat = gss_verify_mic_mbuf(&min_stat, ctx, 263 message, mic, &qop_state); 264 m_freem(mic); 265 266 if (maj_stat != GSS_S_COMPLETE || qop_state != qop) { 267 m_freem(message); 268 rpc_gss_log_status("gss_verify_mic", NULL, 269 maj_stat, min_stat); 270 return (FALSE); 271 } 272 } else if (svc == rpc_gss_svc_privacy) { 273 /* Decode databody_priv. */ 274 len = get_uint32(&results); 275 276 /* Decrypt databody. */ 277 message = results; 278 if (len != RNDUP(len)) 279 m_trim(message, len); 280 maj_stat = gss_unwrap_mbuf(&min_stat, ctx, &message, 281 &conf_state, &qop_state); 282 283 /* Verify encryption and QOP. */ 284 if (maj_stat != GSS_S_COMPLETE) { 285 rpc_gss_log_status("gss_unwrap", NULL, 286 maj_stat, min_stat); 287 return (FALSE); 288 } 289 if (qop_state != qop || conf_state != TRUE) { 290 m_freem(results); 291 return (FALSE); 292 } 293 } 294 295 /* Decode rpc_gss_data_t (sequence number + arguments). */ 296 seq_num = get_uint32(&message); 297 298 /* Verify sequence number. */ 299 if (seq_num != seq) { 300 rpc_gss_log_debug("wrong sequence number in databody"); 301 m_freem(message); 302 return (FALSE); 303 } 304 305 *resultsp = message; 306 return (TRUE); 307 } 308 309 #ifdef DEBUG 310 #include <machine/stdarg.h> 311 312 void 313 rpc_gss_log_debug(const char *fmt, ...) 314 { 315 va_list ap; 316 317 va_start(ap, fmt); 318 printf("rpcsec_gss: "); 319 vprintf(fmt, ap); 320 printf("\n"); 321 va_end(ap); 322 } 323 324 void 325 rpc_gss_log_status(const char *m, gss_OID mech, OM_uint32 maj_stat, OM_uint32 min_stat) 326 { 327 OM_uint32 min; 328 gss_buffer_desc msg; 329 int msg_ctx = 0; 330 331 printf("rpcsec_gss: %s: ", m); 332 333 gss_display_status(&min, maj_stat, GSS_C_GSS_CODE, GSS_C_NULL_OID, 334 &msg_ctx, &msg); 335 printf("%s - ", (char *)msg.value); 336 gss_release_buffer(&min, &msg); 337 338 gss_display_status(&min, min_stat, GSS_C_MECH_CODE, mech, 339 &msg_ctx, &msg); 340 printf("%s\n", (char *)msg.value); 341 gss_release_buffer(&min, &msg); 342 } 343 344 #else 345 346 void 347 rpc_gss_log_debug(__unused const char *fmt, ...) 348 { 349 } 350 351 void 352 rpc_gss_log_status(__unused const char *m, __unused gss_OID mech, 353 __unused OM_uint32 maj_stat, __unused OM_uint32 min_stat) 354 { 355 } 356 357 #endif 358 359 360